The CONSEPT trial will investigate whether observation only in patients with a large symptomatic PSP is safe and effective with respect to outcomes that are important to patients, such as the need for invasive treatments and length of hospital stay. Participants will be put into one of two groups by chance.

The observation only group will not have the air drained but will be monitored for a few hours, and if comfortable and stable, discharged from hospital.

The second group will be treated in the usual way by draining the air through a needle or tube. We will collect information to see if patients need to have a subsequent drainage in the first month after having the PSP, and measure symptoms and general health.

We will also monitor whether the PSP recurs within a year.