Mechanical ventilation and acute lung injury in emergency department patients with severe sepsis and septic shock: an observational study

Partial pressure of carbon dioxide/pH interaction and its association with mortality among patients mechanically ventilated in the emergency department

OBJECTIVES

There is currently conflicting data as to the effects of hypercapnia on clinical outcomes among mechanically ventilated patients in the emergency department (ED). These conflicting results may be explained by the degree of acidosis. We sought to test the hypothesis that hypercapnia is associated with increased in-hospital mortality and decreased ventilator-free days at lower pH, but associated with decreased in-hospital mortality and increased ventilator-free days at higher pH, among patients requiring mechanical ventilation in the emergency department (ED).

METHODS

Secondary analysis of patient level data from prior clinical trials and cohort studies that enrolled adult patients who required mechanical ventilation in the ED. Patients who had a documented blood gas while on mechanical ventilation in the ED were included in these analyses. The primary outcome was in-hospital mortality, and secondary outcome was ventilator-free days. Mixed-effects logistic, linear, and survival-time regression models were used to test if pH modified the association between partial pressure of carbon dioxide (pCO2) and outcome measures.

RESULTS

Of the 2348 subjects included, the median [interquartile range (IQR)] pCO2 was 43 (35-54) and pH was 7.31 (7.22-7.39). Overall, in-hospital mortality was 27%. We found pH modified the association between pCO2 and outcomes, with higher pCO2 associated with increased probability of in-hospital mortality when pH is below 7.00, and decreased probability of in-hospital mortality when pH is above 7.10. These results remained consistent across multiple sensitivity and subgroup analyses. A similar relationship was found with ventilator-free days.

CONCLUSIONS

Higher pCO2 is associated with decreased mortality and greater ventilator-free days when pH is >7.10; however, it is associated with increased mortality and fewer ventilator-free days when the pH is below 7.00. Targeting pCO2 based on pH in the ED may be a potential intervention target for future clinical trials to improve clinical outcomes.

The impact of prolonged mechanical ventilation after acute type A aortic dissection repair

OBJECTIVE

Patients with type A aortic dissection have increased resource use. The objective of this study was to describe the relationship between prolonged mechanical ventilation and longitudinal survival in patients undergoing type A aortic dissection repair.

METHODS

We conducted a retrospective analysis of patients with type A aortic dissection undergoing repair from 2010 to 2018; Kaplan-Meier function and adjusted Cox regression analysis were used to compare in-hospital mortality and longitudinal survival accounting for time on mechanical ventilatory support.

RESULTS

A total of 552 patients were included. The study population was divided into 12 hours or less (n = 291), more than 12 to 24 or less hours (n = 101), more than 24 to 48 hours or less (n = 60), and more than 48 hours (n = 100) groups. Patients within the 12 or less hours group were the youngest (60.0 vs 63.5 years vs 63.6 vs 62.8 years; P = .03) and less likely to be female (31.6% vs 43.6% vs 46.7% vs 56.0%; P < .001). On the other hand, the more than 48 hours group presented with malperfusion syndrome at admission more often (24.4% vs 29.7% vs 28.3% vs 53.0%; P < .001) and had longer cardiopulmonary and ischemic times (P < .05). In-hospital mortality was significantly higher in the more than 48 hours group (5.2% vs 6.9% vs 3.3% vs 30.0%; P < .001). Multivariable analysis demonstrated worse longitudinal survival for the 24 to 48 hours group (hazard ratio, 1.94, confidence interval, 1.10-3.43) and more than 48 hours ventilation group (hazard ratio, 2.25, confidence interval, 1.30-3.92).

CONCLUSIONS

The need for prolonged mechanical ventilatory support is prevalent and associated with other perioperative complications. More important, after adjusting for other covariates, prolonged mechanical ventilation is an independent factor associated with increased longitudinal mortality.

Decreased Utilization of Low Tidal Volume Ventilation Outside of the Intensive Care Unit as Compared to Inside

Background: Investigations into the use of low tidal volume ventilation (LTVV) have been performed for patients in emergency departments (EDs) or intensive care units (ICUs). Practice differences between the ICU and non-ICU care areas have not been described. We hypothesized that the initial implementation of LTVV would be better inside ICUs than outside. Methods: This is a retrospective observational study of patients initiated on invasive mechanical ventilation (IMV) between January 1, 2016, and July 17, 2019. Initial recorded tidal volumes after intubation were used to compare the use of LTVV between care areas. Low tidal volume was considered 6.5 cc/kg of ideal body weight (IBW) or less. The primary outcome was the initiation of low tidal volume. Sensitivity analyses used a tidal volume of 8 cc/kg of IBW or less, and direct comparisons were performed between the ICU, ED, and wards. Results: There were 6392 initiations of IMV: 2217 (34.7%) in the ICU and 4175 (65.3%) outside. LTVV was more likely to be initiated in the ICU than outside (46.5% vs 34.2%; adjusted odds ratio [aOR] 0.62, 95% confidence interval [CI] 0.56-0.71, P < .01). The ICU also had more implementation when PaO2/FiO2 ratio was less than 300, (48.0% vs 34.6%; aOR 0.59, 95% CI 0.48-0.71, P < .01). When comparing individual locations, wards had lower odds of LTVV than the ICU (aOR 0.82, 95% CI 0.70-0.96, P  =  .02), the ED had lower odds than the ICU (aOR 0.55, 95% CI 0.48-0.63, P < .01), and the ED had lower odds than the wards (aOR 0.66, 95% CI 0.56-0.77, P < .01). Interpretation: Initial low tidal volumes were more likely to be initiated in the ICU than outside. This finding remained when examining only patients with a PaO2/FiO2 ratio less than 300. Care areas outside of the ICU do not employ LTVV as often as ICUs and are, therefore, a possible target for process improvement.

Implementation of Lung-Protective Ventilation in Patients With Acute Respiratory Failure

OBJECTIVES

We implemented a computerized protocol for low tidal volume ventilation (LTVV) to improve management and outcomes of mechanically ventilated patients with, and without, the acute respiratory distress syndrome (ARDS).

DESIGN

Pragmatic, nonrandomized stepped wedge type II hybrid implementation/effectiveness trial.

SETTING

Twelve hospitals in an integrated healthcare system over a 2-year period.

PATIENTS

Patients greater than or equal to 18 years old who had initiation of mechanical ventilation in the emergency department or ICU. We excluded patients who died or transitioned to comfort care on the day of admission to the ICU. We defined a subgroup of patients with ARDS for analysis.

INTERVENTIONS

Implementation of ventilator protocols for LTVV in the ICU.

MEASUREMENTS AND MAIN RESULTS

Our primary clinical outcome was ventilator-free days (VFDs) to day 28. Our primary process outcome was median initial set tidal volume. We included 8,692 mechanically ventilated patients, 3,282 (38%) of whom had ARDS. After implementation, set tidal volume reported as mL/kg predicted body weight decreased from median 6.1 mL/kg (interquartile range [IQR], 6.0-6.8 mL/kg) to 6.0 mL/kg (IQR, 6.0-6.6 mL/kg) ( p = 0.009). The percent of patients receiving LTVV (tidal volume ≤ 6.5 mL/kg) increased from 69.8% ( n = 1,721) to 72.5% ( n = 1,846) ( p = 0.036) after implementation. The percent of patients receiving greater than 8 mL/kg initial set tidal volume was reduced from 9.0% ( n = 222) to 6.7% ( n = 174) ( p = 0.005) after implementation. Among patients with ARDS, day 1 positive end-expiratory pressure increased from 6.7 to 8.0 cm H 2 O ( p < 0.001). We observed no difference in VFD (adjusted odds ratio, 1.06; 95% CI, 0.91-1.24; p = 0.44), or in secondary outcomes of length of stay or mortality, either within the main cohort or the subgroup of patients with ARDS.

CONCLUSIONS

We observed improved adherence to optimal ventilator management with implementation of a computerized protocol and reduction in the number of patients receiving tidal volumes greater than 8 mL/kg. We did not observe improvement in clinical outcomes.

The Practice Change and Clinical Impact of Lung-Protective Ventilation Initiated in the Emergency Department: A Secondary Analysis of Individual Patient-Level Data From Prior Clinical Trials and Cohort Studies

OBJECTIVES

Mechanically ventilated emergency department (ED) patients experience high morbidity and mortality. In a prior trial at our center, ED-based lung-protective ventilation was associated with improved care delivery and outcomes. Whether this strategy has persisted in the years after the trial remains unclear. The objective was to assess practice change and clinical outcomes associated with ED lung-protective ventilation.

DESIGN

Secondary analysis of individual patient-level data from prior clinical trials and cohort studies.

SETTING

ED and ICUs of a single academic center.

PATIENTS

Mechanically ventilated adults.

INTERVENTIONS

A lung-protective ventilator protocol used as the default approach in the ED.

MEASUREMENTS AND MAIN RESULTS

The primary ventilator-related outcome was tidal volume, and the primary clinical outcome was hospital mortality. Secondary outcomes included ventilator-, hospital-, and ICU-free days. Multivariable logistic regression, propensity score (PS)-adjustment, and multiple a priori subgroup analyses were used to evaluate outcome as a function of the intervention. A total of 1,796 patients in the preintervention period and 1,403 patients in the intervention period were included. In the intervention period, tidal volume was reduced from 8.2 mL/kg predicted body weight (PBW) (7.3-9.1) to 6.5 mL/kg PBW (6.1-7.1), and low tidal volume ventilation increased from 46.8% to 96.2% ( p < 0.01). The intervention period was associated with lower mortality (35.9% vs 19.1%), remaining significant after multivariable logistic regression analysis (adjusted odds ratio [aOR], 0.43; 95% CI, 0.35-0.53; p < 0.01). Similar results were seen after PS adjustment and in subgroups. The intervention group had more ventilator- (18.8 [10.1] vs 14.1 [11.9]; p < 0.01), hospital- (12.2 [9.6] vs 9.4 [9.5]; p < 0.01), and ICU-free days (16.6 [10.1] vs 13.1 [11.1]; p < 0.01).

