Discovering the truth about life after discharge: Long-term trauma-related mortality

Exploring the impact of traumatic injury on mortality: An analysis of the certified cause of death within one year of serious injury in the Scottish population

BACKGROUND

Few studies effectively quantify the long-term incidence of death following injury. The absence of detailed mortality and underlying cause of death data results in limited understanding and a potential underestimation of the consequences at a population level. This study takes a nationwide approach to identify the one-year mortality following injury in Scotland, evaluating survivorship in relation to pre-existing comorbidities and incidental causes of death.

STUDY DESIGN

This retrospective cohort study assessed the one-year mortality of adult trauma patients with an Injury Severity Score ≥ 9 during 2020 using the Scottish Trauma Audit Group (STAG) registry linked to inpatient hospital data and death certificate records. Patients were divided into three groups: trauma death, trauma-contributed death, and non-trauma death. Kaplan-Meier curves were used for survival analysis to evaluate mortality, and cox proportional hazards regression analysed risk factors linked to death.

RESULTS

4056 patients were analysed with a median age 63 years (58-88) and male predominance (55.2 %). Falls accounted for 73.1 % of injuries followed by motor vehicle accidents (16.3 %) and blunt force (4.9 %). Extremity was the most commonly injured region overall followed by chest and head. However, head injury prevailed in those who died. The registry demonstrated a one-year mortality of 19.3 % with 55 % deaths occurring post-discharge. Of all deaths reported, 35.3 % were trauma deaths, and 47.7 % were trauma-contributed deaths. These groups accounted for over 70 % of mortality within 30 days of hospital admission and continued to represent the majority of deaths up to 6 months post-injury. Patients who died after 6 months were mainly the result of non-traumatic causes, frequently circulatory, neoplastic, and respiratory diseases (37.7 %, 12.3 %, 9.1 %, respectively). Independent risk factors for one-year mortality included a GCS ≤ 8, modified Charlson Comorbidity score >5, Injury Severity Score >25, serious head injury, age and sex.

CONCLUSION

With a one-year mortality of 19.3 %, and post-discharge deaths higher than previously appreciated, patients can face an extended period of survival uncertainty. As mortality due to index trauma lasted up to 6 months post-admission, short-term outcomes fail to represent trauma burden and so cogent survival predictions should be avoided in clinical and patient settings.

Association of Trauma With Long-Term Risk of Death and Immune-Mediated or Cancer Disease in Same-Sex Twins

Importance

Immediate consequences of trauma include a rapid and immense activation of the immune system, whereas long-term outcomes include premature death, physical disability, and reduced workability.

Objective

To investigate if moderate to severe trauma is associated with long-term increased risk of death or immune-mediated or cancer disease.

Design, Setting, and Participants

This registry-based, matched, co-twin control cohort study linked the Danish Twin Registry and the Danish National Patient Registry to identify twin pairs in which 1 twin had been exposed to severe trauma and the other twin had not from 1994 to 2018. The co-twin control design allowed for matching on genetic and environmental factors shared within twin pairs.

Exposure

Twin pairs were included if 1 twin had been exposed to moderate to severe trauma and the other twin had not (ie, co-twin). Only twin pairs where both twins were alive 6 months after the trauma event were included.

Main Outcome and Measure

Twin pairs were followed up from 6 months after trauma until 1 twin experienced the primary composite outcome of death or 1 of 24 predefined immune-mediated or cancer diseases or end of follow-up. Cox proportional hazards regression was used for intrapair analyses of the association between trauma and the primary outcome.

Results

A total of 3776 twin pairs were included, and 2290 (61%) were disease free prior to outcome analysis and were eligible for the analysis of the primary outcome. The median (IQR) age was 36.4 (25.7-50.2) years. The median (IQR) follow-up time was 8.6 (3.8-14.5) years. Overall, 1268 twin pairs (55%) reached the primary outcome; the twin exposed to trauma was first to experience the outcome in 724 pairs (32%), whereas the co-twin was first in 544 pairs (24%). The hazard ratio for reaching the composite outcome was 1.33 (95% CI, 1.19-1.49) for twins exposed to trauma. Analyses of death or immune-mediated or cancer disease as separate outcomes provided hazard ratios of 1.91 (95% CI, 1.68-2.18) and 1.28 (95% CI, 1.14-1.44), respectively.

