Fibrinolytic therapy — The use of fibrinolytic drugs to lyse the fibrinous strands in loculated parapneumonic effusions has been described in adults and children. These drugs include urokinase, alteplase (tPA), or streptokinase

Efficacy – The evidence supporting fibrinolysis as a component of medical therapy for complicated parapneumonic effusion comes from randomized trials and meta-analyses comparing various fibrinolytic therapies with normal saline, and weakly favors fibrinolytic therapy

Choice of agent – No controlled studies are available to determine whether any one of the fibrinolytic agents is more effective than the others. The choice of agent depends upon availability, with urokinase being preferred if it is available, followed by alteplase (tPA) and streptokinase. Addition of the mucolytic agent deoxyribonuclease (DNase; eg, dornase alfa) to the fibrinolytic regimen has no benefit in length of hospital stay or other outcomes, based on a randomized trial in children [38], although it appears to enhance treatment in adults

Only urokinase has been studied in a placebo-controlled fashion in children and thus is recommended by the BTS [2]. In North America, urokinase is no longer available, so alteplase is usually used. This approach is supported by a retrospective case series showing similar outcomes and increased thoracostomy tube drainage with alteplase compared with urokinase [40]. Streptokinase is generally considered a third-line choice because of limited efficacy in one large trial and reports of occasional allergic reactions

Technique and dose – Fibrinolytic therapy is administered by instilling the drug through the chest tube, or via irrigation at the time of thoracoscopy. In most cases, we administer fibrinolytic therapy through a pigtail catheter, inserted under ultrasound guidance using light sedation. The treatment may cause discomfort, and adequate sedation and or analgesia need to be provided

Contraindications – Fibrinolytic therapy should not be performed in patients who have bronchopleural fistula or chest tubes that are bubbling (suggestive of an air leak), since clamping of the chest tube in such a patient could result in tension pneumothorax. In addition, chest tubes that are clamped must be immediately unclamped if the child has any signs of clinical deterioration (eg, breathlessness, chest pain).

streptokinase dosing:

25,000 units in 50-100 mL of saline intrapleurally via chest tube with clamping for 4 hours

maximum total dose of 250,000 units per instillation