Alcohol consumption and development of acute respiratory distress syndrome: a population-based study

Ethanol promotes protease activated receptor 1: Chemokine (C-X-C motif) receptor 4 heteromerization and enhances thrombin-induced impairment of human lung endothelial cell barrier function

Ethanol enhances the propensity of PAR1 and CXCR4 to form heteromers. Ethanol increases PAR1:CXCR4 heteromer expression in human lung microvascular endothelial cells (HULEC-5a). Ethanol enhances the efficacy of PAR1 to activate Gα12 upon thrombin stimulation in cells co-expressing CXCR4. Ethanol dose-dependently increases the efficacy of thrombin to impair HULEC-5a barrier function at clinically relevant concentrations. Interference with PAR1:CXCR4 heteromerization mitigates effects of ethanol on thrombin-induced impairment of HULEC-5a barrier function. Our findings provide a molecular mechanism that is likely to contribute to the increased risk of acute respiratory distress syndrome with alcohol abuse.

Causal Associations Between Tobacco, Alcohol Use and Risk of Infectious Diseases: A Mendelian Randomization Study

INTRODUCTION

The causal effects of smoking and alcohol use on the risk of infectious diseases are unclear, and it is hard investigate them in an observational study due to the potential confounding factors. The aim of this study was to use Mendelian randomization (MR) techniques to assess the causalities between smoking, alcohol use and risk of infectious diseases.

METHODS

Univariable and multivariable MR analyses were performed using genome-wide association data for the age of initiation of regular smoking (AgeSmk, N = 341,427), smoking initiation (SmkInit, N = 1,232,091), cigarettes per day (CigDay, N = 337,334), lifetime smoking (LifSmk, N = 462,690), drinks per week (DrnkWk, N = 941,280), sepsis (N = 486,484), pneumonia (N = 486,484), upper respiratory tract infection (URTI, N = 486,484) and urinary tract infection (UTI, N = 486,214) among individuals of European ancestry. Independent genetic variants that were significantly (P < 5 × 10^-8) associated with each exposure were considered as instruments. The inverse-variance-weighted method was used in the primary analysis, which was followed by a series of sensitivity analyses.

RESULTS

Genetically predicted SmkInit was associated with an increased risk of sepsis (OR 1.353, 95% CI 1.079-1.696, P = 0.009), pneumonia (OR 1.770, 95% CI 1.464-2.141, P = 3.8 × 10^-9) and UTI (OR 1.445, 95% CI 1.184-1.764, P = 3 × 10^-4). Moreover, genetically predicted CigDay was associated with a higher risk of sepsis (OR 1.403, 95% CI 1.037-1.898, P = 0.028) and pneumonia (OR 1.501, 95% CI 1.167-1.930, P = 0.00156). Furthermore, genetically predicted LifSmk was associated with an increased risk of sepsis (OR 2.200, 95% CI 1.583-3.057, P = 2.63 × 10^-6), pneumonia (OR 3.462, 95% CI 2.798-4.285, P = 3.28 × 10^-30), URTI (OR 2.523, 95% CI 1.315-4.841, P = 0.005) and UTI (OR 2.036, 95% CI 1.585-2.616, P = 3.0 × 10^-8). However, there was no significant causal evidence for genetically predicted DrnkWk in sepsis, pneumonia, URTI or UTI. Multivariable MR analyses and sensitivity analyses showed that the above results for causal association estimations were robust.

CONCLUSION

In this MR study, we demonstrated the causal association between tobacco smoking and risk of infectious diseases. However, no evidence was found to support causality between alcohol use and the risk of infectious diseases.

