DIRECT MEASUREMENT OF INTRAABDOMINAL PRESSURE IN VARIOUS CONDITIONS

Objective. To standardise a direct method for measuring intra-abdomina l pressure (IAP), to correlate the results with intrarectal pressure, and to compare the results in various conditions. Design: Prospective open study. Setting: Teaching hospital, Egypt. Subjects: 34 Subjects i n 4 groups: control (n = 11), hernia (n = 8; 6 umbilical and 2 incisio nal), mass (n = 7; 6 enlarged spleen and 1 carcinoma of sigmoid), and obese (n = 8; a mean of 40% above expected weight). Interventions: Mea surement of IAP with a Verres needle connected to a pressure transduce r with the patient at rest, straining, supine, erect, and before and a fter anaesthesia. Intrarectal pressure was measured simultaneously. Ma in outcome measures: Reproducibility and correlation between the two m easurements. Results: The hernia group had significantly lower IAP tha n controls both at rest and on straining (mean (SD) 2.7 (1.5) cm H2O c ompared with 7.0 (5.09) and 6.1 (2.7) compared with 20.5 (7.9), p < 0. 01 in each case). Neither the mass nor the obese group differed from t he controls at rest, but the pressure was higher on straining (31.2 (1 .4) and 33.5 (2.07) cm H2O, respectively, compared with 21.9 (7.3), p < 0.05 in each case). There was a significant drop in IAP after anaest hesia in all groups, and no significant difference between intrarectal pressure and IAP in any group. Conclusion: The method of measuring IA P is reproducible. Intrarectal pressure is similar to IAP and can ther efore be used instead of it.