Comparison of bronchoalveolar lavage and mini-bronchoalveolar lavage in the diagnosis of pneumonia in immunocompromised patients

Predictive values of methicillin-resistant Staphylococcus aureus nasal swabs for pneumonia in burn ICU patients

INTRODUCTION/OBJECTIVE

This retrospective cohort study aimed to determine the sensitivity, specificity, and positive (PPV) and negative predictive values (NPV) of MRSA nasal swabs for pneumonia in burn-injured intensive care unit (ICU) patients.

METHODS

Patients 18 years or older admitted to the Burn ICU at a tertiary medical center from 2016 to 2021 were included if they had any burns, a pneumonia ICD-10 code, an MRSA nasal swab obtained during admission, and any respiratory cultures associated with at least five consecutive days of antibiotics.

RESULTS

There were 267 occurrences of pneumonia across 136 patients. MRSA nasal swabs had an overall sensitivity of 39 %, specificity of 98.7 %, PPV of 84.2 %, and NPV of 89.9 %. MRSA nasal swabs obtained less than seven days from antibiotic initiation had a specificity of 98.6 % and NPV of 98.6 %; meanwhile, swabs obtained at least seven days from antibiotic initiation had a specificity of 98.7 % and NPV of 86.4 %.

CONCLUSIONS

The high specificity and NPV indicate that negative MRSA nasal swabs obtained less than seven days from antibiotic initiation may be used to de-escalate anti-MRSA antibiotics in clinically stable burn-injured patients with suspicion of pneumonia. The decrease in NPV suggests that it may be beneficial to obtain a repeat swab periodically.

The agreement between bronchoalveolar lavage, bronchial wash and sputum culture: a retrospective study

PURPOSE

Bronchoalveolar lavage is commonly used in clinical practice for unresolved pneumonia. However, bronchoalveolar lavage is not suitable for all patients as it is an invasive procedure and can worsen oxygenation. The diagnostic value of bronchial wash and sputum has been debated extensively over the years. In this study, we aim to compare the diagnostic value in several pathogens of bronchoalveolar lavage and bronchial wash, and secondarily bronchoalveolar lavage and sputum.

METHODS

We retrospectively included all adult patients in our hospital who underwent bronchoalveolar lavage, bronchial wash, and where sputum sampling was done between January 1st of 2018 and December 31st of 2021. The intraclass correlation coefficient was computed for the three tests.

RESULTS

In total, 308 patients were included. We found a level of correlation of 0.819 and 0.865, respectively, between bronchoalveolar lavage and bronchial wash for two pathogens: Staphylococcus aureus and Pseudomonas aeruginosa. For Stenotrophomonas maltophilia and Aspergillus fumigatus, we found an intraclass correlation coefficient of 0.568 and 0.624, respectively. Between bronchoalveolar lavage and sputum, we found varying levels of agreement.

CONCLUSION

Our study shows reasonably well agreement levels between bronchoalveolar lavage and bronchial wash, suggesting that bronchial wash could potentially be an alternative to bronchoalveolar lavage.

Comparing the Accuracy of Mini-BAL to Bronchoscopic BAL in the Diagnosis of Pneumonia Among Ventilated Patients: A Systematic Literature Review

