Emergency Drugs

Every dentist can expect to be involved in the diagnosis and treatment of medical emergencies during the course of clinical practice. These emergencies may be directly related to dental therapy, or they may simply occur by chance in the dental environment. Although minor medical emergencies occur predictably, a life-threatening emergency may arise as infrequently as once every 10 years. The potential need for acute medical intervention during dental treatment may be increased for those practitioners treating a high percentage of geriatric, special needs, or medically compromised patients, or those using intravenous sedation or general anesthesia.

Emergency Drugs

Even though many medical emergencies may be properly treated without the use of drugs, every dental office must contain an emergency kit with drugs appropriate to the training of the individual dentist, the patient being treated, and the type of procedures being performed. Obviously, no drug can take the place of a properly trained health professional and support staff in diagnosing and treating emergencies. Nevertheless, the design and/or purchase of an appropriate emergency kit will often play an integral role in dictating the course and outcome of emergency treatment.

Besides determining which drugs should be included in an emergency kit, the dentist must understand that it will be necessary to maintain the knowledge base to use them. In the midst of a medical emergency, with the patient by definition in an acutely abnormal or even critical situation, there is no time to begin reading labels, leafing through emergency texts, or administering drugs as suggested by a brochure in the emergency kit. In addition, there is a significant difference between the theoretical knowledge of how to treat an emergency and being able to put such cognitive skills to practical use. Only constant review and training will keep the dental team sharp. Regular continuing education in medical emergencies and review of pharmacology, certification, and recertification in basic life support (BLS), and in some offices advance cardiac life support (ACLS), coupled with emergency drills are the best methods to prepare for emergencies. Without prompt attention to the ABCs (airway, breathing, circulation) of cardiopulmonary resuscitation, drugs are of little value.

The role of drugs and how much intervention, should be attempted by a dentist during a medical emergency is a controversial issue. If any consequence of dental treatment is foreseeable and results in harm, liability may be imposed . Emergency drugs are generally powerful, rapidly acting compounds. The correct

approach to the use of drugs in any medical emergency should be essentially supportive and conservative. In a review covering the use over a 2-year period of 8500 emergency drug systems purchased by dentists, a 0.75% incidence was reported.

Emergency kits can be either organized by the individual practitioner or purchased commercially. Many dentists are not comfortable deciding and purchasing individual drugs for their emergency kits, and the purchase of high-quality, commercially available emergency drugs kit modified for one's particular needs can provide consistent drug availability (i.e., periodic drug updating).

There is a general tendency to overequip basic dental emergency kits with drugs that are beyond the needs and expertise of many general dentists. As a rule, the drugs placed in an office emergency kits should only include those drugs familiar to the dentist. It is also best to include only one agent for a particular need. The fewer drugs in an emergency kit, the easier it is to know their proper use, especially during an emergency.

Mandatory Emergency Drugs

There are certain drugs that all dentists must keep readily available in the office in fresh supply for immediate administration (See Table 1 below). Dentists must know reflexively when, how, and in what doses to give these specific agents for acutely life-threatening situations.

Oxygen is a primary, if not the primary, emergency drug indicated in any medical emergency where hypoxemia may be present. These emergencies include, but are not limited to, acute disturbances involving the cardiovascular, respiratory, and central nervous systems. In the hypoxemic patient, breathing enriched oxygen elevates the arterial oxygen tension, which in turn improves oxygenation of

peripheral tissues. Because of the steepness of the oxyhemoglobin dissociation curve, a modest increase in oxygen tension can significantly alter hemoglobin saturation in the hypoxemic individual. Hypoxemia leads to anaerobic metabolism and metabolic acidosis, which often adversely affects the efficacy of emergency pharmacologic interventions.

