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

Severe respiratory syncytial virus disease

The burden of respiratory syncytial virus (RSV) disease is widely recognized. Main risk factors for severe disease, such as extreme ages, chronic cardiopulmonary conditions, and immunosuppression, typically coincide with poorer outcomes. While the majority of RSV hospitalizations involve healthy children, a higher proportion of hospitalized adults with underlying conditions need intensive care. Presently, treatment primarily consists of supportive measures. RSV-induced wheezing should be distinguished from respiratory tract thickening, without response to bronchodilators. Obstructive RSV disease frequently overlaps with viral pneumonia. Non-invasive mechanical ventilation and high-flow oxygen therapy represented significant advancements in the management of severe RSV disease in children and may also hold considerable importance in specific phenotypes of RSV disease in adults. Most severe infections manifest with refractory hypoxemia necessitating more advanced ventilatory support and/or extracorporeal membrane oxygenation therapy. Although bacterial co-infection rates are low, they have been associated with worse outcomes. Antibiotic prescription rates are high. Accurately diagnosing bacterial co-infections remains a challenge. Current evidence and antibiotic stewardship policies advise against indiscriminate antibiotic usage, even in severe cases. The role of currently developing antiviral therapies in severe RSV disease will be elucidated in the coming years, contingent upon the success of new vaccines and immune passive strategies involving nirsevimab.

Interactions between respiratory syncytial virus and Streptococcus pneumoniae in the pathogenesis of childhood respiratory infections: a systematic review

Lower respiratory tract infections, commonly caused by respiratory syncytial virus (RSV) or Streptococcus pneumoniae (pneumococcus), pose a substantial global health burden, especially in children younger than 5 years of age. A deeper understanding of the relationship between RSV and pneumococcus would aid the development of health-care approaches to disease prevention and management. We completed a systematic review to identify and assess evidence pertaining to the relationship between RSV and pneumococcus in the pathogenesis of childhood respiratory infections. We found mechanistic evidence for direct pathogen-pathogen interactions and for indirect interactions involving host modulation. We found a strong seasonal epidemiological association between these two pathogens, which was recently confirmed by a parallel decrease and a subsequent resurgence of both RSV and pneumococcus-associated disease during the COVID-19 pandemic. Importantly, we found that pneumococcal vaccination was associated with reduced RSV hospitalisations in infants, further supporting the relevance of their interaction in modulating severe disease. Overall evidence supports a broad biological and clinical interaction between pneumococcus and RSV in the pathogenesis of childhood respiratory infections. We hypothesise that the implementation of next-generation pneumococcal and RSV vaccines and monoclonal antibodies targeting RSV will act synergistically to reduce global morbidity and mortality related to childhood respiratory infections.

Prevalence of Bacterial Codetection and Outcomes for Infants Intubated for Respiratory Infections

OBJECTIVES

To determine the prevalence of respiratory bacterial codetection in children younger than 2 years intubated for acute lower respiratory tract infection (LRTI), primarily viral bronchiolitis, and identify the association of codetection with mechanical ventilation duration.

DESIGN

Prospective observational study evaluating the prevalence of bacterial codetection (moderate/heavy growth of pathogenic bacterial plus moderate/many polymorphonuclear neutrophils) and the impact of codetection on invasive mechanical ventilation (IMV) duration.

SETTING

PICUs in 12 high and low/middle-income countries.

PATIENTS

Children younger than 2 years old requiring intubation and ICU admission for LRTI and who had a lower respiratory tract culture obtained at the time of intubation between December 1, 2019, and November 30, 2020.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Of the 472 analyzed patients (median age 4.5 mo), 55% had a positive respiratory culture and 29% ( n = 138) had codetection. 90% received early antibiotics starting at a median of 0.36 hours after respiratory culture. Median (interquartile range) IMV duration was 151 hours (88, 226), and there were 28 deaths (5.3%). Codetection was more common with younger age, a positive respiratory syncytial virus test, and an admission diagnosis of bronchiolitis; it was less common with an admission diagnosis of pneumonia, with admission to a low-/middle-income site, and in those receiving vasopressors. When adjusted for confounders, codetection was not associated with longer IMV duration (adjusted relative risk 0.854 [95% CI 0.684-1.065]). We could not exclude the possibility that codetection might be associated with a 30-hour shorter IMV duration compared with no codetection, although the CI includes the null value.

