Canadian Critical Care Trials Group. A randomized trial of diagnostic techniques for ventilator-associated pneumonia

Ventilator-associated pneumonia in trauma patients is associated with lower mortality: results from EU-VAP study

BACKGROUND

Differences in trauma patients developing ventilator-associated pneumonia (VAP) are described regarding etiology and risk factors associated. We aim to describe the differences in outcomes in trauma and nontrauma patients with VAP.

METHODS

A prospective, observational study conducted in 27 intensive care units from nine European countries. We included patients requiring invasive mechanical ventilation for >48 hours who developed VAP. Logistic regression model was used to assess the factors independently associated with mortality in trauma patients with VAP.

RESULTS

A total of 2,436 patients were evaluated; 465 developed VAP and of these 128 (27.5%) were trauma patients. Trauma patients were younger than nontrauma (45.3 ± 19.4 vs. 61.1 ± 16.7, p < 0.0001). Nontrauma had higher simplified acute physiology score II compared with trauma patients (45.5 ± 16.3 vs. 41.1 ± 15.2, p = 0.009). Most prevalent pathogens in trauma patients with early VAP were Enterobacteriaceae spp. (46.9% vs. 27.8%, p = 0.06) followed by methicillin-susceptible Staphylococcus aureus (30.6% vs. 13%, p = 0.03) and then Haemophilus influenzae (14.3% vs. 1.9%, p = 0.02), and the most prevalent pathogen in late VAP was Acinetobacter baumannii (12.2% vs. 44.4%, p < 0.0001). Mortality was higher in nontrauma patients than in trauma patients (42.6% vs. 17.2%, p < 0.001, odds ratio [OR] = 3.55, 95%CI = 2.14-5.88). A logistic regression model adjusted for sex, age, severity of illness at intensive care unit admission, and sepsis-related organ failure assessment score at the day of VAP diagnosis confirmed that trauma was associated with a lower mortality compared with nontrauma patients (odds ratio [OR] = 0.37, 95%CI = 0.21-0.65).

CONCLUSIONS

Trauma patients developing VAP had different demographic characteristics and episodes of etiology. After adjustment for potential confounders, VAP episodes in trauma patients are associated with lower mortality when compared with nontrauma patients.

The "fever workup" and respiratory culture practice in critically ill trauma patients

PURPOSE

Fever and leukocytosis (FAL) in critically ill patients often triggers a "workup" that includes a respiratory secretion culture (RCx). We evaluated our respiratory culture practice associated with FAL. We hypothesized that FAL would be associated with a RCx, but would not be associated with a positive culture or treating a respiratory infection in critically injured patients during their first 14 intensive care unit (ICU) days.

MATERIALS AND METHODS

An 18-month retrospective analysis was performed on consecutive ICU trauma patients admitted for 2 days or more to a level I trauma center. Data collected included demographics, injuries, RCxs (bronchoalveolar lavage or tracheal aspirate), maximum daily temperature, and a daily leukocyte count during the first 14 ICU days.

RESULTS

A total of 510 patients with a mean age of 49 and injury severity score of 19 were evaluated for a total of 3839 patient-days. Two hundred eleven patients had 489 RCxs obtained (2.4 RCxs/patient); 94 (19%) were obtained on consecutive days. Obtaining a RCx was associated with fever (relative risk, 4.8; 95% confidence interval, 4.1-5.8) and the combination of FAL (relative risk, 2.6; 95% confidence interval, 2.2-3.1), but not leukocytosis alone. Fever, leukocytosis, or FAL did not predict a positive RCx. One hundred twenty-eight patients were treated for a respiratory infection. Treatment of respiratory infections was contrary to the RCx results 24% of the time. The sensitivity and specificity of a positive RCx being associated with respiratory infection were 97% and 46%, respectively.

CONCLUSIONS

Fever and leukocytosis were associated with the decision to obtain RCxs but were not associated with positive RCxs in our ICU practice. Respiratory secretion culture results had a low specificity and did not consistently impact treatment decisions. Factors other than fever and leukocytosis alone should influence the decision to obtain RCxs during the first 14 days in the ICU after trauma.

Recognition and prevention of nosocomial pneumonia in the intensive care unit and infection control in mechanical ventilation

Nosocomial pneumonia (NP) is a difficult diagnosis to establish in the critically ill patient due to the presence of underlying cardiopulmonary disorders (e.g., pulmonary contusion, acute respiratory distress syndrome, atelectasis) and the nonspecific radiographic and clinical signs associated with this infection. Additionally, the classification of NP in the intensive care unit setting has become increasingly complex, as the types of patients who develop NP become more diverse. The occurrence of NP is especially problematic as it is associated with a greater risk of hospital mortality, longer lengths of stay on mechanical ventilation and in the intensive care unit, a greater need for tracheostomy, and significantly increased medical care costs. The adverse effects of NP on healthcare outcomes has increased pressure on clinicians and healthcare systems to prevent this infection, as well as other nosocomial infections that complicate the hospital course of patients with respiratory failure. This manuscript will provide a brief overview of the current approaches for the diagnosis of NP and focus on strategies for prevention. Finally, we will provide some guidance on how standardized or protocolized care of mechanically ventilated patients can reduce the occurrence of and morbidity associated with complications like NP.

[Intrapulmonary inflammatory response in critically ill patients with pneumonia]

OBJECTIVE

to evaluate the relationship between the microbiology result and cytokine expression in bronchoalveolar lavage (BAL).

DESIGN

An observational, prospective study.

SETTING

a 17-bed medical and surgical intensive care unit.

PATIENTS

Mechanically-ventilated patients with suspected pneumonia admitted to the ICU during a 27-month time period were consecutively enrolled.

