By: Jay B. Reznick, DMD, MD

Every day in practice, we treat patients who come into the office with a variety of medical conditions, some of which are a constant threat to their life, yet they usually come in and out of the dental office unscathed. It is possible to go through an entire career in dentistry, and never have a medical emergency occur in the office. But, more likely, we may go along for years without even a minor incident, and then one day, it happens. If the dentist is well-prepared, the outcome is usually favorable, but if not prepared, the patient’s life may end in the dental chair. Every member of the dental team should be trained in Basic Life Support, and emergency drills should be done periodically to ensure that everyone knows their role for an actual emergency, including how to activate the Emergency Medical System (EMS) in their town.

The best way to manage medical emergencies in the dental office is to try to avoid them in the first place. This requires a careful review of the patient’s medical history, including medications taken, and allergies. Patients with hypertension may be on medications that interact with the vasoconstrictor in local anesthesia, or that cause orthostatic hypotension, causing the patient to lose consciousness when getting out of the chair after a long dental appointment. Discontinuing high blood pressure medications abruptly for a dental procedure (to avoid drug interaction) can result in severe rebound hypertension, creating a severe hypertensive crisis, which can result in stroke or myocardial ischemia or infarction. If the patient has a cardiac pacemaker or implanted defibrillator, use of electrocautery in the office can cause a malfunction of the device. A patient with asthma may develop an acute attack in response to the stress of dental treatment. Finding out what precipitates a patient’s asthma and knowing how well-controlled the disease is may prevent a medical emergency in the dental office. These are just a few examples of how medical emergencies in the dental office can be prevented, or at least, minimized by using the medical knowledge that was gained in dental school, rather than dismissing it as unimportant in clinical practice. To cover prevention of medical emergencies completely would be a dissertation unto itself, and not leave enough space here to discuss their management, which is the goal of this essay. Excellent textbooks have been written on this subject, so these few thousand words will only be a cursory review of selected topics.

In order to fit into my allotted editorial space, but still give a somewhat complete discussion of these topics, I have divided this article into two parts. In this first installment, I will cover dental office emergencies that are characterized by an Altered Level of Consciousness (ALOC). Next month, I will conclude with other emergencies that are equally as important, but do not fit in that category, as well as my recommendations for a basic emergency kit for the office.

Altered Level of Consciousness (ALOC)
The most common medical emergency encountered in the dental office is vasovagal syncope, otherwise known as “fainting”. This condition is frequently first encountered by dentists in dental school, when local anesthetic technique is first practiced on classmates. Usually, the larger and more “macho” the student, the greater the likelihood of occurrence. This reaction is mediated by the parasympathetic nervous system in response to emotional or psychological stress, such as the sights and sounds in the dental office. The patient may complain of feeling weak and dizzy or nauseated, then may abruptly lose consciousness. Physical signs preceding syncope include pallor, sweating, nausea, rapid breathing, and tachycardia (pre-syncope). When the patient loses consciousness, there will be hypotension and bradycardia, irregular and decreased ventilation, and possibly convulsive movements (syncope). If the patient is not already in the dental chair, care should be taken to ensure that they are not injured on their way down to the ground.

When patients have experienced syncope or are pre-syncopal, they should be placed supine in the dental chair, with the feet elevated, and the head level with the heart, if possible. A patent airway should be established by lifting the chin and tilting the head (Fig. 1). Adequacy of ventilation should also be assessed, and supplemental oxygen should be administered. Vital signs should be taken, and monitored every five minutes. Restrictive clothing should be loosened and reflex stimulants, such as a cold compress on the forehead or ammonia inhalants should also be used. Syncope can be prevented in most patients by use of sedation and adequate pain control, treatment in the supine position, and appropriate food intake before a procedure.

Syncope is the most common cause of altered level of consciousness, but if the patient does not recover after a few minutes, or if the typical signs and symptoms are not displayed, other etiologies should be considered. These include hypotension, drug reactions, seizure, hypoglycemia, stroke, myocardial infarction, acute adrenal insufficiency, and hyperventilation (Table 1). The Emergency Medical System should be immediately activated. Every member of the office staff, whether front office, or back, should know how to do this. The patient’s medical history may give some clues to the etiology of ALOC. The patient’s vital signs should also be taken immediately, and every five minutes thereafter. The principles of Basic Life Support training should be followed at this point, with assessment of the patient’s Airway, Breathing, and Circulation. If there is no pulse, or respirations, then immediate CPR should begin. If there is a pulse, but no respirations, then rescue breathing should begin. Both should be performed using a bag-valve-mask device with supplemental oxygen, or a mask-to-mouth device (Fig. 2). If the patient is hypotensive, they should be placed with the legs elevated and head level with the heart. This increases venous return of blood to the brain and heart, so that blood perfusion is optimized to these vital areas.

