Autologous Blood Patch Therapy Clinical Trial
Official title:
To Determine the Efficacy of Autologous Blood Patch Therapy in Reducing Air Leak in Secondary Spontaneous Pneumothorax: A Proof-of-Concept Study
This is a prospective clinical trial with each patient serving as his/her own control.
Patients will be recruited in three different Hong Kong hospital. All patients at the
recruitment centers with ongoing air leak after ≥ 3 days from the initial diagnosis of SSP
will be approached by site investigators. Patient consented to enter the study will have
their rate of air leak measured on day 3 (or after if enrolled later than day 3) byreplacing
the conventional chest drain system with the digital chest drainage device (Thopaz).
Autologous blood patch will be instilled if the patient still has persistent air leak on day
5 of chest drain insertion ( or 48 hours of electronic chest drain measurement of airleak).
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of venous blood will be withdrawn from the patient and immediately instilled it into the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.
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