Abstracts

Rationale: Benzodiazepines (including lorazepam) are the first line treatment for acute convulsive seizures. However, the guidelines on when lorazepam should be given are not clear. The guidelines specify early administration of lorazepam for status epilepticus. However, this is misconceived by many for early administration of lorazepam for acute convulsive seizures. Unfortunately, according to the pathophysiological events taking place during a convulsive seizure, this might be incorrect practice. In literature, early benzodiazepine administration was found helpful to suppress the GABA receptor before its internalization. However, in the first 5 minutes of a seizure, this job is usually achieved by internal GABA release in the brain. Administering lorazepam in this period is usually distributed peripherally more than centrally due to the intact blood brain barrier at that time. Thus theoretically, benzodiazepines would suppress the overstimulated autonomic response rather than the seizure itself leading to vital instability Our study aims to prove clinically that early administration of lorazepam for convulsive seizures lasting less than 5 minutes causes more vital instability than just using supportive measures.  Methods: This is an IRB approved retrospective study. We included non-incarcerated patients who are 18 years or older and who had a witnessed convulsive seizure that lasted < 5 minutes as documented in the medical recordrs. We divided the enrolled subjects into lorazepam receiver and untreated. Subjects who are lorazepam treated are further divided into three groups (<= 2 mg, 2-4 mg, 4-8 mg). We ran a univariate logistic regression model for the outcome of vital instability (respiratory and/or circulatory) after an acute convulsive seizure lasting < 5 minutes. This was followed by a multivariate regression model to identify the remaining significant variables. Results: A total of 171 subjects who had acute convulsive seizure < 5 minutes out of 1052 reviewed medical records were included. Of these, 97 patients (56.7%) received emergent lorazepam treatment. 23 out of the 97 subjects (23.7%) became vitally unstable. One out of the 74 subjects (1.4%) of those who did not receive lorazepam became vitally unstable. Administering lorazepam for controlling < 5 minute-seizure was significantly associated with vital instability (OR=20.84, p=0.003). This was also dose dependent. Lorazepam doses of <= 2mg, 2-4 mg, and 4-8 mg increased the odds of having vital instability by 6.7, 43, and 155 times than when no drug was administered (p= 0.015, 0.0001, 0.001 respectively). In addition, there was increasing odds among women and older population (OR=4.36, 1.03, p=0.012, 0.037 respectively). Conclusions: Lorazepam administration for acute convulsive seizures not meeting the status epilepticus criteria might lead to vital instability which is dose dependent. The increased vital instability among selective groups might be due to hyperactive or more labile autonomic responses among these populations. Acute convulsive seizures (lasting < 5 minutes) are usually self-limiting and require no intervention other than supportive measures. Funding: No funding