Intra-abdominal hypertension in the critically ill: Interrater reliability of bladder pressure measurement

PurposeIntra-abdominal hypertension is frequently underdiagnosed and defined by intra-abdominal pressure (IAP) 12 mm Hg or higher. Increasing IAP may compromise organ viability and culminate in abdominal compartment syndrome. Bladder pressure measurement is a surrogate for IAP, but measurement properties are unknown in the intensive care unit. Our primary objective was to assess the agreement of bladder pressure measurements in critically ill patients.MethodsWe conducted an observational study examining the correlation of measurement variability of bladder pressure. Four raters (2 nurses and 2 physicians) measured IAP. Patient's age, Acute Physiology and Chronic Health Evaluation II, body mass index, mechanical ventilation parameters, and demographics were collected.ResultsFifty-one patients had bladder pressures measured in quadruplicate, producing 204 measurements. Among 51 patients, the mean age was 61.9 years, Acute Physiology and Chronic Health Evaluation II was 23.8, and body mass index was 27.8 kg/m2. The average bladder pressure was 12.4 (SD, ± 6.2) mm Hg. The interrater agreement by intraclass correlation coefficient was 0.745 (95% confidence interval [CI], 0.637-0.825), 0.804 (95% CI, 0.684-0.882), and 0.626 (95% CI, 0.428-0.767) among all raters, physicians, and nurses, respectively.ConclusionsAgreement on bladder pressure was high among 4 clinicians and were not significantly different between physicians and nurses. Given that medical/surgical treatments are considered on bladder pressure values, understanding their reliability is essential to monitor critically ill patients.