Background: Despite its widespread use, there are no direct studies comparing mini-bronchoalveolar lavage (mini-BAL) to bronchoscopic bronchoalveolar lavage (BAL) for diagnosing pneumonia in ventilated patients. The aim of this study was to perform a systematic review of studies comparing ventilated patients undergoing both bronchoscopic BAL and mini-BAL, to determine the mini-BAL's diagnostic accuracy. Methods: We conducted a systematic review searching the databases PubMed (MEDLINE), EMBASE, Cochrane Library, Scopus, and clinicaltrials.gov from inception until January 2022, in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Search terms included variations on "pneumonia," "critical illness," and "mini-bronchoalveolar lavage." Article screening and data extraction were performed independently by 2 reviewers. Results: Our search yielded 4296 abstracts. This was narrowed to 6 studies in which each patient underwent both mini-BAL and bronchoscopic BAL in succession. Included patients had a mean APACHE II score of 20.02 ± 3.81 and 15.95 ± 11.46 ventilator days. The sensitivity of the mini-BAL for diagnosis of pneumonia was 0.90 (95% confidence interval [CI]: 0.778-1.000) and the specificity was 0.827 (95% CI: 0.716-0.938). Limitations included inconsistency in volume of saline instilled and heterogeneity in included patients Conclusion: This study is the first to compile data from multiple publications directly comparing the mini-BAL to bronchoscopic BAL for diagnosing pneumonia in ventilated patients. Our data demonstrate a high degree of both sensitivity and specificity of mini-BAL for the diagnosis of pneumonia in ventilated patients and indicate that mini-BAL could be considered as an acceptable alternative diagnostic study.

Bronchial aspirate obtained during bronchoscopy yields increased fungal load compared to bronchoalveolar lavage fluid in patients at risk of invasive aspergillosis and Pneumocystis pneumonia

Bronchoalveolar lavage fluid (BALF) is a standard respiratory sample for diagnosing invasive fungal diseases like Pneumocystis pneumonia (PCP) and invasive pulmonary aspergillosis (IPA). However, procedural variations exist across medical centers and wards. This study aimed to compare the diagnostic potential of BALF and bronchial aspirate (BA) obtained during bronchoscopy in 173 patients suspected of fungal infections. A prospective observational study was conducted from April 2020 to November 2021. BALF and BA were collected during bronchoscopy and subjected to direct examination, fungal culture, Aspergillus fumigatus qPCR (AfqPCR), and Pneumocystis jirovecii qPCR (PjqPCR). Galactomannan detection was performed on BALF. Patients were classified based on established European Organization for Research and Treatment of Cancer (EORTC) criteria. Out of 173 patients, 75 tested positive for at least one test in BA or BALF. For Aspergillus, proportion of positive AfqPCR (14.5% vs. 9.2%; P < 0.0001) and fungal loads (Cq of 31.3 vs. 32.8; P = 0.0018) were significantly higher in BA compared to BALF. For Pneumocystis, fungal loads by PjqPCR was also higher in BA compared to BALF (Cq of 34.2 vs. 35.7; P = 0.003). BA only detected A. fumigatus and P. jirovecii in 12 (42.9%) and 8 (19.5%) patients, respectively. BA obtained during a BAL procedure can be a suitable sample type for increased detection of P. jirovecii and A. fumigatus by qPCR. The use of BA in diagnostic algorithms requires further investigation in prospective studies.

Nonbronchoscopic Bronchoalveolar Lavage Improves Respiratory Culture Accuracy in Critically Ill Patients

OBJECTIVES

Diagnosis of pneumonia is challenging in critically ill, intubated patients due to limited diagnostic modalities. Endotracheal aspirate (EA) cultures are standard of care in many ICUs; however, frequent EA contamination leads to unnecessary antibiotic use. Nonbronchoscopic bronchoalveolar lavage (NBBL) obtains sterile, alveolar cultures, avoiding contamination. However, paired NBBL and EA sampling in the setting of a lack of gold standard for airway culture is a novel approach to improve culture accuracy and limit antibiotic use in the critically ill patients.

DESIGN

We designed a pilot study to test respiratory culture accuracy between EA and NBBL. Adult, intubated patients with suspected pneumonia received concurrent EA and NBBL cultures by registered respiratory therapists. Respiratory culture microbiology, cell counts, and antibiotic prescribing practices were examined.

SETTING

We performed a prospective pilot study at the Cleveland Clinic Main Campus Medical ICU in Cleveland, Ohio for 22 months from May 2021 through March 2023.

PATIENTS OR SUBJECTS

Three hundred forty mechanically ventilated patients with suspected pneumonia were screened. Two hundred fifty-seven patients were excluded for severe hypoxia (Fio2 ≥ 80% or positive end-expiratory pressure ≥ 12 cm H2O), coagulopathy, platelets less than 50,000, hemodynamic instability as determined by the treating team, and COVID-19 infection to prevent aerosolization of the virus.

