Download Theory: I. Vital signs A. Pulse B. Blood pressure

Theory:
I.
Vital signs
A. Pulse
B. Blood pressure (BP)
C. Respiratory rate (RR)
D. Temperature
E. Saturation
These signs may be observed, measured, and monitored
to assess an individual's level of physical functioning.
Five types of blood vessels.
The pulse is a wavy movement of the arterial walls, which is generated due to
pumping function of the heart.
SIt is measured in beats per minute (BPM) .
Vital Signs: Pulse & Heart Rate
Basic Heart Anatomy
The Heart’s Location within the Thoracic Cavity
- The heart is a hollow, muscular, cone-shaped organ
o General location
a. Positioned in the mediastinum
b. within the pericardial cavity
c. between the pleural cavities
o enclosed by the pericardium
a. function –anchors & protects the heart
-
Esophagus and trachea are posterior to the heart
The Heart’s Internal Structure
- 4 chambers, or compartments
o Two superior chambers, or atria
o Two inferior chambers, or ventricles
o To prevent mixing of blood between chambers-- interatrial septum
and interventricular septum

Ventricular walls are thicker than atrial walls because they
are responsible for pumping blood into the systemic and
pulmonary circulations
o Right atrium
 Receives deoxygenated blood from the body from three
vessels
1. Superior vena cava
2. Inferior vena cava
3. Coronary sinus

From the right atrium, blood goes to the right ventricle
o Right ventricle
 Pumps deoxygenated blood into the pulmonary trunk
o Left atrium
 receives oxygenated blood via the pulmonary veins m
o Left ventricle
 Pumps oxygenated blood into the aorta

-
Left ventricular walls are thicker than right ventricular walls
because they need to contract with more force in order to
send blood throughout the systemic circulation
The systemic circulation supplies the tissues and organs of the body with
oxygenated blood
o the newly deoxygenated blood returns to the right atrium by the
superior vena cava, inferior vena cava, and coronary sinus
Your Beating Heart
The Heart at a Microscopic Level
- 2 functional units (syncytia):
o the atrial syncytium
o the ventricular syncytium
o Atria contract, then ventricles contract, then the heart relaxes
-
Two types of cells in the heart wall
o Contracting cells
o Cells that generate an electrical signal

Form the cardiac conduction system:
 Occurs in each heartbeat
The Cardiac Conduction System
-
Starts at the sinoatrial node (SA node)
o Location:
-
o Part of the cardiac conduction system that generates an electrical
signal most rapidly
o Spreads signal over entire atrial syncytium causing atrial
contraction
Signal spreads to the atrioventricular node (AV node)
-
Signal passes through the atrioventricular bundle (AV bundle)
-
Signal arrives in the interventricular septum
o Passes through two bundle branches (right and left)
-
At apex, the fibers branch extensively, forming Purkinje fibers
-
Electrocardiograms (ECGs) assess the cardiac conduction system
o Determine if electrical activity of the heart is working properly
Heart Valves, Part 1
-
Heart valves ensure that blood flows in one direction through the heart
o Composed of dense, fibrous connective tissue
o covered in endocardium-
-
Heart has 4 valves- organized as two pairs
o Atrioventricular valves (AV valves)

Location:

tricuspid valve

mitral valve:

Close when ventricles contract and the pressure in the
ventricles exceeds pressure in the atria


chordae tendinae:

papillary muscles contract along with ventricles,
creating tension in the chordae tendinae, preventing
the free edges of the valves from swinging upward
into the atria
Open after ventricular relaxation, when atrial pressure exceeds
ventricular pressure
o Semilunar valves (SL valves)
Heart Valves, Part 2
- Blood passes from right ventricle to the pulmonary trunk and from the left
ventricle into the aorta
o Semilunar valves:
 pulmonic valve

aortic valve

When closed, the cusps fall into the center of the pulmonary
trunk and aorta to prevent backflow of blood from the vessel
into the ventricle
When the ventricles contract, pressure in them increaseswhen ventricular pressure exceeds pressure in the aorta and
pulmonary trunk, the semilunar valves open
When the ventricles relax, pressure drops- when the
ventricular pressure falls below the pressure in the aorta and
pulmonary trunk, the semilunar valves close


