Laparoscopy is associated with decreased all-cause mortality in patients undergoing emergency general surgery procedures in a regional health system.

BACKGROUND: The aim of this study was to evaluate the use of laparoscopic surgery for common emergency general surgery (EGS) procedures within an integrated Acute Care Surgery (ACS) network. We hypothesized that laparoscopy would be associated with improved outcomes. METHODS: Our integrated health care system's EGS registry created from AAST EGS ICD-9 codes was queried from January 2013 to October 2015. Procedures were grouped as laparoscopic or open. Standard descriptive and univariate tests were performed, and a multivariable logistic regression controlling for open status, age, BMI, Charlson Comorbidity Index (CCI), trauma tier, and resuscitation diagnosis was performed. Laparoscopic procedures converted to open were identified and analyzed using concurrent procedure billing codes across episodes of care. RESULTS: Of 60,604 EGS patients identified over the 33-month period, 7280 (12.0%) had an operation and 6914 (11.4%) included AAST-defined EGS procedures. There were 4813 (69.6%) surgeries performed laparoscopically. Patients undergoing a laparoscopic procedure tended to be younger (45.7 ± 18.0 years vs. 57.2 ± 17.6, p < 0.001) with similar BMI (29.7 ± 9.0 kg/m2 vs. 28.8 ± 8.3, p < 0.001). Patients in the laparoscopic group had lower mean CCI score (1.6 ± 2.3 vs. 3.4 ± 3.2, p ≤ 0.0001). On multivariable analysis, open surgery had the highest association with inpatient mortality (OR 8.67, 4.23-17.75, p < 0.0001) and at all time points (30-, 90-day, 1-, 3-year). At all time points, conversion to open was found to be a statistically significant protective factor. CONCLUSION: Use of laparoscopy in EGS is common and associated with a decreased risk of all-cause mortality at all time points compared to open procedures. Conversion to open was protective at all time points compared to open procedures.

Balanced Crystalloids versus Saline in Critically Ill Adults.

BACKGROUND: Both balanced crystalloids and saline are used for intravenous fluid administration in critically ill adults, but it is not known which results in better clinical outcomes. METHODS: In a pragmatic, cluster-randomized, multiple-crossover trial conducted in five intensive care units at an academic center, we assigned 15,802 adults to receive saline (0.9% sodium chloride) or balanced crystalloids (lactated Ringer's solution or Plasma-Lyte A) according to the randomization of the unit to which they were admitted. The primary outcome was a major adverse kidney event within 30 days - a composite of death from any cause, new renal-replacement therapy, or persistent renal dysfunction (defined as an elevation of the creatinine level to ≥200% of baseline) - all censored at hospital discharge or 30 days, whichever occurred first. RESULTS: Among the 7942 patients in the balanced-crystalloids group, 1139 (14.3%) had a major adverse kidney event, as compared with 1211 of 7860 patients (15.4%) in the saline group (marginal odds ratio, 0.91; 95% confidence interval [CI], 0.84 to 0.99; conditional odds ratio, 0.90; 95% CI, 0.82 to 0.99; P=0.04). In-hospital mortality at 30 days was 10.3% in the balanced-crystalloids group and 11.1% in the saline group (P=0.06). The incidence of new renal-replacement therapy was 2.5% and 2.9%, respectively (P=0.08), and the incidence of persistent renal dysfunction was 6.4% and 6.6%, respectively (P=0.60). CONCLUSIONS: Among critically ill adults, the use of balanced crystalloids for intravenous fluid administration resulted in a lower rate of the composite outcome of death from any cause, new renal-replacement therapy, or persistent renal dysfunction than the use of saline. (Funded by the Vanderbilt Institute for Clinical and Translational Research and others; SMART-MED and SMART-SURG ClinicalTrials.gov numbers, NCT02444988 and NCT02547779 .).

Readmission After Emergency General Surgery: NSQIP Review of Risk, Cause and Ideal Follow-Up.

