A comparative study of four combinations of anesthetic drugs for assessing the intraocular pressure changes during gynaecological laparoscopic procedures

AIMS AND OBJECTIVES: Laparoscopic surgery is the choice for gynaecological surgery these days, but pneumoperitoneum (PNO) and trendelenburg position increase the intraocular pressure (IOP) leading to decrease in perfusion of retina and at times the significant risk of ischemic retinopathy. Our present aim is to find out the suitable combination of induction and maintenance agent for combating the increase in IOP by PNO, lithotomy and trendelenburg position, and to study the changes in IOP at different time points and positions in gynaecological laparoscopic procedures. PATIENTS AND METHODS: After taking permission from the Ethical Committee 120 female patients of ASA grade 1 and II were divided arbitrarily in four groups each comprising 30 patients. In group A and B induction was done with propofol 2.5 mg/kg given IV and in group C and D induction was done with thiopentone 5 mg/kg given IV. Atracurium 0.5 mg/kg IV was used as neuromuscular blocking agent (NMBA).Laryngeal mask airway (LMA) was inserted in all the cases and patients were ventilated with Bain's circuit. Maintenance of anesthesia was done with total intra venous anesthesia (TIVA) with propofol and100% oxygen in group A and C. In group B and D maintenance was done with 1% isoflurane with oxygen (O(2)) and nitrous oxide (N(2)O) in the ratio of 40:60. Changes in IOP, heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean blood pressure (MBP) were measured. Baseline readings were taken initially and then 2 min after premedication, 1 min after LMA insertion, 1 min after PNO with lithotomy position, 5 min after 20° head down tilt and PNO in situ and 2 min after exsufflation of PNO with supine horizontal position. RESULTS AND CONCLUSION: To mitigate increase in IOP during gynaecological laparoscopic surgeries, propofol, and propofol TIVA (Group A) proved to be the best option. Propofol and isoflurane (Group B) thiopentone and propofol TIVA (Group C) were not as effective as group A. However, induction with thiopentone and maintenance with isoflurane (Group D) were not effective at all.