Detection of nosocomial lung infection in ventilated patients. Use of a protected specimen brush and quantitative culture techniques in 147 patients

Research Bronchoscopies in Critically Ill Research Participants: An Official American Thoracic Society Workshop Report

Bronchoscopy for research purposes is a valuable tool to understand lung-specific biology in human participants. Despite published reports and active research protocols using this procedure in critically ill patients, no recent document encapsulates the important safety considerations and downstream applications of this procedure in this setting. The objectives were to identify safe practices for patient selection and protection of hospital staff, provide recommendations for sample procurement to standardize studies, and give guidance on sample preparation for novel research technologies. Seventeen international experts in the management of critically ill patients, bronchoscopy in clinical and research settings, and experience in patient-oriented clinical or translational research convened for a workshop. Review of relevant literature, expert presentations, and discussion generated the findings presented herein. The committee concludes that research bronchoscopy with bronchoalveolar lavage in critically ill patients on mechanical ventilation is valuable and safe in appropriately selected patients. This report includes recommendations on standardization of this procedure and prioritizes the reporting of sample management to produce more reproducible results between laboratories. This document serves as a resource to the community of researchers who endeavor to include bronchoscopy as part of their research protocols and highlights key considerations for the inclusion and safety of research participants.

From bedside to bedside: how iterative clinical research influenced the diagnosis and management of pneumonia at the Elvis Presley Trauma Center

Ventilator-associated pneumonia is a well-acknowledged complication after hospitalization for injury or surgical emergency. The contribution to the literature on this topic by Dr Timothy Fabian and the Memphis group at the Elvis Presley Trauma Center resulted in the contemporary recognition that the diagnosis and management of pneumonia is an essential component of surgical critical care. During three decades, the Memphis group, under Dr Fabian's leadership, performed numerous clinical studies that led to the publication of over 40 articles concerning the epidemiology, diagnosis, and treatment of pneumonia after injury. The purpose of this review is to survey the consecutive studies from Memphis specifically that led to the development of a clinical pathway that has stood the test of time. Examination of the research output during this period provides a case study in how bedside clinical research can inform clinical practice and is a model for applied science in the intensive care unit.

Which Biomarkers Can Be Used as Diagnostic Tools for Infection in Suspected Sepsis?

The diagnosis of infection in patients with suspected sepsis is frequently difficult to achieve with a reasonable degree of certainty. Currently, the diagnosis of infection still relies on a combination of systemic manifestations, manifestations of organ dysfunction, and microbiological documentation. In addition, the microbiologic confirmation of infection is obtained only after 2 to 3 days of empiric antibiotic therapy. These criteria are far from perfect being at least in part responsible for the overuse and misuse of antibiotics, in the community and in hospital, and probably the main drive for antibiotic resistance. Biomarkers have been studied and used in several clinical settings as surrogate markers of infection to improve their diagnostic accuracy as well as in the assessment of response to antibiotics and in antibiotic stewardship programs. The aim of this review is to provide a clear overview of the current evidence of usefulness of biomarkers in several clinical scenarios, namely, to diagnose infection to prescribe antibiotics, to exclude infection to withhold antibiotics, and to identify the causative pathogen to target antimicrobial treatment. In recent years, new evidence with "old" biomarkers, like C-reactive protein and procalcitonin, as well as new biomarkers and molecular tests, as breathomics or bacterial DNA identification by polymerase chain reaction, increased markedly in different areas adding useful information for clinical decision making at the bedside when adequately used. The recent evidence shows that the information given by biomarkers can support the suspicion of infection and pathogen identification but also, and not less important, can exclude its diagnosis. Although the ideal biomarker has not yet been found, there are various promising biomarkers that represent true evolutions in the diagnosis of infection in patients with suspected sepsis.

Predictors of Physician Confidence to Diagnose Pneumonia and Determine Illness Severity in Ventilated Patients. Australian and New Zealand Practice in Intensive Care (ANZPIC II)

The manner in which elements of clinical history, physical examination and investigations influence subjectively assessed illness severity and outcome prediction is poorly understood. This study investigates the relationship between clinician and objectively assessed illness severity and the factors influencing clinician's diagnostic confidence and illness severity rating for ventilated patients with suspected pneumonia in the intensive care unit (ICU).

A prospective study of fourteen ICUs included all ventilated admissions with a clinical diagnosis of pneumonia. Data collection included pneumonia type – community-acquired (CAP), hospital-acquired (HAP) and ventilator-associated (VAP), clinician determined illness severity (CDIS), diagnostic methods, clinical diagnostic confidence (CDC), microbiological isolates and antibiotic use.

For 476 episodes of pneumonia (48% CAP, 24% HAP, 28% VAP), CDC was greatest for CAP (64% CAP, 50% HAP and 49% VAP, P<0.01) or when pneumonia was considered “life-threatening” (84% high CDC, 13% medium CDC and 3% low CDC, P<0.001). “Life-threatening” pneumonia was predicted by worsening gas exchange (OR 4.8, CI 95% 2.3–10.2, P<0.001), clinical signs of consolidation (OR 2.0, CI 95% 1.2–3.2, P<0.01) and the Sepsis-Related Organ Failure Assessment (SOFA) Score (OR 1.1, CI 95% 1.1–1.2, P<0.001). Diagnostic confidence increased with CDIS (OR 16.3, CI 95% 8.4–31.4, P<0.001), definite pathogen isolation (OR 3.3, CI 95% 2.0–5.6) and clinical signs of consolidation (OR 2.1, CI 95% 1.3–3.3, P=0.001). Although the CDIS, SOFA Score and the Simplified Acute Physiologic Score (SAPS II) were all associated with mortality, the SAPS II Score was the best predictor of mortality (P=0.02).

Diagnostic confidence for pneumonia is moderate but increases with more classical presentations. A small set of clinical parameters influence subjective assessment. Objective assessment using SAPS II Scoring is a better predictor of mortality.

