Variation and Accuracy of Intra-Abdominal Pressure Measurement in Different Body Positions: A Prospective Study

Reviewed by Dr Reza Lankarani, General SurgeonFounder | Surgical Pioneering Newsletter and Podcast Series Editorial Board Member | Genesis Journal of Surgery and MedicineWorld Journal of Emergency SurgeryDate of Online Publication: 26 August 2025DOI: https://doi.org/10.1186/s13017-025-00644-01. Concise Overview:This prospective study serves as the first-in-human validation of the TraumaGuard catheter, a novel continuous intra-abdominal pressure (IAP) monitoring device. The primary objective was to validate the TraumaGuard against the intermittent FoleyManometer technique (the gold standard) in a cohort of 25 adult ICU patients. A key secondary objective was to investigate the impact of body position (supine, reverse Trendelenburg, and head-of-bed (HOB) elevation) on both IAP values and measurement accuracy.Key Methods:· Paired IAP measurements were taken using both the TraumaGuard (IAPTG) and FoleyManometer (IAPFM) devices across seven different body positions.· Statistical analysis included Pearson’s correlation, Bland-Altman analysis for agreement (bias and precision), concordance analysis for tracking IAP changes, error-grid analysis for clinical risk, and ROC analysis for diagnosing intra-abdominal hypertension (IAH).Key Findings:· The TraumaGuard catheter demonstrated excellent agreement with the gold standard, particularly in the supine and reverse Trendelenburg positions, with low bias (-0.3 to 0.8 mmHg) and good precision (1.5-1.7 mmHg).· Body position significantly affects IAP. Changing from supine to HOB elevation caused a substantial increase in IAP (from 9.8 to 14.9 mmHg), a change more pronounced in patients with pre-existing IAH.· The device showed excellent diagnostic performance for IAH, with an Area Under the Curve (AUC) of 0.97, sensitivity of 96%, and specificity of 86%.Conclusion: The TraumaGuard catheter is a valid and accurate tool for continuous IAP monitoring. The study confirms that body position is a major determinant of IAP, a critical consideration for managing critically ill patients, especially those mechanically ventilated in semi-recumbent positions.2. Detailed Assessment of Strengths· Innovative Focus: This is the first study to validate a novel "balloon-in-balloon" catheter design in humans, addressing a known limitation of previous continuous IAP devices regarding bladder volume dependency.· Clinically Relevant Protocol: The evaluation across multiple body positions (supine, HOB 15°/30°/45°, reverse Trendelenburg 15°/30°/45°) greatly enhances the clinical applicability of the findings, as ICU and surgical patients are rarely maintained strictly supine.· Rigorous Statistical Analysis: The use of a comprehensive statistical suite (Bland-Altman, concordance, error-grid, ROC analysis) goes beyond simple correlation and provides a robust, multi-faceted assessment of the device's performance and clinical utility.· Adherence to Guidelines: The study design and interpretation of results are explicitly framed within the recommendations of the Abdominal Compartment Society (WSACS), lending credibility and aligning with current expert consensus.· Transparency: The declaration of conflicts of interest is detailed and upfront, which is essential for interpreting industry-associated research.3. Comparison with Latest Related StudiesThe study's findings on the effect of body position on IAP align well with the existing literature, while its core validation work is novel. The table below summarizes the comparison, partially adapted from the article's own comprehensive review.Graphical Comparison: IAP in Supine vs. HOB 30° PositionThis bar chart visually compares the findings of the current study with the pooled average from previous literature,highlighting that while the absolute IAP values in the current study are lower, the relative increase with HOB elevation is consistent.Key Comparisons and Contributions:· Consistent Trend, Different Baseline: The current study reports a lower baseline supine IAP (9.8 mmHg) compared to the pooled average (11.8 mmHg). This could be due to differences in patient populations. However, the direction and magnitude of change with HOB elevation are consistent, reinforcing that HOB elevation significantly increases IAP.· Novel Data on Reverse Trendelenburg: This study provides valuable, less-common data on reverse Trendelenburg positions, showing a more modest increase in IAP compared to HOB elevation.· Validation Focus vs. Phenomenon Observation: Unlike most previous studies that primarily documented the phenomenon of IAP variation with position, this article's primary contribution is the validation of a new continuous monitoring device within that context. 4. Significance and Impact:This study is a significant and welcome contribution to the field of