Attributable mortality of ventilator-associated pneumonia: a meta-analysis of individual patient data from randomised prevention studies

Guidelines vs mindlines: a qualitative investigation of how clinicians' beliefs influence the application of rapid molecular diagnostics in intensive care

Rapid molecular diagnostic tests improve antimicrobial stewardship (AMS) by facilitating earlier refinement of antimicrobial therapy. The INHALE trial tested the application of the BioFire FilmArray Pneumonia Panel (Pneumonia Panel) for antibiotic prescribing for hospital-acquired and ventilator-associated pneumonias (HAP/VAP) in UK intensive care units (ICUs). We report a behavioral study embedded within the INHALE trial examining clinicians' perceptions of using these tests. Semi-structured interviews were conducted with 20 ICU clinicians after using the Pneumonia Panel to manage suspected HAP/VAP. Thematic analysis identified factors reinforcing perceptions of the necessity to modify antibiotic prescribing in accordance with test results and doubts/concerns about doing so. While most acknowledged the importance of AMS, the test's impact on prescribing decisions was limited. Concerns about potential consequences of undertreatment to the patient and prescriber were often more salient than AMS, sometimes leading to "just-in-case" antibiotic prescriptions. Test results indicating a broad-spectrum antibiotic were unnecessary often failed to influence clinicians to avoid an initial prescription or de-escalate antibiotics early as they considered their use to be necessary to protect the patient and themselves, "erring on the side of caution." Some clinicians described cases where antibiotics would be prescribed for a sick patient regardless of test results because, in their opinion, it fits with the clinical picture-"treating the patient, not the result." Our findings illustrate a tension between prescribing guidelines and clinicians' "mindlines," characterized by previous experiences. This highlights the need for a "technology plus" approach, recognizing the challenges clinicians face when applying technological solutions to patient care.IMPORTANCERapid molecular diagnostic tests for pathogens and resistance genes may improve antibiotic-prescribing decisions and stewardship. However, clinicians' desire to protect their patients with antibiotics often overrides more distal concerns about possible resistance selection, limiting the application of these tests in practice. Findings underscore the challenge of changing prescribing decisions based on technical results or guidelines, highlighting factors such as clinicians' previous experience and "knowledge in practice" as more proximal drivers of these decisions. Implementation strategies for technological solutions to antimicrobial resistance must be "behaviorally intelligent," recognizing the challenges facing clinicians when making "life or death" prescribing decisions.CLINICAL TRIALSThis study is registered with ISRCTN as ISRCTN16483855.

Stepwise implementation of prevention strategies and their impact on ventilator-associated pneumonia incidence: A 13-Year observational surveillance study

OBJECTIVE

To describe the practice of ventilator-associated pneumonia (VAP) prevention and control through the incremental introduction of prevention strategies and assess the effect on VAP incidence.

DESIGN

Historical observational surveillance study conducted over 13 years.

SETTING

A 12-bed adult intensive care unit (ICU) in a general hospital in Belgium.

PARTICIPANTS

Patients admitted between 2007 and 2019, with ICU stays of ≥48 h.

INTERVENTIONS

Incremental introduction of VAP preventive measures from 2008, including head-of-bed elevation, cuff pressure control, endotracheal tubes with tapered cuffs, subglottic secretion drainage, chlorhexidine oral care, and daily sedation assessment.

MEASUREMENTS AND MAIN RESULTS

A significant decline in VAP incidence density rates was observed, from 18.3 to 2.6 cases per 1000 ventilator days from the baseline to the final period.

CONCLUSIONS

Systematic implementation of VAP preventive measures significantly reduced VAP incidence. However, this reduction did not translate into decreased overall ICU mortality.

IMPLICATIONS FOR PRACTICE

The study underscores the importance of continuous VAP surveillance and preventive measures in reducing VAP incidence.

Clinical impact of healthcare-associated infections in Brazilian ICUs: a multicenter prospective cohort

BACKGROUND

Limited data is available to evaluate the burden of device associated healthcare infections (HAI) [central line associated bloodstream infection (CLABSI), catheter associated urinary tract infection (CAUTI), and ventilator associated pneumonia (VAP)] in low and-middle-income countries. Our aim is to investigate the population attributable mortality fraction and the absolute mortality difference of HAI in a broad population of critically ill patients from Brazil.

METHODS

Multicenter cohort study from September 2019 to December 2023 with prospective individual patient data collection. VAP, CLABSI, and CAUTI were diagnosed by each center in accordance with Brazilian regulatory agency guidance. If a patient fulfilled all diagnostic criteria, he was deemed to have Confirmed HAI. An adjusted disability multistate model was used to evaluate the population attributable in-hospital mortality fraction (PAF) and the absolute in-hospital mortality difference (AMD).

RESULTS

A total of 128,247 patients were included. 4066 (3.2%) distinct patients had at least one diagnosis of HAI (1493 CLABSI, 433 CAUTI, 2742 VAP, and 435 patients with more than one HAI) during the ICU stay. The PAF was 3.89% (95% CI 3.68-4.11%) for HAI, 2.16% (2.05-2.33%) for VAP, 1.2% (1.08-1.32%) for CLABSI, 0.11% (0.07-0.16%) for CAUTI, and 0.33% (0.26-0.4%) for ≥ 2 HAI. The AMD for HAI was 33.69% (95% CI 32.27-35.33%), 29.01% (27.15-30.98%) for VAP, 31.64% (29.3-34.81%) for CLABSI, 9.94% (3.88-15.54%) for CAUTI and 35.6% (28.93-42.99%) for ≥ 2 HAI.

CONCLUSIONS

Device-associated HAI significantly contribute to hospital mortality and impose a high excess risk of death for critically ill patients.

Hybrid Cell Membrane-Engineered Nanocarrier for Triple-Action Strategy to Address Pseudomonas aeruginosa Infection

Bacterial infections resistant to antimicrobial treatments, particularly those caused by Pseudomonas aeruginosa (P. aeruginosa), frequently lead to elevated mortality rates. Tackling this resistance using therapeutic combinations with varied mechanisms has shown considerable promise. In this study, a bioinspired nanocarrier is successfully designed and engineered for targeted antibiotic delivery and toxin/bacteria clearance. This is achieved by encapsulating antibiotic-loaded framework nucleic acids with hybrid cell membranes acquired from neutrophils and platelets. By coating the hybrid membrane outside the shell, nanocarriers are endowed with the function of neutrophil-like chemotaxis and platelet-like bacteria adhesion to achieve the first stage of inflammation targeting. Based on the specific binding of bacteria toxin to the hybrid membrane, the release of antibiotic-loaded framework nucleic acids is triggered by toxin-mediated membrane lysis to fulfill the second stage of toxin neutralization and bacteria killing. Meanwhile, the immunomodulation potential of framework nucleic acids enables nanocarriers to accomplish the third stage of reversing the immunosuppressive microenvironment. In mouse models of acute and chronic P. aeruginosa pneumonia, the nanocarriers can reduce bacterial burden at a low dosage and decrease mortality with negligible toxicity. In sum, these findings have illustrated the remarkable capability of nanocarriers in treating recalcitrant bacterial infections.

Comparative efficacy of various oral hygiene care methods in preventing ventilator-associated pneumonia in critically ill patients: A systematic review and network meta-analysis

Oral hygiene care is important for ventilator-associated pneumonia prevention. However, the optimal oral hygiene care approach remains unclear. A network meta-analysis was conducted to compare the efficacy of various oral hygiene care methods for ventilator-associated pneumonia prevention in critically ill patients, and the methods were ranked. A literature search of three representative databases was conducted. We only analyzed parallel randomized controlled trials conducted to analyze the use antiseptics or toothbrushes in oral hygiene care for adult patients undergoing invasive mechanical ventilation in the intensive care unit. The outcome measure was the incidence of ventilator-associated pneumonia. Bias risk was assessed using the Cochrane Risk of Bias 2 tool, and the confidence in the evidence was evaluated using the CINeMA approach. Statistical analyses were performed using R 4.2.0., GeMTC package, and JAGS 4.3.1. The review protocol was registered in PROSPERO (registration number: CRD42022333270). Thirteen randomized controlled trials were included in the qualitative synthesis and twelve randomized controlled trials (2395 participants) were included in the network meta-analysis. Over 50% of the included studies were conducted in medical-surgical intensive care units. Ten treatments were analyzed and 12 pairwise comparisons were conducted in the 12 included studies. Analysis using surface under the cumulative ranking curves revealed that brushing combined with chlorhexidine 0.12% was most likely the optimal intervention for preventing ventilator-associated pneumonia (88.4%), followed by the use of chlorhexidine 0.12% alone (76.1%), and brushing alone (73.2%). Oral hygiene care methods that included brushing had high rankings. In conclusion, brushing combined with chlorhexidine 0.12% may be an effective intervention for preventing ventilator-associated pneumonia in critically ill patients. Furthermore, brushing may be the optimal oral hygiene care method for preventing ventilator-associated pneumonia in the intensive care unit. Further research is needed to verify these findings as the CINeMA confidence rate was low for each comparison.

