Evaluating for Acute Mesenteric Ischemia in Critically Ill Patients: Diagnostic Peritoneal Lavage is Associated With Reduced Operative Intervention and Mortality

The Journal of Emergency Medicine to establish a clinically relevant platelet target to assist with prognostication in patients on antiplatelet therapy with traumatic ICH. Future studies are indicated to further evaluate the platelet thresholds identified in a multicenter fashion with a heterogenous trauma population and to determine whether platelet transfusion can improve outcomes in patients on antiplatelet therapy with ICH. , EVALUATING FOR ACUTE MESENTERIC ISCHEMIA IN CRITICALLY ILL PATIENTS: DIAGNOSTIC PERITONEAL LAVAGE IS ASSOCIATED WITH REDUCED OPERATIVE INTERVENTION AND MORTALITY. Lee MJ, Sperry JL, Rosengart MR. J Trauma Acute Care Surg 2014;77:441 7. The diagnosis of intra-abdominal pathology in the intensive care unit (ICU) patient, specifically acute mesenteric ischemia, necessitating operative intervention is considerably challenging. The mortality of acute mesenteric ischemia remains high, up to 90%. For this reason, rapid diagnosis and intervention are necessary. Computed tomography (CT) is the most commonly used modality to evaluate for acute mesenteric ischemia. This study hypothesizes that diagnostic peritoneal lavage (DPL), compared with CT, reduces the rates of laparotomy, decreases the time to operative intervention, and reduces mortality for critically ill ICU patients with acute mesenteric ischemia. In this retrospective cohort study of all patients admitted to a single-center ICU during a 9-year period, 120 ICU patients were diagnosed with acute mesenteric ischemia. CT, DPL, both, or neither was used to determine need for operative intervention for acute mesenteric ischemia. Primary outcomes were in-hospital mortality and operative intervention. The secondary outcome was time to operation. After adjusting for differences in case mix, DPL was associated with a reduced risk for operative intervention by comparison with CT (adjusted odds ratio [OR] = 0.04; 95% confidence interval [CI] 0.01 0.32) and with no preoperative intervention (adjusted OR = 0.05; 95% CI 0.01 0.28). DPL was associated with a reduced risk for death by comparison with those undergoing no operative evaluation (adjusted OR = 0.21; 95% CI 0.05 0.96) and those undergoing CT (adjusted OR = 0.09; 95% CI 0.01 0.62). There was no significant difference in time to operative intervention between those receiving DPL compared with CT (6.5 h vs. 29.9 h; p = 0.42). In conclusion, this study shows that DPL is associated with decreased operative intervention yet improved survival when compared with patients evaluated with either CT or no diagnostic modality for acute mesenteric ischemia in the ICU patient. Some limitations to this study are selection bias, in that there was significant concern for mesenteric ischemia in the enrolled patient population. The DPL cohort was significantly more ill, based on APACHE (Acute Physiology and Chronic Health Evaluation) II scores, which could lead to residual confounding or intervention bias. This study may not be generalizable to all patients in whom mesenteric ischemia is suspected,

263 as it was restricted to ICU patients with a mean APACHE II score of 21.7. [Justin Westphalen, MD Denver Health Medical Center, Denver, CO] Comment: Identifying acute mesenteric ischemia in the critically ill patient poses a diagnostic challenge. Accurate and expeditious diagnosis is necessary to proceed with lifesaving operative interventions, while avoiding unnecessary surgeries, which could add undue risk and harm to the patient. CT has limitations in this setting. DPL may be a helpful alternative for avoiding unnecessary operations in already critically ill patients when deemed unnecessary by a negative DPL. , CLEARED FOR TAKEOFF: THE EFFECTS OF HYPOBARIC CONDITIONS ON TRAUMATIC PNEUMOTHORACES. Majercik S, White T, Van Boerum D, et al. J Trauma Acute Care Surg 2014;77:729 33. Current medical guidelines state that traumatic pneumothorax (tPTX) is an absolute contraindication to commercial airline travel, and patients should wait at least 2 weeks after radiographic resolution of tPTX to fly. These guidelines are based on weak evidence. The objectives of this study were to determine if patients undergoing simulated flight conditions immediately after acute treatment for tPTX would experience any cardiopulmonary signs or symptoms or have radiographic enlargement of their pneumothorax. In this prospective observational study, 20 patients with tPTX recently treated by either tube thoracostomy or highflow oxygen were subjected to barometric pressure of 554 mm Hg in a hypobaric chamber, simulating 8400 feet in Phase 1 for 2 h or subjected to barometric pressure of 471 mm Hg in a hypobaric chamber simulating an altitude of 12,650 feet in Phase 2 for 2 h. Ten participants were included in each phase. Most commercial airplanes are pressurized to approximately 8000 feet. During the simulated flight, participants were asked about cardiopulmonary symptoms. Participants had chest xray studies performed at admission, within 6 h of entering the hypobaric chamber, in the hypobaric chamber at desired barometric pressure, and 4 h after completion of the study. In both phases, no participant had subjective or objective evidence of cardiopulmonary compromise. No participant required any invasive intervention during the study period. In Phase 1, tPTX size increased 122% at simulated altitude and 171% at simulated altitude in Phase 2. When returned to ambient altitude, the pneumothoraces decreased to baseline size. Although statistically significant, the expansion was not clinically significant. Some limitations to this study were the small sample size and small increase in barometric pressure in Phase 1, as the starting altitude was 4500 feet. All of the subjects in this study had small or no residual tPTX. In conclusion, this prospective observational study demonstrates that patients with a recently treated small tPTX can tolerate a simulated commercial airline flight without clinical