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Nifedipine in the management of hypertensive emergencies
174
The Journal of Emergency Medicine
travenous aminophylline had significantly more adverse side effects than those receiving placebo. The authors conclude that repeated inhalation of beta-adrenergic agonists alone may be the optimal bronchodilator therapy for the emergency department treatment of acute exacerbations of asthma. [Gerald J. Estep, MD] Editor’s Note: This study examines the shortterm effect of therapy during a three-hour emergency department stay. It does not address the frequency of early readmission or symptoms following discharge for which optimization of serum theophylline levels may be beneficial.
groups nor was there any evidence of toxicity from methylprednisolone. This study demonstrates that the early use of intravenous glucocorticoids in the emergency treatment of acute asthma can help terminate the asthmatic attack and reduce the need for hospitalization. [Gary Neifeld, MD] Editor’s Note: As noted in previous studies, prompt administration of steroids appears to improve the short-term clinical course of patients with acute asthma. The long-term effects of repeated short-term dosing, however, has not been adequately determined.
0 A CONTROLLED TRIAL OF METHYLPREDNISOLONE IN THE EMERGENCY TREATMENT OF ACUTE ASTHMA. Littenberg B, Gluck EH. N Eng/ J Med 1986; 314: 150-152. This randomized double-blind study was designed to assess the value of the early use of methylprednisolone in the treatment of acute asthma in patients not currently taking steroid medication. On admission to the emergency department (ED), 97 patients with acute asthma were asked to subjectively rate their symptoms on a scale of 0 to 3, corresponding to none, mild, moderate, and servere. Objective spirometric measurements of forced vital capacity (FVC) and forced expiratory volume in the first second (FEV,) were also recorded. Measurements were repeated on discharge from the ED, and attempts were made to contact all patients by phone within one week of discharge. All patients were treated as indicated with subcutaneous epinephrine or terbutaline, oxygen, aerosolized metaproterenol, and intravenous aminophylline. Within the first 30 minutes of treatment, each patient was given either 125 mg of intravenous methylprednisolone or placebo. Patients remained in the ED for an average of four hours (range 1 to 12.5 hours). Subjective and spirometric indices were similar on entry into the study in both groups. Twenty-three of 49 patients (47%) of placebo-treated patients required hospital admission as compared with 9 of 48 (19vo) methylprednisolone-treated patients 0, < .003). The steroid group also had significant improvement in their subjective index as compared with the control group; smaller differences were found in FEV, and FVC that were not significant. There was no difference in the frequency of early readmission between the two
q NIFEDIPINE IN THE MANAGEMENT OF HYPERTENSIVE EMERGENCIES. Cohan JA, Checcio LM. AA4 JEmerg Med 1985; 3:524-530. This article reviews the utility of nifedipine in hypertensive emergencies. Included are two case reports of patients with severe hypertension (diastolic blood pressure> 130 mm Hg): one with confusion and one with congestive heart failure, who experienced a prompt reduction in blood pressure with resolution of symptoms after the buccal administration of 10 mg nifedipine. Nifedipine reduces blood pressure by blocking the influx of calcium into vascular smoothmuscle cells, which results in decreased vascular tone. It has been used successfully in patients with hypertensive emergencies and seizures, congestive heart failure, encephalopathy, and cerebrovascular accidents. Unlike clonidine, reserpine, and methyldopa, nifedipine does not cause central nervous system depression that could be confused with a progressive decline in mental status, nor does it require the degree of intensive monitoring required by the administration of nitroprusside, diazoxide, and trimethaphan. The onset of action for buccally or sublingually administered nifedipine is 10 to 15 mintues, with a peak effect at 30 minutes; for orally administered nifedipine the onset of action and peak effect are 30 to 45 minutes and 60 minutes, respectively. The duration of effect is four to six hours regardless of the route of administration. Prior studies have demonstrated a mean arterial pressure reduction of 21.6%. Nifedipine appears to be a safe and effective agent for the management of hypertensive emergencies, particularly in the emergency department setting. [John L. Abt, DO]
175
Abstracts
Editor’s Note: This is an excellent review of the pharmacology and indications for nifedipine in the control of accelerated hypertension. Although the advantages of nifedipine are numerous, it does not offer the minute to minute blood pressure control of nitroprusside, which remains the gold standard in the therapy of hypertensive emergencies.
