The lack of specificity of tracheal aspirates in the diagnosis of pulmonary infection in intubated children

Pneumonia in Children With Complex Chronic Conditions With Tracheostomy: An Emerging Challenge

BACKGROUND

Despite respiratory infections being a leading cause of hospitalization in children with tracheostomy tubes, there are no published guidelines for their diagnosis and management. This study aims to outline the clinical, laboratory and microbiological aspects of pneumonia in these children, along with the antibiotics used and outcomes. Additionally, it seeks to determine pneumonia incidence and associated risk factors.

METHODS

We conducted a retrospective study using the medical records of tracheostomized children at La Paz University Hospital in Madrid from 2010 to 2021.

RESULTS

Thirty-three pneumonia cases were observed in 25 tracheostomized children. Pseudomonas aeruginosa was the predominant bacterium (52%), followed by Escherichia coli , Staphylococcus aureus and Serratia marcescens . The same microorganism isolated in the tracheal aspirate culture during pneumonia was previously isolated in 83% of cases that had a similar culture, with some growth obtained within 7-30 days prior. Multiplex respiratory PCR detected respiratory viruses in 73% of cases tested. Antibiotic treatment was administered in all cases except 1, mostly intravenously (81%), with piperacillin/tazobactam and meropenem being commonly used. Only 1 of the described episodes had a fatal outcome.

CONCLUSIONS

It is advisable to include coverage for P. aeruginosa , E. coli , S. aureus , and S. marcescens in the empirical antibiotic treatment for pneumonia in tracheostomized children, along with the microorganisms identified in tracheal cultures obtained within 7-30 days prior, if available. A positive PCR for respiratory viruses is often discovered in bacterial pneumonia in tracheostomized children.

Patient factors associated with positive respiratory cultures following tracheostomy in pediatric patients

OBJECTIVES

An increasing number of pediatric patients undergo tracheostomy placement annually. Despite advances in care, these patients remain at high risk for postoperative complications, including respiratory infections. The risk factors for positive respiratory cultures and the impact of culture positivity on overall morbidity and mortality in this population is not fully characterized.

STUDY DESIGN AND SETTING

Retrospective cross-sectional analysis of all patients within a single tertiary care institution who underwent tracheostomy placement from January 1, 2019 to 12/31/2021.

METHODS

We collected patient demographic information, comorbidities, primary indication for tracheostomy placement, and respiratory culture information preoperatively and postoperatively. The primary outcome measure was positive bacterial respiratory culture with speciation within 1, 3, or 6 months of tracheostomy placement. The secondary outcome measure was all-cause mortality within the study period.

RESULTS

A total of 180 patients with median (IQR) age of 5.2 (3.4-31.0) months at time of tracheostomy placement were included in the study. Nearly half of patients had a positive culture within 1 month (n = 81,47.4 %) while 63.7 % of patients were positive within 6 months of tracheostomy placement (n = 109). Risk factors included respiratory and/or cardiac comorbidities. Positive respiratory cultures within 6 months of surgery and cardiac and/or neurologic comorbidities were associated with increased all-cause mortality following tracheostomy placement.

CONCLUSIONS

Positive respiratory cultures are common following tracheostomy placement, more so in patients with cardiac and pulmonary comorbid conditions. Positive cultures are associated with increased all-cause mortality. More work is necessary to determine optimal screening frequency and treatment protocols for positive cultures in this population.

Ventilator-associated respiratory infections in children on home invasive mechanical ventilation

Ventilator-associated respiratory tract infections (VARTI) are among the most common indications for hospitalization among children with chronic respiratory failure requiring at-home ventilation. This review aims to provide an overview of the key clinical features, diagnostic approaches, and management strategies for home VARTIs while highlighting the challenges in diagnosis and management.

Repeat tracheal aspirate cultures in pediatric intensive care patients: Frequency, resistance, and antimicrobial use

OBJECTIVE

To evaluate the clinical impact and features associated with repeat tracheal aspirate (TA) cultures in children admitted to the intensive care unit.

DESIGN

Retrospective cohort study.

SETTING

A 338-bed freestanding, tertiary pediatric academic medical center with pediatric medical intensive care unit (PICU) and cardiac intensive care units (CICU).

PATIENTS

Children ≤18 years of age who were admitted to either the PICU or CICU who had ≥2 TA cultures in a single intensive care admission.

METHODS

Patients with ≥2 TA cultures between 2018 and 2019 were included in this study. The following information was collected: patient demographics, clinical data summarizing patient condition at the time of culture collection, number of TA cultures per patient, antibiotic usage, and microbiologic data. Descriptive statistics established the frequency of TA collection, time between culturing, clinical reasoning for collection, antibiotic exposure, and development of multidrug-resistant organisms (MDRO).

RESULTS

Sixty-three patients had repeat TA cultures and accounted for 252 TA cultures during the study period. Most patients with repeat TA cultures were admitted to the PICU (71%) and were male (65%). A median of 3 TA cultures per patient were obtained with 50% of repeat cultures occurring within 7 days from the previous culture. Sixty-six percent of patients had the same organism cultured on ≥2 TA cultures. Most antibiotics were not modified or continued to treat the results of the TA culture.

CONCLUSIONS

Repeat TA cultures frequently show the same pathogens, and results do not often influence antibiotic selection or usage. Repeat TA cultures did demonstrate the development of MDROs.

A Survey of PICU Clinician Practices and Perceptions regarding Respiratory Cultures in the Evaluation of Ventilator-Associated Infections in the BrighT STAR Collaborative

OBJECTIVES

To characterize respiratory culture practices for mechanically ventilated patients, and to identify drivers of culture use and potential barriers to changing practices across PICUs.

DESIGN

Cross-sectional survey conducted May 2021-January 2022.

SETTING

Sixteen academic pediatric hospitals across the United States participating in the BrighT STAR Collaborative.

SUBJECTS

Pediatric critical care medicine physicians, advanced practice providers, respiratory therapists, and nurses.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We summarized the proportion of positive responses for each question within a hospital and calculated the median proportion and IQR across hospitals. We correlated responses with culture rates and compared responses by role. Sixteen invited institutions participated (100%). Five hundred sixty-eight of 1,301 (44%) e-mailed individuals completed the survey (median hospital response rate 60%). Saline lavage was common, but no PICUs had a standardized approach. There was the highest variability in perceived likelihood (median, IQR) to obtain cultures for isolated fever (49%, 38-61%), isolated laboratory changes (49%, 38-57%), fever and laboratory changes without respiratory symptoms (68%, 54-79%), isolated change in secretion characteristics (67%, 54-78%), and isolated increased secretions (55%, 40-65%). Respiratory cultures were likely to be obtained as a "pan culture" (75%, 70-86%). There was a significant correlation between higher culture rates and likelihood to obtain cultures for isolated fever, persistent fever, isolated hypotension, fever, and laboratory changes without respiratory symptoms, and "pan cultures." Respondents across hospitals would find clinical decision support (CDS) helpful (79%) and thought that CDS would help align ICU and/or consulting teams (82%). Anticipated barriers to change included reluctance to change (70%), opinion of consultants (64%), and concern for missing a diagnosis of ventilator-associated infections (62%).

CONCLUSIONS

Respiratory culture collection and ordering practices were inconsistent, revealing opportunities for diagnostic stewardship. CDS would be generally well received; however, anticipated conceptual and psychologic barriers to change must be considered.

Microbiological patterns of bacterial infections in tracheostomized children: Reducing uncertainty in continuous care

BACKGROUND AND OBJECTIVES

Respiratory infections are the most frequent cause of hospitalization in tracheostomized children. However, there is a lack of publications to guide their management. The primary objective was to describe the microbiological isolates and their antibiotic susceptibilities of bacterial respiratory infections in a population of tracheostomized children.

METHODS

Retrospective follow-up study of children with tracheostomy seen at a tertiary hospital. Respiratory infection episodes in patients under 18 years of age who had a tracheostomy and bacterial isolation with a count ≥104 Colony Forming Units/mL in tracheal aspirate were included.