Movement of valves during the cardiac cycle
-
When the heart is relaxed
o the semilunar valves are closed and the AV valves are open

blood is coming back to the right atrium through the
superior vena cava, inferior vena cava and coronary sinus

On the left side, blood is returning to the heart from the
pulmonary veins from the lungs
-
Atria contract
o Pressure in atria increases
-
Atria relax, ventricles contract
o Pressure in ventricles exceeds pressure in atria
o Pressure continues to climb as ventricles continue to contract ->
ventricular pressure exceeds pressure in aorta and pulmonary trunk
-
Ventricles stop contracting, start to relax
-
Cycle repeats
When valves close, they cause vibrations to occur in the blood that’s
passing through the heart
o Vibrations are carried to the body’s surface and can be heard with a
stethoscope
o sound one:
o sound two:
Assessing Heart Rate Demo
- Auscultation:
-
The heart is positioned deep to the sternum, slightly to the left of the
midline in the chest cavity
o the apex:
 Location:

Orientation:

-
Feeling the heart rate, assesses the number of beats per minute
Auscultation allows assessment of heart rate as well as heart sounds
o Heart sounds include sound one and sound two, usually called S1
an S2
 S1

-
point of maximal impulse- the most accurate place to check
heart rate
S2
Physicians often auscultate in multiple locations to assess heart sounds
related to the specific valves
o aortic valve:
o pulmonic valve:
o tricuspid valve:
o mitral valve:
-
If a valve does not close all of the way, it will make a swishing sound
If a valve does not open all of the way, it will make a clicking sound
The Cardiac Cycle, Part 1
Electrical Changes During the Cardiac Cycle
- Conduction system:
o Starts at the SA node
 Excitation of the atria creates the P-wave on an ECG
o Signal sent to the AV node
 Delayed for 1/10th of a second—
o Passed to AV bundle
 The only electrical connection between the atrial syncytium
and ventricular syncytium
o Excitation of the ventricles creates the QRS complex on an ECG
o Heart relaxes, ventricles repolarize
 Creates the T wave on the ECG
-
These electrical signals create changes in the contracting cells, triggering
muscle contraction
Video 1.4b: The Cardiac Cycle, Part 2
Pressure Changes During the Cardiac Cycle
- Pressure changes in the heart cause the valves to open and close, to
prevent backflow of blood
o The P wave on an ECG is followed closely by an increase in atrial
pressure
 atrial contraction, atrial systole
After atrial systole, the atria contract and pressure remains
low
o The QRS complex on an ECG is followed almost immediately by
an increase in ventricular pressure
 The period of ventricular contraction is called ventricular
systole


When ventricular pressure exceeds aortic pressure, the
semilunar valves open

Once this pressure peaks, the ventricles stop
contracting
o Pressure in ventricles falls below the pressure in
the aorta and pulmonary trunk

The ventricles continue to relax and ventricular
pressure continues to fall
o When this pressure falls below atrial pressure,
the AV valves open
o The period when the ventricles are relaxed is
called ventricular diastole –during this phase,
ventricles fill with blood
Ventricular Volume During the Cardiac Cycle
-
Ventricular volume is fairly high during relaxation, or diastole
-
During atrial systole- a little more blood is pushed into the ventricles, so
the volume increases slightly
-
Ventricles contract, pressure increases and volume decreases
o Blood is being ejected to the aorta and pulmonary trunk
o AV valves open and ventricular volume begins to increase again
Heart Sounds During the Cardiac Cycle
o Heart sound one indicates the start of ventricular systole
o Heart sound two indicates start of ventricular diastole
Assessing Pulse Demo
-
Heart rate:
-
Pulse:
o We assess pulse in elastic arteries, which can distend and retract
o Pulse and heart rate are typically the same in a person with healthy
cardiovascular function, but could be different if someone has poor
peripheral circulation or arterial disease
Locations to assess pulse:
- carotid artery
-
brachial artery (at the antecubital fossa)
-
radial artery
-
femoral artery
-
dorsalis pedis
-
posterior tibial
Cardiac Output
- Need to keep blood circulating through the body to supply the cells with
oxygen and nutrients and to carry away metabolic waste products
- Cardiac Output (CO) = the volume of blood ejected per minute
o Influenced by heart rate (HR) and stroke volume (SV)
o CO = HR x SV
-
Stroke volume: the volume of blood ejected during a single heartbeat
o End diastolic volume (EDV):
o End systolic volume (ESV):
o Stroke volume = EDV - ESV
-
Cardiac output can be increased or decreased to meet the needs of the
body
-
The autonomic nervous system plays a role in regulating cardiac output
o Two branches: parasympathetic and sympathetic
 sympathetic division:

in the heart, the sympathetic nervous system
innervates SA node, AV node and the contractile
cells of the myocardium

when activated, causes the SA node to depolarize
more quickly and can shorten the delay at the AV
node
o tachycardia = HR > 100 bpm


sympathetic activation also causes contractile cells of
myocardium to contract more forcefully -> leads to
increased stroke volume
parasympathetic division:


in the heart, the parasympathetic nervous system
innervates the SA node & the AV node
parasympathetic nervous system slows the SA node’s
rate of self-excitation
o parasympathetic signals are carried to the SA
node by the vagus nerve
o bradycardia = HR < 60 bpm
: Introduction to the Blood Vessels
Anatomy of the blood vessels
-
Five types of blood vessels:
o arteries
o arterioles
o capillaries – site of gas exchange
o venules
o veins
-
Two circulations
o Systemic circulation:




arteries carry blood to capillaries
in the capillary beds, oxygen (O2)leaves blood and moves to
tissues and carbon dioxide (CO2) moves from the tissues to
the blood
deoxygenated blood is then brought back to the right side of
the heart through systemic veins
aorta carries blood into the systemic circulation

aorta branches into smaller arteries

branching continues until vessels are small enough
that they are called arterioles

small arterioles carry blood to capillaries

capillaries converge to form venules

venules converge and form veins
o Pulmonary circulation:

pulmonary trunk carries deoxygenated blood into the
pulmonary circulation



it branches into R. & L. pulmonary arteries, which
carry blood to the R. & L. lungs, respectively
gas exchange occurs in pulmonary capillaries
pulmonary veins carry oxygenated blood back to the left
side of the heart
Blood Vessel Structure
All blood vessels except the capillaries have walls consisting of 3 layers
-
tunica intima
o innermost layer is called endothelium –it is continuous with
endocardium of the heart
o thin, smooth tissue – low friction for blood flow
o directly surrounds the lumen:
o endothelium is the only tissue layer in capillaries
-
tunica media
o contains many elastic and smooth muscle fibers
 elastic fibers - able to distend and retract
 smooth muscle is arranged in concentric layers around the
wall of the vessel


when the smooth muscle contracts, it causes the
vessel diameter to decrease in size –this is called
vasoconstriction
conversely, when the smooth muscle relaxes, the
vessel diameter increases –this is called vasodilation

innervated by the sympathetic nervous system
o even at rest, the sympathetic nervous system
is sending signals to the vascular smooth
muscle, causing a baseline level of
vasoconstriction
o higher level of sympathetic outflow, cause
greater stimulation of the smooth muscle
which can cause greater amount of
vasoconstriction
-
tunica externa
o made of a layer of connective tissue
o anchors the blood vessel in place and helps protect the outside of
the vessel
Specific Type of Blood Vessels- Structure and Function
-
3 general types of arteries:
o elastic arteries
 closest to heart
 tunica media contains relatively more elastic fibers
 these large arteries have to be able to distend during
ventricular systole to compensate for the surge of blood
 then, the vessels retract during diastole, maintaining
pressure which allows for a continuous flow of blood

atherosclerosis
o muscular arteries
 tunica media contains more smooth muscle

because there is more smooth muscle in the vessel walls,
these vessels have a greater ability to vasoconstrict or
vasodilate,, which allows them to channel blood to different
organs or regions of the body
o arterioles
 large amount of smooth muscle in tunica media
 very responsive to signals from the sympathetic
nervous system in terms of vasoconstricting or
vasodilating