CONCLUSIONS

ED lung-protective ventilation has persisted in the years since implementation and was associated with improved outcomes. These data suggest the use of ED-based lung-protective ventilation as a means to improve outcome.

Acute Respiratory Distress Syndrome

Acute respiratory distress syndrome (ARDS) occurs in up to 10% of patients with respiratory failure admitted through the emergency department. Use of noninvasive respiratory support has proliferated in recent years; clinicians must understand the relative merits and risks of these technologies and know how to recognize signs of failure. The cornerstone of ARDS care of the mechanically ventilated patient is low-tidal volume ventilation based on ideal body weight. Adjunctive therapies, such as prone positioning and neuromuscular blockade, may have a role in the emergency department management of ARDS depending on patient and department characteristics.

Mechanical Ventilation Practices and Low Tidal Volume Ventilation in Air Medical Transport Patients: The AIR-VENT Study

BACKGROUND

The management of mechanical ventilation critically impacts outcome for patients with acute respiratory failure. Ventilator settings in the early post-intubation period may be especially influential on outcome. Low tidal volume ventilation in the prehospital setting has been shown to impact the provision of low tidal volume after admission and influence outcome. However, there is an overall paucity of data on mechanical ventilation for air medical transport patients. The objectives of this study were to characterize air medical transport ventilation practices and assess variables associated with nonprotective ventilation.

METHODS

This was a multi-center, nationwide (approximately 130 bases) retrospective cohort study conducted on consecutive, adult mechanically ventilated air medical transport patients treated in the prehospital environment. Descriptive statistics were used to assess the cohort; the chi-square test compared categorical variables, and continuous variables were compared using independent samples t test or Mann-Whitney U test. To assess for predictors of nonprotective ventilation, a multivariable logistic regression model was constructed to adjust for potentially confounding variables. Low tidal volume ventilation was defined as a tidal volume of ≤ 8 mL/kg predicted body weight (PBW).

RESULTS

A total of 68,365 subjects were studied. Height was documented in only 4,186 (6.1%) subjects. Significantly higher tidal volume/PBW (8.6 [8.3-9.2] mL vs 6.5 [6.1-7.0] mL) and plateau pressure (20.0 [16.5-25.0] cm H2O vs 18.0 [15.0-22.0] cm H2O) were seen in the nonpro-tective ventilation group (P < .001 for both). According to sex, females received higher tidal volume/PBW compared to males (7.4 [6.6-8.0] mL vs 6.4 [6.0-6.8] mL, P < .001) and composed 75% of those subjects with nonprotective ventilation compared to 25% male, P < .001. After multivariable logistic regression, female sex was an independent predictor of nonprotective ventilation (adjusted odds ratio 6.79 [95% CI 5.47-8.43], P < .001).

CONCLUSIONS

The overwhelming majority of air medical transport subjects had tidal volume set empirically, which may be exposing patients to nonprotective ventilator settings. Given a lack of PBW assessments, the frequency of low tidal volume use remains unknown. Performance improvement initiatives aimed at indexing tidal volume to PBW are easy targets to improve the delivery of mechanical ventilation in the prehospital arena, especially for females.

Initiation of a Lung Protective Ventilation Strategy in the Emergency Department: Does an Emergency Department-Based ICU Make a Difference?

BACKGROUND:

Lung protective ventilation (LPV) is a key component in the management of acute respiratory distress syndrome and other acute respiratory pathology. Initiation of LPV in the emergency department (ED) is associated with improved patient-centered and system outcomes, but adherence to LPV among ED patients is low. The impact of an ED-based ICU (ED-ICU) on LPV adherence is not known.

METHODS:

This single-center, retrospective, cohort study analyzed rates of adherence to a multifaceted LPV strategy pre- and post-implementation of an ED-ICU. LPV strategy components included low tidal volume ventilation, avoidance of severe hyperoxia and high plateau pressures, and positive end-expiratory pressure settings in alignment with best-evidence recommendations. The primary outcome was adherence to the LPV strategy at time of ED departure.

RESULTS AND CONCLUSIONS:

A total of 561 ED visits were included in the analysis, of which 60.0% received some portion of their emergency care in the ED-ICU. Adherence to the LPV strategy was statistically significantly higher in the ED-ICU cohort compared with the pre-ED-ICU cohort (65.8% vs 41.4%; p < 0.001) and non-ED-ICU cohort (65.8% vs 43.1%; p < 0.001). Among the ED-ICU cohort, 92.8% of patients received low tidal volume ventilation. Care in the ED-ICU was also associated with shorter ICU and hospital length of stay. These findings suggest improved patient and resource utilization outcomes for mechanically ventilated ED patients receiving care in an ED-ICU.

Low Tidal Volume Ventilation for Emergency Department Patients: A Systematic Review and Meta-Analysis on Practice Patterns and Clinical Impact

OBJECTIVES

Data suggest that low tidal volume ventilation (LTVV) initiated in the emergency department (ED) has a positive impact on outcome. This systematic review and meta-analysis quantify the impact of ED-based LTVV on outcomes and ventilator settings in the ED and ICU.

DATA SOURCES

We systematically reviewed MEDLINE, EMBASE, Scopus, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, references, conferences, and ClinicalTrials.gov.

STUDY SELECTION

Randomized and nonrandomized studies of mechanically ventilated ED adults were eligible.

DATA EXTRACTION

Two reviewers independently screened abstracts. The primary outcome was mortality. Secondary outcomes included ventilation duration, lengths of stay, and occurrence rate of acute respiratory distress syndrome (ARDS). We assessed impact of ED LTVV interventions on ED and ICU tidal volumes.

DATA SYNTHESIS

The search identified 1,023 studies. Eleven studies (n = 12,912) provided outcome data and were meta-analyzed; 10 additional studies (n = 1,863) provided descriptive ED tidal volume data. Overall quality of evidence was low. Random effect meta-analytic models revealed that ED LTVV was associated with lower mortality (26.5%) versus non-LTVV (31.1%) (odds ratio, 0.80 [0.72-0.88]). ED LTVV was associated with shorter ICU (mean difference, -1.0; 95% CI, -1.7 to -0.3) and hospital (mean difference, -1.2; 95% CI, -2.3 to -0.1) lengths of stay, more ventilator-free days (mean difference, 1.4; 95% CI, 0.4-2.4), and lower occurrence rate (4.5% vs 8.3%) of ARDS (odds ratio, 0.57 [0.44-0.75]). ED LTVV interventions were associated with reductions in ED (-1.5-mL/kg predicted body weight [PBW] [-1.9 to -1.0]; p < 0.001) and ICU (-1.0-mL/kg PBW [-1.8 to -0.2]; p = 0.01) tidal volume.

CONCLUSIONS

The use of LTVV in the ED is associated with improved clinical outcomes and increased use of lung protection, recognizing low quality of evidence in this domain. Interventions aimed at implementing and sustaining LTVV in the ED should be explored.

Association of ROX Index with Mechanical Ventilator Use in Sepsis Patients in the Emergency Department

Detecting sepsis patients who are at a high-risk of mechanical ventilation is important in emergency departments (ED). The respiratory rate oxygenation (ROX) index is the ratio of tissue oxygen saturation/fraction of inspired oxygen to the respiratory rate. This study aimed to investigate whether the ROX index could predict mechanical ventilator use in sepsis patients in an ED. This retrospective observational study included quick sequential organ failure assessment (qSOFA) ≥ 2 sepsis patients that presented to the ED between September 2019 and April 2020. The ROX and ROX-heart rate (HR) indices were significantly lower in patients with mechanical ventilator use within 24 h than in those without the use of a mechanical ventilator (4.0 [3.2–5.4] vs. 10.0 [5.9–15.2], p < 0.001 and 3.9 [2.7–5.8] vs. 10.1 [5.4–16.3], p < 0.001, respectively). The area under the receiver operating characteristic (ROC) curve of the ROX and ROX-HR indices were 0.854 and 0.816 (both p < 0.001). The ROX and ROX-HR indices were independently associated with mechanical ventilator use within 24 h (adjusted hazard ratio = 0.78, 95% CI: 0.68–0.90, p < 0.001 and adjusted hazard ratio = 0.87, 95% CI 0.79–0.96, p = 0.004, respectively). The 28-day mortality was higher in the low ROX and low ROX-HR groups. The ROX and ROX-HR indices were associated with mechanical ventilator use within 24 h in qSOFA ≥ 2 patients in the ED.

Comparing the demographic data and outcomes of septic shock patients presenting to teaching or non-teaching metropolitan hospitals in the United States

BACKGROUND

Studies looking at the effect of hospital teaching status on septic shock related in-hospital mortality are lacking. The aim of this study was to examine the effect of hospital teaching status on mortality in septic shock patients in the United States.

METHODS

This was a retrospective observational study, using the Nationwide Emergency Department Sample Database (released in 2018). All patients with septic shock were included. Complex sample logistic regression was performed to assess the impact of hospital teaching status on patient mortality.

RESULTS

A total of 388,552 septic shock patients were included in the study. The average age was 66.93 years and 51.7% were males. Most of the patients presented to metropolitan teaching hospitals (68.2%) and 31.8% presented to metropolitan non-teaching hospitals. Septic shock patients presenting to teaching hospitals were found to have a higher percentage of medical comorbidities, were more likely to be intubated and placed on mechanical ventilation (50.5% vs. 46.9%) and had a longer average length of hospital stay (12.47 d vs. 10.20 d). Septic shock patients presenting to teaching hospitals had greater odds of in-hospital mortality compared to those presenting to metropolitan non-teaching hospitals (adjusted odd ratio [OR]=1.295, 95% confidence interval [CI]: 1.256-1.335).

CONCLUSION

Septic shock patients presenting to metropolitan teaching hospitals had significantly higher risks of mortality than those presenting to metropolitan non-teaching hospitals. They also had higher rates of intubation and mechanical ventilation as well as longer lengths of hospital stay than those in non-teaching hospitals.

Analysis of the correlation between the longitudinal trajectory of SOFA scores and prognosis in patients with sepsis at 72 hour after admission based on group trajectory modeling

Background

To identify the distinct trajectories of the Sequential Organ Failure Assessment (SOFA) scores at 72 h for patients with sepsis in the Medical Information Mart for Intensive Care (MIMIC)-IV database and determine their effects on mortality and adverse clinical outcomes.

