A pulseless limb poorly predicts an arterial injury in combat trauma

A pulseless limb is considered a hard sign of an arterial injury after penetrating trauma in the civilian population. However, the reliability of this finding has never been examined in combat trauma. The purpose of this study was to examine the reliability of the pulseless limb in the combat trauma population. Reasons for false positive physical examination findings were also identified.

The Joint Theater Trauma Registry identified all patients who presented to a military treatment facility (MTF) in Kandahar, Afghanistan, with a penetrating extremity injury over a 2-year period. Patients found to have a pulse deficit on initial physical examination were followed, and the results of the subsequent computed tomographic angiogram or arteriogram recorded. Patient demographics, injury patterns, and physiological data were examined. Standard statistical analysis was performed.

From 2011 to 2012, 644 patients were treated at a single MTF for lower extremity penetrating injuries. The most common mechanisms of injury were explosions (62%) and gunshot wounds (20%). Of the 577 patients with complete medical records, 448 patients (78%) presented with palpable pulses, 115 patients (20%) presented with a pulseless limb, and 14 (2%) presented with hard signs of vascular injury. Of those with a pulseless limb and abnormal ankle-brachial index (ABI) or no ABI obtained who underwent further radiologic imaging, 38 patients (77%) had no arterial injury identified. Compared with those with a palpable pulse, patients with a pulseless limb without an arterial injury were more likely to have a higher Injury Severity Score (ISS), lower hematocrit, lower pH, greater base deficit, higher heart rate, more frequent use of tranexamic acid, and received greater volumes of packed red blood cells, plasma, and crystalloids.

Our results demonstrate that a pulseless limb is a poor predictor of arterial injury and should not be considered a hard sign of vascular injury in the combat population. Variables including a high ISS, anemia, acidosis, and need for resuscitation products, each a surrogate for injury severity, may contribute to the decreased accuracy of the physical examination in our troops. This may translate into unnecessary immediate exploration or other interventions in patients who present with more significant injuries from the battlefield. Future studies must continue to focus on improved algorithms for diagnostic accuracy of extremity vascular injuries in this population.