U INTRAMUSCULAR LIDOCAINE FOR PREVENTION OF LETHAL ARRYTHMIAS IN THE PREHOSPITALIZATION PHASE OF ACUTE MYOCARDIAL INFARCTION. Koster RW, Dunning AJ. N Engl Med 1985; 313:1105-1110. The authors report the results of a randomized, prospective protocol utilizing intramuscular lidocaine in an attempt to prevent dysrhymias in the prehospital phase of acute myocardial infarction. Patients with acute chest pain were randomized to treatment or control groups, with treated patients receiving 400 mg of lidocaine in the deltoid muscle by responding paramedics. Patients with congestive heart failure, heart rate less than 45 beats per minute, and those who had received pretreatment with lidocaine by the referring physician were excluded. Of the 6,024 patients randomized, 32% proved to have acute myocardial infarction by standard serial enzymes and ECG criteria. The mean plasma lidocaine level was 3 pg/mL 11 to 20 minutes after injection in treated patients. Primary ventricular fibrillation within 60 minutes of randomization occurred in 8 treated patients and 17 control patients, a difference that was not statistically significant. In the last 45 minutes of the 60minute observation period, ventricular fibrillation was observed in 12 control patients and 2 treated patients (PC .Ol). The authors postulate that the lack of efficacy of lidocaine in the first 15 minutes after administration may have been due to subtherapeutic lidocaine levels. Ventricular fibrillation was treated promptly by defibrillation, and there was no difference in mortality between control and treatment groups during the observation period. Side effects were rare and did not contribute to mortality. The authors conclude that intramuscular injection of lidoCaine may be of value in patients with a high risk of sudden death within the first few hours of symptom onset, particularly in an out-of-hospital setting where a defibrillator is unavailable. [R. Scott Israel, MD]
Editor’s Note: The authors extend their discussion to suggest that administration of lidoCaine by lay people or by the patients themselves may be of value in the out-of-hospital setting. It should be noted, however, that this study excluded patients with congestive heart failure and those with heart rates less than 45 beats per minute in whom further myocardial depression or suppression of a ventricular escape rhythm might result from lidocaine administration. It remains to be shown that the benefits of lidoCaine outweigh the risks in such an unselected population.
c? EVALUATION AND OTUCOME OF THE DIZZY PATIENT. Madlon-Kay DJ. J Family Prac 1985; 21:109-113. This study is a retrospective review of 121 unselected patients arriving at an emergency department with a chief complaint of dizziness. Of the patients in whom a cause was identified, peripheral vestibular disease accounted for the largest number, consisting of 24% of the total. Diagnoses in this group included labyrinthitis, vestibular neuronitis, benign postitional vertigo, and otitis media. These patients often described nausea, vomiting, and diaphoresis, and nystagmus could frequently be elicited by provocative maneuvers. Infection, anemia, cardiac disease, and other causes accounted for much smaller percentages of diagnoses. In 37% of the patients no cause had been determined at six months of follow-up. History and physical examination provided the most important diagnostic information in 83% of those patients in whom a diagnosis was established. Orthostatic blood pressure determination and maneuvers to test vestibular function were particularly useful. Complete blood count and chest radiography were the most useful routine diagnostic tests. [R. Scott Israel, MD]
0 EVALUATION OF PROGNOSTIC CLASSIFICATIONS FOR PATIENTS WITH SYNCOPE. Eagle KA, Black HR, Cook EF. et al.
Am J Med 1985; 79:455-460.