-
these vessels have a big impact on vascular resistance
veins
o venous walls are always thinner than an arterial wall that is the
same distance away from the heart
o thin, collapsible walls which distend and collapse easily
o veins have relatively large lumen diameters
o due to the structure of veins, venous pressure is low
Video 2.3: Blood Circulation
Blood Circulation
- heart beats intermittently yet blood flows continuously
- blood flow = volume of blood that moves through a level of the vascular
system per minute
o blood flow is equal to cardiac output (CO)
o blood flow is fairly constant under resting conditions
-
blood pressure = force exerted per unit of surface area against the inner
walls of a blood vessel
o unit of measurement is millimeters of mercury (mmHg)
o blood flows from region of high pressure to region of low pressure
-
resistance = anything that opposes, or impedes, blood flow
o most resistance is in the systemic circulation, away from heart –
called peripheral resistance
o influenced by several factors:
 vessel diameter



#1 factor responsible for changes in vascular
resistance
arterioles are most responsible for changes in
peripheral resistance
blood viscosity- thickness or thinness of the blood

is fairly constant in healthy people
o anemia
o polycythemia

vessel length

pulmonary vs. systemic circulation-
Video 2.4a: Maintaining Blood Flow
-
pressure gradient –difference in pressure from one part of the vascular
system to another
o blood flows down its pressure gradient
-
pressure across the systemic circulation
o systolic pressure (SBP)

generated by ventricular contraction

= the highest pressure achieved in the large arteries
o diastolic pressure (DBP)



achieved during ventricular relaxation
= the lowest pressure in the large arteries, achieved at the
end of ventricular diastole
during diastole, elastic arteries retract to maintain pressure –
diastolic pressure is lower than systolic pressure
o mean arterial pressure (MAP)




-
highest MAP occurs in large arteries
lower in smaller arteries due to increased resistance
decreases across the capillary beds
lowest in the large veins close to the heart
MAP continues to drop in the veins- several features help to maintain
blood flow through the veins even though pressure is low
o venous valves --prevent backward flow of blood
o skeletal muscles
 muscles bulge when contracted -- pushes on veins to send
blood to heart
 then, during muscular relaxation, venous valves prevent
backflow
o pressure changes in the thoracic cavity during breathing –lower
thoracic cavity pressure during inhalation helps return blood to the
heart
Assessing Blood Pressure
To take a blood pressure:
- gather necessary equipment:
o inflatable cuff attached to a sphygmomanometer
 make sure the cuff is the correct size –if cuff size is wrong,
the BP readings will not be accurate
o stethoscope
-
apply the cuff-
o line up artery marker with brachial artery
o cuff bottom should be in crook of the elbow (i.e., the antecubital
fossa)
-
taking the pressure
o ideally, take the reading in the left arm and support the arm at the
same level of the heart to get the most accurate reading
o inflate the pump – this will cause cuff to inflate, occluding arteries
under the cuff



arteries collapse, preventing blood flow
release gauge to deflate cuff
listen to brachial artery – will be quiet until blood flow is no
longer occluded
 Korotkoff sounds

note first sound and last sound (the 5th)
 systolic pressure –corresponds to the first Korotkoff
sound


diastolic pressure –sound of turbulent flow stops
because blood is flowing smoothly through the artery
again
blood pressure reading of 110 over 62 (110/62) –SBP
is top number, DBP is bottom number
Blood Pressure Regulation
Normal and abnormal blood pressure
- In healthy adults, systolic blood pressure should be no higher than 120
mmHg and diastolic should be less than 80 mmHg
- low blood pressure (hypotension)
o typically not a problem unless it interferes with the ability to carry
blood to the tissues
-
hypertension---i.e., high blood pressure
o can cause damage to blood vessel endothelium
 over time, leads to narrowing of lumen and blood flow
restriction
o damage to heart
 increased workload

structural changes
o one can have hypertension and not experience symptoms –because
untreated hypertension can damage the cardiovascular system, it is
important to have BP assessed regularly and treat hypertension
Factors affecting mean arterial pressure
- cardiac output
-
resistance
o arterioles create the most vascular resistance
o cardiovascular regulatory centers—in brainstem
-

receive input from baroreceptors –these are sensors in blood
vessel walls that detect the level of stretch in the blood vessel
walls

regulate pressure by changing vessel diameter and cardiac
output
blood volume
o normally is fairly constant
o long term mechanisms involving hormonal regulation and kidney
function can change blood volume which then lead to changes in
blood pressure
Introduction to Thermoregulation
-
metabolic rate: measure of all of the chemical reactions going on in the
body at a given time
o certain organs have continuous rate of metabolism that contributes
significantly to establishing our resting metabolic rate --e.g., the
heart, brain, liver, kidneys
o body core –the internal region of body where we normally
maintain a fairly constant temperature
o heat is released with an increase in metabolic rate because cells are
not 100% efficient –increased metabolism, as occurs during
exercise, creates more heat
o core body temperature
normal range: 35.8°C-38.2°C