CONCLUSIONS

Bacterial codetection was present in almost a third of children younger than 2 years requiring intubation and ICU admission for LRTI, but this was not associated with prolonged IMV. Further large studies are needed to evaluate if codetection is associated with shorter IMV duration.

Impact of Respiratory Bacterial Codetection on Outcomes in Ventilated Infants With Bronchiolitis

BACKGROUND

Viral bronchiolitis is a common cause of acute respiratory failure requiring intubation for infants. Bacterial respiratory tract infections can occur with bronchiolitis, although their prevalence and impact on outcomes are unclear, especially with increased use of noninvasive respiratory support.

METHODS

This was a single-center retrospective cohort study of children <2 years old requiring intubation in the emergency department for bronchiolitis from 2012 to 2017 who had viral testing plus a lower respiratory culture obtained. We evaluated the impact of bacterial codetection (positive respiratory culture plus moderate or many polymorphonuclear neutrophils on Gram stain) on mechanical ventilation (MV) duration and intensive care unit length of stay using multivariable gamma regression.

RESULTS

Of 149 patients enrolled, 52% had bacterial codetection. In adjusted analysis, patients with codetection had shorter MV duration [adjusted relative risk (aRR) 0.819, 95% confidence interval (CI): 0.69-0.98; marginal mean duration of 5.31 days (4.71-5.99) compared to 6.48 days (5.72-7.35) without codetection]. Patients with codetection had a shorter intensive care unit stay [aRR 0.806 (0.69-0.94); marginal mean length of stay 6.9 days (6.21-7.68) vs. 8.57 days (7.68-9.56) without codetection]. The association between codetection and duration of ventilation appears confined to those receiving earlier antibiotics (less than the median time) rather than later antibiotics [aRR 0.738 (0.56-0.95) for earlier vs. aRR 0.92 (0.70-1.18) for later].

CONCLUSIONS

Respiratory bacterial codetection is common and associated with shorter MV duration in infants requiring early intubation for bronchiolitis. Early antibiotics may contribute to these outcomes, but further multicenter studies are needed to understand the role of codetection and antibiotics on bronchiolitis outcomes.

Intensivists' Reported Management of Critical Bronchiolitis: More Data and New Guidelines Needed

OBJECTIVES

Existing bronchiolitis guidelines do not reflect the needs of infants admitted to the PICU. This study aimed to identify PICU providers' reported practice variations and explore the need for critical bronchiolitis clinical guidelines.

METHODS

Cross-sectional electronic survey available in English, Spanish, and Portuguese between November 2020 and March 2021, distributed via research networks from North and Latin America, Asia, and Australia/New Zealand.

RESULTS

A total of 657 PICU providers responded, including 344 English, 204 Spanish, and 109 Portuguese. PICU providers indicated frequently using (≥25% of time) diagnostic modalities for nonintubated and intubated patients on PICU admission (complete blood count [75%-97%], basic metabolic panel [64%-92%], respiratory viral panel [90%-95%], chest x-ray [83%-98%]). Respondents also reported regularly (≥25% of time) prescribing β-2 agonists (43%-50%), systemic corticosteroids (23%-33%), antibiotics (24%-41%), and diuretics (13%-41%). Although work of breathing was the most common variable affecting providers' decision to initiate enteral feeds for nonintubated infants, hemodynamic status was the most common variable for intubated infants (82% of providers). Most respondents agreed it would be beneficial to have specific guidelines for infants with critical bronchiolitis who are requiring both noninvasive (91% agreement) and invasive (89% agreement) respiratory support.