To evaluate the prognostic classifications for syncope, the authors describe their study of 176 patients arriving at the emergency department with syncope and integrate their data with that from two previously published series. Their
The Journal of Emergency Medicine
travenous aminophylline had significantly more adverse side effects than those receiving placebo. The authors conclude that repeated inhalation of beta-adrenergic agonists alone may be the optimal bronchodilator therapy for the emergency department treatment of acute exacerbations of asthma. [Gerald J. Estep, MD] Editor’s Note: This study examines the shortterm effect of therapy during a three-hour emergency department stay. It does not address the frequency of early readmission or symptoms following discharge for which optimization of serum theophylline levels may be beneficial.
groups nor was there any evidence of toxicity from methylprednisolone. This study demonstrates that the early use of intravenous glucocorticoids in the emergency treatment of acute asthma can help terminate the asthmatic attack and reduce the need for hospitalization. [Gary Neifeld, MD] Editor’s Note: As noted in previous studies, prompt administration of steroids appears to improve the short-term clinical course of patients with acute asthma. The long-term effects of repeated short-term dosing, however, has not been adequately determined.
0 A CONTROLLED TRIAL OF METHYLPREDNISOLONE IN THE EMERGENCY TREATMENT OF ACUTE ASTHMA. Littenberg B, Gluck EH. N Eng/ J Med 1986; 314: 150-152. This randomized double-blind study was designed to assess the value of the early use of methylprednisolone in the treatment of acute asthma in patients not currently taking steroid medication. On admission to the emergency department (ED), 97 patients with acute asthma were asked to subjectively rate their symptoms on a scale of 0 to 3, corresponding to none, mild, moderate, and servere. Objective spirometric measurements of forced vital capacity (FVC) and forced expiratory volume in the first second (FEV,) were also recorded. Measurements were repeated on discharge from the ED, and attempts were made to contact all patients by phone within one week of discharge. All patients were treated as indicated with subcutaneous epinephrine or terbutaline, oxygen, aerosolized metaproterenol, and intravenous aminophylline. Within the first 30 minutes of treatment, each patient was given either 125 mg of intravenous methylprednisolone or placebo. Patients remained in the ED for an average of four hours (range 1 to 12.5 hours). Subjective and spirometric indices were similar on entry into the study in both groups. Twenty-three of 49 patients (47%) of placebo-treated patients required hospital admission as compared with 9 of 48 (19vo) methylprednisolone-treated patients 0, < .003). The steroid group also had significant improvement in their subjective index as compared with the control group; smaller differences were found in FEV, and FVC that were not significant. There was no difference in the frequency of early readmission between the two
q NIFEDIPINE IN THE MANAGEMENT OF HYPERTENSIVE EMERGENCIES. Cohan JA, Checcio LM. AA4 JEmerg Med 1985; 3:524-530. This article reviews the utility of nifedipine in hypertensive emergencies. Included are two case reports of patients with severe hypertension (diastolic blood pressure> 130 mm Hg): one with confusion and one with congestive heart failure, who experienced a prompt reduction in blood pressure with resolution of symptoms after the buccal administration of 10 mg nifedipine. Nifedipine reduces blood pressure by blocking the influx of calcium into vascular smoothmuscle cells, which results in decreased vascular tone. It has been used successfully in patients with hypertensive emergencies and seizures, congestive heart failure, encephalopathy, and cerebrovascular accidents. Unlike clonidine, reserpine, and methyldopa, nifedipine does not cause central nervous system depression that could be confused with a progressive decline in mental status, nor does it require the degree of intensive monitoring required by the administration of nitroprusside, diazoxide, and trimethaphan. The onset of action for buccally or sublingually administered nifedipine is 10 to 15 mintues, with a peak effect at 30 minutes; for orally administered nifedipine the onset of action and peak effect are 30 to 45 minutes and 60 minutes, respectively. The duration of effect is four to six hours regardless of the route of administration. Prior studies have demonstrated a mean arterial pressure reduction of 21.6%. Nifedipine appears to be a safe and effective agent for the management of hypertensive emergencies, particularly in the emergency department setting. [John L. Abt, DO]
175
Abstracts
Editor’s Note: This is an excellent review of the pharmacology and indications for nifedipine in the control of accelerated hypertension. Although the advantages of nifedipine are numerous, it does not offer the minute to minute blood pressure control of nitroprusside, which remains the gold standard in the therapy of hypertensive emergencies.