Table 1: Mandatory Emergency Drugs

Drugs Indications Preparations
Oxygen For use in all medical emergencies where  hypoxemia may be present Steel cylinders (green); E tanks, 690 L
Epinephrine Acute allergic reactions Acute asthma (not responding to adrenergic inhaler)
Ampules: 1 mg
Vials: 1 and 30 mg
Syringes: 0.3 and 1 mg
Nitroglycerin Angina pectoris                              Acute myocardial infarction
Tablets (sublingual): 0.15, 0.3, 0.4, and 0.6 mg
Spray: 0.4 mg/actuation

Adapted from:

Holroyd SV, Wynn RL, Requa-Clark, B: Clinical pharmacology in dental practice, ed 4, St. Louis, 1988, The C. V. Mosby Company

Oxygen can be delivered to the spontaneously breathing patient via full face mask, nasal cannulae, or nasal hood. Dental offices should also have the capacity to deliver oxygen via positive-pressure ventilation. Controlled ventilation may be accomplished with the use of a bag-valve-mask device (consisting of a mask, self-inflating bag, and nonrebreathing valve) or with a manually triggered oxygen-powered breathing device (consisting of a mask connected via a valve activated by a lever and high-pressure tubing to the oxygen supply). Each method of providing positive-pressure ventilation requires some practice for effective use. It is difficult with the bag-valve mask device to provide a seal around the nose and mouth while simultaneously ventilating the patient. The oxygen-powered device is easier to use but care must be taken not to inflate the stomach.

Both techniques, however, are preferred over mouth-to-mouth, mouth-to-nose, or mouth-to-mask techniques. Airway adjuncts, such as oropharyngeal and nasopharyngeal airways, endotracheal equipment, laryngeal masks, and the means of establishing an emergency airway via cricothyrotomy and transtracheal ventilation can be useful or even life-saving in the hands of a trained and experienced health professional. Without appropriate training, however, their use may prove deleterious in an acute emergency.

There are absolutely no contraindications to the administration of oxygen in emergency situations. Although oxygen toxicity may occur after prolonged therapy with high concentrations of oxygen, it is not an issue during clinical resuscitation. This statement holds true even for the rare patient whose respiratory drive is dependent on hypoxemia because of chronically elevated carbon dioxide concentrations. If clinically indicated, oxygen should never be withheld during any medical emergency.

Epinephrine The inclusion of epinephrine in a dental office emergency kit is mandatory for the treatment of cardiac arrest and overwhelming anaphylaxis. However, it must be emphasized that these extreme conditions are the only situations that would require its use in the dental office emergency. There are a few clinicians who maintain the mistaken belief that epinephrine is the drug of choice in shock or shocklike states. There are three principal reasons for disputing this belief.

First, in shock from almost any cause there is decreased venous return to the heart because of peripheral venous pooling. Because the peripheral action of epinephrine is primarily on the arterial side, there is little gain in promoting peripheral vasoconstrictions, which is already present because of the massive release of endogenous catecholamines (epinephrine and norepinephrine). At this point administration of epinephrine may further decrease venous return and tissue perfusion. Second, a possible deleterious effect is an increase in selective ischemia that takes place in certain viscera such as the kidney. Here, as in peripheral vessels, the blood supply is constricted in a compensatory effort to increase blood flow to the more vital brain and heart tissues. Perpetuation of this condition could be undesirable. Third, the possible precipitation of ventricular fibrillation in the ischemic and irritable myocardium is an important factor. This could be especially disastrous in the dental office where defibrillation equipment is usually not available. In early treatment of shock states the patient will benefit more from measures aimed at correction of the primary cause such as hypovolemia rather than misdirected attempts at pharmacologic correction.

Desirable properties of this agent include a rapid onset of action; potent action as a bronchial smooth muscle dilator (beta2 properties); antihistaminic actions; vasopressor actions; and its actions on the heart, which include an increased heart rate (21%), increased systolic blood pressure (5%), decreased diastolic blood pressure (14%), increased cardiac output (51%), and increased coronary blood flow. Undesirable actions include its tendency to predispose the heart to dysrhythmias and its relatively short duration of action.

Epinephrine is an important drug during cardiac arrest because no other drug is capable of maintaining coronary artery blood flow while CPR is in progress, which is essential for preserving the chances of survival from cardiac arrest. Epinephrine also preserves blood flow to the brain. In the absence of drug therapy, cerebral blood flow during CPR is minimal; most blood enters the common carotid artery and flows into the external carotid branch, not the internal carotid artery. Following administration of a drug with a-adrenergic properties, such as epinephrine, cerebral blood flow is significantly increased.