Methods

A retrospective cohort study was carried out involving patients with sepsis from the MIMIC-IV database. Group-based trajectory modeling (GBTM) was used to identify the distinct trajectory groups for the SOFA scores in patients with sepsis in the intensive care unit (ICU). The Cox proportional hazards regression model was used to investigate the relationship between the longitudinal change trajectory of the SOFA score and mortality and adverse clinical outcomes.

Results

A total of 16,743 patients with sepsis were included in the cohort. The median survival age was 66 years (interquartile range: 54-76 years). The 7-day and 28-day in-hospital mortality were 6.0% and 17.6%, respectively. Five different trajectories of SOFA scores according to the model fitting standard were determined: group 1 (32.8%), group 2 (30.0%), group 3 (17.6%), group 4 (14.0%) and group 5 (5.7%). Univariate and multivariate Cox regression analyses showed that, for different clinical outcomes, trajectory group 1 was used as the reference, while trajectory groups 2-5 were all risk factors associated with the outcome (P < 0.001). Subgroup analysis revealed an interaction between the two covariates of age and mechanical ventilation and the different trajectory groups of patients' SOFA scores (P < 0.05).

Conclusion

This approach may help identify various groups of patients with sepsis, who may be at different levels of risk for adverse health outcomes, and provide subgroups with clinical importance.

A Target for Increased Mortality Risk in Critically Ill Patients: The Concept of Perpetuity

Background: Emergency medicine is acuity-based and focuses on time-sensitive treatments for life-threatening diseases. Prolonged time in the emergency department, however, is associated with higher mortality in critically ill patients. Thus, we explored management after an acuity-based intervention, which we call perpetuity, as a potential mechanism for increased risk. To explore this concept, we evaluated the impact of each hour above a lung-protective tidal volume on risk of mortality. Methods: This cohort analysis includes all critically ill, non-trauma, adult patients admitted to two academic EDs between 1 November 2013 and 30 April 2017. Cox models with time-varying covariates were developed with time in perpetuity as a time-varying covariate, defined as hours above 8 mL/kg ideal body weight, adjusted for covariates. The primary outcome was the time to in-hospital death. Results: Our analysis included 2025 patients, 321 (16%) of whom had at least 1 h of perpetuity time. A partial likelihood-ratio test comparing models with and without hours in perpetuity was statistically significant (χ²(3) = 13.83, p = 0.0031). There was an interaction between age and perpetuity (Relative risk (RR) 0.9995; 95% Confidence interval (CI₉₅): 0.9991–0.9998). For example, for each hour above 8 mL/kg ideal body weight, a 20-year-old with 90% oxygen saturation has a relative risk of death of 1.02, but a 40-year-old with 90% oxygen saturation has a relative risk of 1.01. Conclusions: Perpetuity, illustrated through the lens of mechanical ventilation, may represent a target for improving outcomes in critically ill patients, starting in the emergency department. Research is needed to evaluate the types of patients and interventions in which perpetuity plays a role.

Factors Associated With Poor Long-Term Outcomes After Emergency Department Intubation

Introduction

While immediate complications of ED patients undergoing endotracheal intubation (ETI) have been explored, the relationship between ED ETI and patient status at hospital discharge is unknown.

Methods

We performed a retrospective review of all intubations performed in our ED for one calendar year in adult patients (>18 years of age). We abstracted patient and ETI factors (indication, complications, etc.) to determine their impact on patient outcomes. We defined a poor outcome as either (1) death or discharge to a nursing home if admitted to the hospital from home or (2) death if admitted to the hospital from a nursing home. We examined the univariate odds ratios for poor outcomes. 

Results

We identified 122 intubations; 64 (52.5%) had a poor outcome and 58 (47.5%) did not have a poor outcome. Age in years (odds ratio [OR] 1.04, 95% confidence interval [CI] 1.02-1.07) and ETI performed for an indication of "cardiac arrest" (OR 4.49, 95% CI 1.55-13.01) were the only variables associated with a poor outcome. Other patients and intubation variables were not associated with a poor outcome including; gender, difficult airway characteristics, intubator skill level, first attempt success, airway complications, and post-intubation hypoxia or hypotension.

Conclusion

In our sample from a single ED, over 50% of patients who undergo ED ETI either died in the hospital or failed to return home. While age and an ETI indication of "cardiac arrest" were associated with poor outcomes, future work is required to validate our findings in a larger cohort.

Attributable mortality of acute respiratory distress syndrome: a systematic review, meta-analysis and survival analysis using targeted minimum loss-based estimation

BACKGROUND

Although acute respiratory distress syndrome (ARDS) is associated with high mortality, its direct causal link with death is unclear. Clarifying this link is important to justify costly research on prevention of ARDS.

OBJECTIVE

To estimate the attributable mortality, if any, of ARDS.

DESIGN

First, we performed a systematic review and meta-analysis of observational studies reporting mortality of critically ill patients with and without ARDS matched for underlying risk factor. Next, we conducted a survival analysis of prospectively collected patient-level data from subjects enrolled in three intensive care unit (ICU) cohorts to estimate the attributable mortality of critically ill septic patients with and without ARDS using a novel causal inference method.

RESULTS

In the meta-analysis, 44 studies (47 cohorts) involving 56 081 critically ill patients were included. Mortality was higher in patients with versus without ARDS (risk ratio 2.48, 95% CI 1.86 to 3.30; p<0.001) with a numerically stronger association between ARDS and mortality in trauma than sepsis. In the survival analysis of three ICU cohorts enrolling 1203 critically ill patients, 658 septic patients were included. After controlling for confounders, ARDS was found to increase the mortality rate by 15% (95% CI 3% to 26%; p=0.015). Significant increases in mortality were seen for severe (23%, 95% CI 3% to 44%; p=0.028) and moderate (16%, 95% CI 2% to 31%; p=0.031), but not for mild ARDS.

CONCLUSIONS

ARDS has a direct causal link with mortality. Our findings provide information about the extent to which continued funding of ARDS prevention trials has potential to impart survival benefit.

PROSPERO REGISTRATION NUMBER

CRD42017078313.

The ED-AWARENESS Study: A Prospective, Observational Cohort Study of Awareness With Paralysis in Mechanically Ventilated Patients Admitted From the Emergency Department

STUDY OBJECTIVE

Awareness with paralysis is a devastating complication for patients receiving mechanical ventilation and risks long-term psychological morbidity. Data from the emergency department (ED) demonstrate a high rate of longer-acting neuromuscular blocking agent use, delayed analgosedation, and a lack of sedation depth monitoring. These practices are discordant with recommendations for preventing awareness with paralysis. Despite this, awareness with paralysis has not been rigorously studied in the ED population. Our objective is to assess the prevalence of awareness with paralysis in ED patients receiving mechanical ventilation.

METHODS

This was a single-center, prospective, observational cohort study on 383 mechanically ventilated ED patients. After extubation, we assessed patients for awareness with paralysis by using the modified Brice questionnaire. Three expert reviewers independently adjudicated awareness with paralysis. We report the prevalence of awareness with paralysis (primary outcome); the secondary outcome was perceived threat, a mediator for development of posttraumatic stress disorder.

RESULTS

The prevalence of awareness with paralysis was 2.6% (10/383). Exposure to rocuronium at any point in the ED was significantly different between patients who experienced awareness with paralysis (70%) versus the rest of the cohort (31.4%) (unadjusted odds ratio 5.1; 95% confidence interval 1.30 to 20.1). Patients experiencing awareness with paralysis had higher mean values on the threat perception scale, denoting a higher degree of perceived threat, compared with patients who did not experience awareness with paralysis (13.4 [SD 7.7] versus 8.5 [SD 6.2]; mean difference 4.9; 95% confidence interval 0.94 to 8.8).

CONCLUSION

Awareness with paralysis occurs in a significant minority of ED patients who receive mechanical ventilation. Potential associations of awareness with paralysis with ED care and increased perceived threat warrant further evaluation.

A study protocol for a multicentre, prospective, before-and-after trial evaluating the feasibility of implementing targeted SEDation after initiation of mechanical ventilation in the emergency department (The ED-SED Pilot Trial)

INTRODUCTION

Sedation is a cornerstone therapy in the management of patients receiving mechanical ventilation and is highly influential on outcome. Early sedation depth appears especially influential, as early deep sedation is associated with worse outcome when compared with light sedation. Our research group has shown that patients receiving mechanical ventilation in the emergency department (ED) are exposed to deep sedation commonly, and ED sedation depth is impactful on intensive care unit (ICU) care and clinical outcomes. While extensive investigation has occurred for patients in the ICU, comparatively little data exist from the ED. Given the influence that ED sedation seems to carry, as well as a lack of ED-based sedation trials, there is significant rationale to investigate ED-based sedation as a means to improve outcome.

METHODS AND ANALYSIS

This is a multicentre (n=3) prospective, before-and-after pilot trial examining the feasibility of implementing targeted sedation in the immediate postintubation period in the ED. A cohort of 344 patients receiving mechanical ventilation in ED will be included. Feasibility outcomes include: (1) participant recruitment; (2) proportion of Richmond Agitation-Sedation Scale (RASS) scores in the deep sedation range; (3) reliability (agreement) of RASS measurements performed by bedside ED nurses; and (4) adverse events. The proportion of deep sedation measurements before and after the intervention will be compared using the χ² test. Logistic regression will be used to compare before-and-after differences, adjusting for potential confounders. The inter-rater correlation coefficient will be used to assess paired observations between a study team member and bedside ED nurses, and to describe reliability of RASS measurements.

ETHICS AND DISSEMINATION

The Human Research Protection Office at Washington University in St. Louis School of Medicine has approved the study. The publication of peer-reviewed manuscripts and the presentation of abstracts at scientific meetings will be used to disseminate the work.

REGISTRATION

ClinicalTrials.gov identifier NCT04410783; Pre-results.

