Smoking in trauma patients: the effects on the incidence of sepsis, respiratory failure, organ failure, and mortality

Survival prediction for heart failure complicated by sepsis: based on machine learning methods

Background

Heart failure is a cardiovascular disorder, while sepsis is a common non-cardiac cause of mortality. Patients with combined heart failure and sepsis have a significantly higher mortality rate and poor prognosis, making early identification of high-risk patients and appropriate allocation of medical resources critically important.

Methods

We constructed a survival prediction model for patients with heart failure and sepsis using the eICU-CRD database and externally validated it using the MIMIC-IV database. Our primary outcome is the 28-day all-cause mortality rate. The Boruta method is used for initial feature selection, followed by feature ranking using the XGBoost algorithm. Four machine learning models were compared, including Logistic Regression (LR), eXtreme Gradient Boosting (XGBoost), Adaptive Boosting (AdaBoost), and Gaussian Naive Bayes (GNB). Model performance was assessed using metrics such as area under the curve (AUC), accuracy, sensitivity, and specificity, and the SHAP method was utilized to visualize feature importance and interpret model results. Additionally, we conducted external validation using the MIMIC-IV database.

Results

We developed a survival prediction model for heart failure complicated by sepsis using data from 3891 patients in the eICU-CRD and validated it externally with 2928 patients from the MIMIC-IV database. The LR model outperformed all other machine learning algorithms with a validation set AUC of 0.746 (XGBoost: 0.726, AdaBoost: 0.744, GNB: 0.722), alongside accuracy (0.685), sensitivity (0.666), and specificity (0.712). The final model incorporates 10 features: age, ventilation, norepinephrine, white blood cell count, total bilirubin, temperature, phenylephrine, respiratory rate, neutrophil count, and systolic blood pressure. We employed the SHAP method to enhance the interpretability of the model based on the LR algorithm. Additionally, external validation was conducted using the MIMIC-IV database, with an external validation AUC of 0.699.

Conclusion

Based on the LR algorithm, a model was constructed to effectively predict the 28-day all-cause mortality rate in patients with heart failure complicated by sepsis. Utilizing our model predictions, clinicians can promptly identify high-risk patients and receive guidance for clinical practice.

Insurance Type and Withdrawal of Life-Sustaining Therapy in Critically Injured Trauma Patients

Importance

Withdrawal of life-sustaining therapy (WLST) decisions for critically injured trauma patients are complicated and multifactorial, with potential for patients' insurance status to affect decision-making.

Objectives

To determine if patient insurance type (private insurance, Medicaid, and uninsured) is associated with time to WLST in critically injured adults cared for at US trauma centers.

Design, Setting, and Participants

This retrospective registry-based cohort study included reported data from level I and level II trauma centers in the US that participated in the American College of Surgeons Trauma Quality Improvement Program (TQIP) registry. Participants included adult trauma patients who were injured between January 1, 2017, and December 31, 2020, and required an intensive care unit stay. Patients were excluded if they died on arrival or in the emergency department or had a preexisting do not resuscitate directive. Analyses were performed on December 12, 2023.

Exposures

Insurance type (private insurance, Medicaid, uninsured).

Main Outcomes and Measures

An adjusted time-to-event analysis for association between insurance status and time to WLST was performed, with analyses accounting for clustering by hospital.

Results

This study included 307 731 patients, of whom 160 809 (52.3%) had private insurance, 88 233 (28.6%) had Medicaid, and 58 689 (19.1%) were uninsured. The mean (SD) age was 40.2 (14.1) years, 232 994 (75.7%) were male, 59 551 (19.4%) were African American or Black patients, and 201 012 (65.3%) were White patients. In total, 12 962 patients (4.2%) underwent WLST during their admission. Patients who are uninsured were significantly more likely to undergo earlier WLST compared with those with private insurance (HR, 1.54; 95% CI, 1.46-1.62) and Medicaid (HR, 1.47; 95% CI, 1.39-1.55). This finding was robust to sensitivity analysis excluding patients who died within 48 hours of presentation and after accounting for nonwithdrawal death as a competing risk.

Conclusions and Relevance

In this cohort study of US adult trauma patients who were critically injured, patients who were uninsured underwent earlier WLST compared with those with private or Medicaid insurance. Based on our findings, patient's ability to pay was may be associated with a shift in decision-making for WLST, suggesting the influence of socioeconomics on patient outcomes.

