Download 3. Surgery: Text-book for English medium medical students / SI

MINISTRY OF PUBLIC HEALTH OF UKRAINE
BUKOVINIAN STATE MEDICAL UNIVERSITY
APPROVED
on the cathedral meeting of the
Department of patient care and higher nurse education
"______"___________________200___.
minute № ____
Head of department
Associate professor
Plesh I.A.
METHODICAL GUIDELINES
for 3 – year students of the medical faculty
rd
MODULE 2
THE MAIN DUTIES AND PROFESSIONAL SKILLS OF NURSE
AT THE SURGICAL DEPARTMENT
SEMANTIC MODULE 1
HAEMOSTASIS. BLOOD TRANSFUSION.
RESUSCITATION IN SURGICAL PATIENTS.
Topic:
Reanimation in surgical patients
Subject: Nursing practice
3rd-year students of Medical faculty
Speciality: "General medicine" – 7.110101
7.110104 – "Pediatrics"
Duration - 1 hour
Methodical guidelines composed by:
Professor R.I. Sydorchuk
Assoc. professor O.Y. Khomko
Assistant R.P. Knut
Chernivtsi – 2008
AIM: To carry out reanimation actions in surgical patients.
PROFESSIONAL MOTIVATION: Achievements of modern anesthesiology
especially in general anesthesia with use of miorelaxation let surgeons to perform
very complicated and traumatic operations.
Sometimes during or after the anesthesia unexpected dysfunctions, damage
of organs and tissues can occur. These dysfunctions can serve as a reason of hard
complications development or can lead to patient's death. Complications can occur
in any kind of anesthesia as a dysfunction of vital organs and systems what can
lead to the death of the patient. Knowing of these complications, ability to
diagnose, prevent them and provide the first aid to the patient in time can save the
patient's life.
Decrease of the pain sensitivity and or its full cutoff during performing of
operative interventions and treatment without decrease of the consciousness lets
surgeon to perform the operation qualitatively and to avoid the harmful influence
of general anesthetics.
All doctors in their practical work face a necessity to provide a patient the
first aid due to one or another terminal state. This is especially characteristic for
doctors working in surgical specialties.
BASIC LEVEL:
Technique for local anaesthesia
The equipment necessary for local anaesthesia need not be elaborate, but it
must be kept in good condition at all times. Lock type glass syringes of 5ml and
10ml capacity, with metal tips, are the most satisfactory. Metal rings for the
fingers, permitting a firmer grip and better control of the syringe, are preferred
(Fig.1 a,b ). Needles must be selected carefully.
Beveled point of needle is used for the initial skin wheal or endodermic
infiltration. Longer needles should be available for deep infiltration and nerve
blocks.
Syringes and needles must be cleansed thoroughly after use and sterilized for
subsequent use.
Fig 1. (a) The initial skin-wheal (like skin of lemon) is made by the short 25-gauge
needle. The needle is inserted with the level parallel to the skin surface and the
anaesthetic solution is injected as the needle is carried through the skin tissues. In
this way there is little discomfort associated with the injection, (b) Infiltration of
the deeper tissues is carried out with the long needle, which is always inserted
through skin areas that have previously been anaesthetised. Injection of the
anaesthetic solution is made as the needle advances
Local anaesthesia is produced most commonly by the direct infiltration of
the tissues with the anaesthetic solution. Thus, suitable anaesthesia may be
obtained for superficial tumors, cysts, thrombosed external haemorrhoids and a
number of other superficial lesions.
Acute fractures may be reduced easily after the direct infiltration of the
haematoma about the fracture site with the anaesthetic solution. Superficial
infections, contrary to general opinion, may be opened under local anaesthesia by
infiltration of the skin along the line of the proposed incision without fear of
spreading the infection.
Procaine hydrochloride 0.5% is used for local infiltration for removing
superficial lesions, suturing small wounds, skin grafting and incising superficial
abscesses. An initial skin wheal is first made, using the small 25-gauge
hypodermic needle. The point of the needle is inserted with the bevel down
directly into the skin. In places where the skin is loose, it should be held under
tension during this.
Injection. The anaesthetic solution is injected as the needle is inserted into
the skin. Thus a cutaneous wheal, which shouldbe about 1 cm in diameter, is
produced with little or no pain to the patient. Then a longer needle is attached to
the syringe, inserted through the anaesthetized skin at the site of the wheal, and a
subcutaneous linear or elliptical line of infiltration is produced; or the intradermal
infiltration may be continued from the original wheal. When the infiltration is to be
continued subcutaneously, it may be necessary to make more than one cutaneous
wheal; or, better still, the longer needle may be inserted into the cutaneous layer
from beneath, at the end of the subcutaneous infiltration, a wheal produced, and the
subcutaneous infiltration continued further by reinserting the needle through this
wheal.
Infiltration of the skin along the line of proposed incision of a superficial
abscess will not spread the infection if adequate drainage is obtained, and the
abscess may be opened with no discomfort to the patient if pain produced by
pressure is prevented. Incision and drainage of superficial abscesses may be easily
performed. After the skin has been anaesthetized it is grasped with a towel clip or
between 2 towel clips and lifted up while the incision is made . Thus deep pressure
over the inflamed area is avoided, and painless incision can be performed, since the
skin has been anaesthetized. No epinephrine is used in the anaesthetic solution.
Anaesthesia for the reduction of acute fractures of any of the bones of the
extremities may be obtained readily by the direct infiltration of a local anaesthetic
solution at the fracture site . The longer 2-in. or 3-in. needle is introduced through
one or more skin wheals toward the fracture line, avoiding the larger vessels and
nerves.
After contacting the bone, the needle may be partially withdrawn and
reinserted until aspiration of bloody fluid indicates that the haematoma about the
fracture has been reached. Occasionally, one may be able to feel the needle slip
between the bone fragments at the line of fracture. The fact that bloody fluid may
be aspirated at several levels indicates that the haematoma has been pierced, rather
than that an accidental venipuncture has been performed. The blood aspirated from
a haematoma of several hours duration may aiso be identified by its dark
appearance.
Fig.2. Local anaesthesia in the reduction of fractures. The long needle is inserted
through an initial skin wheal until bloody fluid can be aspirated or the tip of the
needle itself slips between the bony fragments. The anaesthetic solution is then
injected into the hematoma at the fracture site
Procaine hydrochloride in I or 2% solution, preferably with epinephrine, is
used for the infiltration about a fracture. Not more than 30 ml of the 2% solution or
more than 60 mi of the 1% solution should be used routinely, and the injection
always should be performed slowly and cautiously in order to avoid systemic
reactions. Full anaesthesia is not obtained until at least 15 minutes after the
injection.
The best results with infiltration anaesthesia for the reduction of fractures are
obtained with early, acute fractures. After from 48 to 72 hours, the haematoma
about the fracture site becomes organised, making it more difficult to obtain
satisfactory infiltration. However, this anaesthesia may be used with almost any
fracture of less than 48 hours duration and is the most efficient anaesthesia in such
cases. Reduction may be performed safely under roentgenoscopic guidance and the
full cooperation of the patient maintained throughout the procedure; this greatly
facilitates the reduction and the subsequent application of splints or plaster casts
for immobilization. It is a distinct advantage in the reduction of fractures in a dark
fluoroscopic room and at times when an anaesthetist is not available. It is the
anaesthesia of choice for the reduction of fractures in ambulatory patients.
Field block Diffuse infiltration of an anaesthetic solution through all tissues
containing sensory nerves leading from the field of proposed operative intervention
effectively blocks sensory impulses in these nerves and their branches. Anaesthesia
of the operative field is thus produced without direct infiltration at the operative
site. This is known as field-block anaesthesia and is an intermediate procedure
between purely local infiltration and nerve block. A wider zone of anaesthesia,
which usually lasts longer, may be obtained with smaller quantities of anaesthetic
solution than would be required for local infiltration of the entire operative field. In
addition, it requires less technical skill than nerve block and therefore may be used
to advantage when the operative site is supplied by a number of small sensory
nerves.
A field-block type of anaesthesia may be preferred to direct local infiltration
for the removal of sebaceous cysts, lipomas, benign tumors and other superficial
lesions of the body surface, as the tissue at the site of operation are not distorted by
infiltration with the anaesthetic solution. The anaesthetic solution is injected into
the skin and subcutaneous tissues through an initial skin-wheal to form an elliptical
or diamond-shaped zone of infiltration round the operative field. Procaine
hydrochloride 0.75 or 1% should be used for this type of anaesthesia .
