Ventilator-associated pneumonia rates at major trauma centers compared with a national benchmark: a multi-institutional study of the AAST

Variation in Risk-Adjusted Ventilator-Associated Pneumonia (VAP) Days Within a Quality Collaborative

INTRODUCTION

Ventilator-associated pneumonia (VAP) is associated with increased mortality, prolonged mechanical ventilation, and longer intensive care unit stays. The rate of VAP (VAPs per 1000 ventilator days) within a hospital is an important quality metric. Despite adoption of preventative strategies, rates of VAP in injured patients remain high in trauma centers. Here, we report variation in risk-adjusted VAP rates within a statewide quality collaborative.

METHODS

Using Michigan Trauma Quality Improvement Program data from 35 American College of Surgeons-verified Level I and Level II trauma centers between November 1, 2020 and January 31, 2023, a patient-level Poisson model was created to evaluate the risk-adjusted rate of VAP across institutions given the number of ventilator days, adjusting for injury severity, physiologic parameters, and comorbid conditions. Patient-level model results were summed to create center-level estimates. We performed observed-to-expected adjustments to calculate each center's risk-adjusted VAP days and flagged outliers as hospitals whose confidence intervals lay above or below the overall mean.

RESULTS

We identified 538 VAP occurrences among a total of 33,038 ventilator days within the collaborative, with an overall mean of 16.3 VAPs per 1000 ventilator days. We found wide variation in risk-adjusted rates of VAP, ranging from 0 (0-8.9) to 33.0 (14.4-65.1) VAPs per 1000 d. Several hospitals were identified as high or low outliers.

CONCLUSIONS

There exists significant variation in the rate of VAP among trauma centers. Investigation of practices and factors influencing the differences between low and high outlier institutions may yield information to reduce variation and improve outcomes.

Fever and infections in surgical intensive care: an American Association for the Surgery of Trauma Critical Care Committee clinical consensus document

The evaluation and workup of fever and the use of antibiotics to treat infections is part of daily practice in the surgical intensive care unit (ICU). Fever can be infectious or non-infectious; it is important to distinguish between the two entities wherever possible. The evidence is growing for shortening the duration of antibiotic treatment of common infections. The purpose of this clinical consensus document, created by the American Association for the Surgery of Trauma Critical Care Committee, is to synthesize the available evidence, and to provide practical recommendations. We discuss the evaluation of fever, the indications to obtain cultures including urine, blood, and respiratory specimens for diagnosis of infections, the use of procalcitonin, and the decision to initiate empiric antibiotics. We then describe the treatment of common infections, specifically ventilator-associated pneumonia, catheter-associated urinary infection, catheter-related bloodstream infection, bacteremia, surgical site infection, intra-abdominal infection, ventriculitis, and necrotizing soft tissue infection.

Association between ventilator-associated events and implementation of acute respiratory distress syndrome (ARDS) ventilator weaning protocol

BACKGROUND

Acute respiratory distress syndrome (ARDS) is a severe and life-threatening condition that can occur in critically ill patients. Mechanical ventilation is a commonly used intervention with ARDS patients, but weaning patients off the ventilator can be challenging. An ARDSnet-like ventilator weaning protocol was implemented with the goal of reducing triggers for ventilator-associated events (VAEs).

METHODS

The implementation of the new protocol was used to complete a retrospective investigation of patient outcomes for 1,233 ventilator periods. Periods were included between April and December 2022 for any ventilated patient lasting at least 4 days. National Health Care Safety Network VAE criteria were used to surveille the patient data. Triggers were based on the positive end-expiratory pressure increases or fraction of inspired oxygen (FiO₂) increases. The preset weaning criteria was a reduction by 2 cmH2O per 24 hours.

RESULTS

Of the total 1,233 individual ventilator periods, VAE criteria were met in 10%. Of the total 126 periods with VAE, 39.2% met the criteria for appropriate protocol implementation. There was a statistically significant relationship between VAE identification and implementation of the protocol.

CONCLUSIONS

The implementation of a protocol for ventilator weaning affects the outcome of developing a VAE. The findings emphasize the importance of implementing the ARDS weaning protocol as a template to reduce the triggers for VAEs and improve overall patient outcomes.

Ventilator-associated Events Surveillance in a Trauma Intensive Care Unit: A Prospective Study of Incidence, Predictive Values, Sensitivity, Specificity, Accuracy, and Concordance with Ventilator-associated Pneumonia

Introduction

The Centres for Disease Control and Prevention (CDC) introduced a new definition of ventilator-associated events (VAEs) in 2013 in place of longstanding ventilator-associated pneumonia (VAP) definition. Three entities under VAE, ventilator-associated condition (VAC), infection-related ventilator-associated complication (IVAC), and possible ventilator-associated pneumonia (PVAP), were introduced.

Objectives

To assess the incidence of all VAEs in a tertiary care trauma ICU and to find the predictive value of VAE and sensitivity of VAE definitions for VAP.

Design

Cohort prospective study at trauma intensive care unit (ICU) of PGIMER, Chandigarh, from July 2018 till June 2019.

Materials and methods

Patients admitted in trauma ICU were checked for VAP and VAE criteria defined by CDC.

Results

Four hundred and sixty five patients were observed. Around 378 patients were included in the study with 4046 patient days and 3031 mechanical ventilation (MV) days. Incidence rate of PVAP, IVAC, VAC, and VAP was 2.97, 6.60, 10.23, and 9.24 per 1000 ventilator days, respectively. Sensitivity, specificity, positive predictive value, and negative predictive value (NPV) of diagnosing VAP were 0.61, 0.97, 0.68, and 0.97 for VAC; 0.80, 0.97, 0.57, and 0.99 for IVAC; and 0.78, 0.94, 0.25, and 0.9 for PVAP, respectively. Kendall's W test showed that there was very poor concordance between VAP and VAE.

How to cite this article

Kaur K, Jain K, Biswal M, Dayal SK. Ventilator-associated Events Surveillance in a Trauma Intensive Care Unit: A Prospective Study of Incidence, Predictive Values, Sensitivity, Specificity, Accuracy, and Concordance with Ventilator-associated Pneumonia. Indian J Crit Care Med 2022;26(5):584–590.

Making Ventilator Associated Pneumonia Rate a Meaningful Quality Marker

INTRODUCTION

Ventilator associated pneumonia (VAP) rate has been tracked as a comparable quality measure but there is significant variation between types of ICUs. We sought to understand variability and improve its utility as a marker of quality.

METHODS

The National Trauma Database was surveyed to identify risk factors for VAP. Logistic regression, χ², Student's T-test or Mann-Whitney U test were used.

RESULTS

Risk factors associated with developing VAP were: injury severity score (ISS) (OR 1.03, 95% CI 1.03 -1.04), prehospital assisted respiration (PHAR) (OR 1.10, 1.03 -1.17), thoracic injuries (OR 2.28, 1.69-3.08), diabetes (OR 1.32, 1.20 -1.46), male gender (OR 1.38, 1.28 -1.60), care at a teaching hospital (OR 1.40, 1.29 -1.47) and unplanned intubation (OR 2.76, 2.52-3.03).

