Brandon R. Bruns

Blunt traumatic occult pneumothorax: is observation safe?--results of a prospective, AAST multicenter study.

BACKGROUND An occult pneumothorax (OPTX) is found incidentally in 2% to 10% of all blunt trauma patients. Indications for intervention remain controversial. We sought to determine which factors predicted failed observation in blunt trauma patients. METHODS A prospective, observational, multicenter study was undertaken to identify patients with OPTX. Successfully observed patients and patients who failed observation were compared. Multivariate logistic regression was used to identify predictors of failure of observation. OPTX size was calculated by measuring the largest air collection along a line perpendicular from the chest wall to the lung or mediastinum. RESULTS Sixteen trauma centers identified 588 OPTXs in 569 blunt trauma patients. One hundred twenty-one patients (21%) underwent immediate tube thoracostomy and 448 (79%) were observed. Twenty-seven patients (6%) failed observation and required tube thoracostomy for OPTX progression, respiratory distress, or subsequent hemothorax. Fourteen percent (10 of 73) failed observation during positive pressure ventilation. Hospital and intensive care unit lengths of stay, and ventilator days were longer in the failed observation group. OPTX progression and respiratory distress were significant predictors of failed observation. Most patient deaths were from traumatic brain injury. Fifteen percentage of patients in the failed observation group developed complications. No patient who failed observation developed a tension PTX, or experienced adverse events by delaying tube thoracostomy. CONCLUSION Most blunt trauma patients with OPTX can be carefully monitored without tube thoracostomy; however, OPTX progression and respiratory distress are independently associated with observation failure.

Prehospital hypotension redefined.

BACKGROUND The American College of Surgeons Committee on Trauma suggests prehospital systolic blood pressure (PSBP) < 90 mm Hg as a criterion for triage of injured patients to trauma centers. However, Advanced Trauma Life Support recognizes this threshold as a late sign of shock. We undertook the current study to determine whether a higher PSBP threshold may identify patients at significant risk of death. METHODS A retrospective analysis of an urban, Level I trauma center registry data was undertaken in patients with complete information on PSBP (n = 16,365; 1994-2003). Several thresholds of PSBP were chosen: < or = 60, < or = 70, < or = 80, < or = 90, < or = 100, and < or = 110 mm Hg, and the relationship between each threshold of PSBP and patient outcomes was explored. A p value < 0.05 was considered statistically significant. RESULTS Mean age of patients was 36 +/- 16 years, and 81% sustained a blunt injury. PSBP strongly correlated with systolic blood pressure obtained in the emergency department (Pearson r 0.65, p < 0.001). The risk of death increased sharply when PSBP dropped < 110 mm Hg, with nearly 1 in 10 (8%) dying in the emergency department and one in six (15%) dying eventually. CONCLUSIONS The definition of prehospital hypotension used for triage of injured patients to trauma centers should be redefined as PSBP < 110 mm Hg. The impact of this redefinition on trauma center resource utilization should be studied further.

Blunt cerebrovascular injury screening guidelines: what are we willing to miss?

BACKGROUND Blunt cerebrovascular injury (BCVI) is reported to occur in approximately 2% of blunt trauma patients, with a stroke rate of up to 20%. Guidelines for BCVI screening are based on clinical and radiographic findings. We hypothesized that liberal screening of the neck vasculature, as part of initial computed tomographic (CT) imaging in blunt trauma patients with significant mechanisms of injury, identifies BCVI that may go undetected. METHODS As per protocol, patients at risk for significant injuries undergo a noncontrast head CT scan followed by a multislice CT scan (40-slice or 64-slice) incorporating an intravenous contrast-enhanced pass from the circle of Willis through the pelvis (whole-body CT [WBCT] scan). The trauma registry was retrospectively reviewed, and all patients with BCVI from 2009 to 2012 were analyzed. Patients undergoing WBCT scan were then identified, and records were reviewed for BCVI indicators (skull base fracture, cervical spine injury, displaced facial fracture, mandible fracture, Glasgow Coma Scale score ⩽ 8, flexion mechanism, hard signs of neck vascular injury, or focal neurologic deficit). RESULTS Of 16,026 patients evaluated during the study period, 256 (1.6%) were diagnosed with BCVI. The population consisted of 185 patients with suspected BCVI after WBCT scan. One hundred twenty-nine patients (70%) had at least one indicator for BCVI screening, while 56 (30%) had no radiographic or clinical risk factors; 48 of the 56 patients underwent confirmatory CT angiography of the neck within 71 hours of initial WBCT scan, with 35 patients having 45 injuries. CONCLUSION More liberalized screening for BCVI during initial CT imaging in trauma patients clinically judged to have sufficient mechanism is warranted. Using current BCVI screening guidelines leads to missed BCVI and risk of stroke. LEVEL OF EVIDENCE Diagnostic study, level III.