The Effect of Blind-Protected Specimen Brush Sampling on Antibiotic Use in Patients with Suspected Ventilator-Associated Pneumonia

The diagnosis of pneumonia in ventilated patients is exceedingly difficult. Although culture of tracheal aspirates have poor diagnostic value they are frequently used to diagnose ventilator-associated pneumonia (VAP). Recently a number of studies have reported on the diagnostic value of “blind” protected specimen brush (B-PSB) sampling in the diagnosis of VAP. B-PSB sampling can readily and safely be performed by respiratory care practitioners (RCPs). The aim of this study was to determine the cost-effectiveness of B-PSB sampling performed by respiratory therapists in patients with suspected VAP. During a 3-month run-in period, patients in our medical intensive care unit (MICU) with suspected VAP were treated based on clinical criteria and tracheal aspirate culture. Following this run-in period the house staff, nurses, and RCPs were prevented from sending tracheal aspirates for culture. All patients suspected of having VAP underwent B-PSB sampling with quantitative culture. The B-PSB sampling was performed by RCPs who had been trained to perform the technique. A PSB with a potential bacterial pathogen concentration greater than 500 CFU/ml was regarded as positive. During the 3-month run-in period 172 patients received mechanical ventilation with an average of 4.9 ±3.1 ventilator days/patient. During this period 79 patients were treated for VAP. During the 3-month study period 160 patients received mechanical ventilation, with an average of 5.1 ± 2.9 ventilator days/patient (NS). Fifty-eight B-PSB samplings were performed in 50 patients for suspected VAP. No complications related to the procedure were reported. No tracheal aspirates were cultured during this time period. Eight patients had positive PSB cultures. Antibiotics were changed in three of these patients based on the PSB results. Thirty-eight courses of antibiotics (in 36 patients) were stopped based on negative PSB results. Twelve cases of VAP were suspected in six patients receiving antibiotics for other reasons. No change in antibiotics were made in these cases based on the negative PSB results. The length of mechanical ventilation was 5.4 ± 3.2 days in the 38 culture-negative patients in whom antibiotics were stopped compared to 8.2 ± 4.7 days in the 8 patients with PSB-positive VAP (NS; p = 0.14). The direct cost savings as a result of discontinuing antibiotics was $9,500. There were additional cost savings due to the reduced number of culture specimens sent to the laboratory (approximately $3,000; taking the $23 cost of the PSB brush into account), with a projected annual cost savings of $50,000. B-PSB sampling is a simple and cost-efficient diagnostic test that can safely be performed by adequately trained RCPs. Furthermore, this study confirms that antibiotics may be safely discontinued in patients with negative quantitative culture results.

Ventilator-Associated Pneumonia: A Review

Ventilator-associated pneumonia is the most frequent intensive care unit (ICU)-related infection in patients requiring mechanical ventilation. In contrast to other ICU-related infections, which have a low mortality rate, the mortality rate for ventilator-associated pneumonia ranges from 20% to 50%. These clinically significant infections prolong duration of mechanical ventilation and ICU length of stay, underscoring the financial burden these infections impose on the health care system. The causes of ventilator-associated pneumonia are varied and differ across different patient populations and different types of ICUs. This varied presentation underscores the need for the intensivist treating the patient with ventilator-associated pneumonia to have a clear knowledge of the ambient microbiologic flora in their ICU. Prevention of this disease process is of paramount importance and requires a multifaceted approach. Once a diagnosis of ventilator-associated pneumonia is suspected, early broad-spectrum antibiotic administration decreases morbidity and mortality and should be based on knowledge of the sensitivities of common infecting organisms in the ICU. De-escalation of therapy, once final culture results are available, is necessary to minimize development of resistant pathogens. Duration of therapy should be based on the patient’s clinical response, and every effort should be made to minimize duration of therapy, thus further minimizing the risk of resistance.

Noninvasive target CT detection and anti-inflammation of MRSA pneumonia with theranostic silver loaded mesoporous silica

Antibiotics resistant MRSA related pneumonia lesions could be detected under CT guidance and controlled using theranostic reported herein.

A national survey of the diagnosis and management of suspected ventilator-associated pneumonia

BACKGROUND

Ventilator-associated pneumonia (VAP) affects up to 20% of patients admitted to intensive care units (ICU). It is associated with increased morbidity, mortality and healthcare costs. Despite published guidelines, variability in diagnosis and management exists, the extent of which remains unclear. We sought to characterise consultant opinions surrounding diagnostic and management practice for VAP in the UK.

METHODS

An online survey was sent to all consultant members of the UK Intensive Care Society (n=∼1500). Data were collected regarding respondents' individual practice in the investigation and management of suspected VAP including use of diagnostic criteria, microbiological sampling, chest X-ray (CXR), bronchoscopy and antibiotic treatments.

RESULTS

339 (23%) responses were received from a broadly representative spectrum of ICU consultants. All respondents indicated that microbiological confirmation should be sought, the majority (57.8%) stating they would take an endotracheal aspirate prior to starting empirical antibiotics. Microbiology reporting services were described as qualitative only by 29.7%. Only 17% of respondents had access to routine reporting of CXRs by a radiologist. Little consensus exists regarding technique for bronchoalveolar lavage (BAL) with the reported volume of saline used ranging from 5 to 500 mL. 24.5% of consultants felt inadequately trained in bronchoscopy.

CONCLUSIONS

There is wide variability in the approach to diagnosis and management of VAP among UK consultants. Such variability challenges the reliability of the diagnosis of VAP and its reported incidence as a performance indicator in healthcare systems. The data presented suggest increased radiological and microbiological support, and standardisation of BAL technique, might improve this situation.

Diagnostic accuracy of pulmonary host inflammatory mediators in the exclusion of ventilator-acquired pneumonia

BACKGROUND

Excessive use of empirical antibiotics is common in critically ill patients. Rapid biomarker-based exclusion of infection may improve antibiotic stewardship in ventilator-acquired pneumonia (VAP). However, successful validation of the usefulness of potential markers in this setting is exceptionally rare.

OBJECTIVES

We sought to validate the capacity for specific host inflammatory mediators to exclude pneumonia in patients with suspected VAP.

METHODS

A prospective, multicentre, validation study of patients with suspected VAP was conducted in 12 intensive care units. VAP was confirmed following bronchoscopy by culture of a potential pathogen in bronchoalveolar lavage fluid (BALF) at >10(4) colony forming units per millilitre (cfu/mL). Interleukin-1 beta (IL-1β), IL-8, matrix metalloproteinase-8 (MMP-8), MMP-9 and human neutrophil elastase (HNE) were quantified in BALF. Diagnostic utility was determined for biomarkers individually and in combination.

RESULTS

Paired BALF culture and biomarker results were available for 150 patients. 53 patients (35%) had VAP and 97 (65%) patients formed the non-VAP group. All biomarkers were significantly higher in the VAP group (p<0.001). The area under the receiver operator characteristic curve for IL-1β was 0.81; IL-8, 0.74; MMP-8, 0.76; MMP-9, 0.79 and HNE, 0.78. A combination of IL-1β and IL-8, at the optimal cut-point, excluded VAP with a sensitivity of 100%, a specificity of 44.3% and a post-test probability of 0% (95% CI 0% to 9.2%).

CONCLUSIONS

Low BALF IL-1β in combination with IL-8 confidently excludes VAP and could form a rapid biomarker-based rule-out test, with the potential to improve antibiotic stewardship.

