Alfentanil and patient-controlled propofol sedation - facilitate gynaecological outpatient surgery with increased risk of respiratory events.

BACKGROUND Widespread use of patient-controlled sedation (PCS) demands simplicity and a predictable outcome. We evaluated patients' safety and ease of use of PCS for gynaecological outpatient procedures. METHODS In a prospective double-blind study, 165 patients were randomized to use propofol or propofol with alfentanil as PCS combined with local anaesthetic for pain control. Data on cardiopulmonary function, consciousness, and need for interventions were collected at baseline and every fifth minute. The surgeons' evaluation of the ease and the duration of the procedure were recorded. RESULTS One hundred and fifty-five patients used PCS for the entire procedure, 76 patients propofol, and 79 patients propofol/alfentanil. Fifteen procedures in the propofol group were limited or could not be done, compared with four in the propofol/alfentanil group (P = 0.02). The duration of surgery was not affected. The addition of alfentanil affected respiratory function compared with the propofol group: five patients compared with none were manually ventilated (P = 0.03), and two thirds, compared with a quarter, were given supplementary oxygen as their saturation decreased below 90% (P < 0.001). Overall cardiovascular stability was maintained. The propofol group had deeper conscious sedation as measured by the bispectral index (P = 0.03), but all patients could be roused. In the propofol/alfentanil group, five patients became apnoeic and could not be roused. CONCLUSIONS PCS using propofol alone supports patients' safety, as the addition of alfentanil increased the need for specific interventions to maintain respiratory stability. However, alfentanil increases the feasibility of the procedure, as complementary doses of propofol were not required.