Liberal Versus Restrictive Fluid Therapy for Morbid Obese Women Undergoing Laparoscopic Bariatric Surgery

Objectives: To evaluate the effect of fluid therapy on pulmonary and kidney functions in morbid obese patients Patients undergoing bariatric Surgery.Patients and Methods: Seventy-four morbidly obese females were randomly divided according to flow rate of Intraoperative (IO) and PO fluid therapy; 5ml/kg/hr in Group R and 7ml/kg/hr in Group L. Evaluated parameters included determination of Body Mass Index (BMI), Pulmonary Function Testing (PFT), arterial blood gases analysis, and calculation of Pa02/Fi02 ratio. Blood samples were obtained for ELISA estimation of Cystatin C (CysC), plasma Neutrophil Gelatinase- associated Lipocalin (pNGAL) and Serum Creatinine (S Cr). All estimated parameters were re-evaluated during immediate PO period and outcomes were defined as the frequency of PO Acute Lung Injury (ALI), Acute Kidney Injury (AKI) and significant changes of estimated parameters.Results: Liberal IO fluid intake allowed significantly better hemodynamic data compared to Group R. At 4-hr PO, mean FVC was significantly decreased in both groups compared to preoperative estimates, but other estimated PFT showed non-significant difference. Mean IO and PO Pa02/Fi02 ratio were significantly lower compared to preoperative ratio in both groups till POD1 without significant difference between both groups. Estimated S Cr at 48-hr PO defined 13 AKI patients in Group R and 5 in Group L with non-significant difference, but mean increase of S Cr was significantly higher in Group R compared to Group L. At 48-hr PO, mean S Cr and CysC and plasma NGAL levels in total and AKI patients of Group R were significantly higher than control and preoperative levels and 48-hr PO levels of Group L.Conclusion: Crystalloid fluid therapy at rate of 7/ml/kg/hr induced non-significant impact of pulmonary functions and tissue oxygenation, but significantly minimized the frequency of AKI as judged by plasma NGAL and serum cystatin C levels estimated 48-hr PO kidney.