Highlights from #AAST2014 - DPL is still useful for penetrating trauma

Resident Reza Salabat presented our work on DPL for Thoracoabdominal Stab Wounds.

A COMPARISON OF DIAGNOSTIC PERITONEAL LAVAGE TO COMPUTED TOMOGRAPHY IN THE DIAGNOSIS OF THORACO-ABDOMINAL STAB WOUNDS

Reza Salabat MD, Andrew Dennis DO, John Kubasiak MD, Adelaide Kaczynski BS, Samuel Kingsley MD, Elizabeth Gwinn MD, Kimberly Joseph* MD, Frederic Starr MD, Dorion Wiley MD, Faran Bokhari MD, Kimberly Nagy* MD, Cook County Hospital

Invited Discussant: Leonard Weireter, Jr., MD

Introduction: Studies have reported 27% occult diaphragmatic injury due to stab wounds (SW) to the thoraco-abdomen (TA), with nearly 36% mortality if found incarcerated. The computed tomography (CT) is a widely used initial diagnostic tool, but it lacks the sensitivity to detect diaphragm injuries. We assessed the application of diagnostic peritoneal lavage (DPL) in determining missed abdominal and/or diaphragmatic injuries by CT and the ability to predict a therapeutic laparotomy in patients with SW to TA region.

Methods: Data was collected prospectively from 2006 to 2011. Inclusion criteria consisted of hemodynamic stability and patients who underwent both CT and DPL. Patients were excluded if they were hemodynamically unstable, had evisceration or peritonitis, or had only one of the above tests. A positive DPL was defined as RBCs>10,000/mm3. A positive CT was defined as free air, intra-abdominal organ injury/laceration or hematoma adjacent to an organ. Sensitivity (SN), specificity (SP) were calculated independently for DPL and CT. A therapeutic exploratory laparotomy was defined as presence of an injury, which required intervention.

Results: During the study period, there were 192 patients with SW to TA of which 58 met our criteria. DPL resulted in 12 true positive (TP), 0 false positive (FP), 1 false negative (FN) and 45 true negative (TN) results for detection of injury, whereas CT scan was shown to have 7 TP, 0 FP, 6 FN, and 45 TN tests. Sensitivity (SN) was demonstrated to be 92% vs. 53% for DPL vs. CT, respectively. Specificity was 100% for both groups. When only therapeutic lapatotomy was considered, we found 12 TP, 0 FP, 0 FN, and 45 TN DPL results, compared to CT scan which had 6 TP, 0 FP, 6 FN, and 45 TN tests. Sensitivity was demonstrated to be 100 vs. 50% for DPL vs. CT, respectively. Specificity was 100% for both groups. Notably, CT missed 1 colon, 2 splenic, 3 hepatic, and 7 diaphragmatic injuries. Four of the diaphragmatic injuries were found on the left anterior and lateral aspects

Conclusion: DPL was found to be superior to CT both for detection of intra-abdominal organ injury and for prediction of therapeutic exploratory laparotomy. CT missed all diaphragmatic injuries as well as 6 other intra-abdominal injuries. We conclude that CT, despite improvements in technology, remains a poor test for evaluating the diaphragm after penetrating TA trauma. When attempting to rule out potentially operative injuries to the diaphragm, DPL continues to be a useful test that should remain in the arsenal of every trauma surgeon.