By: Jay B. Reznick, DMD, MD

Allergic reactions
Allergic reactions are due to a hypersensitivity response to a particular antigen. It can be delayed or immediate. A patient can develop an allergy to any medication or substance after repeated exposures to it. This can occur without any warning signs. Allergic reactions are generally immunoglobulin E (IgE) mediated responses. A sensitized mast cell releases vasoactive and inflammatory mediators within minutes after exposure to the specific antigen. Clinical findings can be mild and involve only cutaneous signs, or may be immediately life threatening and lead to cardiovascular shock and death. One of the most important factors in assessing the severity of an allergic reaction is the rate of onset of signs and symptoms.

A mild allergic reaction may occur an hour or more after the oral administration of an allergen, or many minutes after parenteral administration. Cutaneous signs are the most common manifestations of a mild allergic reaction. These include itching, urticaria, redness and edema. There can also be ocular reactions, such as conjunctivitis and watery eyes. A more severe allergic reaction can also include wheezing, chest tightness, and tachycardia. Angioedema of the face, lips, eyes, mouth, and airway can also accompany the allergic response.

A severe, rapid onset, systemic allergic response is known as anaphylaxis. This is a true medical emergency, requiring immediate action. In addition to the above cutaneous and respiratory signs and symptoms, there may also be nausea, vomiting, abdominal cramps, diarrhea, hypotension, arrhythmias, laryngospasm, bronchospasm, airway obstruction, and loss of consciousness. This may rapidly progress to cardiac and circulatory collapse. It is important to appreciate that skin manifestations may precede more serious cardiovascular and respiratory problems, and that early recognition and treatment may prevent progression to a serious medical emergency. Again, the most important factor in assessing the severity and seriousness of the condition is the rate of onset of signs and symptoms.

Initial treatment for all allergic reactions is the immediate administration of 50 mg of diphenhydramine (Benadryl), along with identification and removal of the antigen. Intravenous or intramuscular injection is most rapidly effective. If injection is not available, it should be given orally. The patient’s response should be monitored, and if the allergic reaction is mild, and aborts with this treatment, then diphenhydramine should be repeated orally at 50 mg every six hours for 24–48 hours.

If the onset is rapid and more severe symptoms and signs are present, the Emergency Medical System (EMS) should be activated. Assess and manage the patient’s ABCs, administer 100% oxygen and provide basic life support as indicated. Epinephrine is the drug of choice for management of a severe allergic or anaphylactic reaction. An initial dose of 0.3–0.5 mg (0.3–0.5 ml of a 1:1000 solution) should be given intramuscularly or subcutaneously. This can be repeated every 10–15 minutes if necessary. An additional dose of diphenhydramine 50 mg or hydrocortisone 100 mg can be given to help prevent a recurrence of symptoms.

Asthmatic attack/bronchospasm
Asthma is a paroxysmal state of hyper-reactivity of the tracheobronchial tree. When an external allergen causes an antibody-mediated bronchospasm, this is referred to as extrinsic asthma. It most commonly occurs in children. When non-allergic factors, such as emotional stress, respiratory infections, irritating vapors, or physical activity cause the bronchoconstriction, this is known as intrinsic asthma. This is more common in adults. Obtaining a good medical history is important in the prevention of asthmatic attacks in the dental office. It is important to ask the patient about the frequency and severity of attacks, as well as what precipitates them. Other clues to the severity of a patient’s asthma include the number and types of medications they are taking, as well as history regarding emergency room visits and hospitalizations related to the asthma. Treatment with bronchodilator inhalers, such as albuterol or metaproterenol, used only as needed, may indicate a mild asthmatic. More severe cases are treated with prophylactic medications, such as corticosteroids, cromolyn, beta-2 agonists, and leukotriene modifiers (Singulair).