CONCLUSIONS

PICU providers report performing diagnostic and therapeutic interventions for infants with bronchiolitis more frequently than recommended by current clinical guidelines, with interventions occurring more frequently for infants requiring invasive support. More clinical research is needed to inform the creation of evidence-based guidelines specifically for infants with critical bronchiolitis.

Antibiotic use in nonintubated children with bronchiolitis in the intensive care unit

INTRODUCTION

Antibiotic use may shorten mechanical ventilation duration and length of stay for patients with bronchiolitis that require intubation. The goals of this study were to describe antibiotic use in previously healthy children with bronchiolitis admitted to the intensive care unit (ICU) for noninvasive respiratory support and to describe associations of early antibiotic use with clinical outcomes.

METHODS

The Pediatric Health Information Systems database was queried for children <2 years of age without significant comorbidities admitted to the ICU for bronchiolitis. Children requiring mechanical ventilation on the first ICU day were excluded. Two groups were analyzed: those patients receiving antibiotics on the first day of their ICU stay (early antibiotics), and those receiving no antibiotics on their first ICU day (no antibiotics). Primary outcome was the length of ICU stay.

RESULTS

A total of 11,029 admissions met criteria, 2522 (22.9%) in the early antibiotic group, and 8507 (77.1%) in the no antibiotic group. The use of early antibiotics varied by center from 10% to 54%. In multivariate analysis, the early antibiotic group had similar ICU length of stay compared to the no antibiotic group (relative risk, RR [95% confidence interval, CI] 1.01 [0.98-1.05]). For patients on noninvasive ventilation, the first ICU day early antibiotics did not impact ICU length of stay (RR [95% CI] 0.97 [0.92-1.02]) or need for intubation (RR [95% CI] 1.11 [0.77-1.58]).

CONCLUSION

Early antibiotic use was common with significant variation between centers. Early antibiotic use was not associated with improved clinical outcomes in children admitted to the ICU for noninvasive respiratory support for bronchiolitis.

Optimal dosing of cefotaxime and desacetylcefotaxime for critically ill paediatric patients. Can we use microsampling?

Objectives

To describe the population pharmacokinetics of cefotaxime and desacetylcefotaxime in critically ill paediatric patients and provide dosing recommendations. We also sought to evaluate the use of capillary microsampling to facilitate data-rich blood sampling.

Methods

Patients were recruited into a pharmacokinetic study, with cefotaxime and desacetylcefotaxime concentrations from plasma samples collected at 0, 0.5, 2, 4 and 6 h used to develop a population pharmacokinetic model using Pmetrics. Monte Carlo dosing simulations were tested using a range of estimated glomerular filtration rates (60, 100, 170 and 200 mL/min/1.73 m²) and body weights (4, 10, 15, 20 and 40 kg) to achieve pharmacokinetic/pharmacodynamic (PK/PD) targets, including 100% ƒT_>MIC with an MIC breakpoint of 1 mg/L.

Results

Thirty-six patients (0.2–12 years) provided 160 conventional samples for inclusion in the model. The pharmacokinetics of cefotaxime and desacetylcefotaxime were best described using one-compartmental model with first-order elimination. The clearance and volume of distribution for cefotaxime were 12.8 L/h and 39.4 L, respectively. The clearance for desacetylcefotaxime was 10.5 L/h. Standard dosing of 50 mg/kg q6h was only able to achieve the PK/PD target of 100% ƒT_>MIC in patients >10 kg and with impaired renal function or patients of 40 kg with normal renal function.

Conclusions

Dosing recommendations support the use of extended or continuous infusion to achieve cefotaxime exposure suitable for bacterial killing in critically ill paediatric patients, including those with severe or deep-seated infection. An external validation of capillary microsampling demonstrated skin-prick sampling can facilitate data-rich pharmacokinetic studies.