Predictors of the pathogenicity of methicillin-resistant Staphylococcus aureus nosocomial pneumonia

BACKGROUND AND OBJECTIVE

The clinical characteristics of patients with nosocomial pneumonia (NP) associated with methicillin-resistant Staphylococcus aureus (MRSA) infection are not well characterized.

METHODS

Three hundred and thirty-seven consecutive patients with MRSA isolation from respiratory specimens who attended our hospital between April 2007 and March 2011 were enrolled. Patients characteristics diagnosed with 'true' MRSA-NP were described with regards to clinical, microbiological features, radiological features and genetic characteristics of the isolates. The diagnosis of 'true' MRSA-NP was confirmed by anti-MRSA treatment effects, Gram-staining or bronchoalveolar lavage fluid culture.

RESULTS

Thirty-six patients were diagnosed with 'true' MRSA-NP, whereas 34 were diagnosed with NP with MRSA colonization. Patients with a MRSA-NP had a Pneumonia Patient Outcomes Research Team score of 5 (58.3% vs 23.5%), single cultivation of MRSA (83.3% vs 38.2%), MRSA quantitative cultivation yielding more than 10(6) CFU/mL (80.6% vs 47.1%), radiological findings other than lobar pneumonia (66.7% vs 26.5%), and a history of head, neck, oesophageal or stomach surgery (30.6% vs 11.8%). These factors were shown to be independent predictors of the pathogenicity of 'true' MRSA-NP by multivariate analysis (P < 0.05).

CONCLUSIONS

'True' MRSA-NP shows distinct clinical and radiological features from NP with MRSA colonization.

Ventilator-associated pneumonia is characterized by excessive release of neutrophil proteases in the lung

BACKGROUND

Ventilator-associated pneumonia (VAP) is characterized by neutrophils infiltrating the alveolar space. VAP is associated with high mortality, and accurate diagnosis remains difficult. We hypothesized that proteolytic enzymes from neutrophils would be significantly increased and locally produced inhibitors of human neutrophil elastase (HNE) would be decreased in BAL fluid (BALF) from patients with confirmed VAP. We postulated that in suspected VAP, neutrophil proteases in BALF may help identify "true" VAP.

METHODS

BAL was performed in 55 patients with suspected VAP and in 18 control subjects. Isolation of a pathogen(s) at > 10⁴ colony-forming units/mL of BALF dichotomized patients into VAP (n = 12) and non-VAP (n = 43) groups. Matrix metalloproteinases (MMPs), HNE, inhibitors of HNE, and tissue inhibitors of matrix metalloproteinases (TIMPs) were quantified. Plasminogen activator (PA) activity was estimated by sodium dodecyl sulfate polyacrylamide gel electrophoresis and zymography.

RESULTS

Neutrophil-derived proteases HNE, MMP-8, and MMP-9 were significantly increased in cell-free BALF from patients with VAP as compared with those without VAP (median values: HNE, 2,708 ng/mL vs 294 ng/mL, P < .01; MMP-8, 184 ng/mL vs 5 ng/mL, P < .01; MMP-9, 310 ng/mL vs 11 ng/mL, P < .01). HNE activity was also significantly increased in VAP (0.45 vs 0.01 arbitrary units; P < .05). In contrast, no significant differences were observed for protease inhibitors, TIMPs, or PAs. HNE in BALF, at a cutoff of 670 ng/mL, identified VAP with a sensitivity of 93% and specificity of 79%.

CONCLUSIONS

Neutrophil proteases are significantly elevated in the alveolar space in VAP and may contribute to pathogenesis. Neutrophil proteases appear to have potential in suspected VAP for distinguishing true cases from "non-VAP" cases.

Clinical Aspects of Upper and Lower Respiratory Tract Infections

Respiratory tract infections are among the most common illnesses leading to medical consultation, and are associated with significant mortality. Community-acquired pneumonia is a common illness and, while Streptococcus pneumoniae continues to be the most frequent causative agent, atypical pathogens such as Mycoplasma pneumoniae, Chlamydia pneumoniae and Legionella species are now identified as additional common aetiological agents. Since clinical and roentgenographic features poorly predict the aetiological agent in most cases of community-acquired pneumonia, empirical therapy is generally recommended. Nosocomial pneumonia is the second most common hospital-acquired infection and is associated with significant mortality. Aerobic Gram-negative bacilli and Staphylococcus aureus are the predominant causative pathogens. New techniques to improve the diagnosis of nosocomial pneumonia have been introduced, but their role has not been entirely clarified. Therapy directed toward the most likely pathogens (aerobic Gram-negative species and S. aureus) on an empirical basis is recommended until more specific information is obtained. Acute exacerbations of chronic bronchitis should be treated with antimicrobial therapy directed toward S. pneumoniae, Haemophilus influenzae or Moraxella catarrhalis. Because of the emergence of β-lactamase-producing strains of H. influenzae and M. catarrhalis, the choice of an antimicrobial agent has to be carefully considered. Group A β-haemolytic streptococci are the most common cause of bacterial pharyngitis and penicillin remains the drug of choice. Patients suffering from otitis media and sinusitis are infected with the same organisms as those patients with acute exacerbations of chronic bronchitis and antibacterial choices are therefore similar.

Continuous versus intermittent administration of piperacillin-tazobactam in intensive care unit patients with ventilator-associated pneumonia

BACKGROUND AND AIMS

Ventilator-associated pneumonia (VAP) is one of the most common Intensive Care Unit (ICU)-acquired infection. The aim of this study was to compare the clinical outcome of continuous and intermittent administration of piperacillin-tazobactam by serial measurements of the Clinical Pulmonary Infection Score (CPIS).

SUBJECTS AND METHODS

Groups were designed as parallel and the study was designed as quasi-experimental and conducted at a semi-closed ICU between September 2008 and May 2010. Patients received 3.375 g (piperacillin 3 g/tazobactam 0.375 g) either through intermittent infusion every 6 h for 30 min [Intermittent Infusion (II) group; n = 30] or through continuous infusion every 8 h for 4 h [Continuous Infusion (CI) group; n = 31]. CPIS was used to assess the clinical diagnosis and outcome of VAP patients.

RESULTS

Sex, age, Acute Physiology and Chronic Health Evaluation II II score on ICU admission, diagnosis and underlying disease of VAP patients were not significantly different in the CI (n = 31) and II (n = 30) groups. Duration of mechanical ventilation, length of stay, total number of antibiotics used per patient and duration of piperacillin/tazobactam treatment were similar in both groups. Mortality rates of VAP patients were similar between both groups during hospitalization.

CONCLUSION

There was no significant difference in clinical outcomes of patients receiving piperacillin-tazobactam via CI or II when measured by serial CPIS score.

[Should the diagnosis of ventilator associated pneumonia be improved?]