BACKGROUND: The Emergency General Surgery (EGS) population is particularly at high risk for readmission. Currently, no system exists to predict which EGS patients are most at risk. We hypothesized that a subset of EGS patients could be identified with increased 30-day unplanned readmission. We also hypothesized that a majority of readmissions occur sooner than the conventional 2-week follow-up period. METHODS: National Surgical Quality Improvement Program (NSQIP) nonelective general surgery patients were analyzed. Multivariable logistic regression identified factors with increased odds of unplanned readmission. AAST EGS Diagnosis Categories were used to categorize postop ICD-9 codes, and the top 10 CPT codes in each group were analyzed. Readmission rate, the reason for unplanned readmission, and time to readmission were analyzed. RESULTS: A total of 383,726 patients were identified with a readmission rate of 8.1% within 30 d of their primary procedure. The top 50 CPT codes accounted for 84% of EGS readmissions. Increased readmission risk was demonstrated for underweight patients (OR = 1.15, P < 0.05). High-risk hospital characteristics were LOS >2 d, any inpatient pulmonary complications, and discharge to any facility or rehab (all P < 0.05). Surgical site infections cause nearly 25% of readmissions. Intestinal procedures are most frequently readmitted (22% of EGS readmissions), with colorectal procedures having the higher odds of readmission. Most readmissions occur <10 d after discharge. CONCLUSIONS: A high-risk subpopulation exists within EGS, and most readmissions occur sooner than a typical 2-week follow-up. Early interventions for high-risk EGS subpopulations may allow for early intervention and reduction of unnecessary healthcare utilization.

Factors Associated With Prolonged Antibiotic Use in the Setting of Suspected Pneumonia and Negative Bronchoalveolar Lavage Cultures.

Background: Diagnostic criterion for pneumonia includes clinical data and bronchoalveolar lavage cultures (BALCx) to identify pathogens. Although ~60% of BALCx are negative, there may be reluctance to discontinue antibiotics, leading to prolonged antibiotic use (PAU). Objective: The purpose of this study is to compare outcomes of subjects with negative BALCx with PAU versus without prolonged antibiotic use (nPAU). Methods: A retrospective cohort study was conducted including subjects admitted to the intensive care unit (ICU), with suspected pneumonia, and negative BALCx. Data were compared based on length of exposure to antibiotics, PAU (antibiotics >4 days) versus nPAU (antibiotics <4 days). Results: A total of 128 subjects were included, 57 in the PAU group and 71 in the nPAU group. Baseline demographics were similar between groups. Severity of illness measured by multiple organ dysfunction scores at time of bronchoalveolar lavage (BAL) collection to final result showed a statistically significant decrease in the PAU group but not in the nPAU group. No differences were found in ICU days, ventilator-free days, or mortality; however, length of stay was longer for PAU (23 vs. 17, p = .04). In the PAU group, there were fewer BALCx results of "no growth" (23% vs. 45%, p = .04), more positive gram stains (83% vs. 60%, p = .01) and more positive non-BALCx (40% vs. 14%, p = .01). In a multivariate analysis, factors associated with PAU were positive BAL gram stains (adjusted odds ratio [aOR] 3.1, p = .037) and positive non-BALCx (aOR 4.7, p = .002). Conclusion: For subjects with suspected pneumonia and negative BALCx, positive non-BALCx and positive BALCx gram stain influenced the length of exposure of antibiotics.

A Novel Immune Modulator for Patients With Necrotizing Soft Tissue Infections (NSTI): Results of a Multicenter, Phase 3 Randomized Controlled Trial of Reltecimod (AB 103).

BACKGROUND AND OBJECTIVE: Reltecimod, a CD 28 T-lymphocyte receptor mimetic, inhibits T-cell stimulation by an array of bacterial pathogens. A previous phase 2 trial demonstrated improved resolution of organ dysfunction after NSTI. We hypothesized that early administration of reltecimod would improve outcome in severe NSTI. METHODS: Randomized, double-blind, placebo-controlled trial of single dose reltecimod (0.5 mg/kg) administered within 6 hours of NSTI diagnosis at 65 of 93 study sites. Inclusion: surgical confirmation of NSTI and organ dysfunction [modified Sequential Organ Failure Assessment Score (mSOFA) score ≥3]. Primary analysis was modified Intent-to-Treat (mITT), responder analysis using a previously validated composite endpoint, necrotizing infection clinical composite endpoint, defined as: alive at day 28, ≤3 debridements, no amputation beyond first operation, and day 14 mSOFA ≤1 with ≥3 point reduction (organ dysfunction resolution). A prespecified, per protocol (PP) analysis excluded 17 patients with major protocol violations before unblinding. RESULTS: Two hundred ninety patients were enrolled, mITT (Reltecimod 142, Placebo 148): mean age 55 ±â€Š15 years, 60% male, 42.4% diabetic, 28.6% perineal infection, screening mSOFA mean 5.5 ±â€Š2.4. Twenty-eight-day mortality was 15% in both groups. mITT necrotizing infection clinical composite endpoint success was 48.6% reltecimod versus 39.9% placebo, P = 0.135 and PP was 54.3% reltecimod versus 40.3% placebo, P = 0.021. Resolution of organ dysfunction was 65.1% reltecimod versus 52.6% placebo, P = 0.041, mITT and 70.9% versus 53.4%, P = 0.005, PP. CONCLUSION: Early administration of reltecimod in severe NSTI resulted in a significant improvement in the primary composite endpoint in the PP population but not in the mITT population. Reltecimod was associated with improved resolution of organ dysfunction and hospital discharge status.

