A 1.4 kg ex-preterm infant recovering from staphylococcal sepsis/ pneumonia developed increasing respiratory distress. Chest X-ray showed large bilateral pneumatocoeles, R>L (figure 1A). Mean airway pressure on continuous positive airway pressure was increased (8 cm H 2 O) and the baby positioned right-side-up aiming to expand the atelectatic right lung. Subsequent chest X-ray and chest CT showed an enlarging multiseptated right-sided pneumatocoele, producing midline shift (figure 1B, C).A multidisciplinary (surgery/respiratory/ENT) discussion of treatment options debated pigtail catheter placement 1 but considered this inappropriate given the multiple septations and likelihood of persistent air leak. Selective intubation of the left main bronchus 2 or ballooning of the right main bronchus was considered technically challenging and inappropriate given the large left-sided pneumatocoele. Surgical lobectomy was deemed too invasive. 2 The hypothesis that high mean airway pressure drives accumulation of pneumatocoeles 3 guided our approach of lowered continuous positive airway pressure (weaning from 5 cm H 2 O to 3 cm H 2 O over 7 days) and dexamethasone administration (0.25 mg/kg/day for 3 days, weaning over 6 days) to reduce inflammation. 1 Within 2 weeks, the right-sided pneumatocoele had resolved; 6 months later both lungs were normal ( figure 1D, E). REFERENCES 1 Arias-Camison JM, Kurtis PS, Feld RS, et al. Decompensation of multiple pneumatoceles in a premature infant by percutaneous catheter placement.