Clinical Outcomes of Antipseudomonal versus Other Antibiotics Among Children with Cystic Fibrosis without Pseudomonas aeruginosa

Update on the diagnosis and management of cystic fibrosis pulmonary exacerbations

Pulmonary exacerbations in people with cystic fibrosis are associated with significant morbidity and reduced quality of life. Pulmonary exacerbation treatment guidelines, published by an expert panel assembled by the Cystic Fibrosis Foundation nearly 15 years ago, were primarily consensus-based as there were several gaps in the evidence base. In particular, limited evidence existed regarding optimal pulmonary exacerbation treatment strategies, including duration of antibiotic therapy, treatment location, antibiotic selection, and the role of systemic corticosteroids. Over the last decade, results from observational studies and large multi-center randomized controlled trials have begun to answer important questions related to pulmonary exacerbation treatment. This review focuses on the diagnosis, etiology, and changing epidemiology of pulmonary exacerbations, and also summarizes the most recent and up-to-date studies describing pulmonary exacerbation treatment. Finally, this review provides consideration for future pulmonary exacerbation research priorities, particularly in the current highly effective modulator therapy era.

Cystic fibrosis year in review 2022

Remarkable medical advancements have been made for people with cystic fibrosis (CF) in recent years, with an abundance of research continuing to be conducted worldwide. With concern for limitations in access to highly effective CFTR modulators, as well as the recent Coronavirus Disease-19 pandemic, there has been a consistent effort to understand and improve CF screening, disease burden, diagnosis, and management. Our aim in this review is to present articles from 2022 with an emphasis on clinically relevant studies. We hope this will serve as a broad overview of the research published in the past year.

Antibiotic Regimen Changes during Cystic Fibrosis Pediatric Pulmonary Exacerbation Treatment

Rationale/Objectives: Antibiotic selection for in-hospital treatment of pulmonary exacerbations (PEx) in people with cystic fibrosis (CF) is typically guided by previous respiratory culture results or past PEx antibiotic treatment. In the absence of clinical improvement during PEx treatment, antibiotics are frequently changed in search of a regimen that better alleviates symptoms and restores lung function. The clinical benefits of changing antibiotics during PEx treatment are largely uncharacterized. Methods: This was a retrospective cohort study using the Cystic Fibrosis Foundation Patient Registry Pediatric Health Information System. PEx were included if they occurred in children with CF from 6 to 21 years old who had been treated with intravenous antibiotics between January 1, 2006, and December 31, 2018. PEx with lengths of stay <5 or >21 days or for which treatment was delivered in an intensive care unit were excluded. An antibiotic change was defined as the addition or subtraction of any intravenous antibiotic between Hospital Day 6 and the day before hospital discharge. Inverse probability of treatment weighting was used to adjust for disease severity and indication bias, which might influence a decision to change antibiotics. Results: In all, 4,099 children with CF contributed 18,745 PEx for analysis, of which 8,169 PEx (43.6%) included a change in intravenous antibiotics on or after Hospital Day 6. The mean change in pre- to post-treatment percent predicted forced expiratory volume in 1 second (ppFEV1) was 11.3 (standard error, 0.21) among events in which an intravenous antibiotic change occurred versus 12.2 (0.18) among PEx without an intravenous antibiotic change (P = 0.001). Similarly, the odds of return to ⩾90% of baseline ppFEV1 were less for PEx with antibiotic changes than for those without changes (odds ratio [OR], 0.89 [95% confidence interval (CI), 0.80-0.98]). The odds of returning to ⩾100% of baseline ppFEV1 did not differ between PEx with versus without antibiotic changes (OR, 0.94 [95% CI, 0.86-1.03]). In addition, PEx treated with intravenous antibiotic changes were associated with higher odds of future PEx (OR, 1.17 [95% CI, 1.12-1.22]). Conclusions: In this retrospective study, changing intravenous antibiotics during PEx treatment in children with CF was common and not associated with improved clinical outcomes.

The Clinical Association between Aspergillus fumigatus and Respiratory Outcomes in Adolescents and Adults with Cystic Fibrosis

