Dollars and Sense - The Financial Argument for Dedicated Post-Trauma Center Care

OBJECTIVE

The objective of the study was to demonstrate that creation of a Center for Trauma Survivorship (CTS) is not cost prohibitive but is a revenue generator for the institution.

BACKGROUND

A dedicated CTS has been demonstrated to increase adherence with follow-up visits and improve overall aftercare in severely injured patients discharged from the trauma center. A potential impediment to the creation of similar centers is its assumed prohibitive cost.

METHODS

This pre-and post-cohort study examines the financial impact of patients treated by the CTS. Patients in the PRE cohort were those treated in the year prior to CTS inception. Eligibility criteria are trauma patients admitted who are ≥18 years of age and have a NISS≥16 or ICU stay ≥2 days. Financial data was obtained from the hospital's billing and cost accounting systems for a one-year time period following discharge.

RESULTS

There were 176 patients in the PRE and 256 in the CTS cohort. The CTS cohort generated 1623 subsequent visits vs. 748 in the PRE cohort. CTS patients underwent more follow-up surgery in their first year of recovery as compared to the PRE cohort (98 vs 26 procedures). Each CTS patient was responsible for a $7,752 increase in net revenue with a positive contribution margin of $4,558 compared to those in the PRE group.

CONCLUSION

A dedicated CTS increases subsequent visits and necessary procedures and is a positive revenue source for the trauma center. The presumptive financial burden of a CTS is incorrect and the creation of dedicated centers will improve patients' outcomes and the institution's bottom line.

Straight Leg Raise Cannot Replace Computed Tomography in the Detection of Spinal Column Fractures

INTRODUCTION

An active straight leg raise (SLR) is a weight bearing test which assesses pain upon movement and a patient's ability to load their pelvis, lumbar, and thoracic spine. Since many stable patients undergo computed tomography (CT) scanning solely for spinal tenderness, our hypothesis is that performing active straight leg raising could effectively rule out lumbar and thoracic vertebral fractures.

METHODS

Blunt trauma patients ≥18 years of age with Glasgow Coma Scale 15 presenting in hemodynamically stable condition were screened. Patients remaining in the supine position were asked to perform SLR at 12, 18, and 24 inches above the bed. The patient's ability to raise the leg, baseline pain, and pain at each level were assessed. Patients also underwent standard CT scanning of the chest, abdomen and pelvis. The clinical examination results were then matched post hoc with the official radiology reports.

RESULTS

99 patients were screened, 65 males and 34 females. Spinal fractures were present in 15/99 patients (16%). Mechanisms of injury included motor vehicle collision 51%, pedestrian struck 25%, fall1 9%, and other 4%. The median pain score of patients with and without significant spinal fractures at 12, 18, 24 inches was 7.5, 7, 6 and 5, 5, 4, respectively. At 24 inches, active SLR had sensitivity of 0.47, a specificity of 0.59, a positive predictive value of 0.17, and an negative predictive value of 0.86.

CONCLUSIONS

Although SLR has been discussed as a useful adjunct to secondary survey and physical exam following blunt trauma, its positive and more importantly negative predictive value are insufficient to rule out spinal column fractures. Liberal indications for CT based upon mechanism and especially pain and tenderness are necessary to identify all thoraco-lumbar spine fractures.

The Geriatric Patient One Year After Trauma: Palliative Performance Scale Predicts Functional Outcomes

INTRODUCTION

Frailty in trauma has been found to predict poor outcomes after injury including additional in-hospital complications, mortality, and discharge to dependent care. These gross outcome measures are insufficient when discussing long-term recovery as they do not address what is important to patients including functional status and quality of life. The purpose of this study is to determine if the Palliative Performance Scale (PPS) predicts mortality and functional status one year after trauma in geriatric patients.

MATERIAL AND METHODS

Prospective observational study of trauma survivors, age ≥55 years. Patients were stratified by pre-injury PPS high (>70) or low (≤70). Outcomes were functional status at 1 year measured by Glasgow Outcome Scale Extended (GOSE), Euroqol-5D and SF-36. Adjusted relative risks (aRR) were obtained using modified Poisson regression.

RESULTS

Follow-up was achieved on 215/301 patients. Mortality was 30% in low PPS group vs 8% in the high PPS group (P<0.001). A greater percentage of patients in the high group had a good functional outcome at one year compared to patients in the low group (78% vs 30% p<0.001). The high PPS patients were more likely to have improvement of GOSE at 1 year from discharge compared to low group (66% vs 27% P<0.001). Low PPS independently predicted poor functional outcome (aRR, 2.64; 95% confidence interval, 1.79-3.89) and death at 1 year (aRR, 3.64; 95% confidence interval 1.68-7.92). An increased percentage of low PPS patients reported difficulty with mobility (91% vs 46% p<0.0001) and usual activities (82% vs 56% p=0.002). Both groups reported pain (65%) and anxiety/depression (47%).

CONCLUSION

Low pre-Injury PPS predicts mortality and poor functional outcomes one year after trauma. Low PPS patients were more likely to decline, rather than improve. Regardless of PPS, most patients have persistent pain, anxiety, and limitations in performing daily activities.

Measuring long-term outcomes after injury: current issues and future directions

Maximizing long-term outcomes for patients following injury is the next challenge in the delivery of patient-centered trauma care. The following review outlines three important components in trauma outcomes: (1) data gathering and monitoring, (2) the impact of traumatic brain injury, and (3) trajectories in recovery and identifies knowledge gaps and areas for needed future research.

INTERACTIONS BETWEEN BIOLOGICAL SEX AND THE X-LINKED VARIANT IRAK1 HAPLOTYPE IN MODULATING CLINICAL OUTCOME AND CELLULAR PHENOTYPES AFTER TRAUMA

ABSTRACT

Sex-related outcome differences in trauma remain controversial. The mechanisms causing sex-biased outcomes are likely to have hormonal and genetic components, in which X-linked genetic polymorphisms may play distinct roles because of X-linked inheritance, hemizygosity in males, and X chromosome mosaicism in females. The study aimed to elucidate the contribution of biological sex and the common X-linked IRAK1 haplotype to posttrauma clinical complications, inflammatory cytokine and chemokine production, and polymorphonuclear cell and monocyte activation. Postinjury clinical outcome was tested in 1507 trauma patients (1,110 males, 397 females) after stratification by sex or the variant IRAK1 haplotype. Males showed a three- to fivefold greater frequency of posttrauma sepsis, but similar mortality compared to females. Stratification by the variant IRAK1 haplotype revealed increased pneumonia and urinary tract infection in Wild type (WT) versus variant IRAK1 males, whereas increased respiratory failures in variant versus WT females. Cytokine/chemokine profiles were tested in whole blood from a subset of patients (n = 81) and healthy controls (n = 51), which indicated sex-related differences in ex vivo lipopolysaccharide responsiveness manifesting in a 1.5- to 2-fold increased production rate of tumor necrosis factor α, interleukin-1β (IL-1β), IL-10, Macrophage Inflammatory Protein-1 Alpha, and MIP1β in WT male compared to WT female trauma patients. Variant IRAK1 decreased IL-6, IL-8, and interferon gamma-induced protein 10 production in male trauma subjects compared to WT, whereas cytokine/chemokine responses were similar in variant IRAK1 and WT female trauma subjects. Trauma-induced and lipopolysaccharide-stimulated polymorphonuclear cell and monocyte activation determined by using a set of cluster of differentiation markers and flow cytometry were not influenced by sex or variant IRAK1. These findings suggest that variant IRAK1 is a potential contributor to sex-based outcome differences, but its immunomodulatory impacts are modulated by biological sex.