Acute lung injury and the acute respiratory distress syndrome in the injured patient

Acute lung injury and acute respiratory distress syndrome are clinical entities of multi-factorial origin frequently seen in traumatically injured patients requiring intensive care. We performed an unsystematic search using PubMed and the Cochrane Database of Systematic Reviews up to January 2012. The purpose of this article is to review recent evidence for the pathophysiology and the management of acute lung injury/acute respiratory distress syndrome in the critically injured patient. Lung protective ventilation remains the most beneficial therapy. Future trials should compare intervention groups to controls receiving lung protective ventilation, and focus on relevant outcome measures such as duration of mechanical ventilation, length of intensive care unit stay, and mortality.

Can medical students achieve skills proficiency through simulation training

BACKGROUND The purpose of this study was to determine whether third-year medical students can become proficient in open technical skills through simulation laboratory training. METHODS A total of 204 students participated in a structured curriculum including bladder catheterization, breast examination, and knot-tying. Proficiency was documented using global rating scales and validated, objective, model-based metrics. RESULTS For catheterization and breast examination, all trainees showed proficiency, and self-rated comfort increased in more than 90%. For knot-tying, 83% completed the curriculum; 57% and 44% of trainees showed proficiency for 2- and 1-handed tasks, respectively. Objective performance scores improved significantly for 2- and 1-handed knot-tying (62.9-94.4 and 49.2-89.6, respectively; P < .001) and comfort rating also increased (28%-91% and 19%-80%, respectively; P < .001). CONCLUSIONS Objective scores and trainee self-ratings suggest that this structured curriculum using simulator training allows junior medical students to achieve proficiency in basic surgical skills.

Sleep deprivation after septic insult increases mortality independent of age

BACKGROUND Sleep deprivation is a common problem in the intensive care unit. Animal models have demonstrated that sleep deprivation alone is associated with increased mortality. We have previously shown that septic insult with sleep deprivation results in increased mortality in a murine model. The aging process is known to reduce the restorative phases of sleep. The purpose of this study was to evaluate the effect of age on mortality with sleep deprivation during recovery from septic insult. METHODS C57BL/6J male mice aged 2 months (young) or 9 months (old) underwent cecal ligation and puncture (CLP). Animals were randomized to receive sleep interruption (SI) for 48 hours or standard recovery (no SI). Sham animals underwent laparotomy and cecal manipulation without puncture. SI was achieved by securing animal housing to an orbital shaker set to repeatedly cycle at 30 rpm over 120 seconds (30 seconds on/90 seconds off). The primary outcome was survival at 5 days post-CLP. Kaplan-Meier survival analysis with log-rank test was used to explore differences in mortality. RESULTS SI resulted in an increase in time awake for both light and dark cycles (p < 0.001). Mortality after CLP with SI (n = 30) was 57% and mortality after CLP without SI (controls; n = 33) was 24%. SI was associated with a greater than 3-fold increase in mortality after CLP (RR = 3.29; 95% CI, 1.42-7.63). Young mice (n = 28) had a mortality of 31% with CLP alone increasing to 67% with SI (p = 0.03). Old mice (n = 35) had a mortality of 18% with CLP alone increasing to 50% with SI (p = 0.05). There was no difference in survival between young and old mice undergoing SI (p = 0.49). CONCLUSIONS Sleep deprivation after septic insult increases mortality in both young and old mice. However, sleep deprivation after septic insult does not have a more profound effect on mortality in either age group. These findings suggest that sleep deprivation experienced in the intensive care unit setting during recovery from critical illness may increase mortality. This effect appears independent of increased age. Further studies evaluating extremes of age are warranted.