RESULTS

The study analyzed 328 respiratory infection episodes: 164 tracheobronchitis (50%), 112 nonspecific respiratory episodes (34.1%), and 52 pneumonias (15.9%). The most commonly isolated microorganisms were Pseudomonas aeruginosa, Serratia marcescens, and Staphylococcus aureus. The antibiotics that exhibited the highest effectiveness were meropenem (92%), imipenem (87%), and levofloxacin (86%). When hospitalization exceeded 7 days, there was a higher chance of isolating Escherichia coli and Klebsiella pneumoniae (p < 0.001 and p = 0.001, respectively), as well as an increased rate of multidrug resistance (27% vs. 7%, p = 0.035). In 75.3% of cases, the microorganism had been previously isolated in a sample taken 7-30 days before the current one, with a higher frequency observed in the case of P. aeruginosa (95.2%) compared to other microorganisms (65.3%, p < 0.001).

CONCLUSIONS

Meropenem, imipenem, and levofloxacin provided the most effective coverage for these infections. The risk of multidrug resistance increased with longer hospital stays, especially for E. coli and K. pneumoniae. Recent isolation of P. aeruginosa may justify empirical coverage.

Respiratory culture organism isolation and test characteristics in children with tracheostomies with and without acute respiratory infection

BACKGROUND

Among children with tracheostomies, little is known about how respiratory culture results differ between states with and without acute respiratory infections (ARI), or the overall test performance of respiratory cultures.

OBJECTIVE

To determine the association of respiratory culture organism isolation with diagnosis of ARI in children with tracheostomies, and assess test characteristics of respiratory cultures in the diagnosis of bacterial ARI (bARI).

METHODS

This single-center, retrospective cohort study included respiratory cultures of children with tracheostomies obtained between 2010 and 2018. The primary predictor was ARI diagnosis code at the time of culture; the primary outcomes were respiratory culture organism isolation and species identified. Generalized estimating equations were used to assess for association between ARI diagnosis and isolation of any organism while controlling for potential confounders and accounting for within-patient clustering. A multinomial logistic regression equation assessed for association with specific species. Test characteristics were calculated using bARI diagnosis as the reference standard.

RESULTS

Among 3578 respiratory cultures from 533 children (median 4 cultures/child, interquartile range (IQR): 1-9), 25.9% were obtained during ARI and 17.2% had ≥1 organism. Children with ARI diagnosis had higher odds of organism identification (adjusted odds ratio 1.29, 95%  confidence interval [CI] 1.16-1.44). When controlling for covariates, ARI was associated with isolation of Haemophilus influenzae, Moraxella catarrhalis, Streptococcus pneumoniae, and Streptococcus pyogenes. Test characteristics revealed a 24.3% sensitivity, 85.2% specificity, 36.5% positive predictive value, and 76.3% negative predictive value in screening for bARI.

CONCLUSION

The utility of respiratory culture testing to screen for, diagnose, and direct treatment of ARI in children with tracheostomies is limited.

Inhaled antibiotics in children with tracheostomy tubes: A descriptive study

INTRODUCTION

Respiratory tract infections (RTIs) are common in children with tracheostomy tubes. Anecdotally, inhaled antibiotics are commonly prescribed, although to date there are no studies describing their use in this patient population. The objective of this study was to assess the variability of this practice at a single tertiary care children's hospital.

METHODS

All children admitted to our hospital with a tracheostomy tube who were prescribed inhaled antibiotics between 2013 and 2020 were included. Patient characteristics and data regarding inhaled antibiotic use were obtained retrospectively from the electronic medical record.

RESULTS

A total of 424 courses of inhaled antibiotics were prescribed during the study period. 296 (69.8%) courses were prescribed to treat an acute RTI, whereas 128 (30.2%) were prescribed prophylactically to prevent RTIs. 58.9% of children with tracheostomy tubes hospitalized during the study period received at least one course of inhaled antibiotics. The most common antibiotics prescribed were tobramycin and gentamicin; several different doses were used. In 53.2% of treatment courses, inhaled antibiotics were co-prescribed with systemic antibiotics. Therapy duration for treatment varied from 3 to 28 days. Respiratory cultures were used variably and antimicrobial susceptibility was often not taken into account when prescribing inhaled antibiotics.

CONCLUSIONS

Inhaled antibiotics were frequently prescribed as treatment and prophylaxis in children with tracheostomy tubes at our center, with significant variation in the prescribed antibiotic type, dose, frequency, duration, and co-prescription with systemic antibiotics. Prospective studies are needed to define best practice regarding inhaled antibiotics in this patient population.

The burden of central line-associated bloodstream infections in children with medical complexity

BACKGROUND

Central line-associated bloodstream infections (CLABSI) are significant cause of complications in pediatric intensive care units (PICUs). An emerging challenge are CLABSIs in children with medical complexity (CMC) admitted to PICU. CMC are patients with chronic conditions with or without neurological impairment needing for tracheostomy and/or home mechanical or non-invasive ventilation and/or gastrostomy/jejunostomy. We evaluate CLABSI incidence in a PICU with high prevalence of CMC.

METHODS

This was a retrospective study in the PICU of the Bambino Gesù Children Hospital from January 2017 to December 2020. The medical records were reviewed and demographic, clinical and microbiological data were extracted. CLABSI were defined according to the Center for Disease Control and Prevention's National Healthcare Safety Networks (NHSN) surveillance.

RESULTS

A total of 101 children with 125 central lines (CLs) were included; 79/101 (78%) patients were CMC and 50/101 (50%) had a thracheostomy. CLABSI incidence was 2.75/1000 CL-days (9 cases/3269 CL-days); incidence was 0 in patients without underling conditions and 3.14/1000 in CMC (p < 0.001). CLABSI were due to gram negative bacteria in five patients, Candida spp in three and Staphylococcus hominis in one. CLs were removed in eight cases while in the later one, with CLABSI due to Pseudomonas aeruginosa, a conservative strategy was adopted cause of unavailable alternative venous access and removed at discharge with negative culture. All patients recovered.

CONCLUSIONS

A target 0% CLABSI was possible in critically ill children without underling condition while a high incidence was reported in CMC and sustained by a peculiar CLABSI ecology. This ecology should be considered when a CLABSI was suspected in CMC for prompt antibiotics stewardship.

Mixed-methods process evaluation of a respiratory-culture diagnostic stewardship intervention

OBJECTIVE

To conduct a process evaluation of a respiratory culture diagnostic stewardship intervention.

DESIGN

Mixed-methods study.

SETTING

Tertiary-care pediatric intensive care unit (PICU).

PARTICIPANTS

Critical care, infectious diseases, and pulmonary attending physicians and fellows; PICU nurse practitioners and hospitalist physicians; pediatric residents; and PICU nurses and respiratory therapists.

METHODS

This mixed-methods study was conducted concurrently with a diagnostic stewardship intervention to reduce the inappropriate collection of respiratory cultures in mechanically ventilated children. We quantified baseline respiratory culture utilization and indications for ordering using quantitative methods. Semistructured interviews informed by these data and the Consolidated Framework for Implementation Research (CFIR) were then performed, recorded, transcribed, and coded to identify salient themes. Finally, themes identified in these interviews were used to create a cross-sectional survey.

RESULTS

The number of cultures collected per day of service varied between attending physicians (range, 2.2-27 cultures per 100 days). In total, 14 interviews were performed, and 87 clinicians completed the survey (response rate, 47%) and 77 nurses or respiratory therapists completed the survey (response rate, 17%). Clinicians varied in their stated practices regarding culture ordering, and these differences both clustered by specialty and were associated with perceived utility of the respiratory culture. Furthermore, group "default" practices, fear, and hierarchy were drivers of culture orders. Barriers to standardization included fear of a missed diagnosis and tension between practice standardization and individual decision making.

CONCLUSIONS

We identified significant variation in utilization and perceptions of respiratory cultures as well as several key barriers to implementation of this diagnostic test stewardship intervention.