INTERVENTIONS

All 83 eligible patients were enrolled and underwent concurrent EA and NBBL.

MEASUREMENTS AND MAIN RESULTS

More EA cultures (42.17%) were positive than concurrent NBBL cultures (26.51%, p = 0.049), indicating EA contamination. The odds of EA contamination increased by eight-fold 24 hours after intubation. EA was also more likely to be contaminated with oral flora when compared with NBBL cultures. There was a trend toward decreased antibiotic use in patients with positive EA cultures if paired with a negative NBBL culture. Alveolar immune cell populations were recovered from NBBL samples, indicating successful alveolar sampling. There were no major complications from NBBL.

CONCLUSIONS

NBBL is more accurate than EA for respiratory cultures in critically ill, intubated patients. NBBL provides a safe and effective technique to sample the alveolar space for both clinical and research purposes.

Respiratory metagenomics: route to routine service

PURPOSE OF REVIEW

The coronavirus disease 2019 pandemic demonstrated broad utility of pathogen sequencing with rapid methodological progress alongside global distribution of sequencing infrastructure. This review considers implications for now moving clinical metagenomics into routine service, with respiratory metagenomics as the exemplar use-case.

RECENT FINDINGS

Respiratory metagenomic workflows have completed proof-of-concept, providing organism identification and many genotypic antimicrobial resistance determinants from clinical samples in <6 h. This enables rapid escalation or de-escalation of empiric therapy for patient benefit and reducing selection of antimicrobial resistance, with genomic-typing available in the same time-frame. Attention is now focussed on demonstrating clinical, health-economic, accreditation, and regulatory requirements. More fundamentally, pathogen sequencing challenges the traditional culture-orientated time frame of microbiology laboratories, which through automation and centralisation risks becoming increasingly separated from the clinical setting. It presents an alternative future where infection experts are brought together around a single genetic output in an acute timeframe, aligning the microbiology target operating model with the wider human genomic and digital strategy.

SUMMARY

Pathogen sequencing is a transformational proposition for microbiology laboratories and their infectious diseases, infection control, and public health partners. Healthcare systems that link output from routine clinical metagenomic sequencing, with pandemic and antimicrobial resistance surveillance, will create valuable tools for protecting their population against future infectious diseases threats.

Composition and diversity analysis of the lung microbiome in patients with suspected ventilator-associated pneumonia

Background

Ventilator-associated pneumonia (VAP) is associated with high morbidity and health care costs, yet diagnosis remains a challenge. Analysis of airway microbiota by amplicon sequencing provides a possible solution, as pneumonia is characterised by a disruption of the microbiome. However, studies evaluating the diagnostic capabilities of microbiome analysis are limited, with a lack of alignment on possible biomarkers. Using bronchoalveolar lavage fluid (BALF) from ventilated adult patients suspected of VAP, we aimed to explore how key characteristics of the microbiome differ between patients with positive and negative BALF cultures and whether any differences could have a clinically relevant role.

Methods

BALF from patients suspected of VAP was analysed using 16s rRNA sequencing in order to: (1) differentiate between patients with and without a positive culture; (2) determine if there was any association between microbiome diversity and local inflammatory response; and (3) correctly identify pathogens detected by conventional culture.

Results

Thirty-seven of 90 ICU patients with suspected VAP had positive cultures. Patients with a positive culture had significant microbiome dysbiosis with reduced alpha diversity. However, gross compositional variance was not strongly associated with culture positivity (AUROCC range 0.66–0.71). Patients with a positive culture had a significantly higher relative abundance of pathogenic bacteria compared to those without [0.45 (IQR 0.10–0.84), 0.02 (IQR 0.004–0.09), respectively], and an increased interleukin (IL)-1β was associated with reduced species evenness (r_s = − 0.33, p < 0.01) and increased pathogenic bacteria presence (r_s = 0.28, p = 0.013). Untargeted 16s rRNA pathogen detection was limited by false positives, while the use of pathogen-specific relative abundance thresholds showed better diagnostic accuracy (AUROCC range 0.89–0.998).

