Introduction: Accurate measurement of intra-abdominal pressure (IAP) is vital in critical care, as intra-abdominal hypertension can lead to organ dysfunction and increased mortality. Current guidelines recommend measuring IAP via the bladder in supine, but clinical realities often dictate patient positioning. While body position effects on IAP have been studied, the accuracy of bladder-based IAP measurements across different positions remains unclear. This study aims to quantify IAP variations in multiple body positions and compare the precision of a specialized bladder catheter method with the established gold standard Kron technique.
Methods: A prospective study was conducted on adult ICU patients requiring urinary catheterization. Intra-abdominal pressure was measured using a specialized bladder catheter and the standard Kron technique across seven positions, from supine to 45° inclines. Patient demographics, BMI, and SOFA scores were recorded. An analysis compared measurement techniques and evaluated positional effects on IAP.
Results: Our study of 25 ICU patients revealed position-dependent IAP variations. Mean values increased from 9.77 mmHg (supine) to 10.44 mmHg (reverse Trendelenburg) and 14.90 mmHg (head-elevated). The specialized catheter showed strongest agreement with the Kron technique in reverse Trendelenburg (bias: -0.27 mmHg) and least in head-elevated positions (bias: 1.54 mmHg). Concordance coefficients were highest in supine (92.12%) compared to reverse Trendelenburg (95.34-100.00%). Correlation coefficients were 0.80, 0.91, and 0.93 for supine, reverse Trendelenburg, and head-of-bed positions, respectively. Error-grid analysis revealed no high-risk errors and 2.66% medium-risk errors in head-elevated positions.
Conclusions: This study demonstrates the significant impact of body position on IAP measurements in ICU patients. Our findings reveal high concordance between a specialized bladder catheter and the gold standard Kron technique, particularly in reverse Trendelenburg positions. These results have important implications for IAP monitoring across various clinical situations, potentially enhancing the management and outcomes of intra-abdominal hypertension when patient positioning deviates from current guidelines.