INTERVENTIONS

BAL was performed with 150ml sterile isotonic saline solution in three aliquots of 50ml. Local anesthetics were not used during the procedure. A BAL sample was processed for a microbiologic quantitative culture and BAL cytokines IL-6, IL 8, TNFα, granulocyte colony-stimulating factor (G-CSF) and granulocyte-monocyte colony-stimulating factor (GM-CSF) were measured.

MAIN VARIABLES OF INTEREST

age, APACHE II score within the first 24 hours of admission, time on mechanical ventilation, ICU length of stay, mortality, previous antibiotic therapy, isolated bacteria and cytokines concentration were analyzed.

RESULTS

fifty-nine consecutive patients were included, and most of the patients (79.7%) had prior antibiotic therapy. Twenty-two patients (37.2%) had a positive BAL. In the group of patients with positive BAL, the TNFα concentration was significantly higher in the group of patients with positive BAL than in the BAL negative group.

CONCLUSIONS

there is a significant correlation between the microbiology result and the TNFα concentration in the BAL fluid. In mechanically-ventilated patients, TNFα in BAL has been associated with positive cultures despite prior antibiotic therapy.

The Impact of Qualitative Respiratory Cultures on Mortality in Critically III Patients with Hospital-Acquired Pneumonia

This retrospective cohort study evaluated differences in all-cause mortality associated with quantitative versus qualitative cultures in critically ill patients with suspected hospital-acquired pneumonia (HAP). Patients were included if lower respiratory tract (LRT) cultures were obtained and were stratified by culture strategy: invasive (bronchial alveolar lavage [BAL] or nonbronchoscopic BAL) or noninvasive (endotracheal tube aspirate or sputum culture). Mortality data and secondary endpoints were compared between groups. A total of 113 patients met inclusion criteria (invasive = 72, noninvasive = 41). No significant difference in all-cause mortality was detected between the groups (37.5% and 31.7%, respectively; P = 0.54). Secondary endpoints were similar; however, patients in the invasive group had greater mean total antibiotic days of therapy compared to the noninvasive group (21.2 ± 13.5 days vs 15.5 ± 8.3 days, P = 0.01). The present study suggests that using invasive methods to obtain LRT cultures in critically ill patients with suspected HAP did not offer a detectable benefit in mortality or clinical outcomes when compared to noninvasive diagnostic methods.

Prevention, diagnosis, therapy and follow-up care of sepsis: 1st revision of S-2k guidelines of the German Sepsis Society (Deutsche Sepsis-Gesellschaft e.V. (DSG)) and the German Interdisciplinary Association of Intensive Care and Emergency Medicine (Deutsche Interdisziplinäre Vereinigung für Intensiv- und Notfallmedizin (DIVI))

Practice guidelines are systematically developed statements and recommendations that assist the physicians and patients in making decisions about appropriate health care measures for specific clinical circumstances taking into account specific national health care structures. The 1^st revision of the S-2k guideline of the German Sepsis Society in collaboration with 17 German medical scientific societies and one self-help group provides state-of-the-art information (results of controlled clinical trials and expert knowledge) on the effective and appropriate medical care (prevention, diagnosis, therapy and follow-up care) of critically ill patients with severe sepsis or septic shock. The guideline had been developed according to the “German Instrument for Methodological Guideline Appraisal” of the Association of the Scientific Medical Societies (AWMF). In view of the inevitable advancements in scientific knowledge and technical expertise, revisions, updates and amendments must be periodically initiated. The guideline recommendations may not be applied under all circumstances. It rests with the clinician to decide whether a certain recommendation should be adopted or not, taking into consideration the unique set of clinical facts presented in connection with each individual patient as well as the available resources.

Clinical course and spectrum of intensive care unit patients reactivating herpes simplex-1 virus: a retrospective analysis

Background:

Herpes simplex-1 virus (HSV-1) reactivation in the respiratory tract is common in intensive care unit (ICU) patients. However, susceptible ICU populations are poorly defined. Clinical recognition of HSV infection of the respiratory tract is difficult and the impact of such reactivation is not understood.

Materials and Methods:

A retrospective analysis of HSV-1 positive patients encountered over a 5-year period at a multispecialty ICU was carried out. HSV-1 was identified in respiratory secretions using a qualitative polymerase chain reaction (PCR) technique. Patient charts were reviewed for clinical features that would typify HSV-1 respiratory involvement, and the morbidity and mortality risks found with HSV-1 respiratory involvement.

Results:

A review of 48 HSV-1 positive ICU patients showed that patients reactivating HSV in the respiratory tract fell into one of the three categories: (1) septic elderly patients with and without ARDS, (2) immunosuppressed patients, especially those receiving high-dose steroids, and (3) post-thoracotomy patients. Abnormalities suggestive of HSV-1 reactivation in the respiratory tract included, haemorrhagic or excessive respiratory secretions, concomitant orofacial herpes (42%), and bronchoscopic abnormalities (hemorrhagic ulcers and mucosal friability) (83%). Twenty eight percent of the HSV-1 infected patients experienced postextubation stridor. HSV-1 reactivation was associated with extended ventilator stays, significant mortality (42%), and ventilator-associated pneumonias (52%).

Conclusions:

Identification of susceptible populations and definition of clinical features of HSV-1 related respiratory disease can enable diagnosis of HSV-1 infection in ICU patients. Although detection by a PCR technique can rapidly diagnose HSV-1 reactivation, prospective studies are required to clarify HSV disease versus mere shedding, and understand the impact of HSV-1 reactivation in hospitalized patients.

