Download Advanced Pain Control and Sedation

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Advanced Pain Control and Sedation.
This information builds upon basic concepts in sedation and introduces more advanced techniques in intravenous sedation, pain control,
and local anesthesia. Knowledge gained from this information will assist the clinician in choosing the appropriate technique to better
manage his patients; however, this module is meant to serve only as an introduction to more advanced techniques.
http://ccnmtl.columbia.edu/projects/aegd/mod01_intro.html
Clinical Assessment and Guidelines
Definitions: JCAHO Definitions of Sedation Levels
Type
Definition

Minimal Sedation
(Anxiolytic)
A drug-induced state during which patients respond
normally to verbal commands. Although cognitive
function and coordination may be impaired,
ventilatory and cardiovascular functions are
unaffected.
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A drug-induced depression of consciousness during
which patients respond purposefully to verbal
Moderate
commands, either alone or accompanied by light
Sedation/Analgesia
tactile stimulation. No interventions are required to
"Conscious Sedation" maintain a patent airway, and spontaneous
ventilation is adequate. Cardiovascular function is
usually maintained.
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Signs
Normal response to verbal
stimulation
Airway unaffected
Spontaneous ventilation
unaffected
Cardiovascular function
unaffected
Notes
Purposeful response to verbal
Reflex withdrawal from a
or tactile stimulation
painful stimulus is NOT
No airway intervention
considered a purposeful
required
response. Practitioners
Spontaneous ventilation
involved with moderate
adequate
sedation must be prepared
Cardiovascular function usually
to "rescue" from deep
maintained
sedation.
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Deep
Sedation/Analgesia
General Anesthesia
A drug-induced depression of consciousness during
which patients cannot be easily aroused but respond
purposefully following repeated or painful
stimulation. The ability to independently maintain
ventilatory function may be impaired. Patients may
require assistance in maintaining a patent airway,
and spontaneous ventilation may be inadequate.
Cardiovascular function is usually maintained.
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Purposeful response following
repeated or painful stimulation Reflex withdrawal from a
Airway intervention may be
painful stimulus is NOT
required
considered a purposeful
Spontaneous ventilation may response. Providers of deep
be inadequate
sedation/analgesia must be
Cardiovascular function usually prepared to "rescue" from
maintained
general anesthesia.
A drug-induced loss of consciousness during which
patients are not arousable, even by painful
stimulation. The ability to independently maintain
ventilatory function is often impaired. Patients often
require assistance in maintaining a patent airway,
and positive pressure ventilation may be required
because of depressed spontaneous ventilation or
drug-induced depression of neuromuscular function.
Cardiovascular function may be impaired.
Guidelines for Sedation
Sedation guidelines include the following:
1. It is important to perform a pre-procedure assessment. This assessment will provide a focused medical history and physical
examination, laboratory data in select patients may be, may be required. The ASA Physical Status of the patient will be
assigned (definitions of the ASA Physical Status will be described in a later part of this lecture).
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2. Informed consent must be obtained.
3. The patient, should fast prior to procedure.
4. The patient must be escorted home.
Preprocedure fasting applies to all patients undergoing moderate sedation. Adults and children older than 36 months should be NPO
for solids and non-clear liquids for six to eight hours prior to the procedure, however they may have clear liquids two hours before the
procedure. Patients at increased risk for aspiration, such as the obese, should be NPO for more than eight hours.
Patient Assessment
It is important to perform a history and do a focused physical exam to be sure that there aren't any medical risks that would predispose
the patient to a medical emergency during the actual procedure. It is also important to talk to the patient to get a feel for the patient's
psychological state. Be sure to assess the following:
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Can the patient tolerate the stresses of the procedure?
Are modifications to the treatment plan necessary based upon the patient's history and physical?
Is premedication with anxiolytics required just to get the patient into the office?
Risk Assessment
In order to answer these questions, a risk assessment is performed, which requires taking a medical history and performing a physical
examination.
Most of the information obtained in the medical history will be the basis for the risk assessment and it is important for the clinician to
spend time talking with the patient. Information gathered in the patient history includes:
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presence of systemic diseases
previous hospitalizations
previous surgeries
previous anesthetic events (how did the patient fare?)
allergies
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medications
patient's family history for illness
social history
drug or tobacco use
patient's dental history
how the patient fared during previous dental treatment.
During the physical examination a review of systems is conducted, in order to obtain information about specific organ systems. The
focused physical exam should include the following components:
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Test Results
Assessment of physical, mental and neurological status
Vital Signs
Airway Assessment
Lung Assessment
CNS and PNS Assessment
Physical Examination
A good history is merely confirmed by the physical examination. Begin with the basic vital signs including blood pressure, heart rate,
respiratory rate, and record the height and weight of the patient.
A complete pre-operative physical exam should also include a head and neck exam, cardiovascular exam and pulmonary exam. In
addition, it is also important to perform an airway exam, and that involves looking at the tongue, at the neck. During the airway exam,
use the following questions to help you determine if the patient is at risk for airway obstruction during sedation:
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What is the mandibular range of motion?
Are there tonsils present that might obstruct the airway?
