Direct Peritoneal Resuscitation in Trauma Patients Results in Similar Rates of Intra-Abdominal Complications.

Background: Trauma patients undergoing damage control surgery (DCS) have a propensity for complicated abdominal closures and intra-abdominal complications. Studies show that management of open abdomens with direct peritoneal resuscitation (DPR) reduces intra-abdominal complications and accelerates abdominal closure. This novel study compares intra-abdominal complication rates and the effect of DPR initiation in patients who received DPR and those who did not. Patients and Methods: A retrospective chart review was performed on 120 patients who underwent DCS. Fifty patients were identified as DCS with DPR, and matched to 70 controls by gender, race, age, body mass index (BMI), past medical history, mechanism of trauma, and injury severity score. Results: The two groups of patients, those without DPR (-DPR) and those with DPR (+DPR), were similar in their characteristics. The +DPR group was more likely to have a mesh closure than the -DPR (14% and 3%; p = 0.022). The +DPR group took longer to have a final closure (3.5 ± 2.6 days vs. 2.5 ± 1.8; p = 0.020). Infection complications and mechanical failure of the closure technique were similar among the two groups. Timing of DPR initiation had no effect on closure type but did statistically increase the number of days to closure (initiation at first operation 2.8 ± 1.8 days vs. initiation at subsequent operations 6.0 ± 3.3 days; p ≤ 0.001). Conclusions: The use of DPR did not result in different outcomes in trauma patients. Therefore, traditional resuscitative measures for DCS may not be inferior to DCS with DPR. When choosing to use DPR, initiating it at the first operation could reduce the number of days to closure.

Use of open and endovascular surgical techniques to manage vascular injuries in the trauma setting: A review of the American Association for the Surgery of Trauma PROspective Observational Vascular Injury Trial registry.

BACKGROUND: Vascular trauma data have been submitted to the American Association for the Surgery of Trauma PROspective Observational Vascular Injury Trial (PROOVIT) database since 2013. We present data to describe current use of endovascular surgery in vascular trauma. METHODS: Registry data from March 2013 to December 2016 were reviewed. All trauma patients who had an injury to a named artery, except the forearm and lower leg, were included. Arteries were grouped into anatomic regions and by compressible and noncompressible region for analysis. This review focused on patients with noncompressible transection, partial transection, or flow-limiting defect injuries. Bivariate and multivariate analyses were used to assess the relationships between study variables. RESULTS: One thousand one hundred forty-three patients from 22 institutions were included. Median age was 32 years (interquartile range, 23-48) and 76% (n = 871) were male. Mechanisms of injury were 49% (n = 561) blunt, 41% (n = 464) penetrating, and 1.8% (n = 21) of mixed aetiology. Gunshot wounds accounted for 73% (n = 341) of all penetrating injuries. Endovascular techniques were used least often in limb trauma and most commonly in patients with blunt injuries to more than one region. Penetrating wounds to any region were preferentially treated with open surgery (74%, n = 341/459). The most common indication for endovascular treatment was blunt noncompressible torso injuries. These patients had higher Injury Severity Scores and longer associated hospital stays, but required less packed red blood cells, and had lower in hospital mortality than those treated with open surgery. On multivariate analysis, admission low hemoglobin concentration and abdominal injury were independent predictors of mortality. CONCLUSION: Our review of PROOVIT registry data demonstrates a high utilization of endovascular therapy among severely injured blunt trauma patients primarily with noncompressible torso hemorrhage. This is associated with a decreased need for blood transfusion and improved survival despite longer length of stay. LEVEL OF EVIDENCE: Therapeutic/care management, level III.

Systemic anticoagulation in the setting of vascular extremity trauma.

