Direct measurement of intra-abdominal pressure in various conditions.

OBJECTIVE

To standardise a direct method for measuring intra-abdominal 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 in 4 groups: control (n = 11), hernia (n = 8; 6 umbilical and 2 incisional), mass (n = 7; 6 enlarged spleen and 1 carcinoma of sigmoid), and obese (n = 8; a mean of 40% above expected weight).

INTERVENTIONS

Measurement of IAP with a Verres needle connected to a pressure transducer with the patient at rest, straining, supine, erect, and before and after anaesthesia. Intrarectal pressure was measured simultaneously.

MAIN OUTCOME MEASURES

Reproducibility and correlation between the two measurements.

RESULTS

The hernia group had significantly lower IAP than controls both at rest and on straining (mean (SD) 2.7 (1.5) cm H2O compared 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 the 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 anaesthesia in all groups, and no significant difference between intrarectal pressure and IAP in any group.

CONCLUSION

The method of measuring IAP is reproducible. Intrarectal pressure is similar to IAP and can therefore be used instead of it.