Impact of Organism Reporting from Endotracheal Aspirate Cultures on Antimicrobial Prescribing Practices in Mechanically Ventilated Pediatric Patients

Endotracheal aspirate cultures (EACs) help diagnose lower respiratory tract infections in mechanically ventilated patients but are limited by contamination with normal microbiota and variation in laboratory reporting. Increased use of EACs is associated with increased antimicrobial prescribing, but the impact of microbiology reporting on prescribing practices is unclear. This study was a retrospective analysis of EACs from mechanically ventilated patients at Children's Hospital Colorado (CHCO) admitted between 1 January 2019 and 31 December 2019. Chart review was performed to collect all culture and Gram stain components, as well as antibiotic use directed to organisms in culture. Reporting concordance was determined for each organism using American Society for Microbiology guidelines. Days of therapy were calculated for overreported and guideline-concordant organisms. A multivariable model was used to assess the relationship between organism reporting and total days of therapy. Overall, 448 patients with 827 EACs were included in this study. Among patients with tracheostomy, 25 (8%) organisms reported from EACs were overreported and contributed 48 days of excess therapy, while 227 (29%) organisms from the EACs of endotracheally intubated patients were overreported, contributing 472 excess days of therapy. After adjustment, organism overreporting was associated with a >2-fold-higher rate of antimicrobial therapy than guideline-concordant reporting (incident rate ratio [IRR], 2.83; 95% confidence interval [CI], 1.23, 6.53; P < 0.05). Overreported organisms from respiratory cultures contribute to excess antimicrobial therapy exposure in mechanically ventilated patients. Microbiology laboratories have an opportunity to mitigate antimicrobial overuse through standardized reporting practices.

Comparison of tracheal aspirate and bronchoalveolar lavage samples in the microbiological diagnosis of lower respiratory tract infection in pediatric patients

BACKGROUND

Bacterial cultures from tracheal aspirates (TA) and bronchoalveolar lavage (BAL) specimens can be used to assess patients with artificial airways for lower respiratory tract infections (LRTI). TA collection may be advantageous in situations of limited resources or critical illness. Literature comparing these diagnostic modalities in pediatric populations is scarce.

METHODS

Single-center, retrospective analysis of 52 pediatric patients with an artificial airway undergoing evaluation for LRTI. All patients had a TA specimen collected for semiquantitative Gram stain and culture followed by BAL within 48 h. Microbiologic diagnosis of LRTI was defined as a BAL sample with >25% neutrophils and growth of >104 colony-forming units/ml of one or more bacterial species. The test characteristics of TA were compared with these BAL results as the reference standard. Concordance in microorganism identification was also assessed.

RESULTS

Overall, 24 patients (47%) met criteria for LRTI using BAL as the diagnostic standard. TA samples positive for an isolated organism had poor sensitivity for acute LRTI when compared with BAL, regardless of semiquantitative white blood cell (WBC) count by Gram stain. Using a TA diagnostic threshold of organism growth and at least "moderate" WBC yielded a specificity of 93%. Positive predictive value was highest when an organism was identified by TA. Negative predictive value was >70% for TA samples with no WBC by semiquantitative analysis, with or without growth of an organism. Complete concordance of cultured species was 58% for all patients, with a higher rate seen among those with endotracheal tubes.

CONCLUSIONS

The role of cultures obtained by TA remains limited for the diagnosis of acute LRTI as demonstrated by the poor correlation to BAL results within our cohort. Optimal strategies for diagnosing LRTI across patient populations and airway types remain elusive.

Improving management of ventilator associated tracheitis in a level IV NICU

BACKGROUND

There are no published guidelines regarding the diagnosis and treatment of ventilator-associated tracheitis (VAT) in the neonatal intensive care unit (NICU). VAT is likely over-diagnosed and over-treated, increasing antibiotic burden and cost.

LOCAL PROBLEM

Diagnosis and treatment of VAT were entirely NICU provider dependent.

METHODS

Retrospective pre- and post-intervention chart reviews were performed.

INTERVENTIONS

A VAT diagnosis and treatment algorithm was created for use in the care of intubated patients without tracheostomies. 3 plan-do-study-act (PDSA) cycles were used to implement change.

RESULTS

Intubated patients treated for VAT with <25 PMNs on Gram stain decreased from 79% to 35% following the quality improvement (QI) initiative. Treatment of VAT with >7 days of antibiotic therapy decreased from 42% to 10%.

CONCLUSION

Implementing a QI initiative to improve the diagnosis and treatment of VAT in the NICU decreased the percent of patients treated inappropriately for VAT.

Systematic Endotracheal Aspiration in the Pediatric Intensive Care Unit Reduces Broad-spectrum Antibiotic Use for Ventilator-associated Pneumonia

AIM

To determine the impact of a systematic endotracheal aspiration (ETA) sampling program for mechanically ventilated patients on initial antibiotic therapy for ventilator-acquired pneumonia (VAP).

DESIGN

Retrospective cohort study; before-after study design.

SETTING

Pediatric intensive care unit (PICU) with 16 medical and surgical beds in a tertiary teaching hospital.

SUBJECTS

Patients <16 years of age hospitalized in the PICU who fulfilled VAP criteria.

INTERVENTION

Biweekly systematic ETA sampling was conducted in mechanically ventilated patients.

MEASUREMENTS

We retrospectively studied patients who received antibiotic therapy for suspected VAP 12 months before and after the initiation of systematic ETA (periods 1 and 2, respectively), evaluating the initial antibiotic therapy spectrum in both periods.

RESULTS

During period 1, 56 patients developed VAP and 47 developed VAP during period 2. The incidence was 17 cases of VAP/1000 days of mechanical ventilation in both periods. Ideal antibiotic therapy was prescribed in 19.6% of cases for period 1 and 55.2% for period 2 (P = 0.001). Initial antibiotic therapy for VAP during period 2 had a significantly lower proportion of broad-spectrum antibiotics than therapy during period 1 (P = 0.01).

CONCLUSION

In our PICU, knowledge of bronchial colonization reduced initial broad-spectrum antibiotic use for VAP.

Tracheobronchitis in children with tracheostomy tubes: Overview of a challenging problem

Tracheobronchitis is common in children with tracheostomy tubes. These children are predisposed to respiratory infections due to the bypassing of normal upper airway defense mechanisms by the tracheostomy, bacterial colonization of the tracheostomy tube itself, and underlying medical conditions. Diagnosis of bacterial tracheobronchitis is challenging due to the difficulty in differentiating between bacterial colonization and infection, as well as between viral and bacterial etiologies. Difficulty in diagnosis complicates management decisions, and there are currently no consensus guidelines to assist clinicians in the treatment of these patients. Frequent administration of systemic antibiotics causes adverse effects and leads to the emergence of resistant organisms. Topical administration of antibiotics via nebulization or direct instillation may lead to a significantly higher concentration of drug in the upper and lower airways without causing systemic side effects, although therapeutic trials in children with tracheostomy tubes are lacking. Several preventative measures such as regular airway clearance and the use of a speaking valve may mitigate the risk of developing respiratory infections.

Diagnostic Stewardship in the Pediatric Intensive Care Unit

In the pediatric intensive care unit (PICU), clinicians encounter complex decision making, balancing the need to treat infections promptly against the potential harms of antibiotics. Diagnostic stewardship is an approach to optimize microbiology diagnostic test practices to reduce unnecessary antibiotic treatment. We review the evidence for diagnostic stewardship of blood, endotracheal, and urine cultures in the PICU. Clinicians should consider 3 questions applying diagnostic stewardship: (1) Does the patient have signs or symptoms of an infectious process? (2) What is the optimal diagnostic test available to evaluate for this infection? (3) How should the diagnostic specimen be collected to optimize results?

Practice Summary of Antimicrobial Therapy for Commonly Encountered Conditions in the Neonatal Intensive Care Unit: A Canadian Perspective

Neonates are highly susceptible to infections owing to their immature cellular and humoral immune functions, as well the need for invasive devices. There is a wide practice variation in the choice and duration of antimicrobial treatment, even for relatively common conditions in the NICU, attributed to the lack of evidence-based guidelines. Early decisive treatment with broad-spectrum antimicrobials is the preferred clinical choice for treating sick infants with possible bacterial infection. Prolonged antimicrobial exposure among infants without clear indications has been associated with adverse neonatal outcomes and increased drug resistance. Herein, we review and summarize the best practices from the existing literature regarding antimicrobial use in commonly encountered conditions in neonates.