Association of an Emergency Department-embedded Critical Care Unit with Hospital Outcomes and Intensive Care Unit Use

Rationale: A small but growing number of hospitals are experimenting with emergency department-embedded critical care units (CCUs) in an effort to improve the quality of care for critically ill patients with sepsis and acute respiratory failure (ARF).Objectives: To evaluate the potential impact of an emergency department-embedded CCU at the Hospital of the University of Pennsylvania among patients with sepsis and ARF admitted from the emergency department to a medical ward or intensive care unit (ICU) from January 2016 to December 2017.Methods: The exposure was eligibility for admission to the emergency department-embedded CCU, which was defined as meeting a clinical definition for sepsis or ARF and admission to the emergency department during the intervention period on a weekday. The primary outcome was hospital length of stay (LOS); secondary outcomes included total emergency department plus ICU LOS, hospital survival, direct admission to the ICU, and unplanned ICU admission. Primary interrupted time series analyses were performed using ordinary least squares regression comparing monthly means. Secondary retrospective cohort and before-after analyses used multivariable Cox proportional hazard and logistic regression.Results: In the baseline and intervention periods, 3,897 patients met the inclusion criteria for sepsis and 1,865 patients met the criteria for ARF. Among patients admitted with sepsis, opening of the emergency department-embedded CCU was not associated with hospital LOS (β = -1.82 d; 95% confidence interval [CI], -4.50 to 0.87; P = 0.17 for the first month after emergency department-embedded CCU opening compared with baseline; β = -0.26 d; 95% CI, -0.58 to 0.06; P = 0.10 for subsequent months). Among patients admitted with ARF, the emergency department-embedded CCU was not associated with a significant change in hospital LOS for the first month after emergency department-embedded CCU opening (β = -3.25 d; 95% CI, -7.86 to 1.36; P = 0.15) but was associated with a 0.64 d/mo shorter hospital LOS for subsequent months (β = -0.64 d; 95% CI, -1.12 to -0.17; P = 0.01). This result persisted among higher acuity patients requiring ventilatory support but was not supported by alternative analytic approaches. Among patients admitted with sepsis who did not require mechanical ventilation or vasopressors in the emergency department, the emergency department-embedded CCU was associated with an initial 9.9% reduction in direct ICU admissions in the first month (β = -0.099; 95% CI, -0.153 to -0.044; P = 0.002), followed by a 1.1% per month increase back toward baseline in subsequent months (β = 0.011; 95% CI, 0.003-0.019; P = 0.009). This relationship was supported by alternative analytic approaches and was not seen in ARF. No associations with emergency department plus ICU LOS, hospital survival, or unplanned ICU admission were observed among patients with sepsis or ARF.Conclusions: The emergency department-embedded CCU was not associated with clinical outcomes among patients admitted with sepsis or ARF. Among less sick patients with sepsis, the emergency department-embedded CCU was initially associated with reduced rates of direct ICU admission from the emergency department. Additional research is necessary to further evaluate the impact and utility of the emergency department-embedded CCU model.

Maresin1 ameliorates sepsis-associated lung injury by inhibiting the activation of the JAK2/STAT3 and MAPK/ NF-κB signaling pathways

Sepsis-associated acute lung injury (ALI) is a clinically critical disease that carries a high mortality rate. The pathogenesis of sepsis-associated ALI has not yet been precisely elucidated and there is a lack of effective treatment. As a new endogenous docosahexaenoic acid (DHA)-derived lipid mediators, Maresin1 has a significant dual role of anti-inflammatory and promoting inflammation regression. In this study, we established the sepsis model by the cecal ligation and puncture method (CLP) to explore the effect of Maresin1 on sepsis-induced lung injury. We found that the intervention of Maresin1 could significantly attenuate the sepsis-induced inflammatory responses, characterized by the down-regulation of the level of IL-1β, IL-6, TNF-α, MPO, etc. Maresin1 could also significantly decrease the number of neutrophils in lung tissue, thus improving the related lung injury indicators. Our experiment clarified that the protective effect of Maresin1 on sepsis-associated lung injury is closely related to its inhibition function of JAK2/STAT3 and MAPK/NF-κB signaling pathways. Our findings provide new research directions and therapeutic targets for sepsis-associated ALI.

The protective effect and mechanism of lentinan on acute kidney injury in septic rats

BACKGROUND

This study aimed to investigate the protective effect and mechanism of lentinan (LNT) on acute kidney injury (AKI) in septic rats.

METHODS

A total 72 male SD rats were randomly divided into 6 groups with 12 rats in each group. Except for the sham group, all groups, including the burn sepsis group (BS group), the positive drug control group (dexamethasone, 5 mg/kg, PC group), the LNT low-concentration group (LNT-L group) (50 mg/kg), the LNT medium-concentration group (LNT-M group) (100 mg/kg), and the LNT high-concentration group (LNT-H group) (200 mg/kg), were intraperitoneally injected with the same amount of normal saline 30 min before injury. The levels of serum interleukin (IL)-4, IL-6, IL-10, and tumor necrosis factor alpha (TNF-α); the indexes of blood urea nitrogen (BUN) and creatinine (Cr); and the protein expression levels of inducible nitric oxide synthase (iNOS), intercellular adhesion molecule 1 (ICAM-1), and nuclear factor-κB (NF-κB) in renal tissue were detected 24 hours after the model was established.

RESULTS

Compared with the sham group, the BUN and Cr of the other groups were significantly higher, while those of the LNT group with different concentrations were significantly lower than those of the BS group (P<0.05). Compared with the sham group, the protein expression levels of NF-κB, iNOS, and ICAM-1 along with the levels of pro-inflammatory factors TNF-α and IL-6 in serum were significantly increased, while the levels of anti-inflammatory factors IL-4 and IL-10 were obviously lower in the BS group. Compared with the BS group, the protein expression levels of NF-κB, iNOS, and ICAM-1 along with the levels of pro-inflammatory factors TNF-α and IL-6 in serum were significantly decreased, while the levels of anti-inflammatory factors IL-4 and IL-10 were obviously increased in the LNT group with different concentrations..

CONCLUSIONS

LNT has a certain protective effect on AKI in septic rats, and its mechanism may involve inhibiting the activation of NF-κB, which suppresses the expression of proinflammatory factors in turn, thus promoting the release of anti-inflammatory factors.

Temporal Changes in Ventilator Settings in Patients With Uninjured Lungs: A Systematic Review

In patients with uninjured lungs, increasing evidence indicates that tidal volume (VT) reduction improves outcomes in the intensive care unit (ICU) and in the operating room (OR). However, the degree to which this evidence has translated to clinical changes in ventilator settings for patients with uninjured lungs is unknown. To clarify whether ventilator settings have changed, we searched MEDLINE, Cochrane Central Register of Controlled Trials, and Web of Science for publications on invasive ventilation in ICUs or ORs, excluding those on patients <18 years of age or those with >25% of patients with acute respiratory distress syndrome (ARDS). Our primary end point was temporal change in VT over time. Secondary end points were changes in maximum airway pressure, mean airway pressure, positive end-expiratory pressure, inspiratory oxygen fraction, development of ARDS (ICU studies only), and postoperative pulmonary complications (OR studies only) determined using correlation analysis and linear regression. We identified 96 ICU and 96 OR studies comprising 130,316 patients from 1975 to 2014 and observed that in the ICU, VT size decreased annually by 0.16 mL/kg (-0.19 to -0.12 mL/kg) (P < .001), while positive end-expiratory pressure increased by an average of 0.1 mbar/y (0.02-0.17 mbar/y) (P = .017). In the OR, VT size decreased by 0.09 mL/kg per year (-0.14 to -0.04 mL/kg per year) (P < .001). The change in VTs leveled off in 1995. Other intraoperative ventilator settings did not change in the study period. Incidences of ARDS (ICU studies) and postoperative pulmonary complications (OR studies) also did not change over time. We found that, during a 39-year period, from 1975 to 2014, VTs in clinical studies on mechanical ventilation have decreased significantly in the ICU and in the OR.

Human Adipose Tissue-Derived Stromal Cells Attenuate the Multiple Organ Injuries Induced by Sepsis and Mechanical Ventilation in Mice

Mechanical ventilation (MV) can augment sepsis-induced organ injury. Previous studies indicate that human mesenchymal stem cells (hMSCs) have immune-modulatory effect. We hypothesize that human adipose tissue-derived stromal cells (hADSCs) could attenuate MV and sepsis-induced organ injury. Male C57BL/6 mice were randomized to five groups: Sham group; MV group; cecal ligation and puncture (CLP) group; CLP + MV group; and CLP + MV + hADSC group. Anesthetized mice were subjected to cecal ligation and puncture surgery. The mice then received mechanical ventilation (12 ml/kg), with or without the intervention of hADSCs. The survival rate, organ injury of the liver and kidney, total protein and cells in bronchoalveolar lavage fluid (BALF), and histological changes of the lung and liver were examined. The level of IL-6 in BALF was measured by ELISA. Real-time quantitative PCR was used to analyze mRNA of IL-6 and tumor necrosis factor-α (TNF-α). hADSC treatment increased survival rate of septic mice with MV. hADSCs attenuated dysfunction of the liver and kidney and decreased lung inflammation and tissue injury of the liver and lung. IL-6 level in BALF and TNF-α and IL-6 mRNA expression in the tissue of the lung, liver, and kidney were significantly reduced by hADSC treatment. MV with conventional tidal volume aggravates CLP-induced multiple organ injuries. hADSCs inhibited the compound injuries possibly through modulation of immune responses.

Invasive mechanical ventilation in the emergency department

Emergency department (ED) lenght of stay of the patients requiring admission to the intensive care units has increased gradually in recent years. Mechanical ventilation is an integral part of critical care and mechanically ventilated patients have to be managed and monitored by emergency physicians for longer than expected in EDs. This early period of care has significant impact on the outcomes of these patients. Therefore, emergency physicians should have comprehensive knowledge of mechanical ventilation. This review will summarize the current literature of the basic concepts, appropriate clinical applications, monitoring parameters, components and mechanisms of mechanical ventilation in the ED.

The effect of emergency department crowding on lung-protective ventilation utilization for critically ill patients

OBJECTIVE

To measure effects of ED crowding on lung-protective ventilation (LPV) utilization in critically ill ED patients.

