When persistent or severe, intra-abdominal hypertension can evolve into abdominal compartment syndrome if timely therapeutic intervention is not rendered. Such interventions rely heavily on dependable, accurate monitoring of intra-abdominal pressure. The most reliable way to monitor intra-abdominal pressure in small animals is by indirectly measuring intravesicular pressure. The objective of this study was to compare the water manometry, external pressure transducer (ExtT), and pressure tip catheter techniques for their accuracy in measuring intravesicular pressure against a known intra-abdominal pressure. We hypothesized that the water manometry technique would be more accurate than the external pressure transducer (ExtT) technique in a canine cadaveric model and that pressure tip catheter would be the most accurate of the 3. Each technique was carried out on 22 small-breed canine cadavers in a randomized order, with incremental increases in insufflation pressure via a supraumbilical Veress needle. Induced abdominal pressure ranged from normal (4 mmHg) up to levels consistent with severe intra-abdominal hypertension (30 mmHg). Tukey's multiple comparison test was used to assess and isolate differences, after the fixed-effects test was applied. There was a statistically significant difference in accuracy with the ExtT technique when compared to insufflation pressure, with a ± 2.63 mmHg overestimation observed (P-value = 0.0041). No statistical difference in accuracy was noted between the water manometry and pressure tip catheter techniques. Study limitations included the cadaveric nature that does not account for direct clinical translation of these findings. In conclusion, of the 2 commonly used techniques, water manometry appears to be more accurate than ExtT. The pressure tip catheter technique appears to be just as accurate as water manometry in this cadaveric model.
Williams et al. (Thu,) studied this question.