Enhanced protein-energy provision via the enteral route in critically ill patients: a single center feasibility trial of the PEP uP protocol

INTRODUCTION

The purpose of this pilot study is to assess the feasibility, acceptability, and safety of a new feeding protocol designed to enhance the delivery of enteral nutrition (EN).

METHODS

In a prospective before and after study, we evaluated a new protocol compared to our standard feeding protocol. Innovative elements of the new protocol included setting daily volume based goals instead of hourly rate targets, initiating motility agents and protein supplements on Day 1, liberalizing the gastric residual volume threshold, and the option to use trophic feeds. Bedside nurses filled out questionnaires to assess the acceptability of the new approach and we assessed patients' nutritional and clinical outcomes.

RESULTS

We enrolled 20 mechanically ventilated patients who stayed in the Intensive Care Unit for more than three days in the before group and 30 such patients in the after group. On a scale where 1 = totally unacceptable and 10 = totally acceptable, 30 nurses rated the new protocol as 7.1 (range 1 to 10) and no incidents compromising patient safety were observed. In the before group, on average, patients received 58.8% of their energy and 61.2% of their protein requirements by EN compared to 67.9% and 73.6% in the after group (P = 0.33 and 0.13). When the subgroup of patients prescribed to receive full volume feeds in the after group were evaluated (n = 18), they received 83.2% and 89.4% of their energy and protein requirements by EN respectively (P = 0.02 for energy and 0.002 for protein compared to the before group). The rates of vomiting, regurgitation, aspiration, and pneumonia were similar between the two groups.

CONCLUSIONS

This new feeding protocol seems to be safe and acceptable to critical care nurses. The adoption of this protocol may be associated with enhanced delivery of EN but further trials are warranted to evaluate its effect on nutritional and clinical endpoints.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01102348.

Microbiogical data, but not procalcitonin improve the accuracy of the clinical pulmonary infection score

OBJECTIVE

Early and adequate treatment of ventilator-associated pneumonia (VAP) is mandatory to improve the outcome. The aim of this study was to evaluate, in medical ICU patients, the respective and combined impact of the Clinical Pulmonary Infection Score (CPIS), broncho-alveolar lavage (BAL) gram staining, endotracheal aspirate and a biomarker (procalcitonin) for the early diagnosis of VAP.

DESIGN

Prospective, observational study

SETTING

A medical intensive care unit in a teaching hospital.

PATIENTS

Over an 8-month period, we prospectively included 57 patients suspected of having 86 episodes of VAP.

INTERVENTION

The day of suspicion, a BAL as well as alveolar and serum procalcitonin determinations and evaluation of CPIS were performed.

MEASUREMENTS AND MAIN RESULTS

Of 86 BAL performed, 48 were considered positive (cutoff of 10(4) cfu ml(-1)). We found no differences in alveolar or serum procalcitonin between VAP and non-VAP patients. Including procalcitonin in the CPIS score did not increase its accuracy (55%) for the diagnosis of VAP. The best tests to predict VAP were modified CPIS (threshold at 6) combined with microbiological data. Indeed, both routinely twice weekly performed endotracheal aspiration at a threshold of 10(5) cfu ml(-1) and BAL gram staining improved pre-test diagnostic accuracy of VAP (77 and 66%, respectively).

CONCLUSION

This study showed that alveolar procalcitonin performed by BAL does not help the clinician to identify VAP. It confirmed that serum procalcitonin is not an accurate marker of VAP. In contrast, microbiological resources available at the time of VAP suspicion (BAL gram staining, last available endotracheal aspirate) combined or not with CPIS are helpful in distinguishing VAP diagnosed by BAL from patients with a negative BAL.

Pneumonia

Hospital-acquired pneumonia (HAP) is usually caused by bacterial, viral, or fungal pathogens that occur ≥48 h after hospital admission.^1,2 Overall, more than 80% of HAP episodes are related to invasive airway management (in patients with endotracheal intubation or tracheostomy) with mechanical ventilation, which is known as ventilator-associated pneumonia (VAP).³ VAP is defined as pneumonia developing more than 48 h after intubation and mechanical ventilation. Healthcare-associated pneumonia (HCAP) is part of the continuum of pneumonia, which includes patients who were hospitalized in an acute-care hospital for ≥2 days within 90 days of the infection; resided in a long-term care facility; received recent intravenous antibiotic therapy, chemotherapy, or wound care within the past 30 days of the current infection; or attended a hospital or hemodialysis clinic.^1,2 Although this document focuses more on HAP and VAP, many of the principles are also relevant to the management of HCAP. HAP, VAP, and HCAP are the second most common nosocomial infections after urinary tract infection, but are the leading causes of mortality due to hospital-acquired infections.^4,5

[Diagnosis and causal treatment of sepsis]

The high mortality and morbidity of severe sepsis and septic shock had not been reduced during the two recent decades, despite a number of advances in the field of supportive and adjunctive sepsis therapies. The reason might be that important steps towards overcoming of sepsis - early diagnosis, the surgical resection of the infectious focus and an adequate antibiotic treatment - at present are still suboptimal and have to be improved. However, worldwide growing resistances of pathogens against the common antibiotics are detected. In opposite, no major progress in the development of new antibiotics, mainly for the treatment of Gram-negative non-fermenter infections like Pseudomonas aeruginosa, can be predicted for the next years. Therefore, sepsis treatment must be focused on prevention of infection, and on an optimised application of current antibiotic substances. The key factors are a broad, high dose, and early applicated initial treatment, a de-escalation strategy according to the clinical course supported by the application of novel molecular markers, and - with exceptions - a limitation of treatment to 7 to 10 days. A closer cooperation between microbiologists, infection control specialists and clinical infectious disease consultants may be a key factor to overcome the raising problems in the future.