High resuscitative endovascular balloon occlusion of the aorta procedural volume is associated with improved outcomes: An analysis of the AORTA registry

BACKGROUND

The use of resuscitative endovascular balloon occlusion of the aorta (REBOA) is controversial. We hypothesize that REBOA outcomes are improved in centers with high REBOA utilization.

METHODS

We examined the Aortic Occlusion in Resuscitation for Trauma and Acute Care Surgery registry over a 5-year period (2014-2018). Resuscitative endovascular balloon occlusion of the aorta outcomes were analyzed by stratifying institutions into low-volume (<10), average-volume (11-30), and high-volume (>30) deployment centers. A multivariable model adjusting for volume group, mechanism of injury, signs of life, systolic blood pressure at initiation, operator level, device type, zone of placement, and hemodynamic response to aortic occlusion was created to analyze REBOA mortality and REBOA-related complications.

RESULTS

Four hundred ninety-five REBOA placements were included. High-volume centers accounted for 63%, while low accounted for 13%. High-volume institutions were more likely to place a REBOA in the emergency department (81% vs. 63% low volume, p = 0.003), had a lower mean systolic blood pressure at insertion (53 ± 38 vs. 64 ± 40, p = 0.001), and more Zone I deployments (64% vs. 55%, p = 0.002). Median time from admission to REBOA placement was significantly less in patients treated at high-volume centers (15 [7-30] minutes vs. 35 [20-65] minutes, p = 0.001). Resuscitative endovascular balloon occlusion of the aorta mortality was significantly higher at low-volume centers (67% vs. 57%; adjusted odds ratio, 1.29; adj p = 0.040), while average- and high-volume centers were similar. Resuscitative endovascular balloon occlusion of the aorta complications were less frequent at high-/average-volume centers, but did not reach statistical significance (adj p = 0.784).

CONCLUSION

Resuscitative endovascular balloon occlusion of the aorta survival is increased at high versus low utilization centers. Increased experience with REBOA may be associated with earlier deployment and subsequently improved patient outcomes.

LEVEL OF EVIDENCE

Therapeutic/Care Management, level IV.

Surgical Skills Olympiad: A 4-Year Experience in a General Surgery Residency Program

Background  The acquisition of operative skills is the critical defining component of general surgery training. Performing simulated tasks has been shown to increase a resident's technical skills. As such, we devised the Surgical Skills Olympiad, an annual simulation-based skills competition. We examined our 4-year experience with the Olympiad at a large academic general surgery residency program.

Objective  This study aimed to use competition to motivate trainees to increase the time they spent practicing basic surgical skills, resulting in improved performance over time.

Methods  Teams were formed from members of each postgraduate year (PGY) class. Competition tasks were level specific: knot tying for PGY-1, basic laparoscopy for PGY-2, handsewn bowel anastomosis for PGY-3, vascular anastomosis for PGY-4, and advanced laparoscopy for PGY-5. Task scores over a 4-year period (2014–2017) were analyzed and a survey of participating teaching faculty was conducted.

Results  Ten faculty members responded to the survey, for a response rate of 63%. A total of 50% respondents felt that the caliber of surgical skills increased since the Olympiad was implemented. Ninety percent agreed that the Olympiad was beneficial for residents to assess their skills against their peers. Over 4 years, there was an improvement in scores for suturing task, advanced laparoscopy, and bowel anastomosis ( p  < 0.05 for all three).

Conclusion  A residency-wide surgical skills competition can improve resident performance in technical tasks and promote faculty engagement in resident skills training.

Utilizing triage rates to improve ICU admission guidelines of elderly rib fracture patients

BACKGROUND

Elderly rib fracture patients are generally admitted to an ICU which may result in overutilization of scarce resources. We hypothesized that this practice results in significant overtriage.

METHODS

Retrospective study of patients over age 70 with acute rib fracture(s) as sole indication for ICU admission. Primary outcomes were adverse events (intubation, pneumonia, death), which we classified as meriting ICU admission. We utilized Cribari matrices to calculate triage rates.

RESULTS

101 patients met study criteria. 12% had adverse events occurring on average at day 5. Our undertriage rate was 6% and overtriage rate 87%. The 72 overtriaged patients utilized 295 total ICU days. Evaluating guideline modification, ≥3 fractures appears optimal. Changing to this would have liberated 50 ICU days with 3% undertriage.

CONCLUSION

Elderly patients with small numbers of rib fractures are overtriaged to ICUs. Modifying guidelines to ≥3 rib fractures will improve resource utilization and save ICU beds.

Pulmonary complications in trauma patients with obstructive sleep apnea undergoing pelvic or lower limb operation

Background

Obstructive sleep apnea (OSA) is increasingly prevalent in the range of 2% to 24% in the US population. OSA is a well-described predictor of pulmonary complications after elective operation. Yet, data are lacking on its effect after operations for trauma. We hypothesized that OSA is an independent predictor of pulmonary complications in patients undergoing operations for traumatic pelvic/lower limb injuries (PLLI).

Methods

Nationwide Inpatient Sample (2009–2013) was queried for International Classification of Diseases, Ninth Revision, Clinical Modification codes for PLLI requiring operation. Elective admissions and those with concurrent traumatic brain injury with moderate to prolonged loss of consciousness were excluded. Outcome measures were pulmonary complications including ventilatory support, ventilator-associated pneumonia, pulmonary embolism (PE), acute respiratory distress syndrome (ARDS), and respiratory failure. Multivariable logistic regression analysis was used, adjusting for OSA, age, sex, race/ethnicity, and specific comorbidities (obesity, chronic lung disease, and pulmonary circulatory disease). P<0.01 was considered statistically significant.

Results

Among the 337 333 patients undergoing PLLI operation 3.0% had diagnosed OSA. Patients with OSA had more comorbidities and were more frequently discharged to facilities. Median length of stay was longer in the OSA group (5 vs 4 days, p<0.001). Pulmonary complications were more frequent in those with OSA. Multivariable logistic regression showed that OSA was an independent predictor of ventilatory support (adjusted odds ratio (aOR), 1.37; 95% CI,1.24 to 1.51), PE (aOR 1.40; 95% CI, 1.15 to 1.70), ARDS (aOR 1.36; 95% CI,1.23 to 1.52), and respiratory failure (aOR 1.90; 95% CI, 1.74 to 2.06).

Conclusion

OSA is an independent and underappreciated predictor of pulmonary complications in those undergoing emergency surgery for PLLI. More aggressive screening and identification of OSA in trauma patients undergoing operation are necessary to provide closer perioperative monitoring and interventions to reduce pulmonary complications and improve outcomes.

Level of evidence

Prognostic Level IV.