Ventilator associated pneumonia (VAP) is the leading nosocomial infection in intensive care. It is associated with increased ICU and hospital stay, an increased use of antibiotics, and greater hospital costs. The recently launched Pneumonia Zero project (NZ) undoubtedly constitutes a challenge for professionals in the ICU, and has been designed to reduce the high incidence rates described. It is necessary to establish the true incidence, and whether the latter is influenced by the diagnostic method employed. The lack of a reference standard for the microbiological diagnosis of VAP has generated controversy over the diagnostic algorithms to be used, with the distinction of two strategies: a noninvasive or clinical strategy based on upper respiratory tract cultures, and an invasive method based on the use of quantitative cultures of samples from the lower respiratory tract obtained by bronchoscopic techniques. Despite the recommendations of scientific societies, which do not justify the use of qualitative tracheal aspirates in the microbiological diagnosis of VAP, this method is still routinely used. This study underscores the need to stop using qualitative tracheal aspirates as a routine diagnostic method for VAP, recommending the use of bronchoscopic techniques or quantitative tracheal aspirates.

Comparison of bronchoscopic and non-bronchoscopic techniques for diagnosis of ventilator associated pneumonia

Background:

The diagnosis of ventilator associated pneumonia (VAP) remains a challenge because the clinical signs and symptoms lack both sensitivity and specificity and the selection of microbiologic diagnostic procedure is still a matter of debate.

Aims and Objective:

To study the role of various bronchoscopic and non-bronchoscopic diagnostic techniques for diagnosis of VAP.

Settings and Design:

This prospective comparative study was conducted in a medical ICU of a tertiary care center.

Materials and Methods:

Twenty-five patients, clinically diagnosed with VAP, were evaluated by bronchoscopic and non-bronchoscopic procedures for diagnosis. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of various bronchoscopic and non-bronchoscopic techniques were calculated, taking clinical pulmonary infection score (CPIS) of ≥6 as reference standard.

Results:

Our study has shown that for the diagnosis of VAP, bronchoscopic brush had a sensitivity, specificity, PPV and NPV of 94.9% [confidence interval (CI): 70.6–99.7], 57.1% (CI: 13.4–86.1), 85% (CI: 61.1–96) and 80% (CI: 21.9–98.7), respectively. Bronchoscopic bronchoalveolar lavage (BAL) had a sensitivity, specificity, PPV and NPV of 77.8% (CI: 51.9–92.6), 71.8% (CI: 24.1–94), 87.3% (CI: 60.4–97.8) and 55.5% (CI: 17.4–82.6), respectively. Sensitivity, specificity, PPV and NPV for non–bronchoscopic BAL (NBAL) were 83.3% (CI: 57.7–95.6), 71.43% (CI: 24.1–94), 88.2% (CI: 62.3–97.4) and 62.5% (CI: 20.2–88.2), respectively. Endotracheal aspirate (ETA) yield was only 52% and showed poor concordance with BAL (κ-0.351; P-0.064) and NBAL (k-0.272; P-0.161). There was a good microbiologic concordance among different bronchoscopic and non-bronchoscopic distal airway sampling techniques.

Conclusion:

NBAL is an inexpensive, easy, and useful technique for microbiologic diagnosis of VAP. Our findings, if verified, might simplify the approach for the diagnosis of VAP.

Double ECMO in severe ARDS: report of an outstanding case and literature review

We report on a 49-year-old male patient who suffered from severe herpes simplex (HSV) pneumonia after a fall-from-height injury, causing a circumscript type B aortic dissection.The subsequent occurrence of ARDS required a veno-venous ECMO circuit that was upgraded to a veno-arterial system due to further oxygenation deficits. Following continued respiratory deterioration, the ECMO system already in place had to be complemented by a second veno-arterial line. After the onset of recovery and because of a developing of a disseminated intravasal coagulation, the double ECMO circuit was replaced by a pumpless extracorporeal lung assist system (PECLA). The patient recovered completely under systemic virostatic therapy.

Ventilator-associated pneumonia: current status and future recommendations

OBJECTIVE

Ventilator-associated pneumonia (VAP) is a common hazardous complication in ICU patients. The aim of the current review is to give an update on the current status and future recommendations for VAP prevention.

METHODS

This article gives an updated review of the current literature on VAP. The first part briefly reviews pathogenesis and epidemiology while the second includes an in-depth review of evidence-based practice guidelines (EBPG) and new technologies developed for prevention of VAP.

RESULTS

VAP remains a frequent and costly complication of critical illness with a pooled relative risk of 9-27% and mortality of 25-50%. Strikingly, VAP adds an estimated cost of more than $40,000 to a typical hospital admission. An important aetiological mechanism of VAP is gross or micro-aspiration of oropharyngeal organisms around the cuff of the endotracheal tube (ETT) into the distal bronchi. Prevention of VAP is preferable. Preventative measures can be divided into two main groups: the implemen- tation of EBPGs and use of device-based technologies. EBPGs have been authored jointly by the American Thoracic Society and the Infectious Diseases Society of America. The Canadian Critical Care Trials group also published VAP Guidelines in 2008. Their recommendations are detailed in this review. The current device-based technologies include drainage of subglottic secretions, silver coated ETTs aiming to influence the internal bio-layer of the ETT, better sealing of the lower airways with ultrathin cuffs and loops for optimal cuff pressure control.

CONCLUSIONS

EBPG consensus includes: elevation of the head of the bed, use of daily "sedation vacations" and decontamination of the oropharynx. Technological solutions should aim to use the most comprehensive combination of subglottic suction of secretions, optimization of ETT cuff pressure and ultrathin cuffs. VAP is a type of hospital-acquired pneumonia that develops more than 48 h after endotracheal intubation. Its incidence is estimated to be 9-27%, with a mortality of 25-50% [Am J Respir Crit Care Med 171:388-416 (2005), Am J Med 85:499-506 (1988), Chest 122:2115-2121 (2002), Intensive Care Med 35:9-29 (2009)]. The most important target in VAP handling is its prevention. The aim of this article is to review the pathogenesis, epidemiology and the different strategies/technologies for prevention of VAP.

Ventilator-Associated Pneumonia

The area of the alveolar epithelium of the lung is approximately 70 m². This area is constantly in contact with the ambient air and is therefore vulnerable to contamination with airborne microbes and particles of respirable size. Due to the configuration of the respiratory tract, airborne particles having diameters in the range of 0.5-2.0 μ can reach and deposit in the terminal part of the tracheobronchial tree - most bacteria are of this size. In reality, very few bacteria cause infections by spreading via the airborne route (e.g., mycobacteria, viruses, and legionella). Most bacteria cause pneumonia by first colonizing the upper respiratory tract and later descending into the tracheobronchial tree.

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.

