Deferral of the rectal examination in blunt trauma patients: A clinical decision rule

Objectives: To develop a clinical decision rule that would allow for the safe deferral of the digital rectal examination (DRE) in blunt trauma patients. Methods: The authors reviewed the medical records of all adult blunt trauma patients meeting trauma team activation criteria over a 14-month period. The results of the DRE and six predictor variables-abnormal neurologic examination, abdominal tenderness, pelvic stability, blood at the urethral meatus, blood pressure <90 mm Hg, and age over 65 years-were recorded. Patients with abnormal DREs had their discharge summaries reviewed for specific criteria to determine if the abnormal DRE was a true- or false-positive examination. Predictor variables were entered into a classification and regression tree (CART) analysis designed to predict true-positive abnormal DREs. Results: Of the 579 patients, 53 had abnormal DREs, 34 of which were true positives. CART analysis retained three predictors, abnormal neurologic examination, blood at the urethral meatus, and age over 65 years, and accurately classified all patients with a true-positive abnormal DRE. The probability of a true-positive abnormal DRE in a patient with a normal neurologic examination, no blood at the urethral meatus, and age less than 65 years is between 0% and 0.8%. Conclusions: Adult patients with blunt trauma and a normal neurologic examination, with no blood at the urethral meatus, and who are less than 65 years old have an exceedingly low likelihood of a true-positive abnormal DRE. If validated, patients who meet these three criteria may have the DRE safely deferred.