Evolution of dry powder inhaled colistimethate sodium (Colobreathe®) in a large adult cystic fibrosis centre

Objectives: Colobreathe® is a dry powder formulation of colistimethate sodium developed to reduce treatment burden for people with cystic fibrosis. In our centre initial experience revealed 45% discontinued this therapy within 12 months, of which 83% were due to tolerance or device issues. Capsuleswere reformulated in 2017 to address some of these issues. We aimed to assess the prescription rates of Colobreathe® over 3 time periods to assess whether prescription practices and tolerance changed. Methods: A retrospective review of antibiotic challenges in the one-year periods from Dec 2013, 2016 and 2020 was conducted. Key end points included tolerance of test dose and continued use at 1 and 3 months. The proportion of antibiotic challenges that were Colobreathe® at each time point was compared. Results: Therewas a significant difference in the proportion of all antibiotic challenges whichwere for Colobreathe® across the 3 periods (2013–65/186 (35%), 2016–8/136 (6%), 2020–22/55 (40%), p < 0.001). The majority of patients at all 3 time points had previously nebulised colistimethate sodium (98%, 88% and 100%, respectively). All patients had a successful test dose during each time period. Therewas no difference in the proportion of patients who commenced long-term prescription following a 1-month review at the 3 time periods (75%, 75% and 73% respectively, p = 0.97). Of those who received a long-term prescription, continuation rates were similar at 3 months (82%, 100% and 93%, respectively). Conclusions: There was a marked reduction in inhaled antibiotic challenges in 2020, likely due to COVID. There was a significant change in prescription of Colobreathe® over the 3 time frames. Colobreathe®waswell tolerated at initial challenge and continuation rates after a month appear to be consistent. A number of factors likely influenced prescription practices, including early experience and potentially changing airway physiology following CFTR modulation introduction.

Microbiological surveillance in cystic fibrosis – an emerging multifactorial challenge

Objectives: Accurate identification of airway pathogens with appropriate eradication and suppressive therapies is associated with improved health outcomes in cystic fibrosis (CF). From 2020, 2 key factors may have influenced the ability to carry out this monitoring effectively;1. the COVID- 19 pandemic accelerated a transition to ‘virtual’ clinic visits and 2. the introduction of ELX/TEZ/IVA. Methods:We retrospectively analysed out-patient clinic attendance in the month of November for the years 2017–2021 and microbiological samples received from adults with CF in the regional microbiology department. Results: The total number of microbiological samples reduced in 2020 and 2021 (Table 1). In 2017, 211 samples were generated from 261 clinic visits (80.8%). For subsequent years this was 80.0%, 71.0%, 51.2% and 72.2%, respectively. The proportion of cough swabs significantly increased in 2021, (p < 0.001). In 20216 postal sampleswere provided, indicating that yield of a sample from a virtual appointment was at most 8.3%. Table 1. Overview of microbiological samples and clinic visits November 2017–2021 (Table Presented)Conclusions: There has been a marked reduction in microbiological samples in the years 2020 and 2021 despite relative preservation of total clinic appointments. This appears to be partly due to an increase in virtual clinic attendance without adequate remote sampling. The disproportionate increase in cough swabs in 2021 can be attributed to ELX/TEZ/IVA availability resulting in decreased sputum burden. This work identifies challenges in monitoring patients established on highly effective modulator therapy in new clinic models

A retrospective audit of home-based spirometry quality in a large UK adult cystic fibrosis centre

Objectives: Spirometry measurement is the gold standard for assessing disease severity in cystic fibrosis (CF). Poor-quality spirometry tests can result in inaccurate measurement of FEV1 and FVC. Manchester Adult CF Centre has transformed from hospital to home-based spirometry testing during COVID-19. Unlike hospital-based spirometry, home-based spirometry relies entirely on the subject to obtain good quality spirometry. Therefore, we sought to ascertain the quality of home-based spirometry and the test errors in our patients. Methods: A convenience sample of adults with CF attending Manchester Adult CF Centre were provided with a NuvoAir home-based spirometer to perform routine lung function between March–October 2020. NuvoAir respiratory platform consists of a mobile phone application, Bluetooth spirometer and an online results portal. The spirometer also provides feedback to patients’ spirometry quality. Initial patient set-up was performed in-hospital or virtually with a member of the CF clinical team. All patient sessions were included irrespective of quality of spirometry test session. Acceptability and repeatability criteria were applied as per NuvoAir software in line with ATS/ERS guidelines, along with assigning a quality grading A–Faccording to ATS/ERS standardised pulmonary function report criteria at time of testing. Results: 66 CF patients (32 female) mean age 31.3 (18–55) performed 343 spirometry sessions totaling 1,041 individual spirometry tests with a NuvoAir device were graded as follows: Grade A = 30.3%, Grade B = 36.2%, Grade C = 3.5%, Grade D = 2.6%, Grade E = 16.6%, Grade F = 10.8%. Further analysis of all 1,041 tests for common errors indicated BX – Back extrapolation 2%, TP- Time to Peak (slow start) 14.6%, CO – Cough 1.4%, ET – Early termination 0.5%, CE – Cessation or glottic closure 12.9%. Overall, general tests A–C considered usable was 70%. Conclusion: The results show good-quality standards can be achieved through home-based spirometry.