The Scalp. Anaesthesia of the scalp may be obtained by a zone of infiltration
encircling the lesion, since all the sensory nerves pass upward in the subcutaneous
tissues. Thus any portion of the scalp may be anaesthetized conveniently by a field
block with 0.5 - 1% procaine hydrochloride .
The Neck. The majority of operations about the neck on ambulatory patients
may be accomplished by the use of local infiltration anaesthesia. Deep cervical
block, which may be used for more extensive operations, is not indicated, although
superficial cervical block, a form of field-block anaesthesia, may be useful
occasionally in conjunction with local infiltration. The superficial branches of the
cervical plexus may beblocked as they cross over the posterior border of the
sternocleidomastoid muscle. 20-30 ml of 0.5% procaine are injected on the
posterior border of this muscle where the superficial jugular vein crosses it.
Phrenic nerve block is one of the most useful and practical therapeutic
blocks for the treatment of intractable hiccups and may be of value in the
ambulatory patient. The phrenic nerve arises from the anterior primary division of
the 4th cervical nerve and receives fibers from the 3rd and the 5th cervical nerves.
The 3 components join together and descend as the main nerve trunk, crossing over
the anterior scalenus muscle. The nerve may be blocked as it crosses the anterior
surface of the muscle. With the patient in the supine position and head turned to
the opposite side, the posterior border of the sternocleidomastoid muscle is
palpated with the index finger. A skin-wheal is raised 3 cm above the clavicle on
the posterior border of the sternocleidomastoid muscle. The anterior scalenus
muscle is situated lateral and posterior to the sternocleidomastoid. A 22-gauge
short beveled needle is inserted through the wheal and advanced posteromedially
until the fascia of the anterior scalenus muscle is pierced. This is usually al a depth
of 1 in. From 10 - 15 ml of \% solution of procaine with or without epinephrine is
injected slowly. Anaesthesia is established in 10 - 15 minutes.
The Thoracic Wall. Any desired area of the thorax may be blocked by
simple infiltration of all its layers with a 0.5% solution of procaine. Wider areas of
anaesthesia may be produced by intercostal nerve block. Wheals are raised in the
midaxillary line along the inferior border of the desired ribs.
A 5 cm needle is introduced through the wheals until the rib is contacted. It
is then withdrawn slightly and reintroduced, passing beneath the lower border of
the rib in a cephalic direction. It is advanced 0.5 cm beyond the rib border. After
aspiration, 4 ml of 2% procaine is injected at this site (Fig.3). To complete the
block it may be necessary to infiltrate the skin and subcutaneous tissues with 0.5%
procaine.
Fig. 3. Intercostal nerve block. The clotted figure shows the position of the needle
as it is introduced through a cutaneous wheal until the rib is contacted. The needle
then is withdrawn slightly and reintroduced so that it passes just beneath the lower
border of the rib. At this point r/te anaesthetic solution is injected
The Abdominal Wall. Rarely will it be necessary to provide extensive
abdominal wall anaesthesia for the ambulatory patient. Infiltration of the layers of
the abdominal wall with procaine will produce satisfactory anaesthesia. Abdominal
field block for operations of greater magnitude may be produced by the injection of
the thoracic nerves as they traverse the abdominal wall. With the patient lying in
the supine position, skin-wheals are raised over the xiphoid process, at the point
along the 10th costal cartilage where the lateral border of the rectus abdominis
muscle crosses it (on the side of the abdomen to be anaesthetized) and along the
lateral border of the rectus abdominis muscle a few centimeters above and below
the umbilicus. An 8 cm needle is passed through these wheals to join them together
in straight lines by subcutaneous injections of 0.5% procaine. The needle is again
passed through each wheal towards the fascia of the rectus muscle. Procaine is
injected as the needle pierces the superficial fascia and then passes through the
fascia of the rectus muscle. Injection of several milliliters is made into the muscle.
The position of the needle is then changed in fanlike manner and repeated
injections are made into the muscle.
The Penis. Block anaesthesia for circumcision or other operations on the
penis may be obtained by a subcutaneous injection encircling the base of the penis,
supplemented by the injection of 1 - 2 cc. of 1% procaine beneath the fascia
(Buck's) on each side. Procaine solution of I or 2% should be used .
For circumcision, a simple form of infiltration anaesthesia is practiced more
commonly. With 1% procaine solution, the foreskin is reflected. and a circle of
infiltration anaesthesia is deposited under the skin, close to the edge of the glans.
Special care must be taken to infiltrate the frenulum, in which there is a rich plexus
of sensory nerves. After this infiltration has been completed, the foreskin is
replaced over the glans, and a second circle of infiltration is made in the skin at the
same level at the base of the glans. This dual infiltration is not time consuming and
gives excellent anaesthesia. In cases in which the foreskin cannot be retracted
easily, the superficial skin anaesthesia is induced first, and then the anaesthetic is
carried deeper into the foreskin near the edge of the glans. A line of infiltration is
injected downward to the edge of the foreskin. With this anaesthesia it is possible
to incise the edge of the foreskin sufficiently to permit retraction and the
completion of the anaesthesia.
The Amis and the Rectum. The sensory nerves which go to the anal canal
and the anal orifice may be blocked easily, as they traverse the fatty tissues of the
ischiorectal fossa. These nerves arise from the perineal nerve as it passes in
Alcock's canal along the ramus of the pubis. They traverse the ischiorectal fossa
from behind, forward and medially, to reach the anal canal. In addition, there are a
few small so called coccygeal nerves which pass directly forward from the region
of the coccyx to the anal canal. Therefore, it is possible to block completely all the
nerves which reach the anal canal by introducing a wall of anaesthetic solution
outside it in the ischiorectal fossa.This is accomplished best with 2 injections. The
first is an infiltration anaesthesia into the skin of the perianal region, usually
performed with \% procaine solution containing epinephrine. It may be injected
without fear of subsequent infection if the area has been cleaned with soap and
water and followed by the application of one of the commonly used antiseptic
solutions. The local infiltration is begun at the midline posteriorly and is carried
laterally on each side to anesthetize completely the skin surrounding the anal
orifice. After skin infiltration, a deeper injection must be made to block the nerves
as they traverse the ischiorectal fossa. Since these nerves pass from behind,
forward and mesially, it is most important that the anaesthetic solution be
introduced round the posterior half of the circumference of the anal canal. With the
index finger of the left hand introduced through the anal orifice, the injection is
begun just to the lateral side of the midline. The patient should be warned of some
slight feeling of discomfort as the needle is introduced deeply into the ischiorectal
fossa. Failure to give this warning may cause the patient undue apprehension, and,
if he moves, considerable difficulty may ensue, even to puncturing the anal canal
or the rectum with the needle. The needle is carried in a fanlike direction round the
anal canal, forward and backward. The injection is made at a distance of about 0.5
in. to 1 in. away from the canal, the nerves being blocked as they .approach the
canal itself. It should be earned throughout the entire length of the anal canal,
about 20 ml of 1% procaine being used on each side. Occasionally, it is necessary
to make an anterior injection.
In making these injections into the ischiorectal fossa for block of the nerves
to the anal canal, it is important that only a small amount of the solution be
deposited in one place. The needle must be kept moving practically all the time and
the injection made continuously. If too much solution is deposited at any one place,
a painful slough may result.
Local infiltration produces almost immediate anaesthesia and causes
relatively slight distortion. The addition of epinephrine, 3 drops of the 1:1,000
solution to the ounce of anaesthetic solution (30 ml), not only prolongs the
anaesthetic effect but also markedly reduces the amount of bleeding. This type of
anaesthesia is especially valuable for anal-fissure operations, haemorrhoidectomy,
the removal of anal polyps and anal crypts. It may be contraindicated in infected
areas, such as abscesses and complicated fistulas. The incidence of postoperative
urinary retention following anal operations is less after local infiltration and block
anaesthesia than after any of the other anaesthetics used for anal operations.
Conduction Anaesthesia (Nerve Block)
Sensory anaesthesia may be produced by the injection of an anaesthetic
solution into or immediately round the nerve or a plexus of nerves. Long lasting
anaesthesia of a rather large area with a minimum amount of drug is the chief
advantage of nerve block anaesthesia. Its only disadvantage is that a fair degree of
technical skill and experience is required to master the various nerve block
procedures. With increasing experience, however, one will find a few of the
various types of nerve blocks very useful and suitable for operations on ambulatory
patients.