For the effective treatment of acute allergic reactions, epinephrine must be administered as soon as the condition is diagnosed. The drug can be injected subcutaneously 0.3 to 0.5 mL of a 1:1000 solution, or intramuscularly (for a more serious emergency), 0.4 to 0.6 mL of the same solution. The intravenous route is also possible, but it may induce or exacerbate ventricular ectopy, especially in patient receiving digitalis. Epinephrine may also be instilled directly into the tracheobronchial tree via an endotracheal tube with good results.

Because of its profound bronchodilating effects, epinephrine is also indicated for the treatment of acute asthmatic attacks unrelieved by b2-adrenergic sprays or aerosols.

Side effects, contraindications, and precautions: Tachydysrhythmias, both supraventricular and ventricular, may develop. Epinephrine should be used with caution in pregnant women because it decreases placental blood flow and may induce premature labor. When used, all vital signs must be monitored frequently. In the setting of the dental practice, epinephrine will usually be considered for administration in situations that are considered to be life threatening (anaphylaxis, cardiac arrest). Under such situations the advantages of administering this agent clearly outweigh any risk. In effect there are no contraindications to the administration of epinephrine under these conditions.

Antihistamines will be of value in the treatment of the delayed allergic response and in the definitive management of the acute allergic reaction (administered after epinephrine has terminated the acute life-threatening phase of the reaction). Antihistamines act as competitive antagonists of histamine. They do not prevent the release of histamine from cells in response to injury, drugs, or antigens, but do prevent access of histamine to its receptor site in the cell and thereby block the response of the effector cell to histamine. Thus, antihistamines are more potent in preventing the actions of histamine than in reversing these actions once they develop.

Nitroglycerin Vasodilators are used in the immediate management of chest pain (such as may occur with angina pectoris or acute myocardial infarction). Two varieties of vasodilator are available: nitroglycerin (TNG) as a tablet and a spray, and an inhalant, amyl nitrite. A patient with a history of angina pectoris will usually carry a supply of nitroglycerin. Tablets remain the most popular form of TNG, although most patients prefer the translingual spray once they have used it.

During dental care a patient's nitroglycerin source should be readily accessible. Placed sublingually or sprayed onto the lingual soft tissues, nitroglycerin acts in 1 to 2 minutes. A patient's drug should be used if at all possible, but if it is not available or is ineffective, the 0.4-mg dosage form should be available in the emergency kit. The shelf life of TNG tablets once exposed to air is quite short (about 6 weeks). This is especially true when the container is not adequately sealed or the tablets are stored in a pill box. In these cases the active nitroglycerin vaporizes, leaving behind an inert filler. This is not normally a problem with patients most of whom will use a bottle of tablets in 4 to 6 weeks. Inactivation of the TNG is more likely to occur in the dental office supply where its use is extremely sporadic. Nitroglycerin tablets placed sublingually usually taste bitter and sting. Suspect that the drug has become ineffective if the bitter taste is absent.

Amyl nitrite, another vasodilator, is available for use as an inhalant. It is supplied in a yellow vaporole or a gray cardboard vaporole with yellow printing in a dose of 0.3 mL, which when crushed between one's finger and held under the victim's nose will act in about 10 seconds to produce a profound vasodilation. The duration of action of amyl nitrite is shorter than that of TNG; however, the shelf life of the vaporole is considerably longer. Side effects occur with all vasodilators but they are more significant with amyl nitrite.

Side effects, contraindications, and precautions: Side effects of nitroglycerin include a transient pulsating headache, facial flushing, and a degree of hypotension (noted especially if the patient is in an upright position). Because of its mild hypotensive actions, nitroglycerin is contraindicated in patients who are hypotensive, but may be used with some degree of effectiveness in the management of acute hypertensive episodes. Side effects of amyl nitrite are similar to but more intense than those of nitroglycerin. These include facial flushing, pounding pulse, dizziness, intense headache, and hypotension. Amyl nitrite should not be administered to patients who are in an upright position because the patient may feel dizzy and suffer a fall.

Primary Support Drugs

Primary support drugs are helpful for treating medical emergencies that are usually not acutely life-threatening. Although it is not mandatory that every dentist include these drugs in the emergency kit, they are all useful, particularly in situations where the dentist is familiar with their use and where emergency medical services may not be immediately available.