DISCUSSION

ISS, PHAR, diabetes, male gender, care at a teaching hospital and unplanned intubation are risk factors for the development of VAP. These factors should be accounted for in order to make VAP an effective quality marker.

Deep odontogenic infections-identifying risk factors for nosocomial pneumonia

OBJECTIVES

To evaluate occurrence and risk factors for pneumonia in patients with deep odontogenic infection (OI).

MATERIALS AND METHODS

All patients treated for deep OIs and requiring intensive care and mechanical ventilation were included. The outcome variable was diagnosis of nosocomial pneumonia. Primary predictor variables were re-intubation and duration of mechanical ventilation. The secondary predictor variable was length of hospital stay (LOHS). The explanatory variables were gender, age, current smoking, current heavy alcohol and/or drug use, diabetes, and chronic pulmonary disease.

RESULTS

Ninety-two patients were included in the analyses. Pneumonia was detected in 14 patients (15%). It was diagnosed on postoperative day 2 to 6 (median 3 days, mean 3 days) after primary infection care. Duration of mechanical ventilation (p = 0.028) and LOHS (p = 0.002) correlated significantly with occurrence of pneumonia. In addition, re-intubation (p = 0.004) was found to be significantly associated with pneumonia; however, pneumonia was detected in 75% of these patients prior to re-intubation. Two patients (2%) died during intensive care unit stay, and both had diagnosed nosocomial pneumonia. Smoking correlated significantly with pneumonia (p = 0.011).

CONCLUSION

Secondary pneumonia due to deep OI is associated with prolonged hospital care and can predict the risk of death. Duration of mechanical ventilation should be reduced with prompt and adequate OI treatment, whenever possible. Smokers with deep OI have a significantly higher risk than non-smokers of developing pneumonia.

CLINICAL RELEVANCE

Nosocomial pneumonia is a considerable problem in OI patients with lengthy mechanical ventilation. Prompt and comprehensive OI care is required to reduce these risk factors.

Severe trauma patients and nursing practice-associated infections

AIMS

Our study examined factors influencing the development of healthcare-associated infections in the intensive care unit (ICU) of a tertiary hospital in southern Spain.

BACKGROUND

Healthcare-associated infections are a frequent adverse event, significantly lengthening patient stays in the ICU. Nursing practice is a key factor in the infection control process.

DESIGN

A retrospective longitudinal study with two observation periods (admission and discharge) was performed in an ICU of a tertiary hospital.

METHODS

We analysed patient records for those admitted to this unit coded as CIE 800-959.9 from 2012 to 2016. Using binomial logistic regression analysis, we analysed factors associated with healthcare-associated infections.

RESULTS

We analysed 375 records (men: 78.1%; average age: 46.63 years). Of these, 9.2% patients acquired a healthcare-associated infection during their stay. Nursing practice-related factors significantly associated with the development of infection were the number of days connected to mechanical ventilation and the number of days in the ICU.

CONCLUSION

Healthcare-associated infections in patients with severe trauma admitted to the ICU are mainly associated with the management of invasive techniques. A multidisciplinary approach should focus on the review of action and care plans.

Is it time to measure complications from the National Trauma Data Bank? A longitudinal analysis of recent reporting trends

BACKGROUND

Payers have approached select complications as never events, yet there is rationale that achieving a zero incidence of these events is impractical. Prior 2005 National Trauma Data Bank (NTDB) analysis showed high rates (37%) of centers reporting no complications data making national estimates for determining standardized complication rates difficult to ascertain.

METHODS

The 2008-2012 NTDB National Sample Program nationally weighted files were used to calculate yearly national estimates. Rates were compared in all centers and those reporting complications data. Hospital characteristics were compared using Student t test. In 2011, an other complication category was introduced; overall rates were calculated with and without this category. Yearly estimates were reported for patients receiving care within centers reporting complications data.

RESULTS

From 2008-2012 NTDB, there were raw data on 3,657,884 patients. A total of 594,894 patients (16.3%) experienced one or more complications (82.7% one complication; 17.3% two or more complications). Excluding the other complication category, the overall weighted rate was 8.4% to 9.2%. Pneumonia was the most common complication (2.7-3.0%), occurring at twice the 2005 rate. The number of centers reporting no complications data dropped to 8.1% in 2011 (2008, 14.5%; 2009, 18.2%; 2010, 15.9%; 2012, 8.9%). By 2012, nearly all level I centers reported complications, whereas 46.4% of level IVs reported none (I 0.5%, II 2.7%, III 8.5%, p = 0.04). Data were reported the least frequently in nonteaching hospitals (15.8%, p = 0.007), those in the South (19.6%, p = 0.007), and those with less than 200 beds (23.6%, p = 0.005).

CONCLUSION

Overall rates of complications from 2008 to 2012 were nearly twofold higher than 2005 data. Reporting has increased, and NTDB may provide a valuable platform for establishing rational and achievable measures for specific complications.

LEVEL OF EVIDENCE

Prognostic and epidemiological, level IV.

Ventilator-associated events, not ventilator-associated pneumonia, is associated with higher mortality in trauma patients

BACKGROUND

Ventilator-associated events (VAE), using objective diagnostic criteria, are the preferred quality indicator for patients requiring mechanical ventilation (MV) for greater than 48 hours. We aim to identify the occurrence of VAE in our trauma population, the impact on survival, and length of stay, as compared to the traditional definition of ventilator-associated pneumonia (VAP).

METHODS

This retrospective review included adult trauma patients, who were Washington residents, admitted between 2012 and 2017, and required at least 3 days of MV. Exclusions included patients with Abbreviated Injury Scale head score greater than 4 and burn related mechanisms of injury. We matched trauma registry data with our institutional, physician-adjudicated, and culture-confirmed ventilator event database. We compared the clinical outcomes of ventilator-free days, intensive care unit length of stay, hospital length of stay, and likelihood of death between VAE and VAP.

RESULTS

One thousand five hundred thirty-three trauma patients met criteria; 124 (8.1%) patients developed VAE, 114 (7.4%) patients developed VAP, and 63 (4.1%) patients met criteria for both VAE and VAP. After adjusted analyses, patients with VAE were more likely to die (hazard ratio [HR], 2.86; 95% confidence interval [CI], 1.44-5.68), than those with VAP, as well those patients with neither diagnosis (HR, 2.83; 95% CI, 1.83-4.38). Patients with VAP were no more likely to die (HR, 1.55; 95% CI, 0.91-2.68) than those with neither diagnosis. Patients with VAE had fewer ventilator-free days than those with VAP (HR, -2.71; 95% CI, -4.74 to -0.68).

CONCLUSION

Critically injured trauma patients who develop VAE are three times more likely to die and utilize almost 3 days more MV than those that develop VAP. The objective criteria of VAE make it a promising indicator on which quality indicator efforts should be focused. Future studies should be aimed at identification of modifiable risk factors for VAE and their impact on outcome, as these patients are at high risk for death.

