The use of inhaled prostaglandins in patients with ARDS: a systematic review and meta-analysis

OBJECTIVE

This study aimed to determine whether inhaled prostaglandins are associated with improvement in pulmonary physiology or mortality in patients with ARDS and assess adverse effects.

METHODS

The following data sources were used: PubMed, EMBASE, CINAHL, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, reference lists, conference proceedings, and ClinicalTrials.gov. Studies selected included randomized controlled trials and nonrandomized studies. For data extraction, two reviewers independently screened titles and abstracts for eligibility. With regard to data synthesis, 25 studies (two RCTs) published over 21 years (1993-2014) were included. The PROSPERO registration number was CRD42014013180.

RESULTS

One randomized controlled trial showed no difference in the change in mean Pao2 to Fio2 ratio when comparing inhaled alprostadil to placebo: 141.2 (95% CI, 120.8-161.5) to 161.5 (95% CI, 134.6-188.3) vs 163.4 (95% CI, 140.8-186.0) to 186.8 (95% CI, 162.9-210.7), P = .21. Meta-analysis of the remaining studies demonstrated that inhaled prostaglandins were associated with improvement in Pao2 to Fio2 ratio (16 studies; 39.0% higher; 95% CI, 26.7%-51.3%), and Pao2 (eight studies; 21.4% higher; 95% CI, 12.2%-30.6%), and a decrease in pulmonary artery pressure (-4.8 mm Hg; 95% CI, -6.8 mm Hg to -2.8 mm Hg). Risk of bias and heterogeneity were high. Meta-regression found no association with publication year (P = .862), baseline oxygenation (P = .106), and ARDS etiology (P = .816) with the treatment effect. Hypotension occurred in 17.4% of patients in observational studies.

CONCLUSIONS

In ARDS, inhaled prostaglandins improve oxygenation and decrease pulmonary artery pressures and may be associated with harm. Data are limited both in terms of methodologic quality and demonstration of clinical benefit. The use of inhaled prostaglandins in ARDS needs further study.

Achieving regionalization through rural interhospital transfer

Regionalization of emergency medical care aims to provide consistent and efficient high-quality care leading to optimal clinical outcomes by matching patient needs with appropriate resources at a network of hospitals. Regionalized care has been shown to improve outcomes in trauma, myocardial infarction, stroke, cardiac arrest, and acute respiratory distress syndrome. In rural areas, effective regionalization often requires interhospital transfer. The decision to transfer is complex and includes such factors as capabilities of the presenting hospital; capacity at the receiving hospital; and financial, geographic, and patient-preference considerations. Although transfer to a comprehensive center has proven benefits for some conditions, the transfer process is not without risk. These risks include clinical deterioration, limited resource availability during transport, vehicular crashes, time delays for time-sensitive care, poor communication between providers, and neglect of patient preferences. This article reviews the transfer decision, financial implications, risks, and considerations for patients undergoing rural interhospital transfer. We identify several strategies that should be considered for development of the regionalized emergency health care system of the future and identify areas where further research is necessary.

Prehospital oral chlorhexidine does not reduce the rate of ventilator-associated pneumonia among critically ill trauma patients: A prospective concurrent-control study

PURPOSE

The purpose of the study was to test the hypothesis that prehospital oral chlorhexidine administered to intubated trauma patients will decrease the Clinical Pulmonary Infection Score (CPIS) during the first 2 days of hospitalization.

MATERIALS AND METHODS

Prospective interventional concurrent-control study of all intubated adult trauma patients transported by air ambulance to a 711-bed Midwestern academic trauma center over a 1-year period. Patients transported by 2 university-based helicopters were treated with oral chlorhexidine after intubation, and the control group was patients transported by other air transport services.

RESULTS

Sixty-seven patients were enrolled, of which 23 received chlorhexidine (9 patients allocated to the intervention were not treated). The change in CPIS score was no different between the intervention and control groups by intention to treat (1.06- vs 1.40-point reduction, P = .520), and no difference was observed in tracheal colonization (29.0% vs 36.7%, P = .586). No differences were observed in the rate of clinical pneumonia (8.7% vs 8.6%, P = .987) or mortality (P = .196) in the per-protocol chlorhexidine group.

CONCLUSIONS

The prehospital administration of oral chlorhexidine does not reduce the CPIS score over the first 48 hours of admission for intubated trauma patients. Further study should explore other prehospital strategies of reducing complications of critical illness.