Hypoglycemia can be a cause of acute ALOC in diabetic patients. Signs and symptoms can be similar to those in vasovagal syncope, and include mental confusion, lethargy, slurred speech, belligerent behavior, nausea, and diaphoresis with cold, clammy extremities. This will lead to unconsciousness, and possible seizures, followed by hypotensive shock and death. Immediate administration of glucose can rapidly reverse this downward spiral. Even if a history of diabetes is unknown, sugar should be given when the patient has displayed these signs and symptoms. If the patient is conscious, and symptoms are mild, a sugar-containing drink, such as orange juice or a soft drink can be given. For more severe reactions, a sugar paste is administered sublingually, or into the buccal sulcus. Cake icing is as effective as more expensive “medical” sources of dextrose. If unconscious, 50–100cc of intravenous 50% dextrose can be given over 2–3 minutes(Fig. 3). If there is no IV access, then 1mg of glucagon can be given IM. Sugar paste can also be massaged into the buccal sulcus in an unconscious patient, but it may take 20–30 minutes for the blood glucose level to rise sufficiently. If hypoglycemia is not the cause of ALOC, administration of this amount of glucose is not harmful. This situation can be prevented by appointing diabetic patients early in the morning or afternoon, just after meals. If the patient needs to be NPO for sedation, then the insulin dose should be modified accordingly. Usually, the patient is instructed to take one-half of their normal total insulin dose, in a long-lasting preparation, such as NPH. The pre- and post- procedure blood glucose level should be monitored, and intravenous 5% dextrose should be given intravenously during the procedure. For a long procedure, the blood glucose should be monitored intraoperatively.

Orthostatic Drug-induced effects can also cause an alteration in the patient’s level of consciousness. The most commonly administered drug in the dental office is a local anesthetic. Despite the use of aspirating dental syringes, inadvertent intravascular injection of local anesthetics occasionally occurs. A very small amount of intravascular local anesthetic usually does not cause any problems in healthy patients. The accompanying vasoconstrictor agent may cause a transient tachycardia, palpitations, tremor, headache, and hypertension. Except in very young children or the elderly, up to 13 carpules of 2% lidocaine with epinephrine can be administered over a 90-minute visit before toxic blood levels are reached (Table 2). If an intravascular injection occurs, especially with an arterial injection, signs and symptoms of toxicity can appear at much lower doses. The patient may appear anxious, light-headed, confused, drowsy, euphoric, may complain of nausea, blurred vision, and/or dizziness. These symptoms, in any combination, can be followed by unconsciousness and respiratory arrest. There can also be cardiovascular depression, with bradycardia, hypotension, and cardiac arrest. Drowsiness after administration of lidocaine is usually an early sign of an elevated blood level, which may occur secondary to rapid absorption. Treatment involves maintenance of the airway and ventilation, control of seizures with ultra-short acting barbiturates or benzodiazepines, if they persist, and general supportive care with intravenous fluids. This emergency can be prevented by careful administration of local anesthetics, using an aspirating syringe, monitoring of the patient, and ceasing injection and administration of oxygen at the first sign of toxicity. Toxicity with other local anesthetics presents in a similar fashion, so only lidocaine will be discussed under this heading. The other emergency that can occur with injection of a local anesthetic is an allergic reaction. These are more common with ester-type local anesthetics, but extremely rare with the more commonly used amide-type anesthetics. Discussion of allergic reactions will be under that topic.

The anxiety induced in some patients in the dental office can lead to the hyperventilation syndrome, resulting, ultimately in loss of consciousness. This may be purely psychogenic, or may be in response to procedural pain. Signs and symptoms of this condition include rapid respiratory rate (25-30/minute), dizziness, chest tightness, dyspnea, trembling, diaphoresis, palpitations, hypertension and tachycardia, and complaints of difficulty swallowing or breathing. Patients will characteristically report tingling in the hands, feet, and perioral areas. If not aborted, this may progress to carpopedal spasm and loss of consciousness. The patient should be immediately positioned sitting upright, as the supine position tends to increase anxiety. They should be calmed and reassured that you will help them through this episode. The patient should be guided in slow breathing (6–10/minute), ideally into a paper bag. This rebreathing of exhaled air helps correct the respiratory alkalosis induced by hyperventilation. Vital signs should be monitored, and if the patient fails to calm, intravenous benzodiazepines can be used. This is a medical emergency that can be prevented by providing appropriate sedation and pain and anxiety control measures in susceptible patients.