Rationale: The clinical significance of Aspergillus fumigatus (Af) detection in the absence of allergic bronchopulmonary aspergillosis in cystic fibrosis (CF) airways remains unclear. Yet, some clinicians initiate antifungal therapy for Af-positive respiratory cultures out of concern for infection in people with CF. Objectives: To determine the association between the presence of Af and respiratory outcomes in individuals with CF. Methods: We conducted a prospective longitudinal cohort study of 206 adults and adolescents (age 14 yr and older) with CF and collected sputum for selective fungus culture. We assessed clinical outcome measurements, including patient-reported outcomes (measured by the Cystic Fibrosis Questionnaire-Revised), spirometry, and number of pulmonary exacerbations (PEx) for a 1-year period. We used mixed-effects linear models to determine the association between positive Af culture results, defined as Af detection in sputum culture at the study visit, with both respiratory domain score and forced expiratory volume in 1 second (FEV1) percent predicted, adjusted for confounders. Mixed-effects Poisson regression models were employed to examine the association between positive Af culture results and PEx events. We explored the association between Af history, defined as Af detection at baseline or within 2 years of enrollment, and respiratory outcomes. Results: Af prevalence was 10.3% (95% confidence interval [CI], 6.8, 15.7) at baseline. Forty-eight (23.3%; 95% CI, 17.7, 29.7) participants had at least one Af-positive culture result during the study period. Positive Af culture result was not associated with lower respiratory domain score. However, Af history was associated with a 6.48-point lower respiratory domain score, reflective of worse respiratory quality of life (95% CI, -11.96, -0.99; P = 0.02). Positive Af culture result was associated with a 2.54% lower FEV1 percent predicted (95% CI, -4.64, -0.44; P = 0.02) and a 1.71-fold increase in severe PEx incidence (95% CI, 1.05, 2.76; P = 0.03). Conclusions: Positive Af culture result was not associated with lower patient-reported, respiratory-related quality of life. Yet, positive Af culture result was associated with both lower FEV1 percent predicted and increased frequency of severe PEx warranting intravenous antibiotics in adolescents and adults with CF. Future studies are required to better understand the direct role of Af in lung disease progression in CF.

The potential of 4D's approach in curbing antimicrobial resistance among bacterial pathogens

INTRODUCTION

Antibiotics are life-saving drugs but irrational/inappropriate use leads to the emergence of antibiotic-resistant bacterial superbugs, making their treatment extremely challenging. Increasing antimicrobial resistance (AMR) among bacterial pathogens is becoming a serious public health concern globally. If ignorance persists, there would not be any antibiotics available to treat even a common bacterial infection in future.

AREA COVERED

This article intends to collate and discuss the potential of 4D's (right Drug, Dose, Duration, and De-escalation of therapy) approach to tackle the emerging problem of AMR. For this, we searched PubMed, Google Scholar, Medline, and clinicaltrials.gov databases primarily using keywords 'optimal antibiotic therapy,' 'antimicrobial resistance,' 'higher versus lower dose antibiotic treatment,' 'shorter versus longer duration antibiotic treatment,' 'de-escalation study', and 'antimicrobial stewardship measures' and based on the findings, form and expressed our opinion.

EXPERT OPINION

More efforts are needed for developing diagnostics for rapid, accurate, point-of-care, and cost-effective pathogen identification and antimicrobial susceptibility testing (AST) to facilitate rational use of antibiotics. Current dosing and duration of therapies also need to be redefined to maximize their impact. Furthermore, de-escalation approaches should be developed and encouraged in the clinic. This altogether will minimize selection pressure on the pathogens and reduce emergence of AMR.

Antibiotics and outcomes of CF pulmonary exacerbations in children infected with MRSA and Pseudomonas aeruginosa

BACKGROUND

Limited data exist to inform antibiotic selection among people with cystic fibrosis (CF) with airway infection by multiple CF-related microorganisms. This study aimed to determine among children with CF co-infected with methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa (Pa) if the addition of anti-MRSA antibiotics to antipseudomonal antibiotic treatment for pulmonary exacerbations (PEx) would be associated with improved clinical outcomes compared with antipseudomonal antibiotics alone.

METHODS

Retrospective cohort study using data from the CF Foundation Patient Registry-Pediatric Health Information System linked dataset. The odds of returning to baseline lung function and having a subsequent PEx requiring intravenous antibiotics were compared between PEx treated with anti-MRSA and antipseudomonal antibiotics and those treated with antipseudomonal antibiotics alone, adjusting for confounding by indication using inverse probability of treatment weighting.

RESULTS

943 children with CF co-infected with MRSA and Pa contributed 2,989 PEx for analysis. Of these, 2,331 (78%) PEx were treated with both anti-MRSA and antipseudomonal antibiotics and 658 (22%) PEx were treated with antipseudomonal antibiotics alone. Compared with PEx treated with antipseudomonal antibiotics alone, the addition of anti-MRSA antibiotics to antipseudomonal antibiotic therapy was not associated with a higher odds of returning to ≥90% or ≥100% of baseline lung function or a lower odds of future PEx requiring intravenous antibiotics.

CONCLUSIONS

Children with CF co-infected with MRSA and Pa may not benefit from the addition of anti-MRSA antibiotics for PEx treatment. Prospective studies evaluating optimal antibiotic selection strategies for PEx treatment are needed to optimize clinical outcomes following PEx treatment.