Surgery and Anesthesia Exposure Is Not a Risk Factor for Cognitive Impairment After Major Noncardiac Surgery and Critical Illness.

OBJECTIVE: The aim of this study was to determine whether surgery and anesthesia exposure is an independent risk factor for cognitive impairment after major noncardiac surgery associated with critical illness. SUMMARY OF BACKGROUND DATA: Postoperative cognitive impairment is a prevalent individual and public health problem. Data are inconclusive as to whether this impairment is attributable to surgery and anesthesia exposure versus patients' baseline factors and hospital course. METHODS: In a multicenter prospective cohort study, we enrolled ICU patients with major noncardiac surgery during hospital admission and with nonsurgical medical illness. At 3 and 12 months, we assessed survivors' global cognitive function with the Repeatable Battery for the Assessment of Neuropsychological Status and executive function with the Trail Making Test, Part B. We performed multivariable linear regression to study the independent association of surgery/anesthesia exposure with cognitive outcomes, adjusting initially for baseline covariates and subsequently for in-hospital covariates. RESULTS: We enrolled 1040 patients, 402 (39%) with surgery/anesthesia exposure. Median global cognition scores were similar in patients with surgery/anesthesia exposure compared with those without exposure at 3 months (79 vs 80) and 12 months (82 vs 82). Median executive function scores were also similar at 3 months (41 vs 40) and 12 months (43 vs 42). Surgery/anesthesia exposure was not associated with worse global cognition or executive function at 3 or 12 months in models incorporating baseline or in-hospital covariates (P > 0.2). Higher baseline education level was associated with better global cognition at 3 and 12 months (P < 0.001), and longer in-hospital delirium duration was associated with worse global cognition (P < 0.02) and executive function (P < 0.01) at 3 and 12 months. CONCLUSIONS: Cognitive impairment after major noncardiac surgery and critical illness is not associated with the surgery and anesthesia exposure but is predicted by baseline education level and in-hospital delirium.

Long-Term Ozone Exposure Increases the Risk of Developing the Acute Respiratory Distress Syndrome.

RATIONALE: The contribution of air pollution to the risk of acute respiratory distress syndrome (ARDS) is unknown. METHODS: We studied 1,558 critically ill patients enrolled in a prospective observational study at a tertiary medical center who lived less than 50 km from an air quality monitor and had an ARDS risk factor. Pollutant exposures (ozone, NO2, SO2, particulate matter < 2.5 µm, particulate matter < 10 µm) were assessed by weighted average of daily levels from the closest monitors for the prior 3 years. Associations between pollutant exposure and ARDS risk were evaluated by logistic regression controlling for age, race, sex, smoking, alcohol, insurance status, rural versus urban residence, distance to study hospital, and Acute Physiology and Chronic Health Evaluation II. MEASUREMENTS AND MAIN RESULTS: The incidence of ARDS increased with increasing ozone exposure: 28% in the lowest exposure quartile versus 32, 40, and 42% in the second, third, and fourth quartiles (P < 0.001). In a logistic regression model controlling for potential confounders, ozone exposure was associated with risk of ARDS in the entire cohort (odds ratio, 1.58 [95% confidence interval, 1.27-1.96]) and more strongly associated in the subgroup with trauma as their ARDS risk factor (odds ratio, 2.26 [95% confidence interval, 1.46-3.50]). There was a strong interaction between ozone exposure and current smoking status (P = 0.007). NO2 exposure was also associated with ARDS but not independently of ozone exposure. SO2, particulate matter less than 2.5 µm, and particulate matter less than 10 µm were not associated with ARDS. CONCLUSIONS: Long-term ozone exposure is associated with development of ARDS in at-risk critically ill patients, particularly in trauma patients and current smokers. Ozone exposure may represent a previously unrecognized environmental risk factor for ARDS.

