A prospective, observational, longitudinal cohort study of sedation practices in SGH intensive care units

Abstract

Background: Critically ill patients require sedation for patient comfort and ventilator synchrony. Despite the extensive use of sedation, to date there is no consensus on the best sedation practices. We attempt to investigate our local sedation practices. Method: This was a single-centre prospective, observation cohort study in medical and surgical intensive care unit (ICU) patients who were ventilated and sedated for more than 24 hours. Baseline demographics were obtained and patients followed-up for 28 days or to ICU discharge. Details on sedatives, ventilation duration, vasopressors and renal replacement therapy use, hospital/ICU length of stay, mortality, delirium, and sedation depth were collected and analysed. Results: From March to July 2012, 58 patients were recruited with a mean Acute Physiology and Chronic Health Evaluation II (APACHE II) score of 20.2 ±8.5. Hospital mortality rates were 32.8%. Patients were followed-up for 387 ICU patient-days. In the early period (first 48 h), the most popular sedative used was propofol (74.1%), followed by morphine (29.3%). In the subsequent period (>48 h), most patients were not sedated (47.6%); morphine became the most popular sedation drug (32.5%) followed by propofol (31%). Ketamine, haloperidol and diazepam were not given. In total, 1994 Richmond Agitation and Sedation Score (RASS) assessments were performed over 387 ICU patient-days; 11.1% of RASS assessments were prescribed a sedation target, and 86% of them met the prescribed targets. Delirium was observed in 22.4% of patients. Compared with medical patients, surgical patients were more likely to be prescribed a sedation target (14.2% vs. 7.4%, p <0.01), require lower doses of sedation, have a RASS score of between −2 to 1 (84.8% vs. 72.3%, p <0.01) and have fewer incidences of delirium (4.1% vs. 12.1%, p =0.01). Conclusion: Propofol and morphine were the most commonly prescribed sedatives. Different sedation practices between units may contribute to a reduction in delirium incidence.