LEVEL OF EVIDENCE

Retrospective cohort study, level III.

Pneumonia in severely injured patients with thoracic trauma: results of a retrospective observational multi-centre study

Background

While the incidence and aspects of pneumonia in ICU patients has been extensively discussed in the literature, studies on the occurrence of pneumonia in severely injured patients are rare. The aim of the present study is to elucidate factors associated with the occurrence of pneumonia in severely injured patients with thoracic trauma.

Setting

Level-I University Trauma Centres associated with the TraumaRegister DGU®.

Methods

A total of 1162 severely injured adult patients with thoracic trauma documented in the TraumaRegister DGU® (TR-DGU) were included in this study. Demographic data, injury severity, duration of mechanical ventilation (MV), duration of ICU stay, occurrence of pneumonia, bronchoalveolar lavage, aspiration, pathogen details, and incidences of mortality were evaluated. Statistical evaluation was performed using SPSS (Version 25.0, SPSS, Inc.) software.

Results

The overall incidence of pneumonia was 27.5%. Compared to patients without pneumonia, patients with pneumonia had sustained more severe injuries (mean ISS: 32.6 vs. 25.4), were older (mean age: 51.3 vs. 47.5) and spent longer periods under MV (mean: 368.9 h vs. 114.9 h). Age, sex (male), aspiration, and duration of MV were all independent predictors for pneumonia occurrence in a multivariate analysis. The cut-off point for duration of MV that best discriminated between patients who would and would not develop pneumonia during their hospital stay was 102 h. The extent of thoracic trauma (AIS_thorax), ISS, and presence of pulmonary comorbidities did not show significant associations to pneumonia incidence in our multivariate analysis. No significant difference in mortality between patients with and without pneumonia was observed.

Conclusions

Likelihood of pneumonia increases with age, aspiration, and duration of MV. These parameters were not found to be associated with differences in outcomes between patients with and without pneumonia. Future studies should focus on independent parameters to more clearly identify severely injured subgroups with a high risk of developing pneumonia.

Level of evidence

Level II - Retrospective medical record review.

Trauma ICU Prevalence Project: the diversity of surgical critical care

Background

Surgical critical care is crucial to the care of trauma and surgical patients. This study was designed to provide a contemporary assessment of patient types, injuries, and conditions in intensive care units (ICU) caring for trauma patients.

Methods

This was a multicenter prevalence study of the American Association for the Surgery of Trauma; data were collected on all patients present in participating centers’ trauma ICU (TICU) on November 2, 2017 and April 10, 2018.

Results

Forty-nine centers submitted data on 1416 patients. Median age was 58 years (IQR 41–70). Patient types included trauma (n=665, 46.9%), non-trauma surgical (n=536, 37.8%), medical (n=204, 14.4% overall), or unspecified (n=11). Surgical intensivists managed 73.1% of patients. Of ICU-specific diagnoses, 57% were pulmonary related. Multiple high-intensity diagnoses were represented (septic shock, 10.2%; multiple organ failure, 5.58%; adult respiratory distress syndrome, 4.38%). Hemorrhagic shock was seen in 11.6% of trauma patients and 6.55% of all patients. The most common traumatic injuries were rib fractures (41.6%), brain (38.8%), hemothorax/pneumothorax (30.8%), and facial fractures (23.7%). Forty-four percent were on mechanical ventilation, and 17.6% had a tracheostomy. One-third (33%) had an infection, and over half (54.3%) were on antibiotics. Operations were performed in 70.2%, with 23.7% having abdominal surgery. At 30 days, 5.4% were still in the ICU. Median ICU length of stay was 9 days (IQR 4–20). 30-day mortality was 11.2%.

Conclusions

Patient acuity in TICUs in the USA is very high, as is the breadth of pathology and the interventions provided. Non-trauma patients constitute a significant proportion of TICU care. Further assessment of the global predictors of outcome is needed to inform the education, research, clinical practice, and staffing of surgical critical care providers.

Level of evidence

IV, prospective observational study.

Variations of the lung microbiome and immune response in mechanically ventilated surgical patients

Mechanically ventilated surgical patients have a variety of bacterial flora that are often undetectable by traditional culture methods. The source of infection in many of these patients remains unclear. To address this clinical problem, the microbiome profile and host inflammatory response in bronchoalveolar lavage samples from the surgical intensive care unit were examined relative to clinical pathology diagnoses. The hypothesis was tested that clinical diagnosis of respiratory tract flora were similar to culture positive lavage samples in both microbiome and inflammatory profile. Bronchoalveolar lavage samples were collected in the surgical intensive care unit as standard of care for intubated individuals with a clinical pulmonary infection score of >6 or who were expected to be intubated for >48 hours. Cytokine analysis was conducted with the Bioplex Pro Human Th17 cytokine panel. The microbiome of the samples was sequenced for the 16S rRNA region using the Ion Torrent. Microbiome diversity analysis showed the culture-positive samples had the lowest levels of diversity and culture negative with the highest based upon the Shannon-Wiener index (culture positive: 0.77 ± 0.36, respiratory tract flora: 2.06 ± 0.73, culture negative: 3.97 ± 0.65). Culture-negative samples were not dominated by a single bacterial genera. Lavages classified as respiratory tract flora were more similar to the culture-positive in the microbiome profile. A comparison of cytokine expression between groups showed increased levels of cytokines (IFN-g, IL-17F, IL-1B, IL-31, TNF-a) in culture-positive and respiratory tract flora groups. Culture-positive samples exhibited a more robust immune response and reduced diversity of bacterial genera. Lower cytokine levels in culture-negative samples, despite a greater number of bacterial species, suggest a resident nonpathogenic bacterial community may be indicative of a normal pulmonary environment. Respiratory tract flora samples were most similar to the culture-positive samples and may warrant classification as culture-positive when considering clinical treatment.

Danger signals from mitochondrial DAMPS in trauma and post-injury sepsis

In all multicellular organisms, immediate host responses to both sterile and infective threat are initiated by very primitive systems now grouped together under the general term 'danger responses'. Danger signals are generated when primitive 'pattern recognition receptors' (PRR) encounter activating 'alarmins'. These molecular species may be of pathogenic infective origin (pathogen-associated molecular patterns) or of sterile endogenous origin (danger-associated molecular patterns). There are many sterile and infective alarmins and there is considerable overlap in their ability to activate PRR, but in all cases the end result is inflammation. It is the overlap between sterile and infective signals acting via a relatively limited number of PRR that generally underlies the great clinical similarity we see between sterile and infective systemic inflammatory responses. Mitochondria (MT) are evolutionarily derived from bacteria, and thus they sit at the crossroads between sterile and infective danger signal pathways. Many of the molecular species in mitochondria are alarmins, and so the release of MT from injured cells results in a wide variety of inflammatory events. This paper discusses the known participation of MT in inflammation and reviews what is known about how the major.