Another potential cause of ALOC is acute adrenal insufficiency. This may occur in patients who are on chronic corticosteroid medication for a variety of medical problems, including severe pulmonary disease, collagen-vascular disorders, severe arthritis, and severe skin diseases. Daily exogenous administration of 20 mg or more of hydrocortisone (or equivalent) for two weeks or longer, within two years can result in suppression of normal adrenal function and production of cortisol. Cortisol is involved with regulation of glucose utilization and blood pressure, and hence, modulates the body’s response to physiological or psychological stress. The signs and symptoms of acute renal insufficiency include confusion, fatigue, muscle weakness, nausea and vomiting, intense pains in the abdomen, lower back and/or legs, hypotension, and tachycardia. If not treated promptly, this can lead to loss of consciousness, circulatory collapse, shock, and death. The EMS should be immediately activated if acute adrenal insufficiency is suspected. With the patient supine in the dental chair, oxygen should be delivered at 6-8 liters/minute, and 100 mg of hydrocortisone, or its equivalent, (Table 3) should be given intramuscularly or intravenously. If intravenous access is established, fluid resuscitation with D5W should be started. This medical emergency can be prevented by taking a complete medical history. If the patient is at risk of adrenal suppression by exogenous steroids, they should be supplemented by taking an additional oral dose the night before and the day of the procedure. Adequate pain control and possible sedation also help reduce the stress associated with the dental procedure.

Seizures are due to paroxysmal discharge of neurons in the brain, which leads to abnormal behavior or perception, or uncoordinated muscle activity and loss of consciousness. They may be idiopathic in origin, or secondary to central nervous system infection, toxic or metabolic insult, or trauma. Grand mal seizures (tonic-clonic) begin with a prodromal phase in which the patient may have a visual, olfactory or auditory aura, and changes in personality. This is followed by the ictal (convulsive) phase, during which the patient loses consciousness, develops generalized clonic movements, may become cyanotic and become incontinent. The postictal phase is characterized by a gradual return of consciousness, disorientation and confusion. Management is directed toward preventing injury. The patient should be placed supine on the floor, with the head turned to the side, and protected with a pillow. Nearby objects that may cause harm should be removed. Attention should be directed to the patient’s airway, to ensure obstruction does not occur. Oxygen should be administered if the patient becomes cyanotic, and vital signs should be monitored during recovery. Gathering a complete medical history, including compliance with medications is an important consideration in preventing this emergency. Avoidance of physical or psychological stress or fatigue, and watching the amount of local anesthetic given, to avoid toxic doses, are also important in prevention.

Angina Pectoris is an acute onset of chest pain due to insufficient coronary blood flow, resulting in ischemia of heart muscle. This is generally secondary to coronary artery disease, with episodes generally brought on by physical or emotional stress. Episodes are usually characteristic and consistent for each patient. The pain is usually substernal, and may radiate to the left shoulder, arm, neck, or jaw. As with a myocardial infarction, episodes of angina may also be associated with tachycardia, palpitations, faintness, dizziness, nausea, hypertension, diaphoresis, and dyspnea. Patients with a history of angina pectoris usually carry nitroglycerine with them at all times, and are familiar with its use. They may have attacks many times per week or month. Minor angina pain usually lasts a few minutes, and will disappear with rest and supplemental oxygen. Patients should be seated comfortably, usually upright. If the symptoms fail to resolve promptly, the patient should be given sublingual nitroglycerine, preferably from their own supply. If this is not available, a 0.4mg sublingual tablet or 0.4 mg metered sublingual spray should be administered (Fig. 4). Nitroglycerine can be absorbed through the skin, so the tablets should not be touched, except by the patient. Many prefer the sublingual spray, as the tablets have about a three-month shelf life after the bottle has been opened. A second and third tablet may be given at five-minute intervals if relief is not obtained. If angina pain is not relieved after the third dose, it should be assumed that the patient is having a heart attack.