Digital Nerve Block. The dorsal and the volar digital nerves may be blocked
within the soft tissues at the base of the fingers or the toes for operations on the
digits. Intradermal wheals are raised on each side, at the base of the digits, and the
needle is introduced into the deeper tissues through these wheals.
The anaesthetic solution is deposited close to the bone, near the anterior and
the posterior digital nerves. From 3 to 5 ml of 1 % procaine will produce adequate
anaesthesia. It must be remembered that with a digital block or any other type of
conduction anaesthesia, one must wait a short time for the full anaesthetic effect.
Usually, from 5 to 10 minutes must elapse from the time of injection for complete
anaesthesia of the digit. A tourniquet may be applied at the base of the digit
(rubber band) to control bleeding. Epinephrine is usually omitted.
Wrist Block. Anaesthesia for operations on the hand may be obtained by a
block of the sensory nerves at the wrist. Perineural infiltration of the nerves,
particularly of the radial nerve, is usually performed, since it is almost impossible
to block each sensory fiber innervating the hand. The superficial sensory branches
which join the main nerve trunks higher in the forearm are blocked by a
subcutaneous bracelet injection about the wrist.
The median nerve is superficial in the wrist and may be located easily. It lies
just to the radial side of the flexor digitorum sublimes muscle and directly beneath
and between the tendons of the palmaris
\ongus and the flexor carpi radialis. These superficial tendons, which can be
seen or palpated easily, serve as the landmarks for the injection of the median
nerve. A 2 in. needle, inserted through an intradermal wheal, should be directed
between these tendons on a line with the tip of the ulnar styloid. Then the needle is
inserted downward at right angles to the skin and slightly toward the radial side of
the wrist for a distance of 0.5 cm. If paresthesias are obtained in the thumb or the
index finger, the needle should be immobilized and 5 ml of 1% procaine injected.
Best results are obtained if paresthesias are elicited before injection. If paresthesias
are not obtained, 5-10 ml of procaine should be infiltrated after the needle has
reached a depth of 0.5 cm.
Epidural anaesthesia
Epidural anaesthesia follows the deposition of a local anaesthetic agent into
the extradural space within the vertebral canal. When anaesthesia of caudal, sacral,
or low lumbar dermatomes is indicated, the sacrococcygeal hiatus is a convenient
approach to the epidural space. This is called caudal anaesthesia, a technique
useful in perineal and rectal operations and for pain relief in the terminal stages of
labor and delivery.
Thoracic and cervical epidural blocks are not used as often because the
epidural space is narrow and the risk of injury to the cord is greater. The site of
action of local anaesthetics injected into the epidural space is in doubt, but in all
likelihood it is at the point where the nerves lose their dural sleeves at the
intervertebral foramina. Some contend that the site of action is central to the pia
arachnoid because an appreciable concentration of local anaesthetic is detectable in
CSF after epidural block.
Spinal anaesthesia
Spinal anaesthesia results from the injection of a local anaesthetic into the
CSF so that the drug bathes the origin of the peripheral nerve roots.
Puncture of the dural sac in the low lumbar area can be performed easily. In
this area the sac is about 15 mm in diameter, narrowing as it extends caudally to
terminate at the level of the second sacral vertebra. The area between L2 and L4 is
nearly always chosen for lumbar puncture, since the spinal cord terminates
between the LI and L2 vertebral bodies and the risk of cord puncture is negligible
below this level.
The specific gravity of CSF is 1.006. About 90% of spinal anaesthetic
procedures in the United States are performed using hyperbaric techniques, with
10% dextrose providing the greater specific gravity.
Spinal anaesthesia is an excellent choice for patients who have eaten
recently because the protective pharyngeal reflexes are intact in case vomiting
should occur.
Introduction of spinal anaesthesia requires a hollow needle 8-1 0 cm long
with a mandrin inserted into its lumen, a 5 - 10 ml syringe, thumb forceps for
grasping the gauze or cotton while disinfecting the skin, and collodion. A 5%
novocain solution and 1 % sovcain (nupercain) solution are most frequently used
as anaesthetics. This anaesthesia is introduced as follows. The patient is seated on a
table so that his legs rest on a stool placed next to the table and his elbows on his
knees. He is asked to curve his back. The skin of the back along the line of the
vertebral spinous processes is disinfected with alcohol. The space between the
fourth and fifth lumbar vertebrae is found and the needle is inserted in it to a depth
of 6 - 8 cm. After this mandrin is removed. If the needle has penetrated into the
spinal canal, the CSF begins to flow out in drops. If no CSF flows out or blood
appears instead, it means that the tip of the needle has not penetrated into the spinal
canal or has injured, a blood vessel. The needle must be removed and an attempt
made to reintroduce it. After several drops of the CSF have flown out, the syringe
filled with 2 ml of a 5% novocain solution or 0 - 5 ml of a 1% sovcain solution is
attached to the needle. The syringe slowly aspirates 1 - 2 ml of the CSF, which
mixes with the anaesthetic solution. Then the mixture is slowly administered into
the spinal canal, the needle is removed and the site of the puncture is pasted with
collodion. The patient is placed in a supine position. Within 5 - 10 minutes the
patient loses sensitivity of the part of the body below the injection. If the patient is
in a position with raised pelvis and lowered head, anaesthesia also spreads above
the level of the injection. Today spinal anaesthesia is used along the entire spine,
which makes it possible to perform operations on the trunk. Spinal anaesthesia in
the region of the thorax is known as'High Level anaesthesia.
While spinal anaesthesia has certain advantages, it also has its shortcomings.
It cannot be considered safe because the anaesthetic administered into the spinal
canal may, by reaching the medulla oblongata, produce paralysis of the vitally
important nerve centres of respiration and blood circulation.
Puncture of the dural sac and injection of foreign substances into the CSF
can be dangerous. Even without injection, lumbar puncture produces local trauma,
changes CSF dynamics, and may lead to the introduction of infection into the
subarachnoid space.
This is usually preceded by extreme pallor, nausea, vomiting, fall of BP and
respiratory arrest. Particularly frequent are the complications in high-level spinal
anaesthesia in the thoracic part of the spinal canal, administered for operations in
the upper part of the abdominal cavity. After spinal anaesthesia the patient's head is
therefore immediately placed on a bolster with the neck bent so that the chin
touches the chest. Forming an angle between the axis of the body and the head this
position of the patient prevents the anaesthetic solution from spreading upward
along the spinal canal and, consequently, from acting on the medulla oblongata.
More over, during spinal anaesthesia the patients are under no circumstances
allowed abruptly to change their position, especially to assume a sitting or even
half-Sitting position. It should also be remembered that, when complications occur,
raising the head does not eliminate but, on the contrary, increases the symptoms.
The best method, if a complication has developed, is complete rest and repeated
subcutaneous administration of caffeine, ephedrine or lobeline. Caffeine
administered before the operation is useful as a prophylaxis, whereas morphine, on
the contrary, should not be administered before the operation. After spinal
anaesthesia patients not infrequently have headaches and vomit. Under sovcaine
anaesthesia cyanosis and respiratory disturbances are observed and I ml of 5%
ephedrine solution should be administered 10-1 5 minutes before introducing this
form of anaesthesia. Spinal anaesthesia by sovcaine which lowers the BP is
contraindicated for operations necessitated by trauma and internal haemorrhages.
Intravenous regional anaesthesia follows the injection of a large volume of
dilute local anaesthetic solution into the vein of a bloodless extremity, the solution
confined to the extremity, by a tourniquet.
General Anaesthesia
Modem general anaesthesia is aimed at producing a temporary state of
unconsciousness in the patient (narcotic sleep) and diminution or complete relief of
sensitivity to pain (analgesia). General anaesthetics produce unconsciousness and
varying degrees of analgesia and muscular relaxation. Many of them produce
analgesia before loss of consciousness and continue their analgesic effect after loss
of consciousness, so that sudden painful stimuli do not break through to produce
refiex physiological changes that may reduce the safety of the operative procedure.
No substances in medicine have contributed more to human comfort than the
anaesthetics. They have made modern surgery possible and have transformed the
operating room from a place of misery to one of tranquility and peace.