Signs and symptoms include wheezing (usually greater with expiration), chest tightness, non-productive cough, and dyspnea. Patients will usually try to sit up to try to facilitate breathing. More severe attacks will also present with anxiety, tachycardia, cyanosis of the nail beds, the use of accessory muscles of respiration (sternocleidomastoid, shoulder and abdominal muscles), and nasal flaring. Immediate management includes discontinuation of treatment, placing the patient in the most comfortable position (usually upright with the arms outstretched), and administration of two puffs of a bronchodilator inhaler (albuterol or metaproterenol), followed by the administration of oxygen (Fig. 1). If the attack continues, the EMS should be activated, and subcutaneous or intramuscular epinephrine (0.3 mg) should be administered. The albuterol inhaler can be repeated every two minutes, and the epinephrine every 10 minutes if necessary. Intravenous or intramuscular hydrocortisone (100 mg, or equivalent) may also be helpful, if the asthma attack was precipitated by an exogenous allergen.

Minimizing patient anxiety with appropriate pain control and sedation techniques helps prevent intrinsically triggered asthma attacks. The clinician should also ensure the patient has been taking their asthma medications as prescribed prior to dental treatment. The patient should have his/her own medication available for use in the event of an asthma attack. If the patient has frequent attacks, prophylactic use of the inhaler just before dental treatment should be considered.

Hypertensive crisis
Hypertension is clinically defined as a systolic blood pressure greater than 140 mm Hg or a diastolic blood pressure greater than 90 mm Hg. Patients with a diagnosis of hypertension are seen in dental practice every day. Most of them have their blood pressures well controlled with medications. These can include beta-blockers, diuretics, calcium channel blockers, and ACE (angiotensin converting enzyme) inhibitors. On occasion, a patient will have a significantly elevated blood pressure in the dental office. Most of the time, this is related to anxiety and is transient in nature. Other times, it may be due to noncompliance with prescribed medications, ingestion of adrenergic agonist drugs, or due to an undiagnosed medical condition, such as a hyperthyroid state or undiagnosed pheochromocytoma. This underscores the importance of routine measurement of blood pressure in the dental office.

Patients taking antihypertensives should continue to take their medications as prescribed before a dental procedure, even when intravenous sedation is to be used. Abrupt discontinuation of medications can result in a life-threatening rebound hypertension. Taking the medication with a few sips of water will not violate their preoperative NPO status.

Patients who are seen in the office with a systolic blood pressure between 140–160 or a diastolic pressure between 90–100 can receive routine dental treatment without risk of significant complications, but should be seen by their physician for evaluation of the elevated blood pressure as soon as feasible. Treatment should be deferred until after medical evaluation and management if elevated beyond these limits (> 160/100). Blood pressure greater than 200/115 is a medical emergency. These patients should be referred to their physician or the closest emergency room immediately.

Foreign Body in eye
In the operating room, patients are draped so that only the surgical field is exposed. In the dental office, the patient’s entire face is exposed to the treatment team. Although care is taken not to pass instruments or supplies over the patient’s upper face, occasionally, a fragment of a dental material may end up in the eye of a patient. More commonly, a small foreign particle in handpiece aerosol is the cause. Most small fragments are stopped by the surface of the cornea or conjunctiva, but become “stuck” to the eye by the movements of the eyeball and eyelids. Many small particles find their way to the to the conjunctival folds of the upper and lower eyelids. These can usually be removed by eversion of the eyelid over a cotton swab with the patient looking away from the involved eyelid. Once visualized under good light, the foreign material can be flushed out using an isotonic ophthalmic irrigating solution, such as BSS (Balanced Salt Solution) or a prepared eye wash solution (Fig. 2). If the patient still complains of a foreign body sensation in the eye, they should be referred to an Urgent Care facility or Ophthalmologist to evaluate for residual debris or a corneal abrasion. These are managed by instillation of an antibiotic solution into the eye along with pressure-patching and possibly cycloplegic drops. These injuries usually show significant healing in 24 hours.