METHODS

This is a retrospective cohort study of adult mechanically ventilated ED patients admitted to the medical intensive care unit (MICU), over a 3.5-year period at a single academic tertiary care hospital. Clinical data, including reason for intubation, severity of illness (MPM₀-III), acute respiratory distress syndrome (ARDS) risk score (EDLIPS), and ventilator settings were extracted via electronic query of electronic health record and standardized chart abstraction. Crowding metrics were obtained at 5-min intervals and averaged over the ED stay, stratified by acuity and disposition. Multivariate logistic regression was used to predict likelihood of LPV prior to ED departure.

RESULTS

Mechanical ventilation was used in 446 patients for a median ED duration of 3.7 h (interquartile ratio, IQR, 2.3, 5.6). Mean MPM₀-III score was 32.5 ± 22.7, with high risk for ARDS (EDLIPS ≥5) seen in 373 (82%) patients. Initial and final ED ventilator settings differed in 134 (30.0%) patients, of which only 47 (35.1%) involved tidal volume changes. Higher percentages of active ED patients (workup in-progress) and those requiring eventual admission were associated with lower odds of LPV utilization by ED departure (OR 0.97, 95%CI 0.94-1.00; OR 0.97, 95%CI 0.94-1.00, respectively). In periods of high volume, ventilator adjustments to settings other than the tidal volume were associated with higher odds of LPV utilization. Reason for intubation, MPM₀-III, and EDLIPS were not associated with LPV utilization, with no interactions detected in times of crowding.

CONCLUSIONS

ED patients remain on suboptimal tidal volume settings with infrequent ventilator adjustments during the ED stay. Hospitals should focus on both systemic factors and bedside physician and/or respiratory therapist interventions to increase LPV utilization in times of ED boarding and crowding for all patients.

Rationale and design of a prospective, multicentre, randomised, conventional treatment-controlled, parallel-group trial to evaluate the efficacy and safety of ulinastatin in preventing acute respiratory distress syndrome in high-risk patients

INTRODUCTION

Acute respiratory distress syndrome (ARDS) is challenging in the intensive care unit (ICU). Although pharmacotherapy for ARDS has gained increasing attention, most trials have yielded negative results. Patients with ARDS have usually been recruited as subjects; the inflammatory reaction has already expanded into a cascade at this point, and its severity is sufficient to damage the lung parenchyma. This raises the question of whether early treatment can prevent ARDS and the associated lung injury. We hypothesise that ARDS is preventable in high-risk patients by administration of ulinastatin as an anti-inflammatory drug before ARDS onset, and we are performing a study to test ulinastatin, a protease inhibitor, versus treatment-as-usual in a group of patients at increased risk for ARDS.

METHODS AND ANALYSIS

This report presents the protocol for a multicentre, randomised, conventional treatment-controlled, parallel group study to prevent the development of ARDS using ulinastatin in high-risk patients. The study population will comprise patients at risk of ARDS in the ICU (≥18 years of age and Lung Injury Prediction Score of >4); patients with confirmed ARDS and some other conditions (immunodeficiency, use of some drugs, etc.) will be excluded. The enrolled patients will be randomly allocated to an ulinastatin group (ulinastatin will be intravenously administered every 8 hours for a total of 600 000 U/day for five consecutive days) or control group. The efficacy of ulinastatin in preventing ARDS development will be evaluated by the incidence rate of ARDS as the primary outcome; the secondary outcomes include the severity of ARDS, clinical outcome, extrapulmonary organ function and adverse events incurred by ulinastatin. Based on the results of preliminary studies and presuming the incidence of ARDS will decrease by 9% in high-risk patients, 880 patients are needed to obtain statistical power of 80%.

ETHICS AND DISSEMINATION

This study has been approved by the Peking University Third Hospital Medical Science Research Ethics Committee. The findings will be published in peer-reviewed journals and presented at national and international conferences.

TRIAL REGISTRATION NUMBER

NCT03089957; Pre-results.

Prospective Assessment of the Feasibility of a Trial of Low-Tidal Volume Ventilation for Patients with Acute Respiratory Failure

RATIONALE

Low-tidal volume ventilation (LTVV; 6 ml/kg) benefits patients with acute respiratory distress syndrome and may aid those with other causes of respiratory failure. Current early ventilation practices are poorly defined.

OBJECTIVES

We observed patients with acute respiratory failure to assess the feasibility of a pragmatic trial of LTVV and to guide experimental design.

METHODS

We prospectively enrolled consecutive patients with acute respiratory failure admitted to intensive care units expected to participate in the proposed trial. We collected clinical data as well as information on initial and daily ventilator settings and inpatient mortality. We estimated the benefit of LTVV using predictive linear and nonlinear models. We simulated models to estimate power and feasibility of a cluster-randomized trial of LTVV versus usual care in acute respiratory failure.

RESULTS

We included 2,484 newly mechanically ventilated patients (31% with acute respiratory distress syndrome) from 49 hospitals. Hospital mortality was 28%. Mean initial tidal volume was 7.1 ml/kg predicted body weight (95% confidence interval, 7.1-7.2), with 78% of patients receiving tidal volumes less than or equal to 8 ml/kg. Our models estimated a mortality benefit of 0-2% from LTVV compared with usual care. Simulation of a stepped-wedged cluster-randomized trial suggested that enrollment of 106,361 patients would be necessary to achieve greater than 90% power.

CONCLUSIONS

Use of initial tidal volumes less than 8 ml/kg predicted body weight was common at hospitals participating in the National Heart, Lung, and Blood Institute Prevention and Early Treatment of Acute Lung Injury (PETAL) Network. After considering the size and budgetary requirement for a cluster-randomized trial of LTVV versus usual care in acute respiratory failure, the PETAL Network deemed the proposed trial infeasible. A rapid observational study and simulations to model anticipated power may help better design trials.

Effects of hypercapnia in sepsis: protocol for a systematic review of clinical and preclinical data

BACKGROUND

Respiratory failure requiring mechanical ventilation is a common manifestation of end-organ damage among patients with sepsis and has a high morbidity and mortality rate, as well as substantial associated treatment costs. Considering the burden of this condition, there is great need to identify novel, pragmatic therapies to improve outcomes in this population. Hypercapnia has shown benefits in several different ex vivo and in vivo models of lung injury. However, it is currently unclear if hypercapnia can confer clinical benefit among patients with sepsis. The objective of this systematic review is to collate the biomedical literature of preclinical and clinical studies testing the effects of higher PaCO₂ levels in the setting of sepsis.

METHODS

We will perform a qualitative systematic review of preclinical and clinical studies evaluating the effects of hypercapnia in sepsis. We will search CENTRAL, PubMed, CINAHL, and EMBASE using a comprehensive strategy. We will screen the reference lists of the articles we select for inclusion to identify additional studies for potential inclusion. Two independent reviewers will review all search results. Upon inclusion of articles, we will extract data using a standardized form. We will use tables to describe the study type, population included, exposure and control groups, outcome measures, and effects of exposure on outcome measures compared to controls.

DISCUSSION

This systematic review aims to synthesize the world's literature on the effects of hypercapnia in the setting of sepsis. We expect this systematic review will find that majority of the studies will demonstrate a potential benefit of higher PaCO₂ levels in sepsis. The results of this systematic review will contribute to the understanding of the effects of hypercapnia in the setting of sepsis and promote future research of PaCO₂ management in mechanically ventilated patients with sepsis.

SYSTEMATIC REVIEW REGISTRATION

The systematic review is registered in the PROSPERO international prospective register of systematic review (PROSPERO # CRD42018086703 ).

Effects of cisatracurium in combination with ventilation on inflammatory factors and immune variations in sepsis rats

The effects of cisatracurium in combination with ventilation on inflammatory factors and immune variations in sepsis rats were investigated. A total of 54 male Sprague-Dawley rats were selected and divided randomly into three groups: Sham group (n=6), model group (n=24) and experiment group (n=24). Rats in the model and experiment groups underwent cecal ligation and puncture (CLP) for establishment of sepsis model. Rats in experiment group additionally received cisatracurium medication in combination with ventilation for treatment. At 6, 12 and 24 h after CLP, the levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6 and procalcitonin (PCT) in serum and the ratio of leukocyte to neutrophil in peripheral blood was also detected. Twenty-four hours later, the expression of high mobility group box 1 (HMGB1) in lung tissues and cluster of differentiation (CD) 4⁺ and CD8⁺ in T-lymphocyte subsets were also detected, and the wet/dry (W/D) ratio of lung was measured. Compared with that in model group, the levels of inflammatory factors in the experiment group were significantly decreased, while the indicators in assays of cellular immunity were obviously elevated. Ratio of leukocyte to neutrophil in peripheral blood was significantly decreased after treatment. Cisatracurium in combination with ventilation can alleviate the inflammatory injury to organs in sepsis rats through inhibiting the inflammatory responses and regulating the immune functions, which manifests a new significance in guiding the clinical diagnosis and treatment.

Prognosis After Emergency Department Intubation to Inform Shared Decision-Making

OBJECTIVES

To inform the shared decision-making process between clinicians and older adults and their surrogates regarding emergency intubation.

DESIGN

Retrospective cohort study.

SETTING

Multicenter, emergency department (ED)-based cohort.

PARTICIPANTS

Adults aged 65 and older intubated in the ED from 2008 to 2015 from 262 hospitals across the United States (>95% of U.S. nonprofit academic medical centers).

MEASUREMENTS

Our primary outcome was age-specific in-hospital mortality. Secondary outcomes were age-specific odds of death after adjusting for race, comorbid conditions, admission diagnosis, hospital disposition, and geographic region.

RESULTS

We identified 41,463 ED intubation encounters and included 35,036 in the final analysis. Sixty-four percent were in non-Hispanic whites and 54% in women. Overall in-hospital mortality was 33% (95% confidence interval (CI)=34-35%). Twenty-four percent (95% CI=24-25%) of subjects were discharged to home, and 41% (95% CI=40-42%) were discharged to a location other than home. Mortality was 29% (95% CI=28-29%) for individuals aged 65 to 74, 34% (95% CI=33-35%) for those aged 75 to 79, 40% (95% CI=39-41%) for those aged 80 to 84, 43% (95% CI=41-44%) for those aged 85 to 89, and 50% (95% CI=48-51%) for those aged 90 and older.