Secondary Injectable Drugs: Seven drug categories are included in this level:

1. Anticonvulsant

2. Analgesic

3. Vasopressor

4. Antihypoglycemic

5. Corticosteroid

6. Antihypertensive

7. Anticholinergic

Noninjectable drugs: There are three noninjectable drugs that are considered at this level:

1. Respiratory stimulant

2. Antihypoglycemic

3. Bronchodilator

Table 2: Emergency Support Drugs

Category Generic Proprietary Alternative
 

Injectables

     
Anticonvulsant Midazolam Versed Diazepam
Analgesic   Morphine   Meperidine
Vasopressor Methoxamine Vasoxyl Phenylephrine
Antihypoglycemic 50% Dextrose sol.   Glucagon
Corticosteroid   Hydrocortisone Solu-Cortef sodium succinate   Dexamethasone
Antihypertensive  Labetalol HCl   Normodyne
Anticholinergic Atropine    
 

Noninjectables

     
Respiratory stimulant Aromatic Ammonia    
Antihypoglycemic Carbohydrate            Decorative icing Many  
Bronchodilator Albuterol Ventolin, Proventil Metaproterenol
Antihypertensive Nifedipine Procardia  

Adapted from: Malamed SF: Sedation: a guide to patient management, ed 2, St. Louis, 1991, Mosby-Year Book.

Anticonvulsant Seizures that may require acute medical intervention may be associated with epilepsy, hyperventilation episodes, cerebrovascular accidents, hypoglycemic reactions, or vasodepressor syncope. Local anesthetic overdoses or accidental intravascular injection may also require the administration of an anticonvulsant. Current management of a seizure that interferes with ventilation or persists for longer than 5 minutes includes the use of an intravenous benzodiazepine such as diazepam or midazolam.

With its introduction, diazepam became the preferred anticonvulsant. Because seizure disorders are characterized by a stimulation of the central nervous and cardiorespiratory and cardiovascular systems, followed by a period of depression of these same systems, drugs that depress the systems at therapeutic does are more likely to produce postseizure complications. When barbiturates are administered to terminate seizure activity, the degree of postseizure depression is accentuated and its duration prolonged because of the pharmcologic action of the barbiturate.

If the doctor is not adapt at recognizing and managing this situation, the patient may be worse off after the seizure than during it. The benzodiazepines, unlike barbiturates, will usually terminate seizure activity without the pronounced depression of the respiratory and cardiovascular systems.

Analgesic medications will be useful during emergency situations in which acute pain or anxiety is present. In most instances the presence of pain or anxiety will cause an increase in the workload of the heart (and an increased myocardial oxygen requirement) that may prove detrimental to the well-being of the patient. Two such circumstances are acute myocardial infarction and congestive heart failure. The choice of analgesic drugs includes the narcotic agonists morphine sulfate and meperidine (Demerol).

Side effects, contraindications, and precautions: Narcotic agonists are potent CNS and respiratory depressants. Vigilant monitoring of vital signs is mandatory whenever these agents are used. Use of narcotic agonists is contraindicated in victims of head injury and multiple trauma; they should be used with care in persons with compromised respiratory function.

Vasopressor In most emergency situations in which a vasopressor is indicated in the dental office, an agent such as epinephrine will not be the drug of choice. Epinephrine will be used primarily in the management of acute allergic reactions and is rarely employed in cases of clinically mild to moderate hypotension. One reason for this is that epinephrine elicits an extreme antihypotensive response. In addition to an increase in blood pressure, epinephrine causes an increase in the workload of the heart through its effect on heart rate and cardiac contraction; it also increases the irritability of the myocardium by sensitizing it to dysrhythmias.

Vasopressors such as methoxamine (Vasoxyl) and phenylephrine (Neo-Synephrine) are drugs that produce moderate blood pressure elevations through peripheral vasoconstriction.

Methoxamine is a clinically useful vasopressor with sustained action and little effect on the myocardium or central nervous system. Its vasopressor action is associated with a marked increase in peripheral resistance and no increase in cardiac output. A compensatory bradycardia accompanies the rise in blood pressure produced by methoxamine. The onset of the pressor action is almost immediate following IV administration and may persist for up to 60 minutes. After IM injection the response occurs within 15 minutes and persists for 90 minutes.