Prehospital tidal volume influences hospital tidal volume: A cohort study

PURPOSE

The purposes of the study are to describe current practice of ventilation in a modern air medical system and to measure the association of ventilation strategy with subsequent ventilator care and acute respiratory distress syndrome (ARDS).

MATERIALS AND METHODS

Retrospective observational cohort study of intubated adult patients (n = 235) transported by a university-affiliated air medical transport service to a 711-bed tertiary academic center between July 2011 and May 2013. Low tidal volume ventilation was defined as tidal volumes less than or equal to 8 mL/kg predicted body weight. Multivariable regression was used to measure the association between prehospital tidal volume, hospital ventilation strategy, and ARDS.

RESULTS

Most patients (57%) were ventilated solely with bag valve ventilation during transport. Mean tidal volume of mechanically ventilated patients was 8.6 mL/kg predicted body weight (SD, 0.2 mL/kg). Low tidal volume ventilation was used in 13% of patients. Patients receiving low tidal volume ventilation during air medical transport were more likely to receive low tidal volume ventilation in the emergency department (P < .001) and intensive care unit (P = .015). Acute respiratory distress syndrome was not associated with prehospital tidal volume (P = .840).

CONCLUSIONS

Low tidal volume ventilation was rare during air medical transport. Air transport ventilation strategy influenced subsequent ventilation but was not associated with ARDS.

The impact of cardiac dysfunction on acute respiratory distress syndrome and mortality in mechanically ventilated patients with severe sepsis and septic shock: an observational study

PURPOSE

Acute respiratory distress syndrome (ARDS) is associated with significant mortality and morbidity in survivors. Treatment is only supportive, therefore elucidating modifiable factors that could prevent ARDS could have a profound impact on outcome. The impact that sepsis-associated cardiac dysfunction has on ARDS is not known.

MATERIALS AND METHODS

In this retrospective observational cohort study of mechanically ventilated patients with severe sepsis and septic shock, 122 patients were assessed for the impact of sepsis-associated cardiac dysfunction on incidence of ARDS (primary outcome) and mortality.

RESULTS

Sepsis-associated cardiac dysfunction occurred in 44 patients (36.1%). There was no association of sepsis-associated cardiac dysfunction with ARDS incidence (p= 0.59) or mortality, and no association with outcomes in patients that did progress to ARDS after admission. Multivariable logistic regression demonstrated that higher BMI was associated with progression to ARDS (adjusted OR 11.84, 95% CI 1.24 to 113.0, p= 0.02).

CONCLUSIONS

Cardiac dysfunction in mechanically ventilated patients with sepsis did not impact ARDS incidence, clinical outcome in ARDS patients, or mortality. This contrasts against previous investigations demonstrating an influence of nonpulmonary organ dysfunction on outcome in ARDS. Given the frequency of ARDS as a sequela of sepsis, the impact of cardiac dysfunction on outcome should be further studied.

Reducing the burden of acute respiratory distress syndrome: the case for early intervention and the potential role of the emergency department

The mortality for acute respiratory distress syndrome (ARDS) remains unacceptably high. Success in clinical trials has been limited, resulting in a lack of effective therapies to treat the syndrome. The projected increase in mechanically ventilated patients and global need for critical care services suggests that the clinical and research landscape in ARDS can no longer be confined to the intensive care unit. A demonstrable minority of patients present to the emergency department (ED) with ARDS, and ARDS onset typically occurs shortly after intensive care unit admission. Furthermore, the ED is an entry point for many of the highest-risk patients for ARDS development and progression. These facts, combined with prolonged lengths of stay in the ED, suggest that the ED could represent a window of opportunity for treatment and preventive strategies, as well as clinical trial enrollment. This review aims to discuss some of the potential strategies that may prevent or alter the trajectory of ARDS, with a focus on the potential role the ED could play in reducing the burden of this syndrome.

Duration of prehospital intubation is not a risk factor for development of early ventilator-associated pneumonia

PURPOSE

Ventilator-associated pneumonia (VAP) is a significant cause of morbidity and mortality among critically ill patients with trauma. Few VAP prevention strategies have been studied in the prehospital environment. The objectives of this study are to measure the association between duration of prehospital intubation and intubation location with subsequent incidence of early (within 5 days) VAP.