INTRODUCTION: There is conflicting data regarding if patients with vascular extremity trauma who undergo surgical treatment need to be systematically anticoagulated. We hypothesized that intraoperative systemic anticoagulation (ISA) decreased the risk of repair thrombosis or limb amputation after traumatic vascular injury of the extremities. METHODS: We analyzed a composite risk of repair thrombosis and/or limb amputation (RTLA) between patients who did and did not undergo ISA during arterial injury repair. Patient data was collected in the American Association for the Surgery of Trauma PROspective Vascular Injury Treatment (PROOVIT) registry. This registry contains demographic, diagnostic, treatment, and outcome data. RESULTS: Between February 2013 and August 2015, 193 patients with upper or lower extremity arterial injuries who underwent open operative repair were entered into the PROOVIT registry. The majority were male (87%) with a mean age of 32.6 years (range 4-91) and 74% injured by penetrating mechanism. 63% of the injuries were described as arterial transection and 37% had concomitant venous injury. 62% of patients underwent ISA. RTLA occurred in 22 patients (11%) overall, with no significant difference in these outcomes between patients who received ISA and those that did not (10% vs. 14%, p=0.6). There was, however, significantly higher total blood product use noted among patients treated with ISA versus those that did not receive ISA (median 3 units vs. 1 unit, p=0.002). Patients treated with ISA also stayed longer in the ICU (median 3days vs. 1day, p=0.001) and hospital (median 9.5days vs. 6days, p=0.01). DISCUSSION: In this multicenter prospective cohort, intraoperative systemic anticoagulation was not associated with a difference in rate of repair thrombosis or limb loss; but was associated with an increase in blood product requirements and prolonged hospital stay. Our data suggest there is no significant difference in outcome to support use of ISA for repair of traumatic arterial injuries.

The AAST prospective Aortic Occlusion for Resuscitation in Trauma and Acute Care Surgery (AORTA) registry: Data on contemporary utilization and outcomes of aortic occlusion and resuscitative balloon occlusion of the aorta (REBOA).

INTRODUCTION: Aortic occlusion (AO) for resuscitation in traumatic shock remains controversial. Resuscitative endovascular balloon occlusion of the aorta (REBOA) offers an emerging alternative. METHODS: The American Association for the Surgery of Trauma Aortic Occlusion for Resuscitation in Trauma and Acute Care Surgery registry prospectively identified trauma patients requiring AO from eight ACS Level 1 centers. Presentation, intervention, and outcome variables were collected and analyzed to compare REBOA and open AO. RESULTS: From November 2013 to February 2015, 114 AO patients were captured (REBOA, 46; open AO, 68); 80.7% were male, and 62.3% were blunt injured. Aortic occlusion occurred in the emergency department (73.7%) or the operating room (26.3%). Hemodynamic improvement after AO was observed in 62.3% [REBOA, 67.4%; open OA, 61.8%); 36.0% achieving stability (systolic blood pressure consistently >90 mm Hg, >5 minutes); REBOA, 22 of 46 (47.8%); open OA, 19 of 68 (27.9%); p =0.014]. Resuscitative endovascular balloon occlusion of the aorta (REBOA) access was femoral cut-down (50%); US guided (10.9%) and percutaneous without imaging (28.3%). Deployment was achieved in Zones I (78.6%), II (2.4%), and III (19.0%). A second AO attempt was required in 9.6% [REBOA, 2 of 46 (4.3%); open OA, 9 of 68 (13.2%)]. Complications of REBOA were uncommon (pseudoaneurysm, 2.1%; embolism, 4.3%; limb ischemia, 0%). There was no difference in time to successful AO between REBOA and open procedures (REBOA, 6.6 ± 5.6 minutes; open OA, 7.2 ± 15.1; p = 0.842). Overall survival was 21.1% (24 of 114), with no significant difference between REBOA and open AO with regard to mortality [REBOA, 28.2% (13 of 46); open OA, 16.1% (11 of 68); p = 0.120]. CONCLUSION: Resuscitative endovascular balloon occlusion of the aorta has emerged as a viable alternative to open AO in centers that have developed this capability. Further maturation of the American Association for the Surgery of Trauma Aortic Occlusion for Resuscitation in Trauma and Acute Care Surgery database is required to better elucidate optimal indications and outcomes. LEVEL OF EVIDENCE: Therapeutic/care management study, level IV.

Ventilator-Associated Pneumonia in Trauma Patients: Different Criteria, Different Rates.

