Factors associated with adverse events during sedation of highly agitated patients in the emergency department

Abstract

BACKGROUND: Patients requiring sedation for acute agitation are a highly vulnerable population. The need for rapid sedation using benzodiazepines or neuroleptics may result in significant adverse events with a rate reported between 13% and 31%. AIM: To identify factors associated with adverse events (AE) during sedation for acute agitation. METHODS: This study reviewed 336 patients sedated with midazolam alone or in combination with either droperidol or olanzapine for AE occurences. AEs were identified prospectively during management of acute agitation. All case histories were also reviewed and data extracted for any unreported pre-defined events. Variables including patient demographics, clinical urgency, sedation, co-morbidities and past history were tested for significant association. Factors significant to a p-value of 0.1 were entered into a regression model to isolate those with independent prediction of adverse events. RESULTS: There were 39 (11.6%) patients who had 50 AEs. The factors increasing risk were: being male (Odds Ratio 1.88, P value 0.08), history of alcohol abuse (1.97, 0.06), or alcohol intoxication on arrival (3.45, 0.002). The protective factors were: regular anti-psychotic use (0.31, 0.007), history of drug abuse (0.49, 0.03), drug intoxication on arrival (0.54, 0.08) and self-presentation (0.6, 0.06). Following logistic regression only regular anti-psychotic use remained independently significant (0.37, 0.03). CONCLUSION: Whilst AEs during acute sedation remain highly problematic for ED staff and patients, there are no factors likely to be readily available to help predict high risk populations. All patients with acute agitation requiring chemical restraint should be monitored closely until the risk of serious AEs has dissipated.