1. INTRODUCTION
Fortunately, medical emergencies in the
dental office are a rare occurrence.
Unfortunately, this rarity prevents us from becoming comfortable with
management of problems, and worse still, may lead to complacency. In light of their uncommon occurrence, it is
useful to revisit the subject, sometimes from a different perspective. The perspective taken for today's discussion
is a relatively broad one, allowing for a
"from first principles " approach to the prevention of
preparation for, recognition of and action involved in the management of
medical emergencies.
2. DEFINITION
A medical emergency is a stress induced,
relatively sudden, acute, uncontrolled failure of physiologic adaptation
capability (or decompensation in the face of stress ).
A. Stress
induced: This implies that there is usually a more or
less recognizable cause or identifiable stress that is driving the system
toward failure. This could be the
presence of an allergen, anxiety, drugs or foreign object in the airway that
stresses the system maximally and beyond in such a manner that the system is no
longer able to cope.
B.Relatively sudden: While some
emergencies occur rapidly, many take time to evolve. An identifiable, gradual chain of events
often conspire to lead a patient to the point where they are maximally stressed
and failure occurs as the last link in the chain. Prevention centres on breaking the chain of
events prior to reaching failure.
C. Acute: The central theme of all emergencies is
that they are acute occurrences happening right now. From this perspective they require immediate
recognition and attention.
D.Uncontrolled
failure:
Emergencies rarely display intrinsic control by the patient. Clearly, the patient’s system has lost the
ability to respond to the stress and extrinsic help must be brought in. The key to management of emergencies is the
resumption of control by the clinician.
E.Decompensation: Loss of compensation implies that
compensation was happening in the first place.
In the normal healthy subject, this ability to compensate for stress or
strategic reserve is maximal and much has to happen before the system is no
longer able to adapt to rising levels of stress. In the medically compromised patient, some of
this reserve has been lost as a function of the underlying illness and
decompensation or failure occurs earlier and in the face of lower levels of
stress.
F. Examples:
An excellent model for medical emergency is
the coronary stress test. In this
example, the stress is the treadmill, specifically related to its slope and its
rate. As the slope and rate of the
treadmill increases, the stress to the heart and the demand for coronary
perfusion of the myocardium increases.
While
the angina attack or the MI that the patient experiences while having the test
is a relatively sudden event, the steps leading to the acute event took place
over a well defined interval and occurred in a clearly laid out pattern.
Although the progression to the angina
attack or the MI may have been drawn out, the event itself is acute and must be
recognized and dealt with immediately by the stress lab technician. If the
patient has gone on to having an MI during the stress test, the extent of the
damage is essentially uncontrolled unless the technician intervenes, stops the
test and begins supportive management immediately.
The
stress test is designed to assess the patient's coronary reserve.
"Failing" a stress test means the patient's reserve was minimal in
the first place and that decompensation or failure is likely to occur very
early in the process of applying stress to the system.
What is a medical emergency?
A
medical emergency can be described as any situation in which a patient becomes
ill, may become unconscious and ultimately their life may be at risk due to a
failure of an effective oxygenated circulation to the brain and vital organs.
There are certain specific emergencies that are the most commonly encountered
in General Dental Practice and all DCPs should be familiar with their
presentation and management, these are shown in table 1.
Table
1 :Specific Medical Emergencies
·
Choking
·
Asthma
·
Anaphylaxis
·
Hyperventilation
·
Respiratory
arrest
·
Angina
·
Myocardial
infarction
·
Seizures
·
Faints/syncope
·
Cerebro-vascular
accident (stroke)
·
Cardiac
arrest
3. THE CORNERSTONES OF EMERGENCY MANAGEMENT
Viewed from this perspective, the
management of emergencies can be thought of as occurring in four domains. Each domain is interdependent with the other
domains and requires support form the other three.
Prevention: The most successful way to manage an
emergency is to prevent it form happening in the first place. This is based on:
a)
An assessment of relative risk: This is the ‘product’ of medical compromise
multiplied by the complexity of the procedure.
The more ill the patient and the more invasive the procedure, the
greater the likelihood of an emergency. Careful
medical assessment is the key to determining where the patient is sitting on
the compensation curve, and therefore, their medical risk.
b) Risk reduction and hazard avoidance: Having recognized increased risk (as a
function of illness and procedural
complexity), prevention revolves around risk reduction (medical tune up in
order to ensure optimal control of medical compromise) and hazard avoidance
(reduce anxiety, avoid allergens, avoid drug interactions, reduced pain,
shorter procedures, avoid aspiration, refer, etc.).