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.

Efficacy and Safety of Glutamine-supplemented Parenteral Nutrition in Surgical ICU Patients: An American Multicenter Randomized Controlled Trial.

OBJECTIVE: To determine whether glutamine (GLN)-supplemented parenteral nutrition (PN) improves clinical outcomes in surgical intensive care unit (SICU) patients. SUMMARY BACKGROUND DATA: GLN requirements may increase with critical illness. GLN-supplemented PN may improve clinical outcomes in SICU patients. METHODS: A parallel-group, multicenter, double-blind, randomized, controlled clinical trial in 150 adults after gastrointestinal, vascular, or cardiac surgery requiring PN and SICU care. Patients were without significant renal or hepatic failure or shock at entry. All received isonitrogenous, isocaloric PN [1.5 g/kg/d amino acids (AAs) and energy at 1.3× estimated basal energy expenditure]. Controls (n = 75) received standard GLN-free PN (STD-PN); the GLN group (n = 75) received PN containing alanyl-GLN dipeptide (0.5 g/kg/d), proportionally replacing AA in PN (GLN-PN). Enteral nutrition (EN) was advanced and PN weaned as indicated. Hospital mortality and infections were primary endpoints. RESULTS: Baseline characteristics, days on study PN and daily macronutrient intakes via PN and EN, were similar between groups. There were 11 hospital deaths (14.7%) in the GLN-PN group and 13 deaths in the STD-PN group (17.3%; difference, -2.6%; 95% confidence interval, -14.6% to 9.3%; P = 0.66). The 6-month cumulative mortality was 31.4% in the GLN-PN group and 29.7% in the STD-PN group (P = 0.88). Incident bloodstream infection rate was 9.6 and 8.4 per 1000 hospital days in the GLN-PN and STD-PN groups, respectively (P = 0.73). Other clinical outcomes and adverse events were similar. CONCLUSIONS: PN supplemented with GLN dipeptide was safe, but did not alter clinical outcomes among SICU patients.

Prehospital aspirin use is associated with reduced risk of acute respiratory distress syndrome in critically ill patients: a propensity-adjusted analysis.

OBJECTIVES: Platelet activation plays an active role in the pathogenesis of acute respiratory distress syndrome. In our prior study of 575 patients at high risk for acute respiratory distress syndrome, concurrent statin and aspirin use was associated with reduced acute respiratory distress syndrome. However, the largest study (n = 3,855) to date found no significant benefit of prehospital aspirin in a lower-risk population when adjusted for the propensity for aspirin use. We aimed to determine whether prehospital aspirin use is associated with decreased acute respiratory distress syndrome in patients at high risk for acute respiratory distress syndrome after adjusting for the propensity to receive aspirin. DESIGN: Secondary analysis of patients enrolled prospectively in the Validating Acute Lung Injury Markers for Diagnosis study. PATIENTS: A total of 1,149 critically ill patients (≥40 years old) admitted to the medical or surgical ICUs of an academic tertiary care hospital including 575 previously reported patients as well as additional patients who were enrolled after completion of the prior statin and aspirin study. INTERVENTION: None. MEASUREMENTS AND RESULTS: Of 1,149 patients, 368 (32%) developed acute respiratory distress syndrome during the first 4 ICU days and 287 (25%) patients had prehospital aspirin use. Patients with prehospital aspirin had significantly lower prevalence of acute respiratory distress syndrome (27% vs 34%; p=0.034). In a multivariable, propensity-adjusted analysis including age, gender, race, sepsis, and Acute Physiology and Chronic Health Evaluation score II, prehospital aspirin use was associated with a decreased risk of acute respiratory distress syndrome (odds ratio, 0.66; 95% CI, 0.46-0.94) in the entire cohort and in a subgroup of 725 patients with sepsis (odds ratio, 0.60; 95% CI, 0.41-0.90). CONCLUSIONS: In this selected cohort of critically ill patients, prehospital aspirin use was independently associated with a decreased risk of acute respiratory distress syndrome even after adjusting for the propensity of prehospital aspirin use. These findings support the need for prospective clinical trials to determine whether aspirin may be beneficial for the prevention of clinical acute respiratory distress syndrome.