Extended infusion versus intermittent infusion of imipenem in the treatment of ventilator-associated pneumonia

Background

Mechanical ventilation support can be the main source of ventilator-associated pneumonia (VAP). VAP is a serious infection that may be associated with dangerous gram-negative bacteria mainly, and it leads to an increase in the mortality in the intensive care unit (ICU). Imipenem is one of the strongest antibiotics now available for treating VAP which is associated with gram-negative and gram-positive bacteria, and it belongs to beta-lactam antibiotic group (carbapenem).

Objective

This study tried to investigate the efficacy of imipenem against VAP when it was infused within 180 min versus the efficacy when it was infused within 30–60 min.

Setting

This study was conducted in main ICU in general hospital which consists of surgical and medical beds within 2 years. One hundred and eighty-seven patients were enrolled on it.

Method

This study is a retrospective cohort which was conducted within 2 years. The efficacy of imipenem which was administered by intermittent infusion (30–60 min) within first year was compared with the efficacy of imipenem which was administered by extended infusion (180 min) within second year in the field of VAP curing and cost reduction. All data were collected retrospectively from patient medical files and were statistically analyzed by SPSS version 20.

Main outcome

The study was designed to measure clinical and cost reduction outcomes, mortality and hospital stay.

Results

The results indicated that there is a significant decrease in mortality, number of recurrent infection, and ICU stay length, and the number of mechanical ventilator days was associated with extended imipenem infusion during the second year of the study.

Conclusion

The use of imipenem with extended infusion over 3 hours enhances its clinical outcomes in the treatment of VAP.

Intratracheal instillation of neutrophils rescues bacterial overgrowth initiated by trauma damage-associated molecular patterns

BACKGROUND

Nosocomial pneumonias are common in trauma patients and so interventions to prevent and treat nosocomial pneumonia may improve outcomes. Our prior work strongly suggests that tissue injury predisposes to infections like nosocomial pneumonia because mitochondrial debris originating from injured cells contains damage-associated molecular patterns that can reduce neutrophil (PMN) migration into the airway and diminish PMN function in response to bacterial inoculation of the airway. This suggested that putting exogenous "normal" PMN into the airway might be beneficial.

METHODS

Postinjury pneumonia (PNA) commonly arises in two groups, early, community-acquired PNA (CAP) and later hospital-acquired PNA (HAP). Posttraumatic early-onset CAP and late-onset HAP were modeled in CD-1 mice using Staphylococcus aureus or Pseudomonas aeruginosa instilled intratracheal (i.t.) at clinically relevant times with or without extrapulmonary injuries mimicked by an intraperitoneal application of mitochondrial damage-associated molecular patterns. We applied bone marrow-derived PMN (BM-PMN) intratracheally to assess their effect on bacterial clearance in the lung.

RESULTS

BM-PMN instillation i.t. had no untoward clinical effects on recipient animals. In both the early/CAP and late/HAP models, clearance of the bacterial inoculum from the lung was suppressed by mitochondrial debris and restored to uninjured levels by i.t. instillation of exogenous BM-PMN. Furthermore, PMN instillation cleared the inoculum of P. aeruginosa that could not be cleared by uninjured mice. Instillation of PMN into the lung, even across strains (CD-1 vs. C57BL/6) had no injurious effect.

CONCLUSION

These initial studies suggest PMN instillation (i.t.) is worthy of further study as a potential adjunctive therapy aimed at decreasing the morbidity of lung infections in trauma patients. Moreover, PMN instillation (i.t.) may represent a unique means of preventing or treating pneumonia after serious injury that is completely independent of the need for antibiotic use.

Designing Technology to Decrease Pneumonia in Intubated Trauma Patients

Trauma patients are at increased risk for developing ventilator-associated pneumonia. Sixty adult trauma intensive care unit patients were audited 3 months prepractice change, and 30 were audited postpractice change. Quality improvement interventions included staff education of a redesigned electronic medical record ventilator bundle and chlorhexidine gluconate administration timing practice change. Postpractice change audits revealed 2-hour chlorhexidine gluconate documentation increased from 38.3% to 73.3% and incidence of pneumonia in intubated patients decreased by 62%. Early initiation of chlorhexidine gluconate mouth care utilizing electronic medical record technology may help reduce pneumonia in intubated patients, hospital length of stay, overall health costs, and improve documentation.

Methicillin-Resistant Staphylococcus aureus Pneumonia in Critically Ill Trauma and Burn Patients: A Retrospective Cohort Study

BACKGROUND

The timing and risk factors for methicillin-resistant Staphylococcus aureus (MRSA) pneumonia in trauma patients are not well characterized. This information is critical for the selection of appropriate empiric antibiotics. The objective of this study was to determine the incidence of MRSA pneumonia in early-onset and late-onset pneumonia and to identify risk factors for MRSA in the trauma-burn intensive care unit (ICU).

PATIENTS AND METHODS

We conducted a retrospective cohort study from January 2012 to March 2015 of patients in the trauma and burn ICU with clinical and microbiologic evidence of pneumonia. Demographics, injury type and severity, co-morbidities, antimicrobial agents, and MRSA nasal colonization at ICU admission were extracted from the medical record. A multi-variable exact logistic regression was performed to assess predictors of MRSA pneumonia.

RESULTS

Eighty patients with 88 episodes of pneumonia were included in the cohort. Ten patients had MRSA pneumonia, an overall incidence of 11.4% of pneumonia episodes with a median onset of seven days. The proportion of MRSA pneumonia episodes was not significantly different in early-onset (<5 days) or late-onset pneumonia, and there were no statistically significant risk factors for developing MRSA pneumonia. The majority of patients with MRSA had at least one known risk factor including homelessness, substance abuse, and receipt of broad-spectrum antibiotic agents.

CONCLUSIONS

The 11.4% overall incidence of MRSA pneumonia in this trauma-burn cohort was similar to what has been reported in other trauma populations, although MRSA was equally likely to be identified in early- and late-onset pneumonia. Our results suggest that risk factors other than duration of hospitalization may be important considerations in the decision to initiate MRSA-active empiric therapy for pneumonia in the trauma-burn ICU.

Risk factors for ventilator-associated pneumonia: among trauma patients with and without brain injury

Ventilator-associated pneumonia (VAP) rates remain highest among trauma and brain injured patients; yet, no research compares VAP risk factors between the 2 groups. This retrospective, case-controlled study identified risk factors for VAP among critically ill trauma patients with and without brain injury. Data were abstracted on trauma patients with (cases) and without (controls) brain injury. Data gathered on n = 157 subjects. Trauma patients with brain injury had more emergent and field intubations. Age was strongest predictor of VAP in cases, and ventilator days predicted VAP in controls. Trauma patients with brain injury may be at higher risk for VAP.