Treatment of Acute Cholecystitis at Safety-Net Hospitals: Analysis of the National Inpatient Sample

Evidence supports index cholecystectomy as the quality of care for patients admitted with acute cholecystitis. We sought to examine the role of hospital safety-net status on whether patients received appropriate index procedures for cholecystitis. The National Inpatient Sample was queried for patients with acute cholecystitis. Proportion of Medicaid and uninsured discharges were used to define safety-net hospitals (SNHs). Multivariate logistic regression was used to calculate associations between the frequency of index cholecystectomy and prolonged length of stay (LOS), and the effect of SNH designation. SNHs and non-SNHs had similar rates of index cholecystectomy in all geographic regions, except in the northeast, where the likelihood of having an index cholecystectomy was lower at SNHs. Patients at SNHs had longer LOS for acute cholecystitis, regardless of index or delayed cholecystectomy. When controlling for insurance status, patients at SNHs had longer LOS than those at non-SNHs. There was also increased LOS in SNHs in the Midwest, in urban hospitals, and in large hospitals. Our data showed no difference in the frequency of index cholecystectomy overall between SNHs and non-SNHs, except in the northeast. The variability and increased LOS at SNHs highlight potential opportunities to improve quality and decrease cost of care at our most vulnerable hospitals.

Civilian Craniocerebral Gunshot Wounds: An Update in Predicting Outcomes

Given the high mortality in patients sustaining intracranial injury secondary to gunshot wounds (GSWs), predictors to identify patients at increased risk of death are needed to assist clinicians early in determining optimal treatment. There have been few recent studies involving penetrating craniocerebral injuries, and most studies have been restricted to small numbers of patients, which do not allow for adequate prediction of mortality. A retrospective chart review of 298 patients who sustained GSWs to the head between 1992 and 2003 was conducted at a level 1 trauma center. Demographics, bullet trajectory, admitting Glasgow Coma Scale (GCS), head Abbreviated Injury Score (AIS), as well as admission blood pressure and respiratory rate were evaluated. Univariate testing followed by multivariate logistic regression was performed to identify independent predictors of death. In-hospital mortality for patients with intracranial injury secondary to GSW was 51 per cent. A GCS <5 on admission and a high Injury Severity Score (ISS >25) was associated with mortality as compared with survivors ( P < 0.05). Of those patients presenting with a GCS of 3, there were seven survivors to discharge. Logistic regression identified the following variables as predictors of death: respiratory arrest on admission, hypotension on admission, transhemispheric and transventricular GSW. Identification of those patients at the highest risk of death secondary to a craniocerebral GSW allows clinicians to better predict outcome and prognosis. This is not only important in determining treatment algorithms for physicians but also for appropriate counseling of family members to educate them with regard to patients’ outcomes.

Tube thoracostomy during the COVID-19 pandemic: guidance and recommendations from the AAST Acute Care Surgery and Critical Care Committees

This document provides guidance for trauma and acute care surgeons surrounding the placement, management and removal of chest tubes during the COVID-19 pandemic.

Natural Language Processing Accurately Measures Adherence to Best Practice Guidelines for Palliative Care in Trauma

CONTEXT

The Trauma Quality Improvement Program Best Practice Guidelines recommend palliative care (PC) concurrent with restorative treatment for patients with life-threatening injuries. Measuring PC delivery is challenging: administrative data are nonspecific, and manual review is time intensive.

OBJECTIVES

To identify PC delivery to patients with life-threatening trauma and compare the performance of natural language processing (NLP), a form of computer-assisted data abstraction, to administrative coding and gold standard manual review.

METHODS

Patients 18 years and older admitted with life-threatening trauma were identified from two Level I trauma centers (July 2016-June 2017). Four PC process measures were examined during the trauma admission: code status clarification, goals-of-care discussion, PC consult, and hospice assessment. The performance of NLP and administrative coding were compared with manual review. Multivariable regression was used to determine patient and admission factors associated with PC delivery.

RESULTS

There were 76,791 notes associated with 2093 admissions. NLP identified PC delivery in 33% of admissions compared with 8% using administrative coding. Using NLP, code status clarification was most commonly documented (27%), followed by goals-of-care discussion (18%), PC consult (4%), and hospice assessment (4%). Compared with manual review, NLP performed more than 50 times faster and had a sensitivity of 93%, a specificity of 96%, and an accuracy of 95%. Administrative coding had a sensitivity of 21%, a specificity of 92%, and an accuracy of 68%. Factors associated with PC delivery included older age, increased comorbidities, and longer intensive care unit stay.

CONCLUSION

NLP performs with similar accuracy with manual review but with improved efficiency. NLP has the potential to accurately identify PC delivery and benchmark performance of best practice guidelines.

Preinjury Palliative Performance Scale predicts functional outcomes at 6 months in older trauma patients

BACKGROUND

Older trauma patients have increased risk of adverse in-hospital outcomes. We previously demonstrated that low preinjury Palliative Performance Scale (PPS) independently predicted poor discharge outcomes. We hypothesized that low PPS would predict long-term outcomes in older trauma patients.

METHODS

Prospective observational study of trauma patients aged ≥55 years admitted between July 2016 and April 2018. Preinjury PPS was assessed at admission; low PPS was defined as 70 or less. Primary outcomes were mortality and functional outcomes, measured by Extended Glasgow Outcome Scale (GOSE), at discharge and 6 months. Poor functional outcomes were defined as GOSE score of 4 or less. Secondary outcomes were patient-reported outcomes at 6 months: EuroQol-5D and 36-Item Short Form Survey. Adjusted relative risks (aRRs) were obtained for each primary outcome using multivariable modified Poisson regression, adjusting for PPS, age, race/ethnicity, sex, and injury severity.

RESULTS

In-hospital data were available for 516 patients; mean age was 70 years and median Injury Severity Score was 13. Thirty percent had low PPS. Six percent (n = 32) died in the hospital, and half of the survivors (n = 248) had severe disability at discharge. Low PPS predicted hospital mortality (aRR, 2.6; 95% confidence interval [CI], 1.2-5.3) and poor outcomes at discharge (aRR, 2.0; 95% CI, 1.7-2.3). Six-month data were available for 176 (87%) of 203 patients who were due for follow-up. Functional outcomes improved in 64% at 6 months. However, 63% had moderate to severe pain, and 42% moderate to severe anxiety/depression. Mean GOSE improved less over time in low PPS patients (7% vs. 24%; p < 0.01). Low PPS predicted poor functional outcomes at 6 months (aRR, 3.1; 95% CI, 1.8-5.3) while age and Injury Severity Score did not.

CONCLUSION

Preinjury PPS predicts mortality and poor outcomes at discharge and 6 months. Despite improvement in function, persistent pain and anxiety/depression were common. Low PPS patients fail to improve over time compared to high PPS patients. Preinjury PPS can be used on admission for prognostication of short- and long-term outcomes and is a potential trigger for palliative care in older trauma patients.

LEVEL OF EVIDENCE

Prognostic study, Therapeutic level IV.