Atrial Fibrillation Is an Independent Predictor of Mortality in Critically Ill Patients.

OBJECTIVES: Atrial fibrillation has been associated with increased mortality in critically ill patients. We sought to determine whether atrial fibrillation in the ICU is an independent risk factor for death. A secondary objective was to determine if patients with new-onset atrial fibrillation have different risk factors or outcomes compared with patients with a previous history of atrial fibrillation. DESIGN: Prospective observational cohort study. SETTING: Medical and general surgical ICUs in a tertiary academic medical center. PATIENTS: One thousand seven hundred seventy critically ill patients requiring at least 2 days in the ICU. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Demographics, medical history, development of atrial fibrillation, fluid balance, echocardiographic findings, medication administration, and hospital mortality were collected during the first 4 days of ICU admission. Atrial fibrillation occurred in 236 patients (13%) (Any AF). Of these, 123 patients (7%) had no prior atrial fibrillation (New-onset AF) while the remaining 113 (6%) had recurrent atrial fibrillation (Recurrent AF). Any AF was associated with male gender, Caucasian race, increased age, cardiac disease, organ failures, and disease severity. Patients with Any AF had increased mortality compared with those without atrial fibrillation (31% vs 17%; p < 0.001), and Any AF was independently associated with death (odds ratio, 1.62; 95% CI, 1.14-2.29; p = 0.007) in multivariable analysis controlling for severity of illness and other confounders. The association of atrial fibrillation with death was magnified in patients without sepsis (odds ratio, 2.92; 95% CI, 1.52-5.60; p = 0.001). Treatment for atrial fibrillation had no effect on hospital mortality. New-onset AF and Recurrent AF were each associated with increased mortality. New-onset AF, but not Recurrent AF, was associated with increased diastolic dysfunction and vasopressor use and a greater cumulative positive fluid balance. CONCLUSIONS: Atrial fibrillation in critical illness, whether new-onset or recurrent, is independently associated with increased hospital mortality, especially in patients without sepsis.

A Randomized Dose-Escalation Study of the Safety and Anti-Inflammatory Activity of the p38 Mitogen-Activated Protein Kinase Inhibitor Dilmapimod in Severe Trauma Subjects at Risk for Acute Respiratory Distress Syndrome.

OBJECTIVES: There are no current pharmacological therapies for the prevention or treatment of acute respiratory distress syndrome. Early dysregulated inflammation likely plays a role in acute respiratory distress syndrome development and possibly acute respiratory distress syndrome outcomes. p38 mitogen-activated protein kinase is central to the regulation of multiple inflammatory mediators implicated in acute organ dysfunction and is the target for a novel class of cytokine-suppressive anti-inflammatory drugs. In preclinical models, p38 inhibitors reduce lung injury following pancreatitis and burn injury. DESIGN: We conducted a phase IIa, randomized, double-blind, placebo-controlled, parallel-group study to evaluate the safety and tolerability of dilmapimod, a novel p38 mitogen-activated protein kinase inhibitor, in patients at risk for developing acute respiratory distress syndrome admitted with an Injury Severity Score more than 16, excluding head trauma. Enrolled patients received 4- or 24-hour IV dilmapimod infusions at different doses or placebo, daily for 3 days, in four separate cohorts. SETTING: Multicenter randomized clinical trial of large, academic trauma centers. MEASUREMENTS AND MAIN RESULTS: Seventy-seven patients were enrolled. Although adverse events were common in this critically ill population, dilmapimod was well tolerated, with no clinically relevant safety findings. Pharmacokinetic models indicated that the higher dose of 10 mg given as continuous infusion over 24 hours had the most favorable plasma concentration profile. Likewise, measures of soluble inflammatory markers including interleukin-6, C-reactive peptide, interleukin-8, and soluble tumor necrosis factor receptor 1 were most different between this dosing arm and placebo. Although the study was not specifically designed with acute respiratory distress syndrome as an outcome, the number of patients who developed acute respiratory distress syndrome was small (2/77). CONCLUSIONS: The novel p38 mitogen-activated protein kinase inhibitor dilmapimod appears well tolerated and may merit further evaluation for prevention of acute respiratory distress syndrome and other organ injury in larger clinical trials. Furthermore, results of this early-phase trial may aid in design of future studies aimed at prevention of acute respiratory distress syndrome and other organ injury.

Cigarette Smoke Exposure and the Acute Respiratory Distress Syndrome.

