Gender-based differences in mortality in response to high product ratio massive transfusion.

BACKGROUND: Recent data suggest that patients undergoing massive transfusion have lower mortality rates when ratios of plasma and platelets to red blood cells (RBCs) of ≥ 1:2 are used. This has not been examined independently in women and men. A gender dichotomy in outcome after severe injury is known to exist. This study examined gender-related differences in mortality after high product ratio massive transfusion. METHODS: A retrospective study was conducted using a database containing massively transfused trauma patients from 23 Level I trauma centers. Baseline demographic, physiologic, and biochemical data were obtained. Univariate and logistic regression analyses were performed. Adjusted mortality in patients receiving high (≥ 1:2) or low (<1:2) ratios of plasma or platelets to RBCs was compared in women and men independently. RESULTS: Seven hundred four patients were analyzed. In males, mortality was lower for patients receiving a high plasma:RBC ratio at 24 hours (20.6% vs. 33.0% for low ratio, p = 0.005) and at 30 days (34.9% vs. 42.8%, p = 0.032). Males receiving a high platelet:RBC ratio also had lower 24-hour mortality (17.6% vs. 31.5%, p = 0.004) and 30-day mortality (32.1% vs. 42.2%, p = 0.045). Females receiving high ratios of plasma or platelets to RBCs had no improvement in 24-hour mortality (p = 0.119 and 0.329, respectively) or 30-day mortality (p = 0.199 and 0.911, respectively). Use of high product ratio transfusions did not affect 24-hour RBC requirements in males or females. CONCLUSION: Use of high plasma:RBC or platelet:RBC ratios in massive transfusion may benefit men more than women. This may be due to gender-related differences in coagulability. Further study is needed to determine whether separate protocols for women and men should be established.

An evaluation of multidetector computed tomography in detecting pancreatic injury: results of a multicenter AAST study.

BACKGROUND: Efforts to determine the suitability of low-grade pancreatic injuries for nonoperative management have been hindered by the inaccuracy of older computed tomography (CT) technology for detecting pancreatic injury (PI). This retrospective, multicenter American Association for the Surgery of Trauma-sponsored trial examined the sensitivity of newer 16- and 64-multidetector CT (MDCT) for detecting PI, and sensitivity/specificity for the identification of pancreatic ductal injury (PDI). METHODS: Patients who received a preoperative 16- or 64-MDCT followed by laparotomy with a documented PI were enrolled. Preoperative MDCT scans were classified as indicating the presence (+) or absence (-) of PI and PDI. Operative notes were reviewed and all patients were confirmed as PI (+), and then classified as PDI (+) or (-). As all patients had PI, an analysis of PI specificity was not possible. PI patients formed the pool for further PDI analysis. As sensitivity and specificity data were available for PDI, multivariate logistic regression was performed for PDI patients using the presence or absence of agreement between CT and operative note findings as an independent variable. Covariates were age, gender, Injury Severity Score, mechanism of injury, presence of oral contrast, presence of other abdominal injuries, performance of the scan as part of a dedicated pancreas protocol, and image thickness < or =3 mm or > or =5 mm. RESULTS: Twenty centers enrolled 206 PI patients, including 71 PDI (+) patients. Intravenous contrast was used in 203 studies; 69 studies used presence of oral contrast. Eight-nine percent were blunt mechanisms, and 96% were able to have their duct status operatively classified as PDI (+) or (-). The sensitivity of 16-MDCT for all PI was 60.1%, whereas 64-MDCT was 47.2%. For PDI, the sensitivities of 16- and 64-MDCT were 54.0% and 52.4%, respectively, with specificities of 94.8% for 16-MDCT scanners and 90.3% for 64-MDCT scanners. Logistic regression showed that no covariates were associated with an increased likelihood of detecting PDI for either 16- or 64-MDCT scanners. The area under the curve was 0.66 for the 16-MDCT PDI analysis and 0.77 for the 64-MDCT PDI analysis. CONCLUSION: Sixteen and 64-MDCT have low sensitivity for detecting PI and PDI, while exhibiting a high specificity for PDI. Their use as decision-making tools for the nonoperative management of PI are, therefore, limited.

Ketamine-based total intravenous anesthesia versus isoflurane anesthesia in a swine model of hemorrhagic shock.

BACKGROUND: Inhalational anesthetics can cause profound hemodynamic effects including decreases in systemic vascular resistance and cardiac inotropy. Although widely used in uncontrolled hemorrhagic shock (UHS), their consequences compared with other anesthetic regimens are not well-studied. Ketamine-based total intravenous anesthesia (TIVA) may produce less profound cardiovascular depression, and has been used during elective surgery but rarely during traumatic shock. The purpose of this study was to compare the effects of isoflurane (ISO) and TIVA regimens in a swine grade V liver injury model. We hypothesized that TIVA would result in less hypotension and dysfunctional inflammation than ISO. METHODS: Twenty swine were randomized blindly to receive either 1% to 3% ISO, or intravenous ketamine, midazolam, and buprenorphine for maintenance anesthesia. Six animals acted as controls. After sedation and intubation, randomized anesthesia was initiated and monitored by an independent animal technician. Invasive lines were placed followed by celiotomy and splenectomy. Baseline mean arterial pressure (MAP) was documented and a grade V liver injury created. After 30 minutes of UHS, animals were resuscitated with 8 mL of Ringer's lactate per milliliter blood loss at 165 mL/min. MAP and tissue oxygen saturation (StO2) were continuously recorded. The animals were sacrificed 120 minutes after injury and lung tissue was harvested. Serum cytokines (interleukin-6 [IL-6], IL-8, and tumor necrosis factor-alpha [TNF-alpha]) were quantified with enzyme-linked immunosorbent assay. Lung cytokine mRNA levels were quantified with real time reverse transcriptase polymerase chain reaction. RESULTS: Animal weight, liver injury pattern, and blood loss were similar (p > 0.1). The ISO group had a lower MAP at baseline (p = 0.02), at injury (p = 0.004), and study completion (p = 0.001). After resuscitation, MAP decreased in the ISO group but remained stable in the TIVA group. StO2 was significantly higher in the TIVA group immediately after injury (p = 0.004), but similar between groups throughout the remainder of the study. Animals who received TIVA trended toward higher levels of lactate and lower pH throughout the study, reaching significance at 30 minutes postinjury (p = 0.037 and 0.043). Inflammatory cytokine (IL-6, IL-8, and TNF-alpha) production did not differ between groups, however TNF-alpha mRNA production was significantly lower in the TIVA group (p = 0.04). CONCLUSION: Although a TIVA regimen produced less pronounced hypotension in a swine model of UHS than did ISO, end-organ perfusion with TIVA appeared to be equivalent or inferior to ISO. In circumstances of limited resources, such as those experienced by forward Army surgical teams, a ketamine-based TIVA regimen may be an option for use in UHS.

Battlefield trauma, traumatic shock and consequences: war-related advances in critical care.

Over the course of history, while the underlying causes for wars have remained few, mechanisms of inflicting injury and our ability to treat the consequent wounds have dramatically changed. Success rates in treating war-related injuries have improved greatly, although the course of progress has not proceeded linearly. From Homer's Iliad to the Civil War to Vietnam, there have been significant improvements in mortality, despite a concurrent increase in the lethality of weapons. These improvements have occurred primarily as a result of progress in three key areas: management of wounds, treatment of shock, and systems of organization.