Propofol and alfentanil infusions for sedation in intensive therapy

Forty-four patients, with admission APACHE II scores between 5 and 24, undergoing mechanical ventilation in the intensive therapy unit, received a sedative regimen consisting of continuous infusions of propofol and alfentanil. Patients were randomly allocated to one of three groups to receive either alfentanil 0.25 microgram kg-1 min-1 (10 patients), 0.50 microgram kg-1 min-1 (15 patients) or 0.75 microgram kg-1 min-1 (18 patients) for analgesia. An infusion of propofol 20-200 mg h-1 ran concurrently to maintain a satisfactory level of sedation. Patients received the infusions for between 4 and 260 h and 38 patients spent more than 90% of this time at satisfactory sedation levels. After stopping the infusions all patients had short times to wakening (mean 3-18 min) and to establish spontaneous respiration (mean 8-28 min), suggesting no significant cumulation. Some depression of blood pressure was seen on starting the infusions, which was in general easily treated with fluids or small increases in inotropic agents. One patient, however, was withdrawn from the trial because of haemodynamic instability. This combination of drugs can be recommended for sedation of general intensive-therapy patients, provided the cost is not felt to be prohibitive.