Association of Cigarette Smoking History With Drug Abuse History and Arterial Carboxyhemoglobin in Trauma Activation Patients: A Retrospective Study

Introduction The relationship between cigarette smoking and arterial carboxyhemoglobin (CoHb) in trauma activation patients has not been investigated. The aim was to determine if cigarette smoking is associated with drug abuse history and arterial CoHb levels. Methodology This is a retrospective review of level I trauma center activations aged 18-60 during 2018-2020. A medical record audit was performed to assess each patient's cigarette smoking and drug abuse history and admission arterial CoHb level. The CoHb levels and smoking history for each patient were used to construct a receiver operating characteristic curve. Results Of the 742 trauma activations aged 18-60, 737 (99.3%) had a documented cigarette smoking history. Smoking history was positive in 49.7% (366) and negative in 50.3% (371). The positive smoking proportion was greater in patients with a drug abuse history (63.9% (234/366)) than those with a negative history (31.0% (115/371); p<0.0001; odds ratio=4.0). In 717 patients with a CoHb value, the CoHb was higher in smokers (3.9±2.2%) than in non-smokers (0.5±0.4%; p<0.0001; Cohen d=2.2). A CoHb >1.5% was higher in smokers (93.3% (333/357)) than non-smokers (1.7% (6/360); p<0.0001; odds ratio=818.6). The receiver operating characteristic curve for the relationship between CoHb and cigarette smoking history showed an area under the curve of 0.980 (p<0.0001). Using an arterial CoHb level >1.5% to predict a positive smoking history and a CoHb level ≤1.5% to predict a non-smoking history, sensitivity was 93.3% (333/357), specificity was 98.3% (354/360), and accuracy was 95.8% (687/717). Conclusion Cigarette smoking in trauma activations aged 18-60 is associated with drug abuse history and increased arterial CoHb levels on trauma center arrival.

Blood Count-Derived Inflammatory Markers Correlate with Lengthier Hospital Stay and Are Predictors of Pneumothorax Risk in Thoracic Trauma Patients

(1) Background: Trauma is one of the leading causes of death worldwide, with the chest being the third most frequent body part injured after abdominal and head trauma. Identifying and predicting injuries related to the trauma mechanism is the initial step in managing significant thoracic trauma. The purpose of this study is to assess the predictive capabilities of blood count-derived inflammatory markers at admission. (2) Materials and Methods: The current study was designed as an observational, analytical, retrospective cohort study. It included all patients over the age of 18 diagnosed with thoracic trauma, confirmed with a CT scan, and admitted to the Clinical Emergency Hospital of Targu Mureş, Romania. (3) Results: The occurrence of posttraumatic pneumothorax is highly linked to age (p = 0.002), tobacco use (p = 0.01), and obesity (p = 0.01). Furthermore, high values of all hematological ratios, such as the NLR, MLR, PLR, SII, SIRI, and AISI, are directly associated with the occurrence of pneumothorax (p < 0.001). Furthermore, increased values of the NLR, SII, SIRI, and AISI at admission predict a lengthier hospitalization (p = 0.003). (4) Conclusions: Increased neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), platelet-to-lymphocyte ratio (PLR), systemic inflammatory index (SII), aggregate inflammatory systemic index (AISI), and systemic inflammatory response index (SIRI) levels at admission highly predict the occurrence of pneumothorax, according to our data.

Age itself or age-associated comorbidities? A nationwide analysis of outcomes of geriatric trauma

PURPOSE

Geriatric trauma patients present physiological challenges to care providers. A nationwide analysis was performed to evaluate the roles of age alone versus age-associated comorbidities in the morbidity and mortality of elderly patients with blunt abdominal trauma (BAT).

METHODS

Patients with BAT registered in the National Trauma Data Bank from 2013 to 2015 were analyzed using propensity score matching (PSM) to evaluate the mortality rate, complication rate, hospital length of stay (LOS), intensive care unit (ICU) LOS and ventilator days between young (age < 65) and elderly (age ≥ 65) patients. An adjusted multivariate logistic regression (MLR) model was also used to evaluate the effect of age itself and age-associated comorbidities on mortality.

RESULTS

There were 41,880 patients with BAT during the study period. In elderly patients, the injury severity score (ISS) decreased with age, but the mortality rate increased inversely (from 5.0 to 13.5%). Under a similar condition and proportion of age-associated comorbidities after a well-batched PSM analysis, elderly patients had significantly higher mortality rates (8.0% vs. 1.9%, p < 0.001), higher complication rates (35.1% vs. 30.6%, p < 0.001), longer hospital LOS (8.9 vs. 8.1 days, p < 0.001), longer ICU LOS (3.7 vs. 2.7 days, p < 0.001) and more ventilator days (1.1 vs. 0.5 days, p < 0.001) than young patients. Furthermore, the MLR analysis showed that age itself served as an independent factor for mortality (odds ratio: 1.049, 95% CI 1.043-1.055, p < 0.001), but age-associated comorbidity was not.

CONCLUSION

In patients with BAT, age itself appeared to have an independent and deleterious effect on mortality, but age-associated comorbidity did not.

Retrospective study on rib fractures: smoking and alcohol matter for mortality and complications

Background

Rib fractures and substance use are both common in trauma patients, but there is little data on how smoking and alcohol use may be associated with outcomes in these patients. We assessed the association between smoking or alcohol use disorder (AUD) and outcomes in patients with rib fractures.

