To Determine the Efficacy of Autologous Blood Patch Therapy in Reducing Air Leak in Secondary Spontaneous Pneumothorax: A Proof-of-Concept Study

The patient must have a chest tube in place and checked to be patent. Approximately 1.5ml/kg of venous blood will be withdrawn from the patient and immediately instilled it into the pleural cavity with aseptic technique via the chest tube already in situ. (There is no standard amount of blood used for ABPT. A small randomized study advocated that the use of 1.5ml/kg as it provided the optimal benefits.) The drain is then flushed with 20ml normal saline to avoid clotting. The tube of the drain is immediately elevated to 60cm above the insertion point of the chest tube at the patient's chest wall for 2 hours. This method allows ongoing evacuation of any air leak while the instilled blood can stay within the pleural cavity. The tube is never clamped at any stage to avoid any risk of tension pneumothorax. The patient was asked to change his position in bed every 10 minutes (supine, right lateral, prone, left lateral, head down and sit upright) during the two-hour period to aid distribution of blood over the visceral pleura. The tube is returned to normal position after two hours and the patient is free to ambulate. Analgesia is freely available for the patient should the need arise, but will not be prescribed routinely as existing data suggest it is uncommon.

Patients will remain under close observation after the instillation for the next 6 hours by experienced respiratory doctors and nurses, in particular for any suggestion of tube blockage or worsening pneumothorax. The tube will be flushed with saline (of an amount similar to the dead space of the tube) if that occurs. In the very unlikely event that the blockage is not correctable, a new chest tube may be placed if deemed clinically necessary. Prophylactic antibiotics will be given at the discretion of the attending clinician. The amount of air leak is measured continuously before and after ABPT using Thopaz system. Patients are free to receive any other therapy (except pleurodesis) during the treatment period.