Effect of Remifentanil on Intra-Ocular Pressure in Cataract Surgery under General Anesthesia with Isoflurane

One of the important aims in anesthetic management during ocular surgery is to provide adequate control of intraocular pressure (IOP) and increasing of this pressure would cause some dramatic complications even though visual loss. The aim of this research was to evaluate the effects of adding remifentanil to isoflurane anesthesia on intraocular pressure (IOP) and hemodynamic responses after intubation and during cataract surgery. This study was conducted as randomized clinical trial. Forty patients (20 in each group) enrolled and assigned in two group, isoflurane + remifentanil (R), and isoflurane + placebo (P). Anesthesia was induced in both groups with Na-thiopental 5 mg/kg and atracorium 0.5 mg/kg body weight. In group (R), the patients received1 µg/kg as bolus dose of remifentanil and then continuous infusion 0.1 µg/kg/min was started. In placebo group, saline was infused. IOP and mean arterial pressure (MAP) was measured at 8 different times (zero time, after premedication, after induction of anesthesia, immediately 3 and 6 min after intubation, at the end of surgery and 5 min after remifentanil stopping) by a blind surgeon to research. Primary IOP in group R was 12.7±3.1 mmhg, and in group P was 13.7±3.4 mmHg. After injection of premedication and induction drugs IOP was decreased obviously in two groups. In both groups mean IOP increased after intubation significantly and reach to 12.1±2.8 mmhg and 14.2±3.2 respectively in group R and P that this difference was not significant. Comparison of MAP between two groups only in third measure (after induction of anesthesia) was meaningful (74.6±14.9 in group R and 88.2±14.1 mmhg in group P) (p=0.005). This research was shown that adding of remifentanil to isoflurane in cataract anesthesia could prevent from increasing of IOP due to tracheal intubation.