Conclusion and Relevance

In this study, twins exposed to moderate to severe trauma had significantly increased risk of death or immune-mediated or cancer disease several years after trauma compared with their co-twins.

Fatal opioid overdoses geospatially cluster with level 1 trauma centers in Ohio

OBJECTIVE

Ohio is consistently ranked as one of the worst states for opioid overdose deaths. Traumatic injury has been linked to opioid overdose deaths, yet the location of trauma centers has not been explored. We examined whether geospatial clustering occurred between county-level opioid overdose deaths (OODs) and trauma center levels.

METHODS

We obtained 2019 county-level data from the Ohio Department of Health for fatal overdoses from prescription opioids. We obtained the total number of opioid doses prescribed in 2019 per county from the Ohio Automated Rx Reporting System and American College of Surgeons designated trauma center locations within Ohio from their website. We used geospatial analysis to assess if clustering occurred between trauma center level and prescription opioid overdose deaths at a county level.

RESULTS

There were 42 trauma centers located within 21 counties: 7 counties had level 1, and 14 counties had only level 2/level 3. There was no difference in rates of opioid doses prescribed per 100,000 people between counties with level 1 trauma centers and only level 2/level 3. However, prescription OODs rates were significantly higher in counties with level 1 trauma centers (37.6 vs 20, P = .02). Geospatial clustering was observed between level 1 trauma centers and prescription opioid overdose deaths at the county level (P < .01).

CONCLUSION

Geospatial clustering exists between prescription OODs and level 1 trauma center locations in Ohio. Improved at-risk patient identification and targeted community outreach represent opportunities for trauma providers to tackle the opioid epidemic.

Genetic and immune crosstalk between severe burns and blunt trauma: A study of transcriptomic data

Background: Severe burns and blunt trauma can lead to multiple organ dysfunction syndrome, the leading cause of death in intensive care units. In addition to infection, the degree of immune inflammatory response also affects prognosis. However, the characteristics and clinical relevance of the common mechanisms of these major diseases are still underexplored.

Methods: In the present study, we performed microarray data analysis to identify immune-related differentially expressed genes (DEGs) involved in both disease progression in burns and blunt trauma. Six analyses were subsequently performed, including gene enrichment analysis, protein‐protein interaction (PPI) network construction, immune cell infiltration analysis, core gene identification, co-expression network analysis, and clinical correlation analysis.

Results: A total of 117 common immune-related DEGs was selected for subsequent analyses. Functional analysis emphasizes the important role of Th17 cell differentiation, Th1 and Th2 cell differentiation, Cytokine-cytokine receptor interaction and T cell receptor signaling pathway in these two diseases. Finally, eight core DEGs were identified using cytoHubba, including CD8A, IL10, CCL5, CD28, LCK, CCL4, IL2RB, and STAT1. The correlation analysis showed that the identified core DEGs were more or less significantly associated with simultaneous dysregulation of immune cells in blunt trauma and sepsis patients. Of these, the downregulation of CD8A and CD28 had a worse prognosis.

Conclusion: Our analysis lays the groundwork for future studies to elucidate molecular mechanisms shared in burns and blunt trauma. The functional roles of identified core immune-related DEGs and dysregulated immune cell subsets warrant further in-depth study.

Field Trauma Triage among Older Adults: A Cost-Effectiveness Analysis

BACKGROUND

National guidelines for prehospital trauma triage aim to identify seriously injured patients who may benefit from transport to trauma centers. These guidelines have poor sensitivity for serious injury among older adults. We evaluated the cost-effectiveness of a high-sensitivity triage strategy for older adults.

STUDY DESIGN

We developed a Markov chain Monte Carlo microsimulation model to estimate the cost-effectiveness of high-sensitivity field triage criteria among older adults compared with current practice. The model used a retrospective cohort of 3621 community-dwelling Medicare beneficiaries who were transported by emergency medical services after an acute injury in 7 counties in the northwestern US during January to December 2011. These data informed model estimates of emergency medical services triage assessment, hospital transport patterns, and outcomes from index hospitalization up to 1 year after discharge. Outcomes beyond 1 year were modeled using published literature. Differences in cost and quality-adjusted life years (QALYs) were calculated for both strategies using a lifetime analytical horizon. We calculated the incremental cost-effectiveness ratio (cost per QALY gained) to assess cost-effectiveness, which we defined using a threshold of less than $100,000 per QALY.

