Background

Primary Spontaneous Pneumothorax (PSP) refers to collapse of the lung (with air in the chest) in the absence of trauma in patients with no underlying lung disease. This causes pain and breathlessness; often requiring admission to hospital and chest drain insertion (median stay 4-5 days). There is no good evidence to predict which patients will resolve and who will fail treatment (defined as ongoing PSP at Day 4). This study aimed to determine whether clinical factors such as duration and severity of symptoms, and PSP size are associated treatment failure.

Methods

This study used prospectively collected data from the 236 patients from RAMPP randomised trial [Hallifax et al, Lancet 2020;396:39-49]. Clinical data were collected from hospital records and daily patient questionnaires.

Results

Patients had a median breathlessness score of 40.8/100 and pain score of 31.3/100 at admission. 63/236 (26.7%) failed treatment. On average, symptoms started 1 day before admission. 96/236 patients (40.7%) presented on the day symptoms started: their risk of treatment failure was higher (33.7%) than patients presenting >=1 day after symptoms began (22.8%). Interestingly, a low baseline breathlessness or pain score was also associated with greater risk of failure (34.6% and 31.1%, respectively, vs 21.1% and 24.0% for high score). Patients with larger PSP (>=4cm at the hilum on chest x-ray) had longer treatment duration (median 3 vs 1 days if <4cm).

Conclusion

Risk of treatment failure was greater in PSP patients presenting on the day symptoms began, and unexpectedly, in those patients with lower pain and breathlessness scores. Further work is required to generate a tool to predict treatment failure.