When the patient opens his/her mouth and sticks out the tongue, can you see the uvula and the pharynx?
Is the patient obese?
Does the patient have a fat neck, a short neck, or a large tongue that would make ventilation difficult?
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During the history and physical examination, it is also important to ascertain the patient's anxiety level. Some symptoms of anxiety
include sweating, dilated pupils; the patient may also be very talkative, and/or may have an increased blood pressure and heart rate.
ASA Classification System
The ASA Classification system is used by anesthesiologists to classify patients according to their medical history. It is a graded scale
from one through five, with an E is added to indicate an emergency procedure.
P1 A normal healthy patient
P2 A patient with mild systemic disease
P3 A patient with severe systemic disease
P4 A patient with severe systemic disease that is a constant threat to life
P5 A moribund patient who is not expected to survive without the operation
P6 A declared brain-dead patient whose organs are being removed for donor purposes
For example, a healthy normal 18-year-old patient would be an ASA P1. If that patient was undergoing an emergency appendectomy,
then the classification would be 1E
Examples of an ASA 2 would be:
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a healthy pregnant female
any healthy patient over the age of 60
a healthy patient but one who is extremely phobic
someone with mild hypertension
a well-controlled Type II diabetic.
Examples of ASA 3 patients include:
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well-controlled Type I diabetic
has had a myocardial infarction more than six months ago
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has well-controlled chest pain
has COPD.
Examples of ASA 4 patients include:
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has shortness of breath at rest
has chest pain at rest
has had a myocardial infarction within the past six months
has uncontrolled hypertension
COPD patient requiring constant oxygen therapy
Patients classified as ASA 1 or 2 do not require any modifications to the sedative technique. An ASA 3 patient requires more caution;
modifications might be needed, such as lighter sedation or treatment in a hospital setting. An ASA 4 patient should only be treated in a
hospital dental facility, and should generally undergo emergency and palliative care only.
Special Cases to Consider
Cardiac Disease
Cardiac disease can be congenital, such as congenital valvular disease or it could be acquired, such as acquired valvular disease, with
rheumatic heart disease. Patients with coronary artery disease who may have angina pectoris or have a history of myocardial
infarction. Patients may also have congestive heart failure, and may have arrhythmias.
With patients with coronary artery disease, the goal is to decrease the oxygen requirements of the heart. Stress reduction is critical, and
the administration of supplemental oxygen is important. This is where conscious sedation can become very critical in whether or not a
patient can be treated, as benzodiazepines will increase sympathetic outflow. These patients may require shorter appointments as well.
Does the patient have a cardiac pacemaker? It is important to ascertain the need for stress reduction to minimize rhythm abnormalities
during treatment; it is also important to find out whether an implantable defibrillator has been installed.
It is important to ascertain the following:
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Date and type of cardiac surgeries, if any.
Has the patient had an M.I. before they had their cardiac surgery?
Patients pre and post-surgical symptoms and limitations.
Changes in patients symptoms following cardiac surgery.
Rheumatic Fever
Patients with a history of rheumatic fever may have had rheumatic heart disease and valvular disease. These patients may develop
congestive heart failure from their valvular disease and may have undergone a valve replacement. If the patient has had a valve
replacement, it is important to ascertain whether the patient is anticoagulated. In addition, it is always important to cover these patients
for SBE with appropriate antibiotics.
It is important to ascertain the following:
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Whether the patient anticoagulated.
If/when the patient had valve surgery.
What antibiotics are needed to cover the patient's heart.
Patient's with a CVA have other considerations. Hypoxemia and hypoxia places these patients at greater risk for a repeat CVA;
therefore a light sedation and inhalation technique, perhaps with nitrous oxide, is the best approach for these patients. Be very careful
when deciding to sedate a patient with a history of multiple TIAs, as such patients are at high risk of develop a CVA if they become
hypoxic in your chair.
Pulmonary Disease
There are two global categories of pulmonary disease: restrictive pulmonary disease, such as scoliosis, kyphosis and thoracic cage
deformities, and obstructive diseases, such as asthma and COPD. Asthma is a disease of obstruction of the lower airways. Patients are
at risk when a histamine is released, which might occur with the administration of certain narcotics and barbiturates. In patients with
significant asthma, it is important to avoid barbiturates and certain narcotics which can cause histamine release.
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Patients with COPD, generally with emphysema, have a decreased respiratory reserve. Many of these patients tend to be barrelchested, and they may come into your office on supplemental oxygen. These patients should be sedated carefully and very lightly,
because they are no longer breathing based upon their CO2 drive, but based upon their PA O2.
In patients with asthma, it is important to ascertain the frequency of the asthma, the severity of the asthma, and the causative factors.
Be sure to ask about:
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Medications the patient is currently taking.
Whether the patient has had multiple emergency room visits or has ever been intubated for the asthma. (If so, when?)
Whether the patient has been on systemic steroids for the asthma. (If so, when was the last steroid administration?)
