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

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 microg/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 mmHgvs. 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.

Evaluation of anxiolysis and pain associated with combined peri- and retrobulbar eye block for cataract surgery.

STUDY OBJECTIVES: To evaluate five different preoperative anxiolytic regimens in cataract surgery performed under regional anesthesia; to quantify the pain associated with combined peri- and retrobulbar injection (PRBI) of local anesthetic drugs; and to describe a technique of painless eye block. DESIGN: Randomized, double blind, placebo-controlled study. SETTING: Private clinic. PATIENTS: 376 ASA I and II patients presenting for cataract surgery. INTERVENTIONS: Patients were extensively briefed by the nursing staff on the various procedures. Of the 376 study patients, 136 preferred to have no anxiolytic drug. The remaining 240 patients were randomly allocated to one of six groups to receive either 3 mg of bromazepam, 6 mg of bromazepam, 0.5 mg of alprazolam, 1 mg of alprazolam, 5 mg of diazepam, or a placebo on a double-blind protocol. All patients received a standard combined peri- and retrobulbar eye block (PRBB) before surgery. MEASUREMENTS AND MAIN RESULTS: Anxiety at various stages of the procedure and PRBB were measured on visual analog scale (0-10). PRBB pain was compared with pain of intravenous (i.v.) cannula placement. On admission, anxiety of the 136 patients who preferred no anxiolytic premedication was significantly less than that of the 240 patients assigned to one of the six treatment groups (p < 0.05). There was no difference between the six treatment groups in reported anxiety before surgery (p > 0.05) except for Group 1 (3 mg bromazepam), where anxiety increased before and during PRBB administration (p < 0.05). In all six treatment groups, anxiety decreased significantly 30 minutes after medication was administered (p < 0.05). For the total group, 61.18% of patients reported more or equal pain associated with the placement of the 20-gauge i.v. cannula than by the PRBB. Of the patients who received medication, 94% stated that, should they require another eye operation, they would like the same anxiolytic treatment. No patient requested general anesthesia for their next operation or to be rendered unconscious for PRBB. CONCLUSIONS: 1. There was interpersonal variation in the level of preoperative anxiety. 2. In patients who were anxious, the anxiolytic drugs and placebo decreasedanxiety although the level of anxiety did not differ between the anxiolytic drugs or between placebo and the anxiolytic drugs. The only difference was in Group 1 patients (3 mg promazepam), who reported slightly increased anxiety before and during PRBB administration (p < 0.05). 3. Placement of the PRBB is less painful than the insertion of a 20 g i.v. cannula.