Impact of appropriate antimicrobial treatment on transition from ventilator-associated tracheobronchitis to ventilator-associated pneumonia

VATICAN (Ventilator-Associated Tracheobronchitis Initiative to Conduct Antibiotic Evaluation): protocol for a multicenter randomized open-label trial of watchful waiting versus antimicrobial therapy for ventilator-associated tracheobronchitis

BACKGROUND

Ventilator-associated tracheobronchitis is a common condition among invasively ventilated patients in intensive care units, for which the best treatment strategy is currently unknown. We designed the VATICAN (Ventilator-Associated Tracheobronchitis Initiative to Conduct Antibiotic Evaluation) trial to assess whether a watchful waiting antibiotic treatment strategy is noninferior to routine antibiotic treatment for ventilator-associated tracheobronchitis regarding days free of mechanical ventilation.

METHODS

VATICAN is a randomized, controlled, open-label, multicenter noninferiority trial. Patients with suspected ventilator-associated tracheobronchitis without evidence of ventilator-associated pneumonia or hemodynamic instability due to probable infection will be assigned to either a watchful waiting strategy, without antimicrobial administration for ventilator-associated tracheobronchitis and prescription of antimicrobials only in cases of ventilator-associated pneumonia, sepsis or septic shock, or another infectious diagnosis, or to a routine antimicrobial treatment strategy for seven days. The primary outcome will be mechanical ventilation-free days at 28 days, and a key secondary outcome will be ventilator-associated pneumonia-free survival. Through an intention-to-treat framework with a per-protocol sensitivity analysis, the primary outcome analysis will address noninferiority with a 20% margin, which translates to a 1.5 difference in ventilator-free days. Other analyses will follow a superiority analysis framework.

CONCLUSION

The VATICAN trial will follow all national and international ethical standards. We aim to publish the trial in a high-visibility general journal and present it at critical care and infectious disease conferences for dissemination. These results will likely be immediately applicable to the bedside upon trial completion and will provide information with a low risk of bias for guideline development.

Outcomes associated with ventilator-associated events (VAE), respiratory infections (VARI), pneumonia (VAP) and tracheobronchitis (VAT) in ventilated pediatric ICU patients: A multicentre prospective cohort study

OBJECTIVES

An objective categorization of respiratory infections based on outcomes is an unmet clinical need. Ventilator-associated pneumonia and tracheobronchitis remain used in clinical practice, whereas ventilator-associated events (VAE) are limited to surveillance purposes.

RESEARCH METHODOLOGY/DESIGN

This was a secondary analysis from a multicentre observational prospective cohort study. VAE were defined as a sustained increase in minimum Oxygen inspired fraction (FiO2) and/or Positive end-expiratory pressures (PEEP) of ≥ 0.2/2 cm H2O respectively, or an increase of 0.15 FiO2 + 1 cm H20 positive end-expiratory pressures for ≥ 1 calendar-day.

SETTING

15 Paediatric Intensive Care Units.

MAIN OUTCOME MEASURES

Mechanical ventilation duration, intensive care and hospital length of stay; (LOS) and mortality.

RESULTS

A cohort of 391 ventilated children with an age (median, [Interquartile Ranges]) of 1 year[0.2-5.3] and 7 days[5-10] of mechanical ventilation were included. Intensive care and hospital stays were 11 [7-19] and 21 [14-39] days, respectively. Mortality was 5.9 %. Fifty-eight ventilator-associated respiratory infections were documented among 57 patients: Seventeen (29.3 %) qualified as ventilator-associated pneumonia (VAP) and 41 (70.7 %) as ventilator-associated tracheobronchitis (VAT). Eight pneumonias and 16 tracheobronchitis (47 % vs 39 %,P = 0.571) required positive end-expiratory pressure or oxygen increases consistent with ventilator-associated criteria. Pneumonias did not significantly impact on outcomes when compared to tracheobronchitis. In contrast, infections (pneumonia or tracheobronchitis) following VAEs criteria were associated with > 6, 8 and 15 extra-days of ventilation (16 vs 9.5, P = 0.001), intensive care stay (23.5 vs 15; P = 0.004) and hospital stay (39 vs 24; P = 0.015), respectively.

CONCLUSION

When assessing ventilated children with respiratory infections, VAE apparently is associated with higher ventilator-dependency and LOS compared with pneumonia or tracheobronchitis.

IMPLICATIONS FOR PRACTICE

Incorporating the modification of ventilatory settings for further categorization of the respiratory infections may facilitate therapeutic management among ventilated patients.

Hemorrhagic bronchitis caused by carbapenem-resistant Acinetobacter baumannii infection: A case report

Carbapenem-resistant Acinetobacter baumannii (CR-AB) is rarely found in community respiratory infections, and there are currently no reports of hemorrhagic bronchitis caused by its infection. This work presents a case of bronchial bleeding in a diabetic patient who acquired a community-acquired infection of CR-AB. Treatment with levofloxacin was unsuccessful, as the patient's hemoptysis symptoms recur. The patient was treated with minocycline based on the drug sensitivity test, resulting in the disappearance of hemoptysis symptoms. The patient was subjected to follow-up by phone for three months and did not experience any further hemoptysis symptoms. This case highlights that CR-AB infection causes hemorrhagic bronchitis, and the antimicrobial treatment should be based on drug sensitivity results.

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.

Ventilator-Associated Pneumonia in Immunosuppressed Patients

Immunocompromised patients-including patients with cancer, hematological malignancies, solid organ transplants and individuals receiving immunosuppressive therapies for autoimmune diseases-account for an increasing proportion of critically-ill patients. While their prognosis has improved markedly in the last decades, they remain at increased risk of healthcare- and intensive care unit (ICU)-acquired infections. The most frequent of these are ventilator-associated lower respiratory tract infections (VA-LTRI), which include ventilator-associated pneumonia (VAP) and tracheobronchitis (VAT). Recent studies have shed light on some of the specific features of VAP and VAT in immunocompromised patients, which is the subject of this narrative review. Contrary to previous belief, the incidence of VAP and VAT might actually be lower in immunocompromised than non-immunocompromised patients. Further, the relationship between immunosuppression and the incidence of VAP and VAT related to multidrug-resistant (MDR) bacteria has also been challenged recently. Etiological diagnosis is essential to select the most appropriate treatment, and the role of invasive sampling, specifically bronchoscopy with bronchoalveolar lavage, as well as new molecular syndromic diagnostic tools will be discussed. While bacteria-especially gram negative bacteria-are the most commonly isolated pathogens in VAP and VAT, several opportunistic pathogens are a special concern among immunocompromised patients, and must be included in the diagnostic workup. Finally, the impact of immunosuppression on VAP and VAT outcomes will be examined in view of recent papers using improved statistical methodologies and treatment options-more specifically empirical antibiotic regimens-will be discussed in light of recent findings on the epidemiology of MDR bacteria in this population.

Treatment of Acinetobacter baumannii severe infections

Acinetobacter baumannii is a Gram-negative, multidrug-resistant (MDR) pathogen that causes nosocomial infections, especially in intensive care units (ICUs) and immunocompromised patients. A. baumannii has developed a broad spectrum of antimicrobial resistance, associated with a higher mortality rate among infected patients compared with other non-baumannii species. In terms of clinical impact, resistant strains are associated with increases in both in-hospital length of stay and mortality. A. baumannii can cause a variety of infections, especially ventilator-associated pneumonia, bacteremia, and skin wound infections, among others. The most common risk factors for the acquisition of MDR A. baumannii are previous antibiotic use, mechanical ventilation, length of ICU and hospital stay, severity of illness, and use of medical devices. Current efforts are focused on addressing all the antimicrobial resistance mechanisms described in A. baumannii, with the objective of identifying the most promising therapeutic scheme.