BACKGROUND: No consensus exists regarding the definition of ventilator-associated pneumonia (VAP). Even within a single institution, inconsistent diagnostic criteria result in conflicting rates of VAP. As a Level 1 trauma center participating in the Trauma Quality Improvement Project (TQIP) and the National Healthcare Safety Network (NHSN), our institution showed inconsistencies in VAP rates depending on which criteria was applied. The purpose of this study was to compare VAP definitions, defined by culture-based criteria, National Trauma Data Bank (NTDB) and NHSN, using incidence in trauma patients. METHODS: A retrospective chart review of consecutive trauma patients who were diagnosed with VAP and met pre-determined inclusion and exclusion criteria admitted to our rural, 861-bed, Level 1 trauma and tertiary care center between January 2008 and December 2011 was performed. These patients were identified from the National Trauma Registry of the American College of Surgeons (NTRACS) database and an in-house infection control database. Ventilator-associated pneumonia diagnosis criteria defined by the U.S. Center for Disease Control and Prevention (used by the NHSN), the NTDB, and our institutional, culture-based criteria gold standard were compared among patients. RESULTS: Two hundred seventy-nine patients were diagnosed with VAP (25.4% met NHSN criteria, 88.2% met NTDB, and 76.3% met culture-based criteria). Only 58 (20.1%) patients met all three criteria. When NHSN criteria were compared with culture-based criteria, NHSN showed a high specificity (92.5%) and low sensitivity (28.2%). The positive predictive value (PPV) was 84.5%, but the negative predictive value (NPV) was 47.1%. The agreement between the NHSN and the culture-based criteria was poor (κ = 0.18). Conversely, the NTDB showed a lower specificity (57.8%), but greater sensitivity (86.4%) compared with culture-based criteria. The PPV and NPV were both 74% and the two criteria showed fair agreement (κ = 0.41). CONCLUSIONS: The lack of standard diagnostic criteria for VAP resulted in variable reporting to different agencies. Emphasis on establishing a consensus VAP definition should be undertaken.

Lung protective ventilation (ARDSNet) versus airway pressure release ventilation: ventilatory management in a combined model of acute lung and brain injury.

BACKGROUND: Concomitant lung/brain traumatic injury results in significant morbidity and mortality. Lung protective ventilation (Acute Respiratory Distress Syndrome Network [ARDSNet]) has become the standard for managing adult respiratory distress syndrome; however, the resulting permissive hypercapnea may compound traumatic brain injury. Airway pressure release ventilation (APRV) offers an alternative strategy for the management of this patient population. APRV was hypothesized to retard the progression of acute lung/brain injury to a degree greater than ARDSNet in a swine model. METHODS: Yorkshire swine were randomized to ARDSNet, APRV, or sham. Ventilatory settings and pulmonary parameters, vitals, blood gases, quantitative histopathology, and cerebral microdialysis were compared between groups using χ2, Fisher's exact, Student's t test, Wilcoxon rank-sum, and mixed-effects repeated-measures modeling. RESULTS: Twenty-two swine (17 male, 5 female), weighing a mean (SD) of 25 (6.0) kg, were randomized to APRV (n = 9), ARDSNet (n = 12), or sham (n = 1). PaO2/FIO2 ratio dropped significantly, while intracranial pressure increased significantly for all three groups immediately following lung and brain injury. Over time, peak inspiratory pressure, mean airway pressure, and PaO2/FIO2 ratio significantly increased, while total respiratory rate significantly decreased within the APRV group compared with the ARDSNet group. Histopathology did not show significant differences between groups in overall brain or lung tissue injury; however, cerebral microdialysis trends suggested increased ischemia within the APRV group compared with ARDSNet over time. CONCLUSION: Previous studies have not evaluated the effects of APRV in this population. While our macroscopic parameters and histopathology did not observe a significant difference between groups, microdialysis data suggest a trend toward increased cerebral ischemia associated with APRV over time. Additional and future studies should focus on extending the time interval for observation to further delineate differences between groups.

When birds can't fly: an analysis of interfacility ground transport using advanced life support when helicopter emergency medical service is unavailable.