Comparison of targeted next-generation sequencing and traditional microbial culture in the diagnosis of pulmonary infections

This study investigated the diagnostic potential of targeted next-generation sequencing (tNGS) for pulmonary infections. The positivity rate of tNGS was significantly higher than that of traditional microbial culture (92.6 % vs 25.2 %, χ2 = 378.272, P < 0.001). The proportion of two or more species of pathogens detected using tNGS exceeded that detected using microbial culture (χ2 = 337.283, P < 0.001). There were inconsistencies between the results of the tNGS antibiotic resistance gene and the drug susceptibility test resistance phenotype. The tNGS technique demonstrates rapid and effective capabilities in identifying bacteria, fungi, viruses, and specific pathogens, with a detection sensitivity that surpasses that of conventional culture methodologies. Microbial drug resistance genotypes detected by tNGS cannot accurately predict drug resistance phenotypes and require further improvement or integration with traditional microbial culture to establish a foundation for effective clinical treatment.

Value of bronchial amylase level for predicting ventilator associated pneumonia in intubated adults: a systematic review and meta-analysis

BACKGROUND

The ability of bronchial amylase level for predicting ventilator associated pneumonia (VAP) has been extensively studied with conflicting results. This meta-analysis aimed to explore the value of bronchial amylase for predicting VAP in intubated adults.

METHODS

PubMed, Embase, and Cochrane Central Register of Controlled Trials were searched up to November 2023. The diagnostic odds ratio (DOR), sensitivity, and specificity were calculated. The summary receiver operating characteristic curve was estimated, and the area under the curve (AUROC) was calculated.

RESULTS

Overall, six studies including 769 patients were included in this review, of whom 273 (36%) were developed VAP. The cutoff values of bronchial amylase level were ranged from 8.1 U/L to 4681.5U/L. Heterogeneity between studies was assessed with an overall Q = 1.99, I2 = 0, and P = 0.185, The pooled sensitivity and specificity for the overall population were 0.78 [95% confidence interval (CI) 0.67-0.86] and 0.75(95% CI 0.56-0.88) respectively. The DOR was 11(95% CI 3.0-40.0). The pooled AUROC was 0.83 (95%CI 0.80-0.86).

CONCLUSIONS

The bronchial amylase is a helpful marker for predicting VAP in intubated adults. However, it cannot be recommended as the single definitive test for VAP, but rather it must be interpreted in context with information from careful medical history, physical examination, and when feasible, microbiological assessment.

A Glycopolymer Sensor Array That Differentiates Lectins and Bacteria

Identification of bacterial lectins offers an attractive route to the development of new diagnostics, but the design of specific sensors is complicated by the low selectivity of carbohydrate-lectin interactions. Here we describe a glycopolymer-based sensor array which can identify a selection of lectins with similar carbohydrate recognition preferences through a pattern-based approach. Receptors were generated using a polymer scaffold functionalized with an environmentally sensitive fluorophore, along with simple carbohydrate motifs. Exposure to lectins induced changes in the emission profiles of the receptors, enabling the discrimination of analytes using linear discriminant analysis. The resultant algorithm was used for lectin identification across a range of concentrations and within complex mixtures of proteins. The sensor array was shown to discriminate different strains of pathogenic bacteria, demonstrating its potential application as a rapid diagnostic tool to characterize bacterial infections and identify bacterial virulence factors such as production of adhesins and antibiotic resistance.

Gas chromatography-ion mobility spectrometry for the detection of human disease: a review

Gas chromatography-ion mobility spectrometry (GC-IMS) is an advanced technique used for detecting trace compounds, due to its non-destructive, straightforward, and rapid analytical capabilities. However, the application of GC-IMS in human disease screening is barely reported. This review summarizes the application and related parameters of GC-IMS in human disease diagnosis. GC-IMS detects volatile organic compounds in human breath, feces, urine, bile, etc. It can be applied to diagnose diseases, such as respiratory diseases, cancer, enteropathy, Alzheimer's disease, bacterial infection, and metabolic diseases. Several potential disease markers have been identified by GC-IMS, including ethanal (COVID-19), 2-heptanone (lung cancer) and 3-pentanone (pulmonary cryptococcosis). In conclusion, GC-IMS offers a non-invasive approach to monitor and diagnose human diseases with broad applications.

Enhancing ICU Outcomes Through Intelligent Monitoring Systems: A Comparative Study on Ventilator-Associated Events

Background: Using intelligent monitoring systems can potentially improve the identification and management of ventilator-associated events (VAEs). This single-center retrospective observational study evaluated the impact of implementing intelligent monitoring systems on the clinical outcomes of patients with VAEs in an ICU setting. Method: An intelligent VAE monitoring system was integrated into electronic medical records to continuously collect patient data and alert attending physicians when a ventilated patient met the criteria for a ventilator-associated condition, which was defined as an increase of at least three cm H2O in positive end expiratory pressure (PEEP), an increase of at least 0.20 in the fraction of inspired oxygen (FiO2), or the FiO2 being over baseline for at least two consecutive days. This study covered two phases, consisting of before using the intelligent monitoring system (2021-2022) and during its use (2023-2024). Results: The results showed that patients monitored with the intelligent system experienced earlier VAE detection (4.96 ± 1.86 vs. 7.77 ± 3.35 days, p < 0.001), fewer ventilator-associated condition (VAC) occurrences, and a shorter total duration of VACs. Additionally, the system significantly reduced ventilator days, antibiotic use, and 14-day mortality. Conclusions: Intelligent monitoring systems enhance VAE management, improve clinical outcomes, and provide valuable insights into the future of critical care medicine.

Lung Ultrasound Score as a Predictor of Clinical Severity and Prognosis in Patients of Ventilator-associated Pneumonia

Background

To estimate a correlation between change in lung ultrasound aeration score (LUSS) and mortality in patients with ventilator-associated pneumonia.

Materials and methods

We conducted a prospective observational study in which lung ultrasound, the partial pressure of arterial oxygen to fraction of inspired oxygen ratio (PaO2/FiO2 ratio), and static lung compliance were performed for five consecutive days since the diagnosis of ventilator-associated pneumonia (day 1-5) in a 20-bed multidisciplinary intensive care unit in at a tertiary care academic institute in Northern India. A hundred and seventeen ventilated patients were studied for the first 5 days after ventilator-associated pneumonia (VAP) development. Lung ultrasounds were performed with an ultrasonography machine using a round-tipped probe of 2-5 MHz at six different areas of each hemithorax, which includes superior and inferior in anterior, lateral, and posterior lung fields. Patients with a decreased LUSS of 2 were labeled as responders. A decrease of LUSS of less than 2 or an increase of LUSS were leveled as nonresponders.

Results

The correlation between the change in LUSS between days 1 and 5 was significant with 28-day mortality (26.3% in responders vs 87.8% nonresponses with p < 0.001).

Conclusion

The responders to treatment for VAP described by LUSS had lower mortality than non-responders.

How to cite this article

Panda S, Agarwal A, Mishra SB, Jain G, Talawar P. Lung Ultrasound Score as a Predictor of Clinical Severity and Prognosis in Patients of Ventilator-associated Pneumonia. Indian J Crit Care Med 2024;28(11):1009-1014.

Microbial dynamics, risk factors and outcomes of secondary pneumonia in critically ill patients with COVID-19: A multicenter retrospective cohort study

BACKGROUND

Secondary pneumonia has a significant clinical impact on critically ill patients with COVID-19.

AIM

Considering potential geographic variations, this study explores the clinical implications of secondary pneumonia within East Asian populations.

METHODS

This multicenter, retrospective cohort study enrolled critical COVID-19 patients requiring intensive care units (ICUs) admission in Taiwan from December 31, 2020, to June 1, 2022.

FINDINGS

Among the 187 critical COVID-19 patients, 80 (42.8%) developed secondary pneumonia. The primary causative pathogens were gram-negative bacilli (GNB) (76.8%). Gram-positive cocci and fungi were mainly observed during the initial two weeks of ICU stay. Notably, the incidence of pulmonary aspergillosis was 9.2% during the first week of ICU stay and all Staphylococcus aureus were susceptible to methicillin. Multi-drug resistant organisms (MDROs) were responsible for 28.3% of the cases, exhibiting significantly longer ICU stays compared to the non-MDRO group (median, 27 vs. 14 days, P < 0.001). In the multivariate analysis, Acute Physiology and Chronic Health Evaluation II (APACHE II) and Sequential Organ Failure Assessment (SOFA) scores were associated with a significantly increased risk of secondary pneumonia. In-hospital mortality was significantly higher in patients with secondary pneumonia than in those without (37.7% vs. 16.7%, P = 0.02) and survival analysis demonstrated gram-negative bacilli-related secondary pneumonia contributed to a worse prognosis.

CONCLUSION

Secondary pneumonia in critical COVID-19 patients significantly raised in-hospital mortality and extended hospital and ICU stays. Moreover, the presence of GNB notably predicted an unfavorable prognosis.

A Comparison of Different Strategies for Optimizing the Selection of Empiric Antibiotic Therapy for Pneumonia Caused by Gram-Negative Bacteria in Intensive Care Units: Unit-Specific Combination Antibiograms Versus Patient-Specific Risk Factors

Background

Guidelines suggest dual antipseudomonal therapy for empiric treatment of pneumonia caused by gram-negative bacteria in intensive care unit (ICU) patients. Additionally, consideration of local susceptibility data and patient-specific risk factors for resistance is recommended for selecting optimal empiric regimens. However, data assessing how to best do this are lacking, and it is unclear whether a local susceptibility data-based or a patient-specific risk factor-based approach will better drive appropriate empiric treatment. This study aims to compare these 2 strategies.

