Cystic fibrosis: pulmonary and multidisciplinary management — branching viva

Opening

Examiner: A 9-year-old with cystic fibrosis attends routine clinic. She is at her personal best FEV1 and growing well, but her cough swab has grown Pseudomonas for the first time. How do you approach her overall pulmonary care and this new result? ^[11]

Candidate: I would frame her care around four pillars delivered daily: airway clearance physiotherapy, mucoactive nebulisers such as dornase alfa and hypertonic saline, an anti-infective strategy, and CFTR modulator therapy, all coordinated by the multidisciplinary team with nutrition. The new result is a first Pseudomonas isolate, and my priority is immediate eradication rather than observation, because preventing chronic Pseudomonas infection protects her long-term lung function. ^{[11] [7]}

Branch 1 — the first Pseudomonas isolate

Examiner: Why not simply repeat the culture and watch, since she is well? ^[11]

Candidate: Because a first Pseudomonas isolate is a window of opportunity. Early eradication with a regimen such as inhaled tobramycin, with or without oral ciprofloxacin, clears the organism in most children and delays or prevents chronic infection, which is one of the strongest predictors of accelerated lung decline. Watching risks letting a treatable early infection become an established biofilm that we can only suppress, not clear. ^{[11] [7]}

Examiner (probe): How do the mucoactive nebulisers help, and how do they differ? ^[4]

Candidate: Dornase alfa is recombinant human DNase that cleaves the extracellular DNA released by neutrophils in cystic fibrosis sputum, thinning the mucus and improving lung function and exacerbation rates. Hypertonic saline works by a different mechanism, osmotically drawing water back onto the dehydrated airway surface to improve clearance. They are complementary and both given regularly, not only when unwell. ^{[4] [7]}