Hypertension
Sedation can be very useful in lowering the blood pressure in the anxious patient. However, hypertensive patients are also at higher
risk for a hypertensive crisis, defined by a systolic rate within 250 mm hg and/or a diastolic rate within 130 millimeters; in case of a
hypertensive crisis should be transported to the local emergency room, and the patient's physician called.
It is important to ascertain the following:
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How well blood pressure is controlled.
Current medications.
Patient's baseline blood pressure.
Diabetes
Diabetics: how well controlled is the diabetes? Is the patient a Type I insulin dependant? Is the patient a Type II diabetic? Does the
patient have associated coronary artery disease? These are all important considerations in doing a risk assessment. Of course, there are
other diseases as well, such as thyroid disease, renal disease and liver disease, which are extremely important.
Renal Disease
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Renal disease for altered excretion of drugs that we administer and their metabolites. The liver, of course, is very important because
that is where metabolism occurs of most of these agents. Plasma proteins are manufactured in the liver, which bind these drugs in the
circulatory system, and, of course, patients with significant liver disease will also have coagulopothies. G.I. disease with altered
absorption is also important to be aware of.
Pregnancy
Teratogens during the first trimester, when the embryo is developing vasoconstrictors, may cause vasoconstriction of the placental
circulation. Nitrous oxide and oxygen are generally safe to use during the second trimester.
Clinical Procedure
Intraprocedural Management
Intraoperative management requires well-trained personnel, monitoring equipment and emergency equipment. With conscious
sedation, or moderate sedation, the sedation is directed by a qualified practitioner. A second qualified individual, competent to monitor
and observe and to intervene if necessary, should also be present in the room. There should also be a third individual to assist with the
procedure.
Monitoring
Monitoring of the patient is required. These include monitoring the patient's respiratory rate and patency of the airway. The patient's
vital signs, including heart rate, blood pressure, oxygen saturation and level of consciousness must also be continuously assessed. The
electrocardiogram may be required based upon the history and/or state regulation.
The first piece of equipment is a blood pressure cuff. Prior to starting any sedation, the patient's baseline blood pressure should be
obtained.
The pulse oximeter is used to monitor the resting oxygen saturation in a patient's red blood cells, and will also monitor the patient's
heart rate. The probe is placed on the patient's index finger, and readings are provided by the monitor. Again, a baseline measurement
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should be obtained prior to sedation. For more information on pulse oximetry visit
http://www.nda.ox.ac.uk/wfsa/html/u05/u05_003.htm
Finally, an electrocardiogram monitor, also referred to as an ECG or EKG monitor, is used to monitor the electrical activity of the
patient's heart. To obtain readings, remove the protective covering from the electrodes and place one on each of the patient's arms and
legs, and on his chest. Once all of the leads are in place, turn on the ECG monitor; for continuous monitoring of the patient's cardiac
rhythm, displayed on the ECG monitor screen.
The JCAHO's competency course on Sedation & Analgesia provides more information on Monitoring, including heart rate,
respirations, EKG, blood pressure and oxygenation at http://www.sedationtraining.com/Monitoring/default.asp View the section on
monitoring, and take the review quiz at the end to test your knowledge.
Placing an IV
Before you begin placing the IV, make sure that you have the following materials gathered and organized within reach:
1.
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3.
4.
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6.
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IV Fluid Bag
IV Tubing
Tourniquet
Angiocatheter (Consists of a needle with an overlying catheter)
Alcohol Swab
Gauze
Tape
Begin by connecting the IV tubing to the IV fluid bag and let the fluid run into the tubing until all of the air is flushed from the line.
Once this is done clamp the tubing to stop the fluid. At this point squeeze the IV tubing chamber so that it is half full. (The chamber is
the round portion of the tubing that is adjacent to the "Tubing - Bag" connection. Doing this allows you to monitor the rate of fluid
flow.)
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Place the tourniquet on the patients arm, and identify a target vein. Once you see or feel a suitable vein, try to determine its direction
by palpating the area. Doing this will help you approach the vein with an angiocatheter in the right direction. Finally clean the area
with an alcohol swab prior to catheter insertion.
Take the angiocatheter with the bevel (the needle is cut at an oblique angle) facing away from the skin and insert into the vein at a low
angle (approximately 15 degrees). Once you enter the vein blood will flow into the angiocatheter (called flashback). At this point only
the needle portion of the angiocath is within the vein, therefore advance the angiocatheter approximately 1mm to allow the catheter
portion to enter into the vessel lumen. (The needle portion is about 1mm beyond where the catheter portion starts) Now stabilize the
needle and advance the catheter into the vein.
Finally remove the tourniquet, place pressure at the tip of the catheter, and while securing the catheter with your fingers take out the
needle portion of the angiocath, leaving the catheter in place. Once the needle is removed quickly connect the IV tubing to the
catheter. Now secure the catheter with tape, unclamp the IV tubing and start the fluid. IV fluid should flow easily and this will confirm
that you are in the vessel lumen. If IV fluid does not flow easily you may need to reposition the catheter.
Emergency Equipment
Emergency equipment includes Yankauer suction, a device to provide for bag/mask ventilation with an oxygen source, emergency
medications, and emergency telephone numbers. A defibrillator and intubation equipment must also be available as required by state
law.