Alcohol Increases Lung Angiotensin-Converting Enzyme 2 Expression and Exacerbates Severe Acute Respiratory Syndrome Coronavirus 2 Spike Protein Subunit 1-Induced Acute Lung Injury in K18-hACE2 Transgenic Mice

During the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, alcohol consumption increased markedly. Nearly one in four adults reported drinking more alcohol to cope with stress. Chronic alcohol abuse is now recognized as a factor complicating the course of acute respiratory distress syndrome and increasing mortality. To investigate the mechanisms behind this interaction, a combined acute respiratory distress syndrome and chronic alcohol abuse mouse model was developed by intratracheally instilling the subunit 1 (S1) of SARS-CoV-2 spike protein (S1SP) in K18–human angiotensin-converting enzyme 2 (ACE2) transgenic mice that express the human ACE2 receptor for SARS-CoV-2 and were kept on an ethanol diet. Seventy-two hours after S1SP instillation, mice on an ethanol diet showed a strong decrease in body weight, a dramatic increase in white blood cell content of bronchoalveolar lavage fluid, and an augmented cytokine storm, compared with S1SP-treated mice on a control diet. Histologic examination of lung tissue showed abnormal recruitment of immune cells in the alveolar space, abnormal parenchymal architecture, and worsening Ashcroft score in S1SP- and alcohol-treated animals. Along with the activation of proinflammatory biomarkers [NF-κB, STAT3, NLR family pyrin domain-containing protein 3 (NLRP3) inflammasome], lung tissue homogenates from mice on an alcohol diet showed overexpression of ACE2 compared with mice on a control diet. This model could be useful for the development of therapeutic approaches against alcohol-exacerbated coronavirus disease 2019.

Prenatal and adolescent alcohol exposure programs immunity across the lifespan: CNS-mediated regulation

For many individuals, first exposure to alcohol occurs either prenatally due to maternal drinking, or during adolescence, when alcohol consumption is most likely to be initiated. Prenatal Alcohol Exposure (PAE) and its associated Fetal Alcohol Spectrum Disorders (FASD) in humans is associated with earlier initiation of alcohol use and increased rates of Alcohol Use Disorders (AUD). Initiation of alcohol use and misuse in early adolescence correlates highly with later AUD diagnosis as well. Thus, PAE and adolescent binge drinking set the stage for long-term health consequences due to adverse effects of alcohol on subsequent immune function, effects that may persist across the lifespan. The overarching goal of this review, therefore, is to determine the extent to which early developmental exposure to alcohol produces long-lasting, and potentially life-long, changes in immunological function. Alcohol affects the whole body, yet most studies are narrowly focused on individual features of immune function, largely ignoring the systems-level interactions required for effective host defense. We therefore emphasize the crucial role of the Central Nervous System (CNS) in orchestrating host defense processes. We argue that alcohol-mediated disruption of host immunity can occur through both (a) direct action of ethanol on neuroimmune processes, that subsequently disrupt peripheral immune function (top down); and (b) indirect action of ethanol on peripheral immune organs/cells, which in turn elicit consequent changes in CNS neuroimmune function (bottom up). Recognizing that alcohol consumption across the entire body, we argue in favor of integrative, whole-organism approaches toward understanding alcohol effects on immune function, and highlight the need for more work specifically examining long-lasting effects of early developmental exposure to alcohol (prenatal and adolescent periods) on host immunity.

Robert's Intragastric Alcohol-Induced Gastric Lesion Model as an Escalated General Peripheral and Central Syndrome, Counteracted by the Stable Gastric Pentadecapeptide BPC 157

We redefined Robert's prototypical cytoprotection model, namely the intragastric administration of 96% alcohol in order to generate a general peripheral and central syndrome similar to that which occurs when major central or peripheral veins are occluded in animal models. With this redefinition, we used Robert's model to examine the cytoprotective effects of the stable gastric pentadecapeptide BPC 157. The intragastric administration of alcohol induced gastric lesions, intracranial (superior sagittal sinus) hypertension, severe brain swelling and lesions, portal and vena caval hypertension, aortal hypotension, severe thrombosis, inferior vena cava and superior mesenteric vein congestion, azygos vein failure (as a failed collateral pathway), electrocardiogram disturbances, and heart, lung, liver and kidney lesions. The use of BPC 157 therapy (10 µg/kg or 10 ng/kg given intraperitoneally 1 min after alcohol) counteracted these deficits rapidly. Specifically, BPC 157 reversed brain swelling and superior mesenteric vein and inferior vena caval congestion, and helped the azygos vein to recover, which improved the collateral blood flow pathway. Microscopically, BPC 157 counteracted brain (i.e., intracerebral hemorrhage with degenerative changes of cerebral and cerebellar neurons), heart (acute subendocardial infarct), lung (parenchymal hemorrhage), liver (congestion), kidney (congestion) and gastrointestinal (epithelium loss, hemorrhagic gastritis) lesions. In addition, this may have taken place along with the activation of specific molecular pathways. In conclusion, these findings clarify and extend the theory of cytoprotection, offer an approach to its practical application, and establish BPC 157 as a prospective cytoprotective treatment.