U INTRAMUSCULAR LIDOCAINE FOR PREVENTION OF LETHAL ARRYTHMIAS IN THE PREHOSPITALIZATION PHASE OF ACUTE MYOCARDIAL INFARCTION. Koster RW, Dunning AJ. N Engl Med 1985; 313:1105-1110. The authors report the results of a randomized, prospective protocol utilizing intramuscular lidocaine in an attempt to prevent dysrhymias in the prehospital phase of acute myocardial infarction. Patients with acute chest pain were randomized to treatment or control groups, with treated patients receiving 400 mg of lidocaine in the deltoid muscle by responding paramedics. Patients with congestive heart failure, heart rate less than 45 beats per minute, and those who had received pretreatment with lidocaine by the referring physician were excluded. Of the 6,024 patients randomized, 32% proved to have acute myocardial infarction by standard serial enzymes and ECG criteria. The mean plasma lidocaine level was 3 pg/mL 11 to 20 minutes after injection in treated patients. Primary ventricular fibrillation within 60 minutes of randomization occurred in 8 treated patients and 17 control patients, a difference that was not statistically significant. In the last 45 minutes of the 60minute observation period, ventricular fibrillation was observed in 12 control patients and 2 treated patients (PC .Ol). The authors postulate that the lack of efficacy of lidocaine in the first 15 minutes after administration may have been due to subtherapeutic lidocaine levels. Ventricular fibrillation was treated promptly by defibrillation, and there was no difference in mortality between control and treatment groups during the observation period. Side effects were rare and did not contribute to mortality. The authors conclude that intramuscular injection of lidoCaine may be of value in patients with a high risk of sudden death within the first few hours of symptom onset, particularly in an out-of-hospital setting where a defibrillator is unavailable. [R. Scott Israel, MD]
Editor’s Note: The authors extend their discussion to suggest that administration of lidoCaine by lay people or by the patients themselves may be of value in the out-of-hospital setting. It should be noted, however, that this study excluded patients with congestive heart failure and those with heart rates less than 45 beats per minute in whom further myocardial depression or suppression of a ventricular escape rhythm might result from lidocaine administration. It remains to be shown that the benefits of lidoCaine outweigh the risks in such an unselected population.
c? EVALUATION AND OTUCOME OF THE DIZZY PATIENT. Madlon-Kay DJ. J Family Prac 1985; 21:109-113. This study is a retrospective review of 121 unselected patients arriving at an emergency department with a chief complaint of dizziness. Of the patients in whom a cause was identified, peripheral vestibular disease accounted for the largest number, consisting of 24% of the total. Diagnoses in this group included labyrinthitis, vestibular neuronitis, benign postitional vertigo, and otitis media. These patients often described nausea, vomiting, and diaphoresis, and nystagmus could frequently be elicited by provocative maneuvers. Infection, anemia, cardiac disease, and other causes accounted for much smaller percentages of diagnoses. In 37% of the patients no cause had been determined at six months of follow-up. History and physical examination provided the most important diagnostic information in 83% of those patients in whom a diagnosis was established. Orthostatic blood pressure determination and maneuvers to test vestibular function were particularly useful. Complete blood count and chest radiography were the most useful routine diagnostic tests. [R. Scott Israel, MD]
0 EVALUATION OF PROGNOSTIC CLASSIFICATIONS FOR PATIENTS WITH SYNCOPE. Eagle KA, Black HR, Cook EF. et al.
Am J Med 1985; 79:455-460.
To evaluate the prognostic classifications for syncope, the authors describe their study of 176 patients arriving at the emergency department with syncope and integrate their data with that from two previously published series. Their