Association of Endotracheal Aspirate Culture Variability and Antibiotic Use in Mechanically Ventilated Pediatric Patients

IMPORTANCE

Endotracheal aspirate cultures are commonly collected from patients with mechanical ventilation to evaluate for ventilator-associated pneumonia or tracheitis. However, the respiratory tract is not sterile, making differentiating between colonization from bacterial infection challenging, and results may be unreliable owing to variable specimen quality and sample processing across laboratories. Despite these limitations, clinicians routinely interpret bacterial growth in endotracheal aspirate cultures as evidence of infection, sometimes regardless of organism significance, prompting antibiotic treatment.

OBJECTIVE

To assess the variability in endotracheal aspirate culture rates and the association between culture rates and antibiotic prescribing among patients with mechanical ventilation across children's hospitals in the US.

DESIGN, SETTING, AND PARTICIPANTS

Cross-sectional retrospective analysis of data obtained from the Children's Hospital Association Pediatric Health Information System database between January 1, 2016, through December 31, 2019. Participants were all patients hospitalized with mechanical ventilation aged less than 18 years.

EXPOSURES

A charge for an endotracheal aspirate culture on a ventilated day.

MAIN OUTCOMES AND MEASURES

Endotracheal aspirate culture rate and antibiotic days of therapy per ventilated days. For mechanical ventilation, clinical transaction classification codes for mechanical ventilation other unspecified ventilator assistance were used. To identify respiratory cultures, the laboratory test code for aerobic culture was used and relevant keywords (ie, respiratory tract, sputum) were used to identify sources in the hospital charge description master.

RESULTS

A total of 152 132 patients were identified among 31 hospitals. Among these patients, 79 691 endotracheal aspirate cultures were collected on a ventilator-day (patients aged less than 1 year, 44%; 1-4 years, 27%, 5-11 years. 16%, and 12-18 years, 13%; 3% were Asian; 17% Hispanic; 21% non-Hispanic Black; 45% Non-Hispanic White patients; 14% were other; 56% of patients were male, 44% were female). The overall median rate of culture use was 46 per 1000 ventilator-days (IQR, 32-73 cultures per 1000 ventilator-days). The endotracheal aspirate culture rate was positively correlated with the hospital's antibiotic days of therapy rate (R = 0.46; P = .009). In a multivariable model adjusting for patient-level and hospital-level characteristics and among patients with mechanical ventilation, each additional endotracheal aspirate culture was associated with 2.87 (95% CI, 2.74-3.01) higher odds of receiving additional days of therapy compared with patients who did not receive and endotracheal aspirate culture.

CONCLUSIONS AND RELEVANCE

In this study, notable variability was found in endotracheal aspirate culture rates across US pediatric hospitals and pediatric intensive care units, and endotracheal aspirate culture use was associated with increased antibiotic use. These findings suggest an opportunity for diagnostic and antibiotic stewardship to standardize testing and treatment of suspected ventilator-associated infections in pediatric patients with mechanical ventilation pediatric patients.

Care of children with home mechanical ventilation in the healthcare continuum

Introduction:The care of children with invasive home mechanical ventilation (HMV) is challenging and insufficiently described in the literature. Objectives:Our objective regarding this unique and growing population is to describe our institution's pediatric chronic HMV program and discuss our current understanding of best care practices. Methods: In addition to characterizing the clinical landscape of our program, we describe demographics for our roughly 223 current HMV patients with comparisons to available national data.  We discuss evidence and expert opinion regarding various elements of care including initiation of HMV, caregiver education, equipment concerns, inpatient care, and longitudinal care.Results: Data was collected but not statistically analyzed for our roughly 223 current patients and historical cohort. Descriptive data included demographic information, patient medical characteristics and complexity, and reasons for rehospitalizations.Conclusions:While we have provided institutional expertise regarding the care of this complex population, the evidence base remains insufficient and there are many areas which need future research to develop standardized care practice guidelines for children with HMV.

Compliance With an Antibiotic Guideline for Suspected Ventilator-Associated Infection: The Ventilator-Associated INfection (VAIN2) Study

OBJECTIVES

To evaluate a guideline for antibiotic decisions in children with suspected ventilator-associated infection.

DESIGN

Prospective, observational cohort study conducted in 22 PICUs in the United States and Canada.

SETTING

PICUs in 22 hospitals from April 2017 to January 2019.

SUBJECTS

Children less than 3 years old on mechanical ventilation greater than 48 hours who had respiratory secretions cultured and antibiotics initiated for suspected ventilator-associated infection.

INTERVENTIONS

After baseline data collection in children with suspected ventilator-associated infection (Phase 1), a consensus guideline was developed for advising antibiotic continuation or stopping at 48-72 hours (Phase 2) and implemented (Phase 3). Guideline-based antibiotic recommendations were provided to the treating clinicians once clinical and microbiologic data were available. Demographic and outcome data were collected, and guideline compliance and antibiotic utilization evaluated for Phase 1 and Phase 3.

MEASUREMENTS AND MAIN RESULTS

Despite education and implementation efforts, guideline-concordant antibiotic management occurred in 158 of 227 (70%) Phase 3 subjects compared with 213 of 281 (76%) in Phase 1. Illness severity and positive respiratory cultures were the primary determinants of antibiotic continuation. For subjects with a positive respiratory culture but a score for which antibiotic discontinuation was recommended (score ≤ 2), only 27% of Phase 3 subjects had antibiotics discontinued. Antibiotic continuation was not associated with improved outcomes in these subjects and was associated with significantly longer duration of ventilation (median 5.5 d longer) and PICU stay (5 d longer) in the overall study population. Positive respiratory cultures were not associated with outcomes irrespective of antibiotic treatment.

CONCLUSIONS

Antibiotic guideline efficacy and safety remain uncertain due to clinician failure to follow the guideline, instead primarily relying on respiratory culture results. Strategies to overcome clinician perceptions of respiratory cultures and other barriers will be vital for improving guideline adherence and antibiotic use in suspected ventilator-associated infection in future studies.

Diagnostic Stewardship of Endotracheal Aspirate Cultures in a PICU

BACKGROUND

Clinicians commonly obtain endotracheal aspirate cultures (EACs) in the evaluation of suspected ventilator-associated infections. However, bacterial growth in EACs does not distinguish bacterial colonization from infection and may lead to overtreatment with antibiotics. We describe the development and impact of a clinical decision support algorithm to standardize the use of EACs from ventilated PICU patients.

METHODS

We monitored EAC use using a statistical process control chart. We compared the rate of EACs using Poisson regression and a quasi-experimental interrupted time series model and assessed clinical outcomes 1 year before and after introduction of the algorithm.

RESULTS

In the preintervention year, there were 557 EACs over 5092 ventilator days; after introduction of the algorithm, there were 234 EACs over 3654 ventilator days (an incident rate of 10.9 vs 6.5 per 100 ventilator days). There was a 41% decrease in the monthly rate of EACs (incidence rate ratio [IRR]: 0.59; 95% confidence interval [CI] 0.51-0.67; P < .001). The interrupted time series model revealed a preexisting 2% decline in the monthly culture rate (IRR: 0.98; 95% CI 0.97-1.0; P = .01), immediate 44% drop (IRR: 0.56; 95% CI 0.45-0.70; P = .02), and stable rate in the postintervention year (IRR: 1.03; 95% CI 0.99-1.07; P = .09). In-hospital mortality, hospital length of stay, 7-day readmissions, and All Patients Refined Diagnosis Related Group severity and mortality scores were stable. The estimated direct cost savings was $26 000 per year.

CONCLUSIONS

A clinical decision support algorithm standardizing EAC obtainment from ventilated PICU patients was associated with a sustained decline in the rate of EACs, without changes in mortality, readmissions, or length of stay.

