Trauma readiness training for military deployment: a comparison between a U.S. trauma center and an Air Force Theater Hospital in Balad, Iraq.

The U.S. Air Force created the Center for Sustainment of Trauma and Readiness Skills at the Shock Trauma Center (STC) where staffs rotate before deployment. We sought to investigate the value of this training. A retrospective review of prospectively collected data of patient volume, injury severity, mechanism of injury, operative cases, and massive transfusion data from September 2006 to August 2007 was obtained from the STC in Baltimore and the Air Force Theater Hospital (AFTH) in Balad. Severity of injury and massive transfusions were higher at the AFTH. Soft tissue wound care represented approximately 25% of AFTH cases; a soft tissue service performed 465 operative debridements for severe soft tissue infections at STC. The STC's high-volume of major soft tissue debridement cases may offer the closest approximation of high energy wound care. Training at selected U.S. trauma centers may prepare military staff to care for war injuries, particularly those who do not practice in high-volume Level 1 trauma centers.

Accuracy of computed tomography (CT) scan in the detection of penetrating diaphragm injury.

BACKGROUND: The use of computed tomography (CT) to identify injury after penetrating torso trauma has become routine in the hemodynamically stable patient. The diaphragm has been a historically difficult structure to evaluate, however, and missed injuries to the diaphragm may result in significant morbidity. With the increasing use of multidetector row CT (MDCT), we hypothesized that CT would be an accurate detection modality to identify patients with diaphragm injuries. METHODS: We retrospectively reviewed the admission CT of consecutive patients admitted for penetrating injury to the torso during a 4-year period. The CT scans were reviewed and classified into three categories: positive (P), negative (N), or equivocal (Eq). Data from the medical records of these patients were abstracted to identify demographics, injury-specific data, length of stay, length of follow-up (LOFU), and operative findings. RESULTS: There were 803 patients who met inclusion criteria. Mechanism of injury was gunshot wound in 36% and stab wound in 64%. Mean length of stay was 4 days (+/-6.6) and mean length of follow-up was 43 days (+/-184). CT was read as P in 57, N in 710, and Eq in 36 patients. Diaphragm injury was detected in 67 patients overall and was excluded in 736. For the entire study population, sensitivity and specificity were calculated as 94.0% (95% CI = 88.4-99.7) and 95.9% (94.5-97.4) with an overall accuracy of 95.8% (94.4-97.2) if the CT scan was used to exclude diaphragm injury ([P and Eq] vs. N). Sensitivity and specificity were 82.1% (72.9-91.3) and 99.7% (99.4-100) if CT was used to detect diaphragm injury (P vs. [N and Eq]). One hundred and forty-eight patients underwent operative procedures in which the diaphragm was evaluated. Diaphragm injury was identified in 50 (38 P, 4 N, 8 Eq) and was surgically excluded in 104 patients (2 P, 93 N, 9 Eq). Three hundred and eighty-four patients were lost to follow-up; including 348 who had negative finding on CT. There were no known missed diaphragm injuries during the study period or in follow-up. CONCLUSIONS: Injuries to the diaphragm occur commonly after penetrating torso trauma. MDCT scan is an accurate test to detect diaphragm injury. When MDCT is equivocal, further investigation is required to evaluate the diaphragm.

Resuscitation from hemorrhagic shock comparing standard hemoglobin-based oxygen carrier (HBOC)-201 versus 7.5% hypertonic HBOC-201.

BACKGROUND: Hemoglobin-based oxygen carrier (HBOC) resuscitation has been associated with increased systemic and pulmonary vascular resistances (SVR, PVR), which may result in reduced blood flow and severe pulmonary hypertension. The physiologic and immunologic properties of 7.5% hypertonic saline solution (HTS), such as reduction of SVR and PVR, as well as inhibition of neutrophil and endothelial activation may be beneficial in reducing some of these undesirable effects of HBOCs. The aim of this study was to evaluate the hemodynamic effects of the HBOC and HBOC-201 suspended in 7.5% hypertonic saline solution (HT-HBOC) when compared with standard HBOC resuscitation. METHODS: Thirty-two domestic crossbred pigs (50-60 kg) were hemorrhaged to a mean arterial pressure (MAP) of 35 mm Hg +/- 5 mm Hg for 45 minutes and resuscitated to a baseline mean arterial pressure using the following groups: (1) sham, no hemorrhage; (2) shed blood + lactated Ringer's solution; (3) standard HBOC-201; (4) hypertonic saline 7.5%; (5) hypertonic 7.5% HBOC-201. After resuscitation, observation was continued for 4 hours. Hemodynamic variables, oxygen consumption, and arterial blood gases were monitored continuously. Data were analyzed using analysis of variance. RESULTS: SVR (p = 0.001), PVR (p = 0.001), and MPAP (p = 0.01) were significantly reduced in the HT-HBOC group compared with the standard HBOC group. CONCLUSION: In this model of hemorrhagic shock, hypertonic HBOC-201- resuscitated pigs had significantly reduced SVR and PVR, as well as mean pulmonary artery pressure (MPAP) and increased cardiac output. HT-HBOC may be beneficial in reducing the undesirable effects of standard HBOC-201. The mechanisms of these beneficial effects need to be investigated.

