Effects of desflurane on systemic, preportal and renal circulatory responses to infra‐renal aortic cross‐clamping in the pig

Background : Different pharmacological approaches have been used in the control of cardiovascular responses to surgical infra-renal aortic occlusion (AXC). The aim of the present study was to explore the modulatory effects of desflurane (DES) on these responses. Methods : The study was performed in normoventilated chloralose-anesthetized pigs (n=14). Measurements included cardiac output (CO), pulmonary vascular pressures, heart rate (HR) and mean arterial pressure proximal to the AXC site (MAP PROX ). Renal arterial (Q REN ) and portal venous (Q PORT ) blood flows were measured ultrasonically. Systemic (SVR), preportal (R PORT ) and renal (R REN ) vascular resistances were derived. Sets of measurements were done a) prior to, b) during and c) 5 min after AXC. This was repeated, in a randomized fashion, at control (no DES) and with 4.9% and 9.8% DES, respectively. Results : DES decreased MAP PROX , CO, HR, SVR, R REN and R PORT . At control, AXC increased MAP PROX (+27%), SVR (+27%), Q PORT (+14%), R PORT (+12%) and R REN (+43%). DES 4.9% did not change this response pattern. With 9.8% DES, the AXC-induced increases in MAP PROX (+17%) and SVR (+21%) were attenuated. At this stage, AXC caused no demonstrable changes in R REN or R PORT , while both Q REN (+16%) and Q PORT increased (+9%). Conclusions : DES effectively controlled increases in proximal blood pressure during AXC. The increases in R REN and R PORT that were seen during AXC at control were inhibited by 9.8% DES. Consequently, at this DES dose, both Q REN and Q PORT increased during AXC.