Treatment of Acute Cholecystitis at Safety-Net Hospitals: Analysis of the National Inpatient Sample

Evidence supports index cholecystectomy as the quality of care for patients admitted with acute cholecystitis. We sought to examine the role of hospital safety-net status on whether patients received appropriate index procedures for cholecystitis. The National Inpatient Sample was queried for patients with acute cholecystitis. Proportion of Medicaid and uninsured discharges were used to define safety-net hospitals (SNHs). Multivariate logistic regression was used to calculate associations between the frequency of index cholecystectomy and prolonged length of stay (LOS), and the effect of SNH designation. SNHs and non-SNHs had similar rates of index cholecystectomy in all geographic regions, except in the northeast, where the likelihood of having an index cholecystectomy was lower at SNHs. Patients at SNHs had longer LOS for acute cholecystitis, regardless of index or delayed cholecystectomy. When controlling for insurance status, patients at SNHs had longer LOS than those at non-SNHs. There was also increased LOS in SNHs in the Midwest, in urban hospitals, and in large hospitals. Our data showed no difference in the frequency of index cholecystectomy overall between SNHs and non-SNHs, except in the northeast. The variability and increased LOS at SNHs highlight potential opportunities to improve quality and decrease cost of care at our most vulnerable hospitals.

Directional X Chromosome Skewing of White Blood Cells from Subjects with Heterozygous Mosaicism for the Variant IRAK1 Haplotype

Random X chromosome (ChrX) inactivation and consequent cellular mosaicism for the active ChrXs in white blood cells (WBCs) is unique to females and may contribute to sex-biased modulation of the innate immune response. Polymorphic differences between the two parental ChrXs may result in ChrX skewing of circulating WBCs (ChrX inactivation-ratio (XCI) > 3) driven by differences in stem cell selection and activity in the bone marrow or WBC trafficking at the periphery. Independent of the mechanism, ChrX skewing may result in genotype-phenotype discrepancies. This study aimed to develop an allele-specific assay and test its applicability in clinical samples to determine the "direction" of ChrX skewing in the variant IRAK1 haplotype, a common X-linked polymorphism with major clinical impacts. Because alternative splice variants of IRAK1 are also produced in the region surrounding the critical single-nucleotide polymorphism (SNP, rs1059703), we also tested the abundance of alternative splice variant IRAK1 transcripts. The expression of splice variants IRAK1-B and IRAK1-C was about 30 and 50% of the full-length (IRAK1-A) in WBCs from healthy subjects (n = 53). IRAK1-A, B, and C showed about 30% lower expression level in males (n = 25) than females (n = 28). By contrast, the expression levels of IRAK1-A, B, and C were not affected by the variant IRAK1 haplotype in either sex. Allele-specific primers generated WT and variant-IRAK1 amplicons with high selectivity, and on average produced about half the expression levels of each transcript in heterozygous IRAK1-mosaic females. Because injury was shown to induce de novo ChrX skewing of WBCs, we tested the directional XCI ratio changes in WBC in a sample of trauma patients heterozygous for the variant IRAK1 haplotype (n = 18). Using the allele-specific assay in combination with the DNA methylation status at the polymorphic HUMARA locus, we found that at admission, about 60% the patients presented XCI ratios skewed toward WBCs with active ChrXs carrying the variant-IRAK1 similar to healthy controls. De novo, trauma-induced XCI ratio changes showed increased extravasation of the more abundant mosaic WBC subset without reversal in the direction of ChrX skewing during the injury course.

Sarcopenia is Predictive of Functional Outcomes in Older Trauma Patients

Introduction: Older patients are more vulnerable to poor outcomes after trauma than younger patients. Sarcopenia, loss of skeletal mass, is prevalent in trauma patients admitted to the intensive care unit (ICU), and it has been shown to correlate with adverse outcomes, such as mortality and ICU days. Yet, little is known whether it predicts other outcomes. We hypothesized that sarcopenia independently predicts poor functional outcomes in older trauma patients admitted to the ICU.

Methods: We performed a retrospective review of patients aged >55 admitted to a surgical ICU in a Level I trauma center for two years. Sarcopenic status was determined by measuring total skeletal muscle cross-sectional area at the L3 level on admission computed tomography (CT), normalized for height with sex-specific cutoffs. Primary outcome measures were in-hospital mortality, functional outcomes measured by the Glasgow Outcome Scale (GOS) at discharge, and discharge disposition. Multivariable logistic regression was used to determine predictors of primary outcomes.

Results: Out of 230 patients, 32% were sarcopenic. The overall mortality was 20%, and 30% were discharged with poor functional outcomes. A higher proportion of sarcopenic patients among survivors had poor functional outcomes at discharge (55% vs. 30%, p=0.002). Sarcopenia was not predictive of in-hospital mortality but was an independent predictor of poor functional outcomes at discharge (OR 2.6; 95% confidence interval [CI] 1.3-5.5), adjusting for age, Glasgow Coma Scale (GCS) on admission, diagnosis of traumatic brain injury (TBI), Injury Severity Score (ISS), and the number of life-limiting illnesses.

Conclusions: Sarcopenia is prevalent in geriatric trauma ICU patients and is an independent predictor of poor functional outcomes. Assessing for sarcopenia has an important potential as a prognostic tool in older trauma patients.

Bleeding and Thromboembolism After Traumatic Brain Injury in the Elderly: A Real Conundrum

BACKGROUND

Elderly patients presenting with a traumatic brain injury (TBI) often have comorbidities that increase risk of thromboembolic (TE) disease and recurrent TBI. A significant number are on anticoagulant therapy at the time of injury and studies suggest that continuing anticoagulation can prevent TE events. Understanding bleeding, recurrent TBI, and TE risk after TBI can help to guide therapy. Our objectives were to 1) evaluate the incidence of bleeding, recurrent TBI, and TE events after an initial TBI in older adults and 2) identify which factors contribute to this risk.

METHODS

Retrospective analysis of Medicare claims between May 30, 2006 and December 31, 2009 for patients hospitalized with TBI was performed. We defined TBI for the index admission, and hemorrhage (gastrointestinal bleeding or hemorrhagic stroke), recurrent TBI, and TE events (stroke, myocardial infarction, deep venous thrombosis, or pulmonary embolism) over the following year using ICD-9 codes. Unadjusted incidence rates and 95% confidence intervals (CIs) were calculated. Risk factors of these events were identified using logistic regression.

RESULTS

Among beneficiaries hospitalized with TBI, incidence of TE events (58.6 events/1000 person-years; 95% CI 56.2, 60.8) was significantly higher than bleeding (23.6 events/1000 person-years; 95% CI 22.2, 25.1) and recurrent TBI events (26.0 events/1000 person-years; 95% CI 24.5, 27.6). Several common factors predisposed to bleeding, recurrent TBI, and TE outcomes.

CONCLUSIONS

Among Medicare patients hospitalized with TBI, the incidence of TE was significantly higher than that of bleeding or recurrent TBI. Specific risk factors of bleeding and TE events were identified which may guide care of older adults after TBI.

First rib fracture: A harbinger of severe trauma?

BACKGROUND

Prior to routine CT scanning, first rib fractures (FRFs) were considered a harbinger of great vessel injuries. We hypothesized FRFs identified on screening CXR have significant associated injuries, while those identified on CT alone do not.

