Objective: This study aimed to clarify the significance of diagnostic paracentesis (DPC) and ascites analysis in the preoperative diagnosis of strangulated small bowel obstruction (SBO). Methods: Between June 2008 and May 2018, 38 patients underwent DPC and ascites analysis based on a preoperative diagnosis of strangulated SBO. The patients were divided into two groups based on the intraoperative macroscopic bowel condition: the strangulated (26 patients) and simple (12 patients) groups. The following factors were investigated and compared between the two groups: patient characteristics, preoperative vital signs, blood test results, ascites analysis results white blood cell [WBC] and red blood cell [RBC] counts, and lactate dehydrogenase and creatinine phosphokinase levels), and computed tomography (CT) findings. Results: No procedure-related complications were noted. The vital signs did not differ significantly between the two groups. The arterial base excess (BE) level was significantly lower in the strangulated group than in the simple group, and a BE level of ≤ -1.1 mmol/L had a sensitivity of 65%, specificity of 92%, and overall accuracy of 74% for differentiating the two groups. The ascites RBC count was significantly higher in the strangulated group than in the simple group, and an ascites RBC count of ≥ 20,000/mm3 had a sensitivity of 81%, specificity of 83%, and overall accuracy of 82% for differentiating the two groups. Regarding the distribution of the patients, 24 (92%) patients of the strangulated group were present in the area of BE level of ≤ -1.1 mmol/L or ascites RBC count of ≥ 20,000/mm3. Strangulation sign on CT, besides accumulation of ascites, was more frequently and significantly detected in the strangulated group than in the simple group. Conclusion: Our results suggest that DPC and ascites analysis, particularly ascites RBC count, are significant in the preoperative diagnosis of strangulated SBO when combined with CT findings and BE level.