RESULTS

High-sensitivity trauma field triage for older adults would produce a small incremental benefit in average trauma system effectiveness (0.0003 QALY) per patient at a cost of $1,236,295 per QALY. Sensitivity analysis indicates that the cost of initial hospitalization and emergency medical services adherence to triage status (ie transporting triage-positive patients to a trauma center) had the largest influence on overall cost-effectiveness.

CONCLUSIONS

High-sensitivity trauma field triage is not cost-effective among older adults.

Chronic critical illness after hypothermia in trauma patients

Objectives

Chronic critical illness (CCI) is a phenotype that occurs frequently in patients with severe injury. Previous work has suggested that inflammatory changes leading to CCI occur early following injury. However, the modifiable factors associated with CCI are unknown. We hypothesized that hypothermia, an early modifiable factor, is associated with CCI.

Methods

To determine the association of hypothermia and CCI, a secondary analysis of the Inflammation and Host Response to Injury database was performed, and subsequently validated on a similar cohort of patients from a single level 1 trauma center from January 2015 to December 2019. Hypothermia was defined as initial body temperature ≤34.5°C. CCI was defined as death or sustained multiorgan failure ≥14 days after injury. Data were analyzed using univariable analyses with Student’s t-test and Pearson’s χ² test, and logistic regression. An arrayed genomic analysis of the transcriptome of circulating immune cells was performed in these patients.

Results

Of the initial 1675 patients, 254 had hypothermia and 1421 did not. On univariable analysis, 120/254 (47.2%) of patients with hypothermia had CCI, compared with 520/1421 (36.6%) without hypothermia who had CCI, p<0.001. On multivariable logistic regression, hypothermia was independently associated with CCI, OR 1.61 (95% CI 1.17 to 2.21) but not mortality. Subsequent validation in 1264 patients of which 172 (13.6%) were hypothermic, verified that hypothermia was independently associated with CCI on multivariable logistic regression, OR 1.84 (95% CI 1.21 to 2.41). Transcriptomic analysis in hypothermic and non-hypothermic patients revealed unique cellular-specific genomic changes to only circulating monocytes, without any distinct effect on neutrophils or lymphocytes.

Conclusions

Hypothermia is associated with the development of CCI in severely injured patients. There are transcriptomic changes which indicate that the changes induced by hypothermia may be associated with persistent CCI. Thus, early reversal of hypothermia following injury may prevent the CCI.

Level of evidence

III.

Seven-year excess mortality, functional outcome and health status after trauma in Hong Kong

PURPOSE

The purpose was to investigate long-term health impacts of trauma and the aim was to describe the functional outcome and health status up to 7 years after trauma.

METHODS

We conducted a prospective, multi-centre cohort study of adult trauma patients admitted to three regional trauma centres with moderate or major trauma (ISS ≥ 9) in Hong Kong (HK). Patients were followed up at regular time points (1, 6 months and 1, 2, 3, 4, 5, 6, and 7 years) by telephone using extended Glasgow Outcome Scale (GOSE) and the Short-Form 36 (SF36). Observed annual mortality rate was compared with the expected mortality rate estimated using the HK population cohort. Linear mixed model (LMM) analyses examined the changes in SF36 with subgroups of age ≥ 65 years, ISS > 15, and GOSE ≥ 5 over time.

RESULTS

At 7 years, 115 patients had died and 48% (138/285) of the survivors responded. The annual mortality rate (AMR) of the trauma cohort was consistently higher than the expected mortality rate from the general population. Forty-one percent of respondents had upper good recovery (GOSE = 8) at 7 years. Seven-year mean PCS and MCS were 45.06 and 52.06, respectively. LMM showed PCS improved over time in patients aged < 65 years and with baseline GOSE ≥ 5, and the MCS improved over time with baseline GOSE ≥ 5. Higher mortality rate, limited functional recovery and worse physical health status persisted up to 7 years post-injury.

CONCLUSION

Long-term mortality and morbidity should be monitored for Asian trauma centre patients to understand the impact of trauma beyond hospital discharge.

Surviving traumatic injury, only to die of acute drug poisoning: Should trauma centers be a path for intervention?

