Clinical validation of an intra-abdominal pressure monitoring system by comparison with pneumoperitoneum pressure

In critically ill patients, intra-abdominal hypertension (IAH) is associated with organ dysfunction and increased mortality. Acute kidney injury may occur early, since the kidney is particularly vulnerable to elevated intra-abdominal pressure (IAP). Accurate and timely measurement of IAP is essential for early detection of IAH and the initiation of appropriate therapeutic interventions. Therefore, the aim of this study was to assess the accuracy of an IAP monitoring system compared to a reference standard, the CO2 insufflator, during laparoscopy. The second aim was to assess the changes in renal biomarker levels during and after increases in IAP through pneumoperitoneum. A prospective cohort study in patients undergoing laparoscopy at the University Medical Center Groningen. IAP measurements were performed with a urinary catheter using an IAP monitoring system (Accuryn® Monitoring System, Accuryn Medical) and compared to the pressure set at the CO2-insufflator system. Bland-Altman analysis was performed with accounting for repeated measures. Urine samples were collected at several time-points and Kidney Injury Molecule 1 (KIM-1), Tissue Inhibitor of Metalloproteinase 2 (TIMP-2), urinary Neutrophil Gelatinase-Associated Lipocalin (NGAL), Liver-type Fatty Acid-Binding Protein (L-FABP), and albumin-creatinine ratio were measured. Between March 2025 and January 2026, 99 measurements were performed in 29 patients. One patient (3%) underwent hemicolectomy, and 28 patients underwent endometriosis surgery (97%). Analysis showed a bias of -1.4 mmHg (95% CI (-1.96 - (-0.82)) and limits of agreement of - 5.96 mmHg and 3.2 mmHg (95% CI -6.8-3.99) between the IAP monitoring system and the CO2-insufflators. The precision was 2.3 mmHg. The levels of renal biomarkers KIM-1, TIMP-2 and albumin/Cr ratio increased during laparoscopy compared to baseline, suggesting that relatively small IAP increases during laparoscopy have a subclinical effect on the kidney. The IAP monitoring system underestimated the IAP set by the CO2-insufflator by approximately 1 mmHg. The wide limits of agreement warrant cautious interpretation. Overall, the IAP monitoring system showed reasonable accuracy and precision. The increase of several renal biomarkers during laparoscopy compared to baseline may reflect a direct effect of elevated IAP on the kidney.