Phenylephrine acts in a similar fashion, with a 5-mg IM dose causing a 30-mm Hg elevation of systolic blood pressure and a 20-mm Hg elevation of diastolic blood pressure, with the response persisting for 50 minutes. As with methoxamine, a pronounced and persistent bradycardia will be noted (average decline in heart rate from 70 to 44 beats per minute).

Antihypoglycemic Glucose preparations are used to treat hypoglycemia that results either from fasting or insulin use in a patient with diabetes mellitus. If the patient is conscious, oral carbohydrates such as chocolate bar, cake icing, or cola drink will act rapidly to restore circulating blood sugar. On the other hand, if the patient is unconscious and acute hypoglycemia is suspected, intravenous administration of 50% dextrose solution is the treatment of choice.

Corticosteroids will be administered in the management of an acute allergic reaction, but only after the acute phase has been brought under control through the use of basic life support, epinephrine, and antihistamines. The primary value of the corticosteroids is in the prevention of recurrent episodes of anaphylaxis. Corticosteroids are also important in the management of acute adrenal insufficiency.

The onset of intravenous corticosteroids, such as hydrocortisone sodium succinate, is delayed, but the drugs can be useful in halting the progression of a major allergic or anaphylactoid reaction. There is also the potential for encountering what appears initially to be a syncopal episode but is in reality the more serious problem of acute adrenal insufficiency in a patient chronically taking systemic corticosteroids to treat a medical condition. For this life-threatening emergency, only the prompt diagnosis and infusion of corticosteroids will be curative.

Hydrocortisone sodium succinate is considered the drug of choice for the dental emergency kit. Corticosteroids are considered second-line drugs primarily because of their slow onset of action.

Antihypertensive The need to administer drugs to decrease excessive elevations in blood pressure is extremely uncommon. First, the incidence of extreme acute blood pressure elevation is quite rare and, second, there are other means of decreasing blood pressure without resorting to parenteral antihypertensive drugs.

Emergency Drugs
Oral drugs, such as nifedipine or nitroglycerin, may be administered in most situations to provide a minor depression of blood pressure. The inclusion of a drug in this category is in response to state requirements for general anesthesia permits (and in a few states for parenteral sedation, too).

Anticholinergic Atropine, a parasympathetic blocking agent, is recommended for the management of symptomatic bradycardia (adult heart rate of <60 beats per minute). By enhancing discharge from the sinoatrial (SA) node, atropine may provoke tachycardia (adult heart rate>100 beats per minute). Atropine will be of benefit in situations in which the patient has an overload of parasympathetic activity on the heart. Extremely fearful patients are likely candidates for this response.

Atropine is also considered an essential drug in advanced cardiac life support (ACLS), in which it is employed in the management of bradydysrhythmias (hemodynamically significant heart block and asystole).

Side effects, contraindications, and precautions: Large doses of atropine (>2.0 mg) may produce clinical signs of overdosage, including: hot, dry skin; headache; blurred near vision; dryness of the mouth and throat; disorientation; and hallucination. Administration of atropine is contraindicated in patients with glaucoma or prostatic hypertrophy. However, in life-threatening situations the benefits of atropine administration usually outweigh the possible risks.

Respiratory stimulant After oxygen, aromatic ammonia is the most commonly used drug in the emergency situation. It is available in a silver-gray vaporole, which is crushed and placed under the victim's nose until respiratory stimulation is effected. Aromatic ammonia has a noxious odor and acts by irritating the mucous membrane of the upper respiratory tract, thereby stimulating the respiratory and vasomotor centers of the medulla; this in turn increases respiration and blood pressure. Movement of the arms and legs often occurs in response to inhalation of ammonia. This too acts to increase the return of blood from the periphery and aids in raising blood pressure, especially if the patient has been positioned properly.

Side effects, contraindications, and precautions: Ammonia should be employed with caution in persons with chronic obstructive pulmonary disease (COPD) or asthma because its irritating effects on the mucous membranes of the upper respiratory tract may precipitate bronchospasm.