Methods

This retrospective study was divided into 2 periods. In period I, gram-negative respiratory cultures from ICU patients were used to develop unit-specific combination antibiograms, and individual patient charts were reviewed to assess the impact of risk factors on antimicrobial susceptibility to develop a risk factor-based treatment algorithm. Optimal empiric regimens based on these 2 strategies were then defined. In period II, these regimens were hypothetically applied to patients to compare rates of appropriate empiric therapy and overuse by the 2 methods.

Results

Risk factor-based regimens had a higher appropriateness rate compared to regimens derived from antibiograms (89.9% vs 83.7%). Additionally, applying antibiogram-based regimens resulted in a higher prevalence of antibiotic overuse than a patient-specific risk factor-based approach (69.8% vs 40.3%), with excess overuse driven by a higher frequency of unnecessary use of combination therapy.

Conclusions

Both strategies provided high rates of appropriateness in empiric antibiotic selection. However, the patient-specific risk factor-based approach demonstrated a higher rate of appropriate therapy and offered advantages in reducing rates of unnecessary combination therapy.

Selective Digestive Decontamination: A Comprehensive Approach to Reducing Nosocomial Infections and Antimicrobial Resistance in the ICU

Background/Objective: Multidrug-resistant (MDR) bacteria pose a significant threat to global health, especially in intensive care units (ICUs), where high antibiotic consumption drives antimicrobial resistance. Selective digestive decontamination (SDD) is a strategy designed to prevent nosocomial infections and colonization by MDR pathogens. This study aimed to evaluate the impact of implementing an SDD protocol on antibiotic consumption and colonization by carbapenemase-producing Enterobacterale (CPE) in a specific ICU setting. Methods: This quasi-experimental study was conducted in the ICU of a university hospital from June 2021 to June 2023. Patients were divided into two groups: pre-intervention (before SDD) and post-intervention (after SDD implementation). Data on antibiotic consumption (expressed as defined daily doses (DDDs) per 100 stays), nosocomial infections, colonization rates, and the incidence of MDR bacteria were collected. A statistical analysis was conducted to compare the pre- and post-intervention groups. Results: A total of 3266 patients were included, with 1532 in the pre-intervention group and 1734 in the post-intervention group. The implementation of the SDD protocol resulted in a significant reduction in total antibiotic consumption (p = 0.028), with notable decreases in carbapenem use (p < 0.01) and colonization by CPE (p = 0.0099). The incidence of nosocomial infections also decreased in the post-SDD group, although this reduction was not statistically significant. Conclusions: The implementation of the SDD protocol in this ICU setting significantly reduced antibiotic consumption and colonization by CPE. These findings suggest that SDD may be a valuable tool in managing antimicrobial resistance in critical care settings, without contributing to the development of MDR bacteria.

Prophylactic Antibiotics in Adults With Acute Brain Injury Who Are Invasively Ventilated in the ICU: A Systematic Review and Meta-Analysis

BACKGROUND

Lower respiratory tract infections are common in patients receiving invasive mechanical ventilation in an ICU after an acute brain injury and may have deleterious consequences.

RESEARCH QUESTION

In adults with acute brain injury receiving invasive mechanical ventilation in an ICU, is the administration of prophylactic parenteral antibiotics, compared with placebo or usual care, associated with reduced mortality?

STUDY DESIGN AND METHODS

We conducted a systematic review and meta-analysis. We searched for randomized clinical trials (RCTs) in electronic databases, as well as unpublished trials. The primary outcome was hospital mortality, and secondary outcomes included the incidence of ventilator-associated pneumonia, ICU length of stay, and duration of mechanical ventilation. We used a random effects model to estimate the pooled risk ratio (RR) with corresponding 95% CI for binary outcomes and the mean difference (MD) with 95% CI for continuous outcomes. Certainty of evidence was evaluated using Grading of Recommendations Assessment Development and Evaluation methods.

RESULTS

One thousand seven hundred twenty-eight reports of studies were screened, with 7 RCTs recruiting 835 participants included. No trials were adjudicated as having a high risk of bias. The pooled estimated RR for mortality associated with the use of prophylactic antibiotics was 0.91 (95% CI, 0.70-1.17; P = .39; low certainty). The pooled estimated RR for ventilator-associated pneumonia was 0.56 (95% CI, 0.35-0.89; low certainty). The pooled estimated duration of mechanical ventilation for those allocated to prophylactic antibiotics compared with control participants (MD, -2.0 days; 95% CI, -6.1 to 2.1 days; very low certainty) and duration of ICU admission (MD, -2.2 days; 95% CI, -5.4 to 1.1 days; very low certainty) were similar.

INTERPRETATION

Current evidence from randomized clinical trials does not provide definitive evidence regarding the effect of prophylactic antibiotics on mortality in patients receiving invasive mechanical ventilation in the ICU.

CLINICAL TRIAL REGISTRY

International Prospective Register of Systematic Reviews; No.: CRD42023424732; URL: https://www.crd.york.ac.uk/prospero/.

Rapid quantification of polymyxin B in human pulmonary epithelial lining fluid by LC-MS/MS and its clinical application

Pulmonary epithelial lining fluid (ELF) was commonly used for the pharmacokinetic study in lower respiratory tract infections. To characterize the intrapulmonary pharmacokinetic properties of polymyxin B following aerosol delivery, we developed and fully validated a liquid chromatography/tandem mass spectrometry (LC/MS/MS) method for quantifying polymyxin B in human bronchoalveolar lavage fluid (BALF). The ELF concentrations were calculated by the BALF values of polymyxin B using urea as a volume normalizer. Chromatographic separation was achieved on a Phonomenex Kinetex XB-C18 column(100 mm × 2.1 mm I.D., 2.6 μm)in acetonitrile and water both containing 0.2 % formic acid. The flow rate was set as 0.4 mL/min for a 3.5 min running time. Protein precipitation was used in preparing BALF samples with polymyxin E1 as an internal standard. Polymyxin B was detected under multiple reaction monitoring conditions using the electrospray ionization interface running in the positive ionization mode. The assay showed a good linear relationship over the tested concentration ranges of 0.0300/0.00306---10.0/1.02 mg/L for polymyxin B1/B2 in bronchoalveolar lavage fluid (R2 > 0.99). The inter- and inter-day precisions (RSD, %) were < 12.2 %(15.2 % for LLOQ samples)and the accuracies (%) were within the range of 94.3 ∼ 110.4 %. This reliable LC-MS/MS method for detection of polymyxin B was successfully applied to conduct a pulmonary penetration study in patients following aerosol administration.

Prophylactic Antibiotics Delivered Via the Respiratory Tract to Reduce Ventilator-Associated Pneumonia: A Systematic Review, Network Meta-Analysis, and Trial Sequential Analysis of Randomized Controlled Trials

OBJECTIVES

To assess the effects of antibiotics delivered via the respiratory tract in preventing ventilator-associated pneumonia (VAP).

DATA SOURCES

We searched PubMed, Scopus, the Cochrane Library, and ClinicalTrials.gov for studies published in English up to October 25, 2023.

STUDY SELECTION

Adult patients with mechanical ventilation of over 48 h and receiving inhaled or instilled antibiotics (with control group) to prevent VAP were included.

DATA EXTRACTION

Two independent groups screened studies, extracted the data, and assessed the risk of bias. The Grading of Recommendations Assessment, Development, and Evaluation approach was used to assess the certainty/quality of the evidence. Results of a random-effects model were reported for overall and predefined subgroup meta-analyses. The analysis was primarily conducted on randomized controlled trials, and observational studies were used for sensitivity analyses.

DATA SYNTHESIS

Seven RCTs with 1445 patients were included, of which six involving 1283 patients used nebulizers to deliver antibiotics. No obvious risk of bias was found among the included RCTs for the primary outcome. Compared with control group, prophylactic antibiotics delivery via the respiratory tract significantly reduced the risk of VAP (risk ratio [RR], 0.69 [95% CI, 0.53-0.89]), particularly in subgroups where aminoglycosides (RR, 0.67 [0.47-0.97]) or nebulization (RR, 0.64 [0.49-0.83]) were used as opposed to other antibiotics (ceftazidime and colistin) or intratracheal instillation. No significant differences were observed in mortality, mechanical ventilation duration, ICU and hospital length of stay, duration of systemic antibiotics, need for tracheostomy, and adverse events between the two groups. Results were confirmed in sensitivity analyses.

CONCLUSIONS

In adult patients with mechanical ventilation for over 48 h, prophylactic antibiotics delivered via the respiratory tract reduced the risk of VAP, particularly for those treated with nebulized aminoglycosides.

Mortality rate analysis of patients on invasive mechanical ventilation in the intensive care unit on day 28

Outcomes in patients receiving invasive mechanical ventilation (IMV) are currently unclear. The present study aimed to explore the prognostic factors of the mortality rate on day 28 in patients treated in the intensive care unit (ICU) and undergoing IMV. The IMV Mortality Prediction Score (IMPRES) of 129 patients in the ICU receiving IMV after emergency (or selective) endotracheal intubation from March 2018 to August 2020 was calculated. The patients were divided into survival (n=73) and death groups (n=56) on day 28. The predictive factors of independent and combined mortality rates were determined using a receiver operating characteristic (ROC) curve and the area under the ROC curve (AUC). The AUC of the IMPRES for predicting patient death on day 28 was 0.785 (95% confidence interval (CI): 0.704-0.864, P<0.01). When the IMPRES cut-off was 4.50, the Youden index was at its maximum (0.487) with a sensitivity of 85.7% and a specificity of 63.0%. The AUC of the ventilator use time (days) at 12.5 days cut-off was 0.653 (95% CI: 0.56-0.746, P<0.01), the Youden index was 0.235 with a sensitivity of 52.1% and a specificity of 71.4%. The AUC of the IMPRES combined with the duration of ventilator use was 0.856 (95% CI: 0.789-0.922, P<0.001), the Youden index was 0.635 with a sensitivity of 84.9% and a specificity of 78.6%. The IMPRES was observed to be the main factor influencing the mortality rate of patients receiving IMV at the ICU on day 28, and the IMPRES combined with the duration of ventilator use had a significant predictive value for the 28-day mortality rates of these patients.

