Influence of time on risk of bowel resection in complete small bowel obstruction

BACKGROUND: Little is known about the effect of passing time on risk of resection among patients with complete small bowel obstruction. We sought to provide a benchmark of the relationship of time from symptom onset to surgical treatment on the need for resection in patients with complete small bowel obstruction. STUDY DESIGN: We performed an observational study of patients with surgically treated complete small bowel obstruction at an inner-city urban tertiary referral center and a municipal hospital. Patients were sampled randomly retrospectively (n=60), and prospectively (n=81), for a final sample of 141. Detailed clinical and time data were abstracted from medical records including out-of-hospital examinations. Risk of resection was calculated using actuarial life table methods. Linear regression was used to determine factors affecting time to treatment. RESULTS: All patients were treated surgically for obstruction; 45% underwent resection. Resected patients had longer (11 days versus 8 days; p=0.01) and more complicated (31% versus 14% in ICU; p=0.01) hospital stays. The risk of resection was 4% among patients with 24 hours of unresponsive symptoms; it increased to 10% to 14% through 96 hours, then dropped slightly but did not disappear. Patients treated first with a tube had longer times between first examination and operation, system-time (40.6 hours versus 10.2 hours; p=0.0007), but this was not associated with an increased resection risk. System-times were shorter among patients seen first in the emergency department (median: 25.7 hours versus 59.7 hours; p=0.0001). CONCLUSIONS: Physicians should be cautious in postponing surgery beyond 24 hours in patients with unresponsive symptoms from complete obstruction. The risk of resection rises dramatically, remains elevated through 96 hours of unresolved symptoms, then declines but does not disappear.