A comparison of lorazepam, diazepam, and placebo for the treatment of out-of-hospital status epilepticus.

BACKGROUND: It is uncertain whether the administration of benzodiazepines by paramedics is an effective and safe treatment for out-of-hospital status epilepticus. METHODS: We conducted a randomized, double-blind trial to evaluate intravenous benzodiazepines administered by paramedics for the treatment of out-of-hospital status epilepticus. Adults with prolonged (lasting five minutes or more) or repetitive generalized convulsive seizures received intravenous diazepam (5 mg), lorazepam (2 mg), or placebo. An identical second injection was given if needed. RESULTS: Of the 205 patients enrolled, 66 received lorazepam, 68 received diazepam, and 71 received placebo. Status epilepticus had been terminated on arrival at the emergency department in more patients treated with lorazepam (59.1 percent) or diazepam (42.6 percent) than patients given placebo (21.1 percent) (P=0.001). After adjustment for covariates, the odds ratio for termination of status epilepticus by the time of arrival in the lorazepam group as compared with the placebo group was 4.8 (95 percent confidence interval, 1.9 to 13.0). The odds ratio was 1.9 (95 percent confidence interval, 0.8 to 4.4) in the lorazepam group as compared with the diazepam group and 2.3 (95 percent confidence interval, 1.0 to 5.9) in the diazepam group as compared with the placebo group. The rates of respiratory or circulatory complications (indicated by bag valve-mask ventilation or an attempt at intubation, hypotension, or cardiac dysrhythmia) after the study treatment was administered were 10.6 percent for the lorazepam group, 10.3 percent for the diazepam group, and 22.5 percent for the placebo group (P=0.08). CONCLUSIONS: Benzodiazepines are safe and effective when administered by paramedics for out-of-hospital status epilepticus in adults. Lorazepam is likely to be a better therapy than diazepam.

Prehospital stability of diazepam and lorazepam.

Injectable benzodiazepines are commonly stocked on ambulances for use by paramedics. We evaluated the stability of lorazepam and diazepam as a function of storage temperature. Diazepam (5 mg/mL) and lorazepam (2 mg/mL) injectable solutions were stored for up to 210 days in clear glass syringes at three conditions: 4 degrees C to 10 degrees C (refrigerated); 15 degrees C to 30 degrees C (on-ambulance ambient temperature); and 37 degrees C (oven-heated). High-performance liquid chromatography (HPLC) analyses of syringe contents were performed at 30-day intervals. After 210 days, the reduction in diazepam concentration was 7% refrigerated, 15% at ambient temperature, and 25% at 37 degrees C. The reduction in lorazepam concentration was 0% refrigerated, 10% at ambient temperature, and 75% at 37 degrees C. Whereas diazepam retained 90% of its original concentration for 30 days of on-ambulance storage, lorazepam retained 90% of its original concentration for 150 days. The decrease in lorazepam concentration correlated with an increase in the maximum ambient temperature in San Francisco. These results suggest that diazepam and lorazepam can be stored on ambulances. When ambient storage temperatures are 30 degrees C or less, ambulances carrying lorazepam and diazepam should be restocked every 30 to 60 days. When drug storage temperatures exceed 30 degrees C, more frequent stocking or refrigeration is required.

Emergency medical services dispatcher identification of stroke and transient ischemic attack.