Anaesthesia is produced by progressively increasing the amount of the
anaesthetic in the inspired air and thus in the blood and brain. Loss of
consciousness is one of its primary prerequisites. It results from the reversible
reduction of the activity in the reticular activating system. This prevents the
activation of the cortex and thus induces loss of consciousness. It can be produced
by a variety of chemical agents that act on the brain.
The administration of an anaesthetic results in progressive depression of the
CNS, which may be preceded by varying degrees of excitation. These drugs first
depress the cerebral cortex via the RAS (reticular activating system) and then the
basal ganglia and cerebellum. This is followed first by sensory and then motor
paralysis of the functions of the spinal cord from below upward. It is known,
however, that there are two afferent systems that carry information to the brain.
The lateral ascending sensory pathways rapidly conduct afferent impulses to
primary receiving areas in the brain by means of fibers that are specific with
respect to modality and topography. The medial multisynaptic ascending pathways
in the core of the brainstem serve as a second and nonspecific sensory system,
which is important in the regulation of consciousness and valuable in the
integration of CNS function. Collaterals from the primary lateral pathways carry
impulses to this system, called the Ascending Reticular Activating System, in
which conduction is slow and diffuse transmission. Peripheral and cortical
impulses converge and interact, and modalities lose their individuality. This system
projects to wide areas of the cortex and promotes wakefulness and alertness.
Experimental interruption of the ascending reticular activating system results in
somnolence or unconsciousness, although sensory conduction via the classic
sensory pathways remains intact. The analgesic effects of subanaesthetic doses of
some volatile liquid anaesthetics and nitrous oxide may indicate a site of action in
the limbic system or in the rhinencephalon at doses insufficient to affect the
reticular system.
Relaxation of skeletal muscles, essential for carrying out certain operations,
may be achieved by deep anaesthesia but only for a short time since such
anaesthesia is dangerous. It is replaced by a more superficial anaesthesia involving
introduction of drugs which reduce muscle tension (relaxants). Other factors which
cause a drop in body temperature and BP, etc., are employed along with the
relaxants to produce a deeper analgesic effect of the anaesthetic and prevent
undesirable side-effects (potentiated anaesthesia). When relaxants are administered
such vital function as respiration is arrested deliberately and artificial respiration is
employed (controlled ventilation).
Stages of Anaesthesia. 4 stages of anaesthesia are distinguished.
1. The first stage (stage of analgesia) is characterized by partial
unconsciousness and diminution of sensitivity to pain. Momentary operations may
be performed during this period. Consciousness is gained quickly when the
anaesthesia will be discontinued.
2. The second stage (stage of excitement) is extremely manifested in males,
particularly in alcoholics. The possibility of concomitant vomiting makes it
dangerous. The latter usually does not occur if the patient has been properly
prepared for the anaesthesia, or when the anaesthesia is produced by cyclopropane,
nitrous oxide, or by intravenous injections of hexenal (hexobarbital) and pentorhaJ
(thiopental).
3. The third stage (surgical) is divided into four planes. The first plane is
characterized by superficial anaesthesia (the patient being unconscious), loss of
sensitivity to pain, a good pulse, and arterial pressure of the same level as before
anaesthesia. The pupils are narrowed, the reaction to light and the corneal reflex
are retained, and involuntary rapid movements of the eyeballs (nystagmus) occur.
The second plane develops as the anaesthesia deepens. Cessation of eyeball
movement, constriction of the pupils and their sluggish reaction to light are
characteristic of this period. Anaesthesia is conducted in these two planes when
relaxants are employed. The third plane which corresponds to deep anaesthesia is
the threshold depth of anaesthesia. Its features are calm and deep respiration, a
rhythmical and not frequent pulse, and the absence of the corneal reflex. The pupils
are slightly dilatated and their reaction to light is weakened. Anaesthesia is
conducted in this plane when relaxants are employed. The fourth plane occurs only
when an excess dose of anaesthetics is administered. During this plane the pupils
dilate, respiration becomes shallow and diaphragmatic, and cyanosis develops
frequently.
4. The fourth stage (agonal) is that of respiratory paralysis and subsequent
cardiac arrest. It is characterized by dilated pupils, which do not react to light,
dryness of the cornea, disappearance of all reflexes, and complete muscular
relaxation. Anaesthesia should never reach this stage. The period of recovery is
also distinguished (it is of long duration only in operations performed over a long
period of time). During this period anaesthesia becomes more superficial, the
tongue tends to fall back, and excitation, vomiting, and respiratory disorders may
occur. The patient must be under continuous observation during this period.
Combinations of several anaesthetics (mixed anaesthesia) or of several methods
(combined anaesthesia) are employed. According to the method of introduction of
the anaesthetic two types of general anaesthesia are distinguished. In inhalation
anaesthesia the anaesthetic is introduced into the lungs together with the inspired
air, it is absorbed by blood from the lungs and affects the CNS. In non-inhalation
anaesthesia the agent is introduced intravenously or it is absorbed in the rectum.
The patient is prepared psychologically for the anaesthesia by a talk the
purpose of which is to assure him that there is no danger of «not awakening», a
thought which, not infrequently, patients carry in their minds. The oral cavity is
prepared by extracting all loose teeth and roots, treating bad teeth, and taking out
all removable dentures. The patient's stomach must be empty during anaesthesia,
for this reason only sweet tea is allowed 3 or 4 hours before the operation. In
urgent surgery the stomach must be emptied with the aid of a stomach lube. In
routine operations the intestines are emptied on the day preceding the operation by
applying an enema. Before the operation the patient must urinate or the urine
should be withdrawn with a catheter.
Great importance is attached to preoperative medication (premedication) of
the patient. To ease the course of anaesthesia and to comfort the patient, adults are
given a somnifacient on the day preceding the operation: nembutal (pentobarbital
sodium) 0.2 g, veronal 0.3 - 0.5 g, medinal 0.3 - 0.6 g, luminal 0.1 g, or barbamyl
(amytal sodium) 0.1 -0.2 g. The drug may be given again 2 hours before the
operation. An analgesic, I ml of a 1% morphine solution or, preferably, 1 ml of a
1% or 2% promedole solution, is introduced subcutaneously 1-1.5 hours before the
operation. A subcutaneous injection of 1 or 2 ml of a 0.5% atropine solution is also
prescribed. Dimedrol (diphenhydramine) 0.03 -0.05 g, diprozine 0.01-0.025 g, or
aminazine (chlorpromazine) 0.025 -0.05 g, is sometimes given per os on the day
preceding the operation.
Inhalation Anaesthesia
Comparison of strength of surgical stimulus and observation of intensity of
response allow a before hand evaluation of specific anaesthetic requirements. More
inhalation anaesthetic may be administered with recognition that this will increase
depression in all components; alternatively, a specific drug, such as a muscle
relaxant, may be chosen to correct a specific defect. The anaesthesiologist may
increase or reduce inhaled concentration of anaesthetic in order to observe the
effect.
General Anaesthetic agents-Nitrous oxide, the first anaesthetic drug to be
used clinically, is still chosen for most general anaesthesias administered today. An
alternative approach, called balanced anaesthesia, employs narcotics, barbiturates,
or tranquilizers to supplement nitrous oxide administered by inhalation. Muscle
relaxant drugs are used with both techniques as required to facilitate surgical
access to the operative site.
Four principal methods of inhalation anaesthesia are distinguished: open
(open drop method), semi - open, semi - closed, and closed.
1. In the open method the anaesthetic (ether as a rule) is inhaled together
with the surrounding air through a simple mask. Part of the agent, not absorbed in
the lungs, is exhaled. This method is rarely employed nowadays, and is used only
if other methods cannot be applied, i.e., in the absence of apparatus.
2. The semi-open method uses apparatus in which the anaesthetic flows from
a closed system (a tank containing nitrous oxide or an ether evaporator) together
with oxygen. Part of the mixture, not absorbed in the lungs, is exhaled into the air.
3. In the semi-dosed method the gaseous mixture also flows from a closed
system comprising of tanks and apparatus. Part of the exhaied mixture is
eliminated, while the remaining pan returns into the apparatus where the carbon
dioxide is removed from it in an absorber and the purified mixture again enters the
lungs.