BACKGROUND

Although death from drug overdose is a leading cause of injury-related death in the United States, its incidence after traumatic incident is unknown. Moreover, little is known about related risk factors. We sought to determine the incidence and characteristics of and risk factors for trauma patients suffering death by acute drug poisoning ("overdose") after hospitalization for a traumatic incident.

METHODS

We conducted a retrospective chart review of all admitted trauma patients ≥18 y of age at the only level-1 trauma center in our region from 2012 to 2019, matched with unintentional overdose decedents from the California death registry. We assessed associations between demographic and clinical characteristics with risk of overdose death, using cumulative incidence functions and Fine-Gray subdistribution hazard models.

RESULTS

Of 9,860 patients residing in San Francisco, CA, USA, at the time of their trauma activation or admission during the study period, 1,418 died (4.3 per 100 person-years), 107 from unintentional overdose (0.3 per 100 person-years). Overdose decedents were 84% male, 50% white, with a mean age of 48 years at the time of presentation; 20% of deaths occurred within 3 months of hospitalization, and 40% were attributed to a prescription opioid. In multivariate analysis, younger age, male sex, white race, and having undergone a urine drug screening were all associated with subsequent death from overdose.

CONCLUSION

During a mean 3.4-year follow-up, the mortality rate from overdose among adult patients with traumatic incidents was 0.3/100 person-years. Trauma hospitalization may serve as an opportunity to screen and initiate prevention, harm reduction, and treatment interventions.

Analysis of the Plasma Metabolome after Trauma, Novel Circulating Sphingolipid Signatures, and In-Hospital Outcomes

BACKGROUND

Trauma is the leading cause of death and disability for individuals under age 55. Many severely injured trauma patients experience complicated clinical courses despite appropriate initial therapy. We sought to identify novel circulating metabolomic signatures associated with clinical outcomes following trauma.

STUDY DESIGN

Untargeted metabolomics and circulating plasma immune mediator analysis was performed on plasma collected during 3 post-injury time periods (<6 hours [h], 6 h-24h, day 2-day 5) in critically ill trauma patients enrolled between April 2004 and May 2013 at UPMC Presbyterian Hospital in Pittsburgh, PA. Inclusion criteria were age ≥ 18 years, blunt mechanism, ICU admission, and expected survival ≥ 24 h. Exclusion criteria were isolated head injury, spinal cord injury, and pregnancy. Exploratory endpoints included length of stay (overall and ICU), ventilator requirements, nosocomial infection, and Marshall organ dysfunction (MOD) score. The top 50 metabolites were isolated using repeated measures ANOVA and multivariate empirical Bayesian analysis for further study.

RESULTS

Eighty-six patients were included for analysis. Sphingolipids were enriched significantly (chi-square, p < 10^-6) among the top 50 metabolites. Clustering of sphingolipid patterns identified 3 patient subclasses: nonresponders (no time-dependent change in sphingolipids, n = 41), sphingosine/sphinganine-enhanced (n = 24), and glycosphingolipid-enhanced (n = 21). Compared with the sphingolipid-enhanced subclasses, nonresponders had longer mean length of stay, more ventilator days, higher MOD scores, and higher circulating levels of proinflammatory immune mediators IL-6, IL-8, IL-10, MCP1/CCL2, IP10/CXCL10, and MIG/CXCL9 (all p < 0.05), despite similar Injury Severity Scores (p = 0.12).

CONCLUSIONS

Metabolomic analysis identified broad alterations in circulating plasma sphingolipids after blunt trauma. Circulating sphingolipid signatures and their association with both clinical outcomes and circulating inflammatory mediators suggest a possible link between sphingolipid metabolism and the immune response to trauma.

Short-term versus long-term trauma mortality: A systematic review

BACKGROUND

Trauma is the leading cause of death in the United States for persons under 44 years and the fourth leading cause of death in the elderly. Advancements in clinical care and standardization of treatment protocols have reduced 30-day trauma mortality to less than 4%. However, these improvements do not seem to correlate with long-term outcomes. Some reports have shown a greater than 20% mortality rate when looking at long-term outcomes. The aim of this study was to systematically review the incongruence between short- and long-term mortality for trauma patients.