Incidence and predictors of ventilator-associated pneumonia using a competing risk analysis: a single-center prospective cohort study in Egypt

BACKGROUND

Ventilator-associated pneumonia (VAP) is a challenging nosocomial problem in low- and middle-income countries (LMICs) that face barriers to healthcare delivery and resource availability. This study aimed to examine the incidence and predictors of VAP in Egypt as an example of an LMIC while considering death as a competing event.

METHODS

The study included patients aged ≥ 18 years who underwent mechanical ventilation (MV) in an intensive care unit (ICU) at a tertiary care, university hospital in Egypt between May 2020 and January 2023. We excluded patients who died or were transferred from the ICU within 48 h of admission. We determined the VAP incidence based on clinical suspicion, radiological findings, and positive lower respiratory tract microbiological cultures. The multivariate Fine-Gray subdistribution hazard model was used to examine the predictors of VAP while considering death as a competing event.

RESULTS

Overall, 315 patients were included in this analysis. Sixty-two patients (19.7%) developed VAP (17.1 per 1000 ventilator days). The Fine-Gray subdistribution hazard model, after adjustment for potential confounders, revealed that emergency surgery (subdistribution hazard ratio [SHR]: 2.11, 95% confidence interval [CI]: 1.25-3.56), reintubation (SHR: 3.74, 95% CI: 2.23-6.28), blood transfusion (SHR: 2.23, 95% CI: 1.32-3.75), and increased duration of MV (SHR: 1.04, 95% CI: 1.03-1.06) were independent risk factors for VAP development. However, the new use of corticosteroids was not associated with VAP development (SHR: 0.94, 95% CI: 0.56-1.57). Klebsiella pneumoniae was the most common causative microorganism, followed by Pseudomonas aeruginosa.

CONCLUSION

The incidence of VAP in Egypt was high, even in the ICU at a university hospital. Emergency surgery, reintubation, blood transfusion, and increased duration of MV were independently associated with VAP. Robust antimicrobial stewardship and infection control strategies are urgently needed in Egypt.

Aerosolized Antibiotic Therapy in Mechanically Ventilated Patients

Delivering antibiotics directly to the respiratory tract through inhalation to address lung infections has garnered clinical and scientific interest for decades, given the potential favorable pharmacokinetic profile of this administration route. Among critically ill patients, the burden of healthcare-associated pulmonary infections particularly drove continued interest in delivering inhaled antibiotics to intubated patients. We present a concise overview of the existing rationale and evidence and provide guidance for implementing inhaled antibiotics among ventilated critically ill patients, emphasizing insights from recent literature.

Survival analysis of COVID-19 versus non-COVID-19 patients requiring intensive care for acute respiratory distress syndrome: An observational retrospective study

Background/Aim

This study analyzed clinical factors impacting the survival of COVID-19 patients with acute respiratory distress síndrome, or ARDS (CARDS) to ICU compared to non-COVID-19 ARDS patients.

Methods

Clinical variables from 1,008 CARDS cases and 332 ARDS cases were computed using learning algorithms. The multivariable Cox proportional hazards regression models with the enter method evaluated risk factors and ICU mortality relationships. The survival analysis was completed with Kaplan-Meier and the log-rank tests.

Results

A Random Forest model revealed that mechanical ventilation-related factors, oxygenation, blood pH, superinfection, shock, and ICU length of stay have the greatest effects on ICU survival. According to a multivariate Cox model, reintubation and a high-flow nasal cannula were essential for survival in CARDS patients during the ICU stay. The length of stay in the ICU diminishes in patients older than 45 years, regardless of the source of ARDS.

Conclusion

This study gives recommendations for the respiratory care of ARDS in COVID-19 patients.

Guidelines for Antibiotics Prescription in Critically Ill Patients

How to cite this article: Khilnani GC, Tiwari P, Mittal S, Kulkarni AP, Chaudhry D, Zirpe KG, et al. Guidelines for Antibiotics Prescription in Critically Ill Patients. Indian J Crit Care Med 2024;28(S2):S104-S216.

Ventilator-associated pneumonia: pathobiological heterogeneity and diagnostic challenges

Ventilator-associated pneumonia (VAP) affects up to 20% of critically ill patients and induces significant antibiotic prescription pressure, accounting for half of all antibiotic use in the ICU. VAP significantly increases hospital length of stay and healthcare costs yet is also associated with long-term morbidity and mortality. The diagnosis of VAP continues to present challenges and pitfalls for the currently available clinical, radiological and microbiological diagnostic armamentarium. Biomarkers and artificial intelligence offer an innovative potential direction for ongoing future research. In this Review, we summarise the pathobiological heterogeneity and diagnostic challenges associated with VAP.

Bed occupancy and nosocomial infections in the intensive care unit: A retrospective observational study in a tertiary hospital

Background

Healthcare-associated infections (HAI) are a major problem globally, contributing to prolonged hospital admissions and poor outcomes.

Objectives

To examine HAI incidence and risk factors in an intensive care unit (ICU) during high v. low occupancy periods.

Methods

This retrospective, descriptive analysis investigated HAI incidence among adult patients admitted to the ICU at Chris Hani Baragwanath (CHBH) during a high (H2019) and low (L2020) occupancy. Data were extracted from the clinical records of 440 eligible patients.

Results

We found an increased risk of HAI during H2019 compared with L2020 (relative risk (RR) 1.42, 95% confidence interval (CI) 1.03 - 1.94). The overall frequency density of HAI was 25/1 000 ICU days. There was no difference in the distribution of the site of infection (blood v. other) (p=0.27) or bacterial category (Gram stain) (p=0.62). Five organisms accounted for 89% of pathogens: Klebsiella (26%), Staphylococcus (21%), Acinetobacter (16%), Candida (16%) and Enterobacter (10%). The incidence of multidrug-resistant/extensively drug-resistant (MDR/XDR) organisms was 4.2-fold higher (95% CI 1.3 - 13.4) during H2019 compared with L2020. Logistic regression analysis revealed two independent predictors of nosocomial infection: ICU length of stay (odds ratio (OR) 1.12, 95% CI 1.02 - 1.22) and intercostal drain duration in days (OR 1.27, 95% CI 1.09 - 1.47).

Conclusion

High occupancy in the ICU was associated with an increased risk of HAI and a greater incidence of MDR and XDR pathogens. Increasing ICU length of stay and invasive device duration were independent predictors of HAI.

Contribution of the study

Hospital-acquired infections are a common problem and cause of morbidity and mortality in intensive care units and general wards globally. However, there is very little literature on the topic from low- and middle-income countries. This study aims to provide insite into the unique factors that contribute to these infections in the South African context.

Risk Factors, Pathogens, and Outcomes of Ventilator-Associated Pneumonia in Non-Cardiac Surgical Patients: A Retrospective Analysis

Ventilator-associated pneumonia (VAP) is a critical hospital-acquired infection following non-cardiac surgeries, leading to poor outcomes. This study identifies VAP risk factors in non-cardiac surgical patients and determines the causative pathogens. A retrospective analysis with 1:4 propensity-score matching was conducted on patients in a surgical intensive care unit (ICU) from 2010 to 2020 at a private tertiary medical center. Among 99 VAP patients, the mortality rate was 64.7%. VAP risk factors included prolonged mechanical ventilation (odds ratio [OR] 6.435; p < 0.001), repeat intubation (OR 6.438; p < 0.001), lower oxygenation levels upon ICU admission (OR 0.950; p < 0.001), and undergoing gastrointestinal surgery (OR 2.257; p = 0.021). The 30-day mortality risk factors in the VAP group were late-onset VAP (OR 3.450; p = 0.022), inappropriate antibiotic treatment (OR 4.083; p = 0.041), and undergoing gastrointestinal surgeries (OR 4.776; p = 0.019). Nearly half of the Gram-negative infections were resistant strains, and a third were polymicrobial infections. Non-cardiac surgical patients with VAP face adverse hospital outcomes. Identifying high-risk patients and understanding VAP's resistant and microbial nature are crucial for appropriate treatment and improved health outcomes.

Unravelling the complexity of ventilator-associated pneumonia: a systematic methodological literature review of diagnostic criteria and definitions used in clinical research

BACKGROUND

Ventilator-associated pneumonia (VAP) is a prevalent and grave hospital-acquired infection that affects mechanically ventilated patients. Diverse diagnostic criteria can significantly affect VAP research by complicating the identification and management of the condition, which may also impact clinical management.

OBJECTIVES

We conducted this review to assess the diagnostic criteria and the definitions of the term "ventilator-associated" used in randomised controlled trials (RCTs) of VAP management.

SEARCH METHODS

Based on the protocol (PROSPERO 2019 CRD42019147411), we conducted a systematic search on MEDLINE/PubMed and Cochrane CENTRAL for RCTs, published or registered between 2010 and 2024.

SELECTION CRITERIA

We included completed and ongoing RCTs that assessed pharmacological or non-pharmacological interventions in adults with VAP.