OBJECTIVE: The association between cigarette smoke exposure and the acute respiratory distress syndrome in patients with the most common acute respiratory distress syndrome risk factors of sepsis, pneumonia, and aspiration has not been well studied. The goal of this study was to test the association between biomarker-confirmed cigarette smoking and acute respiratory distress syndrome in a diverse cohort. DESIGN: Prospective cohort. SETTING: Tertiary care center. PATIENTS: Four hundred twenty-six critically ill patients with acute respiratory distress syndrome risk factors (excluding trauma and transfusion) INTERVENTIONS: : None. MEASUREMENTS AND MAIN RESULTS: We obtained smoking histories and measured urine 4-(methylnitrosamino)-1-(3-pyridyl)-1- butanol (a biomarker of cigarette smoke exposure) on urine samples obtained at the time of study enrollment. The association between cigarette smoke exposure and acute respiratory distress syndrome differed based on acute respiratory distress syndrome risk factor (p < 0.02 for interaction). In patients with nonpulmonary sepsis as the primary acute respiratory distress syndrome risk factor (n = 212), 39% of those with acute respiratory distress syndrome were current smokers by history compared with 22% of those without acute respiratory distress syndrome (odds ratio, 2.28; 95% CI, 1.24-4.19; p = 0.008). Likewise, cigarette smoke exposure as measured by urine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol was significantly associated with acute respiratory distress syndrome in this group. The increased risk of acute respiratory distress syndrome in nonpulmonary sepsis was restricted to patients with 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol levels consistent with active smoking and was robust to adjustment for other acute respiratory distress syndrome predictors. Cigarette smoke exposure as measured by history or 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol was not associated with acute respiratory distress syndrome in patients with other risk factors (e.g., pneumonia and aspiration). CONCLUSIONS: Cigarette smoking measured both by history and biomarker is associated with an increased risk of acute respiratory distress syndrome in patients with nonpulmonary sepsis. This finding has important implications for tobacco product regulation and for understanding the pathogenesis of acute respiratory distress syndrome.

Impact of advanced practice providers (nurse practitioners and physician assistants) on surgical residents' critical care experience.

BACKGROUND: Teaching hospitals often employ advanced practice providers (nurse practitioners and physician assistants or APPs) to counteract residents' work-hour restrictions. With increased utilization of APPs in labor-intense areas, such as intensive care units (ICUs), APPs may have an impact on resident education and experience. No studies have investigated the direct role an APP plays on the training experience of a surgical resident in the ICU. MATERIALS AND METHODS: An institutional review board-approved survey was emailed to residents in Accreditation Council for Graduate Medical Education-accredited general surgery programs. Surveys asked about demographics, residency and/or ICU characteristics, and the effects of APPs on patient care, workflow, and educational experience. Regression analysis determined predictors of resident perception. RESULTS: A total of 354 of 1178 residents responded to the survey (30%). Some residents felt that nurses calling APPs preferentially for patient-care issues interfered with education (17%) and residents' ability to follow patients (12%) and was associated with overall detrimental effects to ICU experience on regression (odds ratio, 3.7; confidence interval, 1.5-9.1). Most residents reported positive effects of APPs, such as reduced resident workload (79.8%), teaching protocols and/or guidelines (60.3%), enhanced patient care (60.3%), and enhanced communication (50.5%). When asked how APPs affected their overall ICU experience, 48.4% reported positive effects, 20.6% reported "no effect," and 31% reported detrimental effects. CONCLUSIONS: Only a minority of residents perceived that APPs detract from training, particularly those who felt excluded when nurses preferentially contact APPs with patient-care issues. APPs have the potential to enhance training and ICU experience, as reflected in many of the responses. Strategies to maintain direct nurse and resident communication might preserve residents' perception of the educational value of APPs.

Sex- and diagnosis-dependent differences in mortality and admission cytokine levels among patients admitted for intensive care.

