Pleural effusion requiring drainage in congenital diaphragmatic hernia: incidence, aetiology and treatment.

In congenital diaphragmatic hernia (CDH), chest tube insertion at repair could determine rapid overexpansion of hypoplastic lungs, increasing the risk of pneumothorax. Therefore, in our institution no drainage tube at CDH repair was inserted after 1997. Afterwards several patients needed chest drainage for cardiopulmonary distress due to pleural effusion (PE) during the postoperative course. The aims of this study are to establish the incidence of PE requiring drainage for cardiopulmonary distress during postoperative course in CDH and to assess its eventual increase in patients with patch repair. Furthermore, the aetiology and treatment of PE are highlighted. Records of high-risk CDH operated on from 1998 to 2004 were reviewed. No chest tube was inserted at repair. Drainage was accomplished postoperatively if a cardiopulmonary distress due to PE occurred. Groups with and without patch were compared on gender, gestational age, birth weight, side of hernia, PE, hernial sac, central venous line and venous thrombosis, using the chi(2) and Student's t tests. Overall mortality rate was recorded. Out of 76 patients, 23 (30%) required patch repair. The PE occurred in 22 out of 76 patients, and in 68% of cases a chylothorax resulted. Birth weight was significantly lower, and the PE rate was significantly higher in patients with patch. Pleural drainage yielded improvement of ventilatory and respiratory parameters in all cases. Overall mortality rate was 16 and 23% in patients that required chest drain. The incidence of PE was 30% in CDH and significantly higher in patients with patch. The increased mortality rate in patients with PE causing cardiopulmonary distress warrants chest tube drainage before instability occurs.