Respiratory Pathogen Detection in Pediatric Patients Intubated for Presumed Infection

OBJECTIVES

Respiratory syncytial virus (RSV) in pediatric patients has been associated with low risk of concomitant bacterial infection. However, in children with severe disease, it occurs in 22% to 50% of patients. As viral testing becomes routine, bacterial codetections are increasingly identified in patients with non-RSV viruses. We hypothesized, among patients intubated for respiratory failure secondary to suspected infection, there are similar rates of codetection between RSV and non-RSV viral detections.

METHODS

This retrospective chart review, conducted over a 5-year period, included all patients younger than 2 years who required intubation secondary to respiratory failure from an infectious etiology in a single pediatric emergency department. Patients intubated for noninfectious causes were excluded.

RESULTS

We reviewed 274 patients, of which 181 had positive viral testing. Of these, 48% were RSV-positive and 52% were positive for viruses other than RSV. Codetection of bacteria was found in 76% (n = 65; 95% confidence interval [CI], 66%, 84%) of RSV-positive patients and 66% (n = 63, 95% CI: 57%, 76%) of patients positive with non-RSV viruses. Among patients with negative viral testing, 33% had bacterial growth on lower respiratory culture. Male sex was the only patient-related factor associated with increased odds of codetection (odds ratio [OR], 2.2; 95% CI, 1.08-4.38). The odds of codetection between RSV-positive patients and non-RSV viruses were not significantly different (OR, 1.3; 95% CI, 0.62-2.71).

CONCLUSIONS

Bacterial codetection is common and not associated with anticipated patient-related factors or with a specific virus. These results suggest consideration of empiric antibiotics in infants with respiratory illness requiring intubation.

Risk Factors Associated with Mechanical Ventilation in Critical Bronchiolitis

The American Academy of Pediatrics (AAP) recommends supportive care for the management of bronchiolitis. However, patients admitted to the intensive care unit with severe (critical) bronchiolitis define a unique group with varying needs for both non-invasive and invasive respiratory support. Currently, no guidance exists to help clinicians discern who will progress to invasive mechanical support. Here, we sought to identify key clinical features that distinguish pediatric patients with critical bronchiolitis requiring invasive mechanical ventilation from those that did not. We conducted a retrospective cohort study at a tertiary pediatric medical center. Children ≤2 years old admitted to the pediatric intensive care unit (PICU) from January 2015 to December 2019 with acute bronchiolitis were studied. Patients were divided into non-invasive respiratory support (NRS) and invasive mechanical ventilation (IMV) groups; the IMV group was further subdivided depending on timing of intubation relative to PICU admission. Of the 573 qualifying patients, 133 (23%) required invasive mechanical ventilation. Median age and weight were lower in the IMV group, while incidence of prematurity and pre-existing neurologic or genetic conditions were higher compared to the NRS group. Multi-microbial pneumonias were diagnosed more commonly in the IMV group, in turn associated with higher severity of illness scores, longer PICU lengths of stay, and more antibiotic usage. Within the IMV group, those intubated earlier had a shorter duration of mechanical ventilation and PICU length of stay, associated with lower pathogen load and, in turn, shorter antibiotic duration. Taken together, our data reveal that critically ill patients with bronchiolitis who require mechanical ventilation possess high risk features, including younger age, history of prematurity, neurologic or genetic co-morbidities, and a propensity for multi-microbial infections.

Nasopharyngeal Codetection of H. influenzae and S. pneumoniae and Respiratory Syncytial Virus Disease Outcomes in Children

BACKGROUND

The role of nasopharyngeal bacteria on RSV disease has been underestimated. We measured the frequency and quantitative detection of potentially pathogenic bacteria in the upper respiratory tract of infants with RSV infection over seven respiratory seasons, and their impact on clinical outcomes.

METHODS

Children <2 years old with mild (outpatients; n=115) or severe (inpatients; n=566) RSV infection, and matched healthy controls (n=161) were prospectively enrolled. Nasopharyngeal samples were obtained for RSV, S. pneumoniae, S. aureus, M. catarrhalis, and H. influenzae detection and quantitation by PCR. Multivariable models were constructed to identify variables predictive of severe disease.