OBJECTIVES: To investigate the role of sex on cytokine expression and mortality in critically ill patients. DESIGN: A cohort of patients admitted to were enrolled and followed over a 5-year period. SETTING: Two university-affiliated hospital surgical and trauma ICUs. PATIENTS: Patients 18 years old and older admitted for at least 48 hours to the surgical or trauma ICU. INTERVENTIONS: Observation only. MEASUREMENTS AND MAIN RESULTS: Major outcomes included admission cytokine levels, prevalence of ICU-acquired infection, and mortality during hospitalization conditioned on trauma status and sex. The final cohort included 2,291 patients (1,407 trauma and 884 nontrauma). The prevalence of ICU-acquired infection was similar for men (46.5%) and women (44.5%). All-cause in-hospital mortality was 12.7% for trauma male patient and 9.1% for trauma female patient (p = 0.065) and 22.9% for nontrauma male patients and 20.6% for nontrauma female patients (p = 0.40). Among trauma patients, logistic regression analysis identified female sex as protective for all-cause mortality (odds ratio, 0.57). Among trauma patients, men had significantly higher admission serum levels of interleukin-2, interleukin-12, interferon-γ, and tumor necrosis factor-α, and among nontrauma patients, men had higher admission levels of interleukin-8 and tumor necrosis factor-α. CONCLUSIONS: The relationship between sex and outcomes in critically ill patients is complex and depends on underlying illness. Women appear to be better adapted to survive traumatic events, while sex may be less important in other forms of critical illness. The mechanisms accounting for this gender dimorphism may, in part, involve differential cytokine responses to injury, with men expressing a more robust proinflammatory profile.

Association between cell-free hemoglobin, acetaminophen, and mortality in patients with sepsis: an observational study.

OBJECTIVE: To determine the association of circulating cell-free hemoglobin with poor clinical outcomes in patients with sepsis and to characterize the potential protective effects of acetaminophen, an inhibitor of hemoprotein-mediated oxidation. DESIGN: Retrospective observational study. PATIENTS: A total of 391 critically ill patients with sepsis in multiple ICUs in an academic tertiary care hospital. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Nonsurvivors had significantly higher plasma cell-free hemoglobin concentrations (median 20mg/dL, interquartile range 10-40) measured on enrollment compared to survivors (10mg/dL, interquartile range 10-30, p = 0.002). After controlling for potential confounders, patients with higher cell-free hemoglobin concentrations were significantly more likely to die in the hospital (odds ratio 1.078, 95% confidence interval 1.012-1.149, p = 0.02). In addition, receiving acetaminophen in the setting of increased cell-free hemoglobin was independently associated with a protective effect against death (odds ratio 0.48, 95% confidence interval 0.25-0.91, p = 0.026) and lower plasma concentrations of the lipid peroxidation product F2-isoprostanes (18.5 pg/mL, interquartile range 9-22.2) compared to no acetaminophen (42 pg/mL, interquartile range 29.7-86, p = 0.009). CONCLUSIONS: In critically ill patients with sepsis, elevated concentrations of circulating cell-free hemoglobin are independently associated with an increased risk of death. Acetaminophen may exert a protective effect by reducing cell-free hemoglobin-induced oxidative injury.

Twenty-year analysis of surgical resident operative trauma experiences.

BACKGROUND: The Accreditation Council for Graduate Medical Education (ACGME) implemented new work-hour rules for all U.S. residency programs beginning on July 1, 2003. The ACGME-mandated work-hour reform may have affected operative trauma case volumes of general surgery residents. METHODS: Using ACGME aggregate data collected from general surgery residency programs from 1990 to 2010, we examined the effect of the 2003 work-hour reform on resident operative trauma case volumes. RESULTS: Overall trauma cases per year declined from 78.28 in 1990 to 38.73 in 2010. From 1990 to 2003, laparotomy, burn, and upper-gastrointestinal trauma cases fell at least 50%, from 9.97 to 4.85 cases/resident by 0.46 cases/y (95% confidence interval [CI], 0.456-0.459), 10.05 to 3.30 cases/resident by 0.61 cases/y (95% CI, 0.609-0.617), and 3.34 to 1.01 cases/resident by 0.189 cases/y (95% CI, 0.188-0.189), respectively. After 2003, laparotomy and burn cases began to rise by 0.23 cases/y (95% CI, 0.228-0.231) and 0.36 cases/y (95% CI, 0.358-0.368). Vascular trauma cases continued to decline from 8.63 cases/resident by 0.197 (95% CI, 0.196-0.198) pre-reform, but by 0.102 (95% CI, 0.099-0.105) post-reform. Junior surgical residents were increasingly involved in trauma operative cases from 67% in 1990 to 79% in 2010. Cardiac, pancreatic, genitourinary, and neurosurgical cases did not peak more than 1.95 cases/resident pre-reform. CONCLUSIONS: Secular trends before the 2003 work-hour reform caused a 50% decrease in operative trauma experience among general surgery residents. Since 1990, junior residents have increasingly performed operative trauma. Rare trauma subspecialty cases remain rare. Post work-hour reform, operative trauma volumes have stabilized.