Methods

We used institutional databases to conduct a retrospective review of patients with rib fractures at the only American College of Surgeons-verified adult level 1 trauma center in a rural state between 2015 and 2019. The key exposure variables were smoking and AUD. The key outcome variables were mortality and pulmonary complications (pneumonia, adult respiratory distress syndrome, and pneumothorax). We used multivariable regression for analysis and directed acyclic graphs to identify variables for adjustment.

Results

We identified 1880 eligible patients with rib fractures, including 693 (37%) who were smokers and 204 (11%) who had AUD. Compared with non-smokers, smokers were younger, more often male, and had lower mortality rates. Regression showed that smokers had a lower likelihood of mortality (OR 0.48; 95% CI 0.27 to 0.87; p=014). Likelihood of pneumonia, ARDS, and pneumothorax was not different between smokers and non-smokers. Compared with patients without AUD, patients with AUD were older, more often male, and had higher likelihood of pneumonia and lower likelihood of pneumothorax. Regression showed that patients with AUD had higher likelihood of pneumonia (OR 1.82; 95% CI 1.24 to 2.68; p=0.002) and lower likelihood of pneumothorax (OR 0.51; 95% CI 0.33 to 0.75; p=0.002).

Discussion

In trauma patients with rib fractures treated at a level 1 trauma center over 5 years, smoking was associated with decreased risk of mortality. These findings have implications for risk stratification and clinical decision-making for patients with rib fractures.

Level of evidence

III

Adult Bicycle Collisions: Impact of Helmet Use on Head and Cervical Spine Injury

BACKGROUND

No states currently require adult bicycle riders to wear helmets. Opponents of a universal helmet law argue that helmets may cause a greater torque on the neck during collisions, potentially increasing the risk of cervical spine fracture (CSF). This assumption has not been supported by data for motorcyclists. Therefore, we sought to evaluate the risk of CSF and cervical spinal cord injury (CSCI) in helmeted bicyclists (HBs) versus nonhelmeted bicyclists (NHBs) involved in collisions. We hypothesize that in adult HBs, there is an increased incidence of CSF and injury but lower rates of severe head injury and mortality than in NHBs.

MATERIALS AND METHODS

The Trauma Quality Improvement Program (2010-2016) was queried for adult bicyclists involved in collisions, comparing HBs with NHBs. A multivariable logistic regression model was used for analysis.

RESULTS

Of 25,047 bicyclists, 14,234 (56.8%) were NHBs. NHBs were more often black (13.3% versus 2.3%, P < 0.001) and screened positive for alcohol on admission (25.7% versus 4.6%, P < 0.001). NHBs had lower rates of CSF (17.7% versus 23.7%, P < 0.001) and CSCI (1.1% versus 1.9%, P < 0.001) but higher rates of mortality (4.9% versus 2.2%, P < 0.001) and a higher risk for severe head injury (odds ratio [OR]: 2.26, 2.13-2.40, P < 0.001). After adjusting for covariates, NHBs had a higher risk of mortality (OR: 2.38, 2.00-2.84, P < 0.001) but lower risk of CSF (OR: 0.66 0.62-0.71, P < 0.001) and CSCI (OR: 0.53, 0.42-0.68, P < 0.001).

CONCLUSIONS

HBs involved in collisions have a higher risk of CSF and CSCI; however, NHBs have a higher risk of severe head injury and mortality. Consideration for a universal helmet law among bicyclists and ongoing research regarding helmet development is needed.

The effects of smoking on adolescent trauma patients: a propensity-score-matched analysis

PURPOSE

Cigarettes have been demonstrated to be toxic to the pulmonary connective tissue by impairing the lung's ability to clear debris, resulting in infection and acute respiratory distress syndrome (ARDS). Approximately 8% of adolescents are smokers. We hypothesized that adolescent trauma patients who smoke have a higher rate of ARDS and pneumonia when compared to non-smokers.

METHODS

The Trauma Quality Improvement Program (2014-2016) was queried for adolescent trauma patients aged 13-17 years. Adolescent smokers were 1:2 propensity-score-matched to non-smokers based on age, comorbidities, and injury type. Data were analyzed using chi square for categorical data and Mann-Whitney U test for continuous data.

RESULTS

From 32,610 adolescent patients, 997 (3.1%) were smokers. After matching, 459 smokers were compared to 918 non-smokers. There were no differences in matched characteristics. Compared to non-smokers, smokers had an increased rate of pneumonia (3.1% vs. 1.1%, p = 0.01) but not ARDS (0.2% vs. 0%, p = 0.16). Compared to the non-smoking group, the smokers had a longer median total hospital length-of-stay (3 vs. 2 days, p = 0.01) and no difference in overall mortality (1.5% vs. 2.4%, p = 0.29).

CONCLUSION

Smoking is associated with an increased rate of pneumonia in adolescent trauma patients. Future research should target smoking cessation and/or interventions to mitigate the deleterious effects of smoking in this population.

