Cardiovascular and Respiratory Effects of Increased Intra-abdominal Pressure with and without Dexmedetomidine in Anesthetized Dogs

Abstract

Intra-abdominal pressure (IAP) elevation during capnoperitoneum can cause adverse cardiovascular and respiratory effects. This study aimed to determine if a sequentially increased IAP affects cardiovascular and respiratory variables in anesthetized dogs and evaluate the effects of constant rate infusion of dexmedetomidine (Dex) on cardiovascular and respiratory variables with increased IAP. Five dogs were anesthetized, instrumented, and the Veress needle was equipped to adjust the IAP using a carbonic anhydrase insufflator. Stabilization was conducted for 1 h, and physiological variables were measured in IAPs of 0, 5, 10, 15, and 20 mmHg and after desufflation. After the washout period, the dogs underwent similar procedures along with constant rate infusion of dexmedetomidine. Cardiovascular effects of increased IAP up to 20 mmHg were not significant in healthy beagle dogs and those administered with dexmedetomidine. In the control group, the arterial pressure slightly increased, but not statistically significant, at an IAP of 20 mmHg compared with that at baseline (mean arterial blood pressure, p = 0.399; systolic arterial blood pressure, p = 0.293; diastolic arterial blood pressure, p = 0.141). When comparing the control and dexmedetomidine groups, overall significant effects of dexmedetomidine were noted on heart rate, cardiac output, and systemic vascular resistance during the experiment. Respiratory effects were not affected by abdominal insufflation when compared between different IAPs and between the two groups. Overall, an increased IAP of until 20 mmHg did not significantly affect cardiovascular and respiratory variables in both control and dexmedetomidine groups. This study suggests that dexmedetomidine infusion administration is applicable in laparoscopic procedures in healthy dogs.