Patient-controlled sedation using propofol for dressing changes in burn patients: a dose-finding study

The first change of dressings after skin grafting in burn patients is a source of great anxiety because of pain anticipation and the immediate and first confrontation with the result of skin grafting. We designed this dose-finding study to determine the feasibility and safety of patient-controlled sedation (PCS) using propofol during these procedures. Twenty patients were familiarized with the PCS and asked to use PCS whenever they felt uncomfortable or anxious. Analgesia was provided by a single bolus of morphine IV 15 min before the procedure according to their daily intake. The first 10 patients used a fixed bolus of propofol 0.3 mg/kg and a lockout of 5 min. The degree of sedation was measured using bispectral index (BIS) monitoring. Demands versus delivery of propofol boluses were recorded. Within 1 h after the procedure, pain intensity was evaluated and satisfaction scores obtained from patients and nurses performing the dressing changes. In the first 10 patients, there were no respiratory rates <10 breaths/min, systolic and diastolic blood pressure were within 25% of baseline values, and peripheral saturation stayed more than 94% with additional small flow oxygen via nasal insufflation. There were double the demands than actual deliveries of propofol boluses. The BIS did not show significant decreases of <80 in any patient reflecting an insufficient state of sedation. Because the interim analysis of the efficacy of the PCS setup showed an insufficient state of sedation, a different PCS setup was evaluated in a second group of 10 patients (an individualized propofol bolus, titrated to achieve a significant decrease of BIS or a sleepy state, and no lockout period). The second group of patients showed a more effective sedation, with respiratory and hemodynamic variables being not significantly different from the first group of patients. PCS with propofol is feasible in burn patients and can be used safely. To provide an optimal sedation, we suggest to initially titrate the bolus to achieve a significant decrease of BIS or a clinically effective state of sedation and to abolish the lockout interval.