Smoking is associated with an improved short-term outcome in patients with rib fractures

BACKGROUND

Smokers with cardiovascular disease have been reported to have decreased mortality compared to non-smokers. Rib fractures are associated with significant underlying injuries such as lung contusions, lacerations, and/or pneumothoraces. We hypothesized that blunt trauma patients with rib fractures who are smokers have decreased ventilator days and risk of in-hospital mortality compared to non-smokers.

STUDY DESIGN

The Trauma Quality Improvement Program (2010-2016) was queried for patients presenting with a blunt rib fracture. Patients that died within 24 h of admission were excluded. A multivariable logistic regression model was performed.

RESULTS

From 282,986 patients with rib fractures, 57,619 (20.4%) were smokers. Compared to non-smokers with rib fractures, smokers had a higher median injury severity score (17 vs. 16, p < 0.001). Smokers had a higher rate of pneumonia (7.5% vs. 6.6%, p < 0.001), however, less ventilator days (5 vs. 6, p = 0.04), and lower in-hospital mortality rate (2.3% vs. 4.6%, p < 0.001), compared to non-smokers. After controlling for covariates, smokers with rib fractures were associated with a decreased risk for in-hospital mortality compared to non-smokers with rib fractures (OR 0.64, 0.56-0.73, p < 0.001).

CONCLUSION

Despite having more severe injuries and increased rates of pneumonia, smokers with rib fractures were associated with nearly a 40% decreased risk of in-hospital mortality and one less ventilator day compared to non-smokers. The long-term detrimental effects of smoking have been widely established. However, the biologic and pathophysiologic adaptations that smokers have may confer a survival benefit when recovering in the hospital from chest wall trauma. This study was limited by the database missing the number of pack-years smoked. Future prospective studies are needed to confirm this association and elucidate the physiologic mechanisms that may explain these findings.

Progress of Research in Neonatal Sepsis

Neonatal sepsis remains a significant global problem with little progress made despite major efforts. At present, there is a lack of an accepted international consensus on the definition, diagnosis, and treatment of neonatal sepsis; the unclear understanding of the pathogenesis of neonatal sepsis leads to blindness in treatment, which will result in an unsatisfactory therapeutic outcome. In addition, some serious diseases caused by noninfectious factors, such as trauma, stress, asphyxia, and so on, have very similar pathophysiological results with neonatal sepsis. In this review we synthesize the recent advances in definition, incidence, causative agents, risk factors, pathophysiology, clinical manifestations, and diagnosis and treatment of neonatal sepsis. Of course, there are still many challenges to neonatal sepsis in many ways.

Outcomes of patients with systolic heart failure presenting with sepsis to the emergency department of a tertiary hospital: a retrospective chart review study from Lebanon

OBJECTIVES

Patients with congestive heart failure (CHF) may be at a higher risk of mortality from sepsis than patients without CHF due to insufficient cardiovascular reserves during systemic infections. The aim of this study is to compare sepsis-related mortality between CHF and no CHF in patients presenting to a tertiary medical centre.

DESIGN

A single-centre, retrospective, cohort study.

SETTING

Conducted in an academic emergency department (ED) between January 2010 and January 2015. Patients' charts were queried via the hospital's electronic system. Patients with a diagnosis of sepsis were included. Descriptive analysis was performed on the demographics, characteristics and outcomes of patients with sepsis of the study population.

PARTICIPANTS

A total of 174 patients, of which 87 (50%) were patients with CHF.

PRIMARY AND SECONDARY OUTCOMES

The primary outcome of the study was in-hospital mortality. Secondary outcomes included intensive care unit (ICU) and hospital lengths of stay, and differences in interventions between the two groups.

RESULTS

Patients with CHF had a higher in-hospital mortality (57.5% vs 34.5%). Patients with sepsis and CHF had higher odds of death compared with the control population (OR 2.45; 95% CI 1.22 to 4.88). Secondary analyses showed that patients with CHF had lower instances of bacteraemia on presentation to the ED (31.8% vs 46.4%). They had less intravenous fluid requirements in first 24 hours (2.75±2.28 L vs 3.67±2.82 L, p =0.038), had a higher rate of intubation in the ED (24.2% vs 10.6%, p=0.025) and required more dobutamine in the first 24 hours (16.1% vs 1.1%, p<0.001). ED length of stay was found to be lower in patients with CHF (15.12±24.45 hours vs 18.17±26.13 hours, p=0.418) and they were more likely to be admitted to the ICU (59.8% vs 48.8%, p=0.149).

CONCLUSION

Patients with sepsis and CHF experienced an increased hospital mortality compared with patients without CHF.

Protective Effect of Nicotine on Sepsis-Induced Oxidative Multiorgan Damage: Role of Neutrophils

Introduction

Despite its adverse health consequences, tobacco smoking is associated with lower incidence of several neurodegenerative and inflammatory diseases. The present study is aimed to show the effects of nicotine, major tobacco constituent, on five organs targeted by sepsis.

