Background: Intraabdominal pressure (IAP) has been considered responsible for adverse effects in trauma and other abdominal catastrophes as well as in formation and recurrence of hernias. To date, little information is available concerning IAP in normal persons. Our purpose in this study was to measure the normal range of IAP in healthy, nonobese adults and correlate these measurements with sex and body mass index (BMI).
Methods: After Institutional Review Board approval, 20 healthy young adults (< or =30 years old) with no prior history of abdominal surgery were enrolled. Pressure readings were obtained through a transurethral bladder (Foley) catheter. Each subject performed 13 different tasks including standing, sitting, bending at the waist, bending at the knees, performing abdominal crunches, jumping, climbing stairs, bench-pressing 25 pounds, arm curling 10 pounds, and performing a Valsalva and coughing while sitting and also while standing. Data were analyzed by Student's t-test and Pearson's correlation coefficients.
Results: Intraabdominal pressure was measured in 10 male and 10 female subjects. The mean age of the study group was 22.7 years (range, 18-30 years), and BMI averaged 24.6 kg/m(2) (range, 18.4-31.9 kg/m(2)). Mean IAP for sitting and standing were 16.7 and 20 mm Hg. Coughing and jumping generated the highest IAP (107.6 and 171 mm Hg, respectively). Lifting 10-pound weights and bending at the knees did not generate excessive levels of pressure with the maximum average of 25.5 mm Hg. The mean pressures were not different when comparing males and females during each maneuver. There was a significant correlation between higher BMI and increased IAP in 5 of 13 exercises.
Conclusion: Normal IAP correlates with BMI but does not vary based on sex. The highest intraabdominal pressures in healthy patients are generated during coughing and jumping. Based on our observations, patients with higher BMI and chronic cough appear to generate significant elevation in IAP. Thus, this group of patients may potentially be at increased risk for abdominal wall hernia formation following surgery.