Foreign Body Aspiration/Airway Obstruction
We are taught in dental school and specialty training programs to always protect the patient’s airway. Yet, we all remember an incident from school or have heard of one in practice in which a small instrument or prosthesis found its way to the back of a patient’s unprotected throat. If they were lucky, airway protective mechanisms were intact, and the foreign body found its way into the esophagus rather than the trachea. The best way to manage this situation is through prevention. A rubber dam affords the best protection to the airway, and should be used whenever feasible for restorative procedures. For surgical procedures, and those in which a rubber dam cannot be used, a throat pack or “curtain” should be utilized. A 4x4 gauze or even a 2x2 will work as a throat pack, as long as it prevents anything from passing to the back of the throat if dropped. The key is correct placement to protect the airway. The throat pack should be of adequate size to completely partition off the area you are working in from the back of the throat. If you are working in the anterior area, you can place it directly behind. In the posterior, it is placed more toward the working side, so that if anything falls, it will be caught by the gauze before it can pass to the back of the pharynx. With the pack correctly positioned, you should not see the back of the patient’s throat. If an object gets past the throat pack, it should only be removed under direct visualization. Attempting to blindly remove it may push it further down the pharynx.

If a foreign object enters the trachea, the patient will usually cough, as the object passes the epiglottis. That is where the sensory nerve endings are that protect the airway by closing the epiglottic folds. When you get food/liquid down the airway, that is where you feel it. If the object passes right through without stimulating the cords, it may pass into the bronchial tree without the expected cough. There are very few sensory nerves in the bronchial tree. Usually, the foreign object will cause irritation, resulting in fluid exudate into the lungs. This will lead to development of a cough, fever, malaise, etc. a few days later. Even when it seems certain the object was swallowed, and not aspirated, it is always best to be safe and radiographically examine the chest and abdomen, to verify the location of the object. If it is in the tracheobronchial tree, it will need to be removed endoscopically by a trained physician. If in the gastrointestinal tract, usually only observation is necessary, until the foreign body passes out the rectum with the feces. Even sharp, irregular objects (keys, safety pins) are known to pass safely through the gastrointestinal tract, without damage to the serosal lining, so endoscopic removal is rarely, if ever, necessary. A stool softener, such as docusate sodium (DSS), or mineral oil is recommended to ensure safe passage.

Emergency Kit/Supplies
An important key to deciding what drugs to put in your emergency kits is to have ONLY drugs you are familiar with, and know how to use correctly. An office emergency is different than something occurring outside, where the “Good Samaritan” laws will protect you if you use a medication or device inappropriately. Do not waste your money on ACLS drugs (IV lidocaine, atropine, adenosine, etc.), or other IV drugs (Narcan, labetolol, aminophylline, etc.) unless you know how to use them. A basic kit is all you are required to have. This includes all the drugs I have mentioned in this article (Fig. 3). I have deliberately ignored those that are outside a basic emergency kit.

I would recommend every practicing dentist have a Medical Emergencies kit containing the following items, and know how to use them (Table 1).

• Epinephrine (Adrenaline)––is an adrenergic agonist that increases heart rate and force of contraction, and causes vasoconstriction, which in turn, increases blood pressure. It also causes dilatation of the bronchi and smaller airways, and reduces the release of histamine by mast cells. It is used to treat anaphylaxis, hypotension and bronchospasm. It is also a mainstay of Advanced Cardiac Life Support protocols. It is available as a 1:1000 (1 mg/ml) solution in ampules and pre-loaded syringes. Usual dose is 0.3–0.5 ml (depending on severity) given intramuscularly or intravenously. It can be repeated every 10 –20 minutes as needed when given IM. If given intravenously, the dose can be repeated every five minutes as necessary.