Methods

Male Wistar albino rats received tap water with (5mg/kg) or without nicotine for 14 days. Under ketamine anesthesia, sepsis (n = 50) was induced by ligation and puncture of the cecum, while sham group (n = 8) had only laparotomy. In other rats, nicotine drink was withdrawn for 5 days before sepsis induction, while in acute nicotine group, rats were injected with nicotine (30mg/kg, i.p.) before sepsis, but had no oral intake. Rats were decapitated 24 hours after surgery to obtain lung, liver, ileum, heart, and kidney tissues to determine malondialdehyde (MDA) and glutathione (GSH) levels and myeloperoxidase (MPO) activities. Data were analyzed by one-way analysis of variance and Tukey multiple comparison tests or Student's t test.

Results

Chronic nicotine administration or its withdrawal reduced lipid peroxidation and MPO activity and prevented GSH depletion with some varying results in different target tissues. Nicotine injection prior to sepsis depressed MPO activity in all tissues and reduced MDA levels except for the lung, while GSH levels were elevated only in the hepatic and ileal tissues. Histologically observed injury was ameliorated by all nicotine treatments at varying degrees.

Conclusions

The findings of the present study indicate that long-term nicotine administration reduces sepsis-induced oxidative damage in several tissues, which appears to involve inhibition of neutrophil activity in the inflamed tissues.

Implications

Nicotine administration or its withdrawal reduced lipid peroxidation and neutrophil content and prevented GSH depletion with some varying results in different target tissues. A single injection prior to sepsis induction depressed MPO activity in all the tissues and reduced all tissue MDA levels except for the lung. When nicotine was withdrawn for 5 days, its inhibitory effect on MPO activity was still present in all the tissues except for the liver. Microscopically an improved inflammatory response was observed in all the tissues of rats that have received different nicotine pretreatment regimens.

Effects of cigarette smoke on pulmonary endothelial cells

Cigarette smoking is the leading cause of preventable disease and death in the United States. Cardiovascular comorbidities associated with both active and secondhand cigarette smoking indicate the vascular toxicity of smoke exposure. Growing evidence supports the injurious effect of cigarette smoke on pulmonary endothelial cells and the roles of endothelial cell injury in development of acute respiratory distress syndrome (ARDS), emphysema, and pulmonary hypertension. This review summarizes results from studies of humans, preclinical animal models, and cultured endothelial cells that document toxicities of cigarette smoke exposure on pulmonary endothelial cell functions, including barrier dysfunction, endothelial activation and inflammation, apoptosis, and vasoactive mediator production. The discussion is focused on effects of cigarette smoke-induced endothelial injury in the development of ARDS, emphysema, and vascular remodeling in chronic obstructive pulmonary disease.

Do Patients with Pre-Existing Psychiatric Illness Have an Increased Risk of Infection after Injury?

BACKGROUND

Trauma remains a leading cause of death and long term-morbidity. We have shown that patients who sustain traumatic injuries are at increased risk for the development of infectious complications. Psychiatric illnesses (PIs) are also noted to occur frequently among the general population. The presence of a PI has been shown to be a risk factor for the development of infections. Despite the prevalence of both traumatic injuries and psychiatric diseases, there are little data relating the impact of PI on the outcome of patients with trauma. We hypothesize that the presence of a PI will be associated with an increased risk of an infection developing after injury.

PATIENTS AND METHODS

This is a five year retrospective chart review of all admitted patients with trauma age 18 years and older. Patients with and without a major psychiatric illness were compared. Demographic data, mechanism of injury and Injury Severity Score (ISS) were reviewed. Co-morbidities included diabetes mellitus, obesity, pre-injury steroid use, and International Classification of Diseases, 9th edition, based psychiatric illness. All infections were diagnosed by microbiologic criteria (urinary tract infection [UTI], ventilator-associated pneumonia) or Centers for Disease Control and Prevention criteria for clinically evident infections (surgical site infection).

RESULTS

Of the 11,147 admitted trauma patients, 14.5% had a pre-injury PI diagnosis. The PI patients were older (61.5 ± 0.5 vs. 54.3; p < 0.001), more often female (56% vs. 39.1%; p < 0.001), and had no difference in blunt mechanism rates (88.4% vs. 89.9%; p = 0.06) or median ISS (9 vs. 9; p = 0.06). There was no difference between PI and non-PI patients in pre-injury diabetes mellitus (13.4% vs. 12.7%; p = 0.4), steroid use (2.5% vs. 1.9%; p = 0.1), but patients with PI were more likely to be obese (15.7% vs. 13.6%; p = 0.03). Patients with PI were more likely to have an infection develop (10.4% vs. 7.5%; p < 0.001). The most common infection in both groups was UTI (6.9% vs. 4.2%; p < 0.001). Compared with non-PI patients, adjusting for age, gender, ISS, diabetes mellitus, and obesity, patients with PI were more likely to have an infection develop (odds ratio 1.3, 95% confidence interval = 1.1-1.5) Conclusions: Patients with an underlying PI are at increased risk of having a UTI after traumatic injury. This study identifies a previously unknown independent risk factor for UTIs in patients with trauma. This stresses the need for increased awareness and attention to this vulnerable population.

