[Effects of pneumoperitoneum on renal hemodynamics and function of dogs under volume and pressure-controlled ventilation.].

BACKGROUND AND OBJECTIVES There are no studies associating ventilatory mode effects on renal repercussions during pneumoperitoneum. This study aimed at evaluating pneumoperitoneum-induced renal hemodynamics and function changes in dogs under volume and pressure controlled ventilation. METHODS This study involved 16 dogs anesthetized with sodium thiopental and fentanyl, which were divided in two groups: Group 1: volume controlled; and Group 2: pressure controlled, both submitted to 10 and 15 mmHg pneumoperitoneum. The following parameters were evaluated: renal blood flow, renal vascular resistance, sodium para-aminohippurate clearance, plasma sodium, plasma potassium, plasma osmolality, creatinine clearance, filtration fraction, urinary volume, urinary clearance, osmolar clearance, free water clearance, sodium clearance, sodium urinary excretion, sodium fractional excretion, potassium clearance, potassium urinary excretion and potassium fractional excretion. Data were collected in 4 moments: M1 before pneumoperitoneum, M2, 30 minutes after 10 mmHg pneumoperitoneum, M3, 30 minutes after 15 mmHg pneumoperitoneum, M4, 30 minutes after pneumoperitoneum deflation. RESULTS Sodium para-aminohippurate and creatinine clearance remained constant for both groups throughout the experiment. Plasma sodium and potassium were not changed. There has been potassium clearance and fractional excretion decrease as from M2 in both groups. CONCLUSIONS Ventilatory modes have not promoted renal hemodynamic differences between groups. Pneumoperitoneum, by compressing renal parenchyma, may have determined changes in potassium reabsorption and/or secretion.