Dopamine infusion and fluid administration improve renal function during laparoscopic surgery

Background: Previous studies have documented the negative influence of pneumoperitoneum on cardiac and renal function during laparoscopy. In this respect, regard there is a lack of data regarding the use of an appropriate management of fluid therapy to decrease these side effects. The aim of this study was to investigate the cardiac and renal responses to the administration of different amounts of crystalloid solution, alone or in association with dopamine during laparoscopy. Methods: Sixty ASA I patients undergoing laparoscopic surgery for endometriosis were randomly assigned to three groups. Group A was given saline solution at 5 ml/kg/h; group B received saline solution at 5 ml/kg/h and dopamine 3 mg/kg/min, and group C received saline solution at 10 ml/kg/h. Patients received A, B or C peri-operatively. Renal function was evaluated by assessing total intraoperative diuresis and estimated glomerular filtration rate. Vasopressin plasmatic levels before and after surgery were measured. Trans-thoracic echocardiography was performed to estimate left ventricular filling pressure by using Tissue Doppler Imaging and registering the E/Ea ratio every hour after pneumoperitoneum. Results: Total intraoperative diuresis was impaired in group A and significantly increased in group C (p<0.001). In group A estimated glomerular filtration rate significantly decreased after the end of surgery (p<0.003) and vasopressin significantly increased (p<0.001). The E/Ea ratio was significantly increased in group C (p<0.001). The infusion of saline solutions with the addition of dopamine slightly affected this parameter. Conclusion: A low rate of saline infusion could lead to an impaired renal function during laparoscopic surgery. This could be prevented by increasing the amount of saline solutions infused per hour or by adding a dopamine infusion.