4. The closed method of anaesthesia is the most widely used. In this
technique the anaesthetic together with oxygen is contained in the closed system
and on being exhaled remains inside this system and is rebreathed. There is a
special device (an absorber containing soda lime) for removing carbon dioxide
from the air exhaled by the patient. In this method the anaesthetic together with
oxygen may be administered through a mask which covers the patient's mouth and
nose - the mask technique. But it is most convenient to administer the anaesthetic
immediately into the trachea through an intubation tube - the intubation technique.
The apparatuses differ in their construction but include the following main
parts: a stand which supports the tanks containing gas (oxygen, nitrous oxide,
cyclopropane, etc.), dosimeters, evaporators, and the breathing system. The tanks
containing oxygen are painted light blue, [hose containing nitrous oxide are grey,
and those of cyclopropane are red (Fig.4).
Fig.4. Oxygen tank and mask for emergency use
Careful watch must be made that the tanks are connected with the
corresponding dosimeters; a fault may result in the patient's death. Oxygen is kept
in the tank under a pressure of 150 atm, and nitrous oxide under 50 atm. When the
gas flows from the tanks into the apparatus the pressure must be lowered to 3 or 4
atm. This is achieved with the aid of a reducing gear attached to each tank The
tanks are opened and closed with a special valve, which is situated at the top end of
the tank. The reducing gear should not be touched. Oxygen, nitrous oxide, and
cyclopropane flowing into the apparatus pass through dosimeters, which show the
number of litres of the gas passing per minute. This ensures accurate dosage of the
gas flow. Each dosimeter is regulated by turning the corresponding handle until the
float in the dosimeter tube reaches the level of the desired pressure (from 0.5 - 10
1/min for oxygen and 1-10 l/min for nitrous oxide). Evaporatoi s are employed for
administering volatile anaesthetics (ether, fluothane). The breathing system of the
apparatus serves for conveying oxygen and the anaesthetic from the dosimeters and
evaporators to the lungs and for eliminating the exhaled mixture. The system
consists of crimped tubes, valves which direct the flow of mixture, a canister of
absorbent chemical for absorbing carbon dioxide (absorber), a T-tube (adapter)
which joins the breathing tubes with the mask or endotracheal tube, a breathing
bag. and bellows. During inhalation or compression of the breathing bag or
bellows the gaseous mixture (oxygen and anaesthetic) flows through the tube
system, adapter, and mask or endotracheal tube and enters the patient's lungs.
During exhalation the gaseous mixture not absorbed in the lungs enters the
breathing bag (stretching it) or the bellows. It is cleared of carbon dioxide when it
passes through the absorber. The absorbent chemical in the absorber is designed
for 3 or 4 hours of work. Administration of general anaesthesia calls for the use of
auxiliary equipment. These include airways, mouth retractors, suction devices,
endotracheal tubes, a connecting T-tube for joining the adapter and endotracheal
tube, anaesthetic forceps, syringes and needles for performing intravenous
injections, and a system for drip blood transfusion and infusion of liquids.
An anaesthesiologisl's assistant must be specially trained in anaesthesiology.
He must be capable of administering anaesthesia both through a mask and through
an apparatus, be able to introduce a tube into the trachea, and administer controlled
ventilation. It is his duty to prepare all the equipment, instruments, and drugs
necessary for conducting anaesthesia. He must also check that oxygen, anaesthetics
in blood, and blood substitutes are available. He changes the soda lime in the
absorber and supplies the anaesthesiologist with all that is necessary for
performing venesection and intravenous blood transfusion. He supervises the
premedication of the patient, his transportation to the operating room and sees that
he is properly placed on the table. From the moment the state of sleep is induced to
the time the patient recovers completely he assists the anaesthesiologist, obeying
his instructions, introducing all drugs necessary in the course of anaesthesia,
making records of the pulse, respiration, BP, and other data on the anaesthetic
chart. After the operation ends the assistant supervises the transportation of the
patient to the ward and, subsequently, keeps the patient under constant observation
as instructed by the anaesthesiologist. He also cleans the apparatus and sterilizes all
the instruments, checks on the drugs spent, and orders and delivers new drugs from
the pharmacy.
Gases. Nitrous oxide is the least potent of the anaesthetic gases, and its
effectiveness is further reduced by the necessity that it should be administered with
at least 20% oxygen. It is non-explosive and does not provide muscle relaxation.
Cyclopropane and ethylene are rarely used today.
Volatile liquids. Halothane (Fluothane) is a potent, noninflammable,
halogenated hydrocarbon with which anaesthesia may be induced smoothly
although relatively slowly. Halothane causes depression of normal ventilatory
responses to carbon dioxide, and respiratory acidosis develops if ventilation is not
supported. The smoothness of induction of anaesthesia, ease of maintenance, lack
of flammability, and pleasentness of recovery have led to wide acceptance of
halothane. Isoflurane (Forane), was synthesized in 1969, it is profound respiratory
depressant and muscular relaxant . Competitive neuromuscular blocking drugs are
markedly potentiated.
Uptake and Distribution of Anaesthetic Agents
The depth of anaesthesia produced by inhalation agents varies according to
the partial pressure of the anaesthetic in brain. This can be controlled only
indirectly. The partial pressure of agents in the brain always attempts to reach
equilibrium with that in arterial blood. If blood gas tension is higher than that in
the brain, anaesthetic agents enter the brain and depth of anaesthesia increases; if
arterial tension is lower than that in brain, the reverse occurs. During induction of
inhalation anaesthesia, the higher the partial pressure of anaesthetic inhaled, the
faster the anaesthetic tension rises in the lung and the faster the arterial tension
rises. When anaesthesia is prolonged, enough anaesthetic agent may be sequestered
in fat deposits to impede normal recovery significantly
The role of the inhalation drugs in general anaesthesia is changing: the
number of patients who receive only inhalation drugs following induction of
general anaesthesia with an intravenous drug is decreasing; the use of intravenous
drugs as adjuvants is increasing. The combination of intravenous and potent
inhaled drugs might be called the new balanced anaesthesia. A variety of drugs are
chosen to derive the specific benefits of each. Thus, tachycardia occurring during
isoflurane anaesthesia may lead the anaesthesiologist to administer an opioid to
take advantage of the specific vagal actions of the opioid and to reduce the dose of
isoflurane. Many anaesthesiologists now prefer to decrease the total dose of a
potent inhaled drug that a patient receives with any one of a number of intravenous
drugs.
The inhaled anaesthetics of greatest importance today are enflurane,
halothane, and isoflurane, the potent drugs, and nitrous oxide, the weaker drug.
Inhalation Anaesthesia Techniques
The different techniques are discussed below :
1. Open drop technique - In the absence of modern equipment anaesthesia is
administered through a simple mask by the open drop technique (usually with
ether). After premedication the patient is placed on an operating table and lied to it.
His face is painted with vaseline to protect the skin from irritation by ether, and his
eyes are covered with thin rubber or a towel. Oxygen will be introduced from the
reducing gear through this catheter. The use of pentothal for the induction of
anaesthesia is desirable. It is preferable to introduce an oropharyngeal or
nasopharyngeal airway for preventing the tongue from dropping back. Ethyl ether
is most frequently used in open drop anaesthesia. This agent is a volatile liquid
which has a characteristic odour, is potently inflammable, and readily explodes
when mixed with oxygen. Ether produces anaesthesia when its fumes constitute 15
- 20% by volume in the inhaled mixture. A 5 - 8% by volume concentration of
ether fumes is sufficient for maintaining anaesthesia The administration of ether is
discontinued 15-20 minutes before the end of the operation. Excitation and
vomiting are of not infrequent occurrence after recovery from anaesthesia
produced by this method. We must say that the technique is used very rarely.
2. Mask-apparatus technique.
Preparing to administer anaesthesia by utilizing an apparatus is necessary to
ground the machine with the help of a cable, fill the absorber with fresh soda lime,
and pour ether into the ether jar. Having opened the valve of the oxygen tank it is
necessary to check whether it contains oxygen in an amount sufficient for
producing anaesthesia. The amount of oxygen contained in the tank is calculated
by multiplying the capacity of the tank (e.g., 10 litres) by the pressure shown on
the reducing gear (e. g., 80 atm). The result is : 80 X 10=800 litres of oxygen. If 4
litres of oxygen will be used per minute the tank will provide for (800/4 = 200
minutes) 3 hours of work. The amount of nitrous oxide may be determined only by
weighing the tank and subtracting from the result obtained the weight of the empty
tank. One kg of nitrous oxide yields 500 litres of gas. The valves of the dosimeters
are opened and the valves of urgent feed are examined. The hermetic properties of
the apparatus are tested by filling the breathing bag with oxygen and pressing on
the bag while covering the opening in the adapter and the safety valve with the
palm of the hand. The hermetic state of the connection of the mask with the
adapter and with the tee tube for the endotracheal tube is also tested. The flow of
oxygen is tested by breathing through the mask. After this the-apparatus is
ventilated by filling the system with oxygen and then emptying it until no ether
odour remains in the mask.