Conclusion

Patients with positive BALF culture had increased dysbiosis and genus dominance. An increased caspase-1-dependent IL-1b expression was associated with a reduced species evenness and increased pathogenic bacterial presence, providing a possible causal link between microbiome dysbiosis and lung injury development in VAP. However, measures of diversity were an unreliable predictor of culture positivity and 16s sequencing used agnostically could not usefully identify pathogens; this could be overcome if pathogen-specific relative abundance thresholds are used.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-022-04068-z.

Invasive fungal infections in critically ill COVID-19 patients in a large tertiary university hospital in Israel

An increasing number of studies have tried to determine the incidence of invasive fungal infections (IFIs) in COVID-19 patients. Challenges in the diagnosis of pulmonary aspergillosis in these patients have led to new definitions of COVID-19-associated pulmonary aspergillosis (CAPA). The aim of this study was to determine the incidence and outcomes of and risk factors for IFIs in critically-ill COVID-19 patients, using the new definitions, in a tertiary center in Israel.

Methods

A case-controlled study (from 1 September 2020 to 31 March 2021) in which data from COVID-19 critically-ill patients with a diagnosis of IFI were collected and compared to a control group without IFI.

Results

The incidence of IFI amongst 311 COVID-19 critically-ill patients was 6.1%. 3.5% had CAPA and 3.5% had candidemia. In-hospital mortality was higher amongst patients with IFI compared to those without IFI (89.4% vs 60%, p < 0.03). The most significant predictors of IFI were cardiovascular co-morbidity and carbapenem use.

Conclusions

The low incidence of CAPA in our group of COVID-19 critically-ill patients was consistent with recent reports, underscoring the importance of differentiating between true infection and colonization. Awareness and timely diagnosis of IFIs in COVID-19 critically-ill patients are imperative considering the associated high mortality.

Lower Respiratory Tract Coinfection in the ICU: Prevalence and Clinical Significance of Coinfection Detected via Microbiological Analysis of Bronchoalveolar Lavage Fluid With a Comparison of Invasive Methodologies

Pneumonia remains a significant cause of morbidity and mortality, with increasing interest in the detection and clinical significance of coinfection. Further investigation into the impact of bronchoalveolar lavage (BAL) sampling methodology and efficient clinical utilization of microbiological analyses is needed to guide the management of lower respiratory tract infection in the ICU.

The Use of Diuretic in Mechanically Ventilated Children with Viral Bronchiolitis: a Cohort Study

Introduction

Viral bronchiolitis is a leading cause of admissions to pediatric intensive care unit (PICU). A literature review indicates that there is limited information on fluid overload and the use of diuretics in mechanically ventilated children with viral bronchiolitis. This study was conducted to understand diuretic use concerning fluid overload in this population.

Material and methods

A retrospective cohort study performed at a quaternary children’s hospital. The study population consisted of mechanically ventilated children with bronchiolitis, with a confirmed viral diagnosis on polymerase chain reaction (PCR) testing. Children with co-morbidities were excluded. Data collected included demographics, fluid status, diuretic use, morbidity and outcomes. The data were compared between groups that received or did not receive diuretics.

Result

Of the 224 mechanically ventilated children with confirmed bronchiolitis, 179 (79%) received furosemide on Day 2 of invasive ventilation. Out of these, 72% of the patients received intermittent intravenous furosemide, whereas 28% received continuous infusion. It was used more commonly in patients who had a higher fluid overload. Initial fluid overload was associated with longer duration of mechanical ventilation (median days 6 vs 4, p<0.001) and length of stay (median days 10 vs 6, p<0.001) even with the use of furosemide. Superimposed bacterial pneumonia was seen in 60% of cases and was associated with a higher per cent fluid overload at 24 hours (9.1 vs 6.3, p = 0.003).

