Arterial to end tidal carbon dioxide pressure gradient during laparoscopic surgery: is it affected by obesity?

ABSTRACT

In this study changes in arterial to end tidal carbon dioxide pressure difference [PaCO[2] P[E] Co[2]] were determined in 40 ASA I and II female patients of different body weights undergoing laparoscopic surgery. They were classified into 4 equal groups, 10 patients each, according to their body weights using Broca index for obesity. Samples for measurement of arterial Co[2] tension were obtained before, during, after insufflation and before extubation. Our results showed a non significant changes in PaCo[2]-P[ET] Co[2] gradient in patients with body weight up to 60% greater than ideal weight during all phases of measurements while a high significant differences were recorded in obese patients of>60% greater than ideal weight during and after insufflation. End tidal Co[2] value have been found to be reliable in obese patients up to 60% greater than ideal weight but unreliable in obese patients of >60% greater than ideal weight. We concluded that arterial CO[2] tension should be considered in those patients to avoid hypercarbia during laparoscopy