Endotracheal Anaesthesia
For conducting endotracheal anaesthesia the following equipment is
necessary besides the apparatus: a set of laryngoscopes of various sizes (they must
provide free passage and the cuffs must be intact), a set of intubation tubes, a probe
for the lubes, a rubber syringe for inflating the cuffs, and oropharyngeal and
nasopharyngeal airways. The following drugs must be at hand: pentothal. atropine,
promedole, a 0.5% dicaine (tetracaine) solution, and relaxants.
Neuromuscular blocking agents
Muscle Relaxants are agents which reduce tension in the skeletal muscles.
Now, deep general anaesthesia is rarely required; only light planes of anaesthesia
need be provided, and for relaxation the appropriate relaxant drug can be
administered intravenously. Classicaly, the action of muscle relaxants has been
explained by a postsynaptic mechanism. The muscle relaxants are divided into two
classes according to their mode of action. The nondepolarising competitive
blocking agents prevent combination of normally liberated acetylcholine with the
muscle end plate receptores, thereby blocking normal neuromuscular transmission.
D-Tubocurarine, gallamine (Flaxedil) dimethyl tubocurarine (metocurine), and
pancuronium (Pavulon) belong to this group. The depolarising agents combine
with the end-plate receptor to cause an initial but prolonged depolarization of the
postjunctional membrane, resulting in blockade of normal neuromuscular
transmission. The neuromuscular block produced by the competitive agents can be
antagonized by substances that increase the concentration of acetylcholine at the
motor end-plate. An anticholinesterase drug, either pyridostigmine (Mestinon) or
neostigmine (Prostigmin), is used for this purpose and is preceded by a large dose
of atropine to block muscarinic actions such as excessive airway secretions and
bradycardia.
The most widely used are ditiline, listenone and myorelaxant; they are
produced in ampules. Ditiline is introduced intravenously, 8 - 10 ml of a 1%
solution or 4 - 5 ml in a 2% solution. After 15-20 seconds a twitching occurs in the
muscles, and in 20-40 seconds the muscles are completely relaxed and natural
respiration is arrested. For prolongation of its effect ditiline is injected every 5 or 7
minutes (4 - 8 ml of a 1% solution or 2 - 4 ml of a 2% solution) while controlled
ventilation is administered continuously. Relaxants (0.1 - 0.2% ditiline solution)
may be administered by the drip method in a glucose or physiologic solution. A
more prolonged effect (20 - 25 minutes) is exerted by a 2% solution of diplacin
introduced intravenously (8 - 15 ml). The effect of the relaxants is discontinued by
injecting intravenously 1 or 2 ml of a 0.05% proserine (neostigmine) solution.
Anaesthesia Techniques
All equipments and medecines necessary for anaesthesia are placed on a
special anaesthetic table, while all that is required for performing injections is
assembled sterile on a separate table. After being given the usual premedical care
the patient is brought to the operating room and placed on the table in such a
position which allows his head to be lowered. A cuff is fixed on one arm for
measuring the blood pressure, while the other arm is drawn out at not more than a
right angle from the body and placed on a support. It is used for injecting
physiologic solution and glucose, blood transfusion, and for administrating
pentothal, relaxants. If possible, all injections are made into the veins on the back
of the hand, and only if needed cubital veins are used. After being placed in the
proper position the patient is given oxygen to breath through a mask. Intubation is
performed under local anaesthesia or during the induction of anaesthesia with
pentothal and relaxants, introducing 1.2 - 2 mg per 1 kg of body weight, i.e. 100 120 mg in 5 - 10 seconds. When the muscles relax the patient's head is lowered and
thrown back as far as possible. Then the anaesthesiologist inserts the intubation
tube into the larynx under visual control with the aid of a laryngoscope (Fig. 5).
After ditiline has been injected, but before laryngoscopy, controlled ventilation is
administered through the mask. The tube introduced into the larynx is fixed to the
pattern's face with adhesive plaster or a bandage. Then either the cuff is inflated or
tamponade of the patient's mouth and larynx with a bandage is performed. The
tube must only reach the bifurcation of the trachea and in no case may it be
introduced into one of the bronchi. After intubation the tube is connected through
the tee with the adapter of the apparatus and the feed with oxygen and nitrous
oxide or oxygen and ether is begun. Simultaneously artificial respiration is
administered by rhythmically compressing the breathing bag or with the aid of
bellows. Nitrous oxide is most frequently utilised for the induction of endotracheal
anaesthesia. In the beginning anaesthesia is administered by the semi-closed
technique with the absorber connected to the system. To deepen the anaesthesia 1.5
- 2 ml of a 1 %. promedole solution is again injected intravenously, repeating the
injection every 30 - 40 minutes, or 0.5 - I %. by volume of ether is added. Ether
anaesthesia may be carried out without the use of nitrous oxide, the ether
concentration required in this case being much lower (5-7 graduations on the ether
jar at first and then 1 - 3 graduations) than during anaesthesia without relaxants. If
natural respiration appears the relaxant is injected repeatedly (40 - 80 mg of ditiline
every 6-8 minutes). Relaxants are introduced only when the effect of the preceding
injection has worn off, and are discontinued 15-20 minutes before the end of the
operation, natural respiration resuming 8 -10 minutes after the last injection. The
intubation tube is removed only after natural respiration has been completely
restored.
Fig. 5. Equipment for intubation
Modern anaesthesia may be combined with controlled hypotension, i. e.
lowering blood pressure by administering ganglion blocking agents [hexonium
(hexamethonium), pentamine, deep fluothanc anaesthesia] and with artificial
hibernation induced by neuroplegics [large doses of aminazine (chlorpromazine).
Nitrous Oxide Anaesthesia. This requires adequate premedication, but
eveifnso it may be incomplete in strong patients and will not ensure complete
muscle relaxation, or this reason more potent anaesthetics must be added (ether and
muscle relaxants. Nitrous oxide is a colourless combustible gas devoid of odour.
For anaesthesia it is always given mixed with oxygen. It does not irritate the
respiratory tract and is rapidly eliminated from the body. In a concentration of 50 60 %. it produces analgesia, and a concentration of 80 - 90 %, gives rise to
unconsciousness and the surgical stage of anaesthesia. To attain a deeper analgesia
promedole is added in portions intravenously. The working condition of the
apparatus and the amount of oxygen and nitrous oxide contained in it must also be
checked in this technique. A hot-water bottle is tied to the reducing gear to prevent
freezing when the nitrous oxide evaporates. The breathing system is filled with
oxygen, the absorber is switched off, and the patient is fed pure oxygen at a rale of
8 - 10 1/roin for 2 -3 minutes. After checking that the mask permits no passage of
the surrounding air the amount of oxygen is reduced to I 1/min and the patient is
fed nitrous oxide at a rate of 9 - 12 1/min. In 1 - 1.5 minutes the patient loses
consciousness and becomes slightly excited. A 9 : 1 or 12: 1 ratio of nitrous oxide
and oxygen is retained for another 1-1.5 minutes, and then the amount of nitrous
oxide is reduced to 6 -8 1/min, and that of oxygen is increased to 1.5 - 2 1/min. The
absorber is switched on and anaesthesia is continued with this proportion of gases
(4 : i). Three or five minutes before the end of the operation the nitrous oxide
concentration is reduced and the patient is fed pure oxygen. The flow of nitrous
oxide and oxygen must not be discontinued simultaneously. Recovery from this
type of anaesthesia is very rapid, in 1-2- 3 minutes.
Fluothane Anaesthesia. Fluothane is a colourless volatile liquid with an
unpleasant odour. It is non-inflammable and exploses on being mixed with oxygen.
The state of anaesthesia is produced rapidly almost without a stage of excitation,
and the stage of recovery is very brief. Premedication includes an intramuscular
injection of atropine (0.5 -1.0 mg) administered 20 - 30 minutes before anaesthesia.
If thiopental is used for the induction of anaesthesia, its dose must be reduced. Of
the analgesics it is preferable to use 20 - 30 mg of promedole instead of morphine.