Factors Associated With Choriocarcinoma Syndrome Development in Poor-Risk Patients With Germ Cell Tumors

Background

Germ cell tumors (GCTs) represent a highly curable cancer. However, a small proportion of poor-risk patients can develop choriocarcinoma syndrome (CS) connected with acute respiratory distress syndrome (ARDS) with a high mortality rate. Our retrospective study aimed to determine the risk factors of poor-risk GCTs susceptible to CS development.

Patients and Methods

Using a computerized database and a systematic chart review, we identified the records of 532 patients with GCTs treated at the National Cancer Institute from 2000 to 2018. Ninety eligible patients with poor-risk GCTs based on IGCCCG classification were identified. All patients were treated with platinum-based induction chemotherapy. Clinicopathological variables were collected and analyzed in correlation with CS development.

Results

Nine (10%) of 90 patients developed CS in a median of 1 day (1-9 days) after chemotherapy administration. All patients died shortly after the chemotherapy start with a median of 4 days (3-35 days) due to ARDS development. In univariate analysis, metastatic lung involvement ≥50% of lung parenchyma, choriocarcinoma elements in histology specimen, dyspnea, cough, hemoptysis, ECOG PS ≥2, weight loss, hemoglobin ≤100 g/l, and NLR ≥3.3 at the time of presentation were associated with CS development. In multivariate analysis, ECOG PS ≥2 and metastatic lung involvement ≥50% were independently associated with CS. All patients with these two characteristics developed CS, compared to 0% with zero or one of these factors (p < 0.000001).

Conclusions

In our study, we identified factors associated with CS development. These factors might improve the risk stratification of the patients susceptible to CS and improve their outcome.

Enteral antipseudomonal fluoroquinolones for ventilator-associated tracheobronchitis in children with pre-existing tracheostomy

INTRODUCTION

Pseudomonas aeruginosa is the most commonly isolated organism in tracheostomy-dependent children with ventilator-associated tracheobronchitis (VAT). Enteral treatment with an antipseudomonal fluoroquinolone such as ciprofloxacin or levofloxacin is sometimes employed, but supportive data are limited. The purpose of this study was to evaluate the effectiveness and safety of enteral antipseudomonal fluoroquinolones for VAT in children with pre-existing tracheostomy.

METHODS

This was a retrospective review of electronic medical records for tracheostomy-dependent children <18 years of age who received an enteral antipseduomonal fluoroquinolone for the treatment of presumed VAT from January 2013 through January 2020 at an academic children's hospital.

RESULTS

Seventy-six treatment courses representing 60 children (median age: 9.5, interquartile range [IQR]: 3.6-13.1 years) received an antipseudomonal fluoroquinolone for VAT treatment during the study period. Median treatment duration was 8 (range: 7-10) days. Most tracheostomy cultures (n = 70/82, 85%) were polymicrobial, with P. aeruginosa most commonly isolated (n = 67/224 organisms, 30%). Sixty-five courses (86%) were successfully treated with an enteral fluoroquinolone. Antibiotics were changed or extended for two (3%) children. Antibiotics were prescribed for 10 (13%) courses and eight (11%) required hospitalization for a respiratory infection within 30 days of fluoroquinolone completion. Six (8%) courses received a seizure rescue medication, seven (9%) experienced emesis, and one (1%) had elevated transaminases. Tendonitis and tendon rupture were not observed.

CONCLUSIONS

The results of this study suggest enteral antipseudomonal fluoroquinolones may be effective for the treatment of VAT in children with tracheostomy. Further study is warranted to clarify the role of these agents in pediatric VAT.

A Narrative Review on the Approach to Antimicrobial Use in Ventilated Patients with Multidrug Resistant Organisms in Respiratory Samples—To Treat or Not to Treat? That Is the Question

Multidrug resistant organisms (MDRO) are commonly isolated in respiratory specimens taken from mechanically ventilated patients. The purpose of this narrative review is to discuss the approach to antimicrobial prescription in ventilated patients who have grown a new MDRO isolate in their respiratory specimen. A MEDLINE and PubMed literature search using keywords “multidrug resistant organisms”, “ventilator-associated pneumonia” and “decision making”, “treatment” or “strategy” was used to identify 329 references as background for this review. Lack of universally accepted diagnostic criteria for ventilator-associated pneumonia, or ventilator-associated tracheobronchitis complicates treatment decisions. Consideration of the clinical context including signs of respiratory infection or deterioration in respiratory or other organ function is essential. The higher the quality of respiratory specimens or the presence of bacteremia would suggest the MDRO is a true pathogen, rather than colonization, and warrants antimicrobial therapy. A patient with higher severity of illness has lower safety margins and may require initiation of antimicrobial therapy until an alternative diagnosis is established. A structured approach to the decision to treat with antimicrobial therapy is proposed.

"HAP and VAP after Guidelines"

Nosocomial pneumonia is associated with worsened prognosis when diagnosed in intensive care unit (ICU), ranging from 12 to 48% mortality. The incidence rate of ventilation-acquired pneumonia tends to decrease below 15/1,000 intubation-day. Still, international guidelines are heterogeneous about diagnostic criteria because of inaccuracy of available methods. New entities have thus emerged concerning lower respiratory tract infection, namely ventilation-acquired tracheobronchitis (VAT), or ICU-acquired pneumonia (ICUAP), eventually requiring invasive ventilation (v-ICUAP), according to the type of ventilation support. The potential discrepancy with non-invasive methods could finally lead to underdiagnosis in almost two-thirds of non-intubated patients. Delayed diagnostic could explain in part the 2-fold increase in mortality of penumonia when invasive ventilation is initiated. Here we discuss the rationale underlying this new classification.Many situations can lead to misdiagnosis, even more when the invasive mechanical ventilation is initiated. The chest radiography lacks sntivity and specificity for diagnosing pneumonia. The place of chest computed tomography and lung ultrasonography for routine diagnostic of new plumonary infiltrate remain to be evaluated.Microbiological methods used to confirm the diagnostic can be heterogeneous. The development of molecular diagnostic tools may improve the adequacy of antimicrobial therapies of ventilated patients with pneumonia, but we need to further assess its impact in non-ventilated pneumonia.In this review we introduce distinction between hospital-acquired pneumonia according to the localization in the hospital and the oxygenation/ventilation mode. A clarification of definition is the first step to develop more accurate diagnostic strategies and to improve the patients' prognosis.

Inhaled amikacin versus placebo to prevent ventilator-associated pneumonia: the AMIKINHAL double-blind multicentre randomised controlled trial protocol

INTRODUCTION

Pre-emptive inhaled antibiotics may be effective to reduce the occurrence of ventilator-associated pneumonia among critically ill patients. Meta-analysis of small sample size trials showed a favourable signal. Inhaled antibiotics are associated with a reduced emergence of antibiotic resistant bacteria. The aim of this trial is to evaluate the benefit of a 3-day course of inhaled antibiotics among patients undergoing invasive mechanical ventilation for more than 3 days on the occurrence of ventilator-associated pneumonia.