Acute respiratory distress syndrome: A study of autopsy findings

Context:

In this autopsy study, the various morphological patterns of acute respiratory distress syndrome (ARDS) have been analyzed and compared along with their etiopathogenesis.

Aims:

We aimed to study the prevalence and clinicopathological correlation of ARDS based on age, gender, hospital stay, symptoms, clinical diagnosis, gross, and microscopy findings.

Subjects and Methods:

Total 130 cases of ARDS were studied over a period of 5 years. Age, gender, hospital stay duration, symptoms, clinical diagnosis, gross and microscopic lung finding, clinicopathological correlation, and cause of death were documented and analyzed. Special stains were done whenever required.

Statistical Analysis:

This is an observational study, and simple statistics such as mean, median, and standard deviation have been used for continuous variables.

Results:

The prevalence of ARDS among the adult autopsy was 6.05%. Majority of the cases were in the age group of 18–30 years (36.9%), with a male: female ratio of 1.7:1. Chief complaints were fever (71%), breathlessness (54.6%), and chills (43.8%). The main clinical diagnoses were ARDS (41.6%), sepsis (28.3%), acute febrile illness (17%), and lower respiratory tract infection (12.5%). Most of the patients had a hospital stay of <1 day. Associated conditions mostly included chronic alcoholism (16.1%), pregnancy (16.1%), and chronic smoking (10.7%). Major findings on gross examination were intrapulmonary hemorrhage (38.5%), ARDS (33%), pulmonary edema (13%), and pneumonia (15.3%). On microscopy, major findings were hyaline membrane (84.6%), intrapulmonary hemorrhage (76.1%), pulmonary edema (75.3%), organizing fibrin (55.3%), and bronchopneumonia (36.2%).

Conclusion:

Infections were one of the major predisposing causes of ARDS. Due to the short interval, the underlying cause for ARDS often goes undiagnosed.

Lifestyle factors in the prevention of COVID-19

Confinement to the home and psychological distress due to the coronavirus disease 2019 (COVID-19) pandemic may lead to harmful health behaviors, such as overeating, sedentary behavior with reduced physical activity, elevated alcohol and tobacco use and increased screen time causing impaired sleep. All of these behaviors are associated with non-communicable diseases and can interfere with immunity. While no foods, single nutrients or dietary supplements are capable of preventing infection with COVID-19, a balanced diet containing sufficient amounts of macronutrients and diverse micronutrients is a prerequisite of an optimally functioning immune system. High-energy "Western" diets and obesity are major risk factors for a more severe course of COVID-19. Alcohol use and tobacco also have detrimental effects on the immune system. Therefore, population-wide body weight control, reduction of smoking rates and limitation of alcohol consumption are important preventive measures. Furthermore, sufficient restorative sleep is needed for adequate immune functioning. Appropriate lifestyle changes in regard to nutrition, exercise, sleep, smoking and alcohol intake may help shift the population distribution of infection risk and aid in preventing severe COVID-19 disease. Large-scale surveys should explore the effects of lifestyle changes, and the provision of reliable lifestyle information and effective interventions to individuals and communities during the pandemic is a pressing need.

Chronic + binge alcohol exposure promotes inflammation and alters airway mechanics in the lung

INTRODUCTION

Alcohol use disorders are major risk factors for the development of and susceptibility to acute respiratory distress syndrome. Although these risks of alcohol consumption on the lung are well described, mechanisms by which alcohol abuse promotes acute lung injury are poorly understood. These gaps in our understanding are due, at least in part, to limitations of animal models to recapitulate human alcohol consumption. Recently, a new model of chronic plus binge alcohol exposure was developed that is hypothesized to better model drinking patterns of individuals with alcohol use disorders. Specifically, this paradigm models chronic consumption coupled with periodic bouts of heavy drinking. The impacts of this alcohol-exposure regimen on the lung are uncharacterized. Therefore, the goal of this study was to examine lung injury and inflammation in a well-characterized experimental model of chronic + binge alcohol exposure.