CONCLUSION

After emergency intubation, 33% percent of older adults die during the index hospitalization. Only 24% of survivors are discharged to home. Simple, graphic representations of this information, in combination with an experienced clinician's overall clinical assessment, will support shared decision-making regarding unplanned intubation.

Emergency department hyperoxia is associated with increased mortality in mechanically ventilated patients: a cohort study

BACKGROUND

Providing supplemental oxygen is fundamental in the management of mechanically ventilated patients. Increasing amounts of data show worse clinical outcomes associated with hyperoxia. However, these previous data in the critically ill have not focused on outcomes associated with brief hyperoxia exposure immediately after endotracheal intubation. Therefore, the objectives of this study were to evaluate the impact of isolated early hyperoxia exposure in the emergency department (ED) on clinical outcomes among mechanically ventilated patients with subsequent normoxia in the intensive care unit (ICU).

METHODS

This was an observational cohort study conducted in the ED and ICUs of an academic center in the USA. Mechanically ventilated normoxic (partial pressure of arterial oxygen (P_aO₂) 60-120 mm Hg) ICU patients with mechanical ventilation initiated in the ED were studied. The cohort was categorized into three oxygen exposure groups based on P_aO₂ values obtained after ED intubation: hypoxia, normoxia, and hyperoxia (defined as P_aO₂ < 60 mmHg, P_aO₂ 60-120 mm Hg, and P_aO₂ > 120 mm Hg, respectively, based on previous literature).

RESULTS

A total of 688 patients were included. ED normoxia occurred in 350 (50.9%) patients, and 300 (43.6%) had exposure to ED hyperoxia. The ED hyperoxia group had a median (IQR) ED P_aO₂ of 189 mm Hg (146-249), compared to an ED P_aO₂ of 88 mm Hg (76-101) in the normoxia group, P < 0.001. Patients with ED hyperoxia had greater hospital mortality (29.7%), when compared to those with normoxia (19.4%) and hypoxia (13.2%). After multivariable logistic regression analysis, ED hyperoxia was an independent predictor of hospital mortality (adjusted OR 1.95 (1.34-2.85)).

CONCLUSIONS

ED exposure to hyperoxia is common and associated with increased mortality in mechanically ventilated patients achieving normoxia after admission. This suggests that hyperoxia in the immediate post-intubation period could be particularly injurious, and targeting normoxia from initiation of mechanical ventilation may improve outcome.

Emergency Department Length of Stay for Critical Care Admissions. A Population-based Study

RATIONALE

Hospital emergency department (ED) strain is common in North America. Excessive strain may result in prolonged ED length of stay and may lead to worse outcomes for patients admitted to intensive care units (ICUs).

OBJECTIVES

To describe patient, ED, and hospital characteristics associated with prolonged ED length of stay for adult patients admitted from EDs to ICUs.

METHODS

We conducted a population-based cohort study in the Province of Ontario, Canada, including patients admitted to an adult ICU from an ED and excluding only interhospital transfers and scheduled visits. Using regression modeling, we examined associations between patient- and hospital-level characteristics and two ED performance measures: length of stay in the ED of more than 6 hours and 90-day mortality.

MEASUREMENTS AND MAIN RESULTS

From April 2007 to March 2012, 261,274 adults presented to 118 EDs in Ontario, generating 314,836 ICU admissions. This activity represented 4.1% of all adult ED visits (incidence, 1,374 ICU admissions/100,000 ED visits). Median (interquartile range) ED length of stay was 7 (4-13) hours. Less than half (41.4%; 95% confidence interval [CI], 41.2-41.5) of these patients had an ED length of stay of 6 hours or less, whereas 10.5% (95% CI, 10.4-10.6) stayed 24 hours or longer. Hospital characteristics associated with ED length of stay more than 6 hours included shift-level ED crowding (mean length of stay of patients of similar acuity registering during same 8 h epoch) (odds ratio [OR], 1.19/h; 95% CI, 1.19-1.19), ED annual visit volume (OR, 1.01/1,000 patients; 95% CI, 1.01-1.01), time of ED presentation (00:00-07:59) (OR, 1.41; 95% CI, 1.38-1.45), and ICU functioning at greater than 20% above the average annual census (OR, 1.10; 95% CI, 1.08-1.12). ED length of stay more than 6 hours was not associated with 90-day mortality after adjustment for selected confounders (OR, 0.99; 95% CI, 0.97-1.02).

CONCLUSIONS

In this population-based study, less than half of adult ED patients were admitted to an ICU 6 hours or less after arrival to an ED, an internationally recognized performance indicator for ED care quality. ED and ICU strain generated by time-varying demand on capacity was an important determinant of ED length of stay. However, prolonged length of stay in an ED did not measurably reduce 90-day mortality.

Duration of Mechanical Ventilation in the Emergency Department

INTRODUCTION

Due to hospital crowding, mechanically ventilated patients are increasingly spending hours boarding in emergency departments (ED) before intensive care unit (ICU) admission. This study aims to evaluate the association between time ventilated in the ED and in-hospital mortality, duration of mechanical ventilation, ICU and hospital length of stay (LOS).

METHODS

This was a multi-center, prospective, observational study of patients ventilated in the ED, conducted at three academic Level I Trauma Centers from July 2011 to March 2013. All consecutive adult patients on invasive mechanical ventilation were eligible for enrollment. We performed a Cox regression to assess for a mortality effect for mechanically ventilated patients with each hour of increasing LOS in the ED and multivariable regression analyses to assess for independently significant contributors to in-hospital mortality. Our primary outcome was in-hospital mortality, with secondary outcomes of ventilator days, ICU LOS and hospital LOS. We further commented on use of lung protective ventilation and frequency of ventilator changes made in this cohort.

RESULTS

We enrolled 535 patients, of whom 525 met all inclusion criteria. Altered mental status without respiratory pathology was the most common reason for intubation, followed by trauma and respiratory failure. Using iterated Cox regression, a mortality effect occurred at ED time of mechanical ventilation > 7 hours, and the longer ED stay was also associated with a longer total duration of intubation. However, adjusted multivariable regression analysis demonstrated only older age and admission to the neurosciences ICU as independently associated with increased mortality. Of interest, only 23.8% of patients ventilated in the ED for over seven hours had changes made to their ventilator.

CONCLUSION

In a prospective observational study of patients mechanically ventilated in the ED, there was a significant mortality benefit to expedited transfer of patients into an appropriate ICU setting.

Analgosedation Practices and the Impact of Sedation Depth on Clinical Outcomes Among Patients Requiring Mechanical Ventilation in the ED: A Cohort Study

BACKGROUND

Analgesia and sedation are cornerstone therapies for mechanically ventilated patients. Despite data showing that early deep sedation in the ICU influences outcome, this has not been investigated in the ED. Therefore, ED-based sedation practices, and their influence on outcome, remain incompletely defined. This study's objectives were to describe ED sedation practices in mechanically ventilated patients and to test the hypothesis that ED sedation depth is associated with worse outcomes.

METHODS

This was a cohort study of a prospectively compiled ED registry of adult mechanically ventilated patients at a single academic medical center. Hospital mortality was the primary outcome and hospital-, ICU-, and ventilator-free days were secondary outcomes. A backward stepwise multivariable logistic regression model evaluated the primary outcome as a function of ED sedation depth. Sedation depth was assessed with the Richmond Agitation-Sedation Scale (RASS).

RESULTS

Four hundred fourteen patients were studied. In the ED, 354 patients (85.5%) received fentanyl, 254 (61.3%) received midazolam, and 194 (46.9%) received propofol. Deep sedation was observed in 244 patients (64.0%). After adjusting for confounders, a deeper ED RASS was associated with mortality (adjusted OR, 0.77; 95% CI, 0.63-0.94).

CONCLUSIONS

Early deep sedation is common in mechanically ventilated ED patients and is associated with worse mortality. These data suggest that ED-based sedation is a modifiable variable that could be targeted to improve outcome.

A Quasi-Experimental, Before-After Trial Examining the Impact of an Emergency Department Mechanical Ventilator Protocol on Clinical Outcomes and Lung-Protective Ventilation in Acute Respiratory Distress Syndrome

OBJECTIVES

To evaluate the impact of an emergency department mechanical ventilation protocol on clinical outcomes and adherence to lung-protective ventilation in patients with acute respiratory distress syndrome.

DESIGN

Quasi-experimental, before-after trial.

SETTING

Emergency department and ICUs of an academic center.

PATIENTS

Mechanically ventilated emergency department patients experiencing acute respiratory distress syndrome while in the emergency department or after admission to the ICU.

INTERVENTIONS

An emergency department ventilator protocol which targeted variables in need of quality improvement, as identified by prior work: 1) lung-protective tidal volume, 2) appropriate setting of positive end-expiratory pressure, 3) oxygen weaning, and 4) head-of-bed elevation.

MEASUREMENTS AND MAIN RESULTS

A total of 229 patients (186 preintervention group, 43 intervention group) were studied. In the emergency department, the intervention was associated with significant changes (p < 0.01 for all) in tidal volume, positive end-expiratory pressure, respiratory rate, oxygen administration, and head-of-bed elevation. There was a reduction in emergency department tidal volume from 8.1 mL/kg predicted body weight (7.0-9.1) to 6.4 mL/kg predicted body weight (6.1-6.7) and an increase in lung-protective ventilation from 11.1% to 61.5%, p value of less than 0.01. The intervention was associated with a reduction in mortality from 54.8% to 39.5% (odds ratio, 0.38; 95% CI, 0.17-0.83; p = 0.02) and a 3.9 day increase in ventilator-free days, p value equals to 0.01.

CONCLUSIONS

This before-after study of mechanically ventilated patients with acute respiratory distress syndrome demonstrates that implementing a mechanical ventilator protocol in the emergency department is feasible and associated with improved clinical outcomes.