METHODS AND ANALYSIS

Academic, investigator-initiated, parallel two group arms, double-blind, multicentre superiority randomised controlled trial. Patients invasively ventilated more than 3 days will be randomised to receive 20 mg/kg inhaled amikacin daily for 3 days or inhaled placebo (0.9% Sodium Chloride). Occurrence of ventilator-associated pneumonia will be recorded based on a standardised diagnostic framework from randomisation to day 28 and adjudicated by a centralised blinded committee.

ETHICS AND DISSEMINATION

The protocol and amendments have been approved by the regional ethics review board and French competent authorities (Comité de protection des personnes Ouest I, No.2016-R29). All patients will be included after informed consent according to French law. Results will be disseminated in international scientific journals.

TRIAL REGISTRATION NUMBERS

EudraCT 2016-001054-17 and NCT03149640.

Airway Pseudomonas aeruginosa density in mechanically ventilated patients: clinical impact and relation to therapeutic efficacy of antibiotics

Background

The bacterial density of Pseudomonas aeruginosa is closely related to its pathogenicity. We evaluated the effect of airway P. aeruginosa density on the clinical course of mechanically ventilated patients and the therapeutic efficacy of antibiotics.

Methods

We retrospectively analyzed data of mechanically ventilated ICU patients with P. aeruginosa isolated from endotracheal aspirates. Patients were divided into three groups according to the peak P. aeruginosa density during ICU stay: low (≤ 10⁴ cfu/mL), moderate (10⁵‒10⁶ cfu/mL), and high (≥ 10⁷ cfu/mL) peak density groups. The relationship between peak P. aeruginosa density and weaning from mechanical ventilation, risk factors for isolation of high peak density of P. aeruginosa, and antibiotic efficacy were investigated using multivariate and propensity score-matched analyses.

Results

Four-hundred-and-sixty-one patients were enrolled. Patients with high peak density of P. aeruginosa had higher inflammation and developed more severe respiratory infections. High peak density of P. aeruginosa was independently associated with few ventilator-free days on day 28 (P < 0.01) and increased ICU mortality (P = 0.047). Risk factors for high peak density of P. aeruginosa were prolonged mechanical ventilation (odd ratio [OR] 3.07 95% confidence interval [CI] 1.35‒6.97), non-antipseudomonal cephalosporins (OR 2.17, 95% CI 1.35‒3.49), hyperglycemia (OR 2.01, 95% CI 1.26‒3.22) during ICU stay, and respiratory diseases (OR 1.9, 95% CI 1.12‒3.23). Isolation of commensal colonizer was associated with lower risks of high peak density of P. aeruginosa (OR 0.43, 95% CI 0.26‒0.73). Propensity score-matched analysis revealed that antibiotic therapy for patients with ventilator-associated tracheobronchitis improved weaning from mechanical ventilation only in the high peak P. aeruginosa group.

Conclusions

Patients with high peak density of P. aeruginosa had worse ventilator outcome and ICU mortality. In patients with ventilator-associated tracheobronchitis, antibiotic therapy was associated with favorable ventilator weaning only in the high peak P. aeruginosa density group, and bacterial density could be a good therapeutic indicator for ventilator-associated tracheobronchitis due to P. aeruginosa.

Ventilator-associated tracheobronchitis: an update

Ventilator-associated lower respiratory tract infection is one of the most frequent complications in mechanically ventilated patients. Ventilator-associated tracheobronchitis has been considered a disease that does not warrant antibiotic treatment by the medical community for many years. In the last decade, several studies have shown that tracheobronchitis could be considered an intermediate process that leads to ventilator-associated pneumonia. Furthermore, ventilator-associated tracheobronchitis has a limited impact on overall mortality but shows a significant association with increased patient costs, length of stay, antibiotic use, and duration of mechanical ventilation. Although we still need clear evidence, especially concerning treatment modalities, the present study on ventilator-associated tracheobronchitis highlights that there are important impacts of including this condition in clinical management and epidemiological and infection surveillance.

Update of the treatment of nosocomial pneumonia in the ICU

In accordance with the recommendations of, amongst others, the Surviving Sepsis Campaign and the recently published European treatment guidelines for hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP), in the event of a patient with such infections, empirical antibiotic treatment must be appropriate and administered as early as possible. The aim of this manuscript is to update treatment protocols by reviewing recently published studies on the treatment of nosocomial pneumonia in the critically ill patients that require invasive respiratory support and patients with HAP from hospital wards that require invasive mechanical ventilation. An interdisciplinary group of experts, comprising specialists in anaesthesia and resuscitation and in intensive care medicine, updated the epidemiology and antimicrobial resistance and established clinical management priorities based on patients' risk factors. Implementation of rapid diagnostic microbiological techniques available and the new antibiotics recently added to the therapeutic arsenal has been reviewed and updated. After analysis of the categories outlined, some recommendations were suggested, and an algorithm to update empirical and targeted treatment in critically ill patients has also been designed. These aspects are key to improve VAP outcomes because of the severity of patients and possible acquisition of multidrug-resistant organisms (MDROs).

Ventilator-Associated Tracheobronchitis: To Treat or Not to Treat?

Ventilator-associated tracheobronchitis (VAT) is an infection commonly affecting mechanically ventilated intubated patients. Several studies suggest that VAT is associated with increased duration of mechanical ventilation (MV) and length of intensive care unit (ICU) stay, and a presumptive increase in healthcare costs. Uncertainties remain, however, regarding the cost/benefit balance of VAT treatment. The aim of this narrative review is to discuss the two fundamental and inter-related dilemmas regarding VAT, i.e., (i) how to diagnose VAT? and (ii) should we treat VAT? If yes, should we treat all cases or only selected ones? How should we treat in terms of antibiotic choice, route, treatment duration?

Host-pathogen interaction during mechanical ventilation: systemic or compartmentalized response?

Patients admitted to the intensive care unit (ICU) often require invasive mechanical ventilation. Ventilator-associated lower respiratory tract infections (VA-LRTI), either ventilator-associated tracheobronchitis (VAT) or ventilator-associated pneumonia (VAP), are the most common complication among this patient cohort. VAT and VAP are currently diagnosed and treated as separate entities, viewed as binary disease elements despite an inherent subjectivity in distinguishing them clinically. This paper describes a new approach to pulmonary infections in critically ill patients. Our conjecture is that the host-pathogen interaction during mechanical ventilation determines a local compartmentalized or systemic de-compartmentalized response, based on host immunity and inflammation, and the pathogenic potential of the infecting organism. This compartmentalized or de-compartmentalized response establishes disease severity along a continuum of colonization, VAT or VAP. This change in approach is underpinned by the dissemination hypothesis, which acknowledges the role of immune and inflammatory systems in determining host response to pathogenic organisms in the lower respiratory tract. Those with intact immune and inflammatory pathways may limit infection to a compartmentalized VAT, while immunosuppressed mechanically ventilated patients are at greater risk of a de-compartmentalized VAP. Taking this model from the realm of theory to the bedside will require a greater understanding of inflammatory and immune pathways, and the development of novel disease-specific biomarkers and diagnostic techniques. Advances will lead to early initiation of optimal bespoke antimicrobial therapy, where the intensity and duration of therapy are tailored to clinical, immune and biomarker response. This approach will benefit towards a personalized treatment.

Aerosol Therapy for Pneumonia in the Intensive Care Unit

Antibiotic aerosolization in patients with ventilator-associated pneumonia (VAP) allows very high concentrations of antimicrobial agents in the respiratory secretions, far more than those achievable using the intravenous route. However, data in critically ill patients with pneumonia are limited. Administration of aerosolized antibiotics might increase the likelihood of clinical resolution, but no significant improvements in important outcomes have been consistently documented. Thus, aerosolized antibiotics should be restricted to the treatment of extensively resistant gram-negative pneumonia. In these cases, the use of a vibrating-mesh nebulizer seems to be more efficient, but specific settings and conditions are required to improve lung delivery.