RESULTS

S. pneumoniae, H. influenzae, and M. catarrhalis, but not S. aureus, were detected more frequently in RSV-infected children (84%) than healthy controls (46%; p<0.001). Detection of S. pneumoniae and/or H. influenzae was associated with fever, more frequent antibiotic treatment, worse radiologic findings, and higher neutrophil counts (p<0.01). In adjusted analyses S. pneumoniae/H. influenzae co-detection was associated with greater odds (OR; 95% CI) of hospitalization (2.25 [1.07-4.74), higher disease severity scores (1.93 [1.14-3.26]), prolonged oxygen administration (2.23 [1.01-4.91]), and longer hospitalization (2.53 [1.33-4.79]).

CONCLUSIONS

Nasopharyngeal co-detection of S. pneumoniae and H. influenzae in infants with RSV infection is associated with increased disease severity.

Impact of a modification of the clinical practice guide of the American Academy of Pediatrics in the management of severe acute bronchiolitis in a pediatric intensive care unit

OBJECTIVE

To describe the characteristics and evolution of patients with bronchiolitis admitted to a pediatric intensive care unit, and compare treatment pre- and post-publication of the American Academy of Pediatrics clinical practice guide.

DESIGN

A descriptive and observational study was carried out between September 2010 and September 2017.

SETTING

Pediatric intensive care unit.

PATIENTS

Infants under one year of age with severe bronchiolitis.

INTERVENTIONS

Two periods were compared (2010-14 and 2015-17), corresponding to before and after modification of the American Academy of Pediatrics guidelines for the management of bronchiolitis in hospital.

MAIN VARIABLES

Patient sex, age, comorbidities, severity, etiology, administered treatment, bacterial infections, respiratory and inotropic support, length of stay and mortality.

RESULTS

A total of 706 patients were enrolled, of which 414 (58.6%) males, with a median age of 47 days (IQR 25-100.25). Median bronchiolitis severity score (BROSJOD) upon admission: 9 points (IQR 7-11). Respiratory syncytial virus appeared in 460 (65.16%) patients. The first period (2010-14) included 340 patients and the second period (2015-17) 366 patients. More adrenalin and hypertonic saline nebulizations and more corticosteroid treatment were administered in the second period. More noninvasive ventilation and less conventional mechanical ventilation were used, and less inotropic support was needed, with no significant differences. The antibiotherapy rate decreased significantly (P=.003).

CONCLUSIONS

Despite the decrease in antibiotherapy, the use of nebulizations and glucocorticoids in these patients should be limited, as recommended by the guide.

Impact of a modification of the clinical practice guide of the American Academy of Pediatrics in the management of severe acute bronchiolitis in a pediatric intensive care unit

OBJECTIVE

To describe the characteristics and evolution of patients with bronchiolitis admitted to a pediatric intensive care unit, and compare treatment pre- and post-publication of the American Academy of Pediatrics clinical practice guide.

DESIGN

A descriptive and observational study was carried out between September 2010 and September 2017.

SETTING

Pediatric intensive care unit.

PATIENTS

Infants under one year of age with severe bronchiolitis.

INTERVENTIONS

Two periods were compared (2010-14 and 2015-17), corresponding to before and after modification of the American Academy of Pediatrics guidelines for the management of bronchiolitis in hospital.

MAIN VARIABLES

Patient sex, age, comorbidities, severity, etiology, administered treatment, bacterial infections, respiratory and inotropic support, length of stay and mortality.

RESULTS

A total of 706 patients were enrolled, of which 414 (58.6%) males, with a median age of 47 days (IQR 25-100.25). Median bronchiolitis severity score (BROSJOD) upon admission: 9 points (IQR 7-11). Respiratory syncytial virus appeared in 460 (65.16%) patients. The first period (2010-14) included 340 patients and the second period (2015-17) 366 patients. More adrenalin and hypertonic saline nebulizations and more corticosteroid treatment were administered in the second period. More noninvasive ventilation and less conventional mechanical ventilation were used, and less inotropic support was needed, with no significant differences. The antibiotherapy rate decreased significantly (p=0.003).