THE GLYCOCALYX AND TRAUMA: A REVIEW

In the United States trauma is the leading cause of mortality among those under the age of 45, claiming approximately 192,000 lives each year. Significant personal disability, lost productivity, and long-term healthcare needs are common and contribute 580 billion dollars in economic impact each year. Improving resuscitation strategies and the early acute care of trauma patients has the potential to reduce the pathological sequelae of combined exuberant inflammation and immune suppression that can co-exist, or occur temporally, and adversely affect outcomes. The endothelial and epithelial glycocalyx has emerged as an important participant in both inflammation and immunomodulation. Constituents of the glycocalyx have been used as biomarkers of injury severity and have the potential to be target(s) for therapeutic interventions aimed at immune modulation. In this review, we provide a contemporary understanding of the physiologic structure and function of the glycocalyx and its role in traumatic injury with a particular emphasis on lung injury.

Pharmacologic Stress Gastropathy Prophylaxis May Not Be Necessary in At-Risk Surgical Trauma ICU Patients Tolerating Enteral Nutrition

OBJECTIVE

Stress gastropathy is a rare complication of the intensive care unit stay with high morbidity and mortality. There are data that support the concept that patients tolerating enteral nutrition have sufficient gut blood flow to obviate the need for prophylaxis; however, no robust studies exist. This study assesses the incidence of clinically significant gastrointestinal bleeding in surgical trauma intensive care unit (STICU) patients at risk of stress gastropathy secondary to mechanical ventilation receiving enteral nutrition without pharmacologic prophylaxis.

DESIGN

A retrospective cohort study of records from 2008 to 2013.

SETTING

Adult patients in a single-center STICU were included.

PATIENTS

Patients were included if they received full enteral nutrition while on mechanical ventilation. Exclusion criteria were coagulopathy, glucocorticoid use, prior-to-admission acid-suppressive therapy use, direct trauma or surgery to the stomach, failure to tolerate goal enteral nutrition, orders to allow natural death, and deviation from the intervention.

INTERVENTION

Pharmacologic stress ulcer prophylaxis was discontinued once enteral nutrition was providing full caloric requirements for patients requiring mechanical ventilation.

MEASUREMENTS AND MAIN RESULTS

A total of 200 patients were included. The median age was 42 years, 83.0% were male, and 96.0% were trauma patients. The incidence of clinically significant gastrointestinal bleeding was 0.50%, with a subset analysis of traumatic brain injury patients yielding an incidence of 0.68%. Rates of ventilator-associated pneumonia and Clostridium difficile infection were low at 1.0 case/1000 ventilator days and 0.2 events/1000 patient days, respectively. Hospital all-cause mortality was 2.0%. Cost savings of US$121/patient stay were realized.

CONCLUSION

Stress gastropathy is rare in this population. Surgical and trauma patients at risk for stress gastropathy did not benefit from continued pharmacologic prophylaxis once they tolerated enteral nutrition. Pharmacologic prophylaxis may safely be discontinued in this patient population. Further investigation is warranted to determine whether continued prophylaxis after attaining enteral feeding goals is detrimental.

The Role of Elevated Lactate as a Risk Factor for Pulmonary Morbidity After Early Fixation of Femoral Shaft Fractures

OBJECTIVES

To evaluate lactate levels before reamed intramedullary nailing (IMN) of femur fractures treated with early fixation.

DESIGN

Retrospective study.

SETTING

Three academic, tertiary care trauma centers.

PATIENTS

Age ≥18 years, injury severity score ≥17, admission lactate ≥ 2.5 mmol/L, elevated preoperative lactate = preoperative lactate ≥ 2.5 mmol/L.

INTERVENTION

Reamed IMN of femur fracture within 24 hours.

MAIN OUTCOME MEASURE

Total duration of mechanical ventilation, pulmonary complications (PC) = duration of mechanical ventilation ≥5 days.

RESULTS

Four hundred and fourteen patients identified; 294/414 (71.0%) with admission lactate ≥ 2.5 mmol/L. No difference in PC among the groups (86/294, 29.3% vs. 28/120, 23.3%; P = 0.22). Median admission lactate: 3.7 (interquartile range: 3.0-4.6); median preoperative lactate: 2.8 (interquartile range: 1.9-3.5). 184/294 (62.6%) demonstrated an elevated preoperative lactate (≥ 2.5 mmol/L) before fracture fixation. No difference in elevated preoperative lactate and vent days (4.8 ± 9.9 vs. 3.9 ± 6.0, P = 0.41) or PC (50/86, 58.1% vs. 134/208, 64.4%; P = 0.31). There was no difference in PC when preoperative lactate was considered separately for a lactate ≥3.0 (34/123, 27.6% vs. 52/171, 30.4%; P = 0.61), ≥3.5 (21/79, 26.6% vs. 65/215, 30.2%; P = 0.54), or ≥4.0 (14/50, 28.0% vs. 72/244, 29.5%; P = 0.83). Multivariable linear regression modeling demonstrated that admission lactate [coefficient of variation: 0.84, standard error: 0.33, 95% confidence interval (CI): 0.20-1.49] was correlated with duration of mechanical ventilation, after adjusting for emergency department Glasgow Coma Scale, age, chest Abbreviated Injury Scale (AIS) score, abdominal AIS, and admission glucose. Logistic regression demonstrated admission lactate was also significantly associated with PC (odds ratio: 1.26, 95% CI: 1.03-1.53) after controlling for age, admission Glasgow Coma Scale, chest AIS, abdominal AIS, admission pulse and admission glucose; preoperative lactate was not a risk factor (odds ratio: 0.84, 95% CI: 0.65-1.09) for PC.

CONCLUSION

Median admission lactate of 3.7 mmol/L was associated with duration of mechanical ventilation ≥5 days, whereas median preoperative lactate of 2.8 mmol/L was not, when multisystem trauma patients with a femoral shaft fracture were treated with reamed IMN within 24 hours after admission.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Ventilator-Associated Pneumonia in Trauma Patients: Different Criteria, Different Rates

BACKGROUND

No consensus exists regarding the definition of ventilator-associated pneumonia (VAP). Even within a single institution, inconsistent diagnostic criteria result in conflicting rates of VAP. As a Level 1 trauma center participating in the Trauma Quality Improvement Project (TQIP) and the National Healthcare Safety Network (NHSN), our institution showed inconsistencies in VAP rates depending on which criteria was applied. The purpose of this study was to compare VAP definitions, defined by culture-based criteria, National Trauma Data Bank (NTDB) and NHSN, using incidence in trauma patients.

METHODS

A retrospective chart review of consecutive trauma patients who were diagnosed with VAP and met pre-determined inclusion and exclusion criteria admitted to our rural, 861-bed, Level 1 trauma and tertiary care center between January 2008 and December 2011 was performed. These patients were identified from the National Trauma Registry of the American College of Surgeons (NTRACS) database and an in-house infection control database. Ventilator-associated pneumonia diagnosis criteria defined by the U.S. Center for Disease Control and Prevention (used by the NHSN), the NTDB, and our institutional, culture-based criteria gold standard were compared among patients.