BACKGROUND: Helicopter emergency medical service (HEMS) transport of trauma patients is costly and of unproven benefit. Recent retrospective studies fail to control for crew expertise and therefore compare highly trained advance life support with less-trained basic life support crews. The purpose of our study was to compare HEMS with ground, interfacility transport while controlling for crew training. We hypothesized that patients transported by HEMS would experience shorter interhospital transport time and reduced mortality. METHODS: Our National Trauma Registry of the American College of Surgeons database was retrospectively queried to identify consecutive interfacility, hospital transfers (January 1, 2008, to November 1, 2012) to our Level I trauma center. Transfers were stratified by transportation vehicle (i.e., HEMS vs. ground transport). Cohorts were compared across standard demographic and clinical variables using univariate analysis. Multivariate logistic regression was performed to determine the association of these variables with mortality. RESULTS: The HEMS (n = 2,190) and ground (n = 223) cohorts were well matched overall, with no significant differences for demographics, injury severity, physiology, hospital length of stay, or complications. Median (interquartile range) time to definitive care was significantly lower for HEMS (150 [114] minutes vs. 255 [157] minutes, p < 0.001), without change in mortality (9.0% vs. 8.1%, p = 0.71). Multivariate logistic regression did not identify an association between transport mode and mortality. CONCLUSION: Despite faster interfacility transport times, HEMS offered no mortality benefit compared with ground when crew expertise was controlled for, contradicting recent large, retrospective National Trauma Data Bank studies. Our study may represent the best approximation of a prospective study by focusing on patients deemed worthy of HEMS by referring providers. Although HEMS may seem intuitively beneficial for time-dependent injuries, larger studies with a similar methodology are warranted to justify the cost and risk of HEMS and identify subsets of patients who may benefit. LEVEL OF EVIDENCE: Prognostic/epidemiologic study, level III.

Transcriptional up-regulation and activation of initiating caspases in experimental glaucoma.

In glaucoma, retinal ganglion cells (RGCs) die by apoptosis, generally attributed to an elevated intraocular pressure (IOP). We now describe the impact of elevated IOP in the rat on expression of caspase 8 and caspase 9, initiators of the extrinsic and intrinsic caspase cascades, respectively. Activation of both caspases was demonstrated by the presence of cleaved forms of the caspases and the detection of cleaved Bid and PARP, downstream consequences of caspase activation. Surprisingly, the absolute level of procaspase 9 was also elevated after 10 days of increased IOP. To examine the cause of increased levels of the procaspase, we used laser capture microdissection to capture Fluorogold back-labeled RGCs and real-time polymerase chain reaction to measure mRNA changes of initiating caspases. The mRNA levels of both caspase 8 and caspase 9 were increased specifically in RGCs. These data suggest that elevated IOP activates a transcriptional up-regulation and activation of initiating caspases in RGCs and triggers apoptosis through both extrinsic and intrinsic caspase cascades.

FK506 blocks activation of the intrinsic caspase cascade after optic nerve crush.

Retinal ganglion cells die by apoptosis after optic nerve crush. FK506 has been shown to be neuroprotective in this model but the mechanism(s) by which it exerts these actions remains unknown. We and others have shown that caspase 9 is cleaved in the retina in other injury models and we hypothesized that the neuroprotection observed with FK506 was mediated by interference with caspase 9 activation. The present study examined the cellular localization of caspase 9 cleavage after intraorbital optic nerve crush in rats, the time course of caspase 9 cleavage after optic nerve crush and the ability of orally administered FK506 to block caspase 9 cleavage after optic nerve crush. We show by immunohistochemistry that cleaved caspase 9 is present in retinal ganglion cells (identified by prior backlabelling) after optic nerve crush. Immunoblot analysis showed that caspase 9 cleavage is significantly elevated 5 and 8 days after optic nerve crush. We show that orally administered FK506 reaches the retina and is pharmacologically active in retinal tissue. Furthermore, the oral administration of FK506 5 mg kg(-1) day(-1) blocks the cleavage of caspase 9 at both time points. These data suggest that caspase 9 activation may play an important role in retinal ganglion cell death following optic nerve crush and that the neuroprotection seen with FK506 may be mediated by interfering with the activation of caspase 9.

Activation of caspase 9 in a rat model of experimental glaucoma.

PURPOSE: We investigated retinal ganglion cell (RGC) death and activation of caspase 9 in rats with experimental glaucoma. METHODS: Elevated intraocular pressure (IOP) was induced in rats using the Morrison model. Surviving backlabeled RGC were counted and TUNEL staining detected apoptosis. Procaspase 9 expression and activated caspase 9 were studied by immunoblot and immunohistochemistry. RESULTS: IOP correlated with surviving RGC. TUNEL-positive RGC were observed in animals with elevated IOP. Procaspase 9 levels increased with IOP intensity. Cleaved caspase 9 was detected by immunoblot only in rats with peak IOP above 35 mm Hg for > or =6 days. Cleaved caspase 9 staining was seen only in the ganglion cell layer of retinas from rats with peak IOP > or =32 mm Hg. CONCLUSIONS: RGC loss is correlated with IOP in experimental glaucoma. These results support activation of caspase 9, the intrinsic caspase cascade, in RGC death in experimental glaucoma.