METHODS

10-week-old male C57Bl6/J mice were administered ethanol-containing (or isocaloric control) liquid diet for 10 days, followed by a single ethanol gavage (5 g/kg). Lung inflammation and pulmonary function were assessed.

RESULTS

Ten days of ethanol-containing liquid diet alone (chronic) did not detectably affect any variables measured. However, ethanol diet plus gavage (chronic + binge) caused neutrophils to accumulate in the lung tissue and in the bronchoalveolar lavage fluid 24 h post-binge. This inflammatory cell recruitment was associated with airway hyper-responsiveness to inhaled methacholine, as indicated by elevated resistance, Newtonian resistance, and respiratory resistance.

CONCLUSIONS

Taken together, the novel findings reveal that ethanol alone, absent of any secondary inflammatory insult, is sufficient to produce inflammation in the lung. Although these changes were relatively mild, they were associated with functional changes in the central airways. This animal model may be useful in the future for identifying mechanisms by which alcohol abuse sensitizes at-risk individuals to lung injury.

Dose-dependent effects of chronic alcohol drinking on peripheral immune responses

It is well established that chronic heavy alcohol drinking (CHD) results in significant organ damage, increased susceptibility to infections, and poor outcomes following injury. In contrast, chronic moderate drinking (CMD) has been associated with improved cardiovascular health and immunity. These differential outcomes have been linked to alterations in both innate and adaptive branches of the immune system; however, the mechanisms remain poorly understood. To address this question, we determined the impact of chronic drinking on the transcriptional and functional responses of peripheral blood mononuclear cells (PBMC) collected from male rhesus macaques classified as CMD or CHD after 12 months of voluntary ethanol self-administration. Our analysis suggests that chronic alcohol drinking, regardless of dose alters resting transcriptomes of PBMC, with the largest impact seen in innate immune cells. These transcriptional changes are partially explained by alterations in microRNA profiles. Additionally, chronic alcohol drinking is associated with a dose dependent heightened inflammatory profiled at resting and following LPS stimulation. Moreover, we observed a dose-dependent shift in the kinetics of transcriptional responses to LPS. These findings may explain the dichotomy in clinical and immunological outcomes observed with moderate versus heavy alcohol drinking.

Risk factors and outcomes of acute respiratory distress syndrome in critically ill patients with cirrhosis

AIM

Prior randomized controlled trials of acute respiratory distress syndrome (ARDS) excluded critically ill patients with cirrhosis. Data regarding risk factors for ARDS development and outcomes from ARDS in patients with cirrhosis are scarce. We sought to characterize outcomes from ARDS in patients with cirrhosis.

METHODS

An observational cohort of patients with cirrhosis admitted to an intensive care unit at a high-volume liver transplant center between 1 January 2012 and 31 December 2014 were reviewed. ARDS cases were identified according to the Berlin definition. Potential risk factors were examined in multivariable logistic regression analysis for ARDS development. Outcomes including in-hospital mortality were compared between ARDS and non-ARDS patients.

RESULTS

A total of 559 patients met the inclusion criteria and 45 (8.1%) developed ARDS. Differences between ARDS and non-ARDS patients included sepsis, Model for End-Stage Liver Disease - Sodium score, and Sequential Organ Failure Assessment score. In-hospital mortality was higher in cirrhotic patients with ARDS compared with those without ARDS (82.2% vs. 27.6%, P < 0.001). In multivariable analysis, acute-on-chronic liver failure (OR 8.69, 95% CI 2.28-33.18, P < 0.01) and shock on intensive care unit admission (OR 3.13, 95% CI 1.57-6.24, P = 0.001) were associated with ARDS development, whereas etiology of cirrhosis or alcohol use were not.

CONCLUSIONS

Acute-on-chronic liver failure and shock on intensive care unit admission were risk factors for ARDS development, whereas etiology of cirrhosis and alcohol were not. Mortality from ARDS was markedly increased in patients with cirrhosis. Early recognition and treatment for infection might be important for improving the high mortality in this group of patients.

