Changes in renal blood flow during laparoscopic cholecystectomy

Abstract

Objective To investigate the changes in renal blood flow during laparoscopic cholecystectomy.Methods Thirty-two ASA Ⅰ patients (10 male, 22 female) aged 18-64 yr, weighing 45-81 kg undergoing laparoscopic cholecystectomy were included in this study. Anesthesia was induced with midazolam, fentanyl,propofol and vecuronium and maintained with isoflurane inhalation, continuous infusion of propofol and remifentanil and intermittent iv boluses of vecuronium. The patients were intubated and mechanically ventilated. PET CO2 was maintained at 30-40 mm Hg. The probe of transesophageal echocardiography (TEE) was inserted into esophagus after tracheal intubation. The internal diameter and blood flow velocity and time integral of left renal artery and descending aorta were measured by TEE before (baseline) and at 1, 5, 10, 15, 20 and 30 min of pneumoperitoneum and 1 and 5 min after deflation. The blood flow of left renal artery (LRAF) and decending aorta (DAF) were calculated. The maximal decrease in LRAF and DAF and LRAF/DAF were analyzed. Results LRAF and DAF decreased significantly during pneumoperitoneum compared to the baseline and recovered after deflation. LRAF and DAF decreased maximally by 40% (95% confidence interval (95% CI) 31%-49% ) and 38% (95% CI 31%-44% ) at 8.9 min (95% CI 5.5-12.4 min) and 6.7 min (95% CI 4.0-9.5 min) of pneumoperitoneum respectively. There was no significant change in LRAF/DAF ratio during pneumoperitoneum. Conclusion The renal blood flow decreases at 1-30 min of pneumoperitoneum with the maximum degree of decrease about 40% at about 9 min of pneumoperitoneum and the reason is related to the decrease in the cardiac output. Key words: Cholecystectomy,laparoscopic; Renal blood flow