METHODS

We reviewed adult blunt thoracic trauma patients 2014-2015 to identify all FRFs and then tabulated demographics, injury characteristics, and outcomes.

RESULTS

Of 429 patients with chest trauma, 56 had a FRF. CXR diagnosed 20% and CT 80%. Those diagnosed on CXR were older (61 vs 48 p = 0.03), had more severe chest trauma (45% vs 13% chest AIS>3, p = 0.029), longer ICU stays (10 vs 4 days, p = 0.046), and risk for intubation (73% vs 27%, p = 0.011). There was only one major vascular injury in each group. Most FRF patients had associated injuries, including 82% with pelvic fractures.

CONCLUSIONS

Widespread use of CT scanning has resulted in a 5-fold increase in FRF diagnoses. While vascular injuries are not common, especially when identified on initial CXR, FRFs correlate with morbidity and associated injuries.

Inherent X-Linked Genetic Variability and Cellular Mosaicism Unique to Females Contribute to Sex-Related Differences in the Innate Immune Response

Females have a longer lifespan and better general health than males. Considerable number of studies also demonstrated that, after trauma and sepsis, females present better outcomes as compared to males indicating sex-related differences in the innate immune response. The current notion is that differences in the immuno-modulatory effects of sex hormones are the underlying causative mechanism. However, the field remains controversial and the exclusive role of sex hormones has been challenged. Here, we propose that polymorphic X-linked immune competent genes, which are abundant in the population are important players in sex-based immuno-modulation and play a key role in causing sex-related outcome differences following trauma or sepsis. We describe the differences in X chromosome (ChrX) regulation between males and females and its consequences in the context of common X-linked polymorphisms at the individual as well as population level. We also discuss the potential pathophysiological and immune-modulatory aspects of ChrX cellular mosaicism, which is unique to females and how this may contribute to sex-biased immune-modulation. The potential confounding effects of ChrX skewing of cell progenitors at the bone marrow is also presented together with aspects of acute trauma-induced de novo ChrX skewing at the periphery. In support of the hypothesis, novel observations indicating ChrX skewing in a female trauma cohort as well as case studies depicting the temporal relationship between trauma-induced cellular skewing and the clinical course are also described. Finally, we list and discuss a selected set of polymorphic X-linked genes, which are frequent in the population and have key regulatory or metabolic functions in the innate immune response and, therefore, are primary candidates for mediating sex-biased immune responses. We conclude that sex-related differences in a variety of disease processes including the innate inflammatory response to injury and infection may be related to the abundance of X-linked polymorphic immune-competent genes, differences in ChrX regulation, and inheritance patterns between the sexes and the presence of X-linked cellular mosaicism, which is unique to females.

An Innovative Way to Separate Gastrointestinal and Abdominal Wall Reconstruction after Complex Abdominal Trauma

Despite advances in trauma care, a subset of patients surviving damage control cannot achieve fascial closure and require split-thickness skin grafting (STSG) of their open abdomen. Controversy exists as to whether reconstruction of the gastrointestine (GI) should be staged or performed at the time of abdominal wall reconstruction (AWR). Many surgeons do not believe that operations through the STSG can be completed safely or without loss of graft. This series reviews the outcomes of operations for GI reconstruction performed through the elevated healed STSG. Concurrent series on all patients undergoing abdominal operation through the STSG. The technique involves elevating the STSG, lysing adhesions only as needed, avoid detaching underlying omentum or viscera to avoid devascularization, and then reattaching the elevated STSG to the abdominal wall with simple sutures. From 1995 to 2017, 27 patients underwent 40 distinct procedures during 36 separate abdominal reoperations (89% GI) through the elevated STSG approach at three Level I trauma centers at a mean interval of 11 months from application of the STSG. One STSG was lost (patient closed with skin flaps), one patient had 30 per cent loss of the STSG (regrafted), and one patient had 10 per cent loss of the STSG (allowed to granulate). One patient required a small bowel resection for intraoperative enterotomy during a difficult operative dissection. There were no GI complications, intraabdominal infections, or deaths, and all patients were deemed fit to undergo AWR after three months. Major intraabdominal reoperations can be readily and safely accomplished through the elevated STSG approach with a <4 per cent need for regrafting. This staged approach significantly simplifies and increases the safety of a second stage AWR.

An Innovative Way to Separate Gastrointestinal and Abdominal Wall Reconstruction after Complex Abdominal Trauma

Despite advances in trauma care, a subset of patients surviving damage control cannot achieve fascial closure and require split-thickness skin grafting (STSG) of their open abdomen. Controversy exists as to whether reconstruction of the gastrointestine (GI) should be staged or performed at the time of abdominal wall reconstruction (AWR). Many surgeons do not believe that operations through the STSG can be completed safely or without loss of graft. This series reviews the outcomes of operations for GI reconstruction performed through the elevated healed STSG. Concurrent series on all patients undergoing abdominal operation through the STSG. The technique involves elevating the STSG, lysing adhesions only as needed, avoid detaching underlying omentum or viscera to avoid devascularization, and then reattaching the elevated STSG to the abdominal wall with simple sutures. From 1995 to 2017, 27 patients underwent 40 distinct procedures during 36 separate abdominal reoperations (89% GI) through the elevated STSG approach at three Level I trauma centers at a mean interval of 11 months from application of the STSG. One STSG was lost (patient closed with skin flaps), one patient had 30 per cent loss of the STSG (regrafted), and one patient had 10 per cent loss of the STSG (allowed to granulate). One patient required a small bowel resection for intraoperative enterotomy during a difficult operative dissection. There were no GI complications, intraabdominal infections, or deaths, and all patients were deemed fit to undergo AWR after three months. Major intraabdominal reoperations can be readily and safely accomplished through the elevated STSG approach with a <4 per cent need for regrafting. This staged approach significantly simplifies and increases the safety of a second stage AWR.

Severe dysphagia requiring gastrostomy following cervical spine fracture fixation

BACKGROUND

The incidence of severe dysphagia requiring gastrostomy tube (GT) placement following operative fixation of traumatic cervical spine fractures is unknown. Risk factors for severe dysphagia are not well identified and GT placement is often delayed due to the belief that it will resolve quickly. We hypothesized that patient and clinical factors could be used to predict severe dysphagia requiring GT placement in this population.

METHODS

A retrospective multicenter review of all adult patients requiring operative fixation of cervical spine fractures was performed. Data on demographics, injury severity score, presence of spinal cord injury, operative approach, presence of severe traumatic brain injury, and the need and timing of tracheostomy and GT were collected. The timing, number and results of formal speech, and language pathology examinations were also recorded.

RESULTS

243 patients underwent cervical spine fixation for traumatic fractures, of which 72 (30%) required GT placement. Patients requiring gastrostomy were significantly older, 54 versus 45 years (p=0.002), and had higher injury severity scores at 24 versus 18 (p<0.0001). Tracheostomy was strongly associated with severe dysphagia; GT was required in 83% of patients who underwent tracheostomy versus 5% of those who did not require tracheostomy. 50% of patients underwent tracheostomy and GT on the same day after injury, with the remaining patients having an average of 9 days delay between procedures. The need for gastrostomy placement was also higher in patients undergoing combined operative approach versus anterior or posterior approach alone (p=0.02). There were no GT-related complications.