Protective lung strategies: A cross sectional survey of nurses knowledge and use in the emergency department

BACKGROUND

Mechanical ventilation (MV) is commonly used in emergency departments (EDs). Protective lung strategies (PLS), comprising of low tidal volume (6mL/kg), control of oxygen and plateau pressures, and administration of positive end expiratory pressure (PEEP) has been shown to reduces the risks associated with MV but there is little evidence exists about nurses' knowledge or application of PLS. Our aim was to explore nurses knowledge and application of PLS in Australian EDs.

METHODS

Descriptive, exploratory design utilising an online questionnaire. A convenience sample was recruited via the College of Emergency Nursing Australasia mailing list and secondary snowball sampling was used to optimise response rate.

RESULTS

There were 157 participants. PLS are being used in most EDs (n=104, 75%) and clinical practice guidelines (CPG) are often available (n=86, 62%). Most ED ventilators are capable of implementing PLS, but measurement of plateau pressures was infrequent (n=46%). Participants demonstrate appropriate knowledge, but reported varying levels of confidence and perceived autonomy when implementing PLS in the ED.

CONCLUSION

PLS are being used in Australian EDs, aligning with best available evidence. Nursing staff have good levels of PLS knowledge. Development of an evidence-based CPG may improve confidence when implementing PLS and may pave the way for ED nurses to expand their scope of practice.

Lung-Protective Ventilation Initiated in the Emergency Department (LOV-ED): A Quasi-Experimental, Before-After Trial

STUDY OBJECTIVE

We evaluated the efficacy of an emergency department (ED)-based lung-protective mechanical ventilation protocol for the prevention of pulmonary complications.

METHODS

This was a quasi-experimental, before-after study that consisted of a preintervention period, a run-in period of approximately 6 months, and a prospective intervention period. The intervention was a multifaceted ED-based mechanical ventilator protocol targeting lung-protective tidal volume, appropriate setting of positive end-expiratory pressure, rapid oxygen weaning, and head-of-bed elevation. A propensity score-matched analysis was used to evaluate the primary outcome, which was the composite incidence of acute respiratory distress syndrome and ventilator-associated conditions.

RESULTS

A total of 1,192 patients in the preintervention group and 513 patients in the intervention group were included. Lung-protective ventilation increased by 48.4% in the intervention group. In the propensity score-matched analysis (n=490 in each group), the primary outcome occurred in 71 patients (14.5%) in the preintervention group compared with 36 patients (7.4%) in the intervention group (adjusted odds ratio 0.47; 95% confidence interval [CI] 0.31 to 0.71). There was an increase in ventilator-free days (mean difference 3.7; 95% CI 2.3 to 5.1), ICU-free days (mean difference 2.4; 95% CI 1.0 to 3.7), and hospital-free days (mean difference 2.4; 95% CI 1.2 to 3.6) associated with the intervention. The mortality rate was 34.1% in the preintervention group and 19.6% in the intervention group (adjusted odds ratio 0.47; 95% CI 0.35 to 0.63).

CONCLUSION

Implementing a mechanical ventilator protocol in the ED is feasible and is associated with significant improvements in the delivery of safe mechanical ventilation and clinical outcome.

Early risk factors and the role of fluid administration in developing acute respiratory distress syndrome in septic patients

Background

Sepsis is a major risk factor for acute respiratory distress syndrome (ARDS). However, there remains a paucity of literature examining risk factors for ARDS in septic patients early in their course. This study examined the role of early fluid administration and identified other risk factors within the first 6 h of hospital presentation associated with developing ARDS in septic patients.

Methods

This was a secondary analysis of septic adult patients presenting to the Emergency Department or being admitted for high-risk elective surgery from the multicenter observational cohort study, US Critical Injury and Illness trial Group-Lung Injury Prevention Study 1 (USCIITG-LIPS 1, NCT00889772). Multivariable logistic regression was performed to identify potential early risk factors for ARDS. Stratified analysis by shock status was performed to examine the association between early fluid administration and ARDS.

Results

Of the 5584 patients in the original study cohort, 2534 (45.4%) met our criteria for sepsis. One hundred and fifty-six (6.2%) of these patients developed ARDS during the hospital stay. In multivariable analyses, Acute Physiology and Chronic Health Evaluation (APACHE) II score (OR 1.10, 95% CI 1.07–1.13), age (OR 0.97, 95% CI 0.96–0.98), total fluid infused in the first 6 h (in liters) (OR 1.15, 95% CI 1.03–1.29), shock (OR 2.57, 95% CI 1.62–4.08), pneumonia as a site of infection (OR 2.31, 95% CI 1.59–3.36), pancreatitis (OR 3.86, 95% CI 1.33–11.24), and acute abdomen (OR 3.77, 95% CI 1.37–10.41) were associated with developing ARDS. In the stratified analysis, total fluid infused in the first 6 h (in liters) (OR 1.05, 95% CI 0.87–1.28) was not associated with the development of ARDS in the shock group, while there was an association in the non-shock group (OR 1.21, 95% CI 1.05–1.38).

Conclusions

In septic patients, the following risk factors identified within the first 6 h of hospital presentation were associated with ARDS: APACHE II score, presence of shock, pulmonary source of infection, pancreatitis, and presence of an acute abdomen. In septic patients without shock, the amount of fluid infused during the first 6 h of hospital presentation was associated with developing ARDS.

Electronic supplementary material

The online version of this article (doi:10.1186/s13613-017-0233-1) contains supplementary material, which is available to authorized users.

Early intervention of patients at risk for acute respiratory failure and prolonged mechanical ventilation with a checklist aimed at the prevention of organ failure: protocol for a pragmatic stepped-wedged cluster trial of PROOFCheck

INTRODUCTION

Acute respiratory failure (ARF) often presents and progresses outside of the intensive care unit. However, recognition and treatment of acute critical illness is often delayed with inconsistent adherence to evidence-based care known to decrease the duration of mechanical ventilation (MV) and complications of critical illness. The goal of this trial is to determine whether the implementation of an electronic medical record-based early alert for progressive respiratory failure coupled with a checklist to promote early compliance to best practice in respiratory failure can improve the outcomes of patients at risk for prolonged respiratory failure and death.

METHODS AND ANALYSIS

A pragmatic stepped-wedged cluster clinical trial involving 6 hospitals is planned. The study will include adult hospitalised patients identified as high risk for MV >48 hours or death because they were mechanically ventilated outside of the operating room or they were identified as high risk for ARF on the Accurate Prediction of PROlonged VEntilation (APPROVE) score. Patients with advanced directives limiting intubation will be excluded. The intervention will consist of (1) automated identification and notification of clinician of high-risk patients by APPROVE or by invasive MV and (2) checklist of evidence-based practices in ARF (Prevention of Organ Failure Checklist-PROOFCheck). APPROVE and PROOFCheck will be developed in the pretrial period. Primary outcome is hospital mortality. Secondary outcomes include length of stay, ventilator and organ failure-free days and 6-month and 12-month mortality. Predefined subgroup analysis of patients with limitation of aggressive care after study entry is planned. Generalised estimating equations will be used to compare patients in the intervention phase with the control phase, adjusting for clustering within hospitals and time.

ETHICS AND DISSEMINATION

The study was approved by the institutional review boards. Results will be published in peer-reviewed journals and presented at international meetings.

TRIAL REGISTRATION NUMBER

NCT02488174.

Academic Emergency Medicine Physicians' Knowledge of Mechanical Ventilation

Introduction

Although emergency physicians frequently intubate patients, management of mechanical ventilation has not been emphasized in emergency medicine (EM) education or clinical practice. The objective of this study was to quantify EM attendings’ education, experience, and knowledge regarding mechanical ventilation in the emergency department.

Methods

We developed a survey of academic EM attendings’ educational experiences with ventilators and a knowledge assessment tool with nine clinical questions. EM attendings at key teaching hospitals for seven EM residency training programs in the northeastern United States were invited to participate in this survey study. We performed correlation and regression analyses to evaluate the relationship between attendings’ scores on the assessment instrument and their training, education, and comfort with ventilation.

Results

Of 394 EM attendings surveyed, 211 responded (53.6%). Of respondents, 74.5% reported receiving three or fewer hours of ventilation-related education from EM sources over the past year and 98 (46%) reported receiving between 0–1 hour of education. The overall correct response rate for the assessment tool was 73.4%, with a standard deviation of 19.9. The factors associated with a higher score were completion of an EM residency, prior emphasis on mechanical ventilation during one’s own residency, working in a setting where an emergency physician bears primary responsibility for ventilator management, and level of comfort with managing ventilated patients. Physicians’ comfort was associated with the frequency of ventilator changes and EM management of ventilation, as well as hours of education.

Conclusion

EM attendings report caring for mechanically ventilated patients frequently, but most receive fewer than three educational hours a year on mechanical ventilation, and nearly half receive 0–1 hour. Physicians’ performance on an assessment tool for mechanical ventilation is most strongly correlated with their self-reported comfort with mechanical ventilation.

Initial mechanical ventilator settings and lung protective ventilation in the ED

OBJECTIVE

Mechanical ventilation with low tidal volumes has been shown to improve outcomes for patients both with and without acute respiratory distress syndrome. This study aims to characterize mechanically ventilated patients in the emergency department (ED), describe the initial ED ventilator settings, and assess for associations between lung protective ventilation strategies in the ED and outcomes.

METHODS

This was a multicenter, prospective, observational study of mechanical ventilation at 3 academic EDs. We defined lung protective ventilation as a tidal volume of less than or equal to 8 mL/kg of predicted body weight and compared outcomes for patients ventilated with lung protective vs non-lung protective ventilation, including inhospital mortality, ventilator days, intensive care unit length of stay, and hospital length of stay.

RESULTS

Data from 433 patients were analyzed. Altered mental status without respiratory pathology was the most common reason for intubation, followed by trauma and respiratory failure. Two hundred sixty-one patients (60.3%) received lung protective ventilation, but most patients were ventilated with a low positive end-expiratory pressure, high fraction of inspired oxygen strategy. Patients were ventilated in the ED for a mean of 5 hours and 7 minutes but had few ventilator adjustments. Outcomes were not significantly different between patients receiving lung protective vs non-lung protective ventilation.