Biomarkers of lung epithelial injury and inflammation distinguish severe sepsis patients with acute respiratory distress syndrome.

INTRODUCTION: Despite recent modifications, the clinical definition of the acute respiratory distress syndrome (ARDS) remains non-specific, leading to under-diagnosis and under-treatment. This study was designed to test the hypothesis that a biomarker panel would be useful for biologic confirmation of the clinical diagnosis of ARDS in patients at risk of developing ARDS due to severe sepsis. METHODS: This was a retrospective case control study of 100 patients with severe sepsis and no evidence of ARDS compared to 100 patients with severe sepsis and evidence of ARDS on at least two of their first four ICU days. A panel that included 11 biomarkers of inflammation, fibroblast activation, proteolytic injury, endothelial injury, and lung epithelial injury was measured in plasma from the morning of ICU day two. A backward elimination model building strategy on 1,000 bootstrapped data was used to select the best performing biomarkers for further consideration in a logistic regression model for diagnosis of ARDS. RESULTS: Using the five best-performing biomarkers (surfactant protein-D (SP-D), receptor for advanced glycation end-products (RAGE), interleukin-8 (IL-8), club cell secretory protein (CC-16), and interleukin-6 (IL-6)) the area under the receiver operator characteristic curve (AUC) was 0.75 (95% CI: 0.7 to 0.84) for the diagnosis of ARDS. The AUC improved to 0.82 (95% CI: 0.77 to 0.90) for diagnosis of severe ARDS, defined as ARDS present on all four of the first four ICU days. CONCLUSIONS: Abnormal levels of five plasma biomarkers including three biomarkers generated by lung epithelium (SP-D, RAGE, CC-16) provided excellent discrimination for diagnosis of ARDS in patients with severe sepsis. Altered levels of plasma biomarkers may be useful biologic confirmation of the diagnosis of ARDS in patients with sepsis, and also potentially for selecting patients for clinical trials that are designed to reduce lung epithelial injury.

Association between haptoglobin, hemopexin and mortality in adults with sepsis.

INTRODUCTION: Plasma levels of cell-free hemoglobin are associated with mortality in patients with sepsis; however descriptions of independent associations with free hemoglobin and free heme scavengers, haptoglobin and hemopexin, are lacking beyond their description as acute phase reactants. We sought to determine the association of plasma levels of endogenous free hemoglobin and haptoglobin and hemopexin with in-hospital mortality in adults with sepsis. METHODS: We conducted a retrospective observational study of a total of 387 critically ill patients with sepsis in multiple intensive care units in an academic tertiary care hospital. Measurements of plasma haptoglobin and hemopexin were made on blood drawn within 24 hours of intensive care unit admission. The primary outcome was the association between plasma haptoglobin and hemopexin with in-hospital mortality. RESULTS: Survivors had significantly higher plasma haptoglobin concentrations (median 1234 µg/ml, interquartile range (IQR) 569 to 3037) and hemopexin concentrations (616 µg/ml, IQR 397 to 934) measured on enrollment compared to non-survivors (haptoglobin 750 µg/ml, IQR 404 to 2421, P = 0.008; hemopexin 470 µg/ml, IQR 303 to 891, P = 0.012). After controlling for potential confounders including cell-free hemoglobin concentration, patients with higher haptoglobin concentrations were significantly less likely to die in the hospital (odds ratio (OR) 0.653, 95% CI 0.433 to 0.984, P = 0.042), while the same association was not seen with hemopexin (OR 0.53, 95% CI 0.199 to 1.416, P = 0.206). In a subgroup analysis, the association between increased haptoglobin and hemopexin and decreased risk of mortality was no longer significant when analyzing patients with no detectable cell-free hemoglobin (P = 0.737 and P = 0.584, respectively). CONCLUSION: In critically ill patients with sepsis, elevated plasma levels of haptoglobin were associated with a decreased risk of in-hospital mortality and this association was independent of confounders. Increased haptoglobin may play a protective role in sepsis patients who have elevated levels of circulating cell-free hemoglobin beyond its previous description as an acute phase reactant.