The accuracy of a new noninvasive approach using physical examination combined with ultrasonography to detect intraabdominal hypertension.

Intra-abdominal hypertension (IAH) is common in critically ill patients and associated with increased morbidity and mortality. While intravesical manometry is the gold standard for measuring intra-abdominal pressure (IAP), its applicability may be limited in some clinical settings. This study evaluated the accuracy of a noninvasive bedside method combining physical examination and ultrasonography to assess the ratio of the maximal anteroposterior to transverse abdominal diameter (AP-T ratio) for detecting IAH. This cross-sectional diagnostic study was conducted in the surgical ICU of a tertiary care hospital. Intravesical pressure was measured as the reference standard. The AP-T ratio was assessed at the L2 level by two blinded investigators. Among 67 patients, 18 were diagnosed with IAH. The AP-T ratio showed a strong correlation with IAP (r = 0.70, P < 0.001). An AP-T ratio ≥ 0.56 demonstrated 83% sensitivity, 84% specificity, and an AUROC of 0.84 for detecting IAH. After adjusting for BMI, the association remained significant. Diagnostic performance was highest in patients with normal BMI. The AP-T ratio was predominantly influenced by the anteroposterior diameter. This simple, noninvasive technique may serve as a practical alternative when standard IAP measurements are not feasible. Further validation in patients with severe IAH or abdominal compartment syndrome is warranted.Thai Clinical Trials Registry reference number TCTR20220831002.