• Diphenhydramine (Benadryl)––is used to treat allergic reactions, anaphylaxis, and can be used in asthma attacks when precipitated by exogenous allergens. It is a histamine receptor blocker (H1 receptors). The standard dose is 50 mg IM or IV. This may be repeated once if the reaction is severe. This is usually followed with a 50 mg oral dose every six hours for 24 hours.

• Corticosteroids––are used to treat acute adrenal insufficiency and as adjunctive therapy for allergic reactions and asthma. These drugs promote cell membrane stabilization and inhibit the production of biochemical mediators of inflammation. The standard dose is 100 mg of hydrocortisone or its equivalent (Table 2), given intramuscularly or intravenously.

• Nitroglycerine (Nitro-Stat, Nitrolingual, NitroQuick)––is a coronary and peripheral vasodilator used to relieve the chest pain associated with angina pectoris, and to differentiate between angina and a myocardial infarction. It is available in both a sublingual tablet and a sublingual spray. The standard dose for both delivery systems is 0.4 mg sublingually. It can be repeated at five-minute intervals up to three doses. Blood pressure should be monitored, and the dose should not be repeated if the systolic pressure goes below 100 mm Hg.

• Albuterol or Metaproterenol inhaler (Proventil, Ventolin, Alupent)––is a beta-2 agonist that relaxes bronchial smooth muscle, resulting in dilatation of airways. It indicated for the acute treatment of asthma, or as an adjunct to the treatment of bronchospasm in anaphylaxis. The patient should be given 2 puffs from the inhaler every two minutes as needed, to a maximum of 20 puffs. The first puff should be delivered during a slow, deep inspiration, followed by holding the breath for 10 seconds. This is repeated for the second puff.

• Aspirin––is an inhibitor of the breakdown of cell membranes to prostaglandins and thromboxanes. It was the first of the non-steroidal anti-inflammatory drugs, used as an analgesic and anti-inflammatory. It also is a non-reversible inhibitor of platelet adhesion, and because of this, it is used as a first-line drug for suspected acute myocardial infarction and ischemic stroke. A standard (325 mg) aspirin tablet should be broken in half. One half should be chewed and allowed to be absorbed sublingually, and the other half swallowed.

• Aromatic spirits of ammonia ampules––produce a noxious odor and are used as a respiratory stimulant in syncope. They can also be used to disrupt the respiratory pattern in the hyperventilation syndrome. A single ampule is crushed and waved under the patient’s nose.

• Sugar––is used to treat hypoglycemia. For a mild case in a conscious patient, a sugar-containing drink can be given. For a more severe reaction, a sugar-containing paste is administered sublingually or into the buccal sulcus. Cake icing is as effective as more expensive “medical” dextrose paste. If unconscious, 50–100 cc of 50% dextrose should be given intravenously over 2–3 minutes.

• Eye Wash solution––a variety of sterile, balanced isotonic saline ophthalmologic eye wash solutions are available from your local pharmacy or pharmaceutical supplier. They can be used by irrigating the affected eye with approximately 10–20 ml of solution or by placing the solution in an eyecup and having the patient move their eyeball within the cup.

OXYGEN––The most important emergency drug. It can be used in every office emergency, except hyperventilation syndrome. Oxygen delivered by nasal cannula provides about 4% above room air for every liter/minute flow rate (e.g.: 4 L/min provides 21% + 16%= 37% oxygen). A facemask provides about 60% oxygen at 6 L/min flow rate, with an additional 10% for each additional liter per minute flow rate. Since hypoxia is a powerful respiratory stimulant, over-oxygenation may reduce respiratory drive, requiring ventilatory assistance by the care provider.

Other useful adjuncts that can be part of the office emergency kit include the following:

Airways
An Oropharyngeal airway is used to keep the airway open and free of obstruction by the tongue. They come in a variety of sizes for children and adults. They are placed with the concave surface facing the tongue. They should only be used in an unconscious patient, as placement may induce vomiting in the conscious or semi-conscious patient.