DATA COLLECTION AND SYNTHESIS

Data were collected using a tested extraction sheet, as endorsed by the Cochrane Collaboration. After cross-checking, data were summarised in a narrative and tabular form.

RESULTS

In total, 7,173 records were identified through the literature search. Following the exclusion of records that did not meet the eligibility criteria, 119 studies were included. Diagnostic criteria were provided in 51.2% of studies, and the term "ventilator-associated" was defined in 52.1% of studies. The most frequently included diagnostic criteria were pulmonary infiltrates (96.7%), fever (86.9%), hypothermia (49.1%), sputum (70.5%), and hypoxia (32.8%). The different criteria were used in 38 combinations across studies. The term "ventilator-associated" was defined in nine different ways.

CONCLUSIONS

When provided, diagnostic criteria and definitions of VAP in RCTs display notable variability. Continuous efforts to harmonise VAP diagnostic criteria in future clinical trials are crucial to improve quality of care, enable accurate epidemiological assessments, and guide effective antimicrobial stewardship.

Diagnostic Role of Opsonic Activity in Acinetobacter baumannii Ventilator-Associated Pneumonia

In this study, we investigated the diagnostic value of opsonic activity against Acinetobacter baumannii in Ventilator-Associated Pneumonia (VAP) among 50 patients, compared to 102 negative and positive controls. Out of the 50 patients, only 33 (66 %) were diagnosed with VAP using the Clinical Pulmonary Infection Score (CPIS). The opsonic activity assay demonstrated three key findings: (i) 95 % sensitivity and 91.7 % specificity, with a Receiver Operating Characteristic (ROC) area of 0.976 for distinguishing A. baumannii culture positives from negatives; (ii) 95 % sensitivity and 78.7 % specificity, with a 0.915 ROC area, in differentiating VAP/blood culture positive patients from colonized/negative groups; (iii) An ROC area of 0.553 for VAP and colonization, as identified by CPIS alone, indicating an indeterminate threshold. These results highlight that CPIS, microbiological, and clinical evaluations were not correlated, suggesting that opsonic activity against A. baumannii could be a potential VAP diagnostic tool, with the need for large-scale validations.

Association between lactate dehydrogenase and ventilator-associated pneumonia risk: an analysis of the MIMIC database 2001-2019

BACKGROUND

Serum lactate dehydrogenase (LDH) is a nonspecific inflammatory biomarker and has been reported to be associated with pneumonia prognosis. This study aimed to evaluate the relationship between LDH levels and ventilator-associated pneumonia (VAP) risk in intensive care unit (ICU) patients.

METHODS

This retrospective cohort study used data from the Multiparameter Intelligent Monitoring in Intensive Care database from 2001 to 2019. ICU patients aged ≥ 18 years and receiving mechanical ventilation were included. LDH levels were analyzed as continuous and categorical variables (< 210, 210-279, 279-390, > 390 IU/L), respectively. Restricted cubic spline (RCS) curves and quartiles were used to categorize LDH levels. Logistic regression and linear regression were utilized to assess the relationship of LDH levels with VAP risk and duration of mechanical ventilation, respectively.

RESULTS

A total of 9,164 patients were enrolled, of which 646 (7.05%) patients developed VAP. High levels of LDH increased the risk of VAP [odds ratio (OR) = 1.15, 95% confidence interval (CI): 1.06-1.24] and LDH levels were positively correlated with the duration of mechanical ventilation [β = 4.49, 95%CI: (3.42, 5.56)]. Moreover, patients with LDH levels of 279-390 IU/L (OR = 1.38, 95%CI: 1.08-1.76) and > 390 IU/L (OR = 1.50, 95%CI: 1.18-1.90) had a higher risk of VAP than patients with LDH levels < 210 IU/L. Patients with LDH levels of 279-390 IU/L [β = 3.84, 95%CI: (0.86, 6.82)] and > 390 IU/L [β = 11.22, 95%CI: (8.21, 14.22)] (vs. <210 IU/L) had a longer duration of mechanical ventilation.

CONCLUSION

Elevated serum LDH levels were related to a higher risk of VAP and longer duration of mechanical ventilation and may be useful for monitoring VAP risk.

A Bibliometric Analysis of the Role and Research Trending of Bronchoalveolar Lavage in the Diagnosis and Treatment of Ventilator-Associated Pneumonia

Ventilator-associated pneumonia (VAP) is one of the most common complications in intensive care units (ICUs) and negatively affects patient outcomes. Despite its widespread use as a diagnostic and therapeutic measure, the application and effectiveness of bronchoalveolar lavage (BAL) in the management of VAP require further exploration. This study aimed to evaluate the research dynamics, major trends, and scientific networks of BAL in the diagnosis and treatment of VAP using bibliometric analysis. Literature from the Web of Science database on BAL for the diagnosis and treatment of VAP from 1990 to 2024 was screened and analyzed. Keyword co-occurrence, trend analysis, and citation burst analyses were conducted using CiteSpace to identify research hotspots, core authors, institutions, and countries, as well as the evolution of research domains. The bibliometric analysis included 968 publications. Trend analysis indicated growing interest in BAL techniques, particularly in the categories of RESPIRATORY SYSTEM (burst score: 27.82) and MEDICINE, RESEARCH, and EXPERIMENTAL (burst score: 7.41). The co-citation analysis highlighted influential authors in the field, such as Torres (burst score: 9.35), Croce (burst score: 5.86), and Meduri (burst score: 5.71). Keyword analysis results revealed core clusters in the treatment of VAP with BAL, including "nonbronchoscopic lavage" (silhouette value: 0.703), "ICU-acquired infection" (silhouette value: 0.7), and "ventilator-associated tracheobronchitis" (silhouette value: 0.637). Additionally, geographic analysis showed that North America and Europe dominated the research in this field. Recently, research trends regarding protected specimen brushes and quantitative culture techniques have emerged. This study found broad applications of BAL in VAP management, especially in improving diagnostic accuracy and treatment outcomes. Optimized strategies such as improvement of lavage techniques and multidisciplinary collaboration may emerge as potential research hotspots in the future.

MUltiparametric Score for Ventilation Discontinuation in Intensive Care Patients: A Protocol for an Observational Study

BACKGROUND

Mechanical ventilation significantly improves patient survival but is associated with complications, increasing healthcare costs and morbidity. Identifying optimal weaning times is paramount to minimize these risks, yet current methods rely heavily on clinical judgment, lacking specificity.

METHODS

This study introduces a novel multiparametric predictive score, the MUSVIP (MUltiparametric Score for Ventilation discontinuation in Intensive care Patients), aimed at accurately predicting successful extubation. Conducted at Santo Stefano Hospital's ICU, this single-center, observational, prospective cohort study will span over 12 months, enrolling adult patients undergoing invasive mechanical ventilation. The MUSVIP integrates variables measured before and during a spontaneous breathing trial (SBT) to formulate a predictive score.

RESULTS

Preliminary analyses suggest an Area Under the Curve (AUC) of 0.815 for the MUSVIP, indicating high predictive capacity. By systematically applying this score, we anticipate identifying patients likely to succeed in weaning earlier, potentially reducing ICU length of stay and associated healthcare costs.

CONCLUSION

This study's findings could significantly influence clinical practices, offering a robust, easy-to-use tool for optimizing weaning processes in ICUs.

The Clinical Pulmonary Infection Score Combined with Procalcitonin and Lung Ultrasound (CPIS-PLUS), a Good Tool for Ventilator Associated Pneumonia Early Diagnosis in Pediatrics

Ventilator-associated pneumonia (VAP) is common in Pediatric Intensive Care Units. Although early detection is crucial, current diagnostic methods are not definitive. This study aimed to identify lung ultrasound (LUS) findings and procalcitonin (PCT) values in pediatric patients with VAP to create a new early diagnosis score combined with the Clinical Pulmonary Infection Score (CPIS), the CPIS-PLUS score. Prospective longitudinal and interventional study. Pediatric patients with suspected VAP were included and classified into VAP or non-VAP groups, based on Centers of Disease Control (CDC) criteria for the final diagnosis. A chest-X-ray (CXR), LUS, and blood test were performed within the first 12 h of admission. CPIS score was calculated. A total of 108 patients with VAP suspicion were included, and VAP was finally diagnosed in 51 (47%) patients. CPIS-PLUS showed high accuracy in VAP diagnosis with a sensitivity (Sn) of 80% (95% CI 65-89%) and specificity (Sp) of 73% (95% CI 54-86%). The area under the curve (AUC) resulted in 0.86 for CPIS-PLUS vs. 0.61 for CPIS. In conclusion, this pilot study showed that CPIS-PLUS could be a potential and reliable tool for VAP early diagnosis in pediatric patients. Internal and external validations are needed to confirm the potential value of this score to facilitate VAP diagnosis in pediatric patients.

Chlorhexidine is not effective at any concentration in preventing ventilator-associated pneumonia: a systematic review and network meta-analysis

INTRODUCTION

Oral chlorhexidine has been widely used for ventilator-associated pneumonia prevention in the critical care setting; however, previous studies and evidence synthesis have generated inconsistent findings. Our study aims to investigate if different concentrations of oral chlorhexidine may be effective in preventing such complication in intensive care unit patients.