RESULTS

Two hundred seventy-nine patients were diagnosed with VAP (25.4% met NHSN criteria, 88.2% met NTDB, and 76.3% met culture-based criteria). Only 58 (20.1%) patients met all three criteria. When NHSN criteria were compared with culture-based criteria, NHSN showed a high specificity (92.5%) and low sensitivity (28.2%). The positive predictive value (PPV) was 84.5%, but the negative predictive value (NPV) was 47.1%. The agreement between the NHSN and the culture-based criteria was poor (κ = 0.18). Conversely, the NTDB showed a lower specificity (57.8%), but greater sensitivity (86.4%) compared with culture-based criteria. The PPV and NPV were both 74% and the two criteria showed fair agreement (κ = 0.41).

CONCLUSIONS

The lack of standard diagnostic criteria for VAP resulted in variable reporting to different agencies. Emphasis on establishing a consensus VAP definition should be undertaken.

Beneficial Effects of CpG-Oligodeoxynucleotide Treatment on Trauma and Secondary Lung Infection

Although Streptococcus pneumoniae is usually found as a commensal in healthy individuals, it can act as a pathogen in trauma patients, causing such complications as early-onset pneumonia and sepsis. We discovered that treating mice with an A-class CpG-oligodeoxynucleotide (ODN) at 2 h after traumatic injury significantly improved mouse survival following early-onset secondary lung infection with S. pneumoniae. This study used mass cytometry (cytometry by time-of-flight) and Luminex technologies to characterize the cellular immune response to secondary S. pneumoniae lung infection at 1 and 3 d postinfection. We found increased expression of CD14, CD64, and PD-L1 on F4-80(+) and F4-80(+)CD11c(+) macrophages, CD11c(+) dendritic cells, and CD14(+)CD172a(+) cells after burn-injury and infection, supporting previous reports of innate immune cell activation in sepsis. CpG-ODN treatment at 2 h after burn-injury reversed these effects; improved pathogen clearance; and led to an increased expression of CD25, CD27, MHCII, and IL-17 on or in TCRγδ cells at 1 d postinfection. At 3 d postinfection, CpG-ODN treatment increased the expression of PD-L1 on innate cell subsets. Furthermore, we analyzed cytokine levels in lung-washout samples of TCRγδ cell-depleted (TCRγδ(-)) mice to demonstrate that the effects of CpG-ODN on cytokine expression after burn-injury and S. pneumoniae infection rely on functional TCRγδ cells. In summary, we demonstrate that cytometry by time-of-flight provides an effective strategy to systematically identify specific cellular phenotypic responses to trauma and bacterial pneumonia and to discover changes in immune system phenotypes associated with beneficial immunotherapy.

Mitochondrial damage-associated molecular patterns from fractures suppress pulmonary immune responses via formyl peptide receptors 1 and 2

BACKGROUND

No known biologic mechanisms link tissue injury with pneumonia (PNA). Neutrophils (PMNs) are innate immune cells that clear bacteria from the lung by migration toward chemoattractants and killing bacteria in neutrophil extracellular traps (NETs). We predicted that tissue injury would suppress PMN antimicrobial function in the lung. We have also shown that mitochondria-derived damage-associated molecular pattern molecules from the bone can alter PMN phenotype and so hypothesized that formyl peptides (FPs) from fractures predispose to PNA by suppressing PMN activity in the lung.

METHODS

Animal studies involved the following. (1) Rats were divided into three groups (10 per condition) as follows: (a) saline injection in the thigh (b) Staphylococcus aureus (SA, 3 × 10) injected intratracheally, or (c) pseudofracture (PsFx; bone supernatant injected in the thigh) plus intratracheally injected SA. (2) Rats were divided into four groups as follows: (a) control, (b) pulmonary contusion (PC), (c) PsFx, and (d) PC + PsFx. Bronchoalveolar lavage was performed 16 hours later. Clinical studies involved the following. (3) Human bone supernatant was assayed for its FP-receptor (FPR) stimulation. (4) Trauma patients' PMN (n = 32; mean ± SE Injury Severity Score [ISS], 27 ± 10) were assayed for chemotaxis (CTX) or treated with Phorbol 12-myristate 13-acetate (PMA, Phorbol ester) and analyzed for NET formation.

RESULTS

In the animal studies, (1) SA was rapidly cleared by the uninjured mice and PsFx markedly suppressed lung bacterial clearance (p < 0.01). (2a) PC induces PMN traffic to the lung, but PsFx decreases PC-induced PMN traffic (p < 0.01). (2b) SA increased bronchoalveolar lavage PMN, and PsFx decreased that influx (p < 0.01). In the clinical studies, (3) bone supernatant activates PMN both via FPR-1 and FPR-2. (4) Trauma decreases PMN CTX to multiple chemokines. Circulating PMNs show NETs spontaneously after trauma, but maximal NET formation is markedly attenuated.

CONCLUSION

Fractures may decrease lung bacterial clearance because FP suppresses PMN CTX to other chemoattractants via FPR-1/2. Trauma activates NETosis but suppresses maximal NETosis. Fractures decrease lung bacterial clearance by multiple mechanisms. PNA after fractures may reflect damage-associated molecular pattern-mediated suppression of PMN antimicrobial function in the lung.

Adherence to an established diagnostic threshold for ventilator-associated pneumonia contributes to low false-negative rates in trauma patients

BACKGROUND

The diagnosis of ventilator-associated pneumonia (VAP) in our institution has followed an established diagnostic threshold (DT) of equal to or greater than 10 colony-forming units (CFU) per milliliter on bronchoalveolar lavage (BAL) based on our previous study (PS). Because mortality from VAP is related to treatment delay, some have advocated a lower DT. The purpose of the current study (CS) was to evaluate the impact of adherence to this DT for VAP on false-negative (FN) rates and mortality in trauma patients.

METHODS

Consecutive patients over 9 years with VAP (defined as ≥10 CFU/mL in the BAL effluent) subsequent to the PS were identified. Data regarding each BAL performed and the colony counts of each organism identified were recorded. An FN BAL result was defined as any patient who had less than 10 CFU/mL and developed VAP with the same organism up to 7 days after the previous culture. The CS was then compared with the PS.

RESULTS

Over 9 years, 1,679 patients underwent 3,202 BALs. Of these, 79% were male, 88% experienced blunt injury, mean age and Injury Severity Score (ISS) were 44 years and 31, respectively. Overall, there were 73 FN BAL results (2.3%) in the CS compared with 3% in the PS (p = 0.092). In those patients with 10 organisms, the FN rate was reduced (7.5% vs. 11%, p = 0.045), and mortality was unchanged (5.4% vs. 8.3%, p = 0.361) in the CS compared with the PS. The use of the threshold equal to or greater than 10 resulted in a cumulative reduction in antibiotic charges of $1.57 million.

CONCLUSION

Continued adherence to the diagnostic threshold of equal to or greater than 10 for quantitative BAL in trauma patients has maintained a low incidence of FN BALs and reduced patient charges without impacting mortality. The purported benefit of a lower threshold is not supported. In addition, the potential sequelae of increased resistant organisms, antibiotic-related complications, and costs associated with prolonged unnecessary antibiotic exposure are minimized.