Comprehensive evidence-based clinical practice guidelines for ventilator-associated pneumonia: diagnosis and treatment

BACKGROUND

Ventilator-associated pneumonia (VAP) is an important cause of morbidity and mortality in ventilated critically ill patients. Despite a large amount of research evidence, the optimal diagnostic and treatment strategies for VAP remain controversial.

PURPOSE

The aim of this study was to develop evidence-based clinical practice guidelines for the diagnosis and treatment of VAP. Data sources include Medline, EMBASE, Cumulative Index to Nursing and Allied Health Literature, and the Cochrane Database of Systematic Reviews and Register of Controlled Trials.

STUDY SELECTION

The authors systematically searched for all relevant randomized controlled trials and systematic reviews on the diagnosis and treatment of VAP in mechanically ventilated adults that were published from 1980 to October 1, 2006.

DATA EXTRACTION

Independently and in duplicate, the panel critically appraised each published trial. The effect size, confidence intervals, and homogeneity of the results were scored using predefined definitions. The full guideline development panel arrived at a consensus for scores on safety, feasibility, and economic issues.

LEVELS OF EVIDENCE

Based on the scores for each topic, the following statements of recommendation were used: recommend, consider, do not recommend, and no recommendation because of insufficient or conflicting evidence.

DATA SYNTHESIS

For the diagnosis of VAP in immunocompetent patients, we recommend that endotracheal aspirates with nonquantitative cultures be used as the initial diagnostic strategy. When there is a suspicion of VAP, we recommend empiric antimicrobial therapy (in contrast to delayed or culture directed therapy) and appropriate single agent antimicrobial therapy for each potential pathogen as empiric therapy for VAP. Choice of antibiotics should be based on patient factors and local resistance patterns. We recommend that an antibiotic discontinuation strategy be used in patients who are treated of suspected VAP. For patients who receive adequate initial antibiotic therapy, we recommend 8 days of antibiotic therapy. We do not recommend nebulized endotracheal tobramycin or intratracheal instillation of tobramycin for the treatment of VAP.

CONCLUSION

We present evidence-based recommendations for the diagnosis and treatment of VAP. Implementation of these recommendations into clinical practice may lessen the morbidity and mortality of patients who develop VAP.

Pneumonia caused by methicillin-resistant Staphylococcus aureus

A recent increase in staphylococcal infections caused by methicillin-resistant Staphylococcus aureus (MRSA), combined with frequent, prolonged ventilatory support of an aging, often chronically ill population, has resulted in a large increase in cases of MRSA pneumonia in the health care setting. In addition, community-acquired MRSA pneumonia has become more prevalent. This type of pneumonia historically affects younger patients, follows infection with influenza virus, and is often severe, requiring hospitalization and causing the death of a significant proportion of those affected. Ultimately, hospital-acquired MRSA and community-acquired MRSA are important causes of pneumonia and present diagnostic and therapeutic challenges. Rapid institution of appropriate antibiotic therapy, including linezolid as an alternative to vancomycin, is crucial. Respiratory infection-control measures and de-escalation of initial broad-spectrum antibiotic regimens to avoid emergence of resistant organisms are also important. This article reviews the clinical features of, diagnosis of, and therapies for MRSA pneumonia.

Guidelines for evaluation of new fever in critically ill adult patients: 2008 update from the American College of Critical Care Medicine and the Infectious Diseases Society of America

OBJECTIVE

To update the practice parameters for the evaluation of adult patients who develop a new fever in the intensive care unit, for the purpose of guiding clinical practice.

PARTICIPANTS

A task force of 11 experts in the disciplines related to critical care medicine and infectious diseases was convened from the membership of the Society of Critical Care Medicine and the Infectious Diseases Society of America. Specialties represented included critical care medicine, surgery, internal medicine, infectious diseases, neurology, and laboratory medicine/microbiology.

EVIDENCE

The task force members provided personal experience and determined the published literature (MEDLINE articles, textbooks, etc.) from which consensus was obtained. Published literature was reviewed and classified into one of four categories, according to study design and scientific value.

CONSENSUS PROCESS

The task force met twice in person, several times by teleconference, and held multiple e-mail discussions during a 2-yr period to identify the pertinent literature and arrive at consensus recommendations. Consideration was given to the relationship between the weight of scientific evidence and the strength of the recommendation. Draft documents were composed and debated by the task force until consensus was reached by nominal group process.

CONCLUSIONS

The panel concluded that, because fever can have many infectious and noninfectious etiologies, a new fever in a patient in the intensive care unit should trigger a careful clinical assessment rather than automatic orders for laboratory and radiologic tests. A cost-conscious approach to obtaining cultures and imaging studies should be undertaken if indicated after a clinical evaluation. The goal of such an approach is to determine, in a directed manner, whether infection is present so that additional testing can be avoided and therapeutic decisions can be made.

Short antibiotic treatment courses or how short is short?

Antibiotic therapy in recent years has become more intense and more frequent. Resistance acquisition by community and hospital strains is however also increasing. One of the methods to halt the increase in resistance may be shorter courses of antibiotics, if their clinical efficacy is not impaired. Shorter courses of antibiotic therapy have been very successful in typhoid fever: 3 days; in meningococcal meningitis: a single dose to 3 days' course; ventilator-associated pneumonia: 8 days; and possibly ICU-associated infections: 3-5 days. On the contrary, IV catheter-associated infections require full treatment courses (14 days). More studies are needed in various infectious entities with various agents to be able to better define the optimal duration of therapy.

Diagnostic strategies for nosocomial pneumonia

PURPOSE OF REVIEW

This review describes advances in clinical and microbiological modalities for diagnosis of nosocomial pneumonia and the role of biological markers.

RECENT FINDINGS

Serial assessments with the clinical pulmonary infection score identifies nonsurvivors and allows discontinuation of antibiotics when there is low suspicion of pneumonia. Studies evaluating its clinical utility show mixed results. A meta-analysis revealed that an invasive approach does not affect mortality but reduces costs, antibiotic exposure, and multidrug resistance. In contrast to these findings, a recent trial comparing nonquantitative endotracheal aspirate and quantitative bronchoalveolar lavage cultures showed similar clinical outcomes and antibiotic utilization. The role of quantitative endotracheal aspirate for diagnosis of pneumonia not related to mechanical ventilation was recently evaluated. Procalcitonin and soluble triggering receptor expressed on myeloid cells-1 aid in diagnosis, identify sepsis related to ventilator-associated pneumonia and patients with worst outcomes.

SUMMARY

The diagnostic modality chosen depends on availability, personnel experience, and the patient's clinical status. Recent guidelines support the use of quantitative cultures in an integrated clinical and microbiological algorithm. The decision to adjust antibiotics involves clinical reassessment and interpretation of culture results. Biological markers have a potential role as screening and prognostic tools.