Conclusion

Diuretics are frequently used in mechanically ventilated children with bronchiolitis and fluid overload, with intermittent dosing of furosemide being the commonest treatment. There is a potential benefit of improved oxygenation in these children, though further research is needed to quantify this benefit and any potential harm. Due to potential harm with fluid overload, restrictive fluid strategies may have a potential benefit.

Practice Guidelines for the Diagnosis of COVID-19-Associated Pulmonary Aspergillosis in an Intensive Care Setting

Coronavirus disease-2019 (COVID-19)-associated pulmonary aspergillosis (CAPA) is a new disease characterized by secondary Aspergillus mold infection in patients with COVID-19. It primarily affects patients with COVID-19 in critical state with acute respiratory distress syndrome, requiring intensive care and mechanical ventilation. CAPA has a higher mortality rate than COVID-19, posing a serious threat to affected individuals. COVID-19 is a potential risk factor for CAPA and has already claimed a massive death toll worldwide since its outbreak in December 2019. Its second wave is currently progressing towards a peak, while the third wave of this devastating pandemic is expected to follow. Therefore, an early and accurate diagnosis of CAPA is of utmost importance for effective clinical management of this highly fatal disease. However, there are no uniform criteria for diagnosing CAPA in an intensive care setting. Therefore, based on a review of existing information and our own experience, we have proposed new criteria in the form of practice guidelines for diagnosing CAPA, focusing on the points relevant for intensivists and pulmonary and critical care physicians. The main highlights of these guidelines include the role of CAPA-appropriate test specimens, clinical risk factors, computed tomography of the thorax, and non-culture-based indirect and direct mycological evidence for diagnosing CAPA in the intensive care unit. These guidelines classify the diagnosis of CAPA into suspected, possible, and probable categories to facilitate clinical decision-making. We hope that these practice guidelines will adequately address the diagnostic challenges of CAPA, providing an easy-to-use and practical algorithm to clinicians for rapid diagnosis and clinical management of the disease.

A qualitative assessment of the diagnosis and management of ventilator-associated pneumonia among critical care clinicians exploring opportunities for diagnostic stewardship

BACKGROUND

Prompt diagnosis and intervention for ventilator-associated pneumonia (VAP) is critical but can lead to overdiagnosis and overtreatment.

OBJECTIVES

We investigated healthcare provider (HCP) perceptions and challenges associated with VAP diagnosis, and we sought to identify opportunities for diagnostic stewardship.

METHODS

We conducted a qualitative study of 30 HCPs at a tertiary-care hospital. Participants included attending physicians, residents and fellows (trainees), advanced practice providers (APPs), and pharmacists. Interviews were composed of open-ended questions in 4 sections: (1) clinical suspicion and thresholds for respiratory culture ordering, (2) preferences for respiratory sample collection, (3) culture report interpretation, and (4) VAP diagnosis and treatment. Interviews transcripts were analyzed using Nvivo 12 software, and responses were organized into themes.

RESULTS

Overall, 10 attending physicians (75%) and 16 trainees (75%) trainees and APPs believed they were overdiagnosing VAP; this response was frequent among HCPs in practice 5-10 years (91%, n = 12). Increased identification of bacteria as a result of frequent respiratory culturing, misinterpretation of culture data, and fear of missing diagnosis were recognized as drivers of overdiagnosis and overtreatment. Although most HCPs rely on clinical and radiographic changes to initiate work-up, the fear of missing a diagnosis leads to sending cultures even in the absence of those changes.

CONCLUSIONS

HCPs believe that VAP overdiagnosis and overtreatment are common due to fear of missing diagnosis, overculturing, and difficulty distinguishing colonization from infection. Although we identified opportunities for diagnostic stewardship, interventions influencing the ordering of cultures and starting antimicrobials will need to account for strongly held beliefs and ICU practices.

