Conclusions
Intrapleural injection of OK-432 was useful for treating a low-birth-weight infant with trisomy 18 who developed refractory chylothorax after thoracic surgery. This approach has been shown to effectively increase the concentration of OK-432 in cases with a large amount of pleural effusion. However, there are some side effects, including a fever and respiratory disorder. Given the small number of cases involving pleurodesis with OK-432, the accumulation of cases is difficult at present. Therefore, reports concerning the usefulness of OK-432 for high-risk patients with chromosomal anomalies, like our case, are essential to prove its effectiveness and highlight its side effects and safety of use.