CONCLUSIONS

Severe dysphagia requiring GT placement occurs commonly (30%) in patients who undergo operative fixation of cervical spine fractures. Gastrostomy placement was delayed in 50%. Tracheostomy was strongly associated with the need for GT placement. Earlier GT placement, especially in patients requiring tracheostomy, would improve patient care and disposition.

Mesenchymal stem cells reverse trauma and hemorrhagic shock-induced bone marrow dysfunction

BACKGROUND

Lung contusion (LC) followed by hemorrhagic shock (HS) causes persistent bone marrow (BM) dysfunction lasting up to 7 d after injury. Mesenchymal stem cells (MSCs) are multipotent cells that can hasten healing and exert protective immunomodulatory effects. We hypothesize that MSCs can attenuate BM dysfunction after combined LCHS.

MATERIALS AND METHODS

Male Sprague-Dawley rats (n = 5-6 per group) underwent LC plus 45 min of HS (mean arterial pressure of 30-35). Allogeneic MSCs (5 × 10(6) cells) were injected intravenously after resuscitation. At 7 d, BM was analyzed for cellularity and growth of hematopoietic progenitor cell (HPC) colonies (colony-forming unit-erythroid; burst-forming unit-erythroid; and colony-forming unit-granulocyte, erythrocyte, monocyte, megakaryocyte). Flow cytometry measured %HPCs in peripheral blood; plasma granulocyte colony-stimulating factor (G-CSF) levels were measured via enzyme-linked immunosorbent assay. Data were analyzed by one-way analysis of variance followed by the Tukey multiple comparison test.

RESULTS

As previously shown, at 7 d, LCHS resulted in 22%, 30%, and 24% decreases in colony-forming unit-granulocyte, erythrocyte, monocyte, megakaryocyte, burst-forming unit-erythroid, and colony-forming unit-erythroid colony growth, respectively, versus naive. Treatment with MSCs returned all BM parameters to naive levels. There was no difference in %HPCs in peripheral blood between groups; however, G-CSF remained increased up to 7 d after LCHS. MSCs returned G-CSF to naive levels. Plasma from animals receiving MSCs was not suppressive to the BM.

CONCLUSIONS

One week after injury, the persistent BM dysfunction observed in animals undergoing LCHS is reversed by treatment with MSCs with an associated return of plasma G-CSF levels to normal. Plasma from animals undergoing LCHS plus MSCs was not suppressive to BM cells in vitro. Treatment with MSCs after injury and shock reverses BM suppression and returns plasma G-CSF levels to normal.

Early propranolol administration to severely injured patients can improve bone marrow dysfunction

BACKGROUND

Bone marrow (BM) dysfunction is common in severely injured trauma patients, resulting from elevated catecholamines and plasma granulocyte colony-stimulating factor (G-CSF) as well as prolonged mobilization of hematopoietic progenitor cells (HPCs). We have previously shown that propranolol (β-blocker [BB]) reduces HPC mobilization in a rodent model of injury and hemorrhagic shock. We hypothesize that BB would prevent BM dysfunction in humans following severe injury.

METHODS

Forty-five severely injured trauma patients were studied in a prospective, randomized pilot trial. Twenty-five patients received BB, and 20 served as untreated controls. The dose of propranolol was adjusted to decrease the heart rate by 10% to 20% from baseline. Blood was analyzed for the presence of HPC (blast-forming unit erythroid cells [BFU-E] and colony-forming unit erythroid cells) and G-CSF. Demographic data, Injury Severity Score (ISS), hemoglobin, reticulocyte number, and outcome data were obtained.

RESULTS

The mean age of the study population was 33 years; 87% were male, with a mean ISS of 29. There is a significant increase in BFU-E in peripheral blood immediately following traumatic injury, and this mobilization persists for 30 days. The use of BB significantly decreases BFU-E and colony-forming unit erythroid cells at all time points. G-CSF is significantly elevated in both groups on admission; the use of BB decreases G-CSF levels by 51% as compared with 37% for controls. The average hemoglobin is nearly 1 g higher on the day of discharge with propranolol treatment (BB, 9.9 ± 0.4 g/dL vs. no BB, 9.1 ± 0.6 g/dL).

CONCLUSION

Following severe trauma, early treatment with propranolol following resuscitation is safe. The use of propranolol blunts early tachycardia, reduces HPC mobilization, and results in a faster return to baseline of the G-CSF peak seen after injury. There is also a trend toward faster recovery and resolution of anemia. Propranolol may be the first therapeutic agent to show improved BM function after severe injury.

LEVEL OF EVIDENCE

Therapeutic study, level III.

Bacteremia and ventilator-associated pneumonia: a marker for contemporaneous extra-pulmonic infection

BACKGROUND

Ventilator-associated pneumonia (VAP) is a well-known complication of mechanical ventilation in severely injured patients. A subset of patients with VAP develop an associated bacteremia (B-VAP), but the risk factors, microbiology, morbidity, and mortality in this group are not well described. The goal of this study was to examine the incidence, predictors, and outcome of B-VAP in adult trauma patients.

METHODS

We conducted a retrospective review of trauma patients who developed VAP or B-VAP from January 2007 to December 2009 at a single, university-affiliated medical center. Ventilator-associated pneumonia was defined as a clinician-documented instance of VAP together with confirmed positive respiratory cultures (bronchoalveolar lavage [BAL] fluid specimen with ≥10(4) colony forming units (CFU)/mL or tracheal aspirate with moderate-to-many organisms and polymorphonuclear neutrophils [PMN]). Bacteremia associated with VAP (B-VAP) was defined as the blood culture of an organism that matched the pulmonary pathogen in a case of VAP. We reviewed the demographic data, injury severity, transfusion data, and microbiology of patients who developed VAP and B-VAP. Outcome data included the number of days of care in the intensive care unit (ICU) and hospital length of stay, number of days of mechanical ventilation, and survival. A Student t-test, χ(2) test, or logistic regression was used as appropriate for data analysis.

RESULTS

During the 36-mo period of the study, 4,018 adult patients were admitted to the hospital. Ventilator-associated pneumonia was diagnosed in 206 (5%) of these patients, and 26 of these latter patients (13%) had an associated bacteremia. The mean time from admission to the development of VAP was 5 d (95% CI 4.6-5.8). Patients who had B-VAP received significantly more units of red blood cell concentrates (PRBC) than those who did not have B-VAP (23 units vs. 9 units of PRBC, respectively, p<0.05). Patients with B-VAP also had higher rates of simultaneous non-pulmonary infections than those with VAP alone (69% vs. 38%, respectively), a greater number of days of mechanical ventilator support (24 d vs. 14 d, respectively, p<0.05), a greater number of days in the ICU (26 d vs. 17 d, respectively, p<0.05), and a greater hospital length of stay (50 d vs. 30 d, respectively, p<0.05). Patients with B-VAP showed a trend toward lower survival than those without B-VAP, but B-VAP was not an independent predictor of mortality.