Nontrauma open abdomens: A prospective observational study.

BACKGROUND Damage-control surgery with open abdomen (OA) is described for trauma, but little exists regarding use in the emergency general surgery. This study aimed to better define the following: demographics, indications for surgery and OA, fascial and surgical site complications, and in-hospital/long-term mortality. We hypothesize that older patients will have increased mortality, patients will have protracted stays, they will require specialized postdischarge care, and the indications for OA will be varied. METHODS A prospective observational study of emergency general surgery OA patients from June 2013 to June 2014 was performed. Demographics, clinical/operative variables, comorbidities, indications for procedure and OA, wound/fascial complications, and disposition were collected. Patients were stratified into age groups (⩽60, 61–79, and ≥80 years). Six-month and 1-year mortality was determined by query of the Social Security Death Index. RESULTS A total of 338 laparotomies were performed, of which 96 (28%) were managed with an OA. Median age was 61 years (interquartile range [IQR], 0–68 years), and 51% were male. The median Charlson Comorbidity Index was 2 (IQR, 1.5–5.1), and the median hospital stay was 25 days (IQR, 15–50 days). The most common indications for operation were perforated viscus/free air (20%), mesenteric ischemia (17%), peritonitis (16%), and gastrointestinal hemorrhage (12%). The most common indication for OA was damage control (37%). In the 63 patients with fascial closure, there were 9 (14%) wound infections and 6 (10%) fascial dehiscences. A total of 30% of the patients died in the hospital, and an additional six patients died 6 months after discharge. Patients in the oldest age stratum were more likely to die at 6 months than those in the lower strata. CONCLUSION Older patients were more likely to die by 6 months, the median hospital stay was 3 weeks, and there were multiple indications for OA management. With a 6-month mortality of 36% and 70% of survivors requiring postdischarge care, this population represents a critically ill population meriting additional study. LEVEL OF EVIDENCE Prognostic and epidemiologic study, level III.

Multicenter External Validation of the Geriatric Trauma Outcome Score: A Study by the Prognostic Assessment of Life and Limitations After Trauma in the Elderly [PALLIATE] Consortium

BACKGROUND A prognostic tool for geriatric mortality after injury called the Geriatric Trauma Outcome Score (GTOS), where GTOS = [age] + [ISS × 2.5] + [22 if transfused any PRBCs by 24 hours after admission], was previously developed based on 13 years of data from geriatric trauma patients admitted to Parkland Hospital. We sought to validate this model. METHODS Four Level I centers identified subjects who are 65 years or older for the period of the original study. The GTOS model was first specified using the formula [GTOS = age + (ISS × 2.5) + 22 (if given PRBC by 24 hours)] developed from the Parkland sample and then used as the sole predictor in a logistic mixed model estimating probability of mortality in the validation sample, accounting for site as a random effect. We estimated the misclassification (error) rate, Brier score, Tjur R2, and the area under the curve in evaluating the predictive performance of the GTOS model. RESULTS The original Parkland sample (n = 3,841) had a mean (SD) age of 76.6 (8.1) years, mean (SD) ISS of 12.4 (9.9), mortality of 10.8%, and 11.9% receiving PRBCs at 24 hours. The validation sample (n = 18,282) had a mean (SD) age of 77.0 (8.1) years, mean (SD) ISS of 12.3 (10.6), mortality of 11.0%, and 14.1% receiving PRBCs at 24 hours. Fitting the GTOS model to the validation sample revealed that the parameter estimates from the validation sample were similar to those of fitting it to the Parkland sample with highly overlapping 95% confidence limits. The misclassification (error) rate for the GTOS logistic model applied to the validation sample was 9.97%, similar to that of the Parkland sample (9.79%). Brier score, Tjur R2, and the area under the curve for the GTOS logistic model when applied to the validation sample were 0.07, 0.25, and 0.86, respectively, compared with 0.08, 0.20, and 0.82, respectively, for the Parkland sample. CONCLUSION With the use of the data available at 24 hours after injury, the GTOS accurately predicts in-hospital mortality for the injured elderly. LEVEL OF EVIDENCE Prognostic study, level III.