Limiting ventilator-associated complications in ICU intubated subjects: strategies to prevent ventilator-associated events and improve outcomes

Introduction: Intubation is required to maintain the airways in comatose patients and enhance oxygenation in hypoxemic or ventilation in hypercapnic subjects. Recently, the Centers of Disease Control (CDC) created new surveillance definitions designed to identify complications associated with poor outcomes. Areas covered: The new framework proposed by CDC, Ventilator-Associated Events (VAE), has a range of definitions encompassing Ventilator-Associated Conditions (VAC), Infection-related Ventilator-Associated Complications (IVAC), or Possible Ventilator-Associated Pneumonia - suggesting replacing the traditional definitions of Ventilator-Associated Tracheobronchitis (VAT) and Ventilator-Associated Pneumonia (VAP). They focused more on oxygenation variations than on Chest-X rays or inflammatory biomarkers. This article will review the spectrum of infectious (VAP & VAT) complications, as well as the main non-infectious complications, namely pulmonary edema, acute respiratory distress syndrome (ARDS) and atelectasis. Strategies to limit these complications and improve outcomes will be presented. Expert commentary: Improving outcomes should be the objective of implementing bundles of prevention, based on risk factors amenable of intervention. Promotion of measures that reduce the exposition or duration of intubation should be a priority.

Acinetobacter etiology respiratory tract infections associated with mechanical ventilation: what impacts on the prognosis? A retrospective cohort study

INTRODUCTION

Acinetobacter species treatment often represents a challenge. The main objective of this study is identify predictors of ICU mortality in patients submitted to mechanical ventilation (MV).

MATERIALS AND METHODS

Retrospective cohort study. Patients with MV > 48 h who developed a respiratory tract positive culture for Acinetobacter were included, and distinguished among colonized, ventilator-associated pneumonia (VAP) or ventilator-associated tracheobronchitis (VAT) patients. Primary outcome was ICU mortality.

RESULTS

153 patients were in MV and presented positive culture for Acinetobacter calcoaceticus-baumanii complex, 70 of them with VAP, 59 with VAT and 24 patients were colonized. The factors related to ICU mortality were VAP (OR 2.2, 95% CI 1.1-4.5) and shock at the time of diagnosis (OR 4.8, 95% CI 1.8-2.3). In multivariate analysis, only SOFA score at the time of diagnosis (OR 1.06, 95% CI 1.03-1.09) was related with ICU mortality. A paired-matched analysis was performed to assess effect of dual therapy on outcomes, and no effect was found in terms of clinical cure, ICU or hospital mortality or duration of antimicrobial therapy.

CONCLUSIONS

Previous comorbidities and degree of associated organic injury seem to be more important factors in the prognosis than double antibiotic therapy in patients with Acinetobacter-related respiratory infection.

Ventilator-associated events versus ventilator-associated respiratory infections-moving into a new paradigm or merging both concepts, instead?

Despite ventilator-associated respiratory infections (VARI) are reported as the most common and fatal complications related to mechanical ventilation (MV), they are not the unique occurrences. The new classification of ventilator-associated events (VAE) proposed by the centers for disease control and prevention (CDC) enhance the spectra of complications due to MV including both infection-related and non-infectious events. Both VAEs and VARIs are associated with prolonged duration of MV, longer stay in hospital and in the intensive care unit (ICU) and more antibiotic consumption, nonetheless patients with VAEs have worst outcomes. The VARI and VAE algorithms are focused on different targets and the correlation between both classifications is shown to be poor. The diagnostic criteria of the traditional classification have limited accuracy and the non-infectious complications may be misinterpreted as VARI. While the VAE surveillance enhances the spectra of MV complications but excludes less severe VARIs. Noninfective events explain up to 30% of VAEs, the main causes being atelectasis, acute respiratory distress syndrome, pulmonary edema and pulmonary embolism. The bundles assessing VAE are associated with less incidence of VAP and improved outcomes but they fail to reduce the rates of VAE. Automated VAE surveillance is efficient and useful as a quality indicator in the ICU while the differences in the interpretation of VARI criteria limit its role in the design of global protocols and preventive strategies. We suggest that a more comprehensive strategy should combine both algorithms with emphasis on clinical outcomes.

Antibiotic therapy in ventilator-associated tracheobronchitis: a literature review

The concept of ventilator-associated tracheobronchitis is controversial; its definition is not unanimously accepted and often overlaps with ventilator-associated pneumonia. Ventilator-associated tracheobronchitis has an incidence similar to that of ventilator-associated pneumonia, with a high prevalence of isolated multiresistant agents, resulting in an increase in the time of mechanical ventilation and hospitalization but without an impact on mortality. The performance of quantitative cultures may allow better diagnostic definition of tracheobronchitis associated with mechanical ventilation, possibly avoiding the overdiagnosis of this condition. One of the major difficulties in differentiating between ventilator-associated tracheobronchitis and ventilator-associated pneumonia is the exclusion of a pulmonary infiltrate by chest radiography; thoracic computed tomography, thoracic ultrasonography, or invasive specimen collection may also be required. The institution of systemic antibiotic therapy does not improve the clinical impact of ventilator-associated tracheobronchitis, particularly in reducing time of mechanical ventilation, hospitalization or mortality, despite the possible reduced progression to ventilator-associated pneumonia. However, there are doubts regarding the methodology used. Thus, considering the high prevalence of tracheobronchitis associated with mechanical ventilation, routine treatment of this condition would result in high antibiotic usage without clear benefits. However, we suggest the institution of antibiotic therapy in patients with tracheobronchitis associated with mechanical ventilation and septic shock and/or worsening of oxygenation, and other auxiliary diagnostic tests should be simultaneously performed to exclude ventilator-associated pneumonia. This review provides a better understanding of the differentiation between tracheobronchitis associated with mechanical ventilation and pneumonia associated with mechanical ventilation, which can significantly decrease the use of antibiotics in critically ventilated patients.

Intra-Abdominal Hypertension is a Risk Factor for Increased VAP Incidence: A Prospective Cohort Study in the ICU of a Tertiary Hospital

BACKGROUND

Ventilator-associated pneumonia (VAP) might be increased in cases with intra-abdominal hypertension (IAH). However, despite animal experimentation and physiological studies on humans in favor of this hypothesis, there is no definitive clinical data that IAH is associated with VAP. We therefore aimed to study whether IAH is a risk factor for increased incidence of VAP in critical care patients. This 1-center prospective observational cohort study was conducted in the intensive care unit of the University Hospital of Larissa, Greece, during 2013 to 2015. Consecutive patients were recruited if they presented risk factors for IAH at admission and were evaluated systematically for IAH and VAP for a 28-day period.

RESULTS

Forty-five (36.6%) of 123 patients presented IAH and 45 (36.6%) presented VAP; 24 patients presented VAP following IAH. Cox regression analysis showed that VAP was independently associated with IAH (1.06 [1.01-1.11]; P = .053), while there was an indication for an independent association between VAP and abdominal surgery (1.62 [0.87-3.03]; P = .11] and chronic obstructive pulmonary disease (1.79 [0.96-3.37]; P = .06).

CONCLUSIONS

Intra-abdominal hypertension is an independent risk factor for increased VAP incidence in critically ill patients who present risk factors for IAH at admission to the ICU.