METHODS

For this systematic review, we searched the Cochrane Library, EMBASE, Ovid Medline, Google Scholar, and Web of Science database to obtain relevant English, German, French, and Portuguese articles from 1965 to 2018.

RESULTS

Trauma patients have decreased long-term survival when compared to the general population and when compared with age-matched cohorts. Postdischarge trauma mortality is significantly higher (mean, 4.6% at 3-6 months, 15.8% at 2-3 years, 26.3% at 5-25 years) compared with controls (mean, 1.3%, 2.2%, and 15.6%, respectively). Patient comorbidities likely contribute to long-term trauma deaths. Trauma patients discharged to a skilled nursing facility have worse mortality compared with those discharged either to home or a rehabilitation center. In contrast to data available which illustrate that short-term mortality has improved, quality of evidence was not sufficient to determine if any improvements in long-term trauma mortality outcomes have also occurred.

CONCLUSIONS

The decreased short-term mortality observed in trauma patients does not appear correlated with decreased long-term mortality. The extent to which increased long-term trauma mortality is related to the initial traumatic insult-versus rising population age and comorbidity burden as well as suboptimal discharge location-requires further study.

LEVEL OF EVIDENCE

Systematic Review, level IV.

Crosstalk between T Helper Cell Subsets and Their Roles in Immunopathogenesis and Outcome of Polytrauma Patients

Purpose

One of the leading causes of morbidity and early-age mortality across the globe is trauma. It disrupts immune system homeostasis and intensely affects the innate and adaptive immune responses, predisposing patients to posttrauma complications and poor outcomes. Most of the studies on posttrauma cellular immune response have been centered on the T helper-1-T helper-2 imbalances after trauma. This study was conducted to understand the role of circulating novel T helper cells in the acute posttraumatic period and clinical outcome of trauma patients.

Materials and methods

Signature cytokines and transcription factors of circulating Th (T helper)-9, Th-17, Th-22, and regulatory T helper cells were studied using flowcytometry along with serum biomarkers in 49 patients with polytraumatic injuries admitted to a tertiary care hospital. The patients were followed up until their outcome. The results were correlated with their clinical outcomes.

Results

In patients who died, higher nTreg, iTreg, Tr1 (early-phase), and higher IRF4+Th-9, IL17+ Th-17, and RORγT+ Th-17 (mid-phase) were seen. However, by the late phase, only RORγT+ Th-17 remained higher. Serum IL-6 and PCT were found to be consistently higher. In survivors, higher Th-3 (early phase), Th-22 (mid-phase), and IRF4+Th-9, IL17+ Th-17, nTreg, Th-3 (late phase) were observed to have played a protective role. Serum IL-2, IL-4, IL-17A and IL-22 were significantly higher in survivors.

Conclusion

Different T helper subsets were observed to be playing pathogenic and protective roles in different phases of trauma and could be used for early prognostication and make way for noninvasive management of critically injured trauma patients by immunomodulation.

How to cite this article

Khurana S, Bhardwaj N, Kumar S, Sagar S, Pal R, Soni KD, et al. Crosstalk between T Helper Cell Subsets and Their Roles in Immunopathogenesis and Outcome of Polytrauma Patients. Indian J Crit Care Med 2020;24(11):1037–1044.

Duration of Respiratory Failure After Trauma Is Not Associated With Increased Long-Term Mortality

OBJECTIVES

Although 1-year survival in medically critically ill patients with prolonged mechanical ventilation is less than 50%, the relationship between respiratory failure after trauma and 1-year mortality is unknown. We hypothesize that respiratory failure duration in trauma patients is associated with decreased 1-year survival.

DESIGN

Retrospective cohort of trauma patients.

SETTING

Single center, level 1 trauma center.