Alterations in the cardiac inflammatory response to burn trauma in mice lacking a functional Toll-like receptor 4 gene.

Our group and others have previously shown that Toll-like receptor 4 (TLR-4) inactivation prevents burn-induced myocardial contractile dysfunction; however, the molecular mechanisms that are involved in this cardioprotection are not well defined. This present study examines the involvement of TLR-4 in the cardiac inflammatory response to thermal insult. C3H/HeJ (TLR-4 mutant mice) and C3H/HeN wild-type (WT) mice were subjected to either a sham burn or 40% full-thickness burn injury and were fluid resuscitated with lactated Ringer using the Parkland formula. Mice (n = 7-9 per group) were killed at 2, 4, or 24 h postsham or burn, and heart tissue was harvested. Immunoblotting was performed to evaluate phosphorylated p38 mitogen-activated protein kinase (MAPK), nuclear p50, and cytoplasmic p50. Nuclear factor-&kgr;B was also characterized via electrophoretic mobility shift assay. Systemic and cardiac myocyte secretion of TNF-&agr;, IL-1&bgr;, IL-6, and IL-10 were measured by enzyme-linked immunosorbent assay. Burn injury in WT mice promoted myocardial inflammatory signaling that included increased expression of phosphorylated p38 MAPK, nuclear p50, and increased cardiac myocyte secretion of cytokines. Systemic cytokines were also increased in WT animals, although not to the extent of the myocardial cytokine expression. Toll-like receptor 4 inactivation resulted in an attenuation of several burn-induced responses, including phosphorylation of p38 MAPK, nuclear translocation of nuclear factor-&kgr;B, and cytokine secretion. These data suggest that burn injury initiates an inflammatory response via Toll/IL-1 signaling in the heart, which contributes to cardiac injury and contractile dysfunction.

Angiographic embolization for hemorrhage following pelvic fracture: Is it "time" for a paradigm shift?

Introduction Major pelvic disruption with hemorrhage has a high rate of lethality. Angiographic embolization remains the mainstay of treatment. Delays to angiography have been shown to worsen outcomes in part because time spent awaiting mobilization of resources needed to perform angiography allows ongoing hemorrhage. Alternative techniques like pelvic preperitoneal packing and aortic balloon occlusion now exist. We hypothesized that time to angiographic embolization at our Level 1 trauma center would be longer than 90 minutes. Methods A retrospective review was performed of patients with pelvic fracture who underwent pelvic angiography at our trauma center over a 10-year period. The trauma registry was queried for age, sex, injury severity score, hemodynamic instability (HI) on presentation, and transfusion requirements within 24 hours. Charts were reviewed for time to angiography, embolization, and mortality. Results A total of 4712 patients were admitted with pelvic fractures during the study period, 344 (7.3%) underwent pelvic angiography. Median injury severity score was 29. Median 24-hour transfusion requirements were five units of red blood cells and six units of fresh frozen plasma. One hundred fifty-one patients (43.9%) presented with HI and 104 (30%) received massive transfusion (MT). Median time to angiography was 286 minutes (interquartile range, 210–378). Times were significantly shorter when stratified for HI (HI, 264 vs stable 309 minutes; p = 0.003), and MT (MT, 230 vs non-MT, 317 minutes; p < 0.001), but still took nearly 4 hours. Overall mortality was 18%. Hemorrhage (35.5%) and sepsis/multiple-organ failure (43.5%) accounted for most deaths. Conclusion Pelvic fracture hemorrhage remains a management challenge. In this series, the median time to embolization was more than 5 hours. Nearly 80% of deaths could be attributed to early uncontrolled hemorrhage and linked to delays in hemostasis. Earlier intervention by Acute Care Surgeons with techniques like preperitoneal packing, aortic balloon occlusion, and use of hybrid operative suites may improve outcomes. Level of Evidence Therapeutic study, level V.