The Effect of Alcohol Consumption on the Risk of ARDS: A Systematic Review and Meta-Analysis

BACKGROUND

To conduct a systematic review and meta-analysis evaluating the association between alcohol consumption and the risk of ARDS in adults.

METHODS

Medline, EMBASE and Web of Science were searched to identify observational studies evaluating the association between prior alcohol intake and the occurrence of ARDS among adults, published between 1985 and 2015 and with no language restriction. Reference lists were also screened. Demographic baseline data were extracted independently by two reviewers and random-effects meta-analyses were used to estimate pooled effect sizes with 95% confidence intervals. Subgroup analyses were used to explore heterogeneity.

RESULTS

Seventeen observational studies (177,674 people) met the inclusion criteria. Meta-analysis of 13 studies showed that any measure of high relative to low alcohol consumption was associated with a significantly increased risk of ARDS (OR, 1.89; 95% CI, 1.45-2.48; I2 = 48%; 13 studies); no evidence of publication bias was seen (P = .150). Sensitivity analyses indicated that this association was attributable primarily to an effect of a history of alcohol abuse (OR, 1.90; 95% CI, 1.40-2.60; 10 studies). Also, subgroup analyses identified that heterogeneity was explained by predisposing condition (trauma, sepsis/septic shock, pneumonia; P = .003).

CONCLUSIONS

Chronic high alcohol consumption significantly increases the risk of ARDS. This finding suggests that patients admitted to hospital should be screened for chronic alcohol use.

Increased incidence of allergic rhinitis, bronchitis and asthma, in children living near a petrochemical complex with SO2 pollution

This study aims to investigate incidence of allergic rhinitis, bronchitis and asthma, in children living near a petrochemical complex with SO₂ pollution obtained by air monitoring stations. A total of 587 children aged 11 to 14 were recruited and classified into high and low exposure groups based on a radius of 10km from the complex. To study the influence of health on children since the operation of complex in 1999 and observe the difference of these diseases' short-term and long-term impact, we obtained the incidence rates of allergic rhinitis (ICD-9: 477), bronchitis (490-491) and asthma (493) from the Taiwan Health Insurance Database for three periods: 1999-2002, 1999-2006, and 1999-2010. Since 2001, the mean and 99th percentile of SO₂ concentrations in the high exposure area have been significantly higher than those in low exposure area. There were significant differences between the high and low exposure groups in the percentage of smoking, alcohol consumption, passive smoking exposure and incense burning habits. The incidence rates of three intervals were 26.9%, 35.7%, 41.7%; 8.3%, 8.8%, 10.2%; 18.5%, 25.0%, 26.9% for allergic rhinitis, bronchitis and asthma in high exposure group. Significant differences were found between groups for allergic rhinitis in all periods, bronchitis in the first two periods, and asthma in the first period using Student's t-test. After we adjusted age, gender, group, living near roads, incense burning and passive smoking exposure, the hazard ratios between exposure groups were 3.05, 2.74, and 1.93 for allergic rhinitis with significant difference in three periods, and 2.53, 1.92 and 1.72 for bronchitis with significant difference in first period and 1.60, 1.28 and 1.29 for asthma with significant difference in first period by Cox regression. The higher incidence of allergic rhinitis was related to boys and living near roads and the higher incidence of asthma was also related to younger children, boys, and passive smoking exposure.

The relative balance of GM-CSF and TGF-β1 regulates lung epithelial barrier function