normal core temperatures vary between individuals and
throughout the day
 lowest during

highest during-
important to maintain a normal temperature for optimal
enzyme activity-
o body shell

more temperature fluctuation occurs in the body shell
 based on atmospheric temperature and body’s
metabolic rate

blood – mechanism of heat transfer in body

-
picks up heat in body core > carries heat to less
metabolically active parts of body
types of heat transfer:
o conduction –heat transfer between 2 objects in direct content
o radiation –transfer of heat in the form of infrared waves
o convection –heat loss that occurs because a warm fluid (which
could be air or liquid) rises away from the body surface and is
replaced by a cooler fluid
 body heat will transfer to the cold fluid, which will then rise
away from the body surface and be replaced by cooler fluid
 the cooler fluid will warm (due to heat transfer from the
body) –and then it will rise away from the body surface
 the greater the temperature gradient between the body and
the cool fluid that replaces the warm fluid, the greater will
be the heat loss

wind chill
o evaporation
 heat is required to vaporize water (called the “heat of
vaporization”)



-
it is not sweating per se that makes us feel cooler –it is
the evaporation of sweat that cools us
when sweat evaporates, it is body heat that vaporizes
the water in sweat
heat index
heat loss from the body can be sensible or insensible:
o sensible heat loss
example: sweating
o insensible heat loss
example: evaporation that occurs as air moves past the
airway surfaces during inhalation
Maintaining Body Temperature
Reflex arc:
-
all reflex arcs begin with a sensory receptor –the temperature sensors of
the body are called thermoreceptors
o peripheral thermoreceptors


sensitive to hot and cold
peripheral thermoreceptors provide the information which
helps us cope with environmental temperature changes

body has high water content which creates thermal inertia –
peripheral thermoreceptors make the brain aware of changes
in environmental temperature so that adjustments can be
made to maintain core temperature
o central thermoreceptors
-
neurons carry the sensory input to the hypothalamus, which is the control
center for body temperature regulation
o temperature control center is located in the preoptic nucleus of the
hypothalamus
-
motor effects allow us to maintain our temperature
o temperature homeostasis –state of dynamic equilibrium in which
we maintain our body core temperature within the normal range
(35.8°C-38.2°C)
o decreased body temperature –when body temperature falls below
the hypothalamic set point it causes:

vasoconstriction of subcutaneous blood vessels

shivering the slight shaking or shuddering that we call
“shivering” is due to rapid involuntary muscle
contractions
 remember: about 60% of the energy stored in the
molecular bonds of fuel molecules is released as heat
 thus, as skeletal muscles generate ATP to fuel
shivering, they also generate a lot of heat

hormonal secretion
 in prolonged cold, hormones can stimulate
metabolism & help to maintain a normal body
temperature
o increased body temperature – body/blood is warmer than the
hypothalamic set point

vasodilation of subcutaneous blood vessels


increases heat loss via radiation (and possibly
convection)
sweating
o negative feedback is built into the temperature regulating system
Hypothermia & Hyperthermia
-
hypothermia –condition in which the body core temperature falls below
the normal range
o normal physiological mechanisms to warm body (constriction of
subcutaneous blood vessels, shivering) are not enough to raise body
temperature back to the normal range
o manifestations decreased heart rate
 decreased respiration rate
 decreased blood pressure
 brain functions will also begin to fail if the hypothermia
become severe enough and/or prolonged
o interventions-
-
hyperthermia:
o varies in severity


heat exhaustion

blood cannot circulate effectively due to blood
volume loss from excessive sweating

conflicting signals

can occur after prolonged exercise in heat

manifestations dizziness, headache, noise discomfort in
the stomach

interventions: cool them down, hydrate them, in a
shade, rest not to cerate more heat
heat stroke –condition is more severe than heat exhaustion

positive feedback cycle created that generates heat
loss mechanisms that worsen the condition

manifestations:
o hot, dry skin
o organs shut down (i.e., organ failure)