MATERIALS AND METHODS

Single-center retrospective cohort study of all intubated adult (age≥18 years) patients with trauma presenting to a 711-bed Midwestern Level I trauma center between January 2005 and December 2011 (n=860).

RESULTS

Thirty-five patients (6.4%) were diagnosed as having early VAP during the study period. Using multivariable logistic regression to adjust for age, injury severity score, and year (corresponding to VAP bundle implementation), the duration of intubation prior to hospital admission was not associated with subsequent diagnosis of VAP (adjusted odds ratio, 0.90 per hour; 95% confidence interval, 0.70-1.15). Location of intubation was similarly not associated with VAP.

CONCLUSIONS

Duration of prehospital intubation and intubation location were not different in patients with trauma who developed early VAP. Further prospective analyses should be conducted to better elucidate the effect of prehospital management on the development of traditionally in-hospital complications.

Characterizing critical care physician staffing in rural America: a description of Iowa intensive care unit staffing

PURPOSE

This study aimed to characterize intensive care unit (ICU) physician staffing patterns in a predominantly rural state.

MATERIALS AND METHODS

A prospective telephone survey of ICU nurse managers in all Iowa hospitals with an ICU was conducted.

RESULTS

Of 122 Iowa hospitals, 64 ICUs in 58 (48%) hospitals were identified, and 46 (72%) responded to the survey. Most ICUs (96%) used an open admission model and cared for undifferentiated medical and surgical patients (88%), and only 27% of open ICUs required critical care or pulmonary consultation for admitted patients. Most (59%) Iowa ICUs had a critical care physician or pulmonologist available, and high-intensity staffing was practiced in 30% of ICUs. Most physicians identified as practicing critical care (63%) were not board certified in critical care. Critical care physicians were available in a minority of hospitals routinely for inpatient intubation and cardiac arrest management (29% and 10%, respectively), and emergency physicians and other practitioners commonly responded to emergencies throughout the hospital.

CONCLUSIONS

Many Iowa hospitals have ICUs, and staffing patterns in Iowa ICUs mirror closely national staffing practices. Most ICUs are multispecialty, open ICUs in community hospitals. These factors should inform training and resource allocation for intensivists in rural states.

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

OBJECTIVES

The objectives were to characterize the use of mechanical ventilation in the emergency department (ED), with respect to ventilator settings, monitoring, and titration and to determine the incidence of progression to acute lung injury (ALI) after admission, examining the influence of factors present in the ED on ALI progression.

METHODS

This was a retrospective, observational cohort study of mechanically ventilated patients with severe sepsis and septic shock (June 2005 to May 2010), presenting to an academic ED with an annual census of >95,000 patients. All patients in the study (n = 251) were analyzed for characterization of mechanical ventilation use in the ED. The primary outcome variable of interest was the incidence of ALI progression after intensive care unit (ICU) admission from the ED and risk factors present in the ED associated with this outcome. Secondary analyses included ALI present in the ED and clinical outcomes comparing all patients progressing to ALI versus no ALI. To assess predictors of progression to ALI, significant variables in univariable analyses at a p ≤ 0.10 level were candidates for inclusion in a bidirectional, stepwise, multivariable logistic regression analysis.

RESULTS

Lung-protective ventilation was used in 68 patients (27.1%) and did not differ based on ALI status. Delivered tidal volume was highly variable, with a median tidal volume delivered of 8.8 mL/kg ideal body weight (IBW; interquartile range [IQR] = 7.8 to 10.0) and a range of 5.2 to 14.6 mL/kg IBW. Sixty-nine patients (27.5%) in the entire cohort progressed to ALI after admission to the hospital, with a mean (±SD) onset of 2.1 (±1) days. Multivariable logistic regression analysis demonstrated that a higher body mass index (BMI), higher Sequential Organ Failure Assessment (SOFA) score, and ED vasopressor use were associated with progression to ALI. There was no association between ED ventilator settings and progression to ALI. Compared to patients who did not progress to ALI, patients progressing to ALI after admission from the ED had an increase in mechanical ventilator duration, vasopressor dependence, and hospital length of stay (LOS).

CONCLUSIONS

Lung-protective ventilation is uncommon in the ED, regardless of ALI status. Given the frequency of ALI in the ED, the progression shortly after ICU admission, and the clinical consequences of this syndrome, the effect of ED-based interventions aimed at reducing the sequelae of ALI should be investigated further.