B. Preparation:
a)
Medical assessment: Careful medical assessment not only allows for
identification of risk and thus avoidance, it should also give the practitioner
an indication of the type of medical emergency that the patient may have, for example:
bronchospasm in the asthmatic.
Having this information readily at hand when dealing with an emerging
problem will save on considerable guesswork and allow the practitioner to zero
in on the most likely diagnosis.
b)
Emergency kit: An important aspect of preparation for emergencies is the
purchase and careful maintenance of an emergency kit. This should include key drugs and equipment
needed to manage emergencies. A key
example of this is to ensure that there are syringes and needles for the
delivery of emergency drugs when needed.
A further point to stress is the need to monitor expiration dates and
the condition of equipment such as airways or masks. The following is a short list of recommend
drugs and equipment:
1.
Oxygen 6
1/min by mask
2.
Epinephrine (alpha and beta agonist) 0.5
to 1 ml of 1:1,000 IM
3.
Nitroglycerine (vasodilator) 0.3
mg sublingual to 3 doses (if no
response…assume MI and call 911)
4.
salbutamol (Ventolin) (bronchodilator) 2 puffs by inhalation
5.
diphenhydramine (Benedryl) (antihistamine) 50 mg IM or PO
6.
Sucrose soda
PO
7. Glucagon 1
mg IM
8.
ASA 325
mg PO
9.
Lorazepam 1
mg SL
10. Oxygen bottle with regulator and gas
tubing
11. An assortment of adult and paediatric
airways and face masks
12. Ball valve bag for ventilation
(Ambubag)
13. Various syringes and needles for
delivery of emergency drugs
14. Tape
15. Flashlight
16. Tonsil suction tip
17. File cards with emergency protocols
and drug dosage information
c)
Clear guidelines: During the middle of a medical emergency is no time to be
figuring out what to do next. This has
been recognized by the American Heart Association in their guidelines for CPR
and ACLS (Advanced Cardiac Life
Support). These guidelines, once learned, allow the rescuer to follow standard
protocols for the management of cardiac emergencies. They are based on sound judgement and
scientific study and most importantly, are detailed IN ADVANCE. Similar thinking for the management of other
emergencies is equally reasonable.
Taking the time, in advance, to think through an emergency situation,
outlining it on a file card, familiarizing all staff, in advance, and then
placing the card in the emergency kit will tremendously simplify problem
management.
d)
Practice: The AHA again recognizes the
importance of rehearsal for the management of
emergencies. Annual mock emergencies not only keeps the staff sharp but it is
also an excellent opportunity to recheck the emergency kit and restock stale
dated medications.
e)
Vigilance: Watching and listening for
potentially emergent situations whether they be in the operatory, the other
operatory or the waiting room will help to prevent problems before they occur
and to act on emerging problems early in their progression. This requires constant vigilance and
observation for the patterns of "
problems waiting to happen".
Recognition: Early recognition and intervention is
essential to the successful management of emergencies once they have
happened. The comment, " the right thing was done too late
" may be the epitaph for the
unsuccessful emergency intervention.
a)
Monitoring: Monitoring of patients takes many forms. The most extreme is
intensive ICU or OR monitoring that
involves EKG, pulse oximetry, blood pressure and so on. In the normal dental office, these items are
usually unnecessary and unfamiliar. What
is done is moment to moment monitoring through assessment of colour,
respiratory rate and distress pattern, level of consciousness and observation
of overt signs of distress. Dentists are
particularly good at this sort of monitoring because we are constantly watching
for signs of discomfort or inadequate anaesthesia that may complicate our
procedure. The most useful practical
technique is the comparison of patient's state of mind as we progress through
treatment. How often have you asked a
patient " are you OK", after
observing some subtle mood or postural
change in the patient? This type of monitoring
is crucial for the detection of problems early in their progression.
b)
Context: The importance of an accurate and up-to-date medical history cannot be
overstressed. If a patient is
decompensating, it is usually a function of a lack of strategic reserve in a
given system and it is usually obvious from the medical history. A patient with a history of six heart attacks
in the past is likely having another one if he collapses in your waiting room. This allows for early diagnosis and
appropriate management.
c)
Assessment of severity: Determining the severity of a problem is a function of
the interplay of a complex series of observations and then the performance of
mental arithmetic in order to extrapolate ahead and try to predict just how bad
things might get and how soon they might get there. If a patient was fine two minutes ago and is
now swelling visibly and wheezing audibly following the administration of a
local anaesthetic, its a good bet that he going to continue getting worse in a
hurry. This determination of how severe
things are (and how severe they are going to get) directs management in terms
of the intensity of response. The above
noted patient needs epinephrine right now and an ambulance ride as soon as
possible if he hopes to survive the day.
