This clinical trial focused on patients referred to the cardiac surgery clinic of Imam Reza Hospital in Mashhad 2023 who were diagnosed with unilateral or bilateral pleural effusion resistant to conservative management.

Allogenic platelet-rich plasma with fibrin glue (PRP-FG) was derived from blood obtained from a blood bank. Peripheral blood (400 ml) was collected from a donor with a matching ABO blood type, and rigorous viral safety tests were conducted. Concentrated PRP (10 ml) was obtained by subjecting the sample to centrifugation at 4000 g for 15 min to separate the plasma from the sedimented platelets.

Fibrinogen was extracted from the separated plasma using cryoprecipitation. After freezing at -70°C followed by thawing at 4°C, fibrinogen concentrate (20 ml) was prepared by centrifugation at 6500 × g for 5 min. The concentrated PRP was combined with fibrinogen (30 ml).

Thrombin was generated from the plasma isolated during the second centrifugation step. The ionic strength and pH were adjusted to precipitate prothrombin. The resulting precipitate was separated by centrifugation and dissolved in a calcium ion solution, resulting in a final volume of 5 ml of thrombin solution.

Continuous: Air leak is Present throughout the respiratory cycle Inspiratory: Present during the inspiration phase of the respiratory cycle.

Expiratory: Present only during the expiratory phase of the respiratory cycle Forced expiration: Present only when the patient coughs or forces exhalation.

The percent area on chest x-ray is almost completely transparent to radiation.

Duration of the patient's stay in hospital, assessed up to 40 weeks

The treatment was successful if the bubbling was stopped and lung expansion was done.

The bubbling was not stopped, lung expansion was not done and the patient was expired

PRP-FG (5-7 ml/ kg) was injected into the pleural space through the chest tube.