A Nasopharyngeal airway is used in a conscious patient, or when access to the patient’s oral cavity is difficult. It is also less likely to stimulate vomiting in a conscious or semi-conscious patient. These also come in various sizes, for adults and children. A surgical lubricant is recommended to facilitate placement. It is placed in the nasal passage parallel to the direction of the palate. If significant resistance is felt, a smaller airway should be used.

Bag-Valve-Mask Device (Ambu Bag)––is used to provide positive-pressure ventilation to a patient who has inadequate or absent breathing. It can be used with an oral or nasal airway in place. An oxygen source should be connected to the device, however, if not readily available, artificial ventilation should not be delayed. Facemasks come in various sizes to provide a good seal over the nose and mouth.

• Automatic External Defibrillator (AED)––The treatment of sudden cardiac arrest changed dramatically in the late 1990s with the introduction of the Automatic External Defibrillator. The survival rate for out-of-hospital sudden cardiac arrest, which is almost always due to ventricular fibrillation, is poor when defibrillation is delayed beyond five minutes. The AED is a completely portable defibrillator, about the size of a notebook computer (Fig. 4). Unlike with traditional defibrillators, knowledge of Advanced Cardiac Life Support (ACLS) protocols, and ability to recognize various arrhythmias, is not required to operate an AED. In fact, its use is now part of the curriculum for Basic Life Support training. The device automatically analyzes the electrocardiographic rhythm and decides whether defibrillation is indicated. When prompt defibrillation is performed, the chance of survival from a sudden cardiac arrest approaches 90%. These devices cost between $2,000–3,000, and are simple to operate. Given the benefit of this device, with its relative low cost, it is worth investigating having one of these in your office. The life it saves might even be your own.

The following medications have been mentioned in this article, but are not part of the recommended basic emergency kit. They should be used only by practitioners who have advanced training and experience in intravenous sedation and general anesthesia techniques, and are familiar with their pharmacology and appropriate use. They will be mentioned by name only. • Glucagon
• Morphine sulfate
• Benzodiazepines
• Barbiturates
• Intravenous fluids

There are a number of commercially available kits on the market that sell the emergency drugs and supplies in a customized case. They also monitor the expiration date of the contents and replace them as necessary. The prepared kits tend to be more expensive than buying the individual medications from your local supplier. You are basically paying for the convenience of having someone else check the expiration dates, and for that fancy case. In addition, these kits may contain drugs the practitioner will never use. My recommendation is that practitioners assemble and maintain their own kits. This way, you know what is in the kit, and are familiar with all the drugs present. However, some doctors will still prefer to have one less thing to worry about, and leave the maintenance of the emergency kit to an outside vendor––they feel the extra cost is worth the convenience. Each practitioner will need to decide what works best in his or her own practice.

Hopefully, this brief review of the most common medical emergencies to occur in the dental office will stimulate you to do some further reading on the subject. A few useful texts are referenced at the end of this essay. At the very least, I hope it has jogged your memory, so that you will remember where to begin if one of these events occurs in your office. This will also be a useful review for your staff. As I stated at the beginning of Part I, the best way to manage office medical emergencies is to avoid them as much as possible. Be sure to have all your patients update their medical histories annually, and review them before each appointment. Also, use alert stickers for allergies and important medical conditions, so all office staff members who are involved with direct patient care are aware of each patient’s health status. Even if it is not required in your state, all members of the dental office team should be certified in Basic Life Support. If sedation is administered, Advanced Cardiac Life Support training will give you added confidence in managing airway and cardiac emergencies. Hopefully, you will never need the skills acquired from these courses. But, you can never be too prepared for the time when you find yourself facing a medical emergency involving a patient, member of the dental team, friend, neighbor, or a family member.

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
6. Eliastam M, Sternbach GL, Bresler MJ. Manual of Emergency Medicine. Mosby, St. Louis, MO. Fifth edition. 1989.