Negative pressure ventilation via diaphragmatic pacing: a potential gateway for treating systemic dysfunctions

Programmed diaphragmatic pacing using implanted neuromodulators represents an emerging method for providing pulmonary support using negative pressure ventilation. The implantable, rechargeable, programmable and miniaturized nature of diaphragmatic pacers may obviate many of the management issues associated with noninvasive positive pressure ventilation devices. Closed loop systems may facilitate the implementation of diaphragmatic pacing for the treatment of many indications. They may allow for wider adoption of ventilatory support in central sleep apnea and improve quality of life in diseases of chronic hypoventilation, such as amyotrophic lateral sclerosis. In addition, it might alleviate subclinical hypoventilation--a condition that may affect a significant proportion of the aging population. Diaphragmatic pacing could also reduce sympathetic bias, which may contribute to a wide range of diseases associated with autonomic dysfunction.

Clinical and hemostatic responses to treatment in ventilator-associated pneumonia: role of bacterial pathogens

OBJECTIVE

To determine pathogen-specific kinetic changes in the alveolar procoagulant (PC) activity, tissue factor (TF), and tissue factor pathway inhibitor (TFPI) expression during the course of ventilator-associated pneumonia (VAP) and to assess the relationship between clinical resolution, intra-alveolar bacterial eradication, and restoration of hemostatic balance.

DESIGN

Prospective, multiple-center study in a cohort of VAP patients.

SETTING

Two university-affiliated intensive care units.

PATIENTS

Thirty-five patients with microbiologically documented VAP who received adequate antimicrobial coverage and 13 controls.

INTERVENTIONS

Nonbronchoscopic bronchoalveolar lavage was performed at the onset of VAP and on days 4 and 8 after initiation of antibiotic therapy. Samples were assayed for PC, TF, TFPI, and thrombin-antithrombin complex (TATc). The corresponding Clinical Pulmonary Infection Score (CPIS) was collected simultaneously.

MEASUREMENTS AND MAIN RESULTS

Isolated pathogens included Pseudomonas aeruginosa (n=13), methicillin-resistant Staphylococcus aureus (MRSA) (n=8), methicillin-sensitive S. aureus (MSSA) (n=7), and Escherichia coli (n=7). Although PC activity and TF were increased among the various pathogens at the onset of VAP, the levels of those with P. aeruginosa remained elevated at the end of treatment compared with controls and other etiological agents. TFPI levels were elevated for the duration of the study for all pathogens. A universal increase in TATc was noted at the onset of VAP, but the difference among the group of pathogens was significant at days 4 and 8 posttherapy. Despite the persisting hemostatic imbalance and incomplete intra-alveolar eradication of P. aeruginosa at end of therapy, the CPIS fell comparably at each time point irrespective of the etiological agents.

CONCLUSIONS

Alveolar activation of the TF-dependent pathway may be species-specific in VAP and may not be adequately balanced by TFPI. The disparity between clinical response and eradication of P. aeruginosa from the intra-alveolar space suggests the need for biological markers to guide response to therapy.

Inadequate treatment of ventilator-associated pneumonia: risk factors and impact on outcomes

Initial antibiotic therapy is an important determinant of clinical outcomes in ventilator-associated pneumonia (VAP). Several studies have investigated this issue, with conflicting results. This study investigated risk factors of inadequate empirical antimicrobial therapy and its impact on outcomes for patients with a clinical diagnosis of VAP. The primary outcome was adequacy of antimicrobial therapy. Secondary outcomes were duration of mechanical ventilation, hospital and intensive care unit (ICU) lengths of stay, and mortality due to VAP. Mean age was 62.9+/-15.2 years, mean APACHE (Acute Physiological Assessment and Chronic Health Evaluation) II score was 20.1+/-8.1 and mean MODS (Multiple Organ Dysfunction Score) was 3.7+/-2.5. Sixty-nine (45.7%) of 151 patients with a clinical diagnosis of VAP received inadequate antimicrobial treatment for VAP initially. There were 100 (66.2%) episodes of VAP caused by multidrug-resistant pathogens, of which 56% were inadequately treated, whereas the rate of inadequate antimicrobial therapy for VAP caused by susceptible-drug pathogens was 25.5% (P<0.001). Multiple logistic regression analysis revealed that the risk of inadequate antimicrobial treatment was more than twice as great for patients with late-onset VAP [odds ratio (OR), 2.93; 95% confidence interval (CI), 1.30-6.64; P=0.01], and more than three times for patients with VAP caused by multidrug-resistant pathogens (OR, 3.07; 95% CI, 1.29-7.30; P=0.01) or with polymicrobial VAP (OR, 3.67; 95% CI, 1.21-11.12; P=0.02). Inadequate antimicrobial treatment was associated with higher mortality for patients with VAP. Two of three independent risk factors for treatment inadequacy were associated with the isolation and identification of micro-organisms.

A randomized trial of diagnostic techniques for ventilator-associated pneumonia

BACKGROUND

Critically ill patients who require mechanical ventilation are at risk for ventilator-associated pneumonia. Current data are conflicting as to the optimal diagnostic approach in patients who have suspected ventilator-associated pneumonia.

METHODS

In a multicenter trial, we randomly assigned immunocompetent adults who were receiving mechanical ventilation and who had suspected ventilator-associated pneumonia after 4 days in the intensive care unit (ICU) to undergo either bronchoalveolar lavage with quantitative culture of the bronchoalveolar-lavage fluid or endotracheal aspiration with nonquantitative culture of the aspirate. Patients known to be colonized or infected with pseudomonas species or methicillin-resistant Staphylococcus aureus were excluded. Empirical antibiotic therapy was initiated in all patients until culture results were available, at which point a protocol of targeted therapy was used for discontinuing or reducing the dose or number of antibiotics, or for resuming antibiotic therapy to treat a preenrollment condition if the culture was negative.

RESULTS

We enrolled 740 patients in 28 ICUs in Canada and the United States. There was no significant difference in the primary outcome (28-day mortality rate) between the bronchoalveolar-lavage group and the endotracheal-aspiration group (18.9% and 18.4%, respectively; P=0.94). The bronchoalveolar-lavage group and the endotracheal-aspiration group also had similar rates of targeted therapy (74.2% and 74.6%, respectively; P=0.90), days alive without antibiotics (10.4+/-7.5 and 10.6+/-7.9, P=0.86), and maximum organ-dysfunction scores (mean [+/-SD], 8.3+/-3.6 and 8.6+/-4.0; P=0.26). The two groups did not differ significantly in the length of stay in the ICU or hospital.

CONCLUSIONS

Two diagnostic strategies for ventilator-associated pneumonia--bronchoalveolar lavage with quantitative culture of the bronchoalveolar-lavage fluid and endotracheal aspiration with nonquantitative culture of the aspirate--are associated with similar clinical outcomes and similar overall use of antibiotics. (Current Controlled Trials number, ISRCTN51767272 [controlled-trials.com].).

