Continuation Of a Study to Investigate the Effect of Thoracocentesis on Neural Respiratory Drive in Pleural Effusion

This study will involve 124 adult patients who are breathlessness with pleural effusions. They will be recruited from a single UK centre over an 18-month period.

After being informed about the study, all patients giving written informed consent will undergo a baseline assessment when they first come to have their fluid drained. The investigators will record information about them and their disease. The investigators will take measurements of their breathlessness, their breathing muscles, and the electrical activity from the brain to those muscles. These will be taken at the start and end of drainage, as well as 1 day and 7 days after. The investigators will use this information to look for links between the effect of pleural effusions and its removal on the electrical activities of the breathing muscles and patients' breathlessness.

Inclusion criteria

• Age 18 years or above
• Has a unilateral pleural effusion AND

• require thoracocentesis OR
• chest drain insertion (main study only) OR
• has an IPC in situ (main study only)

Exclusion criteria

• Inability to consent
• Any contraindications to the proposed pleural procedure
• Haemodynamic or clinical instability that precludes from the safe completion of required pre-procedural measurements
• Inability to identify surface landmarks for surface EMG electrode placement
• Past medical history of diaphragmatic paralysis (diaphragm sub study only)