Antihypoglycemic agents will be useful in the management of hypoglycemic reactions occurring in patients with diabetes mellitus or in the nondiabetic patient with hypoglycemia (low blood sugar). The diabetic patient will usually carry a ready source of carbohydrate such as a candy bar or hard candy. Such items should also be available in the dental office for use in the conscious patient with hypoglycemia.

Bronchodilator Asthmatic patients and patients with allergic reactions manifested primarily by respiratory difficulty will require the use of bronchodilator drugs. Although epinephrine remains the drug of choice in the management of bronchospasm, its wide ranging actions on systems other than the respiratory tract has resulted in the introduction of newer, more specific agents known as b2-adrenergic agonists. These agents, of which albuterol is an example, have specific bronchial smooth muscle-relaxing properties (b2) with little or no stimulatory effect on the cardiovascular and gastrointestinal systems (b1) . In the dental situation in which the patient's true cardiovascular status may be unknown, b2 agonists appear more attractive for management of the acute asthmatic episode than agents that have both b1 and b2 agonist properties, such as epinephrine and isoproterenol.

Bronchodilators must be administered precisely as directed. One to two inhalations every 4 to 6 hours is the recommended dosage for albuterol. Nebulized epinephrine (e.g., Primatene-Mist ) should be administered one to two inhalations per hour. In situations in which these nebulized agents fail to terminate the attack, other bronchodilators (e.g., epinephrine, aminophylline, isoproterenol) must be administered parenterally (intramuscularly or subcutaneously).

Side effects, contraindications, and precautions: Albuterol, like other b2 agonists, may have a clinically significant cardiac effect in some patients. This response is less likely to develop with albuterol than with other bronchodilators, thus its selection for the emergency kit. Metaproterenol, epinephrine, and isoproterenol mistometers are more likely to produce cardiovascular side effects, including tachycardia and ventricular dysrhythmias.

Drugs For Advanced Cardiac Life Support

ACLS is the standard of care for comprehensive resuscitation by health care providers with advanced skills and training. Training in ACLS is necessary for those dentists administering deep sedation or general anesthesia and is sometimes required by state law for providers of parenteral conscious sedation. State regulations should be consulted to determine which of the drugs described here must be available when sedation or anesthesia is administered.

Table 3: Advanced Cardiac Life Support Drugs

Drug Indication
 

Antiarrhythmics

 
Lidocaine Ventricular tachycardia, pulseless, ventricular tachycardia, or ventricular fibrillation
Procainamide Ventricular tachycardia, pulseless ventricular tachycardia or ventricular fibrillation
Bretylium Ventricular tachycardia, pulseless ventricular tachycardia or ventricular fibrillation
Verapamil, diltiazem Atrial flutter or atrial fibrillation, paroxysmal supraventricular tachycardia
Adenosine Paroxysmal supraventricular tachycardia
Atropine Bradycardia, asystole, first-degree and Mobitz type I atrioventricular block, Mobitz type II and third-degree block
Magnesium Torsades de pointes, ventricular fibrillation
blockers (e.g., propranolol) Atrial flutter or atrial fibrillation, refractory ventricular tachycardia or ventricular fibrillation
 

Inotropes

 
Epinephrine Ventricular fibrillation, asystole, pulseless, electrical activity, bradycardia
Norepinephrine Refractory hypotension
Dopamine Bradycardia, hypotension
Dobutamine Congestive heart failure
Isoproterenol Refractory bradycardia
Digitalis Atrial flutter, fibrillation
Amrinone Refractory congestive heart failure
 

Vasodilators/Antihypertensives

 
Nitroprusside Hypertension, acute heart failure
Nitroglycerin Hypertension, acte heart failure, anginal pain
 

Others

 
Sodium bicarbonate Hyperkalemia, metabolic acidosis with bicarbonate loss, hypoxic lactic acidosis
Furosemide Acute pulmonary edema
Morphine Acute pulmonary edema, pain and anxiety
Thrombolytic agents (e.g., anistreplase) Acute myocardial thrombosis

Adapted From: Holroyd SV, Wynn RL, Requa-Clark, B: Clinical pharmacology in dental practice, ed 4, St. Louis, 1988, The C. V. Mosby Company

Supplementary Drugs

Supplementary drugs are additional emergency drugs that must be available when certain sedative or anesthetic drugs are administered. They include drugs that are used to reverse untoward effects of anesthetics and others that are used to treat specific medical conditions that may occur during anesthesia.