Mitochondrial Dysfunction and Immune Cell Metabolism in Sepsis

Sepsis is a life threatening condition mediated by systemic infection, but also triggered by hemorrhage and trauma. These are significant causes of organ injury implicated in morbidity and mortality, as well as post-sepsis complications associated with dysfunction of innate and adaptive immunity. The role of cellular bioenergetics and loss of metabolic plasticity of immune cells is increasingly emerging in the pathogenesis of sepsis. This review describes mitochondrial biology and metabolic alterations of immune cells due to sepsis, as well as indicates plausible therapeutic opportunities.

Complications and in-hospital mortality in trauma patients treated in intensive care units in the United States, 2013

BACKGROUND

Traumatic injury is a leading cause of morbidity and mortality worldwide, but epidemiologic data about trauma patients who require intensive care unit (ICU) admission are scant. This study aimed to describe the annual incidence of ICU admission for adult trauma patients, including an assessment of risk factors for hospital complications and mortality in this population.

METHODS

This was a retrospective study of adults hospitalized at Level 1 and Level 2 trauma centers after trauma and recorded in the National Trauma Data Bank in 2013. Multiple logistic regression analyses were performed to determine predictors of hospital complications and hospital mortality for those who required ICU admission.

RESULTS

There were an estimated total of 1.03 million ICU admissions for trauma at Level 1 and Level 2 trauma centers in the United States in 2013, yielding an annual incidence of 3.3 per 1000 population. The annual incidence was highest in men (4.6 versus 1.9 per 100,000 for women), those aged 80 years or older (7.8 versus 3.6-4.3 per 100,000 in other age groups), and residents in the Western US Census region (3.9 versus 2.7 to 3.6 per 100,000 in other regions). The most common complications in patients admitted to the ICU were pneumonia (10.9 %), urinary tract infection (4.7 %), and acute respiratory distress syndrome (4.4 %). Hospital mortality was significantly higher for ICU patients who developed one or more complications (16.9 % versus 10.7 % for those who did not develop any complications, p < 0.001).

CONCLUSIONS

Admission to the ICU after traumatic injury is common, and almost a quarter of these patients experience hospital complications. Hospital complications are associated with significantly increased risk of mortality.

Double-hit mouse model of cigarette smoke priming for acute lung injury

Epidemiological studies indicate that cigarette smoking (CS) increases the risk and severity of acute lung injury (ALI)/acute respiratory distress syndrome (ARDS). The mechanism is not understood, at least in part because of lack of animal models that reproduce the key features of the CS priming process. In this study, using two strains of mice, we characterized a double-hit mouse model of ALI induced by CS priming of injury caused by lipopolysaccharide (LPS). C57BL/6 and AKR mice were preexposed to CS briefly (3 h) or subacutely (3 wk) before intratracheal instillation of LPS and ALI was assessed 18 h after LPS administration by measuring lung static compliance, lung edema, vascular permeability, inflammation, and alveolar apoptosis. We found that as little as 3 h of exposure to CS enhanced LPS-induced ALI in both strains of mice. Similar exacerbating effects were observed after 3 wk of preexposure to CS. However, there was a strain difference in susceptibility to CS priming for ALI, with a greater effect in AKR mice. The key features we observed suggest that 3 wk of CS preexposure of AKR mice is a reproducible, clinically relevant animal model that is useful for studying mechanisms and treatment of CS priming for a second-hit-induced ALI. Our data also support the concept that increased susceptibility to ALI/ARDS is an important adverse health consequence of CS exposure that needs to be taken into consideration when treating critically ill individuals.

Implementation of a quality improvement project on smoking cessation reduces smoking in a high risk trauma patient population

BACKGROUND

Cigarette smoking causes about one of every five deaths in the U.S. each year. In 2013 the prevalence of smoking in our institution's trauma population was 26.7 %, well above the national adult average of 18.1 % according to the CDC website. As a quality improvement project we implemented a multimodality smoking cessation program in a high-risk trauma population.

METHODS

All smokers with independent mental capacity admitted to our level I trauma center from 6/1/2014 until 3/31/2015 were counseled by a physician on the benefits of smoking cessation. Those who wished to quit smoking were given further counseling by a pulmonary rehabilitation nurse and offered nicotine replacement therapy (e.g. nicotine patch). A planned 30 day or later follow-up was performed to ascertain the primary endpoint of the total number of patients who quit smoking, with a secondary endpoint of reduction in the frequency of smoking, defined as at least a half pack per day reduction from their pre-intervention state.

RESULTS

During the 9 month study period, 1066 trauma patients were admitted with 241 (22.6 %) identified as smokers. A total of 31 patients with a mean Injury Severity Score (ISS) of 14.2 (range 1-38), mean age of 47.6 (21-71) and mean years of smoking of 27.1 (2-55), wished to stop smoking. Seven of the 31 patients, (22.5 %, 95 % confidence interval [CI] of 10-41 %) achieved self-reported smoking cessation at or beyond 30 days post discharge. An additional eight patients (25.8 %, 95 % CI 12-45 %) reported significant reduction in smoking.