The Pediatric Endotracheal Aspirate Culture Survey (PETACS): Examining Practice Variation across Pediatric Microbiology Laboratories in the United States

In the absence of evidence-based laboratory guidelines, the workup and interpretation of tracheal aspirate (TA) cultures remains controversial and confusing within the fields of clinical microbiology, infectious diseases, and critical care. Between 22 January and 24 February 2020, we conducted a national, web-based survey of microbiology laboratory personnel in free-standing pediatric hospitals and adult hospitals containing pediatric facilities regarding the laboratory practices used for TA specimens. We hypothesized there would be substantial center-level variability in laboratory processing of TA cultures. The response rate for the survey was 48% (73/153). There was a high level of variability in the criteria used for all processes, including specimen receipt, Gram staining, and culture reporting. Most respondents (77%) reported they do not reject TA specimens based on Gram stain criteria, and 44% of labs do not require that a minimum number of Gram stain fields be reviewed prior to reporting results. Overall, nonacademic hospital laboratories and pediatric-only laboratories are more likely to identify, report, and perform susceptibility testing on organisms from TA cultures, regardless of organism quantity or predominance. There is a substantial amount of process variability among pediatric microbiology laboratories that affects TA culture reporting, and which guides treatment decisions. This variation within and among labs makes clinical outcome studies related to TA cultures difficult to interpret. This study serves as a pragmatic step in informing the development of robust clinical guidelines. Clinical outcome and implementation studies are necessary to determine the effectiveness of guidelines for TA cultures.

Optimizing the Use of Antibiotic Agents in the Pediatric Intensive Care Unit: A Narrative Review

Antibiotics are one of the most prescribed drug classes in the pediatric intensive care unit, yet the incidence of inappropriate antibiotic prescribing remains high in critically ill children. Optimizing the use of antibiotics in this population is imperative to guarantee adequate treatment, avoid toxicity and the occurrence of antibiotic resistance, both on a patient level and on a population level. Antibiotic stewardship encompasses all initiatives to promote responsible antibiotic usage and the PICU represents a major target environment for antibiotic stewardship programs. This narrative review provides a summary of the available knowledge on the optimal selection, duration, dosage, and route of administration of antibiotic treatment in critically ill children. Overall, more scientific evidence on how to optimize antibiotic treatment is warranted in this population. We also give our personal expert opinion on research priorities.

Practice Improvement for Standardized Evaluation and Management of Acute Tracheitis in Mechanically Ventilated Children

There is no consensus definition for ventilator-associated tracheitis and limited evidence to guide diagnosis and treatment. To improve acute tracheitis evaluation and management, this quality improvement project aimed to (1) improve the appropriateness of tracheal aspirate cultures while decreasing the number of unnecessary cultures by 20% and (2) decrease antibiotic use for acute tracheitis not consistent with local guidelines by 20% over 12 months among pediatric patients requiring mechanical ventilation.

Challenging the "Culture" of the Tracheal Aspirate

The tracheal aspirate (TA) culture is commonly ordered in the NICU, but it has low sensitivity and specificity, limited by contamination. Interpretation of a TA culture out of context can lead to antibiotic overuse, which should be avoided. Clinicians should practice caution in the diagnosis of congenital pneumonia and use newer, published approaches to the diagnosis of ventilator-associated pneumonia in neonates. A subset of neonatal patients with risk factors of maternal fever or chorioamnionitis requiring intubation may benefit from TA culture performed within 12 hours after birth, to help identify an organism when blood culture may be negative, and tailor antimicrobial therapies. The more invasive, but more sensitive, technique of nonbronchoscopic bronchoalveolar lavage should be considered in older infants when bacterial isolation from the lower respiratory tract is necessary, because TA culture cannot distinguish between colonization and infection in that population.

Hospital-acquired Pneumonia and Ventilator-associated Pneumonia in Children: A Prospective Natural History and Case-Control Study

BACKGROUND

Clinical trials for antibiotics designed to treat hospital-acquired and ventilator-associated bacterial pneumonias (HABP/VABP) are hampered by making these diagnoses in a way that is acceptable to the United States Food and Drug Administration and consistent with standards of care. We examined laboratory and clinical features that might improve pediatric HABP/VABP trial efficiency by identifying risk factors predisposing children to HABP/VABP and describing the epidemiology of pediatric HABP/VABP.

METHODS

We prospectively reviewed the electronic medical records of patients <18 years of age admitted to intensive and intermediate care units (ICUs) if they received qualifying respiratory support or were started on antibiotics for a lower respiratory tract infection or undifferentiated sepsis. Subjects were followed until HABP/VABP was diagnosed or they were discharged from the ICU. Clinical, laboratory and imaging data were abstracted using structured chart review. We calculated HABP/VABP incidence and used a stepwise backward selection multivariable model to identify risk factors associated with development of HABP/VABP.

RESULTS

A total of 862 neonates, infants and children were evaluated for development of HABP/VABP; 10% (82/800) of those receiving respiratory support and 12% (103/862) overall developed HABP/VABP. Increasing age, shorter height/length, longer ICU length of stay, aspiration risk, blood product transfusion in the prior 7 days and frequent suctioning were associated with increased odds of HABP/VABP. The use of noninvasive ventilation and gastric acid suppression were both associated with decreased odds of HABP/VABP.

CONCLUSIONS

Food and Drug Administration-defined HABP/VABP occurred in 10%-12% of pediatric patients admitted to ICUs. Risk factors vary by age group.

Pediatric Antimicrobial Stewardship Programs: Current Perspectives

With the rapid growth of the field of pediatric antimicrobial stewardship, there has been a marked increase in the establishment of programs dedicated to this specialty. Shared objectives of all pediatric antimicrobial stewardship programs (ASPs) include optimization of antibiotic use and improvement in clinical outcomes for children, while certain core operational strategies and metrics used to measure program effectiveness are typically utilized by pediatric ASPs. Antimicrobial stewardship is the responsibility of every individual who prescribes, dispenses, and administers antibiotics to children, and pediatric ASP principles are rooted in collaboration and cooperation. Pediatric ASPs are uniquely suited to meet the needs of the local populations they serve and the environments within which they practice while also fostering an awareness of the interconnected global nature of pediatric stewardship. As such, pediatric ASPs are well positioned to confront the evolving challenges of antimicrobial overuse and resistance.

Respiratory pathogens associated with intubated pediatric patients following hematopoietic cell transplant

BACKGROUND

We describe organisms found in the respiratory tracts of a multicenter cohort of pediatric hematopoietic cell transplant (HCT) recipients with respiratory failure.

METHODS

Twelve centers contributed up to 25 pediatric allogeneic HCT recipients requiring mechanical ventilation for respiratory failure to a retrospective database. Positive respiratory pathogens and method of obtaining sample were recorded. Outcomes were assessed using Mann-Whitney U test or chi-squared analysis.

RESULTS

Of the 222 patients in the database, ages 1 month through 21 years, 34.6% had a positive respiratory culture. 105 pathogens were identified in 77 patients; of those, 48.6% were viral, 34.3% bacterial, 16.2% fungal, and 1% parasitic. PICU mortality with a respiratory pathogen was 68.8% compared to 54.9% for those without a respiratory pathogen (P = .045). Those with a positive respiratory pathogen had longer PICU length of stay, 20 days (IQR 14.0, 36.8) vs 15 (IQR 6.5, 32.0), P = .002, and a longer course of mechanical ventilation, 17 days (IQR 10, 29.5) vs 8 (3, 17), P < .0001. Method of pathogen identification, type of pathogen, and the presence of multiple pathogens were not associated with changes in PICU outcomes.

CONCLUSIONS

In this multicenter retrospective cohort of intubated pediatric post-HCT patients, there was high variability in the respiratory pathogens identified. Type of pathogen and method of detection did not affect PICU mortality. The presence of any organism leads to increased PICU mortality, longer PICU stay, and increased duration of mechanical ventilation suggesting that early detection and treatment of pathogens may be beneficial in this population.

Acinetobacter baumannii Is a Risk Factor for Lower Respiratory Tract Infections in Children and Adolescents With a Tracheostomy

BACKGROUND

Lower respiratory tract infections (LRIs) are a major cause of hospitalization for children and adolescents with a tracheostomy. The aim of this study was to identify risk factors for LRI.

METHODS

In this retrospective study, we assessed the number of LRI and hospitalizations for LRI from 2004 to 2014 at the University Hospital Muenster Pediatric Department. We analyzed associations between LRI and clinical findings, and we cultured pathogens in tracheal aspirates (TAs) during noninfection periods. Univariable and multivariable negative, binomial regression analyses were applied to identify associations between possible risk factors and LRI.

