Following thoracic surgery, pleural effusion in pleural cavity requires post-operative drainage, most often for few days (2 to 5 days) until fluid quantity is lower than 50 mL / 24h.~Pleural effusion may cause pulmonary congestion, atelectasis, hypoventilation, lower efficacy of diaphragmatic curse, lower pulmonary reexpansion and vicious attitude.~Respiratory physiotherapy in such situations has different aims : pulmonary decongestion and reexpansion, aid for drainage and pleural fluid reduction, avoiding complications and preventing vicious attitudes.~These aims are learned in Physiotherapy formation institutes. The forced expiration technic in ipsilateral decubitus is justified by pleural physiology and is used after pediatric surgery without any scientific evidence regarding his efficacy Using pulmonary physiotherapy after pulmonary, mediastinal or pleural surgery for children is not systematic and depends on prescriber without any professional recommendation.~Actually no scientific evidence regarding technical or postural indicates improvement of effusion drainage.~It seems to be necessary to validate efficiency of such a technic and evaluate its consequences on post-operative pain. Furthermore, this pleural drainage impacts directly the duration of hospitalization and paramedical workload
Following thoracic surgery, pleural effusion in pleural cavity requires post-operative drainage.~Pleural effusion is responsible for pulmonary congestion, atelectasis, hypoventilation, lower efficacy of diaphragmatic curse, lower pulmonary reexpansion and vicious attitude. These complications could be avoided by respiratory physiotherapy.~Forced expiration technic in ipsilateral decubitus is one of these technics but has never been proved better than other technics regarding its efficiency.~The aim of the study is to compare the impact of such a technic on post operative thoracic drainage after pulmonary, pleural or mediastinal pediatric surgery.