Lack of utility of tracheal aspirates in the management of suspected pneumonia in intubated neonates

Incidence, Risk Factors, Short-term Outcomes, and Microbiome of Ventilator-associated Pneumonia in Very-low-birth-weight Infants: Experience at a Single Level III Neonatal Intensive Care Unit

BACKGROUND

Ventilator-associated pneumonia (VAP) is a common hospital-acquired infection in neonates on invasive mechanical ventilation, resulting in high morbidity and mortality. The objective of this study is to determine the incidence, risk factors, short-term outcomes and microbiome associated with VAP in very-low-birth-weight (VLBW) infants born at <32 weeks of gestational age (GA).

METHODS

Retrospective study of intubated VLBW infants born at <32 weeks of GA admitted to the Los Angeles General Medical Center neonatal intensive care unit from July 2015 to July 2021 who had routine tracheal aspirate cultures obtained. Neonates were retrospectively classified into 3 groups, confirmed VAP, suspected VAP and no VAP, for comparison of risk factors, outcomes and airway microbial colonization.

RESULTS

Eighty-seven infants met inclusion criteria with a mean GA of 26.1 ± 1 weeks and mean birth weight of 812 ± 281 g. The incidence of VAP was 7.8 per 1000 ventilator days, and the most common causative organisms were Gram-positive organisms (39%), predominantly coagulase-negative Staphylococcus. Duration of postnatal dexamethasone exposure predicted VAP compared to no VAP (coefficient, 0.31; 95% CI 0.03-0.59; P = 0.03) after adjusting for duration of intubation, surfactant use and antenatal steroid exposure. Infants with VAP had higher rate of grade 2/3 bronchopulmonary dysplasia (P = 0.03) and longer hospital stay (P = 0.04).

CONCLUSIONS

VAP occurs at a high rate in VLBW infants who are exposed to prolonged dexamethasone use. It is predominantly caused by Gram-positive organisms.

The spectrum of pneumonia among intubated neonates in the neonatal intensive care unit

We review the pathophysiology, epidemiology, diagnosis, treatment, and prevention of ventilator-associated pneumonia (VAP) in neonates. VAP has been studied primarily in adult ICU patients, although there has been more focus on pediatric and neonatal VAP (neo-VAP) in the last decade. The definition as well as diagnosis of VAP in neonates remains a challenge to date. The neonatal intensivist needs to be familiar with the current diagnostic tools and prevention strategies available to treat and reduce VAP to reduce neonatal morbidity and the emergence of antibiotic resistance. This review also highlights preventive strategies and old and emerging treatments available.

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.

Moving Bronchopulmonary Dysplasia Research from the Bedside to the Bench

Although advances in the respiratory management of extremely preterm infants have led to improvements in survival, this progress has not yet extended to a reduction in the incidence of bronchopulmonary dysplasia (BPD). BPD is a complex multifactorial condition that primarily occurs due to disturbances in the regulation of normal pulmonary airspace and vascular development. Preterm birth and exposure to invasive mechanical ventilation also compromises large airway development, leading to significant morbidity and mortality. Although both predisposing and protective genetic and environmental factors have been frequently described in the clinical literature, these findings have had limited impact on the development of effective therapeutic strategies. This gap is likely because the molecular pathways that underlie these observations are yet not fully understood, limiting the ability of researchers to identify novel treatments that can preserve normal lung development and/or enhance cellular repair mechanisms. In this review article, we will outline various well-established clinical observations whilst identifying key knowledge gaps that need to be filled with carefully designed pre-clinical experiments. We will address these issues by discussing controversial topics in the pathophysiology, the pathology and the treatment of BPD, including an evaluation of existing animal models that have been used to answer important questions.

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?

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.