PATIENTS

Trauma patients admitted from 2011 to 2014; respiratory failure is defined as mechanical ventilation greater than or equal to 48 hours, excluded head Abbreviated Injury Score greater than or equal to 4.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Mortality was calculated from the Washington state death registry. Cohort was divided into short (≤ 14 d) and long (> 14 d) ventilation groups. We compared survival with a Cox proportional hazard model and generated a receiver operator characteristic to describe the respiratory failure and mortality relationship. Data are presented as medians with interquartile ranges and hazard ratios with 95% CIs. We identified 1,503 patients with respiratory failure; median age was 51 years (33-65 yr) and Injury Severity Score was 19 (11-29). Median respiratory failure duration was 3 days (2-6 d) with 10% of patients in the long respiratory failure group. Cohort mortality at 1 year was 16%, and there was no difference in mortality between short and long duration of respiratory failure. Predictions for 1-year mortality based on respiratory failure duration demonstrated an area under the receiver operator characteristic curve of 0.57. We determined that respiratory failure patients greater than or equal to 75 years had an increased hazard of death at 1 year, hazard ratio, 6.7 (4.9-9.1), but that within age cohorts, respiratory failure duration did not influence 1-year mortality.

CONCLUSIONS

Duration of mechanical ventilation in the critically injured is not associated with 1-year mortality. Duration of ventilation following injury should not be used to predict long-term survival.

Nonparametric change point estimation for survival distributions with a partially constant hazard rate

We present a new method for estimating a change point in the hazard function of a survival distribution assuming a constant hazard rate after the change point and a decreasing hazard rate before the change point. Our method is based on fitting a stump regression to p values for testing hazard rates in small time intervals. We present three real data examples describing survival patterns of severely ill patients, whose excess mortality rates are known to persist far beyond hospital discharge. For designing survival studies in these patients and for the definition of hospital performance metrics (e.g. mortality), it is essential to define adequate and objective end points. The reliable estimation of a change point will help researchers to identify such end points. By precisely knowing this change point, clinicians can distinguish between the acute phase with high hazard (time elapsed after admission and before the change point was reached), and the chronic phase (time elapsed after the change point) in which hazard is fairly constant. We show in an extensive simulation study that maximum likelihood estimation is not robust in this setting, and we evaluate our new estimation strategy including bootstrap confidence intervals and finite sample bias correction.

Atrial Natriuretic Peptide: A Potential Early Therapy for the Prevention of Multiple Organ Dysfunction Syndrome Following Severe Trauma

Trauma remains a tremendous medical burden partly because of increased expenditure for the management of multiple organ dysfunction syndrome (MODS) developed during hospital stay. The intestinal barrier injury continues to be a second insult resulting in MODS which currently lacks efficient strategies for prevention. Recent studies have uncovered multi-organ protective benefits of atrial natriuretic peptide (ANP) in cardiovascular disease. However, the role of ANP in the prevention of MODS following severe trauma has not been understood. In our laboratory study, 1-h infusion of exogenous ANP during hemorrhagic shock following severe trauma induced high-level expression of endogenous serum ANP after 24 h, this effect was related to the improved level of functional biomarkers in multiple organs. Such phenomenon has not been found in other laboratories. A thorough literature review consequently was performed to uncover the potential mechanisms, to appraise therapy safety, and to propose uncertainties. In severe trauma, short-term exogenous ANP therapy during hemorrhagic shock may promote sustained endogenous expression of ANP from intestinal epithelium through activating a positive feedback loop mechanism involving phospholipase C-γ1 and reactive oxygen species crosstalk. This feedback loop may prevent MODS through multiple signaling pathways. Administration of ANP during hemorrhagic shock is thought to be safe. Further studies are required to confirm our proposed mechanisms and to investigate the dose, duration, and timing of ANP therapy in severe trauma.

One-year and three-year mortality prediction in adult major blunt trauma survivors: a National Retrospective Cohort Analysis

Background

Survivors of trauma are at increased risk of dying after discharge. Studies have found that age, head injury, injury severity, falls and co-morbidities predict long-term mortality. The objective of our study was to build a nomogram predictor of 1-year and 3-year mortality for major blunt trauma adult survivors of the index hospitalization.

Methods

Using data from the Singapore National Trauma Registry, 2011–2013, we analyzed adults aged 18 and over, admitted after blunt injury, with an injury severity score (ISS) of 12 or more, who survived the index hospitalization, linked to death registry data. The study population was randomly divided 60/40 into separate construction and validation datasets, with the model built in the construction dataset, then tested in the validation dataset. Multivariable logistic regression was used to analyze 1-year and 3-year mortality.