CONCLUSIONS

Trauma patients with B-VAP have a similar mortality but greater morbidity than those with VAP alone. The number of PRBC received is the most significant risk factor for developing B-VAP. More than two-thirds of patients with B-VAP have contemporaneous extra-pulmonic infections. Trauma patients with B-VAP may benefit from increased surveillance for additional concomitant infections and from more aggressive empiric antimicrobial coverage.

Obesity Does Not Increase Morbidity and Mortality after Laparotomy for Trauma

Obesity has been suggested to be a risk factor for increase morbidity and mortality after trauma and surgery. Trauma laparotomy provides an opportunity to assess the effect of body mass index (BMI) on patients subjected to both trauma and surgery. We hypothesized that obesity would have a deleterious effect on outcomes. A retrospective review was conducted of all patients 18 years of age or older undergoing laparotomy for trauma between July 2001 and June 2011. Patients were stratified according to BMI into the following four groups: underweight (16 to 22 kg/m2), normal (23 to 27 kg/m2), overweight (28 to 34 kg/m2), and obese (35 kg/m2 or higher). Data on the patient's hospital course included length of stay, mortality, respiratory failure, infectious complications, wound dehiscence, and organ failure. A total of 1,297 patients underwent laparotomy. Seven per cent of the study group was obese and 24 per cent was underweight. There was no difference among mean Injury Severity Score, percent of patients arriving in shock, and mean number of units of packed red blood cells administered during their hospital stay. Obese patients had longer intensive care unit and hospital lengths of stay. There were no differences in ventilator days or mortality. Using univariate statistics, obese patients had increased rates of respiratory and renal failure, bacteremia with and without septic shock, and abdominal wound dehiscence. Subjecting the data to logistic regression analysis, BMI was no longer an independent predictor of any complication. Although obese trauma patients do have increased infectious morbidity, wound dehiscence, and a prolonged length of stay, increased BMI is not an independent predictor of increased morbidity or mortality after trauma laparotomy.

Obesity does not increase morbidity and mortality after laparotomy for trauma

Obesity has been suggested to be a risk factor for increase morbidity and mortality after trauma and surgery. Trauma laparotomy provides an opportunity to assess the effect of body mass index (BMI) on patients subjected to both trauma and surgery. We hypothesized that obesity would have a deleterious effect on outcomes. A retrospective review was conducted of all patients 18 years of age or older undergoing laparotomy for trauma between July 2001 and June 2011. Patients were stratified according to BMI into the following four groups: underweight (16 to 22 kg/m(2)), normal (23 to 27 kg/m(2)), overweight (28 to 34 kg/m(2)), and obese (35 kg/m(2) or higher). Data on the patient's hospital course included length of stay, mortality, respiratory failure, infectious complications, wound dehiscence, and organ failure. A total of 1,297 patients underwent laparotomy. Seven per cent of the study group was obese and 24 per cent was underweight. There was no difference among mean Injury Severity Score, percent of patients arriving in shock, and mean number of units of packed red blood cells administered during their hospital stay. Obese patients had longer intensive care unit and hospital lengths of stay. There were no differences in ventilator days or mortality. Using univariate statistics, obese patients had increased rates of respiratory and renal failure, bacteremia with and without septic shock, and abdominal wound dehiscence. Subjecting the data to logistic regression analysis, BMI was no longer an independent predictor of any complication. Although obese trauma patients do have increased infectious morbidity, wound dehiscence, and a prolonged length of stay, increased BMI is not an independent predictor of increased morbidity or mortality after trauma laparotomy.

Beta Blockade Protection of Bone Marrow Following Injury: A Critical Link between Heart Rate and Immunomodulation

Introduction

Severe trauma induces a profound elevation of catecholamines that is associated with bone marrow (BM) hematopoietic progenitor cell (HPC) colony growth suppression, excessive BM HPC mobilization, and a persistent anemia. Previously, propranolol (BB) use after injury and shock has been shown to prevent this BM dysfunction and improve hemoglobin levels. This study seeks to further investigate the optimal therapeutic dose and timing of BB administration following injury and shock.

Methods

Male Sprague-Dawley rats were subjected to a combined lung contusion (LC), hemorrhagic shock (HS) model ± BB. In our dose response experiments, animals received BB at 1, 2.5, 5, or 10 mg/kg immediately following resuscitation. In our therapeutic window experiments, following LCHS rats were given BB immediately, 1 hour, or 3 hours following resuscitation. BM and peripheral blood (PB) were collected in all animals to measure cellularity, BM HPC growth, circulating HPCs, and plasma G-CSF levels.

Results

Propranolol at 5 and 10 mg/kg significantly reduced HPC mobilization, restored BM cellularity and BM HPC growth, and decreased plasma G-CSF levels. Propranolol at 5 and 10 mg/kg also significantly decreased heart rate. When BB was administered beyond 1 hour after LCHS, its protective effects on cellularity, BM HPC growth, HPC mobilization, and plasma G-CSF levels were greatly diminished.

Conclusion

Early Buse following injury and shock at a dose of at least 5mg/kg is required to maintain BM cellularity and HPC growth, prevent HPC mobilization, and reduce plasma G-CSF levels. This suggests that propranolol exerts its BM protective effect in a dose and time dependent fashion in a rodent model. Finally, heart rate may be a valuable clinical marker to assess effective dosing of propranolol.

Does selective beta-1 blockade provide bone marrow protection after trauma/hemorrhagic shock?

BACKGROUND

Previously, nonselective beta-blockade (BB) with propranolol demonstrated protection of the bone marrow (BM) after trauma and hemorrhagic shock (HS). Because selective beta-1 blockers are used commonly for their cardiac protection, the aim of this study was to more clearly define the role of specific beta adrenergic receptors in BM protection after trauma and HS.

METHODS

Male Sprague-Dawley rats underwent unilateral lung contusion (LC) followed by HS for 45 minutes. After resuscitation, animals were injected with a selective beta-blocker, atenolol (B1B), butoxamine (B2B), or SR59230A (B3B). Animals were killed at 3 hours or 7 days. Heart rate and blood pressure were measured throughout the study period. BM cellularity, growth of hematopoietic progenitor cells (HPCs) in BM, and hemoglobin levels (Hb) were assessed.

RESULTS

Treatment with a B2B or B3B after LCHS restored both BM cellularity and BM HPC colony growth at 3 hours and 7 days. In contrast, treatment with a B1B had no effect on BM cellularity or HPC growth but did decrease heart effectively rate throughout the study. Treatment with a B3B after LCHS increased Hb as compared with LCHS alone.

CONCLUSION

After trauma and HS, protection of BM for 7 days was seen with use of either a selective beta-2 or beta-3 blocker. Use of a selective beta-1 blocker was ineffective in protecting the BM despite a physiologic decrease in heart rate. Therefore, the protection of BM is via the beta-2 and beta-3 receptors and it is not via a direct cardiovascular effect.

Role of bone marrow and mesenchymal stem cells in healing after traumatic injury

BACKGROUND

The role of bone marrow-derived cells (BMDCs) and mesenchymal stem cells (MSC) in healing of traumatic-induced injury remains poorly understood. Mesenteric lymph duct ligation (LDL) results in decreased BMDC mobilization and impaired healing. We hypothesized that LDL-mediated impaired healing would be abrogated by reinjection of BMDC or MSC.