Lung barrier dysfunction is a cardinal feature of the acute respiratory distress syndrome (ARDS). Alcohol abuse, which increases the risk of ARDS two- to fourfold, induces transforming growth factor (TGF)-β1, which increases epithelial permeability and impairs granulocyte/macrophage colony-stimulating factor (GM-CSF)-dependent barrier integrity in experimental models. We hypothesized that the relative balance of GM-CSF and TGF-β1 signaling regulates lung epithelial barrier function. GM-CSF and TGF-β1 were tested separately and simultaneously for their effects on lung epithelial cell barrier function in vitro. TGF-β1 alone caused an ∼ 25% decrease in transepithelial resistance (TER), increased paracellular flux, and was associated with projections perpendicular to tight junctions ("spikes") containing claudin-18 that colocalized with F-actin. In contrast, GM-CSF treatment induced an ∼ 20% increase in TER, decreased paracellular flux, and showed decreased colocalization of spike-associated claudin-18 with F-actin. When simultaneously administered to lung epithelial cells, GM-CSF antagonized the effects of TGF-β1 on epithelial barrier function in cultured cells. Given this, GM-CSF and TGF-β1 levels were measured in bronchoalveolar lavage (BAL) fluid from patients with ventilator-associated pneumonia and correlated with markers for pulmonary edema and patient outcome. In patient BAL fluid, protein markers of lung barrier dysfunction, serum α2-macroglobulin, and IgM levels were increased at lower ratios of GM-CSF/TGF-β1. Critically, patients who survived had significantly higher GM-CSF/TGF-β1 ratios than nonsurviving patients. This study provides experimental and clinical evidence that the relative balance between GM-CSF and TGF-β1 signaling is a key regulator of lung epithelial barrier function. The GM-CSF/TGF-β1 ratio in BAL fluid may provide a concentration-independent biomarker that can predict patient outcomes in ARDS.

Donor smoking is associated with pulmonary edema, inflammation and epithelial dysfunction in ex vivo human donor lungs

Although recipients of donor lungs from smokers have worse clinical outcomes, the underlying mechanisms are unknown. We tested the association between donor smoking and the degree of pulmonary edema (as estimated by lung weight), the rate of alveolar fluid clearance (AFC; measured by airspace instillation of 5% albumin) and biomarkers of lung epithelial injury and inflammation (bronchoalveolar lavage [BAL] surfactant protein-D (SP-D) and IL-8) in ex vivo lungs recovered from 298 organ donors. The extent of pulmonary edema was higher in current smokers (n = 127) compared to nonsmokers (median 408 g, interquartile range [IQR] 364-500 vs. 385 g, IQR 340-460, p = 0.009). Oxygenation at study enrollment was worse in current smokers versus nonsmokers (median PaO2 /FiO2 214 mm Hg, IQR 126-323 vs. 266 mm Hg, IQR 154-370, p = 0.02). Current smokers with the highest exposure (≥20 pack years) had significantly lower rates of AFC, suggesting that the effects of cigarette smoke on alveolar epithelial fluid transport function may be dose related. BAL IL-8 was significantly higher in smokers while SP-D was lower. These findings indicate that chronic exposure to cigarette smoke has important effects on inflammation, gas exchange, lung epithelial function and lung fluid balance in the organ donor that could influence lung function in the lung transplant recipient.

Thrombocytopenia in adult patients with sepsis: incidence, risk factors, and its association with clinical outcome

Background

Sepsis is a major risk factor for the development of thrombocytopenia, but few studies have specifically evaluated prognostic importance of thrombocytopenia in patients with sepsis. We investigated the incidence, risk factors, and prognostic importance of thrombocytopenia in adult patients admitted to the intensive care unit (ICU) with sepsis.

Methods

A retrospective analysis of patients admitted with severe sepsis/septic shock from December 2007 to January 2009 to a 24-bed medical ICU was done.

Results

A total of 304 patients were included in the study. The patients' mean (±SD) age was 68.8 (±15.8) years. The majority (93.7%) had septic shock, and pneumonia was the most common infection (38.8%). Thrombocytopenia developed in 145 patients (47.6%): 77 (25.3%) at ICU admission and 68 (22.3%) during their hospital course. The median (IQR) duration of thrombocytopenia was 4.4 (1.9–6.9) days. Patients who developed thrombocytopenia had more episodes of major bleeding (14.4% vs. 3.7%, P < 0.01) and received more transfusions. Patients with thrombocytopenia had a higher incidence of acute kidney injury (44.1% vs. 29.5%, P < 0.01), prolonged vasopressor support (median (IQR): 37 (17–76) vs. 23 (13–46) h, P < 0.01), and longer ICU stay (median (IQR): 3.1 (1.6–7.8) vs. 2.1 (1.2–4.4) days, P < 0.01). The 28-day mortality was similar between patients with and without thrombocytopenia (32.4% vs. 24.5%, P = 0.12). However, while 15 of 86 patients (17.4%) who resolved their thrombocytopenia died, 32 of 59 patients (54.2%) whose thrombocytopenia did not resolve died (P < 0.01). The association between non-resolution of thrombocytopenia and mortality remained significant after adjusting for age, APACHE III score and compliance with a sepsis resuscitation bundle (P < 0.01).