The Problems Diagnosing Ventilator-Associated Pneumonia

Ventilator-associated pneumonia (VAP) is the most common healthcare-associated infection in the intensive care unit. Clinical, radiological and microbiological criteria are used to make the diagnosis, but there is no consensus definition, as no individual criterion or combination of criteria offer sufficient diagnostic accuracy to support their sole use in defining VAP. Neither invasive bronchoscopic sampling nor less invasive quantitative tracheal aspirate, conveys an advantage when making the microbiological diagnosis of VAP. Of the scoring systems and definitions presently in use, the Clinical Pulmonary Infection Score (CPIS) has been shown to be prone to inter-observer variability; the US Centers for Disease Control (CDC) National Healthcare Safety Network (NHSN) definition relies heavily on subjective clinical criteria, and the Hospitals in Europe Link for Infection Control through Surveillance (HELICS) criteria employ similarly subjective clinical criteria with five different possibilities for microbiological diagnosis. The use of these different diagnostic methods leads to marked variation in the reported incidence of VAP. Clinical practice requires an objective and transferable definition for VAP so that we can improve the reporting, monitoring and treatment of VAP.

Approach to the febrile patient in the ICU

Fever is a normal adaptive brain response to infectious and noninfectious causes involving a cytokine-mediated response, the generation of acute phase reactants, and the activation of numerous physiologic, endocrinologic and immunologic systems. Ninety percent of patients with severe sepsis in the intensive care unit (ICU) will experience fever during their hospitalization, while the half of the new detected febrile episodes are of noninfectious origin. In the ICU, fever should be treated in cardiorespiratory and neurosurgical patients and in those in whom temperature exceeds 40 degrees C (104 degrees F). Antipyretic therapy must be justified regardless of the metabolic cost (if fever exceeds its physiologic benefit), the result (if the symptomatic relief adversely affects the course of the febrile illness) and the side effects.

[Bacterial infections in critically ill patients: review of studies published between 2006 and 2008]

A systematic revision of medical publications between 2006 and 2008 regarding bacterial infections that affect the critical patients was performed. Four subjects were selected: Community-acquired pneumonia, ventilator-associated pneumonia, catheter-related bloodstream infection and new antimicrobial treatments. When dealing with community-acquired pneumonia and due to the absence of completely reliable standards, it is necessary to follow the locally adapted guidelines of clinical practice, to identify patients related to the health-care system and admit patients to the ICU in accordance with the criteria. Regarding the etiological diagnosis of ventilator-associated pneumonia, any microbiological information available must be used. Due to the risk of multidrug bacteria, combined empiric therapy should be initiated immediately and then mono-therapy adjusted to the antibiogram should be established. Already established measures for mechanical ventilation associated pneumonia and catheter-related bacteriemias, which have been effective, should be implemented. The empirical treatment of catheter-related bacteremia must be directed towards the most probable pathogens according to the puncture site. The most recently sold antibiotics are basically directed towards multidrug gram positive resistant bacteria. However, for the treatment of gram negative resistant bacilli, the use of the new antimicrobials must be combined with a new evaluation of the antibiotics that have been used for years and the possibility of choosing different administration forms.

Diagnosis of ventilator-associated pneumonia

INTRODUCTION

Ventilator-associated pneumonia (VAP) is difficult to diagnose. Recent data suggest quantitative endotracheal aspirate (ETA) may be noninferior diagnostically to quantitative bronchoalveolar lavage (BAL). We hypothesized this would be the case.

METHODS

Blind quantitative ETA and BAL were performed on 150 consecutive ventilated patients with suspected VAP in a prospective single-centre medical intensive care unit study over a 2-year inclusion period. Patients were either antibiotic-naive or antibiotic-free for 72 hours. Diagnostic yield, Gram stain and culture results, and impact on antibiotic therapy were assessed. The independent impact of a positive BAL or ETA result on ventilator settings and 28-day mortality was calculated. The BAL/ETA safety was assessed hemodynamically.

RESULTS

Bronchoalveolar lavage had significantly higher diagnostic yield (49.3% vs 34.0%, P = .01), more frequent impact on antibiotic therapy (usually de-escalation) (48.0% vs 32.7%, P = .01), and greater sensitivity (64.1% vs 42.6%, P = .0003) than ETA. There was moderate intertest agreement and no difference in specificity and positive and negative predictive values. A positive BAL or ETA result did not independently alter the frequency of ventilator changes or 28-day mortality. Both procedures were well tolerated.

CONCLUSION

Quantitative BAL is safe and has greater diagnostic utility than ETA for VAP facilitates de-escalation. This study provides support for quantitative BAL in VAP diagnosis.

Hospital-acquired pneumonia: pathophysiology, diagnosis, and treatment

Hospital-acquired pneumonia (HAP) is one of the most common causes of nosocomial infection, morbidity, and mortality in hospitalized patients. Many patient- and disease-specific factors contribute to the pathophysiology of HAP, particularly in the surgical population. Risk-factor modification and inpatient prevention strategies can have a significant impact on the incidence of HAP. While the best diagnostic strategy remains a subject of some debate, prompt and appropriate antimicrobial therapy in patients suspected of having HAP has been shown to significantly decrease mortality. Because the pathogens responsible for HAP are frequently more virulent and have greater resistance to commonly used antimicrobials than other pathogens, clinicians must have knowledge of the resistance patterns at their institutions to choose appropriate therapy.