On the other hand a simple episode of syncope from which the patient
recovers quickly may only require repositioning and reassurance before resuming
the treatment. Measurable parameters
like heart rate, blood pressure and respiratory rate are much more objective
guides to the ongoing status of the patient and as such will be very helpful in
determining whether a patient is worsening or improving.
d) Diagnosis and differential
diagnosis: In some cases, the diagnosis will be obvious. Examples of this are epileptic convulsions or
airway obstruction following loss of a crown down the patients's throat. In these cases, the obvious diagnosis leads
to early appropriate management. In other situations, the diagnosis of the
emergency situation may be obscure. An
unconscious patient lying on the floor of your waiting room may have fainted,
overdosed on drugs, hypoglycaemic, dead, having a heart attack or simply be
asleep. Having a working differential
diagnosis will direct the early steps in managing this situation to supporting
the basic ABC's and to determining the
exact nature of the problem. Quick
review of the medical history is often helpful at this point. In other circumstances, the results
of early intervention may be diagnostic if
applied appropriately. An
excellent example of this is the patient with chest pain. If the nitroglyercine does not clear up the
problem after three dosages, then a call to the ambulance and a trip to the
local emergency room is indicated to rule out an MI.
Action: Action may be indicated even before an
emergency situation is clearly diagnosed.
Supportive measures such as airway maintenance will buy valuable time
for the clear determination of the problem and definitive intervention.
1. Stop the procedure and manage the emergency.
2. ABC's of emergency management: airway, breathing and circulation
3. 911....... Get help as soon as the situation
appears serious
4. On the basis of diagnosis:
a) Maneuvers, eg. Trendellenberg position, Heimlich
maneuver
b) Drugs......see emergency kit and protocol
card
c) Follow up........911 (ambulance), emergency
room or physician
How do you “manage” an emergency?
The
ability to effectively manage a medical emergency is dependent on three things
which are all inter-related:-
- Theoretical
knowledge.
- Practical skills
- Team work
Theoretical knowledge
This
includes an understanding of the basic physiology of the vital organs and
systems of the body, together with detailed knowledge of the causes, effects
and treatment of the more common emergencies.
There are several textbooks available which are useful sources of
reference and a list of useful websites is provided at the end of this article.
Practical skills
There
are specific skills that are required to effectively assess and treat a patient
who is feeling unwell, or who has collapsed.
It is not always immediately obvious what the cause of the problem is,
but this does not preclude effective management. A systematic assessment of the patient is
essential, and the universally accepted method is the ABCDE approach. The only way
to acquire practical skills is simulation training which allows for constant
repetition of the skill until the individual develops the appropriate level of
competence. The knowledge and skills are
briefly described below:-
A=Airway
A
person must have an open airway to allow oxygen to enter the lungs, so the
first step in effective management is to assess the patency of the upper
airway-the patency is obvious if the patient is talking ,however ,if the
patient is unconscious. are there any obvious obstructions e.g. fluid, vomit,
or the tongue?
A=Airway
A
person must have an open airway to allow oxygen to enter the lungs, so the
first step in effective management is to assess the patency of the upper
airway-the patency is obvious if the patient is talking ,however ,if the
patient is unconscious. are there any obvious obstructions e.g. fluid, vomit,
or the tongue?
Airway skills
Know the location of the
emergency suction and how to use it.
Deal effectively with
choking-back blows; abdominal thrust.
Ability to place an
unconscious patient into the “recovery position”
Jaw thrust
Head tilt chin lift
Insertion of oro-pharyngeal
airways
Insertion of naso-pharyngeal
airways
B=Breathing
If
the airway is open then a person must be breathing effectively to draw inspired
oxygen into the lungs. Noisy breathing
is indicative of an obstruction, and the type of noise produced will indicate
the possible cause e.g. bronchospasm producing an expiratory wheeze in asthma
and anaphylaxis. Administration of oxygen is essential, and if a person is not
breathing then ventilations need to be supplied.
Breathing skills
Location of emergency oxygen
and how to attach this to the relevant face mask.