RESULTS

Seventy-eight patients had 148 LRI, of which 99 were treated in hospital. The median number of LRI per year was 0.4. Six-hundred thirteen pathogens were detected in 315 specimens; Staphylococcus aureus (22.5%), Pseudomonas aeruginosa (14.8%) and Haemophilus influenzae (6.2%) were most frequently detected. Acinetobacter baumannii is an independent risk factor for LRI (rate ratio, 1.792; P = 0.030) and hospital admissions for LRI (rate ratio, 1.917; P = 0.011).

CONCLUSIONS

Children with a tracheostomy have frequent LRI. A. baumannii but not P. aeruginosa or S. aureus in TA is a risk factor for LRI in children with a long-term tracheostomy. This supports repetitive culture of TA for microbiologic workup to identify children and adolescents with an increased risk for LRI.

Microbiological analysis of endotracheal aspirate and endotracheal tube cultures in mechanically ventilated patients

Background

To compare the microbiological culture within endotracheal aspirate specimens (ETAs) and endotracheal tube specimens (ETTs) in patients undergoing mechanical ventilation (MV) by statistical tools.

Method

ETAs and ETTs from a total number of 81 patients, who were undergoing MV at the intensive care unit (ICU) of Jiading Central Hospital Affiliated Shanghai University of Medicine & Health Sciences from September 1st, 2017 to August 31st, 2018, were collected for microbiological culture analysis. Correlation of ETAs and ETTs cultures were obtained by Spear-men correlation analysis, while the consistency of the two specimens was determined by Kappa analysis and principal component analysis (PCA).

Results

Microbiological culture from both ETAs and ETTs showed that Acinetobacter baumannii, Pseudomonas aeruginosa, Staphylococcus aureus, and Klebsiella pneumoniae were the main pathogens, with Spear-man correlation coefficients of 0.676, 0.951, 0.730 and 0.687 respectively (all P < 0.01), and the overall Spear-man correlation coefficient is 0.757 (P < 0.01). This result shows that two samples were positively correlated. Kappa analysis also revealed high consistency of the microbial culture results from the ETAs and the ETTs (overall κ = 0.751, P < 0.01). The κ values for the four bacteria detected were 0.670, 0.949, 0.723, and 0.687, respectively (all P < 0.001). PCA also revealed high similarity.

Conclusion

Combining microbiological culture and statistical analysis of samples collected from 81 patients who were undergoing MV in ICU, we showed that microbe found in the ETAs had high similarity with that found in the ETTs which collected at the end of the catheters. In clinical practice, ETAs analysis is easily accessible meanwhile provides a valuable information for MV patients.

Electronic supplementary material

The online version of this article (10.1186/s12890-019-0926-3) contains supplementary material, which is available to authorized users.

Decision-Making Around Positive Tracheal Aspirate Cultures: The Role of Neutrophil Semiquantification in Antibiotic Prescribing

OBJECTIVES

Ventilator-associated infections are a major contributor to antibiotic use in the PICU. Quantitative or semiquantitative assessment of neutrophils (microscopic purulence) is routinely reported in positive cultures from tracheal aspirates. The role of microscopic purulence in guiding antibiotic therapy or its association with symptoms of ventilator-associated infections is less described in children. We examine microscopic purulence as an independent predictor of antibiotic use for positive tracheal aspirate cultures in the PICU.

DESIGN

Retrospective cohort study.

SETTING

Tertiary care pediatric hospital.

PATIENTS

Children admitted to the PICU, neuro-PICU, or cardiac PICU with a positive tracheal aspirate culture from January 1, 2016, to December 31, 2016.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Positive tracheal aspirate cultures were reviewed. The outcome variable was antibiotic treatment that targeted the positive tracheal aspirate culture. The predictor variable was microscopic purulence, defined as moderate or many neutrophils on Gram stain report. Competing predictors included demographics, comorbidities, vital signs changes, respiratory support, and laboratory values. Of 361 positive cultures in the cohort, 81 (22%) were treated with antibiotics. Positive cultures with microscopic purulence were targeted for therapy more frequently (30% vs 11%). Microscopic purulence was the strongest predictor for antibiotic therapy (odds ratio, 3.3; 95% CI, 1.6-6.8) compared with fever (odds ratio, 2.0; 95% CI, 1.0-4.1) or increased respiratory support (odds ratio, 2.3; 95% CI, 1.2-4.3). There was no significant variation in symptomatology between microscopic purulence reported as moderate or many versus other (e.g., fever -24% vs 22%, increased respiratory support -36% vs 28%). Microscopic purulence was less prevalent with longer ventilator durations at the time of sampling.

CONCLUSIONS

Microscopic purulence was an independent predictor of antibiotic therapy for positive tracheal aspirate cultures in our PICUs. However, microscopic purulence was not associated with clinical symptomatology.

Development of an Antibiotic Guideline for Children With Suspected Ventilator-Associated Infections

OBJECTIVES

To develop a guideline for the decision to continue or stop antibiotics at 48-72 hours after their initiation in children with suspected ventilator-associated infection.

DESIGN

Prospective, multicenter observational data collection and subsequent development of an antibiotic guideline.

SETTING

Twenty-two PICUs.

PATIENTS

Children less than 3 years old receiving mechanical ventilation who underwent clinical testing and initiation of antibiotics for suspected ventilator-associated infection.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Phase 1 was a prospective data collection in 281 invasively ventilated children with suspected ventilator-associated infection. The median age was 8 months (interquartile range, 4-16 mo) and 75% had at least one comorbidity. Phase 2 was development of the guideline scoring system by an expert panel employing consensus conferences, literature search, discussions with institutional colleagues, and refinement using phase 1 data. Guideline scores were then applied retrospectively to the phase 1 data. Higher scores correlated with duration of antibiotics (p < 0.001) and higher PEdiatric Logistic Organ Dysfunction 2 scores (p < 0.001) but not mortality, PICU-free days or ventilator-free days. Considering safety and outcomes based on the phase 1 data and aiming for a 25% reduction in antibiotic use, the panel recommended stopping antibiotics at 48-72 hours for guideline scores less than or equal to 2, continuing antibiotics for scores greater than or equal to 6, and offered no recommendation for scores 3, 4, and 5. The acceptability and effect of these recommendations on antibiotic use and outcomes will be prospectively tested in phase 3 of the study.

CONCLUSIONS

We developed a scoring system with recommendations to guide the decision to stop or continue antibiotics at 48-72 hours in children with suspected ventilator-associated infection. The safety and efficacy of the recommendations will be prospectively tested in the planned phase 3 of the study.

Antibiotic Prescription in Young Children With Respiratory Syncytial Virus-Associated Respiratory Failure and Associated Outcomes

OBJECTIVES

To describe antibiotic prescribing practices during the first 2 days of mechanical ventilation among previously healthy young children with respiratory syncytial virus-associated lower respiratory tract infection and evaluate associations between the prescription of antibiotics at onset of mechanical ventilation with clinical outcomes.

DESIGN

Retrospective cohort study.

SETTING

Forty-six children's hospitals in the United States.

PATIENTS

Children less than 2 years old discharged between 2012 and 2016 with an International Classification of Diseases diagnosis of respiratory syncytial virus-associated lower respiratory tract infection, no identified comorbid conditions, and receipt of mechanical ventilation.

INTERVENTIONS

Antibiotic prescription during the first 2 days of mechanical ventilation.

MEASUREMENTS AND MAIN RESULTS

We compared duration of mechanical ventilation and hospital length of stay between children prescribed antibiotics on both of the first 2 days of mechanical ventilation and children not prescribed antibiotics during the first 2 days of mechanical ventilation. We included 2,107 PICU children with respiratory syncytial virus-associated lower respiratory tract infection (60% male, median age of 1 mo [interquartile range, 1-4 mo]). The overall proportion of antibiotic prescription on both of the first 2 days of mechanical ventilation was 82%, decreasing over the study period (p = 0.004) and varying from 36% to 100% across centers. In the bivariate analysis, antibiotic prescription was associated with a shorter duration of mechanical ventilation (6 d [4-9 d] vs 8 d [6-11 d]; p < 0.001) and a shorter hospital length of stay (11 d [8-16 d] vs 13 d [10-18 d]; p < 0.001). After adjustment for center, demographics, and vasoactive medication prescription, antibiotic prescription was associated with a 1.21-day shorter duration of mechanical ventilation and a 2.07-day shorter length of stay. Ultimately, 95% of children were prescribed antibiotics sometime during hospitalization, but timing, duration, and antibiotic choice varied markedly.

