Asymptomatic stab wounds of the chest.

In a prospective study of 4,106 consecutive cases of initially asymptomatic stab wounds of the chest, 88% were successfully treated as outpatients after negative findings on a repeat chest x-ray film 6 hours after presentation, 12% of patients required tube thoracostomy for delayed pneumothoraces of hemothoraces, 0.2% required thoracotomy for delayed and continued bleeding or cardiac injuries, 1% of patients with small pneumothoraces (subjectively less than 20%) were observed, and 68% patients remained asymptomatic. The accuracy of the initial chest x-ray film was 95% overall, with a specificity of 99.9%. The negative predictive value of only 87.4% precludes the immediate outpatient management of these asymptomatic patients. The overall mortality was 0.1%, mortality during or following surgery was 50%. Of the four patients with initially unsuspected cardiac injuries, two patients died in the operating room. Asymptomatic patients (with normal findings on chest x-ray films) may be discharged after 8 hours of observation. Asymptomatic patients with nonprogressive small pneumothoraces (less than 20%) not requiring a chest tube may be discharged after 48 hours of observation. Thirty-two percent of those observed for initially small pneumothoraces on chest x-ray films, had progression of their injuries and required tube thoracostomy. All patients should have close outpatient follow-up.