CONCLUSIONS

Nearly 40% of ED patients were ventilated with non-lung protective ventilation as well as with low positive end-expiratory pressure and high fraction of inspired oxygen. Despite a mean ED ventilation time of more than 5 hours, few patients had adjustments made to their ventilators.

Lung-protective ventilation initiated in the emergency department (LOV-ED): a study protocol for a quasi-experimental, before-after trial aimed at reducing pulmonary complications

INTRODUCTION

In critically ill patients, acute respiratory distress syndrome (ARDS) and ventilator-associated conditions (VACs) are associated with increased mortality, survivor morbidity and healthcare resource utilisation. Studies conclusively demonstrate that initial ventilator settings in patients with ARDS, and at risk for it, impact outcome. No studies have been conducted in the emergency department (ED) to determine if lung-protective ventilation in patients at risk for ARDS can reduce its incidence. Since the ED is the entry point to the intensive care unit for hundreds of thousands of mechanically ventilated patients annually in the USA, this represents a knowledge gap in this arena. A lung-protective ventilation strategy was instituted in our ED in 2014. It aims to address the parameters in need of quality improvement, as demonstrated by our previous research: (1) prevention of volutrauma; (2) appropriate positive end-expiratory pressure setting; (3) prevention of hyperoxia; and (4) aspiration precautions.

METHODS AND ANALYSIS

The lung-protective ventilation initiated in the emergency department (LOV-ED) trial is a single-centre, quasi-experimental before-after study testing the hypothesis that lung-protective ventilation, initiated in the ED, is associated with reduced pulmonary complications. An intervention cohort of 513 mechanically ventilated adult ED patients will be compared with over 1000 preintervention control patients. The primary outcome is a composite outcome of pulmonary complications after admission (ARDS and VACs). Multivariable logistic regression with propensity score adjustment will test the hypothesis that ED lung-protective ventilation decreases the incidence of pulmonary complications.

ETHICS AND DISSEMINATION

Approval of the study was obtained prior to data collection on the first patient. As the study is a before-after observational study, examining the effect of treatment changes over time, it is being conducted with waiver of informed consent. This work will be disseminated by publication of full-length manuscripts, presentation in abstract form at major scientific meetings and data sharing with other investigators through academically established means.

TRIAL REGISTRATION NUMBER

NCT02543554.

Sepsis-associated pulmonary complications in emergency department patients monitored with serial lactate: An observational cohort study

PURPOSE

Patients with severe sepsis and septic shock are at high risk for development of pulmonary complications, including acute respiratory distress syndrome (ARDS). Serial lactate monitoring is a useful tool to gauge global tissue hypoxia in emergency department (ED) patients with sepsis. We hypothesized that patients undergoing serial lactate monitoring (SL) would demonstrate a decreased incidence of pulmonary complications.

METHODS

This is a retrospective observational cohort study of adult severe sepsis and septic shock patients with elevated lactate presenting to a large academic ED. A total of 243 patients were assigned to SL (n=132) or no serial lactate monitoring (NL; n=111). The primary outcome was a composite of pulmonary complications: (1) ARDS development and (2) respiratory failure.

RESULTS

Twenty-eight patients (21%) in the SL group and 37 patients (33%) in the NL group developed the primary outcome (P=.03). Multivariate analysis demonstrated an association between the NL group and development of pulmonary complications (adjusted odds ratio [aOR], 2.1; confidence interval [CI], 1.15-3.78). Emergency department mechanical ventilation was independently associated with development of ARDS (aOR, 3.5; 1.8-7.0). In the a priori subgroup of patients mechanically ventilated in the ED (n=97), those who developed ARDS received higher tidal volumes compared to patients who did not develop ARDS (8.7 mL/kg predicted body weight [interquartile range, 7.6-9.5] vs 7.6 [interquartile range, 6.8-9.0]; P<.01).

CONCLUSIONS

Serial lactate monitoring is associated with a decrease in major pulmonary complications in severe sepsis and septic shock. Acute respiratory distress syndrome incidence is also influenced by ED-based mechanical ventilation. These results provide 2 potentially modifiable variables to be targeted in future studies to prevent pulmonary complications in this patient subset.

Risk factors for mortality despite early protocolized resuscitation for severe sepsis and septic shock in the emergency department

PURPOSE

The purpose was to identify risk factors associated with in-hospital mortality among emergency department (ED) patients with severe sepsis and septic shock managed with early protocolized resuscitation.

METHODS

This was a retrospective, observational cohort study in an academic, tertiary care ED. We enrolled 411 adult patients with severe sepsis and lactate ≥4.0 mmol/L (n = 203) or septic shock (n = 208) who received protocolized resuscitation from 2005 to 2009. Emergency department variables, microbial cultures, and in-hospital outcomes were obtained from the medical record. Multivariable regression was used to identify factors independently associated with in-hospital mortality.

RESULTS

Mean age was 59.5 ± 16.3 years; 57% were male. Mean lactate was 4.8 mmol/L (3.5-6.7), 54% had positive cultures, and 27% received vasopressors in the ED. One hundred and five (26%) patients died in-hospital. Age, active cancer, do-not-resuscitate status on ED arrival, lack of fever, hypoglycemia, and intubation were independently associated with increased in-hospital mortality. Lactate clearance and diabetes were associated with a decreased risk of in-hospital death.

CONCLUSIONS

We identified a number of factors that were associated with in-hospital mortality among ED patients with severe sepsis or septic shock despite treatment with early protocolized resuscitation. These findings provide insights into aspects of early sepsis care that can be targets for future intervention.

Invasive Mechanical Ventilation in California Over 2000-2009: Implications for Emergency Medicine

INTRODUCTION

Patients who require invasive mechanical ventilation (IMV) often represent a sequence of care between the emergency department (ED) and intensive care unit (ICU). Despite being the most populous state, little information exists to define patterns of IMV use within the state of California.

METHODS

We examined data from the masked Patient Discharge Database of California's Office of Statewide Health Planning and Development from 2000-2009. Adult patients who received IMV during their stay were identified using the International Classification of Diseases 9th Revision and Clinical Modification procedure codes (96.70, 96.71, 96.72). Patients were divided into age strata (18-34 yr, 35-64 yr, and >65 yr). Using descriptive statistics and regression analyses, for IMV discharges during the study period, we quantified the number of ED vs. non-ED based admissions; changes in patient characteristics and clinical outcome; evaluated the marginal costs for IMV; determined predictors for prolonged acute mechanical ventilation (PAMV, i.e. IMV>96 hr); and projected the number of IMV discharges and ED-based admissions by year 2020.

RESULTS

There were 696,634 IMV discharges available for analysis. From 2000-2009, IMV discharges increased by 2.8%/year: n=60,933 (293/100,000 persons) in 2000 to n=79,868 (328/100,000 persons) in 2009. While ED-based admissions grew by 3.8%/year, non-ED-based admissions remained stable (0%). During 2000-2009, fastest growth was noted for 1) the 35-64 year age strata; 2) Hispanics; 3) patients with non-Medicare public insurance; and 4) patients requiring PAMV. Average total patient cost-adjusted charges per hospital discharge increased by 29% from 2000 (from $42,528 to $60,215 in 2014 dollars) along with increases in the number of patients discharged to home and skilled nursing facilities. Higher marginal costs were noted for younger patients (ages 18-34 yr), non-whites, and publicly insured patients. Some of the strongest predictors for PAMV were age 35-64 years (OR=1.12; 95% CI [1.09-1.14], p<0.05); non-Whites; and non-Medicare public insurance. Our models suggest that by 2020, IMV discharges will grow to n=153,153 (377 IMV discharges/100,000 persons) with 99,095 admitted through the ED.

CONCLUSION

Based on sustained growth over the past decade, by the year 2020, we project a further increase to 153,153 IMV discharges with 99,095 admitted through the ED. Given limited ICU bed capacities, ongoing increases in the number and type of IMV patients have the potential to adversely affect California EDs that often admit patients to ICUs.

The impact of serial lactate monitoring on emergency department resuscitation interventions and clinical outcomes in severe sepsis and septic shock: an observational cohort study

Monitoring in the setting of critical illness must be linked to beneficial therapy to affect clinical outcome. Elevated serum lactate is associated with an increase in mortality in emergency department (ED) patients with severe sepsis and septic shock. The reduction of lactate levels toward normal during acute resuscitation is associated with improved clinical outcomes. The majority of data demonstrating the interventions used to achieve a reduction in lactate levels and the associated clinical outcomes have been obtained during protocolized randomized trials. We therefore conducted a retrospective observational cohort study of 243 adult patients with severe sepsis and septic shock to assess the interventions associated with nonprotocolized serial lactate monitoring and to assess clinical outcomes. A multivariable model was used to assess outcome differences between the serial lactate (SL) and no serial lactate (NL) cohorts. The SL group received more crystalloid resuscitation (3.6 L vs. 2.5 L; P < 0.01), central venous oxygen saturation monitoring (30% vs. 12%; P < 0.01), and central venous pressure monitoring (23.5% vs. 11.8%; P = 0.02). By day 28, a total of 31 patients in the SL group (23.5%) and 44 in the NL group (39.6%) had died. Multivariable logistic regression analysis demonstrated that the lack of serial lactate monitoring was independently associated with mortality (adjusted odds ratio, 2.09; 95% confidence interval [CI], 1.12 - 3.89; P = 0.02). The SL group also showed greater improvement in 24-h Sequential Organ Failure Assessment scores (1.16 vs. 0.19; P = 0.03), decreased intensive care unit length of stay in days (4.6 vs. 6.0; P = 0.04), and more ventilator-free (19.9 vs. 16; P = 0.05) and vasopressor-free (21.6 vs. 17.9; P = 0.02) days. In the setting of routine clinical care, serial lactate monitoring is associated with an increase in crystalloid administration, resuscitation interventions, and improved clinical outcomes in ED patients with severe sepsis and septic shock. This suggests that serial lactate monitoring, targeting a reduction in lactate levels to normal, is a generalizable resuscitation target in the ED.