Measurement of intra-abdominal pressure in term pregnancy: a pilot study

Background: This study was conducted to assess the feasibility of measuring intra-abdominal pressure in term parturients under spinal anesthesia. Methods: Intra-abdominal pressure was measured in 20 term parturients after spinal anesthesia for elective caesarean section. Pressure was measured in the supine and 100 left lateral tilt positions with a constant reference point throughout. Results: Intra-abdominal pressure measurement was feasible and safe to perform. Pressure was significantly lower in the left lateral tilt position than supine (10.9 mmHg +/- 4.67 vs. 8.9 mmHg +/- 4.87, P = 0.0004). The range of intra-abdominal pressure in pregnancy was wide, from 2 to 20 mmHg, with >25% of patients resting with pressures above 12 mmHg in both positions. Conclusions: Under spinal anesthesia, intra-abdominal pressure in >25% of healthy term parturients was > 12 mmHg, which has conventionally been defined as intra-abdominal hypertension. The intra-abdominal pressure in term pregnancy should be performed in the left lateral tilt position to avoid falsely elevated pressure measurements. (C) 2011 Elsevier Ltd. All rights reserved.