Continuous versus intermittent endotracheal cuff pressure control for the prevention of ventilator-associated respiratory infections in Vietnam: study protocol for a randomised controlled trial

BACKGROUND

Ventilator-associated respiratory infection (VARI) comprises ventilator-associated pneumonia (VAP) and ventilator-associated tracheobronchitis (VAT). Although their diagnostic criteria vary, together these are the most common hospital-acquired infections in intensive care units (ICUs) worldwide, responsible for a large proportion of antibiotic use within ICUs. Evidence-based strategies for the prevention of VARI in resource-limited settings are lacking. Preventing the leakage of oropharyngeal secretions into the lung using continuous endotracheal cuff pressure control is a promising strategy. The aim of this study is to investigate the efficacy of automated, continuous endotracheal cuff pressure control in preventing the development of VARI and reducing antibiotic use in ICUs in Vietnam.

METHODS/DESIGN

This is an open-label randomised controlled multicentre trial. We will enrol 600 adult patients intubated for ≤ 24 h at the time of enrolment. Eligible patients will be stratified according to admission diagnosis (180 tetanus, 420 non-tetanus) and site and will be randomised in a 1:1 ratio to receive either (1) automated, continuous control of endotracheal cuff pressure or (2) intermittent measurement and control of endotracheal cuff pressure using a manual cuff pressure meter. The primary outcome is the occurrence of VARI, defined as either VAP or VAT during the ICU admission up to a maximum of 90 days after randomisation. Patients in both groups who are at risk for VARI will receive a standardised battery of investigations if their treating physician feels a new infection has occurred, the results of which will be used by an endpoint review committee, blinded to the allocated arm and independent of patient care, to determine the primary outcome. All enrolled patients will be followed for mortality and endotracheal tube cuff-related complications at 28 days and 90 days after randomisation. Other secondary outcomes include antibiotic use; days ventilated, in ICU and in hospital; inpatient mortality; costs of antibiotics in ICU; duration of ICU stay; and duration of hospital stay.

DISCUSSION

This study will provide high-quality evidence concerning the use of continuous endotracheal cuff pressure control as a method to reduce VARI, antibiotic use and hospitalisation costs and to shorten stay.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT02966392 . Registered on November 9, 2016. Protocol version: 2.0; issue date March 3, 2017.

Impact of immunosuppression on incidence, aetiology and outcome of ventilator-associated lower respiratory tract infections

The aim of this planned analysis of the prospective multinational TAVeM database was to determine the incidence, aetiology and impact on outcome of ventilator-associated lower respiratory tract infections (VA-LRTI) in immunocompromised patients.All patients receiving mechanical ventilation for >48 h were included. Immunocompromised patients (n=663) were compared with non-immunocompromised patients (n=2297).The incidence of VA-LRTI was significantly lower among immunocompromised than among non-immunocompromised patients (16.6% versus 24.2%; sub-hazard ratio 0.65, 95% CI 0.53-0.80; p<0.0001). Similar results were found regarding ventilator-associated tracheobronchitis (7.3% versus 11.6%; sub-hazard ratio 0.61, 95% CI 0.45-0.84; p=0.002) and ventilator-associated pneumonia (9.3% versus 12.7%; sub-hazard ratio 0.72, 95% CI 0.54-0.95; p=0.019). Among patients with VA-LRTI, the rates of multidrug-resistant bacteria (72% versus 59%; p=0.011) and intensive care unit mortality were significantly higher among immunocompromised than among non-immunocompromised patients (54% versus 30%; OR 2.68, 95% CI 1.78-4.02; p<0.0001). In patients with ventilator-associated pneumonia, mortality rates were higher among immunocompromised than among non-immunocompromised patients (64% versus 34%; p<0.001).Incidence of VA-LRTI was significantly lower among immunocompromised patients, but it was associated with a significantly higher mortality rate. Multidrug-resistant pathogens were more frequently found in immunocompromised patients with VA-LRTI.

Antimicrobial Stewardship Opportunities in Critically Ill Patients with Gram-Negative Lower Respiratory Tract Infections: A Multicenter Cross-Sectional Analysis

INTRODUCTION

Lower respiratory tract infections (LRTIs) are a major cause of morbidity and death. Because of changes in how LRTIs are defined coupled with the increasing prevalence of drug resistance, there is a gap in knowledge regarding the current burden of antimicrobial use for Centers for Disease Control and Prevention (CDC)-defined LRTIs. We describe the infection characteristics, antibiotic consumption, and clinical and economic outcomes of patients with Gram-negative (GN) LRTIs treated in intensive care units (ICUs).

METHODS

This was a retrospective, observational, cross-sectional study of adult patients treated in ICUs at two large academic medical centers in metropolitan Detroit, Michigan, from October 2013 to October 2015. To meet the inclusion criteria, patients must have had CDC-defined LRTI caused by a GN pathogen during ICU stay. Microbiological assessment of available Pseudomonas aeruginosa isolates included minimum inhibitory concentrations for key antimicrobial agents.

RESULTS

Four hundred and seventy-two patients, primarily from the community (346, 73.3%), were treated in medical ICUs (272, 57.6%). Clinically defined pneumonia was common (264, 55.9%). Six hundred and nineteen GN organisms were identified from index respiratory cultures: P. aeruginosa was common (224, 36.2%), with 21.6% of these isolates being multidrug resistant. Cefepime (213, 45.1%) and piperacillin/tazobactam (174, 36.8%) were the most frequent empiric GN therapies. Empiric GN therapy was inappropriate in 44.6% of cases. Lack of in vitro susceptibility (80.1%) was the most common reason for inappropriateness. Patients with inappropriate empiric GN therapy had longer overall stay, which translated to a median total cost of care of $79,800 (interquartile range $48,775 to $129,600) versus $68,000 (interquartile range $38,400 to $116,175), p = 0.013. Clinical failure (31.5% vs 30.0%, p = 0.912) and in-hospital all-cause mortality (26.4% vs 25.9%, p = 0.814) were not different.

CONCLUSION

Drug-resistant pathogens were frequently found and empiric GN therapy was inappropriate in nearly 50% of cases. Inappropriate therapy led to increased lengths of stay and was associated with higher costs of care.

A case-control study on the clinical impact of ventilator associated tracheobronchitis in adult patients who did not develop ventilator associated pneumonia

OBJECTIVES

The main objective was to determine whether ventilator-associated tracheobronchitis (VAT) is related to increased length of ICU stay. Secondary endpoints included prolongation of hospital stay, as well as, ICU and hospital mortality.

DESIGN

A retrospective matched case-control study. Each case was matched with a control for duration of ventilation (± 2 days until development of ventilator-associated tracheobronchitis), disease severity (Acute Physiology and Chronic Health Evaluation II) at admission ± 3, diagnostic category and age ±10 years.

PATIENTS

Critically ill adults admitted to a polyvalent 30-beds ICU with the diagnosis of VAT in the period 2013-2016.

MAIN RESULTS

We identified 76 cases of VAT admitted to our ICU during the study period. No adequate controls were found for 3 patients with VAT. There were no significant differences in demographic characteristics, reasons for admission and comorbidities. Patients with VAT had a longer ICU length of stay, median 22 days (14-35), compared to controls, median 15 days (8-27), p=.02. Ventilator days were also significantly increased in VAT patients, median 18 (9-28) versus 9 days (5-16), p=.03. There was no significant difference in total hospital length of stay 40 (28-61) vs. 35days (23-54), p=.32; ICU mortality (20.5 vs. 31.5% p=.13) and hospital mortality (30.1 vs. 43.8% p=.09). We performed a subanalysis of patients with microbiologically proven VAT receiving adequate antimicrobial treatment and did not observe significant differences between cases and the corresponding controls.

