To compare the effect of positive end expiratory pressure on dynamic pressure volume loop in laparoscopic and non laparoscopic surgeries

It is an comparitive study to find out the optimal Positive end expiratory pressure (PEEP) during laparoscopic surgery using the change in maximum curvature and compliance of the pressure volume loop. After selecting the patients by the inclusion and exclusion criteria, they undergo standard anesthetic technique. Standard monitoring including the spirometry which is routinely performed is attached. After application of various PEEP ( 0, 4, 7 and 10 cmH2O) the spirometry loop is photographed and saved. The study is stopped if there is any hemodynamic disturbances. The study hypothesis is that optimum PEEP can be found by change in maximum curvature.