Ventilator-associated infection

PURPOSE OF REVIEW

Ventilator-associated pneumonia (VAP) is the most serious and controversial of the infections of the critically ill patient. The accuracy of standard methods of diagnosis remains under constant scrutiny, and at the same time there is increasing debate about whether it is a preventable disease. This review focuses on the pathophysiology of respiratory tract infection in the ventilated patient, and how the latest advances have grown from our current understanding of its pathogenesis.

RECENT FINDINGS

Data from many recent investigations have focused on the role of proximal airway infection, ventilator-associated tracheobronchitis (VAT), in respiratory tract infection. The goals of recent trials include reducing the morbidity associated with the progression of airway colonization to VAT or with the progression of VAT to VAP. Continuous subglottic secretion suctioning, innovative types of endotracheal tubes and targeted therapy for VAT in recent investigations have shown promise in improving clinical outcomes in the critically ill patient. However, even with diligent attention to all the modifiable risk factors for respiratory infection, complete elimination of VAT and VAP remains unlikely. As long as a patient requires an endotracheal tube that disturbs airway integrity, host defenses will be impaired, and resistant virulent organisms that result from our liberal use of systemic antibiotics will continue to challenge critical care specialists.

SUMMARY

This review will focus on: the current understanding of the pathogenesis of VAT and VAP, modifiable risk factors and new approaches to treatment, and bacterial resistance challenges.

[Bronchoalveolar lavage for diagnosing pneumonia in mechanically ventilated patients]

OBJECTIVE

To evaluate the diagnostic role of bronchoalveolar lavage (BAL) in mechanically ventilated patients with suspected pneumonia and to describe the clinical outcome in the different kinds of pneumonia in critically ill patients.

DESIGN

Descriptive study.

SETTING

A 17-bed medical and surgical intensive care unit.

PATIENTS

Mechanically ventilated patients admitted to the ICU from November 2003 to March 2006 with suspected pneumonia who underwent bronchoscopy with BAL.

INTERVENTIONS

BAL was performed by fiberoptic bronchoscopy with three aliquots of 50 ml sterile normal saline. Recovered BAL fluid was pro-cessed for microbiologic analysis.

MAIN VARIABLES OF INTEREST

Age, APACHE II score within the first 24 hours of admission, time on mechanical ventilation, ICU length of stay, mortality, and isolated bacteria were analyzed.

RESULTS

A total of 96 cases of suspected pneumonia with BAL were recruited, including 4 groups: community associated pneumonia (CAP), 12 cases, early-onset ventilator-associated pneumonia (VAP), 26 cases, late-onset ventilator-associated pneumonia, 43 cases, and immunocompromised patients, 15 cases. BAL was positive (> 10000 ufc/ml) in 40 (41.7%) patients (2, 16, 17 and 5 patients with CAP, early-onset VAP, late-onset VAP and immunocompromised, respectively). Mortality was 33.3%, 26.9%, 25.6% and 73.3% in CAP, early-onset VAP, late-onset VAP and immunocompromised patients respectively.

CONCLUSIONS

The low incidence of positive BAL in the CAP group supports using BAL only for particularly severe, selected cases. Mortality was very high in the immunocompromised patients. In the light of our personal experience, BAL is most useful in the diagnosis of pneumonia in the group of patients with VAP.

Epidemiology of ventilator-associated pneumonia in a long-term acute care hospital

OBJECTIVE

To characterize the epidemiology and microbiology of ventilator-associated pneumonia (VAP) in a long-term acute care hospital (LTACH).

DESIGN

Retrospective study of prospectively identified cases of VAP.

SETTING

Single-center, 207-bed LTACH with the capacity to house 42 patients requiring mechanical ventilation, evaluated from April 1, 2006, through January 31, 2008.

METHODS

Data on the occurrence of VAP were collected prospectively as part of routine infection surveillance at Radius Specialty Hospital. After March 2006, Radius Specialty Hospital implemented a bundle of interventions for the prevention of VAP (hereafter referred to as the VAP-bundle approach). A case of VAP was defined as a patient who required mechanical ventilation at Radius Specialty Hospital for at least 48 hours before any symptoms of pneumonia appeared and who met the Centers for Disease Control and Prevention criteria for VAP. Sputum samples were collected from a tracheal aspirate if there was clinical suspicion of VAP, and these samples were semiquantitatively cultured.

RESULTS

During the 22-month study period, 23 cases of VAP involving 19 patients were associated with 157 LTACH admissions (infection rate, 14.6%), corresponding to a rate of 1.67 cases per 1,000 ventilator-days, which is a 56% reduction from the VAP rate of 3.8 cases per 1,000 ventilator-days reported before the implementation of the VAP-bundle approach (P< .001). Microbiological data were available for 21 (91%) of 23 cases of VAP. Cases of VAP in the LTACH were frequently polymicrobial (mean number +/- SD, 1.78+/-1.0 pathogens per case of VAP), and 20 (95%) of 21 cases of VAP had at least 1 pathogen (Pseudomonas species, Acinetobacter species, gram-negative bacilli resistant to more than 3 antibiotics, or methicillin-resistant Staphylococcus aureus) cultured from a sputum sample. LTACH patients with VAP were more likely to have a neurological reason for ventilator dependence, compared with LTACH patients without VAP (69.6% of cases of VAP vs 39% of cases of respiratory failure; P= .014). In addition, patients with VAP had a longer length of LTACH stay, compared with patients without VAP (median length of stay, 131 days vs 39 days; P= .002). In 6 (26%) of 23 cases of VAP, the patient was eventually weaned from use of mechanical ventilation. Of the 19 patients with VAP, 1 (5%) did not survive the LTACH stay.