Antibiotic Exposure Is Not Associated With Clearance of Bronchoalveolar Growth: Results From a Prospective Ventilator-Associated Pneumonia Study

BACKGROUND

Ventilator-associated pneumonia is poorly understood in trauma. Ventilated trauma patients can develop bacterial burden without symptoms; the factors that influence this are unknown.

METHODS

Injured adults ventilated for > 2 days were enrolled. Mini-bronchoalveolar lavage was performed for 14 days or until extubation. Semi-quantitative cultures were blinded from clinicians. All cultures with > 104 colony forming units (CFU) were assessed for antibiotic exposure (ABXE) and spectrum of coverage. mBAL CFU was assessed daily.

RESULTS

60 patients were ventilated for 9 days (median). There were 75 with > 104 CFU. 46 had > 104 CFU and no ABXE on the sample day. 74% had clearance or a decrease (CoD) in CFU without ABXE. 29 had > 104 CFU and ABXE on the sample day. 19 had ABXE with pathogen coverage. 84% had CoD in CFU. 10 had ABXE with no spectrum of coverage. 1/10 had increased CFU and the remaining 9/10 CoD in CFU. The three groups were not statistically different on chi-squared analysis.

CONCLUSION

Clearance of pathogens on surveillance cultures was unaffected by ABXE.

The Use of Bronchoscopy During the Coronavirus Disease 2019 Pandemic: CHEST/AABIP Guideline and Expert Panel Report

BACKGROUND

The coronavirus disease 2019 (COVID-19) has swept the globe and is causing significant morbidity and mortality. Given that the virus is transmitted via droplets, open airway procedures such as bronchoscopy pose a significant risk to health-care workers (HCWs). The goal of this guideline was to examine the current evidence on the role of bronchoscopy during the COVID-19 pandemic and the optimal protection of patients and HCWs.

STUDY DESIGN AND METHODS

A group of approved panelists developed key clinical questions by using the Population, Intervention, Comparator, and Outcome (PICO) format that addressed specific topics on bronchoscopy related to COVID-19 infection and transmission. MEDLINE (via PubMed) was systematically searched for relevant literature and references were screened for inclusion. Validated evaluation tools were used to assess the quality of studies and to grade the level of evidence to support each recommendation. When evidence did not exist, suggestions were developed based on consensus using the modified Delphi process.

RESULTS

The systematic review and critical analysis of the literature based on six PICO questions resulted in six statements: one evidence-based graded recommendation and 5 ungraded consensus-based statements.

INTERPRETATION

The evidence on the role of bronchoscopy during the COVID-19 pandemic is sparse. To maximize protection of patients and HCWs, bronchoscopy should be used sparingly in the evaluation and management of patients with suspected or confirmed COVID-19 infections. In an area where community transmission of COVID-19 infection is present, bronchoscopy should be deferred for nonurgent indications, and if necessary to perform, HCWs should wear personal protective equipment while performing the procedure even on asymptomatic patients.

The role of mini-bronchoalveolar lavage fluid in the diagnosis of pulmonary tuberculosis in critically ill patients

BACKGROUND

The detection of Mycobacterium tuberculosis (MTB) in the intensive care unit (ICU) presents several challenges, mainly associated to the clinical state of the patient. The presence of HIV infection further aggravates this scenario, requiring a reliable collection method, with better performance in the microbiological/molecular techniques to be used. We evaluated the performance of two methods for sample collection, mini bronchoalveolar lavage (Mini-BAL) and endotracheal aspirate (ETA), for diagnosis of pulmonary tuberculosis (PTB) in critically ill patients.

METHODS

This prospective study involved 26 HIV positive ICU internalized patients, with presumptive PTB who required mechanical ventilation. Two samples were obtained prospectively from 26 HIV ICU patients with presumptive PTB by Mini-BAL and ETA. The samples were processed for smear microscopy, Löwenstein-Jensen medium and the BACTEC Mycobacteria Growth Indicator Tube 960 system®. We define as confirmed PTB patients with positive MTB culture. Furthermore, all samples obtained through the Mini-BAL were analyzed by Xpert® MTB/RIF.