CONCLUSIONS

VAT is associated with increased length of intensive care unit stay and longer duration of mechanical ventilation. This effect disappears when patients receive appropriate empirical treatment.

Clinical Features and Antimicrobial Resistance of Bacterial Agents of Ventilator-Associated Tracheobronchitis in Hamedan, Iran

OBJECTIVES

Ventilator-associated tracheobronchitis (VAT) is a common cause of mortality and morbidity in patients admitted to intensive care units (ICUs). This study was conducted to evaluate the clinical course, etiology, and antimicrobial resistance of bacterial agents of VAT in ICUs in Hamedan, Iran.

METHODS

During a 12-month period, all patients with VAT in a medical and a surgical ICU were included. The criteria for the diagnosis of VAT were fever, mucus production, a positive culture of tracheal secretions, and the absence of lung infiltration. Clinical course, including changes in temperature and tracheal secretions, and outcomes were followed. The endotracheal aspirates were cultured on blood agar and chocolate agar, and antimicrobial susceptibility testing of isolates were performed using the disk diffusion method.

RESULTS

Of the 1 070 ICU patients, 69 (6.4%) were diagnosed with VAT. The mean interval between the patient's intubation and the onset of symptoms was 4.7±8.5 days. The mean duration of response to treatment was 4.9±4.7 days. A total of 23 patients (33.3%) progressed to ventilator-associated pneumonia (VAP), and 38 patients (55.0%) died. The most prevalent bacterial isolates included Acinetobacter baumannii (24.6%), Pseudomonas aeruginosa (20.2%), and Enterobacter (13.0%). P. aeruginosa and Enterobacter were the most prevalent bacteria in surgical ICU, and A. baumannii and K. pneumoniae were the most common in the medical ICU. All A. baumannii and Citrobacter species were multidrug-resistant (MDR). MDR pathogens were more prevalent in medical ICU compared to surgical ICU (p < 0.001).

CONCLUSIONS

VAT increases the rates of progression to VAP, the need for tracheostomy, and the incidence of mortality in ICUs. Most bacterial agents of VAT are MDR. Preventive policies for VAP, including the use of ventilator care bundle, and appropriate empirical antibiotic therapy for VAT may reduce the incidence of VAP.

Respiratory research networks in Europe and beyond: aims, achievements and aspirations for the 21st century

Healthcare-associated infection, such as intensive care unit (ICU)-related respiratory infections, remain the most frequently encountered morbidity of ICU admission, prolonging hospital stay and increasing mortality rates. The epidemiology of ICU-related respiratory infections, particularly nonventilated ICU-associated pneumonia and ventilator-associated tracheobronchitis, appears to be quite different among different countries. European countries have different prevalence, patterns and mechanism of resistance, as well as different treatments chosen by different attending physicians. The classical clinical research process in respiratory infections consists of the following loop: 1) identification of knowledge gaps; 2) systematic review and search for adequate answers; 3) generation of study hypotheses; 4) design of study protocols; 5) collection clinical data; 6) analysis and interpretation of the results; and 7) implementation of the results in clinical practice.

Pseudomonas aeruginosa proteolytically alters the interleukin 22-dependent lung mucosal defense

The IL-22 signaling pathway is critical for regulating mucosal defense and limiting bacterial dissemination. IL-22 is unusual among interleukins because it does not directly regulate the function of conventional immune cells, but instead targets cells at outer body barriers, such as respiratory epithelial cells. Consequently, IL-22 signaling participates in the maintenance of the lung mucosal barrier by controlling cell proliferation and tissue repair, and enhancing the production of specific chemokines and anti-microbial peptides. Pseudomonas aeruginosa is a major pathogen of ventilator-associated pneumonia and causes considerable lung tissue damage. A feature underlying the pathogenicity of this bacterium is its capacity to persist and develop in the host, particularly in the clinical context of nosocomial lung infections. We aimed to investigate the ability of P. auruginosa to disrupt immune-epithelial cells cross-talk. We found that P. aeruginosa escapes the host mucosal defenses by degrading IL-22, leading to severe inhibition of IL-22-mediated immune responses. We demonstrated in vitro that, protease IV, a type 2 secretion system-dependent serine protease, is responsible for the degradation of IL-22 by P. aeruginosa. Moreover, the major anti-proteases molecules present in the lungs were unable to inhibit protease IV enzymatic activity. In addition, tracheal aspirates of patients infected by P. aeruginosa contain protease IV activity which further results in IL-22 degradation. This so far undescribed cleavage of IL-22 by a bacterial protease is likely to be an immune-evasion strategy that contributes to P. aeruginosa-triggered respiratory infections.

Nebulized antibiotics in mechanically ventilated patients: a challenge for translational research from technology to clinical care

Nebulized antibiotic therapy directly targets airways and lung parenchyma resulting in high local concentrations and potentially lower systemic toxicities. Experimental and clinical studies have provided evidence for elevated lung concentrations and rapid bacterial killing following the administration of nebulized antibiotics during mechanical ventilation. Delivery of high concentrations of antibiotics to infected lung regions is the key to achieving efficient nebulized antibiotic therapy. However, current non-standardized clinical practice, the difficulties with implementing optimal nebulization techniques and the lack of robust clinical data have limited its widespread adoption. The present review summarizes the techniques and clinical constraints for optimal delivery of nebulized antibiotics to lung parenchyma during invasive mechanical ventilation. Pulmonary pharmacokinetics and pharmacodynamics of nebulized antibiotic therapy to treat ventilator-associated pneumonia are discussed and put into perspective. Experimental and clinical pharmacokinetics and pharmacodynamics support the use of nebulized antibiotics. However, its clinical benefits compared to intravenous therapy remain to be proved. Future investigations should focus on continuous improvement of nebulization practices and techniques. Before expanding its clinical use, careful design of large phase III randomized trials implementing adequate therapeutic strategies in targeted populations is required to demonstrate the clinical effectiveness of nebulized antibiotics in terms of patient outcomes and reduction in the emergence of antibiotic resistance.

Systemic antibiotics for preventing ventilator-associated pneumonia in comatose patients: a systematic review and meta-analysis

BACKGROUND

Early-onset ventilator-associated pneumonia (EO-VAP) is the leading cause of morbidity and mortality in comatose patients. However, VAP prevention bundles focus mainly on late-onset VAP and may be less effective in preventing EO-VAP in comatose patients. Systemic antibiotic administration at the time of intubation may have a role in preventing EO-VAP. Therefore, we evaluated the effectiveness of systemic antibiotic administration in VAP prevention in comatose patients through a systematic review and meta-analysis.

METHODS

We searched for studies published through December 2015 that evaluated systemic antibiotic prophylaxis in comatose patients. Two authors independently selected and evaluated full-length reports of randomized clinical trials or prospective cohorts in patients aged >16 years that evaluated the impact of systemic antibiotics at the time of intubation on EO-VAP compared to placebo or no prophylaxis. The outcome variables were the incidence of EO-VAP, the duration of mechanical ventilation, ICU length of stay, and ICU mortality.