CONCLUSIONS

The VAP rate in the LTACH is lower than the VAP rate reported in acute care hospitals. Cases of VAP in the LTACH were frequently polymicrobial and were associated with multidrug-resistant pathogens and increased length of stay. The guidelines from the Centers for Disease Control and Prevention that are aimed at reducing cases of VAP appear to be effective if applied in the LTACH setting.

Evaluation of a 24-hour emergency bronchoscopy service in a tertiary care hospital

BACKGROUND

Flexible bronchoscopy has become an important diagnostic and therapeutic tool for the management of patients with various diseases of the chest. Availability of a 24-hour bronchoscopy service equipped with experienced personnel is becoming increasingly important especially for intensive care patients. However, such services have been implemented only in a few medical centres. The aim of this study was to evaluate the usage of a 24-hour emergency service in a large university hospital with a 1 year prospective analysis of emergency bronchoscopy service in a tertiary care centre.

METHODS

Frequencies, indications and efficiency of therapeutic interventions were evaluated after each bronchoscopy using a specially designed questionnaire. All bronchoscopies were performed as emergency procedures out of operational schedule. A total of 614 emergency bronchoscopies were performed, 88% of them in intensive care units.

RESULTS

The vast majority (84.5%) of the procedures were necessary for therapeutic interventions; that is, atelectasis, airway secretion, aspiration or bronchopulmonary bleeding. According to prespecified criteria, 37.6% (n = 195) of therapeutic procedures were assessed as 'very helpful' and 3.9% (n = 20) as 'life saving'. Diagnostic bronchoscopies were performed mainly to collect airway material for microbiological evaluations in immunocompromised patients. In these cases, the diagnostic yield was approximately 50%.

CONCLUSION

The availability of a 24-hour bronchoscopy service has been found to improve patient care and was occasionally considered life saving. Thus, comparable services should be made more widely available.

Bile acid aspiration in suspected ventilator-associated pneumonia

AIMS

The aims of this study were to measure the levels of bile acids in patients with suspected ventilator-associated pneumonia (VAP) and provide a possible pathway for neutrophilic inflammation to explain its proinflammatory effect on the airway.

METHODS

Bile acid levels were measured by spectrophotometric enzymatic assay, and liquid chromatography mass spectrometry was used to quantify the major bile acids. Alveolar cells were grown on modified air-liquid interface culture inserts, and bile acids were then employed to stimulate the cells. Reverse transcriptase polymerase chain reaction and Western blots were used to determine the involved gene expression and protein levels.

RESULTS

The mean (+/- SE) concentration of total bile acids in tracheal aspirates was 6.2 +/- 2.1 and 1.1 +/- 0.4 mumol/L/g sputum, respectively, for patients with and without VAP (p < 0.05). The interleukin (IL)-8 level was significantly higher in the VAP group (p < 0.05). The major bile acid, chenodeoxycholic acid, stimulated alveolar epithelial cells to increase IL-8 production at both the messenger RNA and protein level through p38 and c-Jun N-terminal kinase (JNK) activation. The selective p38 and JNK inhibitors, as well as dexamethasone, successfully inhibited IL-8 production.

CONCLUSION

These data suggest that early intervention to prevent bile acid aspiration may reduce the intensity of neutrophilic inflammation in intubated and mechanically ventilated patients in the ICU.

[Ventilator-associated pneumonia]

Ventilator-associated pneumonia (VAP) is the most common nosocomial infection in critical care medicine and has been shown to be an independent risk factor for mortality. However, ventilator induced lung injury itself is probably only a minor factor predisposing to VAP. In contrast, invasive ventilation using an endotracheal tube is obviously a more important measure. Thus, microaspiration of potentially infectious secretion from the oropharynx into the trachea along the tube has been suggested to be the most critical pathophysiological event in the process of VAP development. Accordingly, non-invasive ventilation provides a decreased risk of VAP. Therefore, all measures aimed at averting microaspiration or shorten the duration of mechanical ventilation are appropriate to prevent VAP. Moreover, oropharyngeal decontamination may be helpful by reducing bacterial colonisation. Effectiveness of therapy depends on early treatment and therefore requires early diagnosis. With this aim combined clinical, radiologic, and microbiological parameters should be taken into account. Adequate antimicrobial therapy in due consideration for individual risk factors and local antibiotic resistance is the most important therapeutic measure.

Investigator-led clinical research consortia: the Canadian Critical Care Trials Group

Advances in the care of critically ill patients are dependent upon rigorous clinical research undertaken to characterize natural history and risk factors, and determine optimal approaches to the management of the diseases of the critically ill patient. The Canadian Critical Care Trials Group (CCCTG) was formed in 1989 to foster such research. It has grown to become a national, multidisciplinary organization with more than 100 members, and more than 3 dozen active research programs. Its members have been highly successful in obtaining funding for, completing, and publishing well-designed studies that have informed international practice in areas such as transfusion, stress ulcer prophylaxis, long term outcomes from acute respiratory distress syndrome, diagnosis and management of infection in the intensive care unit, and end-of-life care. In the process, the CCCTG has developed a highly effective culture of scientific mentoring, and has served as a model for investigator-led critical care research groups around the world. This review summarizes the history, activities, approaches, and challenges of the CCCTG, in the conviction that investigator-led groups such as ours represent the future of intensive care unit-based research.

Strategies to prevent ventilator-associated pneumonia in acute care hospitals

Previously published guidelines are available that provide comprehensive recommendations for detecting and preventing healthcare-associated infections. The intent of this document is to highlight practical recommendations in a concise format designed to assist acute care hospitals in implementing and prioritizing their ventilator-associated pneumonia (VAP) prevention efforts. Refer to the Society for Healthcare Epidemiology of America/Infectious Diseases Society of America “Compendium of Strategies to Prevent Healthcare-Associated Infections” Executive Summary and Introduction and accompanying editorial for additional discussion.