CONCLUSIONS

Trauma patients represent a high risk smoking population. The implementation of a smoking cessation program led to a smoking cessation rate of 22.5 % and smoking reduction in 25.8 % of all identified smokers who participated in the program. This is a relatively simple, inexpensive intervention with potentially far reaching and beneficial long-term health implications. A larger, multi-center prospective study appears warranted.

LEVEL OF EVIDENCE

Therapeutic Study, Level V evidence.

Moderate/severe acute respiratory distress syndrome in patients with or without traumatic brain injury

Introduction

Patients with traumatic brain injury are at risk of developing acute respiratory distress syndrome, which significantly increases morbidity. This study aimed to assess functional difference (respiratory mechanics) and morbidity and mortality of moderate/severe acute respiratory distress syndrome among patients with traumatic brain injury compared with those with other non-traumatic aetiologies, besides assessing the outcomes of patients with severe traumatic brain injury with or without moderate/severe acute respiratory distress syndrome.

Methods

A prospective cohort study analysed consecutive patients with moderate/severe acute respiratory distress syndrome (PaO2/FiO2 < 200) and consecutive patients with traumatic brain injury during a 14-month period in the general intensive care unit of a teaching hospital in Cascavel, southern Brazil.

Results

Overall, 85 patients were assessed: 30 with traumatic brain injury without acute respiratory distress syndrome, 17 with traumatic brain injury and acute respiratory distress syndrome and 38 with non-traumatic brain injury (other aetiologies) acute respiratory distress syndrome. Acute respiratory distress syndrome in patients with traumatic brain injury resulted in a longer intensive care unit length of stay and slightly higher mortality. When acute respiratory distress syndrome patients with and without traumatic brain injury are compared, the latter required higher values of positive end expiratory pressure and showed a trend to lower lung static compliance, with slightly higher mortality.

Conclusions

In patients with traumatic brain injury, the presence of acute respiratory distress syndrome increased hospitalisation time. Patients with non-traumatic brain injury acute respiratory distress syndrome showed lower respiratory compliance and required higher values of positive end expiratory pressure than those with traumatic brain injury – acute respiratory distress syndrome, with higher mortality.

"Smoker's Paradox" in Patients Treated for Severe Injuries: Lower Risk of Mortality After Trauma Observed in Current Smokers

BACKGROUND

Studies evaluating the effect of smoking status on mortality outcomes in trauma patients have been limited, despite the fact that survival benefits of smoking have been reported in other critical care settings. The phenomenon "smoker's paradox" refers to the observation that following acute cardiovascular events, such as acute myocardial infarction and cardiac arrest, smokers often experience decreased mortality in the hospital setting. The objective of our study was to determine whether smoking imparts a survival benefit in patients with traumatic injuries.

METHODS

We performed a retrospective cohort study that analyzed cases included in the National Trauma Data Bank research dataset. Hierarchical logistic regression analyses were used to determine whether smoking alters the risk of mortality and complications in patients who smoke.

RESULTS

The percentage of patients experiencing mortality differed significantly between smokers (n = 38,564) and nonsmokers (n = 319,249) (1.8% vs. 4.3%, P < .001); however, the percentage experiencing a major complication did not (9.7% vs. 9.6%, P = .763). Regression analyses indicated that smokers were significantly less likely to die during the hospital stay compared to nonsmokers after adjusting for individual and hospital factors (OR = 0.15; CI = 0.10, 0.22). Additionally, smokers were also less likely to develop a major complication than nonsmokers (OR = 0.73, CI = 0.59-0.91).

CONCLUSIONS

Patients who smoke appear to have a much lower risk of in-hospital mortality than nonsmokers. Further investigation into biological mechanisms responsible for this effect should be carried out in order to potentially develop therapeutic applications.

Predictors of long-term mortality after severe sepsis in the elderly

BACKGROUND

Mortality rates after severe sepsis are extremely high, and the main focus of most research is short-term mortality, which may not be associated with long-term outcomes. The purpose of this study was to examine long-term mortality after a severe sepsis and identify factors associated with this mortality.

METHODS

The authors performed a population-based study using Veterans' Affairs administrative data of patients aged 65 years and older. The outcome of interest was mortality > 90 days following hospitalization. Our primary analyses were Cox proportional hazard models to examine specific risk factors for long-term mortality.

RESULTS

There were 2,727 patients that met the inclusion criteria. Overall mortality was 55%, and 1- and 2-year mortality rates were 31% and 43%, respectively. Factors significantly associated with long-term mortality included congestive heart failure, peripheral vascular disease, dementia, diabetes with complications and use of mechanical ventilation. Smoking cessation and cardiac medications were associated with decreased long-term mortality rates.