CONCLUSIONS

Although highly variable across centers and decreasing over time, the practice of instituting antibiotics after intubation in young children with respiratory syncytial virus-associated lower respiratory tract infection was associated with a shortened clinical course after adjustment for the limited available covariates. A prudent approach to identify and optimally treat bacterial coinfection is needed.

Microbiological Diagnosis of Respiratory Illness

A wide variety of microorganisms are potential respiratory pathogens, and the spectrum of known pathogens for each respiratory infection syndrome has not changed markers over recent years. Detection of likely etiologic agents of respiratory infections can help direct management and can also play an important role in disease surveillance. For this purpose, we are still reliant on many traditional diagnostic tools that have been used for decades in order to determine the microbial etiology of respiratory infections. However, these tools have been increasingly supplemented by newer methods, particular molecular diagnostic techniques, which have enabled the more rapid detection of many pathogens that were previously difficult to detect. These advances have particularly lead to improvements in the ability to detect respiratory viruses and also other microorganisms that do not normally colonize the respiratory tract. Recognition of the existence of the lung microbiome has challenged the traditional views of pneumonia pathogenesis and may provide the opportunity for new diagnostic tools that are focused on more than just detection of specific known pathogens. Continued liaison between clinicians and laboratory staff is vital in order to facilitate the most cost-effective use of laboratory diagnostics.

Variability in antimicrobial use in pediatric ventilator-associated events

OBJECTIVE

To assess variability in antimicrobial use and associations with infection testing in pediatric ventilator-associated events (VAEs).

DESIGN

Descriptive retrospective cohort with nested case-control study.

SETTING

Pediatric intensive care units (PICUs), cardiac intensive care units (CICUs), and neonatal intensive care units (NICUs) in 6 US hospitals.PatientsChildren≤18 years ventilated for≥1 calendar day.

METHODS

We identified patients with pediatric ventilator-associated conditions (VACs), pediatric VACs with antimicrobial use for≥4 days (AVACs), and possible ventilator-associated pneumonia (PVAP, defined as pediatric AVAC with a positive respiratory diagnostic test) according to previously proposed criteria.

RESULTS

Among 9,025 ventilated children, we identified 192 VAC cases, 43 in CICUs, 70 in PICUs, and 79 in NICUs. AVAC criteria were met in 79 VAC cases (41%) (58% CICU; 51% PICU; and 23% NICU), and varied by hospital (CICU, 20-67%; PICU, 0-70%; and NICU, 0-43%). Type and duration of AVAC antimicrobials varied by ICU type. AVAC cases in CICUs and PICUs received broad-spectrum antimicrobials more often than those in NICUs. Among AVAC cases, 39% had respiratory infection diagnostic testing performed; PVAP was identified in 15 VAC cases. Also, among AVAC cases, 73% had no associated positive respiratory or nonrespiratory diagnostic test.

CONCLUSIONS

Antimicrobial use is common in pediatric VAC, with variability in spectrum and duration of antimicrobials within hospitals and across ICU types, while PVAP is uncommon. Prolonged antimicrobial use despite low rates of PVAP or positive laboratory testing for infection suggests that AVAC may provide a lever for antimicrobial stewardship programs to improve utilization.

Development and Validation of a Model to Predict Growth of Potentially Antibiotic-Resistant Gram-Negative Bacilli in Critically Ill Children With Suspected Infection

Background

Risk-based guidelines aid empiric antibiotic selection for critically ill adults with suspected infection with Gram-negative bacilli with high potential for antibiotic resistance (termed high-risk GNRs). Neither evidence-based guidelines for empiric antibiotic selection nor validated risk factors predicting high-risk GNR growth exist for critically ill children. We developed and validated a model for predicting high-risk GNR growth in critically ill children with suspected infection.

Methods

This is a retrospective cohort study involving 2 pediatric cohorts admitted to a pediatric intensive care unit (ICU) with suspected infection. We developed a risk model predicting growth of high-risk GNRs using multivariable regression analysis in 1 cohort and validated it in a separate cohort.

Results

In our derivation cohort (556 infectious episodes involving 489 patients), we identified the following independent predictors of high-risk GNR growth: hospitalization >48 hours before suspected infection, hospitalization within the past 4 weeks, recent systemic antibiotics, chronic lung disease, residence in a chronic care facility, and prior high-risk GNR growth. The model sensitivity was 96%, the specificity was 48%, performance using the Brier score was good, and the area under the receiver operator characteristic curve (AUROC) was 0.722, indicating good model performance. In our validation cohort (525 episodes in 447 patients), model performance was similar (AUROC, 0.733), indicating stable model performance.

Conclusions

Our model predicting high-risk GNR growth in critically ill children demonstrates the high sensitivity needed for ICU antibiotic decisions, good overall predictive capability, and stable performance in 2 separate cohorts. This model could be used to develop risk-based empiric antibiotic guidelines for the pediatric ICU.

Molecular analysis of endotracheal tube biofilms and tracheal aspirates in the pediatric intensive care unit

BACKGROUND

Ventilator-associated pneumonia (VAP) is a known complication of mechanically ventilated children in the pediatric intensive care unit (PICU). Endotracheal tube (ETT) biofilms are often implicated in the development of VAP by providing a conduit for pathogens to the lower respiratory tract.

METHODS

A prospective cohort study from April 2010-March 2011 of children 4 weeks to 18 years of age ventilated for greater than 72 hours to determine the microbiota of ETT biofilms and tracheal aspirates.

RESULTS

Thirty-three patients were included with a mean age of 6.1 years (SD ± 5.1 years) and average length of intubation of 8.8 days (SD ± 5.0 days). Bacterial communities from tracheal aspirates and the proximal and distal ends of ETTs were determined using 16S rRNA gene libraries. Statistical analysis utilized two-part statistics and the Wilcoxon signed rank sum test for comparison of bacterial communities. Sequencing revealed a predominance of oropharyngeal microbiota including Prevotella and Streptococcus spp. Pathogenic bacterial genera including Staphylococcus, Burkholderia, Moraxella, and Haemophilus were also represented. Bacterial load was greatest at the proximal aspect of the ETT. Duration of intubation did not significantly impact bacterial load. Morisita Horn analysis across sites showed similar communities in 24/33 (72%) of patients.

CONCLUSIONS

ETT biofilms and tracheal aspirates of intubated patients in the PICU primarily consisted of oropharyngeal microbiota, but had a significant representation of potentially pathogenic genera. While the majority of patients had similar microbiota when comparing their ETT biofilms and tracheal aspirates, a subset of patients showed a divergence between communities that requires further investigation.

Ventilator-Associated Pneumonia in Critically Ill Children: A New Paradigm

Ventilator-associated pneumonia (VAP) is a serious complication of critical illness. Surveillance definitions have undergone revisions for more objective and consistent reporting. The 1 organism-1 disease paradigm for microbial involvement may not adequately apply to many cases of VAP, in which pathogens are introduced to a pre-existing and often complex microbial community that facilitates or hinders the potential pathogen, consequently determining whether progression to VAP occurs. As omics technology is applied to VAP, a paradigm is emerging incorporating simultaneous assessments of microbial populations and their activity, as well as the host response, to personalize prevention and treatment.

Suspicion of respiratory tract infection with multidrug-resistant Enterobacteriaceae: epidemiology and risk factors from a Paediatric Intensive Care Unit

BACKGROUND

Multidrug-resistant (MDR) infections are a serious concern for children admitted to the Paediatric Intensive Care Unit (PICU). Tracheal colonization with MDR Enterobacteriaceae predisposes to respiratory infection, but underlying risk factors are poorly understood. This study aims to determine the incidence of children with suspected infection during mechanical ventilation and analyses risk factors for the finding of MDR Enterobacteriaceae in tracheal aspirates.