CONCLUSIONS

Despite the decrease in antibiotherapy, the use of nebulizations and glucocorticoids in these patients should be limited, as recommended by the guide.

Development and validation of a UHPLC-MS/MS method to measure cefotaxime and metabolite desacetylcefotaxime in blood plasma: a pilot study suitable for capillary microsampling in critically ill children

Critical illness has been shown to affect the pharmacokinetics of antibiotics, which can lead to ineffective antibiotic exposure and the potential emergence of resistant bacteria. The lack of studies describing antibiotic pharmacokinetics in critically ill children has led to significant off-label dosing. This is, in part, due to the ethical and physiological challenges of removing frequent, large-volume samples from children. Capillary microsampling facilitates the collection of small volumes of blood samples to conduct clinical pharmacokinetic studies. A sensitive, rapid, and accurate ultra-high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) bioanalytical method to measure cefotaxime and desacetylcefotaxime in 2.8 μL of plasma was developed and validated. Plasma samples were treated with acetonitrile and analytes were separated using a Kinetex C8 (100 × 2.1 mm) column. The chromatographic separation was established using a gradient method, with the mobile phases consisting of acetonitrile and ammonium acetate. An electrospray ionization source interface operated in a positive mode for the multiple reaction monitoring MS/MS analysis of cefotaxime, desacetylcefotaxime, and deuterated cefotaxime (internal standard). The bioanalytical method using microsample volumes met requirements for method validation for both analytes. Cefotaxime had precision within ± 7.3% and accuracy within ± 5% (concentration range of 0.5 to 500 mg/L). Desacetylcefotaxime had precision within ± 9.5% and accuracy within ± 3.5% (concentration range of 0.2 to 10 mg/L). The bioanalytical method was applied for the quantification of cefotaxime and its metabolite to 20 capillary microsamples collected at five time points in one dosing interval from five critically ill children.

Relationship of Viral Detection with Duration of Ventilation in Critically Ill Infants with Lower Respiratory Tract Infection

RATIONALE

Although respiratory virus testing is frequent done for critically ill infants with bronchiolitis, the prognostic value of this testing is unknown for those requiring positive pressure ventilation (PPV).

OBJECTIVES

To determine the differences in PPV utilization according to viral detection and to explore the association between viral detection and duration of PPV in critically ill children with presumed respiratory infection.

METHODS

This is a retrospective cohort study in a quaternary pediatric intensive care unit from February 2014 until February 2017. We evaluated 984 children < 1 year of age who received PPV for presumed respiratory infection without significant congenital heart disease, care limitations, baseline PPV usage, or tracheostomy. Respiratory viruses were identified using a PCR panel. Analyses of duration of PPV according to viral etiology were performed using univariate and multivariable logistic regression and truncated negative binomial regression with calculated mean marginal effect (MME).

RESULTS

Overall, 85 (9%) infants had no viruses identified, 629 (64%) had a single virus detected, most commonly respiratory syncytial virus (RSV) (417, 42%) followed by rhinovirus/enterovirus (RV/EV) (145, 15%), 230 (23%) had 2 viruses detected, and 40 (4%) had three viruses detected. Compared to those with 1 or no virus detected, infants with ≥2 viruses received longer total PPV duration in adjusted analysis [RR:1.4 (95% CI 1.2-1.6); p<0.001, MME=29 hours]. Detection of RV/EV alone, compared to RSV alone, was associated with significantly shorter duration of total PPV [RR:0.7 (95% CI 0.62, 0.87); p=<0.001, MME= -23 hours], noninvasive PPV [RR: 0.7 (95% CI 0.60, 0.85); p<0.001 MME = -15 hours], and invasive PPV [RR 0.7 (95% CI 0.54, 0.83); p<0.001, MME = -54 hours) when adjusted for weight, prematurity, and administration of early antibiotic therapy.

CONCLUSIONS

Identification of viral type and number in severe bronchiolitis is an important predictor of duration of PPV.