Re-examining baseline lung function recovery following IV-treated pulmonary exacerbations

Treatment of small as well as large declines in lung function enhances recovery to baseline in people with CF

BACKGROUND

The benefit of antibiotic treatment of acute drops in FEV1 percent predicted (FEV1pp) has been clearly established, but data from the early 2000s showed inconsistent treatment. Further, there is no empirical evidence for what magnitude of drop is clinically significant.

METHODS

We used data from the CF Foundation Patient Registry (CFFPR) from 2016 to 2019 to determine the association between treatment (any IV antibiotics, only oral or newly prescribed inhaled antibiotics, or no antibiotic therapy) following a decline of ≥5% from baseline FEV1pp and return to 100% baseline FEV1pp days using multivariable logistic regression including an interaction between the magnitude of decline and treatment category.

RESULTS

Overall, 16,495 PWCF had a decline: 16.5% were treated with IV antibiotics, 25.0% non-IV antibiotics, and 58.5% received no antibiotics. Antibiotic treatment was more likely for those with lower lung function, history of a positive PA culture, older age and larger FEV1 decline (p < 0.001). Treatment with IV antibiotics or oral/inhaled antibiotics was associated with a higher odds of recovery to baseline compared to no treatment across all levels of decline, including declines of 5%-10%.

CONCLUSIONS

A large proportion of acute drops in FEV1pp continue to be untreated, especially in younger patients and those with higher baseline lung function. Acute drops as small as 5% predicted are less likely to be recovered if antibiotic treatment is not prescribed. These findings suggest the need for more aggressive antimicrobial treatment of acute drops in FEV1, including those of a magnitude previously believed to be associated with self-recovery.

Predicting return of lung function after a pulmonary exacerbation using the cystic fibrosis respiratory symptom diary-chronic respiratory infection symptom scale

BACKGROUND

Pulmonary exacerbations (PExs) in people with cystic fibrosis (PwCF) are associated with increased healthcare costs, decreased quality of life and the risk for permanent decline in lung function. Symptom burden, the continuous physiological and emotional symptoms on an individual related to their disease, may be a useful tool for monitoring PwCF during a PEx, and identifying individuals at high risk for permanent decline in lung function. The purpose of this study was to investigate if the degree of symptom burden severity, measured by the Cystic Fibrosis Respiratory Symptom Diary (CFRSD)- Chronic Respiratory Infection Symptom Scale (CRISS), at the onset of a PEx can predict failure to return to baseline lung function by the end of treatment.

METHODS

A secondary analysis of a longitudinal, observational study (N = 56) was conducted. Data was collected at four time points: year-prior-to-enrollment annual appointment, termed "baseline", day 1 of PEx diagnosis, termed "Visit 1", day 10-21 of PEx diagnosis, termed "Visit 2" and two-weeks post-hospitalization, termed "Visit 3". A linear regression model was performed to analyze the research question.

RESULTS

A regression model predicted that recovery of lung function decreased by 0.2 points for every increase in CRISS points, indicating that participants with a CRISS score greater than 48.3 were at 14% greater risk of not recovering to baseline lung function by Visit 2, than people with lower scores.

CONCLUSION

Monitoring CRISS scores in PwCF is an efficient, reliable, non-invasive way to determine a person's status at the beginning of a PEx. The results presented in this paper support the usefulness of studying symptoms in the context of PEx in PwCF.

A randomised trial of oral prednisone for cystic fibrosis pulmonary exacerbation treatment

BACKGROUND

Elevated markers of systemic and pulmonary inflammation are associated with failure to recover lung function following pulmonary exacerbations in people with cystic fibrosis (pwCF). Our aim was to determine whether adjuvant oral prednisone treatment would improve recovery of forced expiratory volume in 1 s (FEV1) % pred in CF pulmonary exacerbations not responding to antibiotic therapy.