METHODS

After pre-registration (Open Science Framework: 8CUKF), we conducted a network meta-analysis with the following PICOS: adult patients (age > 18 years old) undergoing invasive mechanical ventilation admitted in ICU (P); any concentration of chlorhexidine used for oral hygiene (I); placebo, sham intervention, usual care, or no intervention (C); rate of VAP (primary outcome), mechanical ventilation length, ICU length of stay (LOS), hospital LOS, mortality (secondary outcomes) (O); randomized controlled trials (S). We used the following database: PubMed, the Cochrane Central Register of Controlled Trials (CENTRAL), Scopus, and EMBASE without any limitation in publication date or language.

RESULTS

Chlorhexidine did not demonstrate any significant advantage over the control group in preventing ventilator-associated pneumonia or reducing mortality, duration of mechanical ventilation, length of stay in the intensive care unit, or overall mortality.

CONCLUSIONS

Chlorhexidine oral decontamination does not reduce the rate of ventilator-associated pneumonia in critically ill adult patients and its routine use could not be recommended.

TRIAL REGISTRATION

Registration number: Open Science Framework: 8CUKF.

Surveillance and prevention of healthcare-associated infections: best practices to prevent ventilator-associated events

INTRODUCTION

Ventilator associated pneumonia (VAP) leads to an increase in morbidity, mortality, and healthcare costs. In addition to increased evidence from the latest European and American guidelines (published in 2017 and 2022, respectively), in the last two years, several important clinical experiences have added new prevention tools to be included to improve the management of VAP.

AREAS COVERED

This paper is a narrative review of new evidence on VAP prevention. We divided VAP prevention measures into pharmacological, non-pharmacological, and ventilator care bundles.

EXPERT OPINION

Most of the effective strategies that have been shown to decrease the incidence of complications are easy to implement and inexpensive. The implementation of care bundles, accompanied by educational measures and a multidisciplinary team should be part of optimal management. In addition to ventilator care bundles for the prevention of VAP, it could possibly be beneficial to use ventilator care bundles for the prevention of noninfectious ventilator associated events.

Ceftriaxone to prevent early ventilator-associated pneumonia in patients with acute brain injury: a multicentre, randomised, double-blind, placebo-controlled, assessor-masked superiority trial

BACKGROUND

Patients with acute brain injury are at high risk of ventilator-associated pneumonia (VAP). The benefit of short-term antibiotic prophylaxis remains debated. We aimed to establish the effect of an early, single dose of the antibiotic ceftriaxone on the incidence of early VAP in patients with severe brain injury who required mechanical ventilation.

METHODS

PROPHY-VAP was a multicentre, randomised, double-blind, placebo-controlled, assessor-masked, superiority trial conducted in nine intensive care units in eight French university hospitals. We randomly assigned comatose (Glasgow Coma Scale score [GCS] ≤12) adult patients (age ≥18 years) who required mechanical ventilation for at least 48 h after acute brain injury to receive intravenous ceftriaxone 2 g or placebo once within the 12 h following tracheal intubation. Participants did not receive selective oropharyngeal and digestive tract decontamination. The primary outcome was the proportion of patients developing early VAP from the 2nd to the 7th day of mechanical ventilation, confirmed by masked assessors. The analysis was reported in the modified intention-to-treat population, which comprised all randomly assigned patients except those who withdrew or did not give consent to continue and those who did not receive the allocated treatment because they met a criterion for non-eligibility. The trial is registered with ClinicalTrials.gov, NCT02265406.

FINDINGS

From Oct 14, 2015, to May 27, 2020, 345 patients were randomly assigned (1:1) to receive ceftriaxone (n=171) or placebo (n=174); 330 received the allocated intervention and 319 were included in the analysis (162 in the ceftriaxone group and 157 in the placebo group). 166 (52%) participants in the analysis were men and 153 (48%) were women. 15 patients did not receive the allocated intervention after randomisation and 11 withdrew their consent. Adjudication confirmed 93 cases of VAP, including 74 early infections. The incidence of early VAP was lower in the ceftriaxone group than in the placebo group (23 [14%] vs 51 [32%]; hazard ratio 0·60 [95% CI 0·38-0·95], p=0·030), with no microbiological impact and no adverse effects attributable to ceftriaxone.

INTERPRETATION

In patients with acute brain injury, a single ceftriaxone dose decreased the risk of early VAP. On the basis of our findings, we recommend that an early, single dose of ceftriaxone be included in all bundles for the prevention of VAP in patients with brain injury who require mechanical ventilation.

FUNDING

French Ministry of Social Affairs and Health.

Efficacy and safety of antibiotics targeting Gram-negative bacteria in nosocomial pneumonia: a systematic review and Bayesian network meta-analysis

BACKGROUND

Multiple randomized controlled studies have compared numerous antibiotic regimens, including new, recently commercialized antibiotics in the treatment of nosocomial pneumonia (NP). The objective of this Bayesian network meta-analysis (NMA) was to compare the efficacy and the safety of different antibiotic treatments for NP.

METHODS

We conducted a systematic search of PubMed, Medline, Web of Science, EMBASE and the Cochrane Library databases from 2000 through 2021. The study selection included studies comparing antibiotics targeting Gram-negative bacilli in the setting of NP. The primary endpoint was 28 day mortality. Secondary outcomes were clinical cure, microbiological cure and adverse events.

RESULTS

Sixteen studies encompassing 4993 patients were included in this analysis comparing 13 antibiotic regimens. The level of evidence for mortality comparisons ranged from very low to moderate. No significant difference in 28 day mortality was found among all beta-lactam regimens. Only the combination of meropenem plus aerosolized colistin was associated with a significant decrease of mortality compared to using intravenous colistin alone (OR = 0.43; 95% credible interval [0.17-0.94]), based on the results of the smallest trial included. The clinical failure rate of ceftazidime was higher than meropenem with (OR = 1.97; 95% CrI [1.19-3.45]) or without aerosolized colistin (OR = 1.40; 95% CrI [1.00-2.01]), imipemen/cilastatin/relebactam (OR = 1.74; 95% CrI [1.03-2.90]) and ceftazidime/avibactam (OR = 1.48; 95% CrI [1.02-2.20]). For microbiological cure, no substantial difference between regimens was found, but ceftolozane/tazobactam had the highest probability of being superior to comparators. In safety analyses, there was no significant difference between treatments for the occurrence of adverse events, but acute kidney failure was more common in patients receiving intravenous colistin.

CONCLUSIONS

This network meta-analysis suggests that most antibiotic regimens, including new combinations and cefiderocol, have similar efficacy and safety in treating susceptible Gram-negative bacilli in NP. Further studies are necessary for NP caused by multidrug-resistant bacteria. Registration PROSPERO CRD42021226603.

An agent-based model on antimicrobial de-escalation in intensive care units: Implications on clinical trial design

Antimicrobial de-escalation refers to reducing the spectrum of antibiotics used in treating bacterial infections. This strategy is widely recommended in many antimicrobial stewardship programs and is believed to reduce patients' exposure to broad-spectrum antibiotics and prevent resistance. However, the ecological benefits of de-escalation have not been universally observed in clinical studies. This paper conducts computer simulations to assess the ecological effects of de-escalation on the resistance prevalence of Pseudomonas aeruginosa-a frequent pathogen causing nosocomial infections. Synthetic data produced by the models are then used to estimate the sample size and study period needed to observe the predicted effects in clinical trials. Our results show that de-escalation can reduce colonization and infections caused by bacterial strains resistant to the empiric antibiotic, limit the use of broad-spectrum antibiotics, and avoid inappropriate empiric therapies. Further, we show that de-escalation could reduce the overall super-infection incidence, and this benefit becomes more evident under good compliance with hand hygiene protocols among health care workers. Finally, we find that any clinical study aiming to observe the essential effects of de-escalation should involve at least ten arms and last for four years-a size never attained in prior studies. This study explains the controversial findings of de-escalation in previous clinical studies and illustrates how mathematical models can inform outcome expectations and guide the design of clinical studies.

Ventilator Weaning and Extubation

Increasing evidence supports specific approaches to liberate patients from invasive ventilation including the use of liberation protocols, inspiratory assistance during spontaneous breathing trials (SBTs), early extubation of patients with chronic obstructive pulmonary disease to noninvasive ventilation, and prophylactic use of noninvasive support strategies after extubation. Additional research is needed to elucidate the best criteria to identify patients who are ready to undergo an SBT and to inform optimal screening frequency, the best SBT technique and duration, extubation assessments, and extubation decision-making. Additional clarity is also needed regarding the optimal timing to measure and report extubation success.

Clinical evaluation of the BioFire Respiratory Pathogen Panel for the guidance of empirical antimicrobial therapy in critically ill patients with hospital-acquired pneumonia: A multicenter, quality improvement project

BACKGROUND

We aimed to determine whether implementing antimicrobial stewardship based on multiplex bacterial PCR examination of respiratory fluid can enhance outcomes of critically ill patients with hospital-acquired pneumonia (HAP).

METHODS

We conducted a quality improvement study in two hospitals in France. Adult patients requiring invasive mechanical ventilation with a diagnosis of HAP were included. In the pre-intervention period (August 2019 to April 2020), antimicrobial therapy followed European guidelines. In the «intervention» phase (June 2020 to October 2021), treatment followed a multiplex PCR-guided protocol. The primary endpoint was a composite endpoint made of mortality on day 28, clinical cure between days 7 and 10, and duration of invasive mechanical ventilation on day 28. The primary outcome was analyzed with a DOOR strategy.