1. Occurrence of VAP in acute care facilities.

a. VAP is one of the most common infections acquired by adults and children in intensive care units (ICUs).

i. In early studies, it was reported that 10%-20% of patients undergoing ventilation developed VAP. More-recent publications report rates of VAP that range from 1 to 4 cases per 1,000 ventilator-days, but rates may exceed 10 cases per 1,000 ventilator-days in some neonatal and surgical patient populations. The results of recent quality improvement initiatives, however, suggest that many cases of VAP might be prevented by careful attention to the process of care.

2. Outcomes associated with VAP

a. VAP is a cause of significant patient morbidity and mortality, increased utilization of healthcare resources, and excess cost.

i. The mortality attributable to VAP may exceed 10%.

ii. Patients with VAP require prolonged periods of mechanical ventilation, extended hospitalizations, excess use of antimicrobial medications, and increased direct medical costs.

Ventilator-associated pneumonia: problems with diagnosis and therapy

The diagnosis of ventilator-associated pneumonia, VAP, is problematic because of a lack of objective tools that are utilized to make an assessment of bacterial-induced lung injury in a heterogeneous group of hosts. Clinical symptoms and signs are used to identify patients that may have a "lung infection". However, the symptoms and signs can be produced by a myriad of other conditions. Recent clinical data also suggests bacterial-induced pathologic processes occur prior to the onset of the symptoms and signs. Utilizing bacterial culture alone, health care practitioners are forced to wait for days for results and will have to order days of empiric antibiotic therapy. Exploratory molecular studies utilizing clone libraries and molecular arrays for microbial identification document the inability of culture-based techniques to even identify all the microbes involved in VAP. These molecular studies also offer evidence that oral flora present in the lungs of patients with VAP, suggesting aspiration of oral secretions and/or biofilms on endotracheal tubes, supply the bacteria for VAP. Much more investigation is needed to determine the optimal timing of antibiotic treatment and which diagnostic molecular methods can be utilized in the ICU.

Management of nosocomial pneumonia on a medical ward: a comparative study of outcomes and costs of invasive procedures

The goal of this study was to compare outcomes and costs of two management strategies for non-ventilator-associated nosocomial pneumonia (NP) in a medical ward. In this single-centre study, NP patients (n = 68) were randomized to receive non-invasive management (NIM) with immediate empirical antibiotic treatment (n = 34), or invasive management (IM) based on protected brush sampling of specimens (n = 34). The economic analysis adopted the hospital's perspective and took into account only direct costs. Baseline characteristics did not differ significantly between the two patient groups. The most frequently isolated organisms were Staphylococcus (25.4%), Streptococcus (23.7%) and Pseudomonas (18.6%) species. The 28-day clinical cure rate did not differ notably between the two groups (NIM, 79.4%; IM, 73.5%). Mortality at 28 days tended to be lower in the NIM group (10.0% vs. 21.8%). Mean antibiotic costs were lower in the IM group (euro194 +/- 355 vs. euro300 +/- 335, p <0.001) but overall management costs were similar (respectively, euro367 +/- 355 and euro346 +/- 363 in the IM and NIM groups, p = 0.08). With respect to both outcome and cost, this study does not support routine management of NP in medical wards using invasive procedures.

Ventilator-Associated Pneumonia; A Concise Review

Ventilator-associated pneumonia (VAP) continues to be the most common nosocomial infection in critically ill patients requiring mechanical ventilation. In this review data was sourced from Medline, the National Institute for Clinical Effectiveness (NICE), study authors and review articles. Development of VAP prolongs length of stay in the intensive care unit and may increase mortality. Although diagnosis is difficult, with little consensus on ideal diagnostic criteria, there is general agreement that rapid and accurate diagnosis of VAP is essential as delayed administration of appropriate antibiotic therapy increases mortality. Implementation of evidence-based strategies for the prevention of VAP may reduce morbidity, mortality and length of stay.

Effect of synbiotic therapy on the incidence of ventilator associated pneumonia in critically ill patients: a randomised, double-blind, placebo-controlled trial

OBJECTIVE

To investigate the effect of enteral Synbiotic 2000 FORTE (a mixture of lactic acid bacteria and fibre) on the incidence of ventilator associated pneumonia (VAP) in critically ill patients.

DESIGN

Prospective, randomised, double blind, placebo controlled trial.

SETTING

Tertiary referral centre, general Adult Intensive Care Unit (ICU).

PATIENTS AND PARTICIPANTS

259 enterally fed patients requiring mechanical ventilation for 48 h or more were enrolled.

INTERVENTION

All patients were enterally fed as per a standard protocol and randomly assigned to receive either synbiotic 2000 FORTE (twice a day) or a cellulose-based placebo for a maximum of 28 days.

MEASUREMENTS AND RESULTS

Treatment group (n = 130) was well matched with placebo group (n = 129) for age (mean 49.5 and 50 years, respectively) and APACHE II score (median 17 for both). Oropharyngeal microbial flora and colonisation rates were unaffected by synbiotics. The overall incidence of VAP was lower than anticipated (11.2%) and no statistical difference was demonstrated between groups receiving synbiotic and placebo in the incidence of VAP (9 and 13%, P = 0.42), VAP rate per 1,000 ventilator days (13 and 14.6, P = 0.91) or hospital mortality (27 and 33%, P = 0.39), respectively.