METHODS

Sprague-Dawley rats were subjected to LDL + lung contusion (LC+LDL) with or without injection of BMDCs or MSCs. Unmanipulated control (UC) and lung contusion alone (LC) served as controls. BMDC and MSC homing was assessed by hematopoietic progenitor cell (HPC [granulocyte-, erythrocyte-, monocyte-, and megakaryocyte colony-forming units; erythroid burst-forming units; and erythroid colony-forming units]) colony growth and immunofluorescent microscopic tracking of tagged MSC, respectively. Histologic lung injury score (LIS) was used to grade injury. Data are mean ± SD. *P < .05/Student t test.

RESULTS

Lung HPC growth was decreased in LC+LDL versus LC alone (HPC colonies: 2 ± 2, 4 ± 3, 4 ± 2 vs. 11 ± 2, 20 ± 6, 22 ± 9. *P < .05). LC+LDL had greater degree of lung injury on days 5 and 7 LC alone (LIS: 5 ± 1, 4 ± 1 vs. 3 ± 1, 1 ± 0.4. *P < .05). BMDC injection into rats with LC + LDL increased lung HPC growth to LC level (HPC colonies: 12 ± 2, 19 ± 5, 17 ± 4 vs 11 ± 2, 20 ± 6, 22 ± 9. P > .05). Injected MSCs into LC+LDL rats homed preferentially to contused versus noncontused lung (MSC/high-powered field: 6 ± 4 vs. 2 ± 2 *P < .05). Either BMDC or MSC injection into LC+LDL rats returned lung injury to LC level on day 7 (LIS: 1 ± 0.4 and 1 ± 1 vs. 1 ± 0.4. P > .05).

CONCLUSION

LDL-mediated impaired tissue healing is abrogated by either whole BMDC or MSC injection. This highlights the critical role of BMDC and MSC on healing of trauma-induced injury.

Beta-blockade prevents hematopoietic progenitor cell suppression after hemorrhagic shock

BACKGROUND

Severe injury is accompanied by sympathetic stimulation that induces bone marrow (BM) dysfunction by both suppression of hematopoietic progenitor cell (HPC) growth and loss of cells via HPC mobilization to the peripheral circulation and sites of injury. Previous work demonstrated that beta-blockade (BB) given prior to tissue injury both reduces HPC mobilization and restores HPC colony growth within the BM. This study examined the effect and timing of BB on BM function in a hemorrhagic shock (HS) model.

METHODS

Male Sprague-Dawley rats underwent HS via blood withdrawal, maintaining the mean arterial blood pressure at 30-40 mm Hg for 45 min, after which the extracted blood was reinfused. Propranolol (10 mg/kg) was given either prior to or immediately after HS. Blood pressure, heart rate, BM cellularity, and death were recorded. Bone marrow HPC growth was assessed by counting colony-forming unit-granulocyte-, erythrocyte-, monocyte-, megakaryocyte (CFU-GEMM), burst-forming unit-erythroid (BFU-E), and colony-forming unit-erythroid (CFU-E) cells.

RESULTS

Administration of BB prior to injury restored HPC growth to that of naïve animals (CFU-GEMM 59 ± 11 vs. 61 ± 4, BFU-E 68 ± 9 vs. 73 ± 3, and CFU-E 81 ± 35 vs. 78 ± 14 colonies/plate). Beta-blockade given after HS increased the growth of CFU-GEMM, BFU-E, and CFU-E significantly and improved BM cellularity compared with HS alone. The mortality rate was not increased in the groups receiving BB.

CONCLUSION

Administration of propranolol either prior to injury or immediately after resuscitation significantly reduced post-shock BM suppression. After HS, BB may improve BM cellularity by decreasing HPC mobilization. Therefore, the early use of BB post-injury may play an important role in attenuating the BM dysfunction accompanying HS.

β-blockade protection of bone marrow following trauma: the role of G-CSF

BACKGROUND

Following severe trauma, there is a profound elevation of catecholamine that is associated with a persistent anemic state. We have previously shown that β-blockade (βB) prevents erythroid growth suppression and decreases hematopoietic progenitor cell (HPC) mobilization following injury. Under normal conditions, granulocyte colony stimulating factor (G-CSF) triggers the activation of matrix metalloprotease-9 (MMP-9), leading to the egress of progenitor cells from the bone marrow (BM). When sustained, this depletion of BM cellularity may contribute to BM failure. This study seeks to determine if G-CSF plays a role in the βB protection of BM following trauma.

METHODS

Male Sprague-Dawley rats were subjected to either unilateral lung contusion (LC) ± βB, hemorrhagic shock (HS) ± βB, or both LC/HS ± βB. Propranolol (βB) was given immediately following resuscitation. Animals were sacrificed at 3 and 24 h and HPC mobilization was assessed by evaluating BM cellularity and flow cytometric analysis of peripheral blood for HPCs. The concentration of G-CSF and MMP-9 was measured in plasma by ELISA.

RESULTS

BM cellularity is decreased at 3 h following LC, HS, and LC/HS. HS and LC/HS resulted in significant HPC mobilization in the peripheral blood. The addition of βB restored BM cellularity and reduced HPC mobilization. Three h following HS and LC/HS, plasma G-CSF levels more than double, however LC alone showed no change in G-CSF. βB significantly decreased G-CSF in both HS and LC/HS. Similarly, MMP-9 is elevated following LC/HS, and βB prevents this elevation (390 ± 100 pg/mL versus 275 ± 80 pg/mL).

CONCLUSION

βB protection of the BM following shock and injury may be due to reduced HPC mobilization and maintenance of BM cellularity. Following shock, there is an increase in plasma G-CSF and MMP-9, which is abrogated by βB and suggests a possible mechanism how βB decreases HPC mobilization thus preserving BM cellularity. In contrast, βB protection of BM following LC is not mediated by G-CSF. Therefore, the mechanism of progenitor cell mobilization from the BM is dependent on the type of injury.

Gender Differences in Glucose Variability after Severe Trauma

Gender differences in the physiological response to trauma can affect outcome. Both hyperglycemia and blood glucose (BG) variability predict a poor outcome after trauma. This study examined the hypothesis that both BG levels and the degree of BG variability after trauma are gender-specific and correlate with mortality and morbidity. A retrospective observational cohort study of 1915 trauma patients requiring critical care was performed. Admission BG as well as all BG values obtained during the first week while in the intensive care unit were analyzed. In each patient, the mean BG and the degree of BG variability were calculated. A total of 1560 males and 355 females were studied with an overall mortality rate of 12 per cent. Seventy-six per cent of deaths had a BG greater than 125 mg/dL on admission and as BG variability worsened, the mortality rate also increased. There was a significant difference in male BG variability when comparing survivors with nonsurvivors. Female BG variability did not predict mortality. Failed glucose homeostasis is an important marker of endocrine dysfunction after severe injury. Increased BG variability in males is associated with a higher mortality rate. In females, mortality cannot be predicted based on BG levels or BG variability. These data have significant implications for gender-related differences in postinjury management.