Anaesthesia is administered only by the physician, and the dosage of fluothane
must be very accurate. In short operations anaesthesia may be applied by the open
drop technique, introducing 30 - 40 drops of fluothane per minute in the beginning.
When the surgical stage of anaesthesia is achieved (in about 3 minutes) the dose is
reduced to 10 -12 drops per minute. A slow pulse and fall of arterial pressure are
noted when anaesthesia is produced. Anaesthesia is conducted by the semiopen,
semi-closed, and closed techniques- with a 2 - 3 %. fluothane concentration in the
inhaled mixture. The conceutcatiau is. reduced to I -1.5 % as soon as the surgical
stage is reached. Rapid increase of fluothane concentration is avoided. Fluothane
relaxes the muscles and for this reason relaxants are rarely used. But if the muscle
tension is not sufficiently reduced, the relaxant of choice is ditiline. The main
danger of this type of anaesthesia is the possibility of over dosage. This results in
cessation of respiration with subsequent cardiac arrest and in a fall of blood
pressure. The latter complication is controlled by an intravenous injection of 0.10.3 ml of a 1 %. mesaton solution.
Cyclopropane Anaesthesia. Cyclopropane is a gas delivered in tanks. Used
together with oxygen it produces analgesia in a concentration of 5 - 8 %. by
volume, and the surgical stage of anaesthesia in a concentration of 15 - 18 %. by
volume.. Cyclopropane anaesthesia is administered mainly by the closed
technique, and not infrequently in combination with nitrous oxide: induction of the
anaesthesia is usually performed by intravenous pentothal injection.
Dangers and Complications during General Anaesthesia
A spark appearing as a result of accumulation of static electricity in the
rubber parts of the anaesthetic apparatus may be the cause of an explosion during
work. Explosions may occur when ether or Cyclopropane are used as anaesthetics.
An explosion may be prevented by grounding the apparatus and opening the tank
valve only with the hand or a special wrench. Vaseline and oils should not be
applied to the patient's face. Masks and tubes made of common rubber (black
coloured rubber) which does not conduct electricity must be moistened with water.
An electric knife should not be used during ether or cyclopropane anaesthesia.
Complications. The most frequent complication during ether anaesthesia,
particularly that conducted by the open drop method, is respiratory disorders which
lead to oxygen deficiency (hypoxia). Respiratory disorders may also appear as a
result of shock, cardiovascular insufficiency, blood loss, and other factors. In the
initial stage of hypoxia the pulse is frequent and tense, arterial pressure increases,
respiration accelerates, muscles become tense, and cyanosis appears. Later the
pulse becomes more accelerated and weaker, intensification of cyanosis is
accompanied by disturbances of respiration rhythm, and the pupils dilatate and do
not react to light. Respiratory disorders and hypoxia may also develop as a result of
obstruction of the respiratory tract, faults of the apparatus, and inhibition of the
respiratory centres by the anaesthetic. Obstruction of the respiratory tract is
displayed by exaggerated contractions of the respiratory muscles and drawing in of
the intercostal spaces during inhalation. The most common causes of these
disturbances during mask anaesthesia are the tongue falling back against the
posterior wall of the pharynx, large amounts of mucus, and obstruction of the
trachea with vomitus, particularly if the patient has been inadequately prepared for
the anaesthesia (during urgent operations). The tongue is prevented from falling
back by introducing an airway. The mucus must be wiped away or aspired, and
ether must be fed carefully and in minimum doses. The most frequent faults of the
apparatus are oxygen deficiency, incorrect connection of the tanks with the
dosimeters, lack of air-tightness in the breathing system, bends in the tubes, and
faults in the dosimeters and reducing gear. Respiratory disorders in endotracheal
anaesthesia may be caused by faults in the intubation tube, its incorrect position
(introduction into a bronchus), and twisting of the tube, as well as by unskilful
intubation and careless use of relaxants. Overdosage of the anaesthetic leads to
arrest of respiration (apnoea). Such cases call for controlled ventilation with
oxygen. Respiratory disorders not eliminated in time result in cardiac arrest.
Cardiac massage must be quickly restored (not later than 5 minutes after the
cessation of cardiac activity) in this condition. During anaesthesia, in over dosage
of the anaesthetic in particular, the pulse rate may increase or slow down and
arrhythmia, fall of blood pressure, and other disturbances of cardiovascular activity
may arise. These manifestations call for preventive measures, special treatment
and, first and foremost, normalisation of gas exchange.
Care of the Apparatus. After completion of anaesthesia it is necessary to
blow through the apparatus with oxygen and close the valves on the tanks. The
dosimeters should be opened and when the floats come down to the zero point,
should be closed again. The remnants of ether must be poured out of the jar, and
the latter washed. The soda lime should be removed from the absorber. The mask,
endotracheal tubes, and crimped tubes should be washed both outside and inside
with warm water and soap and dried. The inside surface of the endotracheal tubes
is cleaned with a special wire brush and wiped with a gauze tampon inserted with
the aid of a mandrin. Following this the tubes are submerged into boiling water for
1 - 2 minutes or into 70° alcohol for 2 hours (this somewhat softens the rubber),
dried and stored in a drum. The laryngoscope spatulas and the adapter are also
washed in warm water and soap and are wiped with napkins soaked in alcohol.
Noninhalation Anaesthesia
Intravenous anaesthesia may be administered in a single dose, in repeated
fractional doses, and by the drip method. Although a wide variety of drugs ranging
from diethyl ether to a nonhormonal steroid have been administered intravenously
to produce general anaesthesia, only the ultra-short-acting barbiturates have gained
wide support for use by this route until recently.
Ultra-short-acting barbiturates. The thioba/bitu rates thiopental (Penlothal)
and thiamylal (Supital) are administered intravenously. These drugs are useful
because of two characteristics of the anaesthetic state that they produce; rapid
onset and short duration. Anaesthesia induced by these drugs is associated with
respiratory depression or apnoea if large dose given analgesia or muscle relaxation
is provided. For this reason, the thiobarbiturates are seldom given as the sole
anaesthetic for other than very brief operation.
Ketamin is a parenterally administered phencyclidine derivative used to
produce a state called 'dissociative anaesthesia' Ketamine stimulates the
sympathetic nervous system, causing elevated blood pressure, peripheral
vasoconstriction, cardiac stimulation and increased intra-cranial pressure. It is
contraindicated in patient with intracranial mass lesions but has been used in
combination with nitrous oxide to provide anaesthesia in patients with circulatory
shock.
Introduction of the anaesthetic agent narcolan (avertin) into the rectum
produces rectal anaesthesia. This type of anaesthesia is rarely administered because
of dosage difficulties, and is used mainly in operations on the head and neck. An
enema is applied on the day preceding the operation or on the same day. The
substance is administered in the form of a freshly prepared 3 %. solution heated to
37 - 40°C. Adults are introduced 60 - 80 mg per 1 kg of body weight. Anaesthesia
is produced within 5-1 0 minutes.
Choice of Anaesthesia. The preparation for anaesthesia and the type of
anaesthesia vary depending on the urgency of the operation, the general condition
of the patient |shock, blood loss), condition of his cardiovascular system (heart
diseases, myocardial infraction in the past, etc.) and the presence of pulmonary
diseases (bronchial asthma). The character of the current disease and the age of the
patient (children and aged) are also taken into consideration. In cases of urgent
operations, when the patient was not prepared for it, his stomach is emptied from
its contents by suction drainage through a tube. The latter must be left in the
stomach till the end of the operation. Premedication is achieved by an intravenous
injection of 0.5 - 0.8 ml of an atropine solution and 1.5 -2 ml of a 1 %. promedole
solution. Induction of the anaesthesia is carried out with pentothal and hexenal.
Anaesthesia is produced with nitrous oxide and oxygen, adding ether in the
beginning and utilising promedole injections further. Muscle relaxants are used
with precaution, particularly in intestinal obstruction, preserving natural respiration
if possible. In shock nitrous oxide anaesthesia is admistered as early as possible
and promedole is injected. Measures are taken to arrest the haemorrhage and
relieve the patient from the state of shock. This is achieved by transfusions of
blood and its substitutes, infusion of antishock solutions, and by performing a
vagosympathetic paranephric circular and other types of block. The patient must be
warmly covered. I t is preferable to use a I %. pentothal or hexenal solution for the
induction of anaesthesia. This is followed by administering anaesthesia with a
mixture of nitrous oxide and oxygen in a ratio of 2 : 1, a small amount of ether
being added. Patients with bronchial asthma are given diprozine for premedication.