Low-volume resuscitation with a polymerized bovine hemoglobin-based oxygen-carrying solution (HBOC-201) provides adequate tissue oxygenation for survival in a porcine model of controlled hemorrhage.

BACKGROUND: We have shown in a previous work that HBOC-201 is able to reverse anaerobic metabolism at low volumes in a porcine model of controlled hemorrhage. On the basis of these results, we hypothesize that low-volume resuscitation with HBOC-201 in a porcine model of controlled hemorrhage provides adequate tissue oxygenation to limit end-organ damage and allow for survival of the animal. METHODS: Twenty-four Yorkshire swine (55-65 kg) were rapidly hemorrhaged to a mean arterial pressure (MAP) of 30 mm Hg, maintained hypotensive for 45 minutes, and then divided into four groups. The first group, Shed Blood (BL), was resuscitated with shed blood to baseline MAP. A second group, Shed Blood (60), underwent resuscitation for four hours at an MAP of 60 mm Hg with shed blood. The third group, LR + Blood, was resuscitated with lactated Ringer's (maximum, 40 mL/kg) followed by shed blood to baseline MAP. The final group, HBOC (60), underwent resuscitation for 4 hours at an MAP of 60 mm Hg with HBOC-201. Hemodynamic variables, urine output, blood gas analyses, lactate levels, and jejunal oximetry were followed throughout the experiment. Animals were allowed to survive and underwent necropsy on postinjury day 3. Histologic comparisons were made. Data were analyzed using analysis of variance/Duncan's multiple range test. RESULTS: All animals survived the hemorrhage/resuscitation. One animal in the LR + Blood group died on postinjury day 1. Heart rate, MAP, and arterial pH were similar between groups. Cardiac output was significantly lower throughout resuscitation in the HBOC (60) group. Jejunal oximetry was similar throughout the experiment in all groups, revealing a decline in Po2 during hemorrhage and return to baseline or near baseline during resuscitation. There was no evidence of renal dysfunction. Histologically, one animal in the LR + Blood group and four of six animals in the HBOC (60) group demonstrated mild hepatocellular damage. All other tissues examined were found to have no significant abnormalities. Elevations in serum aspartate aminotransferase levels were noted when comparing the HBOC (60) group to the Shed Blood (BL) and Shed Blood (60) groups on day 2. Significant decreases in hemoglobin levels were noted in the HBOC (60) group compared with all other groups beginning on day 2. CONCLUSION: Low-volume resuscitation with HBOC-201 provides adequate tissue oxygenation for survival in a porcine model of controlled hemorrhagic shock with no long-term organ dysfunction identified. Although some animals did show mild hepatocellular damage with elevations of aspartate aminotransferase at day 2, these findings did not appear to have clinical relevance, and the enzyme elevations were trending toward normal by the third postoperative day. Decreases in hemoglobin levels at the later time points were expected, given the half-life of the product.

Extracorporeal membrane oxygenation in piglets using a polymerized bovine hemoglobin-based oxygen-carrying solution (HBOC-201).

PURPOSE: The purpose of this study was to determine if the polymerized bovine hemoglobin-based oxygen-carrying solution HBOC-201 is an acceptable substitute for blood in a healthy porcine, extracorporeal membrane oxygenation (ECMO) model. METHODS: Ten piglets (15 to 25 kg) were placed on venoarterial ECMO. Four animals received blood-primed ECMO, and 6 animals received HBOC-201-primed ECMO. Hemodynamic variables, urine output, blood gas analyses, complete blood counts, and lactate levels were followed for 6 hours. Data were analyzed using a nonparametric sign test and repeated measures analysis of variance (ANOVA). RESULTS: All animals survived the 6-hour ECMO procedure. Heart rate, mean arterial pressure, urine output, and serum lactate levels were not significantly different between groups. Postpriming volume was 176 +/- 156 mL in the blood group. None of the animals in the HBOC-201 group required additional volume to maintain target flow during ECMO (P <.05). Arterial pH, pO2, and oxygen content between groups were not significantly different. Hematocrit for the HBOC-201 group was significantly (P <.05) lower than the blood group. CONCLUSIONS: HBOC-201-primed ECMO in a healthy porcine model showed similar hemodynamics and equivalent oxygen carrying capacity to blood-primed ECMO. Postpriming volume requirement was decreased significantly in the HBOC group. ECMO using HBOC-201 instead of blood appears promising and warrants further investigation.