A comparison of propofol and remifentanil for sedation and limitation of movement during periretrobulbar block

Abstract

Study Objectives: To compare clinical conditions in patients sedated with propofol or remifentanil during combined peri-bulbar and retrobulbar block (PRBB) for cataract surgery. Design: Prospective, randomized, double-blind study. Setting: Private clinic. Patients: 106 ASA physical status I and II patients scheduled for cataract surgery. Interventions: Patients were randomized to receive either 0.5 mg/kg propofol (Group P) or 0.3 μmg/kg remifentanil (Group R) as an intravenous (IV) bolus 1 minute prior to PRBB. At the same time, patients in both groups also received 0.5 to 1 mg midazolam IV. Movement of the hands, arms, head, and eyes were counted during each stage of the procedure by an observer who was blinded to the sedation used. Heart rate (HR), blood pressure (BP), respiratory rate (RR), expiratory CO 2 (PECO 2), and hemoglobin oxygen saturation (SaO 2) were recorded every minute for 10 minutes after the PRBB. Anesthetic complications, recall, and the pain experienced with the block and surgery were compared between the two groups. Means and variance of the results were compared with one-way analysis of variance and Fisher’s exact test. Measurements and Main Results: Movements of the hands, arms, and head were significantly greater in Group P during all stages of the block. Almost no movements were recorded in the remifentanil group. Immediately after the PRBB (1 to 6 min), HRs were higher in Group P (73 ± 11 bpm vs. 67 ± 10 bpm; p = 0.0075), whereas the RRs were slower in Group R for the period 1 to 5 minutes after the PRBB (16 ± 5 breaths/min vs .14 ± 4 breaths/min; p = 0.0206). At these times, the mean PECO 2 was higher in Group R (36 ± 7 mmHg vs . 32 ± 9 mmHg; p = 0.0125). Nineteen patients in the propofol group sneezed during the medial peribulbar injection compared with none in the remifentanil group. Anesthetic and surgical complications were unremarkable and similar for the two groups. Conclusions: Respiratory depression with remifentanil was mild and not clinically significant. Remifentanil sedation for this application was superior to sedation with propofol.