The use of cyclopropane is avoided in such cases and pentothal and hexenal are
administered only in minimum doses. Among the relaxants it is best to use ditiline.
Bearing in mind that in aged individuals all functions of internal organs are
diminished, the elimination of anaesthetic agents from the body is retarded, and
disturbances of respiration and blood circulation may be present, elderly patients
are protected from deficiency of oxygen flow, and relaxants are administered with
precautions without excluding natural respiration completely, if possible. In
children the premedication is given in doses corresponding to the age of the child.
The latter is brought to the operating room in a somnolent condition and is not tied
to the table until anaesthesia is produced. Pentothal is introduced per rectum in the
form of a 3 % solution, 20 minutes before the administration of anaesthesia It is
given in a dose of 0.04 g per 1 kg of body weight. Anaesthesia is produced with
cyclopropane, fluothane, or nitrous oxide small amount of ether being added. For
endotracheal anaesthesia children are intubated under ether anaesthesia. Operations
on the face and head arc performed under intravenous or endotracheal anaesthesia,
the tube being inserted through the mouth or nose. In neurosurgical intracranial
operation excitation is avoided. Morphine is not ideal. Anaesthesia is produced
with nitrous oxide and oxygen and deepened with fluothane and intravenous
injections of promedolc. Natural respiration is not completely arrested. In
intrathoracic operations endotracheal anaesthesia with controlled respiration is
used. Measures must be taken that the lungs expand completely before the pleura is
sutured. Patients with heart diseases are given special treatment to compensate the
condition. If possible, patients should not be operated in ten months following
myocardial infarction. Cardiacs are injected during the preoperative period
(camphor, cordiamine, and strophanthin intravenously). Before administering
anaesthesia patients are given oxygen to breath for 3 - 5 minutes. Then pentothal or
hexenal solution is injected slowly and with precaution. Anaesthesia is
administered with nitrous oxide and oxygen small amounts of ether are added, and
relaxants are used. Not infrequently hypothermia is employed in operations on the
heart. The blood temperature is lowered to 30 - 28°C. Open heart surgery utilises
an apparatus for extra corporeal circulation and controlled ventilation. In intraabdominal operations pentothal or hexenal is used for the induction of anaesthesia,
and anaesthesia is conducted by endotracheal introduction of nitrous oxide and
oxygen, or with ether-oxygen and muscle relaxants. The muscle tension must be
lessened throughout the entire operation, until the peritoneum is sutured.
Anaesthesia is deepened by administering promedole or by applying additionally
local anaesthesia of the mesenteries. Ambulatory operations are performed under
local anaesthesia or by producing analgesia with nitrous oxide and fluothane added
1 - 1.5 %. by volume. This method utilises special apparatus.
STUDENTS’ INDEPENDENT STUDY PROGRAM
I.
Objectives for Students’ Independent Studies
You should prepare for the practical class using the existing textbooks and
lectures. Special attention should be paid to the following:
1. Rendering an acute management by the surgical patient on pre-admission
stage.
2. Realization of reanimation actions by the surgical patient on pre-admission
stage.
II.
Tests and Assignments for Self – assessment
Multiple Choices.
Choose the correct answer/statement:
1. What breathing contour is used if patient inhales from the bottle and exhales
to the atmosphere?
1. Opened;
2. Semi opened ;
3. Closed ;
4. Semi closed;
2. In what stage of ether narcosis the operation can be performed?
1. Narcotic dream;
2. Analgesia;
3. Excitation;
4. Avakening;
3. Who demonstrated general narcosis?
1. William Thomas Morton;
2. Harry Wels;
3. Y. Chistovych;
4. James Young Simpson;
4. Acute hypercapnia is:
1. Accumulation СО2 in the blood of patient;
2. Accumulation СО2 in lungs of patient;
3. Accumulation СО2 in blood and lungs of patient;
4. Accumulation СО2 in tissues of patient;
5. Moment from which the cardio-pulmonary resuscitation begins:
1. Providing the upper respiratory ways passability;
2. Connection of electrocardiologic monitor;
3. Artificial ventilation of lungs by mouth-to-mouth method;
4. Preparing of the system for intravenous infusions;
5. Artificial ventilation of lungs with Ambu sac;
Real-life situations to be solved:
6. Patient 1 minute ago passed to a condition characterized by decrease of
central nervous system, breath, heart activity and absence of obvious
indicators of life. What happened?
1. Collapse;
2. Unconsciousness:
3. Clinical death;
4. Agony;
5. Pre-agony;
7. In patient that is in the state of the clinical death methods of cardiopulmonary resuscitation are ineffective. Was decided to perform the
defibrillation of the heart. To what position the switch of doses has to be put
in performing of defibrilation?
1. "1"
2. "2"
3. "3"
4. "4"
5. "0"
III.
Answers to the Self-Assessment:
1.
– A.
2.
– A.
IV.
3.
– A.
4.
– A.
5.
– A.
6.
– Clinical death.
7.
– "3".
References:
Essential reading:
1. Gostishchev V.K. General surgery /The manual. – M.: GEOTAR-MED,
2003. – 220p.
2. Lectures prof. B.I. Dmitriev from Odessa State Medical University.
3. Surgery: Text-book for English medium medical students / S.I.
Shevchenko, O.A. Tonkoglas, I.M. Lodyana, R.S. Shevchenko. –
Kharkiv: KSMU, 2001. – 344p.
4. Kushnir R. Ya. General surgery /Lectures.- Ternopil, Ukrmedknyha,
2005.- 308 p.
5. Butyrsky A. General surgery /The manual.- Simpheropol: publishers
CGMU, 2004.- 478 p.
Further reading:
1. Oxford handbook of clinical surgery / Edited by G.R. Mc Latchie, D.J.
Leaper, 2002.- 930 p.
2. Polskaya L.V. Nursing procedures in therapeutic practice.- Simpheropol,
Universum, 2004.- 192 p.
3. Clinical Nursing Skills and Techniques: basic, intermediate and
advanced. The C.V. Mosby Company, 1986.- 1296 p.
V.

Students’ Practical Activities:
9.00 - 12.00
 Work 1. Acquaintance with principles reanimation actions in surgical
patients.Definitions of indications and contraindications to the general
anesthesia.
VI.
Seminar Discussion Of Theoretical Questions And Practical Work:
VII. The initial level of knowledge and skills is checked by the decision of
situational problems (tasks) from each theme, answers to tests such as
"Step", constructive questions etc.
Students must know:
 Indications for performing general anesthesia;
 Classification of inhalation narcose's stages;
 Mechanisms of narcosis;
 Characteristics of stage of analgesia;

Characteristics of eyeballs' movements;
 Characteristics of corneal reflex's level;
 Characteristics of pupil dilatation level;
 Characteristics of biaphragmal breath level;
 Classification of inhalation narcosis complications;
 Sudden heart stop: reasons, clinics and treatment;
 Heart beat disorders: reasons, clinics and treatment;
 Embolism: reasons, clinics and treatment;
 Edema of lungs: reasons, clinics and treatment;
 Acute hypoxia: reasons, clinics and treatment;
 Hypercapnia: reasons, clinics and treatment;
 Gastro-intestinal tract organs' complications in postoperative period;
 History of local anesthesia;
 Classification of local anesthesia;
 Classification of local anesthetics;
 Technical aspects of local anesthesia;
 Classification of blockades;
 Classification of general status of surgical patient;
 Signs of clinical death;
 Correct conditions of performing indirect heart massage and artificial
ventilation;
 Types of heart massage and artificial ventilation;
 Meaning of intra-cordial punction;
 Classification of blood substitutes and their employment in the intensive
care;
 Equipment of wards in the intensive care unit.
Students should be able to:
 To determine the method of anesthesia in patient;

Evaluate the condition of patient for the adequate anesthesia;
 To prevent complications during general anesthesia;
 To provide the first aid in early postoperative period complications
development;
 To diagnose critical status of patient, clinical death;
 To perform indirect heart massage;
 To perform artificial ventilation "mouth-to-mouth", "mouth-to-nose";
 To determine location of intra-cordial punction;
 To determine the necessary soluble preparations for the intensive care.