A Clinical Comparative Study to Ascertain Efficacy of Circle Absorption System and Bain Breathing System in Maintaining Effective Hypocapnia During Intracranial Surgery

Abstract

AIM OF THE STUDY:To ascertain efficacy of the Circle absorption system and the Bain breathing system in maintaining effective hypocapnia to create a favorable environment for smooth conduct of intracranial surgery, with the help of Capnographic monitoring. MATERIALS AND METHODS: In the study fifty adult patients of ASA-I or II physical status requiring intracranial surgeries under General Anesthesia were selected irrespective of sex and randomly allocated in two groups. In one Group the Circle absorption system and in another Group the Bain breathing system was used for delivery of the anesthetics and performance of IPPV. To avoid variation in observations same premedications, anaesthetic drugs and anaesthetic technique excepting the breathing system varying as per group were used in all the patients of both the groups. Circle absorption system was used with a fresh gas flow of 4.5 Liters and Bain breathing system was used with a fresh gas flow of 6 Liters for maintenance of anaesthesia and performance of IPPV. Pulse rate, SpO2, SBP, DBP and MAP were recorded before induction of Anaesthesia, during induction, after intubation, at the time of incision and every 10mins thereafter till the time of reversal. EtCO2 and FiCO2 were recorded immediately after intubation, at the time of incision and every 10mins thereafter till the time of reversal. Desired level of EtCO2 was maintained by moderate hyperventilation as and when required. Brain relaxation was graded in consultation with the surgeon and by simple visual assessment. RESULTS AND OBSERVATIONS:The study involved analysis of capnometric information acquired following use of both the breathing systems. The ability of both the breathing systems to effectively eliminate Carbon dioxide and their rebreathing characteristics were analyzed from the data obtained. CONCLUSION: It can be concluded that apart from the variation of fresh gas flow required in each system and the rebreathing characteristics of the Bain breathing system both Circle absorption system and the Bain breathing system are equally effective in terms of Carbon dioxide elimination and both can effectively provide a conducive environment for intracranial procedures.