Can the clinical pulmonary infection score impact ICU antibiotic days?

BACKGROUND

The Clinical Pulmonary Infection Score (CPIS) has been used in the intensive care unit (ICU) as a decision tool for initiation of antibiotics in suspected pneumonia and also for discontinuing antibiotics if the CPIS score is <or=6 on day three of therapy, but it is not in common clinical use. We sought to determine if application of a CPIS score<or=6 at three days could reduce antibiotic use and if a blinded committee would have a greater percentage of patients with CPIS>6 on day one receiving antibiotics empirically for pneumonia.

METHODS

Over 11 months, we evaluated empiric antibiotics prospectively in two ICUs of a large tertiary university teaching hospital. A pneumonia committee (PC) reviewed all patients and defined pneumonia according to the guidelines of the U.S. Centers for Disease Control and Prevention (CDC). The CPIS was calculated for all patients at day one and day three of antibiotic therapy. The percentage of patients with a CPIS<or=6 was compared for the ICU and PC, and the total antibiotic days potentially saved by using CPIS<or=6 as the criterion for treatment were determined. Receiver operating characteristic (ROC) curves and inter-observer reliability were determined.

RESULTS

Three hundred twelve patients received empiric antibiotics, 83 of whom were believed to have pneumonia by the ICU staff (2,283 antibiotic days). On day one, the 55 patients started on antibiotics had a CPIS<or=6, with 1,460 antibiotic-days, and only 28 patients had a CPIS>6 (823 antibiotic-days). In contrast, the PC determined 19 patients (23%) to have pneumonia by the CDC definition (731 antibiotic-days), with eight of these patients having a CPIS<or=6 and 11 a CPIS>6. Pneumonia committee review resulted in fewer patients believed to have pneumonia and a greater percentage with a CPIS>6 (odds ratio [OR] 2.7; 95% confidence interval [CI] 0.86, 8.6; p=0.05). Restriction of antibiotics to patients with a CPIS>6 would have saved 1,460 antibiotic-days at day one and 1,053 days if treatment was delayed until day three. Clinical Pulmonary Infection Score ROC curves for the PC showed an area under the curve (AUC) of 0.82 (95% CI 0.72, 0.91), whereas the AUC for the ICU group was 0.85 (95% CI 0.79, 0.92). The sensitivity and specificity of a CPIS>6 for the PC were 79% and 75%, respectively, with correct prediction 76% of the time. The inter-observer reliability of the CPIS had a kappa value of 0.88.

CONCLUSIONS

This prospective evaluation confirms that 50% of antibiotic-days in our ICU are used empirically for pneumonia when that infection is not likely to be present by either CDC or CPIS criteria. Although the CPIS has good reliability and acceptable sensitivity and specificity, PC review and CPIS<or=6 were commonly divergent (42-47%). Thus, better strategies should be developed for identification of pneumonia and empiric antibiotic administration in the ICU.

Ventilator-associated pneumonia: diagnosis, treatment, and prevention

While critically ill patients experience a life-threatening illness, they commonly contract ventilator-associated pneumonia. This nosocomial infection increases morbidity and likely mortality as well as the cost of health care. This article reviews the literature with regard to diagnosis, treatment, and prevention. It provides conclusions that can be implemented in practice as well as an algorithm for the bedside clinician and also focuses on the controversies with regard to diagnostic tools and approaches, treatment plans, and prevention strategies.

Diagnosis and Treatment of Ventilator-Associated Pneumonia

Ventilator-associated pneumonia (VAP) is the most common nosocomial infection in the ICU. Patients who acquire VAP have higher mortality rates and longer ICU and hospital stays. Because there are other potential causes of fever, leukocytosis, and pulmonary infiltrates, clinical diagnostic criteria are overly sensitive in the diagnosis of VAP. Employing quantitative cultures of bronchopulmonary secretions in the diagnostic algorithm leads to less antibiotic use and probably to lower mortality. With respect to microbiologic diagnosis, it is not clear that the use of a particular sampling method (bronchoscopic or nonbronchoscopic), when quantitatively cultured, is associated with better outcomes. Delayed administration of adequate antibiotic therapy is linked to an increased mortality rate. Hence, the focus of initial antibiotic therapy should be to rapidly provide antibiotic coverage for all likely pathogens and to then narrow or focus the antibiotic spectrum based on the results of quantitative cultures. Eight days of antibiotic therapy appears equivalent to 15 days of therapy except when treating nonlactose-fermenting Gram-negative organisms. In this latter situation, longer treatment durations appear to reduce the risk of recrudescence after discontinuation of antibiotic therapy. A guideline-based approach using the local hospital or ICU antibiogram can increase the likelihood that adequate initial antibiotic therapy is used and reduce the overall use of antibiotics and the associated selection pressure for multidrug-resistant organisms.

[Management of ventilator acquired pneumonia]

Ventilator-associated pneumonia occurs in the evolution of 8 to 70% of patients in the Intensive Care Unit. It is the main site of nosocomial infection for mechanically ventilated patients. Nosocomial pneumonia represents an important cause of morbidity and mortality, despite progresses in antibiotic prescription, use of intensive care and prevention. This review is based on the ATS guidelines, and reviews epidemiology, diagnosis and treatment of ventilator-acquired pneumonia, in non-immunocompromised adults.

Concordance of antibiotic prophylaxis, direct Gram staining and protected brush specimen culture results for postoperative patients with suspected pneumonia

BACKGROUND AND OBJECTIVES

Antibiotic therapy alters the diagnostic value of protected brush specimens. With protected brush specimens alone, diagnosing pneumonia requires 24 or 48 h. Addition of direct Gram staining shortens this delay. Antibiotic prophylaxis, recommended after major surgery, may influence the contribution of Gram staining to diagnosing postoperative pneumonia.

METHODS

During a 1-yr period, we retrospectively studied all patients on mechanical ventilation suspected of having postoperative pneumonia who had undergone fibreoptic bronchoscopy with protected brush specimens. Postoperative pneumonia was diagnosed when quantitative protected brush specimens culture results yielded 103 colony-forming units mL-1.

RESULTS

Fifty patients were clinically suspected of having postoperative pneumonia after cardiac (n=42), vascular (n=5) or thoracic (n=3) surgery. Eleven (22%) samples were obtained during antibiotic prophylaxis. Twenty-two (44%) episodes were microbiologically proven. Gram-stain sensitivity was 95.5%, with 82.1% specificity, 80.7% positive-predictive value and 95.8% negative-predictive value. Concordance between direct Gram-stain-identified pathogens and Gram stain of cultured pathogens was significantly less frequent during antibiotic prophylaxis (63.6%) than afterwards (94.9%) (P<0.05).