predisposing factors can put some people at higher
risk:
o older adults
o young children and neonates
o people with cardiovascular diseaseo pregnant womeno people who have impaired fluid regulation
capability (as in chronic kidney failure)-

interventions:
Fever
-
Fever:
o pyrogens –molecules released by the cells of the immune system
that have the ability to raise the hypothalamic set point
 released by cells of the immune system (mainly) and can
circulate in the blood
 when they arrive in the brain, they affect hypothalamic
function
 when hypothalamus set point is increased, the higher body
temperature of a fever is interpreted by the hypothalamus as
“normal”
o may feel cool despite high temperature
o a fever “breaks” when the pyrogens are removed from body and
hypothalamus returns to normal set point
o fever is not always a bad thing
Assessing Body Temperature Demo
-
Types of thermometerso oral

place probe of thermometer in sublingual pocket
close to sublingual artery – a deep artery, which
gives a more accurate measure of core body
temperature
o temporal

run probe over patient’s forehead –assesses temperature in
temporal artery, which also carries blood a short distance
from the core and gives a relatively accurate measure of core
temperature
o tympanic

placed in external auditory canal against tympanic
membrane (or ear drum)
 close to hypothalamus --thus, gives a fairly accurate
measure of core temperature
o axillary

measured in axilla (or armpit)
 it is difficult to get an accurate reading at this site, for
various reasons
o rectal