Categories of antidotal drugs include:

1. Narcotic antagonist

2. Benzodiazepine antagonist

3. Antiemergence delirium drug

4. Vasodilator

 

Table 4: Antidotal Drugs

Category Generic Proprietary Alternative
Narcotic antagonist Naloxone Narcan Nalbuphine
Benzodiazepine antagonist Flumazenil Mazicon  
Antiemergence delirium Physostigmine Antilirium  
Vasodilator Procaine Novocain  

Adapted From: Malamed SF: Sedation: a guide to patient management, ed 2, St. Louis, 1991, Mosby-Year Book.

Narcotic antagonist Naloxone is a specific opioid antagonist that reverses opioid-induced respirator depression. It is mandatory in practices where parenteral opioids are administered. Naloxone will also reverse other properties of narcotics, namely analgesia, and sedation. This action is not entirely innocuous because if narcotics have been employed for postsurgical analgesia naloxone administration will antagonize this effect and leave the patient with unmanaged postsurgical pain.

Side effects, contraindications, and precautions: When administered intravenously or endotracheally, the duration of naloxone is but 30 minutes. A recurrence of respiratory depression may be observed if the narcotic employed is of longer duration (e.g., morphine). It is common for a second dose of naloxone to be administered intramuscularly following the intravenous dose. Though slower in onset, the duration of therapeutic action of IM naloxone is considerably longer than IV administration. This regimen will minimize the possibility of a recurrence of respiratory depression.

Benzodiazepine antagonist Although the benzodiazepines have been described as the most nearly ideal agents for anxiety control and sedation, there are still a number of adverse reactions associated with their administration. Emergence delirium, excessive duration of sedation, and possible (though unlikely in most instances) respiratory depression are but a few side effects. The availability of a specific antagonistic agent for benzodiazepines adds another degree of safety to intravenous and, to a lesser extent, intramuscular sedation. Flumazenil has been demonstrated to produce a rapid reversal of sedation and improve a patient's ability to comprehend and obey commands.

Flumazenil is recommended whenever benzodiazepines such as diazepam, midazolam, or lorazepam are administered parenterally.

Antiemergence delirium Several drugs that are commonly employed parenterally to induce sedation have the ability to produce what is known as emergence delirium. Scopolamine and the benzodiazepines, diazepam and midazolam, are most likely to produce this phenomenon in which the patient appears to lose contact with reality. Physostigmine (Antilirium), a reversible cholinesterase with the ability to cross the blood-brain barrier, has become the drug of choice in the management of emergence delirium.

Vasodilator A local anesthetic that also possesses significant vasodilating properties is recommended for inclusion in the emergency kit whenever IM or IV drugs are employed. Indications for the use of this drug are extravascular injection of an irritating chemical and accidental intraarterial administration of a drug. In both instances the problem is that of compromised circulation in either a localized area (extravascular administration) or a limb (intraarterial administration).

Procaine possesses excellent vasodilating properties along with its pain-relieving actions, both of which make this drug ideal for administration in the aforementioned situations.

Sources:

Holroyd SV, Wynn RL, Requa-Clark, B: Clinical pharmacology in dental practice, ed 4, St. Louis, 1988, The C. V. Mosby Company

Malamed SF: Sedation: a guide to patient management, ed 2, St. Louis, 1991, Mosby-Year Book.

 

