[Propofol versus diazepam. Sedation in ophthalmologic surgery under local anesthesia]

This prospective study was designed to evaluate the sedative effect of two different anaesthetic drugs in patients undergoing ophthalmic surgery. Propofol is an intravenous hypnotic agent with a short half-life of about 30 min. A constant high oxygen saturation in continuous pulse oximetry was achieved in previous studies using propofol for sedation. Furthermore, an IOP-lowering effect was proved. Propofol was compared to diazepam, a well-established sedative, which has been used for many years for sedation of patients in local anaesthesia. METHOD. One hundred patients of comparable anaesthesiologic risk (ASA classes 2-4) undergoing identical surgical procedures received either propofol (n = 50), or diazepam (n = 50). Propofol was infused at a rate of 0.8-3.0 mg/kg/h, while diazepam was given as a slow intravenous bolus of 5 mg before surgery. All patients were monitored by continuous pulse oximetry. RESULTS. Oxygen saturation of patients receiving propofol was never less than 96%. In contrast, oxygen saturation of patients sedated by diazepam dropped to 85%, especially for the first 5 min following administration, before improving to 95% during the next 10 min. None of the patients who received propofol showed signs of motor unrest, a great handicap in ophthalmic surgery, while four patients who received diazepam were restless enough to hamper the procedure. None of the patients who received propofol developed respiratory depression. In contrast, marked respiratory depression, motor agitation, and postoperative fatigue slowing mobilization were common in patients who received diazepam.