LEVEL OF EVIDENCE

Prognostic study, level III.

Impact of diagnostic criteria on the incidence of ventilator-associated pneumonia

BACKGROUND

Ventilator-associated pneumonia (VAP) is a frequent complication of prolonged invasive ventilation. Because VAP is largely preventable, its incidence has been used as an index of quality of care in the ICU. However, the incidence of VAP varies according to which criteria are used to identify it. We compared the incidence of VAP obtained with different sets of criteria.

METHODS

We collected data from all adult patients admitted to our 35-bed ICU over a 7-month period who had no pulmonary infection on admission or within the first 48 h and who required mechanical ventilation for > 48 h. To diagnose VAP, we applied six published sets of criteria and 89 combinations of criteria for hypoxemia, inflammatory response, purulence of tracheal secretions, chest radiography findings, and microbiologic findings of varying levels of severity. The variables used in each diagnostic algorithm were assessed daily.

RESULTS

Of 1,824 patients admitted to the ICU during the study period, 91 were eligible for inclusion. The incidence of VAP ranged from 4% to 42% when using the six published sets of criteria and from 0% to 44% when using the 89 combinations. The delay before diagnosis of VAP increased from 4 to 8 days with increasingly stringent criteria, and mortality increased from 50% to 80%.

CONCLUSIONS

Applying different diagnostic criteria to the same patient population can result in wide variation in the incidence of VAP. The use of different criteria can also influence the time of diagnosis and the associated mortality rate.

Differences between novel and conventional surveillance paradigms of ventilator-associated pneumonia

OBJECTIVE

To investigate the concordance between novel and conventional surveillance paradigms for ventilator-associated pneumonia (VAP).

METHODS

This study was conducted at a regional teaching hospital in southern Taiwan with 5 acute intensive care units. To assess the validity of novel ventilator-associated event (VAE) surveillance, we retrospectively applied the VAE algorithm to analyze all VAP cases that were identified using conventional definitions between April 2010 and February 2014. Patient outcomes, including ventilator days, hospital stay lengths, and in-hospital mortality were recorded.

RESULTS

Among 165 episodes of conventional VAP, 55 (33.3%), 40 (24.2%), 20 (12.1%), and 2 (1.2%) episodes were classified as a ventilator-associated condition, an infection-related ventilator-associated complication, possible VAP, and probable VAP, respectively, according to the new VAE algorithm. Changes in positive end-expiratory pressure and inspired oxygen fraction levels during the development of VAP were significant higher among each VAE category than for conventional VAP (all P < .001). In-hospital mortality was significantly higher among patients with ventilator-associated condition than for patients with conventional VAP (P = .0185).

CONCLUSIONS

In our study population, novel VAE surveillance only detected one-third of conventional VAP cases. Thus, more studies are needed to further validate VAE surveillance compared with conventional VAP by using strong microbiologic criteria, particularly bronchoalveolar lavage with a protected specimen brush for diagnosing VAP.

Impact of pathogen-directed antimicrobial therapy for ventilator-associated pneumonia in trauma patients on charges and recurrence

BACKGROUND

Ventilator-associated pneumonia (VAP) represents one of the driving forces behind antibiotic use in the ICU. In a previous study, we established a defined algorithm for treatment of hospital-acquired VAP dictated by the causative pathogen. The purpose of the current study was to evaluate the impact of this algorithm for hospital-acquired VAP on recurrence and charges in trauma patients.

STUDY DESIGN

Patients with VAP secondary to MRSA, Acinetobacter baumannii, Pseudomonas aeruginosa, Stenotrophomonas maltophilia, or Enterobacteriaceae during 5 years subsequent to the previous study were evaluated. All VAP were diagnosed using quantitative cultures of the bronchoalveolar lavage effluent. Duration of antimicrobial therapy was dictated by the causative pathogen. If microbiologic resolution, defined as <10(3) colony-forming units/mL, was achieved, therapy was stopped by day 10. The remainder received 14 days of therapy. Recurrence was defined as >10(5) colony-forming units/mL on subsequent bronchoalveolar lavage performed within 2 weeks after completion of appropriate therapy.

RESULTS

Five hundred and twenty-nine VAP episodes were identified in 381 patients. Overall recurrence was unchanged compared with the previous study (1.5% vs 2%; p = 0.3). There was a decrease in the number of bronchoalveolar lavages performed per patient compared with the previous study (1.6 vs 2.3; p = 0.24) and a reduction of 4.8 antibiotic days per VAP episode compared with the previous study. Both changes resulted in a cumulative reduction of $3,535.04 per patient, for a savings of $1.35 million during the study period.

CONCLUSIONS

Hospital-acquired VAP can be managed effectively by a defined course of therapy dictated by the causative pathogen. Adherence to an established algorithm simplified the management of VAP and contributed to a cumulative reduction in patient charges without impacting recurrence.

Electronic implementation of a novel surveillance paradigm for ventilator-associated events. Feasibility and validation

RATIONALE

Accurate surveillance of ventilator-associated pneumonia (VAP) is hampered by subjective diagnostic criteria. A novel surveillance paradigm for ventilator-associated events (VAEs) was introduced.

OBJECTIVES

To determine the validity of surveillance using the new VAE algorithm.

METHODS

Prospective cohort study in two Dutch academic medical centers (2011-2012). VAE surveillance was electronically implemented and included assessment of (infection-related) ventilator-associated conditions (VAC, IVAC) and VAP. Concordance with ongoing prospective VAP surveillance was assessed, along with clinical diagnoses underlying VAEs and associated mortality of all conditions. Consequences of minor differences in electronic VAE implementation were evaluated.

MEASUREMENTS AND MAIN RESULTS

The study included 2,080 patients with 2,296 admissions. Incidences of VAC, IVAC, VAE-VAP, and VAP according to prospective surveillance were 10.0, 4.2, 3.2, and 8.0 per 1000 ventilation days, respectively. The VAE algorithm detected at most 32% of the patients with VAP identified by prospective surveillance. VAC signals were most often caused by volume overload and infections, but not necessarily VAP. Subdistribution hazards for mortality were 3.9 (95% confidence interval, 2.9-5.3) for VAC, 2.5 (1.5-4.1) for IVAC, 2.0 (1.1-3.6) for VAE-VAP, and 7.2 (5.1-10.3) for VAP identified by prospective surveillance. In sensitivity analyses, mortality estimates varied considerably after minor differences in electronic algorithm implementation.

CONCLUSIONS

Concordance between the novel VAE algorithm and VAP was poor. Incidence and associated mortality of VAE were susceptible to small differences in electronic implementation. More studies are needed to characterize the clinical entities underlying VAE and to ensure comparability of rates from different institutions.