Results

Of the 3414 blunt trauma survivors, 247 (7.2%) died within 1 year, and 551 (16.1%) died within 3 years of injury. Age (OR 1.06, 95% CI 1.05–1.07, p < 0.001), male gender (OR 1.53, 95% CI 1.12–2.10, p < 0.01), low fall from 0.5 m or less (OR 3.48, 95% CI 2.06–5.87, p < 0.001), Charlson comorbidity index of 2 or more (OR 2.26, 95% CI 1.38–3.70, p < 0.01), diabetes (OR 1.31, 95% CI 1.68–2.52, p = 0.04), cancer (OR 1.76, 95% CI 0.94–3.32, p = 0.08), head and neck AIS 3 or more (OR 1.79, 95% CI 1.13–2.84, p = 0.01), length of hospitalization of 30 days or more (OR 1.99, 95% CI 1.02–3.86, p = 0.04) were predictors of 1-year mortality. This model had a c-statistic of 0.85. Similar factors were found significant for the model predictor of 3-year mortality, which had a c-statistic of 0.83. Both models were validated on the second dataset, with an overall accuracy of 0.94 and 0.84 for 1-year and 3-year mortality respectively.

Conclusions

Adult survivors of major blunt trauma can be risk-stratified at discharge for long-term support.

Innate immune responses to trauma

Trauma can affect any individual at any location and at any time over a lifespan. The disruption of macrobarriers and microbarriers induces instant activation of innate immunity. The subsequent complex response, designed to limit further damage and induce healing, also represents a major driver of complications and fatal outcome after injury. This Review aims to provide basic concepts about the posttraumatic response and is focused on the interactive events of innate immunity at frequent sites of injury: the endothelium at large, and sites within the lungs, inside and outside the brain and at the gut barrier.

Persistent Inflammation, Immunosuppression and Catabolism Syndrome

Following advances in critical care, in-hospital multiple organ failure-related mortality is declining. Consequently, incidence of chronic critical illness is increasing. These patients linger in the intensive care unit, have high resource utilization, and poor long-term outcomes. Within this population, the authors propose that a substantial subset of patients have a new phenotype: persistent inflammation, immunosuppression, and catabolism syndrome. There is evidence that myelodysplasia with expansion of myeloid-derived suppressor cells, innate and adaptive immune suppression, and protein catabolism with malnutrition are major contributors. Optimal care of these patients will require novel multimodality interventions.

Early exposure to hyperoxia and mortality in critically ill patients with severe traumatic injuries

BACKGROUND

Hyperoxia is common early in the course of resuscitation of critically ill patients. It has been associated with mortality in some, but not all, studies of cardiac arrest patients and other critically ill cohorts. Reasons for the inconsistency are unclear and may depend on unmeasured patient confounders, the timing and duration of hyperoxia, population characteristics, or the way that hyperoxia is defined and measured. We sought to determine whether, in a prospectively collected cohort of mechanically ventilated patients with traumatic injuries with and without head trauma, higher maximum partial pressure of arterial oxygen (PaO2) within 24 hours of admission would be associated with increased risk of in-hospital mortality.

METHODS

Critically ill patients with traumatic injuries undergoing invasive mechanical ventilation enrolled in the Validating Acute Lung Injury biomarkers for Diagnosis (VALID) study were included in this study. All arterial blood gases (ABGs) from the first 24 hours of admission were recorded. Primary analysis was comparison of the highest PaO2 between hospital survivors and non-survivors.

RESULTS

A total of 653 patients were evaluated for inclusion. Of these, 182 were not mechanically ventilated or did not have an ABG measured in the first 24 hours, leaving 471 patients in the primary analysis. In survivors, the maximum PaO2 was 141 mmHg (median, interquartile range 103 - 212) compared to 148 mmHg (IQR 105 - 209) in non-survivors (p = 0.82). In the subgroup with head trauma (n = 266), the maximum PaO2 was 133 mmHg (IQR 97 - 187) among survivors and 152 mmHg (108 - 229) among nonsurvivors (p = 0.19). After controlling for age, injury severity score, number of arterial blood gases, and fraction of inspired oxygen, maximum PaO2 was not associated with increased mortality (OR 1.27 for every fold increase of PaO2 (95% CI 0.72 - 2.25).

CONCLUSIONS

In mechanically ventilated patients with severe traumatic injuries, hyperoxia in the first 24 hours of admission was not associated with increased risk of death or worsened neurological outcomes in a setting without brain tissue oxygenation monitoring.