Conclusions

Thrombocytopenia is common in patients who are admitted to the ICU with severe sepsis and septic shock. Patients with thrombocytopenia had more episodes of major bleeding, increased incidence of acute kidney injury, and prolonged ICU stay. Non-resolution of thrombocytopenia, but not thrombocytopenia itself, was associated with increased 28-day mortality.

Alcoholism causes alveolar macrophage zinc deficiency and immune dysfunction

RATIONALE

Alcohol use disorders cause oxidative stress in the lower airways and increase susceptibility to pneumonia and lung injury. Currently, no therapeutic options exist to mitigate the pulmonary consequences of alcoholism.

OBJECTIVES

We recently determined in an animal model that alcohol ingestion impairs pulmonary zinc metabolism and causes alveolar macrophage immune dysfunction. The objective of this research is to determine the effects of alcoholism on zinc bioavailability and alveolar macrophage function in human subjects.

METHODS

We recruited otherwise healthy alcoholics (n = 17) and matched control subjects (n = 17) who underwent bronchoscopy for isolation of alveolar macrophages, which were analyzed for intracellular zinc, phagocytic function, and surface expression of granulocyte-macrophage colony-stimulating factor receptor; all three of these indices are decreased in experimental models.

MEASUREMENTS AND MAIN RESULTS

Alcoholic subjects had normal serum zinc, but significantly decreased alveolar macrophage intracellular zinc levels (adjusted means [SE], 718 [41] vs. 948 [25] RFU/cell; P < 0.0001); bacterial phagocytosis (adjusted means [SE], 1,027 [48] vs. 1,509 [76] RFU/cell; P < 0.0001); and expression of granulocyte-macrophage colony-stimulating factor receptor β subunit (adjusted means [SE], 1,471 [42] vs. 2,114 [35] RFU/cell; P < 0.0001]. Treating alveolar macrophages with zinc acetate and glutathione in vitro increased intracellular zinc levels and improved their phagocytic function.

CONCLUSIONS

These novel clinical findings provide evidence that alcohol abuse is associated with significant zinc deficiency and immune dysfunction within the alveolar space and suggest that dietary supplementation with zinc and glutathione precursors could enhance airway innate immunity and decrease the risk for pneumonia or lung injury in these vulnerable individuals.

Risk factors for the development of acute lung injury in patients with infectious pneumonia

INTRODUCTION

Although pneumonia has been identified as the single most common risk factor for acute lung injury (ALI), we have a limited knowledge as to why ALI develops in some patients with pneumonia and not in others. The objective of this study was to determine frequency, risk factors, and outcome of ALI in patients with infectious pneumonia.

METHODS

A retrospective cohort study of adult patients with microbiologically positive pneumonia, hospitalized at two Mayo Clinic Rochester hospitals between January 1, 2005, and December 31, 2007. In a subsequent nested case-control analysis, we evaluated the differences in prehospital and intrahospital exposures between patients with and without ALI/acute respiratory distress syndrome (ARDS) matched by specific pathogen, isolation site, gender, and closest age in a 1:1 manner.

RESULTS

The study included 596 patients; 365 (61.2%) were men. The median age was 65 (IQR, 53 to 75) years. In total, 171 patients (28.7%) were diagnosed with ALI. The occurrence of ALI was less frequent in bacterial (n = 99 of 412, 24%) compared with viral (n = 19 of 55, 35%), fungal (n = 39 of 95, 41%), and mixed isolates pneumonias (n = 14 of 34, 41%; P = 0.002). After adjusting for baseline severity of illness and comorbidities, patients in whom ALI developed had a markedly increased risk of hospital death (ORadj 9.7; 95% CI, 6.0 to 15.9). In a nested case-control study, presence of shock (OR, 8.9; 95% CI, 2.8 to 45.9), inappropriate initial antimicrobial treatment (OR, 3.2; 95% CI, 1.3 to 8.5), and transfusions (OR, 4.8; 95% CI, 1.5 to 19.6) independently predicted ALI development.