Myocardial infarction can also lead to loss of consciousness. The typical presentation is of substernal chest pain, which radiates to the left arm. This is actually seen in only 25% of cases. Pain may also radiate to the mandible, and may be the only presenting symptom, mimicking a toothache. Patients having a heart attack are often restless, and may appear very apprehensive and feel impending doom. Other symptoms include diaphoresis, nausea, weakness and dyspnea. About 15–20% of myocardial infarctions can occur without chest pain, especially in diabetic patients. Frequently, the patient will have a history of angina pectoris. However, this is not universal. In a patient with a history of angina, chest pain that is not relieved by the usual dose of nitroglycerine, varies from the patient’s typical angina, or that lasts longer than their typical angina, myocardial infarction should be assumed. The EMS should be immediately activated, and the patient placed in a comfortable position. This is usually upright. Oxygen should be administered at a high flow rate (>_8 liters/min), and the patient should be given an aspirin (325 mg) to chew, allowing absorption through the oral mucosa. An intravenous line should be started, if available, and infusion with normal saline begun. Again, if available, 2–8 mg of morphine sulfate should be slowly titrated to relieve pain and anxiety. If the patient loses consciousness, properly performed Basic Life Support should be initiated immediately, and continued until emergency medical personnel arrive to assume care and transport to the hospital. If the dentist is trained in Advanced Cardiac Life Support, and equipment is available, then this should be begun as indicated.

In patients with a known history of cardiovascular disease and/ or angina pectoris, elimination of anxiety and stress associated with dental treatment is a key to prevention of cardiac emergencies in the office. This can be accomplished with the appropriate use of oral or intravenous sedative medications, supplemental oxygen by nasal canulla during procedures, and prophylactic nitroglycerine given before any injection or stressful procedure.

The final medical emergency, to be discussed here, associated with altered level of consciousness is stroke, otherwise known as a cerebrovascular accident, or CVA. This condition is analogous to a myocardial infarction, or heart attack, in that there is infarction and necrosis of brain tissue. It has, therefore, also been called “brain attack”. The majority of strokes are due to obstruction of blood flow, but some are due to intracerebral hemorrhage. The exact physical findings and symptoms depend on the specific area of the brain affected, but generally include headache, dizziness, nausea and vomiting, sweating, chills, hypertension, and loss of consciousness. Focal neurological signs, such as facial and muscular weakness or paralysis, difficulty with speech, and incontinence also frequently occur. Treatment is directed toward assessment of the ABCs, supplemental oxygen, supine positioning, and activation of the EMS. Again, prevention is dependent on obtaining a complete medical history, and stress reduction measures, such as mild sedation and adequate pain control.

Following the principles of Basic Life Support, assessment and management of the Airway, Breathing, and Circulation, is essential to a favorable outcome in all medical emergencies. Staff preparation, including regular emergency drills, helps to improve the chances of successful resuscitation of the patient who loses consciousness in the dental office. In next month’s issue, I will conclude with a discussion of some other common office emergencies, as well as recommended emergency supplies for the dental office.

Dr. Reznick received his undergraduate biology degree from CAL-Berkeley, dental degree from Tufts University in Boston, and his MD degree from the University of Southern California. He did his internship in General Surgery at Huntington Memorial Hospital in Pasadena and trained in Oral and Maxillofacial Surgery at L.A. County––USC Medical Center. He is an Assistant Clinical Professor at USC and is a Diplomate of the American Board of Oral and Maxillofacial Surgery. His special clinical interests are in the areas of facial trauma, jaw and oral pathology, dental implantology, sleep disorders medicine, laser surgery, and jaw deformities. He also has expertise in the integration of digital photography and imaging in clinical practice. He is a Partner in the Southern California Oral and Facial Surgery Group, with offices in Tarzana, Encino, and Westlake Village, California. Dr. Reznick can be reached on the www.dentaltown.com message boards or through email at jreznick@scofsg.com. Address for Correspondence and Requests for Reprints: Jay B. Reznick, DMD, MD 18372 Clark St., Suite 233, Tarzana, CA 91356 and Dentaltown Magzine.

GENERAL REFERENCES:
1. Cummins RO, Ed.: Advanced Cardiac Life Support. American Heart Association. 1997.
2. Donoff RB. Massachusetts General Hospital- Manual of Oral and Maxillofacial Surgery. Mosby, St. Louis, MO. Third Edition. 1997.
3. Hazinski MF, Cummins RO, Field JM, Eds. 2000 Handbook of Emergency Cardiovascular Care for Healthcare Providers. American Heart Association. 2000.
4. Malamed, SJ. Medical Emergencies in the Dental Office. Mosby, St. Louis, MO. Fifth Edition. 2000.
5. Physicians’ Desk Reference. Thomson PDR. Montvale, NJ.57th Ed.: 2003