CONCLUSIONS

The authors identified several factors, including receipt of mechanical ventilation, which were significantly associated with increased long-term mortality for survivors of severe sepsis. This information will help clinicians discuss prognosis with patients and their families.

The impact of comorbid [corrected] conditions on critical illness

OBJECTIVE

To review the current knowledge of common comorbidities in the intensive care unit, including diabetes mellitus, chronic obstructive pulmonary disease, cancer, end-stage renal disease, end-stage liver disease, HIV infection, and obesity, with specific attention to epidemiology, contribution to diseases and outcomes, and the impact on treatments in these patients.

DATA SOURCE

Review of the relevant medical literature for specific common comorbidities in the critically ill.

RESULTS

Critically ill patients are admitted to the intensive care unit for various reasons, and often the admission diagnosis is accompanied by a chronic comorbidity. Chronic comorbid conditions commonly seen in critically ill patients may influence the decision to provide intensive care unit care, decisions regarding types and intensity of intensive care unit treatment options, and outcomes. The presence of comorbid conditions may predispose patients to specific complications or forms of organ dysfunction. The impact of specific comorbidities varies among critically ill medical, surgical, and other populations, and outcomes associated with certain comorbidities have changed over time. Specifically, outcomes for patients with cancer and HIV have improved, likely related to advances in therapy. Overall, the negative impact of chronic comorbidity on survival in critical illness may be primarily influenced by the degree of organ dysfunction or the cumulative severity of multiple comorbidities.

CONCLUSION

Chronic comorbid conditions are common in critically ill patients. Both the acute illness and the chronic conditions influence prognosis and optimal care delivery for these patients, particularly for adverse outcomes and complications influenced by comorbidities. Further work is needed to fully determine the individual and combined impact of chronic comorbidities on intensive care unit outcomes.

Cigarette smoke causes lung vascular barrier dysfunction via oxidative stress-mediated inhibition of RhoA and focal adhesion kinase

Cigarette smoke (CS) is a major cause of chronic lung and cardiovascular diseases. Recent studies indicate that tobacco use is also a risk factor for acute lung injury (ALI) associated with blunt trauma. Increased endothelial cell (EC) permeability is a hallmark of ALI. CS increases EC permeability in vitro and in vivo; however, the underlying mechanism is not well understood. In this study, we found that only 6 h of exposure to CS impaired endothelial barrier function in vivo, an effect associated with increased oxidative stress in the lungs and attenuated by the antioxidant N-acetylcysteine (NAC). CS also exacerbated lipopolysaccharide (LPS)-induced increase in vascular permeability in vivo. Similar additive effects were also seen in cultured lung EC exposed to cigarette smoke extract (CSE) and LPS. We further demonstrated that CSE caused disruption of focal adhesion complexes (FAC), F-actin fibers, and adherens junctions (AJ) and decreased activities of RhoA and focal adhesion kinase (FAK) in cultured lung EC. CSE-induced inhibition of RhoA and FAK, endothelial barrier dysfunction, and disassembly of FAC, F-actin, and AJ were prevented by NAC. In addition, the deleterious effects of CSE on FAC, F-actin fibers, and AJ were blunted by overexpression of constitutively active RhoA and of FAK. Our data indicate that CS causes endothelial barrier dysfunction via oxidative stress-mediated inhibition of RhoA and FAK.

Alcohol and risk of admission to hospital for unintentional cutting or piercing injuries at home: a population-based case-crossover study

Background

Cutting and piercing injuries are among the leading causes of unintentional injury morbidity in developed countries. In New Zealand, cutting and piercing are second only to falls as the most frequent cause of unintentional home injuries resulting in admissions to hospital among people aged 20 to 64 years. Alcohol intake is known to be associated with many other types of injury. We used a case-crossover study to investigate the role of acute alcohol use (i.e., drinking during the previous 6 h) in unintentional cutting or piercing injuries at home.

Methods

A population-based case-crossover study was conducted. We identified all people aged 20 to 64 years, resident in one of three regions of the country (Greater Auckland, Waikato and Otago), who were admitted to public hospital within 48 h of an unintentional non-occupational cutting or piercing injury sustained at home (theirs or another's) from August 2008 to December 2009. The main exposure of interest was use of alcohol in the 6-hour period before the injury occurred and the corresponding time intervals 24 h before, and 1 week before, the injury. Other information was collected on known and potential confounders. Information was obtained during face-to-face interviews with cases, and through review of their medical charts.

Results

Of the 356 participants, 71% were male, and a third sustained injuries from contact with glass. After adjustment for other paired exposures, the odds ratio for injury after consuming 1 to 3 standard drinks of alcohol during the 6-hour period before the injury (compared to the day before), compared to none, was 1.77 (95% confidence interval 0.84 to 3.74), and for four or more drinks was 8.68 (95% confidence interval 3.11 to 24.3). Smokers had higher alcohol-related risks than non-smokers.

Conclusions

Alcohol consumption increases the odds of unintentional cutting or piercing injury occurring at home and this risk increases with higher levels of drinking.