-
sensor probe is placed in rectum
requires practice and training for accurate readings
important to take a temperature when patient is healthy –then, are able to
compare future readings to this baseline temperature
Airway management:
1.
2.
3.
4.
Airway obstruction
Oxygen concentration in particular passive ventilation equipment.
Passive vs. active ventilation
Non instrumental airway patency manuvers
IV
p.o. to swallow
s.l. under a tongue
s.c. – subcutaneous, under the skin
i.m. – intramuscular, into a muscle
i.v. into a vein
i.a. intra-arterial- into an artery
Intravenous cannulation
a cannula is placed inside a vein to provide venous access.
Venous access allows sampling of blood as well as administration of fluids,
medications, parenteral nutrition, chemotherapy, and blood products.
In general, peripheral catheters are preferred when IV access is required for
shorter periods, when smaller gauge catheters suffice.
Peripheral access is generally safer, easier to obtain, and less painful than central
access.
There are few contraindications to the placement of peripheral venous catheters. Most
concern problems with cannulation at a specific site. The sole absolute
contraindication is when appropriate therapy can be provided by a less invasive
route (eg, orally).
Many sites can be used for peripheral intravenous (IV) access, and they vary in their
ease of cannulation and potential risks.
Site selection varies according to clinical circumstances, expected duration of
treatment, and the condition of the extremities.
•distal extremity sites should be used first,
•Larger veins are generally more easily cannulated and are preferable to smaller
veins in the same region.
•Veins of the upper extremity are preferred due to the increased risk of thrombosis
and thrombophlebitis with venous cannulation of the lower extremities.
Whenever possible, avoid using the dominant upper extremity.
Contraindications to the use of a particular extremity include the presence of an
arteriovenous fistula (catheter can alter venous blood flow or damage the fistula)
and a history of mastectomy or lymph node dissection (catheter can exacerbate
impaired lymphatic drainage). Venous catheter placement should be avoided at a site
that may interfere with an anticipated procedure (eg, an injured extremity that
requires surgery).
http://www.uptodate.com/contents/peripheral-venous-access-inadults/abstract/5
Veins that are firm to palpation may be sclerosed (eg, from IV drug abuse) and should
be avoided as should veins with evidence of phlebitis or thrombosis.
Venous puncture at sites where catheter placement was recently attempted should also
be avoided, especially if a hematoma formed (ie, vein was "blown") following the
previous attempt.
Placement of an IV through infected tissue is not advised due to the risk of
introducing a systemic infection. In addition, peripheral IV catheters should not be
placed through burned tissue or in extremities with massive edema.
The veins of the dorsum of the hand are often the most accessible sites for
peripheral cannulation. As an example, the dorsal metacarpal veins are usually
visible and palpable and make good sites for IV catheter placement. These veins
merge into the dorsal venous network (or arch) and then form the cephalic vein,
which runs along the lateral distal forearm.
The cephalic vein is usually visible and palpable and therefore another good site for
cannulation. The volar forearm also contains several veins that can be cannulated,
including the median antebrachial veins.
The antecubital fossa, though not a primary choice for nonemergent IV access,
contains several accessible veins, including the cephalic, median cubital, and basilic.
These veins are usually large and easily cannulated and provide a useful option when
emergent IV access is needed.
In addition to the arm, leg and neck veins can be used to obtain peripheral IV access.
The external jugular vein, which drains into the subclavian, is a large vein in the
neck that is easily cannulated, even in patients with severe volume depletion or
otherwise poor extremity access. Placing the patient's bed in a head-down (ie,
Trendelenburg) position.
Veins of the leg, including the greater saphenous vein at the level of the medial
malleolus and the dorsal metatarsal veins on the dorsum of the foot, are often
accessible.
However, lower extremity sites should be used only if veins in the arm cannot be
cannulated.
Placing the anticipated cannulation site below the level of the heart uses gravity to
reduce venous return, which causes blood to pool and veins to distend.
Lightly tapping or gently stroking the vein along its length in a proximal to distal
direction causes venous distension.
Another simple, effective way to dilate veins consists of having the patient alternately
clench and relax their fist.
Nitroglycerin ointment applied to the venipuncture site and left for two minutes
causes venous dilation and does not appear to cause deleterious changes in blood
pressure, even in hypotensive patients.
Elevating skin temperatures to 39 to 42°C at the cannulation site causes venous
dilation. This can be accomplished by placing the site in warm water or by applying a
warm compress (eg, warm moist cloths, warming packs, heated carbon fiber mitts).
Proximal compression, most often using a thin rubber tourniquet placed 5 to 10 cm
proximal to the anticipated venipuncture site, impedes venous return and enhances
venous dilation.
Peripheral IV catheters placed for intermittent therapy (INT) require occasional
flushing to keep them patent. This is not a concern when catheters are used for
continuous infusions.
No studies address the issue of how best to flush peripheral catheters with saline, but
common practice is to use 2 to 10 mL of isotonic saline after any IV medication is
given or every 4 to 12 hours.
Intrumental airway management:
OPA
NPA
LMA
LT
I-GEL
OPA
-Maintaining airway patency in case of unconscious patient.
-Artificial ventilation.
-It is also used when intubation is performed.
OPA's should not be used on any patient that has an active gag reflex.
The OPA should also not used in patients with known or suspected palate fractures
The correct size will vary with each patient.
1. To size the OPA, it is measured against the distance from the corner of the patient's
mouth to the patient's earlobe.
Or
2. Measuring the distance from the incisors to the angle of the jaw.
Insertion:
Insert OPA when a patient is on the back or on the side
After openning patient’s mouth, insert OPA convexity facing down
Halfway along the tongue(at the junction between the soft and hard palate) rotate
through 180°
Perform this operation with caution, being careful not to push the tongue;
After regaining consciousness, OPA need to be dislodged to avoid gagging, vomiting
NPA
Patient not deeply unconscious prefer the NPA;
It can save patient's life in the case of lockjaw or craniofacial injuries;
Sizes for adults 6 i 7 mm;
Laryngeal mask airway
The essence of the action is covering of the laryngeal aperture using mask with a
small elastic cuff combined with a broad cross-section of the tube, ending with a
standard diameter connector. This connector is used to connect the systems for
anesthesia. Laryngeal mask ensures good airways patency, without causing
complications associated with intubation.
They depend on the patient's weight.
LMA advanteges:
simplicity of the technique;
minor complications;
allows to avoid intubation;
no need for aneastetics ;
possible to use in case of peadiatric patient;
no latex.
Indication:
Surgeries where intubation is not required;
May serve as an interim measure in the unconscious patient, when intubation has
failed
Oxygenation in sudden situation
Contraindications:
vWill not be tolerated in patients with high level of laryngeal reflexes
(full stomach, bowel obstruction, a large degree of obesity, pregnancy);
vobstruction in the larynx or trachea area;
vvery limited mouth opening(<1,5 cm);
vthe use of high pressure breathing during ventilation
I-gel:
Easy insertion
Minimal risk of tissue compression
Stability after insertion
Latex free, single use
Reduced risk of aspiration:
https://www.youtube.com/watch?v=ao-Sb_OulE8