Accuracy of renal blood flow assessment by transesophageal echocardiography during carbon dioxide pneumoperitoneum / 中华麻醉学杂志

ABSTRACT

Objective To determine the accuracy of renal blood flow assessment by transesophageal echocardiography (TEE) during carbon dioxide (CO2) pneumoperitoneum.Methods The left renal arterial diameter (RAD) and the Doppler velocity time integral (VTI) were measured by TEE before peumoperitoneum (T0, baseline), at 1, 5, 10, 15, 20 and 30 min of pneumoperitoneum and 1 and 5 min after deflation in 35 patients undergoing elective laparoscopic cholecystectomy. The left renal blood flow (LRBF) and the left renal blood perfusion resistance (LRPR) were calculated according to the following formulae LRBF = 1/4π x RAD2 x VTI x HR, LRPR = MAP/LRBF.Three months later, the TEE images of 10 cases were randomly selected and reviewed by the same and another research team member to check the repeatability and consistency of the LRBF determination during operation, respectively. The quality of the TEE images was evaluated by another specialist.Results Before pneumoperitoneum, 94% of the TEE images were rated as satisfactory. There was no significant difference between the qualities of the TEE images obtained before and during pneumoperitoneum. The variabilities between the RADs measured by TEE during and 3 months after operation were 9.28% by the same team member and 8.71% by another team member. The variabilities between the VTIs measured by TEE during and 3 months after operation were 5.61% by the same team member and 6.25% by another team member. The linear regression analysis of the LRBF showed that the slope and the intercept were 1.05 and 31.4 ml/min respectively by the same member and 0.92 and 47.3 ml/min respectively by another member. The LRBF was decreased during pneumoperitoneum and the LRPR was increased.Conclusion TEE can be used to accurately monitor the changes in renal blood flow during CO2 pneumoperitoneum.