Assembly and use of a pocket
mask
Assembly and use of a
bag-valve mask
Ability to deliver effective
ventilations.
Ability to assess respiration
for:-
- Rate
- Depth
- Noise
- Use of
accessory muscles
- Bilateral
chest expansion
C=Circulation
- An
effective circulation is essential to ensure an adequate supply of
oxygenated blood reaches all vital organs.
In a medical emergency this can become compromised and therefore
needs to be monitored, and in a cardiac arrest external chest compressions
need to be supplied.
Circulation skills
- Ability
to measure central and peripheral pulses for rate, regularity, volume.
- Ability
to measure blood pressure
- Measure
and understand the significance of capillary refill time
- Ability
to perform effective cardiac compressions at a rate of 100 per minute
- Safe use
of an automated external defibrillator if the practice has one.
D=Disability
- This is
an assessment of the effect the emergency is having on the patient’s brain
and nervous system. The two things
that are essential for the brain to function effectively are an adequate
supply of oxygen and glucose, if these are not supplied then the patient’s
level of consciousness will be affected.
The method of assessment of conscious level is the AVPU scale, a further
useful test is the response of the pupils of the eye to light. Blood glucose level can be measured
using a suitable monitor.
Disability skills
- Use the
AVPU response scale to assess consciousness ( Alert; responding to Voice;
responding to Pain; Unresponsive)
- Assess
pupil reaction and understand the significance
- Ability
to use a blood glucose monitor.
E=Exposure
- This
assessment is a physical examination of the patient which will be limited
in a dental surgery setting. The
main things to be considered are rashes/ flushing, any signs of swelling
around the mouth and face, and prevention of heat loss.
Exposure skills
- Record any flushing or rashes
- Know the location of blankets within the
practice
The
use of this systematic assessment will provide essential information about the
nature of the emergency and which body systems are being affected, it is not
always necessary to have a specific diagnosis to provide effective treatment to
compensate for the problem. This
assessment is carried out each time something changes e.g. the patient becomes
unconscious, and each time an intervention is done e.g. the respiration rate
was 30 per minute but after oxygen was supplied it reduced to 20 per
minute-this is reassuring that the intervention carried out was effective. It is good practice to write down the
assessment results each time it is carried out and this will provide valuable
documentation for the paramedics on transfer.
Emergency Drugs
All
dental practices carry an emergency drugs kit and all team members should know
the location and content of this kit.
The presentation of emergency drugs varies quite considerably and
therefore practice may be required to actually prepare the appropriate drug for
administration e.g. how to assemble a syringe.
It is good practice for all team members to train to do this, using
preparations that are out of date, to avoid confusion and delay if drug
administration is required. A summary of
the emergency drugs and their use is given in table 2.
Emergency drug skills
Know the location of the emergency drug box
Know the type of drug and dose required for which
emergency
Understand the different methods of drug delivery
(inhalational ,oral; transmucosal; intra-muscular and intra-venous)
Practice assembling the drug ready for
administration
Practice intra-muscular administration using a simulator.
Paramedic Transfer
The
last responsibility the dental team has is to transfer the patient safely into
the care of the paramedics. It is good
practice to ensure that all the information required is provided as written
documentation for ease of reference. The
acronym SAMPLE or MAPLES provides a useful “aide –memoir” to ensure all the
appropriate details are included.
Paramedic
Handover-essential information
Symptoms
Allergies
Medications
Past Medical History
Last oral intake
Events prior to the incident
3. Team work
All
members of the dental team should undertake regular scenario training within
the dental practice. This will help to
increase the confidence and competence of each individual team member with
their individual roles and responsibilities.
Each time a scenario is conducted the team members should alternate
roles so all aspects of the management of the emergency are rehearsed. All scenarios should end with a practised
“paramedic handover” including provision of all documentation. Attendance at lectures and external courses
can be very beneficial but are no substitute for regular “in house” training.
Team
roles and responsibilities
Who acts as the team leader and directs the team?
Who is responsible for locating and preparing the emergency
equipment and drugs?
Who is keeping a note of the time and recording the results of
the assessments?
Who contacts the paramedics and waits by the entrance to lead
them to the emergency?
Who is responsible for collating and photocopying the necessary
documentation?
For each
of the following sample emergencies, consider the affected system, the
pathophysiology of the emergency and add detail with respect to the mechanisms
of action, dosages and routes of the emergency drugs.
E. Sample Emergencies:
Medical Problems which may alter dental treatments
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| Medical Problems which may alter dental treatments |
