Evaluating for acute mesenteric ischemia in critically ill patients: diagnostic peritoneal lavage is associated with reduced operative intervention and mortality.

BACKGROUND: The diagnosis of acute mesenteric ischemia among intensive care unit (ICU) patients continues to be difficult and carries high mortality, and yet, it is essential that it be made expeditiously such that lifesaving operative intervention can be offered. A recent study suggested that computed tomography (CT) scan delays operative intervention. Thus, we hypothesized that diagnostic peritoneal lavage (DPL), a rapidly performed bedside procedure of established high sensitivity, is associated with reduced operative intervention, time to operative intervention, and mortality. METHODS: We performed a single-institution, retrospective study of 120 patients admitted to an ICU at the University of Pittsburgh Medical Center's Presbyterian Hospital between January 1, 2002, and December 31, 2010, who were diagnosed with acute mesenteric ischemia. We defined a DPL of greater than 500 cells per cubic millimeter as diagnostic of intra-abdominal pathology. CT scan results were categorized as (1) diagnostic of mesenteric ischemia, (2) abnormal, or (3) normal. We performed multivariate logistic regression, adjusting for difference in case mix, to determine whether DPL is associated with the outcomes of mortality and operative intervention. RESULTS: The cohort was severely ill, with a mean Acute Physiology and Chronic Health Evaluation II (APACHE II) score of 21.7 (range, 0-48), and 51 patients (42.5%) died. The distribution of preoperative evaluation is as follows: CT, 67; DPL, 11; both modalities, 18; and no preoperative evaluation, 24. Those undergoing DPL were more severely ill, as evidenced by significantly higher APACHE II scores. By comparison with CT, DPL was associated with a reduced risk for operation intervention (adjusted odds ratio, 0.04; 95% confidence interval, 0.01-0.32; p = 0.002) and mortality (adjusted odds ratio, 0.09; 95% confidence interval, 0.01-0.62; p = 0.02). CONCLUSION: DPL is associated with reduced operative intervention yet improved survival, when compared with patients evaluated with either CT or no diagnostic modality. These data support that, for critically ill ICU patients suspected of harboring intra-abdominal pathology such as acute mesenteric ischemia, DPL should be a mainstay in the preoperative diagnostic evaluation. Further investigation is needed, however, to better define the proper place and timing of DPL in evaluating the acute abdomen. LEVEL OF EVIDENCE: Diagnostic study, level III; therapeutic/care management study, level IV.

Persistence of elevated plasma CXCL8 concentrations following red blood cell transfusion in a trauma cohort.

Red blood cell (RBC) transfusion is associated with alterations in systemic concentrations of IL-8/CXCL8 functional homologs in a murine model. Whether RBC transfusion alters systemic neutrophil chemokine concentrations in individuals sustaining traumatic injury is not known. We conducted a retrospective, single-center study of severely injured trauma patients presenting within 12 h of injury with a base deficit greater than 6 and hypotension in the field. Plasma concentrations of 25 chemokines, cytokines, and growth factors were obtained from both transfused (n = 22) and nontransfused (n = 33) groups in the first 48 h following admission. The transfused group (mean RBC units, 2.7 [SD, 1.7]) tended to be older (49.9 [SD, 21.1] vs. 40.4 [SD, 19.9] years, P = 0.10), with a higher percentage of females (40.9% vs. 18.2%, P = 0.06) and a higher Injury Severity Score (27.1 [SD, 12.7] vs. 21.4 [SD, 10.2], P = 0.07). In univariate and multivariate analyses, transfusion was associated with increased hospital and intensive care unit length of stay but not ventilator-free days. Plasma CXCL8 concentrations were higher in the transfused (84 [SD, 88] pg/mL) than the nontransfused group (31 [SD, 21] pg/mL, P = 0.003). Using a linear prediction model to calculate bioanalyte concentrations standardized for age, sex, Injury Severity Score, and admission SBP, we observed that CXCL8 concentrations diverged within 12 h following injury, with the transfused group showing persistently elevated CXCL8 concentrations by contrast to the decay observed in the nontransfused group. Other bioanalytes showed no differences across time. Red blood cell transfusion is associated with persistently elevated neutrophil chemokine CXCL8 concentrations following traumatic injury.