RESULTS

We identified 10,988 citations, yielding 26 articles for further analysis; three studies with 267 patients were finally analyzed. Most patients (n = 135) were comatose due to head trauma. Systemic antibiotic administration was associated with decreased incidence of EO-VAP (RR 0.32; 95% CI 0.19-0.54) and shorter ICU LOS (standardized mean difference -0.32; 95% CI -0.56 to -0.08), but had no effect on mortality (RR 1.03; 95% CI 0.7-1.53) or duration of mechanical ventilation (standardized mean difference -0.16; 95% CI -0.41 to 0.08).

CONCLUSIONS

Antibiotic prophylaxis in comatose patients reduced the incidence of EO-VAP and decreased the ICU stay slightly. Future trials are needed to confirm these results.

Ventilator-Associated Pneumonia: The Role of Emerging Diagnostic Technologies

Antibiotic resistance has emerged as a key determinant of outcome in patients with serious infections along with the virulence of the underlying pathogen. Within the intensive care unit (ICU) setting, ventilator-associated pneumonia (VAP) is a common nosocomial infection that is frequently caused by multidrug-resistant bacteria. Antimicrobial resistance is a growing challenge in the care of critically ill patients. Escalating rates of antibiotic resistance add substantially to the morbidity, mortality, and cost related to infection in the ICU. Both gram-positive organisms, such as methicillin-resistant Staphylococcus aureus and vancomycin-intermediate S. aureus, and gram-negative bacteria, including Pseudomonas aeruginosa, Acinetobacter species, carbapenem-resistant Enterobacteriaceae, such as the Klebsiella pneumoniae carbapenemase-producing bacteria, and extended spectrum β-lactamase organisms, have contributed to the escalating rates of resistance seen in VAP and other nosocomial infections. The rising rates of antimicrobial resistance have led to the routine empiric administration of broad-spectrum antibiotics even when bacterial infection is not documented. Moreover, there are several new broader-spectrum antibiotics that have recently become available and others scheduled for approval in the near future. The challenge to ICU clinicians is how to most effectively utilize these agents to maximize patient benefits while minimizing further emergence of resistance. Use of rapid diagnostics may hold the key for achieving this important balance. There is an urgent need for integrating the administration of new and existing antibiotics with the emerging rapid diagnostic technologies in a way that is both cost-effective and sustainable for the long run.

Individualized antibiotic therapy in patients with ventilator-associated pneumonia

The optimal duration of the treatment of ventilator-associated pneumonia (VAP) is still the subject of debate. While 1 week treatment has been reported as possibly sufficient, patients generally receive antibiotic therapy for 10 to 14 days. The purpose of our study was to investigate whether length of treatment in patients with VAP can be reduced with an individualized therapeutic strategy. The study was performed prospectively with patients diagnosed with VAP in our hospital's intensive care units between 1 January and 31 December 2015. Duration of antibiotic therapy was determined with 5 day clinical evaluation according to previously established criteria. Patients were divided into two groups depending on length of treatment, short (7-10 days) and long treatment (>10 days). Nineteen patients received 7 to 10 day antibiotic therapy, and 30 received >10 day antibiotic therapy. Demographic and clinical characteristics, Glasgow Coma Scale score, CPIS and the PaO2/FiO2 ratio at the time of diagnosis of VAP were statistically similar between the two groups (P>0.05). A second VAP attack occurred post-treatment in three patients receiving short-term treatment and in four receiving long-term treatment (P=0.561). The numbers of antibiotic-free days were 15.6±6.2 in the short-term treatment group and 8.3±7.5 in the long-term group (P<0.0001). One of the patients receiving short-term treatment died within 28 days after treatment, and four of the patients receiving long-term treatment (P=0.348) did so. The most commonly observed micro-organisms in both groups were Acinetobacterbaumannii and Pseudomonasaeruginosa. Short-term treatment can be administered in cases with early clinical and laboratory response started on VAP treatment by considering individual characteristics and monitoring fever, CPIS, the PaO2/FiO2 ratio, C-reactive protein and procalcitonin values.

Pre-emptive antibiotic therapy to reduce ventilator-associated pneumonia: "thinking outside the box"

Mechanically ventilated, intubated patients are at increased risk for tracheal colonization with bacterial pathogens that may progress to heavy bacterial colonization, ventilator-associated tracheobronchitis (VAT), and/or ventilator-associated pneumonia (VAP). Previous studies report that 10 to 30 % of patients with VAT progress to VAP, resulting in increased morbidity and significant acute and chronic healthcare costs. Several natural history studies, randomized, controlled trials, and a meta-analysis have reported antibiotic treatment for VAT can reduce VAP, ventilator days, length of intensive care unit (ICU) stay, and patient morbidity and mortality. We discuss early diagnostic criteria, etiologic agents, and benefits of initiating, early, appropriate intravenous or aerosolized antibiotic(s) to treat VAT and reduce VAP, to improve patient outcomes by reducing lung damage, length of ICU stay, and healthcare costs.

Management of Adults With Hospital-acquired and Ventilator-associated Pneumonia: 2016 Clinical Practice Guidelines by the Infectious Diseases Society of America and the American Thoracic Society

It is important to realize that guidelines cannot always account for individual variation among patients. They are not intended to supplant physician judgment with respect to particular patients or special clinical situations. IDSA considers adherence to these guidelines to be voluntary, with the ultimate determination regarding their application to be made by the physician in the light of each patient's individual circumstances.These guidelines are intended for use by healthcare professionals who care for patients at risk for hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP), including specialists in infectious diseases, pulmonary diseases, critical care, and surgeons, anesthesiologists, hospitalists, and any clinicians and healthcare providers caring for hospitalized patients with nosocomial pneumonia. The panel's recommendations for the diagnosis and treatment of HAP and VAP are based upon evidence derived from topic-specific systematic literature reviews.

Is HELICS the Right Way? Lack of Chest Radiography Limits Ventilator-Associated Pneumonia Surveillance in Wales

Introduction: The reported incidence of ventilator-associated pneumonia (VAP) in Wales is low compared with surveillance data from other European regions. It is unclear whether this reflects success of the Welsh healthcare-associated infection prevention measures or limitations in the application of European VAP surveillance methods. Our primary aim was to investigate episodes of ventilator-associated respiratory tract infection (VARTI), to identify episodes that met established criteria for VAP, and to explore reasons why others did not, according to the Hospitals in Europe Link for Infection Control through Surveillance (HELICS) definitions.

Materials and Methods: During two 14-day study periods 2012–2014, investigators reviewed all invasively ventilated patients in all 14 Welsh Intensive Care Units (ICUs). Episodes were identified in which the clinical team had commenced antibiotic therapy because of suspected VARTI. Probability of pneumonia was estimated using a modified Clinical Pulmonary Infection Score (mCPIS). Episodes meeting HELICS definitions of VAP were identified, and reasons for other episodes not meeting definitions examined. In the second period, each patient was also assessed with regards to the development of a ventilator-associated event (VAE), according to recent US definitions.

Results: The study included 306 invasively ventilated patients; 282 were admitted to ICU for 48 h or more. 32 (11.3%) patients were commenced on antibiotics for suspected VARTI. Ten of these episodes met HELICS definitions of VAP, an incidence of 4.2 per 1000 intubation days. In 48% VARTI episodes, concurrent chest radiography was not performed, precluding the diagnosis of VAP. Mechanical ventilation (16.0 vs. 8.0 days; p = 0.01) and ICU stay (25.0 vs. 11.0 days; p = 0.01) were significantly longer in patients treated for VARTI compared to those not treated. There was no overlap between episodes of VARTI and of VAE.