RESULTS

A total of 443 patients were included in 3 ICUs from 2 hospitals (220 pre-intervention; 223 intervention). No difference in the ranking of the primary composite outcome was found (DOOR: 50.3%; 95%CI, 49.9%-50.8%). The number of invasive mechanical ventilation-free days at day 28 was 10.0 [0.0; 19.0] in the baseline period and 9.0 [0.0; 20.0] days during the intervention period (p = 0.95). The time-to-efficient antimicrobial treatment was 0.43 ± 1.29 days before versus 0.55 ± 1.13 days after the intervention (p = 0.56).

CONCLUSION

Implementation of Rapid Multiplex PCR to guide empirical antimicrobial therapy for critically ill patients with HAP was not associated with better outcomes. However, adherence to stewardship was low, and the study may have had limited power to detect a clinically important difference.

Clinically used broad-spectrum antibiotics compromise inflammatory monocyte-dependent antibacterial defense in the lung

Hospital-acquired pneumonia (HAP) is associated with high mortality and costs, and frequently caused by multidrug-resistant (MDR) bacteria. Although prior antimicrobial therapy is a major risk factor for HAP, the underlying mechanism remains incompletely understood. Here, we demonstrate that antibiotic therapy in hospitalized patients is associated with decreased diversity of the gut microbiome and depletion of short-chain fatty acid (SCFA) producers. Infection experiments with mice transplanted with patient fecal material reveal that these antibiotic-induced microbiota perturbations impair pulmonary defense against MDR Klebsiella pneumoniae. This is dependent on inflammatory monocytes (IMs), whose fatty acid receptor (FFAR)2/3-controlled and phagolysosome-dependent antibacterial activity is compromized in mice transplanted with antibiotic-associated patient microbiota. Collectively, we characterize how clinically relevant antibiotics affect antimicrobial defense in the context of human microbiota, and reveal a critical impairment of IM´s antimicrobial activity. Our study provides additional arguments for the rational use of antibiotics and offers mechanistic insights for the development of novel prophylactic strategies to protect high-risk patients from HAP.

Hospital-acquired and ventilator-associated pneumonia caused by multidrug-resistant Gram-negative pathogens: Understanding epidemiology, resistance patterns, and implications with COVID-19

The ongoing spread of antimicrobial resistance has complicated the treatment of bacterial hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP). Gram-negative pathogens, especially those with multidrug-resistant profiles, including Escherichia coli, Klebsiella pneumoniae, Enterobacter spp., Pseudomonas aeruginosa, and Acinetobacter spp., are important culprits in this type of infections. Understanding the determinants of resistance in pathogens causing pneumonia is ultimately stressing, especially in the shadows of the COVID-19 pandemic, when bacterial lung infections are considered a top priority that has become urgent to revise. Globally, the increasing prevalence of these pathogens in respiratory samples represents a significant infection challenge, with major limitations of treatment options and poor clinical outcomes. This review will focus on the epidemiology of HAP and VAP and will present the roles and the antimicrobial resistance patterns of implicated multidrug-resistant (MDR) Gram-negative pathogens like carbapenem-resistant Acinetobacter baumannii (CRAB), carbapenem-resistant Pseudomonas aeruginosa (CRPA), carbapenem-resistant Enterobacterales (CRE), as well as colistin-resistant Gram-negative pathogens and extended-spectrum β-lactamase (ESBL)-producing Enterobacterales. While emerging from the COVID-19 pandemic, perspectives and conclusions are drawn from findings of HAP and VAP caused by MDR Gram-negative bacteria in patients with COVID-19.

Epidemiology and Burden of Ventilator-Associated Pneumonia among Adult Intensive Care Unit Patients: A Portuguese, Multicenter, Retrospective Study (eVAP-PT Study)

Ventilator-associated pneumonia (VAP) is a prevailing nosocomial infection in critically ill patients requiring invasive mechanical ventilation (iMV). The impact of VAP is profound, adversely affecting patient outcomes and placing a significant burden on healthcare resources. This study assessed for the first time the contemporary VAP epidemiology in Portugal and its burden on the healthcare system and clinical outcomes. Additionally, resource consumption (duration of iMV, intensive care unit (ICU), hospital length of stay (LOS)) and empirical antimicrobial therapy were also evaluated. This multicenter, retrospective study included patients admitted to the hospital between July 2016 and December 2017 in a participating ICU, who underwent iMV for at least 48 h. Patients with a VAP diagnosis were segregated for further analysis (n = 197). Control patients, ventilated for >48 h but without a VAP diagnosis, were also included in a 1:1 ratio. Cumulative VAP incidence was computed. All-cause mortality was assessed at 28, 90, and 365 days after ICU admission. Cumulative VAP incidence was 9.2% (95% CI 8.0-10.5). The all-cause mortality rate in VAP patients was 24.9%, 34.0%, and 40.6%, respectively, and these values were similar to those observed in patients without VAP diagnosis. Further, patients with VAP had significantly longer ICU (27.5 vs. 11.0 days, p < 0.001) and hospital LOS (61 vs. 35.9 days, p < 0.001), more time under iMV (20.7 vs. 8.0 days, p < 0.001) and were more often subjected to tracheostomy (36.5 vs. 14.2%; p < 0.001). Patients with VAP who received inappropriate empirical antimicrobials had higher 28-day mortality, 34.3% vs. 19.5% (odds ratio 2.16, 95% CI 1.10-4.23), although the same was not independently associated with 1-year all-cause mortality (p = 0.107). This study described the VAP impact and burden on the Portuguese healthcare system, with approximately 9% of patients undergoing iMV for >48 h developing VAP, leading to increased resource consumption (longer ICU and hospital LOS). An unexpectedly high incidence of inappropriate, empirical antimicrobial therapy was also noted, being positively associated with a higher mortality risk of these patients. Knowledge of the Portuguese epidemiology characterization of VAP and its multidimensional impact is essential for efficient treatment and optimized long-term health outcomes of these patients.

Intrapulmonary and Systemic Pharmacokinetics of Colistin Following Nebulization of Low-Dose Colistimethate Sodium in Patients with Ventilator-Associated Pneumonia Caused by Carbapenem-Resistant Acinetobacter baumannii

Colistimethate sodium (CMS) nebulization is associated with reduced systemic toxicity compared to intravenous injection, with potentially enhanced clinical efficacy. This study aimed to assess the pharmacokinetic (PK) properties of colistin during low-dose CMS nebulization in patients with ventilator-associated pneumonia (VAP) caused by carbapenem-resistant Acinetobacter baumannii. A nonlinear mixed-effects modeling approach was applied to develop population PK models for colistin in both epithelial lining fluid (ELF) and plasma. Twenty patients participated, and 80 ELF and 100 plasma samples were used for model development. Median colistin concentrations measured in ELF were 614-fold, 408-fold, and 250-fold higher than in plasma at 1, 3, and 5 h, respectively. Time courses in both ELF and plasma were best described by a one-compartment model with a Weibull absorption process. When the final model was simulated, the maximum free concentration and area under the free colistin concentration-time curve at steady state over 24 h in the plasma were approximately 1/90 and 1/50 of the corresponding values in ELF at steady state, respectively. For an A. baumannii MIC of 1 mg/L, inhaling 75 mg of CMS at 6 h intervals was deemed appropriate, with dose adjustments needed for MICs exceeding 2 mg/L. Using a nebulizer for CMS resulted in a notably higher exposure of colistin in the ELF than plasma, indicating the potential of nebulization to reduce systemic toxicity while effectively treating VAP.

Management of Ventilator-Associated Pneumonia: Guidelines

Two recent major guidelines on diagnosis and treatment of ventilator-associated pneumonia (VAP) recommend consideration of local antibiotic resistance patterns and individual patient risks for resistant pathogens when formulating an initial empiric antibiotic regimen. One recommends against invasive diagnostic techniques with quantitative cultures to determine the cause of VAP; the other recommends either invasive or noninvasive techniques. Both guidelines recommend short-course therapy be used for most patients with VAP. Although neither guideline recommends use of procalcitonin as an adjunct to clinical judgment when diagnosing VAP, they differ with respect to use of serial procalcitonin to shorten the length of antibiotic treatment.

Relevance of Protein Intake for Weaning in the Mechanically Ventilated Critically Ill: Analysis of a Large International Database

OBJECTIVES

The association between protein intake and the need for mechanical ventilation (MV) is controversial. We aimed to investigate the associations between protein intake and outcomes in ventilated critically ill patients.

DESIGN

Analysis of a subset of a large international point prevalence survey of nutritional practice in ICUs.

SETTING

A total of 785 international ICUs.

PATIENTS

A total of 12,930 patients had been in the ICU for at least 96 hours and required MV by the fourth day after ICU admission at the latest.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We modeled associations between the adjusted hazard rate (aHR) of death in patients requiring MV and successful weaning (competing risks), and three categories of protein intake (low: < 0.8 g/kg/d, standard: 0.8-1.2 g/kg/d, high: > 1.2 g/kg/d). We compared five different hypothetical protein diets (an exclusively low protein intake, a standard protein intake given early (days 1-4) or late (days 5-11) after ICU admission, and an early or late high protein intake). There was no evidence that the level of protein intake was associated with time to weaning. However, compared with an exclusively low protein intake, a standard protein intake was associated with a lower hazard of death in MV: minimum aHR 0.60 (95% CI, 0.45-0.80). With an early high intake, there was a trend to a higher risk of death in patients requiring MV: maximum aHR 1.35 (95% CI, 0.99-1.85) compared with a standard diet.

CONCLUSIONS

The duration of MV does not appear to depend on protein intake, whereas mortality in patients requiring MV may be improved by a standard protein intake. Adverse effects of a high protein intake cannot be excluded.