CONCLUSION

Antibiotic prophylaxis diminished the diagnostic value of Gram staining of protected brush specimens. When protected brush specimens was performed during antibiotic prophylaxis, Gram staining accurately enabled early exclusion of postoperative pneumonia because of its excellent negative-predictive value. After antibiotic prophylaxis, Gram staining permitted early diagnosis of postoperative pneumonia identification of the responsible pathogen.

Both early-onset and late-onset ventilator-associated pneumonia are caused mainly by potentially multiresistant bacteria

OBJECTIVE

To compare the causative pathogens of early-onset and late-onset ventilator-associated pneumonia (VAP) diagnosed by bronchoalveolar lavage quantitative cultures. Most previous reports have been based on endotracheal aspirate cultures and gave uncertain findings.

DESIGN

Prospective evaluation of consecutive patients with clinical suspicion for VAP.

SETTING

Multidisciplinary intensive care unit of a university hospital.

PATIENTS AND PARTICIPANTS

During a 3-year period 473 patients with clinical suspicion of VAP entered the study. Diagnosis of VAP was confirmed by cultures of bronchoalveolar lavage (> 10(4) cfu/ml) specimens in 408 patients.

INTERVENTIONS

Protected bronchoalveolar lavage samples were taken. Initial antibiotic therapy was modified upon bronchoalveolar lavage culture results.

MEASUREMENTS AND RESULTS

Among 408 patients 191 had early-onset (< 7 days mechanical ventilation) and 217 late-onset (> or = 7 days) VAP. Potentially multiresistant bacteria, mainly Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus (MRSA), were the most commonly isolated pathogens in both types of VAP. No difference was noted in the contribution of potentially multiresistant pathogens (79% vs. 85%), P. aeruginosa (42% vs. 47%), or MRSA (33% vs. 30%) between early-onset and late-onset VAP. Initial antibiotic therapy was modified in 58% of early-onset VAP episodes and in 36% of late-onset VAP episodes. No difference in mortality was found between the two types of VAP.

CONCLUSIONS

Both early-onset and late-onset VAP were mainly caused by potentially multiresistant bacteria, most commonly P. aeruginosa and MRSA. Antimicrobial agents against these pathogens should be prescribed empirically, at least in our institution.

Community-acquired bacteria frequently detected by means of quantitative polymerase chain reaction in nosocomial early-onset ventilator-associated pneumonia*

OBJECTIVE

To test whether real-time polymerase chain reaction allows for rapid quantitative detection of Streptococcus pneumoniae, Chlamydia pneumoniae, Mycoplasma pneumoniae, and Legionella pneumophila in bronchoalveolar lavage fluids and to determine the prevalence of these pathogens in nosocomial ventilator-associated pneumonia.

DESIGN

Prospective epidemiologic study applying a new molecular biology-based diagnostic tool during a 27-month period.

SETTING

Three medical intensive care units of a tertiary care university hospital.

PATIENTS

One hundred patients suffering from nosocomial ventilator-associated pneumonia, hospitalized for > or =14 days, intubated for reasons other than pneumonia, and mechanically ventilated for >48 hrs.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

S. pneumoniae, M. pneumoniae, and C. pneumoniae were detected in bronchoalveolar lavage fluids of 100 patients in 20 (20%), three (3%), and two (2%) cases, respectively. There of 17 (71%) revealed no growth or no significant growth by conventional culture. In one patient, S. pneumoniae and M. pneumoniae were detected simultaneously. Corresponding colony-forming units/mL were partly up to 10 CFU/mL with Gram stainings showing signs of acute inflammation in 80%. A significant temporary correlation between the number of days on ventilator, development of nosocomial pneumonia, and the frequency of detection of these pathogens was found for day 4.

CONCLUSIONS

S. pneumoniae, M. pneumoniae, and C. pneumoniae should be considered as causative agents in critically ill patients who develop early-onset nosocomial ventilator-associated pneumonia. Thus, empirical antimicrobial regimens should cover S. pneumoniae, Chlamydia, and Mycoplasma alike. Quantitative polymerase chain reaction is a fast diagnostic tool allowing for detection of these bacteria within 3 hrs in pretreated patients.

Bronchoalveolar lavage in diagnosis of ventilator-associated pneumonia in patients with burns

Ventilator-associated pneumonia (VAP) remains a major cause of morbidity and mortality for patients with burns. In nonburn populations, bronchoalveolar lavage (BAL) excludes other pathology such as systemic inflammatory response syndrome. We hypothesized that BAL would decrease our false-positive VAP rate. All ventilated patients with burn injury who were admitted to our institution from July 2000 through June 2003 were included. After June 2001, BAL was used to make the diagnosis of VAP, with > or =10(4) organisms considered a positive result. Fifty patients met criteria for VAP, 21 in the pre-BAL period and 29 in the BAL period. Six patients (21%) in the BAL group had quantitative cultures <10(4) and were not treated. The outcomes for these patients were not different than those treated for VAP. There were no differences in age, TBSA size, antibiotic use, or ventilator days for the pre-BAL or BAL groups, although the pneumonia rate was lower for the BAL time period. The use of BAL eliminated the unnecessary antibiotic treatment of 21% of patients in the BAL time period and was associated with a lower rate of VAP.

Diagnosis of infection in sepsis: An evidence-based review

OBJECTIVE

In 2003, critical care and infectious disease experts representing 11 international organizations developed management guidelines for the diagnosis of infection in sepsis that would be of practical use for the bedside clinician, under the auspices of the Surviving Sepsis Campaign, an international effort to increase awareness and improve outcome in severe sepsis.

DESIGN

The process included a modified Delphi method, a consensus conference, several subsequent smaller meetings of subgroups and key individuals, teleconferences, and electronic-based discussion among subgroups and among the entire committee.

METHODS

The modified Delphi methodology used for grading recommendations built on a 2001 publication sponsored by the International Sepsis Forum. We undertook a systematic review of the literature graded along five levels to create recommendation grades from A to E, with A being the highest grade. Pediatric considerations to contrast adult and pediatric management are in the article by Parker et al. on p. S591.

CONCLUSIONS

Obtaining a precise bacteriological diagnosis before starting antibiotic therapy is, when possible, of paramount importance for the success of therapeutic strategy during sepsis. Two to three blood cultures should be performed, preferably from a peripheral vein, without interval between samples to avoid delaying therapy. A quantitative approach is preferred in most cases when possible, in particular for catheter-related infections and ventilator-associated pneumonia. Diagnosing community-acquired pneumonia is complex, and a diagnostic algorithm is proposed. Appropriate samples are indicated during soft tissue and intraabdominal infections, but cultures obtained through the drains are discouraged.