Discussion: HELICS VAP surveillance definitions identified less than one-third of cases in which antibiotics were commenced for suspected ventilator-associated RTI. Lack of chest radiography precluded nearly 50% cases from meeting the surveillance definition of VAP, and as a consequence we are almost certainly underestimating the incidence of VAP in Wales.

Looking Beyond Respiratory Cultures: Microbiome-Cytokine Signatures of Bacterial Pneumonia and Tracheobronchitis in Lung Transplant Recipients

Bacterial pneumonia and tracheobronchitis are diagnosed frequently following lung transplantation. The diseases share clinical signs of inflammation and are often difficult to differentiate based on culture results. Microbiome and host immune-response signatures that distinguish between pneumonia and tracheobronchitis are undefined. Using a retrospective study design, we selected 49 bronchoalveolar lavage fluid samples from 16 lung transplant recipients associated with pneumonia (n = 8), tracheobronchitis (n = 12) or colonization without respiratory infection (n = 29). We ensured an even distribution of Pseudomonas aeruginosa or Staphylococcus aureus culture-positive samples across the groups. Bayesian regression analysis identified non-culture-based signatures comprising 16S ribosomal RNA microbiome profiles, cytokine levels and clinical variables that characterized the three diagnoses. Relative to samples associated with colonization, those from pneumonia had significantly lower microbial diversity, decreased levels of several bacterial genera and prominent multifunctional cytokine responses. In contrast, tracheobronchitis was characterized by high microbial diversity and multifunctional cytokine responses that differed from those of pneumonia-colonization comparisons. The dissimilar microbiomes and cytokine responses underlying bacterial pneumonia and tracheobronchitis following lung transplantation suggest that the diseases result from different pathogenic processes. Microbiomes and cytokine responses had complementary features, suggesting that they are closely interconnected in the pathogenesis of both diseases.

Advances in antibiotic therapy in the critically ill

Infections occur frequently in critically ill patients and their management can be challenging for various reasons, including delayed diagnosis, difficulties identifying causative microorganisms, and the high prevalence of antibiotic-resistant strains. In this review, we briefly discuss the importance of early infection diagnosis, before considering in more detail some of the key issues related to antibiotic management in these patients, including controversies surrounding use of combination or monotherapy, duration of therapy, and de-escalation. Antibiotic pharmacodynamics and pharmacokinetics, notably volumes of distribution and clearance, can be altered by critical illness and can influence dosing regimens. Dosing decisions in different subgroups of patients, e.g., the obese, are also covered. We also briefly consider ventilator-associated pneumonia and the role of inhaled antibiotics. Finally, we mention antibiotics that are currently being developed and show promise for the future.

Incidence and prognosis of ventilator-associated tracheobronchitis (TAVeM): a multicentre, prospective, observational study

BACKGROUND

Ventilator-associated tracheobronchitis has been suggested as an intermediate process between tracheobronchial colonisation and ventilator-associated pneumonia in patients receiving mechanical ventilation. We aimed to establish the incidence and effect of ventilator-associated tracheobronchitis in a large, international patient cohort.

METHODS

We did a multicentre, prospective, observational study in 114 intensive care units (ICU) in Spain, France, Portugal, Brazil, Argentina, Ecuador, Bolivia, and Colombia over a preplanned time of 10 months. All patients older than 18 years admitted to an ICU who received invasive mechanical ventilation for more than 48 h were eligible. We prospectively obtained data for incidence of ventilator-associated lower respiratory tract infections, defined as ventilator-associated tracheobronchitis or ventilator-associated pneumonia. We grouped patients according to the presence or absence of such infections, and obtained data for the effect of appropriate antibiotics on progression of tracheobronchitis to pneumonia. Patients were followed up until death or discharge from hospital. To account for centre effects with a binary outcome, we fitted a generalised estimating equation model with a logit link, exchangeable correlation structure, and non-robust standard errors. This trial is registered with ClinicalTrials.gov, number NCT01791530.

FINDINGS

Between Sept 1, 2013, and July 31, 2014, we obtained data for 2960 eligible patients, of whom 689 (23%) developed ventilator-associated lower respiratory tract infections. The incidence of ventilator-associated tracheobronchitis and that of ventilator-associated pneumonia at baseline were similar (320 [11%; 10·2 of 1000 mechanically ventilated days] vs 369 [12%; 8·8 of 1000 mechanically ventilated days], p=0·48). Of the 320 patients with tracheobronchitis, 250 received appropriate antibiotic treatment and 70 received inappropriate antibiotics. 39 patients with tracheobronchitis progressed to pneumonia; however, the use of appropriate antibiotic therapy for tracheobronchitis was associated with significantly lower progression to pneumonia than was inappropriate treatment (19 [8%] of 250 vs 20 [29%] of 70, p<0·0001; crude odds ratio 0·21 [95% CI 0·11-0·41]). Significantly more patients with ventilator-associated pneumonia died (146 [40%] of 369) than those with tracheobronchitis (93 [29%] of 320) or absence of ventilator-associated lower respiratory tract infections (673 [30%] of 2271, p<0·0001). Median time to discharge from the ICU for survivors was significantly longer in the tracheobronchitis (21 days [IQR 15-34]) and pneumonia (22 [13-36]) groups than in the group with no ventilator-associated lower respiratory tract infections (12 [8-20]; hazard ratio 1·65 [95% CI 1·38-1·97], p<0·0001).

INTERPRETATION

This large database study emphasises that ventilator-associated tracheobronchitis is a major health problem worldwide, associated with high resources consumption in all countries. Our findings also show improved outcomes with use of appropriate antibiotic treatment for both ventilator-associated tracheobronchitis and ventilator-associated pneumonia, underlining the importance of treating both infections, since inappropriate treatment of tracheobronchitis was associated with a higher risk of progression to pneumonia.

FUNDING

None.

Antibiotic therapy for ventilator-associated tracheobronchitis: a standard of care to reduce pneumonia, morbidity and costs?

PURPOSE OF REVIEW

The present review draws our attention to ventilator-associated tracheobronchitis (VAT) as a distinct clinical entity that has been associated with progression to ventilator-associated pneumonia (VAP) and worse patient outcomes. In contrast to VAP, which has been extensively investigated for over the past 30 years, most VAT studies have been conducted in the past decade. There are ample data which demonstrate that VAT may progress to VAP, have more ventilator days, and have longer ICU stay that may translate into higher healthcare costs.

RECENT FINDINGS

The article focuses on the diagnostic criteria for VAT, causative agents, and studies analyzing associations between VAT and patient outcomes in relation to early, appropriate intravenous, and/or aerosolized antibiotic therapy. Aerosolized antibiotic treatment delivered by improved device technology is a novel approach that has proved to be effective for the treatment and eradication of multidrug-resistant bacterial pathogens. Aerosolized antibiotics are effective in decreasing the use of systemic antibiotics, reducing bacterial resistance, and may also facilitate clinical resolution of infection.

SUMMARY

Evidence presented in this review supports treatment of VAT with early and appropriate antibiotic therapy as a standard of care to reduce VAP, ventilator days, and duration of ICU stay in high-risk patient population.

Ventilator-associated tracheobronchitis: pre-emptive, appropriate antibiotic therapy recommended

Nseir and colleagues presented data from a large multicenter study of patients with ventilator-associated tracheobronchitis (VAT), demonstrating that appropriate antibiotic therapy for VAT was an independent predictor for reducing transition to pneumonia (ventilator-associated pneumonia, or VAP). These data added to the growing evidence supporting the use of appropriate antibiotic therapy for VAT as a standard of care to prevent VAP and improve patient outcomes.