CONCLUSIONS

The development of ALI among patients hospitalized with infectious pneumonia varied among pulmonary pathogens and was associated with increased mortality. Inappropriate initial antimicrobial treatment and transfusion predict the development of ALI independent of pathogen.

Epidemiology of ARDS and ALI

Acute respiratory distress syndrome (ARDS) and acute lung injury (ALI) are distinctly modern clinical entities. Recent epidemiologic research has taken advantage of large cohorts in efforts to better describe these highly lethal syndromes with a focus on differentiation of clinically meaningful subtypes and early prediction in an effort to improve treatment and prevention. This article identifies the most significant studies and systematic reviews of recent years, defining the incidence, mortality, risk and prognostic factors, and etiologic classes of ARDS/ALI.

Perioperative management of patients with alcohol, tobacco and drug dependency

PURPOSE OF REVIEW

One in five patients in the perioperative setting has a alcohol use disorder (AUD), one in three patients has a nicotine use disorder (NUD) and one in 10 patients has a drug use disorder (DUD) with a high risk of dependency. Patients with dependencies challenge physicians with various complications within the perioperative setting.

RECENT FINDINGS

Adequate treatment of alcohol, nicotine and drug dependency during the perioperative and intraoperative course requires established screening tools in order to evaluate patients' susceptibility to developing complications. Particularly in these patients, secondary prevention and early treatment is warranted.

SUMMARY

Alcohol, nicotine and drug dependency are very treatable. Numerous effective therapeutic options are available and should be offered to patients. Intensive care treatment can be shortened or even avoided by initiating preventive measures. A multimodal approach includes implementation of screening tools, motivational interviewing, preoperative abstinence, individual anaesthesiological treatment, stress reduction preventing delirium and postoperative infection, prevention and treatment of withdrawal syndrome, replacement therapies and provision of preoperative or postoperative detoxification. The implementation rate is very low and urgently requires strategies for improvement.

Ventilation with lower tidal volumes as compared with conventional tidal volumes for patients without acute lung injury: a preventive randomized controlled trial

Introduction

Recent cohort studies have identified the use of large tidal volumes as a major risk factor for development of lung injury in mechanically ventilated patients without acute lung injury (ALI). We compared the effect of conventional with lower tidal volumes on pulmonary inflammation and development of lung injury in critically ill patients without ALI at the onset of mechanical ventilation.

Methods

We performed a randomized controlled nonblinded preventive trial comparing mechanical ventilation with tidal volumes of 10 ml versus 6 ml per kilogram of predicted body weight in critically ill patients without ALI at the onset of mechanical ventilation. The primary end point was cytokine levels in bronchoalveolar lavage fluid and plasma during mechanical ventilation. The secondary end point was the development of lung injury, as determined by consensus criteria for ALI, duration of mechanical ventilation, and mortality.

Results

One hundred fifty patients (74 conventional versus 76 lower tidal volume) were enrolled and analyzed. No differences were observed in lavage fluid cytokine levels at baseline between the randomization groups. Plasma interleukin-6 (IL-6) levels decreased significantly more strongly in the lower-tidal-volume group ((from 51 (20 to 182) ng/ml to 11 (5 to 20) ng/ml versus 50 (21 to 122) ng/ml to 21 (20 to 77) ng/ml; P = 0.01)). The trial was stopped prematurely for safety reasons because the development of lung injury was higher in the conventional tidal-volume group as compared with the lower tidal-volume group (13.5% versus 2.6%; P = 0.01). Univariate analysis showed statistical relations between baseline lung-injury score, randomization group, level of positive end-expiratory pressure (PEEP), the number of transfused blood products, the presence of a risk factor for ALI, and baseline IL-6 lavage fluid levels and the development of lung injury. Multivariate analysis revealed the randomization group and the level of PEEP as independent predictors of the development of lung injury.

Conclusions

Mechanical ventilation with conventional tidal volumes is associated with sustained cytokine production, as measured in plasma. Our data suggest that mechanical ventilation with conventional tidal volumes contributes to the development of lung injury in patients without ALI at the onset of mechanical ventilation.

Trial registration

ISRCTN82533884