RESULTS

Our results demonstrated that the respiratory samples obtained by Mini-BAL were able to increase MTB detection in critically ill patients with presumptive PTB. The Mini-BAL allowed 30% increased recovery and guaranteed enough sample volume for processing in all methods. In addition, the larger volume of the samples obtained with this technique enabled the Xpert® MTB/RIF molecular test for diagnosis of TB.

CONCLUSIONS

The Mini-BAL showed be an acceptable alternative to ETA in this population, since these critically ill and often-immunocompromised patients are more likely to develop complications related to invasive procedures.

Diagnosis of severe respiratory infections in immunocompromised patients

An increasing number of critically ill patients are immunocompromised. Acute hypoxemic respiratory failure (ARF), chiefly due to pulmonary infection, is the leading reason for ICU admission. Identifying the cause of ARF increases the chances of survival, but may be extremely challenging, as the underlying disease, treatments, and infection combine to create complex clinical pictures. In addition, there may be more than one infectious agent, and the pulmonary manifestations may be related to both infectious and non-infectious insults. Clinically or microbiologically documented bacterial pneumonia accounts for one-third of cases of ARF in immunocompromised patients. Early antibiotic therapy is recommended but decreases the chances of identifying the causative organism(s) to about 50%. Viruses are the second most common cause of severe respiratory infections. Positive tests for a virus in respiratory samples do not necessarily indicate a role for the virus in the current acute illness. Invasive fungal infections (Aspergillus, Mucorales, and Pneumocystis jirovecii) account for about 15% of severe respiratory infections, whereas parasites rarely cause severe acute infections in immunocompromised patients. This review focuses on the diagnosis of severe respiratory infections in immunocompromised patients. Special attention is given to newly validated diagnostic tests designed to be used on non-invasive samples or bronchoalveolar lavage fluid and capable of increasing the likelihood of an early etiological diagnosis.

Personalizing the Management of Pneumonia

Pneumonia is a highly prevalent disease with considerable morbidity and mortality. However, diagnosis and therapy still rely on antiquated methods, leading to the vast overuse of antimicrobials, which carries risks for both society and the individual. Furthermore, outcomes in severe pneumonia remain poor. Genomic techniques have the potential to transform the management of pneumonia through deep characterization of pathogens as well as the host response to infection. This characterization will enable the delivery of selective antimicrobials and immunomodulatory therapy that will help to offset the disorder associated with overexuberant immune responses.

Factors associated with lung cytology as obtained by non-endoscopic broncho-alveolar lavage in group-housed calves

BACKGROUND

Respiratory infections are the main indication for antimicrobial use in calves. As in humans and horses, studying inflammation of the deep airways by lung cytology raises the possibility of preventing respiratory disease and targeting its treatment in the future. Whether lung cytology findings coincide with clinical signs and lung ultrasonographic findings is currently unknown. Therefore, the objective of the present study was to determine the association of lung cytology with clinical signs, lung consolidation and broncho-alveolar lavage fluid (BALf) characteristics (including bacteriology). A total of 352 indoor group-housed calves aged between 1 and 6 months from 62 conveniently selected commercial herds were included in this cross-sectional study. Clinical examination, thoracic ultrasound and bacteriology and cytology on non-endoscopic broncho-alveolar lavage (nBAL) samples were performed.

RESULTS

Pneumonia, defined as presence of ultrasonographic lung consolidations ≥1 cm in depth, affected 42.4% of the calves. Mean BALf neutrophil percentage was 36.6% (SD 23.8; R 0-97.4) and only a positive induced tracheal cough reflex (P = 0.04), standing posture (P = 0.03) increased breathing rate (P = 0.02) and isolation of Pasteurella multocida (P = 0.005), were associated with increased neutrophil percentage. No significant associations between lung ultrasonographic findings and cytology results were present, except for presence of basophils in BALf and consolidation of > 3 cm in depth (OR = 2.6; CI = 1.2-5.6; P = 0.01). Abnormal lung sounds were associated with detection of eosinophils in BALf (OR = 2.8; CI = 1.0-8.1; P = 0.05). Total nucleated cell count (TNCC) (P <  0.001) was positively and macrophage percentage (P = 0.02) negatively associated with volume of lavage fluid recovered. Macroscopic blood staining of BALf increased TNCC (P = 0.002) and lymphocyte percentage (P = 0.001).