CONCLUSIONS

Enteral administration of Synbiotic 2000 FORTE has no statistically significant impact on the incidence of VAP in critically ill patients.

Pulmonary complications associated with the treatment of patients with congenital cardiac disease: consensus definitions from the Multi-Societal Database Committee for Pediatric and Congenital Heart Disease

A complication is an event or occurrence that is associated with a disease or a healthcare intervention, is a departure from the desired course of events, and may cause, or be associated with, suboptimal outcome. A complication does not necessarily represent a breech in the standard of care that constitutes medical negligence or medical malpractice. An operative or procedural complication is any complication, regardless of cause, occurring (1) within 30 days after surgery or intervention in or out of the hospital, or (2) after 30 days during the same hospitalization subsequent to the operation or intervention. Operative and procedural complications include both intraoperative/intraprocedural complications and postoperative/postprocedural complications in this time interval. The MultiSocietal Database Committee for Pediatric and Congenital Heart Disease has set forth a comprehensive list of complications associated with the treatment of patients with congenital cardiac disease, related to cardiac, pulmonary, renal, haematological, infectious, neurological, gastrointestinal, and endocrinal systems, as well as those related to the management of anaesthesia and perfusion, and the transplantation of thoracic organs. The objective of this manuscript is to examine the definitions of operative morbidity as they relate specifically to the pulmonary system. These specific definitions and terms will be used to track morbidity associated with surgical and transcatheter interventions and other forms of therapy in a common language across many separate databases. As surgical survival in children with congenital cardiac disease has improved in recent years, focus has necessarily shifted to reducing the morbidity of congenital cardiac malformations and their treatment. A comprehensive list of pulmonary complications is presented. This list is a component of a systems-based compendium of complications that will standardize terminology and thereby allow the study and quantification of morbidity in patients with congenital cardiac malformations. Clinicians caring for patients with congenital cardiac disease will be able to use this list for databases, initiatives to improve quality, reporting of complications, and comparing strategies of treatment.

The utility of the clinical pulmonary infection score

The most common infectious complication in critically ill patients is ventilator-associated pneumonia. Ventilator-associated pneumonia has significant morbidity and mortality, prolongs mechanical ventilation, and extends length of hospitalization. Despite its prevalence and impact, uniform diagnostic standards are lacking. The Centers for Disease Control, American Thoracic Society, and Infectious Diseases Society of America have recommended focus on improving preventive measures, establishing widely available and accurate diagnostic tools, and improving ventilator-associated pneumonia management with length of therapy guidelines. The purpose of this article is to review the evidence supporting the clinical pulmonary infection score as an adjunct to distinguish and detect clinically relevant ventilator-associated pneumonia and its use to guide length of therapy. This score combines clinical diagnostic criteria (tracheal secretion quantification and body temperature) with routinely obtained laboratory data (white blood cell count and oxygenation parameters), radiographic data, and bacteriological culture results. Limitations of clinical pulmonary infection score will be discussed.

The Fourth National Institutes of Health Symposium on the Functional Genomics of Critical Injury: Surviving stress from organ systems to molecules

Recent strides in computational biology and high-throughput technologies have generated considerable interest in understanding complex biological systems. The application of these technologies to critical illness and injury offers the potential to define adaptive and maladaptive programs of gene expression induced by infection, shock, trauma, or other inflammatory triggers, and to detect biomarkers and genetic polymorphisms linked to these responses and outcome. A systems biology approach is timely because despite substantial effort, treatment approaches directed at a single mediator or inflammatory pathway have met with little success in altering outcomes of critically ill or injured patients. Highlights from the Fourth National Institute of Health Functional Genomics of Critical Illness and Injury Symposium are described herein, in addition to deliverables for the field identified during panel discussions. Next steps for the community and suggestions for future research are presented.

Blood product transfusion and ventilator-associated pneumonia in trauma patients

BACKGROUND

Ventilator-associated pneumonia (VAP) is the most common nosocomial infection in trauma patients, with a high mortality rate. Blood transfusion has been identified as an independent risk factor for VAP in critically ill patients. Prior studies in trauma are limited by retrospective design, lack of multivariable analyses, and scant data on the timing of transfusion. We examined critically the relation between blood product transfusion and VAP in trauma patients.

METHODS

Prospective observational cohort study of 766 trauma patients admitted to the intensive care unit (ICU), who received mechanical ventilation (MV) for >or= 48 h, and who did not have pneumonia on admission. Late-onset VAP was defined as that occurring >or= 72 h after MV. Only transfusions of red blood cell (RBC) concentrate, fresh-frozen plasma (FFP), or platelets before the onset of VAP were considered. Logistic regression analyses controlled for all variables related significantly to VAP by univariate analysis (sex, Injury Severity Score, and ventilator days and ICU length of stay prior to VAP).

RESULTS

A significantly greater proportion of male patients developed VAP. Patients with VAP had a longer duration of MV: The mean number ventilator days prior to VAP was 11.1 +/- 8.0. Transfusion of blood products was an independent risk factor for VAP, and the risk increased with more units transfused. All blood products were associated with a higher risk of VAP (RBC: odds ratio [OR] 4.41; 95% confidence interval [CI] 1.00, 19.54; p = 0.05; FFP: OR 3.34; 95% CI 1.18, 9.43; p = 0.023; platelets: OR 4.19; 95% CI 1.37, 12.83; p = 0.012).

CONCLUSION

Blood product transfusion is an independent risk factor for VAP in trauma, and the odds ratio is significantly higher (3.34-4.41) than in published studies of other types of ICU patients (1.89). To reduce the incidence of VAP, all efforts to reduce the transfusion of blood products to trauma patients should be implemented.