Efficacy of preventive interventions against ventilator-associated pneumonia in critically ill patients: an umbrella review of meta-analyses

Many meta-analyses have assessed the efficacy of preventive interventions against ventilator-associated pneumonia (VAP) in critically ill patients. However, there has been no comprehensive analysis of the strength and quality of evidence to date. Systematic reviews of randomized and quasi-randomized controlled trials, which evaluated the effect of preventive strategies on the incidence of VAP in critically ill patients receiving mechanical ventilation for at least 48 h, were included in this article. We identified a total of 34 interventions derived from 31 studies. Among these interventions, 19 resulted in a significantly reduced incidence of VAP. Among numerous strategies, only selective decontamination of the digestive tract (SDD) was supported by highly suggestive (Class II) evidence (risk ratio (RR)=0.439, 95% CI: 0.362-0.532). Based on data from the sensitivity analysis, the evidence for the efficacy of non-invasive ventilation in weaning from mechanical ventilation (NIV) was upgraded from weak (Class IV) to highly suggestive (Class II) (RR=0.32, 95% CI: 0.22-0.46). All preventive interventions were not supported by robust evidence for reducing mortality. Early mobilization exhibited suggestive (Class III) evidence in shortening both intensive length of stay (LOS) in the intensive care unit (ICU) (mean difference (MD)=-0.85, 95% CI: -1.21 to -0.49) and duration of mechanical ventilation (MD=-1.02, 95% CI: -1.41 to -0.63). In conclusion, SDD and NIV are supported by robust evidence for prevention against VAP, while early mobilization has been shown to significantly shorten the LOS in the ICU and the duration of mechanical ventilation. These three strategies are recommendable for inclusion in the ventilator bundle to lower the risk of VAP and improve the prognosis of critically ill patients.

Carbapenem vs. non-carbapenem antibiotics for ventilator-associated pneumonia: A systematic review with meta-analysis

BACKGROUND

Carbapenem is recommended as one of the first-line regimens for ventilator-associated pneumonia (VAP), but no recent systematic review has fully investigated its efficacy. This systematic review aims to evaluate the efficacy of carbapenem compared with non-carbapenem for VAP treatment.

METHODS

We performed a systematic review and meta-analysis of studies comparing the efficacy and the safety between carbapenem and non-carbapenem with activity to Pseudomonas aeruginosa in the treatment for VAP. The main outcome was mortality, and the additional outcomes were the clinical cure of pneumonia, length of intensive care unit stay, recurrence, adverse effects, and the development of resistant bacteria. This study was conducted in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines.

RESULTS

Of the initial 1,730 publications, 9 randomized control trials were enrolled. In the meta-analysis, no difference was observed between the carbapenem and non-carbapenem regimens in improving mortality (odds ratio, 0.83; 95 % confidence interval (CI) 0.67-1.02). While the carbapenem regimen was superior to the non-carbapenem regimen in studies reporting the resolution of pneumonia (odds ratio, 1.09; 95 % CI 1.01-1.17), the effectiveness of carbapenem treatment was not evident in studies assessing the other outcomes.

CONCLUSIONS

Carbapenem might have no superiority in survival when treating VAP. Moreover, non-carbapenem antibiotics with activities to P. aeruginosa have a potential option to avoid inducing carbapenem-resistant pathogens.

Is Zero Ventilator-Associated Pneumonia Achievable? Updated Practical Approaches to Ventilator-Associated Pneumonia Prevention

Ventilator-associated pneumonia (VAP) remains a significant clinical entity with reported incidence rates of 7% to 15%. Given the considerable adverse consequences associated with this infection, VAP prevention became a core measure required in most US hospitals. Many institutions took pride in implementing effective VAP prevention bundles that combined at least head of bed elevation, hand hygiene, chlorhexidine oral care, and subglottic drainage. Spontaneous breathing and awakening trials have also consistently been shown to shorten the duration of mechanical ventilation and secondarily reduce the occurrence of VAP.

Healthcare-associated infections in patients with severe COVID-19 supported with extracorporeal membrane oxygenation: a nationwide cohort study

BACKGROUND

Both critically ill patients with coronavirus disease 2019 (COVID-19) and patients receiving extracorporeal membrane oxygenation (ECMO) support exhibit a high incidence of healthcare-associated infections (HAI). However, data on incidence, microbiology, resistance patterns, and the impact of HAI on outcomes in patients receiving ECMO for severe COVID-19 remain limited. We aimed to report HAI incidence and microbiology in patients receiving ECMO for severe COVID-19 and to evaluate the impact of ECMO-associated infections (ECMO-AI) on in-hospital mortality.

METHODS

For this study, we analyzed data from 701 patients included in the ECMOSARS registry which included COVID-19 patients supported by ECMO in France.

RESULTS

Among 602 analyzed patients for whom HAI and hospital mortality data were available, 214 (36%) had ECMO-AI, resulting in an incidence rate of 27 ECMO-AI per 1000 ECMO days at risk. Of these, 154 patients had bloodstream infection (BSI) and 117 patients had ventilator-associated pneumonia (VAP). The responsible microorganisms were Enterobacteriaceae (34% for BSI and 48% for VAP), Enterococcus species (25% and 6%, respectively) and non-fermenting Gram-negative bacilli (13% and 20%, respectively). Fungal infections were also observed (10% for BSI and 3% for VAP), as were multidrug-resistant organisms (21% and 15%, respectively). Using a Cox multistate model, ECMO-AI were not found associated with hospital death (HR = 1.00 95% CI [0.79-1.26], p = 0.986).

CONCLUSIONS

In a nationwide cohort of COVID-19 patients receiving ECMO support, we observed a high incidence of ECMO-AI. ECMO-AI were not found associated with hospital death. Trial registration number NCT04397588 (May 21, 2020).

Epidemiology of ventilator-associated tracheobronchitis and ventilator-associated pneumonia caused by multidrug-resistant Gram-negative bacteria at a tertiary care hospital in Thailand

Objectives

To investigate the epidemiology of MDR Gram-negative bacilli ventilator-associated tracheobronchitis (MDR GNB-VAT) and MDR GNB ventilator-associated pneumonia (MDR GNB-VAP) among mechanically ventilated patients.

Methods

We conducted a retrospective observational study among hospitalized patients who underwent continuous mechanical ventilation for ≥48 h at Siriraj Hospital, Thailand.

Results

During the 18 month study period, 1824 unique patients underwent continuous mechanical ventilation (12 216 ventilator-days). The cumulative incidences of MDR GNB-VAT and -VAP were 8.4% and 8.3%, respectively. The incidence rates of MDR GNB-VAT and -VAP were 12.52 and 12.44 episodes/1000 ventilator-days, respectively. Among those with VAT, the cumulative incidence and incidence rate of subsequent VAP development within 7 days were 11.76% and 2.81 episodes/1000 ventilator-days, respectively. The median durations of mechanical ventilation before having VAP and VAT were 9 and 12 days, respectively. Multivariate analysis identified three independently associated factors for patients having VAP compared with having VAT: underlying cerebrovascular disease [adjusted OR (aOR): 0.46; 95% CI: 0.27-0.78; P = 0.04], previous surgery (aOR: 0.68; 95% CI: 0.57-0.8; P < 0.001) and acute renal failure (aOR: 1.75; 95% CI: 1.27-2.40; P = 0.001).

Conclusions

The study revealed high incidences of MDR GNB-VAT and -VAP among mechanically ventilated patients. The independent risk factors for having VAP can help identify patients at risk for developing VAP and who need early weaning from mechanical ventilation.

The Effect of Ventilator-Associated Pneumonia on the Time-to-Extubation in Adult and Pediatric Intensive Care Unit Patients Requiring Mechanical Ventilation: A Retrospective Cohort Study

INTRODUCTION

Ventilator-associated pneumonia (VAP) ranks as a prominent hospital-acquired infection. VAP has been shown to have a detrimental impact on patients and healthcare facilities, leading to extended hospital stays, increased demands on medical resources, and higher financial expenses. This study aims to assess the influence of VAP on time-to-extubation and length of hospital stay (LOS) in patients requiring mechanical ventilation for more than 48 hours in pediatric and adult intensive care units (ICU).

METHODS

This retrospective cohort study included adult and pediatric ICU patients admitted to King Abdul-Aziz Medical City in Jeddah, Saudi Arabia, from June 2016 to May 2020. The study encompassed ICU patients who required mechanical ventilation for more than 48 hours. Time-to-extubation and LOS were measured in days and compared between those who developed VAP and those who did not. A Kaplan-Meier curve was employed to estimate and compare both groups' survival functions (time-to-event).

RESULTS

The study involved 367 subjects, with 226 adults and 141 pediatric patients. Among the 367 mechanically ventilated patients, 33 (8.99%) developed VAP during their ICU stay, with 9 of them being children. VAP patients experienced a significantly longer time to extubation than non-VAP patients (13.5 vs. six days, p<0.0001). Likewise, ICU stays for VAP patients were significantly longer than those for non-VAP patients (19.5 vs. 13 days, p<0.002). However, the mortality rate at 28 days from intubation did not exhibit significant differences between the VAP and non-VAP groups (36.36% vs. 27.54%, p=0.283).

CONCLUSION

This study underscores that VAP patients face a substantial delay in time-to-extubation and an increased length of ICU stay compared to non-VAP patients. Such findings substantially impact the cost of hospital care and the risk of exposure to other infection-related complications while under mechanical ventilation. Enhanced preventive measures are warranted to reduce the occurrence and consequences of VAP.