METHODS

This was a randomised, double-blind, placebo-controlled trial in pwCF treated with intravenous antibiotics for a pulmonary exacerbation. At day 7, those who had not returned to >90% baseline FEV1 % pred were randomised to adjuvant prednisone 1 mg·kg-1 twice daily (maximum 60 mg·day-1) or placebo for 7 days. The primary outcome was the difference in proportion of subjects who recovered >90% baseline FEV1 % pred at day 14 of i.v. antibiotic therapy.

RESULTS

173 subjects were enrolled, with 76 randomised. 50% of subjects in the prednisone group recovered baseline FEV1 on day 14 compared with 39% of subjects in the placebo group (difference of 11%, 95% CI -11-34%; p=0.34). The mean±sd change in FEV1 % pred from day 7 to day 14 was 6.8±8.8% predicted in the prednisone group and 4.6±6.9% predicted in the placebo group (mean difference 2.2% predicted, 95% CI -1.5-5.9%; p=0.24). Time to subsequent exacerbation was not prolonged in prednisone-treated subjects (hazard ratio 0.83, 95% CI 0.45-1.53; p=0.54).

CONCLUSIONS

This study failed to detect a difference in FEV1 % pred recovery between adjuvant oral prednisone and placebo treatment in pwCF not responding at day 7 of i.v. antibiotic therapy for pulmonary exacerbations.

Factors influencing treatment response of pulmonary exacerbation in children with cystic fibrosis

BACKGROUND

Pulmonary exacerbations in cystic fibrosis (CF) significantly impact morbidity and mortality. This study aimed to assess treatment response rates and identify contributing factors towards treatment response.

METHODS

In this single-center, retrospective, longitudinal study spanning four years, we analyzed all pulmonary exacerbation admissions. We compared lung function at baseline, admission, end of treatment, and 6-week follow-up. Treatment response was defined as ≥95% recovery of baseline FEV1%.

RESULTS

There were 78 children who required a total of 184 admissions. The mean duration of treatment was 14.9±2.9 days. FEV1% returned to 95% of baseline in 59% following treatment. The magnitude of the decline in lung function on admission in children who did not respond to treatment was 21.7±15.2% while the decline in children who responded to treatment was 8.3±9.4%, P<0.001. Children who experienced a decline in FEV1% greater than 40% exhibited an 80% reduced likelihood of returning to their baseline values (OR -0.8, 95% CI -0.988; -0.612). Similarly, those with FEV1% reductions in the ranges of 30-39% (OR -0.63, 95% CI -0.821; -0.439), 20-29% (OR -0.52, 95% CI -0.657; -0.383), and 10-19% (OR -0.239, 95% CI -0.33; -0.148) showed progressively lower odds of returning to baseline. Fourty-eight children required readmission within 7.7±5.4 months, children who responded to treatment had a longer time taken to readmission (8.9±6.4 months) versus children who did not respond to treatment (6.4±3.5 months), (OR: -0.20, 95% CI -0.355; -0.048).

CONCLUSIONS

A greater decline in lung function on admission and readmission within 6 months of the initial admission predicts non-response to treatment. This highlights the importance of re-evaluating follow-up strategies following discharge.

Factors associated with lung function response with oral antibiotic treatment of pulmonary exacerbations in cystic fibrosis

Pulmonary exacerbations treated with oral antibiotics (oPEx) have a significant effect on lung function decline in people with cystic fibrosis (CF). However, factors associated with lung function response with oPExs are not well defined. We performed a retrospective cohort study of pediatric and adult patients with CF followed in the Toronto CF Database. Lung function response was measured both as the change in forced expiratory volume in 1 second (FEV1) from Day 0 of antibiotic therapy to end of treatment as well as from baseline to end of treatment. Drop from baseline to Day 0 FEV1 was strongly associated with lung function response (p<0.001). Greater FEV1 improvements were associated with longer antibiotic treatment durations. Older, female patients had less improvements in FEV1 at end of treatment compared to younger, male patients.