METHODS

A retrospective single-centre analysis of Enterobacteriaceae isolates from the lower respiratory tract of ventilated PICU patients from 2005 to 2014 was performed. Resistance status was determined and clinical records were reviewed for potential risk factors. A classification and regression tree (CRT) to predict risk factors for infection with MDR Enterobacteriaceae was employed. The model was validated by simple and multivariable logistic regression.

RESULTS

One hundred sixty-seven Enterobacteriaceae isolates in 123 children were identified. The most frequent isolates were Enterobacter spp., Klebsiella spp. and E.coli. Among these, 116 (69%) isolates were susceptible and 51 (31%) were MDR. In the CRT analysis, antibiotic exposure for ≥ 7 days and presence of gastrointestinal comorbidity were the most relevant predictors for an MDR isolate. Antibiotic exposure for ≥ 7 days was confirmed as a significant risk factor for infection with MDR Enterobacteriaceae by a multivariable logistic regression model.

CONCLUSIONS

This study shows that critically-ill children with tracheal Enterobacteriaceae infection are at risk of carrying MDR isolates. Prior use of antibiotics for ≥ 7 days significantly increased the risk of finding MDR organisms in ventilated PICU patients with suspected infection. Our results imply that early identification of patients at risk, rapid microbiological diagnostics and tailored antibiotic therapy are essential to improve management of critically ill children infected with Enterobacteriaceae.

Pediatric Ventilator-Associated Infections: The Ventilator-Associated INfection Study

OBJECTIVE

Suspected ventilator-associated infection is the most common reason for antibiotics in the PICU. We sought to characterize the clinical variables associated with continuing antibiotics after initial evaluation for suspected ventilator-associated infection and to determine whether clinical variables or antibiotic treatment influenced outcomes.

DESIGN

Prospective, observational cohort study conducted in 47 PICUs in the United States, Canada, and Australia. Two hundred twenty-nine pediatric patients ventilated more than 48 hours undergoing respiratory secretion cultures were enrolled as "suspected ventilator-associated infection" in a prospective cohort study, those receiving antibiotics of less than or equal to 3 days were categorized as "evaluation only," and greater than 3 days as "treated." Demographics, diagnoses, comorbidities, culture results, and clinical data were compared between evaluation only and treated subjects and between subjects with positive versus negative cultures.

SETTING

PICUs in 47 hospitals in the United States, Canada, and Australia.

SUBJECTS

All patients undergoing respiratory secretion cultures during the 6 study periods.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Treated subjects differed from evaluation-only subjects only in frequency of positive cultures (79% vs 36%; p < 0.0001). Subjects with positive cultures were more likely to have chronic lung disease, tracheostomy, and shorter PICU stay, but there were no differences in ventilator days or mortality. Outcomes were similar in subjects with positive or negative cultures irrespective of antibiotic treatment. Immunocompromise and higher Pediatric Logistic Organ Dysfunction scores were the only variables associated with mortality in the overall population, but treated subjects with endotracheal tubes had significantly lower mortality.

CONCLUSIONS

Positive respiratory cultures were the primary determinant of continued antibiotic treatment in children with suspected ventilator-associated infection. Positive cultures were not associated with worse outcomes irrespective of antibiotic treatment although the lower mortality in treated subjects with endotracheal tubes is notable. The necessity of continuing antibiotics for a positive respiratory culture in suspected ventilator-associated infection requires further study.

Diagnosis and Treatment of Ventilator-Associated Infection: Review of the Critical Illness Stress-Induced Immune Suppression Prevention Trial Data

OBJECTIVES

The Critical Illness Stress-Induced Immune Suppression prevention trial was a randomized, masked trial of zinc, selenium, glutamine, and metoclopramide compared with whey protein in delaying nosocomial infection in PICU patients. One fourth of study subjects were diagnosed with nosocomial lower respiratory infection, which contributed to subjects receiving antibiotics 74% of all patient days in the PICU. We analyzed diagnostic and treatment variability among the participating institutions and compared outcomes between nosocomial lower respiratory infection subjects (n = 74) and intubated subjects without nosocomial infection (n = 1 55).

DESIGN

Post hoc analysis.

SETTING

Eight hospitals in the Collaborative Pediatric Critical Care Research Network.

PATIENTS

Critical Illness Stress-Induced Immune Suppression study subjects.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Variability across institutions existed in the frequency and manner by which respiratory secretion cultures were obtained, processed, and results reported. Most results were reported semiquantitatively, and both Gram stains and antibiotic sensitivities were frequently omitted. The nosocomial lower respiratory infection diagnosis was associated with increased PICU lengths of stay compared with those who were intubated without nosocomial infection (24 ± 19 vs 9 ± 6 d; p < 0.001) and antibiotic use (38 ± 29 vs 15 ± 20 antibiotics days; p < 0.001). Despite antibiotic treatment, the same bacteria persisted in 45% of follow-up cultures.

CONCLUSIONS

The Critical Illness Stress-Induced Immune Suppression data demonstrate that the nosocomial lower respiratory infection diagnosis is associated with longer lengths of stay and increased antibiotic use, but there is considerable diagnostic and treatment variability across institutions. More rigorous standards for when and how respiratory cultures are obtained, processed, and reported are necessary. Bacterial persistence also complicates the interpretation of follow-up cultures.

Optimizing the Use of Antibacterial Agents in the Neonatal Period

Antibiotics are invaluable in the management of neonatal infections. However, overuse or misuse of antibiotics in neonates has been associated with adverse outcomes, including increased risk for future infection, necrotizing enterocolitis, and mortality. Strategies to optimize the use of antibiotics in the neonatal intensive care unit include practicing effective infection prevention, improving the diagnostic evaluation and empiric therapy for suspected infections, timely adjustment of therapy as additional information becomes available, and treating proven infections with an effective, narrow-spectrum agent for the minimum effective duration. Antibiotic stewardship programs provide support for these strategies but require the participation and input of neonatologists as stakeholders to be most effective.

Comparison of the New Adult Ventilator-Associated Event Criteria to the Centers for Disease Control and Prevention Pediatric Ventilator-Associated Pneumonia Definition (PNU2) in a Population of Pediatric Traumatic Brain Injury Patients

OBJECTIVES

The new Centers for Disease Control and Prevention paradigm for ventilator-associated events is intended to simplify surveillance of infectious and noninfectious complications of mechanical ventilation in adults. We assessed the ventilator-associated events algorithm in pediatric patients.

DESIGN

A retrospective observational cohort study.

SETTING

This single-center study took place in a PICU at an urban academic medical facility.

PATIENTS

Pediatric (ages 0-18 yr old) trauma patients with moderate-to-severe traumatic brain injury ventilated for greater than or equal to 2 days.

MEASUREMENTS AND MAIN RESULTS

We assessed for pediatric ventilator-associated pneumonia (as defined by current Centers for Disease Control and Prevention PNU2 guidelines), adult ventilator-associated events, and an experimental ventilator-associated events definition modified for pediatric patients. We compared ventilator-associated events to ventilator-associated pneumonia to calculate the test characteristics. Thirty-nine of 119 patients (33%) developed ventilator-associated pneumonia. Sensitivity of the adult ventilator-associated condition definition was 23% (95% CI, 11-39%), which increased to 56% (95% CI, 40-72%) using the modified pediatric ventilator-associated pneumonia criterion. Specificity reached 100% for both original and modified pediatric probable ventilator-associated pneumonia using ventilator-associated events criteria. Children who developed ventilator-associated pneumonia or ventilator-associated condition had similar baseline characteristics: age, mechanism of injury, injury severity scores, and use of an intracranial pressure monitor. Diagnosis of ventilator-associated pneumonia and ventilator-associated condition portended similarly unfavorable outcomes: longer median duration of ventilation, ICU and hospital length of stay, and more discharges to rehabilitation, home health, or nursing care compared with patients with no pulmonary complication.

CONCLUSIONS

Both current and modified ventilator-associated events criteria have poor sensitivity but good specificity in identifying pediatric ventilator-associated pneumonia. Despite poor sensitivity, the high specificity of the ventilator-associated events diagnoses does provide a useful and objective metric for interinstitution ICU comparison. Ventilator-associated pneumonia and ventilator-associated condition were both associated with excess morbidity in pediatric traumatic brain injury patients.