CONCLUSIONS

Only a limited number of clinical signs and ultrasonographic findings were associated with nBAL cytology. BALf cytology offers additional and distinct information in calves aiding in detection and prevention of respiratory conditions. In this population, selected from herds not reporting any recent respiratory illness, a high number of calves had ultrasonographic lung consolidation and high neutrophil percentage in BALf, suggesting that subclinical disease presentations frequently occur.

Evaluation of Microorganisms Causing Ventilator-Associated Pneumonia in a Pediatric Intensive Care Unit

OBJECTIVE

The aim of this study was to identify microorganisms causing ventilator-associated pneumonia (VAP) and also study the antibiotic resistance/susceptibility.

MATERIALS AND METHODS

We retrospectively assessed microorganisms isolated from patients diagnosed with VAP in a pediatric intensive care unit between January 1, 2014, and June 30, 2016.

RESULTS

We included 44 patients diagnosed with VAP. The prevalence thereof was 8.6 patients per 1,000 ventilator days. Mechanical ventilation was required for 56.5% of patients. Thirty-three patients (75%) died. An underlying chronic disease was detected in 75% of patients (n=33). Fifty microorganisms were isolated from 44 patients. Single microorganisms were isolated from 86.4% (n=38) and two from 13.6% (n=6) of patients. Of all the isolated bacteria, 96% (n=48) were gram-negative; the most common was Pseudomonas aeruginosa (32%), followed by Klebsiella pneumoniae (24%) and Acinetobacter baumannii (22%). The isolates were most susceptible to colistin (92.6%), followed by piperacillin-tazobactam (71.4%), amikacin (65.2%), and gentamicin (52.2%). No enterobacterium or Acinetobacter strain was resistant to colistin; however, 13% of P. aeruginosa isolates were resistant.

CONCLUSION

In VAP, it is essential to catalog antibiotic resistance patterns of bacteria present in the unit to ensure that empirical antibiotic therapy is effective.

Chlorhexidine decreases the risk of ventilator-associated pneumonia in intensive care unit patients: a randomized clinical trial

BACKGROUND AND OBJECTIVE

The aim was to evaluate whether oral swabbing with 0.2% chlorhexidine gluconate (CHX) decreases the risk of ventilator-associated pneumonia (VAP) in intensive care unit (ICU) patients.

MATERIAL AND METHODS

Sixty-one dentate patients scheduled for invasive mechanical ventilation for at least 48 h were included in this randomized, double-blind, controlled study. As these patients were variably incapacitated, oral care was provided by swabbing the oral mucosa four times/d with CHX in the CHX group (29 patients) and with saline in the control group (32 patients). Clinical periodontal measurements were recorded, and lower-respiratory-tract specimens were obtained for microbiological analysis on admission and when VAP was suspected. Pathogens were identified by quantifying colonies using standard culture techniques.

RESULTS

Ventilator-associated pneumonia developed in 34/61 patients (55.7%) within 6.8 d. The VAP development rate was significantly higher in the control group than in the CHX group (68.8% vs. 41.4%, respectively; p = 0.03) with an odds ratio of 3.12 (95% confidence interval = 1.09-8.91). Acinetobacter baumannii was the most common pathogen (64.7%) of all species identified. There were no significant differences between the two groups in clinical periodontal measurements, VAP development time, pathogens detected or mortality rate.

CONCLUSION

The finding of the present study, that oral care with CHX swabbing reduces the risk of VAP development in mechanically ventilated patients, strongly supports its use in ICUs and indeed the importance of adequate oral hygiene in preventing medical complications.