Lower tidal volume at initiation of mechanical ventilation may reduce progression to acute respiratory distress syndrome: a systematic review

INTRODUCTION

The most appropriate tidal volume in patients without acute respiratory distress syndrome (ARDS) is controversial and has not been rigorously examined. Our objective was to determine whether a mechanical ventilation strategy using lower tidal volume is associated with a decreased incidence of progression to ARDS when compared with a higher tidal volume strategy.

METHODS

A systematic search of MEDLINE, EMBASE, CINAHL, the Cochrane Library, conference proceedings, and clinical trial registration was performed with a comprehensive strategy. Studies providing information on mechanically ventilated patients without ARDS at the time of initiation of mechanical ventilation, and in which tidal volume was independently studied as a predictor variable for outcome, were included. The primary outcome was progression to ARDS.

RESULTS

The search yielded 1,704 studies, of which 13 were included in the final analysis. One randomized controlled trial was found; the remaining 12 studies were observational. The patient cohorts were significantly heterogeneous in composition and baseline risk for developing ARDS; therefore, a meta-analysis of the data was not performed. The majority of the studies (n = 8) showed a decrease in progression to ARDS with a lower tidal volume strategy. ARDS developed early in the course of illness (5 hours to 3.7 days). The development of ARDS was associated with increased mortality, lengths of stay, mechanical ventilation duration, and nonpulmonary organ failure.

CONCLUSIONS

In mechanically ventilated patients without ARDS at the time of endotracheal intubation, the majority of data favors lower tidal volume to reduce progression to ARDS. However, due to significant heterogeneity in the data, no definitive recommendations can be made. Further randomized controlled trials examining the role of lower tidal volumes in patients without ARDS, controlling for ARDS risk, are needed.

Clinical and demographic factors associated with antipyretic use in gram-negative severe sepsis and septic shock

BACKGROUND

Antipyretic therapy is commonly prescribed for patients with infection, but studies of its impact on clinical outcomes have yielded mixed results. No data exist to characterize the use of antipyretic medications in patients with severe sepsis or septic shock.

OBJECTIVE

To identify clinical and demographic factors associated with antipyretic medication administration in severe sepsis and septic shock.

METHODS

This single-center, retrospective, cohort study assessed febrile patients (temperature ≥ 38.3 °C) with gram-negative severe sepsis or septic shock at an 1111-bed academic medical center between January 2002 and February 2008. Patients were excluded if they had liver disease, acute brain injury, or allergy to acetaminophen. Generalized estimating equations were used to estimate the effect of clinical factors on treatment of patients with antipyretic medications.

RESULTS

Although 76% of patients in this febrile cohort (n = 241) were prescribed an antipyretic agent, only 42% received antipyretic therapy; 95% of the doses were acetaminophen. Variables associated with antipyretic treatment were maximum body temperature (OR 2.11, 95% CI 1.53 to 2.89), time after sepsis diagnosis (OR 0.88, 95% CI 0.82 to 0.95), surgery during hospitalization (OR 0.49, 95% CI 0.31 to 0.80), death within 36 hours (OR 0.35, 95% CI 0.15 to 0.85), and mechanical ventilation (OR 0.58, 95% CI 0.34 to 0.98). Severity of illness factors, demographic factors, and patient treatment location did not predict who would receive antipyretic therapy.

CONCLUSIONS

Most febrile episodes in patients with gram-negative severe sepsis or septic shock were not treated with antipyretic medications. Further studies are needed to demonstrate the effect of antipyretics on clinically relevant outcomes in severe sepsis and septic shock.

Generational influences in academic emergency medicine: teaching and learning, mentoring, and technology (part I)

For the first time in history, four generations are working together-traditionalists, baby boomers, generation Xers (Gen Xers), and millennials. Members of each generation carry with them a unique perspective of the world and interact differently with those around them. Through a review of the literature and consensus by modified Delphi methodology of the Society for Academic Emergency Medicine Aging and Generational Issues Task Force, the authors have developed this two-part series to address generational issues present in academic emergency medicine (EM). Understanding generational characteristics and mitigating strategies can help address some common issues encountered in academic EM. Through recognition of the unique characteristics of each of the generations with respect to teaching and learning, mentoring, and technology, academicians have the opportunity to strategically optimize interactions with one another.