Use of gastric balloon manometry for estimation of intra-abdominal pressure in horses.

REASONS FOR PERFORMING STUDY: Standing laparoscopic procedures, facilitated by abdominal insufflation with carbon dioxide, are being employed to an increasingly greater extent in horses. However, a sustained increase in abdominal pressure may be life-threatening. A practical method for intra-abdominal pressure (IAP) assessment is imperative. Although indirect methods for estimating IAP have been extensively studied in man, little work has been performed in veterinary medicine. OBJECTIVES: To investigate the utility of gastric manometry for purposes of evaluating IAP in horses. METHODS: Gastric pressure (P(ga) ) was estimated by balloon manometry in 8 healthy, mature horses, before and during a 30 min passive pneumoperitoneum induced by right paralumbar puncture. The balloon manometer was positioned within the gastric lumen and inflated using 2 separate volumes of air: 10 and 50 ml. P(ga) Gastric pressure was determined at baseline (0) and 5, 15 and 30 min after induction of passive pneumoperitoneum. Intra-abdominal pressure was measured directly by right paralumbar puncture using an 8 gauge needle at baseline and immediately following establishment of passive pneumoperitoneum. RESULTS: Baseline IAP values were negative and increased (P≤0.05) during development of passive pneumoperitoneum. However, recorded P(ga) measurements for both inflation volumes were positive before (baseline) and during the course of the passive pneumoperitoneum. Measured P(ga) values did not correlate with IAP at any time. CONCLUSIONS AND POTENTIAL RELEVANCE: Our results suggest that the indirect method used in human patients for estimating IAP by P(ga) is not applicable for horses.