OBJECTIVE: Certain forms of stroke can be treated if access to medical care is expeditious. Since many stroke victims first enter medical care through emergency medical services (EMS) access, minimizing delays in the EMS system may translate to improved neurologic outcome. Because EMS dispatchers determine the response priority for these calls, dispatchers should be able to recognize the signs and symptoms of stroke based on their brief phone interviews. The authors studied the abilities of dispatchers in a major urban area to correctly identify stroke and transient ischemic attack (TIA) in victims who access 911 and describe what is communicated in the 911 call. METHODS: A retrospective review was conducted of the medical records of patients treated for stroke or TIA at two urban hospitals during 1996. The tape-recorded 911 calls from patients using EMS were transcribed and analyzed. Information regarding dispatcher classification and triage of these calls was collected and described. RESULT: The records of 182 patients with acute stroke or TIA were reviewed. Fifty-three percent of patients used EMS. Dispatchers coded 31% of their 911 calls as stroke. The word "stroke" was used without prompting by 51% of callers, yet fewer than half of these calls were coded as stroke by dispatchers. Many callers reported symptoms characteristic of stroke, including impaired communication (36%), weakness (30%), and decreased ability to stand or walk (25%). Only 41% of ambulances were sent at high priority. CONCLUSION: People who activate EMS for stroke frequently use the word "stroke" and/or describe symptoms compatible with stroke in their calls. EMS dispatch protocols should be sensitive for these symptoms to ensure more accurate and timely ambulance dispatch.

Improved paramedic sensitivity in identifying stroke victims in the prehospital setting.

OBJECTIVE: The authors have previously shown that San Francisco paramedics without specific training in stroke recognition identified acute stroke victims with a 61% sensitivity and a 77% positive predictive value (PPV). The authors implemented an educational program on stroke to improve paramedic accuracy in stroke recognition. METHODS: Twenty-two paramedics volunteered to attend a four-hour seminar about stroke and then were followed prospectively for six months. All encounters with adult patients who were evaluated by both trained and untrained paramedics and were transported to two university hospitals were reviewed. Subjects were identified by paramedic assessment as stroke/transient ischemic attack (TIA) and/or final hospital discharge diagnosis of stroke/TIA after detailed chart review. Sensitivity and PPV for paramedic identification of stroke were calculated. RESULTS: During the prospective six-month phase, 84 confirmed stroke patients were transported to the target hospitals. Of the 32 who were transported by trained paramedics, all but three were identified as having stroke/TIA, resulting in a sensitivity of 91%. This is significantly higher than the 61% previously found (p=0.01). Nontrained paramedics also increased their sensitivity to 90%. Thirty-eight false-positive patients were identified, resulting in PPVs of 64% for trained paramedics and 69% for all other paramedics. CONCLUSIONS: Institution of an educational stroke program was associated with a significant increase in sensitivity in stroke identification by the paramedics; however, educational influences outside this training program may have contributed to the increased sensitivity. Better education for paramedics, combined with rapid response to stroke victims once identified, may result in improved care for victims of acute stroke.

Accuracy of paramedic identification of stroke and transient ischemic attack in the field.

PURPOSE: To determine the accuracy of acute stroke identification by paramedics in an urban emergency medical services system. METHODS: Retrospective chart review of all patient encounters by paramedics resulting in transport to two university hospitals during a six-month period. Subjects were identified by paramedic coding of stroke/transient ischemic attach (TIA) or final hospital discharge ICD-9 diagnosis of acute stroke and TIA. The sensitivity and positive predictive value for paramedic identification of stroke were calculated, and the time intervals from symptom onset to various points along the patients' prehospital and hospital courses were identified. RESULTS: Ninety-six patients were identified, of whom 81 met the diagnosis of acute stroke or TIA. Paramedics identified 49 of these 81 patients (sensitivity 61%). Fifteen patients were identified by paramedics as having a stroke when the patient ultimately had a different diagnosis (positive predictive value 77%) Patients or their families waited on average 2.5 +/- 3.6 (SD) hours before accessing 911, and a mean of 5.1 +/- 4.0 (SD) hours elapsed from symptom onset until head imaging studies were obtained. CONCLUSION: Paramedics in San Francisco County were correct three-fourths of the time when their documentation listed patients as having stroke/TIA. However, they did not identify 39% of stroke victims, a patient population who may benefit from urgent therapy. A substantial period elapses before stroke victims access 911. This highlights the need to develop an educational program for the community at risk for stroke, and another for paramedics directed toward more accurate identification of acute stroke victims.