Table 5: Emergency Drug Kit

Drug Indications Adult Dosage and Route of Administration
Epinephrine (Adrenalin)-1:1000 anaphylaxis, cardiac arrest 0.5 ml intravenously
Methylprednisolone sodium succinate (Solu-Medrol)-125 mg Monovile cardiac arrest, anaphylaxis, acute adrenocortical insufficiency 125 mg intravenously, given slowly
Sodium bicarbonate–7.5% cardiac arrest 1 mEq/kg intravenously initially, then half this every 10 minutes
Diphenhydramine (Benadryl) 10 mg/ml acute allergic reaction, extrapyramidal reaction to phenothiazine 5 ml intravenously
Aromatic spirits of ammonia-           crush ampules syncope one ampule, by inhalation
Glyceryl trinitrate–0.6 mg tablet angina pectoris one tablet sublingually
Morphine sulfate–15mg/ml myocardial infarction 1 ml subcutaneously or intravenously
Phenylephrine hydrochloride (Neo-Synephrine Hydrochloride) – 1:500 toxic reaction to local anesthetic 1 to 2 ml intravenously
Dextrose in water–5% hypovolemia, IV route for drug administration 1000 ml IV drip
Diazepam– 5 mg/ml severe or prolonged convulsion as in toxic reaction to local anesthetic 1 to 8 ml intravenously (titrated)
Naloxone hydrochloride(Narcan)       –0.4 mg/ml narcotic depression 1 ml intravenously or intramuscularly
Isoproterenol hydrochloride aerosol–0.25% bronchospasm one or two inhalations
Physostigmine salicylate – 1mg/ml CNS depression following diazepam administration 0.5 to 2 ml intravenously (slow titration)
Atropine sulphate–0.1 mg/ml bradycardia with hypotension 0.5 - 1.0 mg IV

Adapted From: Holroyd SV, Wynn RL, Requa-Clark, B: Clinical pharmacology in dental practice, ed 4, St. Louis, 1988, The C. V. Mosby Company

 

References

1. American Heart Association and National Academy of Sciences: National Research Council: Standards for cardiopulmonary resuscitation (CPR) and emergency cardiac care (ECG), JAMA 255:2905, 1986.

2. American Heart Association: Textbook of advanced cardiac life support, Dallas, 1987, American Heart Association.

3. Barsan WG, Jastremski MS, Syverud SA, eds: Emergency drug therapy, Philadelphia, 1991, WB Saunders.

4. Council on Dental Therapeutics: Emergency kits. J Am Dent Assoc 87:909, 1973.

5. Curriculum guidelines for management of medical emergencies in dental education, J Dent Educ 54:337-338, 1990.

6. Davenport HT: Anesthesia in the elderly, New York, 1986, Elsevier Science.

7. Guidelines for cardiopulmonary resuscitation and emergency cardiac care. Emergency Cardiac Care Committee and Subcommittees. American Heart Association. Adult advanced cardiac life support, JAMA 268:2199-2241, 1992.

8. Guidelines for teaching the comprehensive control of pain and anxiety in dental education, Chicago, 1989, American Dental Association.

9. Hasegawa EA: The endotracheal use of emergency drugs, Heart Lung 15:60-63, 1986.

10.Healthfirst Corporation: Emergency medicine videotape, Seattle, 1991.

11. Lipp M, et al: Management of an emergency: to be prepared for the unwanted event, Anesth Pain Control Dent 2:90-102, 1992.

12. Malamed SF: Sedation: a guide to patient management, ed 2, St. Louis, 1991, Mosby-Year Book.

13. McCarthy FM, ed: Medical emergencies in dentistry, Philadelphia, 1982, WB Saunders.

14. Miller CS, et al: Documenting medication use in adult dental patients: 1987-1991, J Am Dent Assoc 123: 40-48, 1992.

15. Moore PA: Review of medical emergencies in dentistry: staff training and prevention. Part 1. Gen Dent 36:14-17, 1988.

Emergency Drugs
16. Munson ES, Wagman IH: Diazepam treatment of local anesthetic-induced seizures, Anesthesiology 37:523-528-1972.

17. Morrow GT: Designing a drug kit, Dent Clin North Amer 26 (1): 21-33, 1982.

18. Newhouse MT, Dolovich MB: Control of asthma by aerosols, N Engl J Med 315:870-874, 1986.

19. Otto CS, Yakaitis RW: The role of epinephrine in CPR: a reappraisal, Ann Emerg Med 13:840-843, 1984.

20. Paradis NA, Koscove EM: Epinephrine in cardiac arrest: a critical review, Ann Emerg Med 19:1288-1301, 1990.

21. Patterson NA, Koscove EM: Allergic reactions to drugs and biologic agents, JAMA 248:2637-2645, 1982.

22. Phero JC: Maintaining preparedness for the life-threatening office medical emergency, Dent Econ 81:47-50, 1991.