Influence of bronchoscopy on the diagnosis of and outcomes from ventilator-associated pneumonia

BACKGROUND

Ventilator-associated pneumonia (VAP) is a common healthcare-associated infection affecting as many as 27% of mechanically ventilated patients. Ventilator-associated pneumonia is an important source of morbidity and mortality in the surgical intensive care unit (SICU). The optimal diagnostic method for VAP has remained controversial and the role of therapeutic bronchoscopy in the clearance of pulmonary secretions with VAP, in essence source control, remains unknown. Our unit utilizes bronchoscopy inconsistently for these purposes and we chose to evaluate its effectiveness in our patient population with the hypothesis that bronchoscopic diagnosis and therapy results in lower mortality rates and faster clinical resolution.

METHODS

We analyzed retrospectively all patients treated for VAP in a single SICU between September 2003 and December 2011. Patients were divided into groups based upon diagnostic method and receipt of therapeutic bronchoscopy, and were analyzed for differences in time to clinical resolution and mortality.

RESULTS

A total of 360 patients were included in the study, including 493 episodes of VAP. The diagnostic bronchoscopy group had statistically higher APACHE II scores (p=0.02) and fewer days in hospital prior to diagnosis (p=0.02) when compared with the non-invasive diagnosis group. Diagnostic bronchoscopy was associated with shorter length of stay and shorter duration of antibiotics whereas receipt of a therapeutic bronchoscopy was associated with the opposite effects by multivariable analysis.

CONCLUSION

Our hypothesis was disproved and our findings are similar to those found in recent publications. This study supports no definitive conclusions, but further consideration of the role of bronchoscopy is urged in both the diagnosis and treatment of VAP. In our population, bronchoscopy for diagnostic or therapeutic purposes in VAP was not associated with better outcomes. However, differences in baseline characteristics suggest a randomized trial may be needed to answer more completely this question.

The burden of infection in severely injured trauma patients and the relationship with admission shock severity

BACKGROUND

Infection following severe injury is common and has a major impact on patient outcomes. The relationship between patient, injury, and physiologic characteristics with subsequent infections is not clearly defined. The objective of this study was to characterize the drivers and burden of all-cause infection in critical care trauma patients.

METHODS

A prospective cohort study of severely injured adult patients admitted to critical care was conducted. Data were collected prospectively on patient and injury characteristics, baseline physiology, coagulation profiles, and blood product use. Patients were followed up daily for infectious episodes and other adverse outcomes while in the hospital.

RESULTS

Three hundred patients (Injury Severity Score [ISS] >15) were recruited. In 48 hours or less, 29 patients (10%) died, leaving a cohort of 271. One hundred forty-one patients (52%) developed at least one infection. Three hundred four infections were diagnosed overall. Infection and noninfection groups were matched for age, sex, mechanism, and ISS. Infection rates were greater with any degree of admission shock and threefold higher in the most severely shocked cohort (p < 0.01). In multivariate analysis, base deficit (odds ratio [OR], 1.78, 95% confidence interval [CI], 1.48-1.94; p < 0.001) and lactate (OR, 1.36; 95% CI, 1.10-1.69; p = 0.05) were independently associated with the development of infection. Outcomes were significantly worse for the patients with infection. In multivariate logistic regression, infection was the only factor independently associated with multiple-organ failure (p < 0.001; OR, 15.4; 95% CI, 8.2-28.9; r = 0.402), ventilator-free days (p < 0.001; β, -4.48; 95% CI, -6.7 to -2.1; r = 0.245), critical care length of stay (p < 0.001; β, 13.2; 95% CI, 10.0-16.4; r = 0.466), and hospital length of stay (p < 0.001; β, 31.1; 95% CI, 24.0-38.2; r = 0.492).

CONCLUSION

Infectious complications are a burden for severely injured patients and occur early in the critical care stay. Severity of admission shock was predictive of infection and represents an opportunity for interventions to improve infectious outcomes. The incidence of infection may also have utility as an end point for clinical trials in trauma hemorrhage given the relationship with patient-experienced outcomes.

LEVEL OF EVIDENCE

Prognostic/epidemiologic study, level II.

Short- vs long-duration antibiotic regimens for ventilator-associated pneumonia: a systematic review and meta-analysis

BACKGROUND

We performed a systematic review and meta-analysis of short- vs long-duration antibiotic regimens for ventilator-associated pneumonia (VAP).

METHODS

We searched PubMed and Cochrane Central Registry of Controlled Trials. Four randomized controlled trials (RCTs) comparing short (7-8 days) with long (10-15 days) regimens were identified. Primary outcomes included mortality, antibiotic-free days, and clinical and microbiologic relapses. Secondary outcomes included mechanical ventilation-free days, duration of mechanical ventilation, and length of ICU stay.

RESULTS

All RCTs included mortality data, whereas data on relapse and antibiotic-free days were provided in three and two out of four RCTs, respectively. No difference in mortality was found between the compared arms (fixed effect model [FEM]: OR = 1.20; 95% CI, 0.84-1.72; P = .32). There was an increase in antibiotic-free days in favor of the short-course treatment with a pooled weighted mean difference of 3.40 days (random effects model: 95% CI, 1.43-5.37; P &lt; .001). There was no difference in relapses between the compared arms, although a strong trend to lower relapses in the long-course treatment was observed (FEM: OR = 1.67; 95% CI, 0.99-2.83; P = .06). No difference was found between the two arms regarding the remaining outcomes. Sensitivity analyses yielded similar results.

CONCLUSIONS

Short-course treatment of VAP was associated with more antibiotic-free days. No difference was found regarding mortality and relapses; however, a strong trend for fewer relapses was observed in favor of the long-course treatment, being mostly driven by one study in which the observed relapses were probably more microbiologic than clinical. Additional research is required to elucidate the issue.

The impact of antimicrobial resistance and aging in VAP outcomes: experience from a large tertiary care center

Background

Ventilator associated pneumonia (VAP) is a serious infection among patients in the intensive care unit (ICU).

Methods

We reviewed the medical charts of all patients admitted to the adult intensive care units of the Massachusetts General Hospital that went on to develop VAP during a five year period.

Results

200 patients were included in the study of which 50 (25%) were infected with a multidrug resistant pathogen. Increased age, dialysis and late onset (≥5 days from admission) VAP were associated with increased incidence of resistance. Multidrug resistant bacteria (MDRB) isolation was associated with a significant increase in median length of ICU stay (19 vs. 16 days, p = 0.02) and prolonged duration of mechanical ventilation (18 vs. 14 days, p = 0.03), but did not impact overall mortality (HR 1.12, 95% CI 0.51–2.46, p = 0.77). However, age (HR 1.04 95% CI 1.01–1.07, p = 0.003) was an independent risk factor for mortality and age ≥65 years was associated with increased incidence of methicillin-resistant Staphylococcus aureus (MRSA) infections (OR 2.83, 95% CI 1.27–6.32, p = 0.01).

Conclusions

MDRB-related VAP is associated with prolonged ICU stay and mechanical ventilation. Interestingly, age ≥ 65 years is associated with MRSA VAP.