Chart Review Protocol
Data were collected from the patients’ electronic medical records. Charts were reviewed for demographic information, including age and gender, volume of chest tube output, sirolimus blood level, duration of chest tube placement, other medical and dietary interventions, lymphatic anomaly diagnosis, and co-morbidities. Day 0/Hour 0 was the time of first sirolimus dose. The data from the patients’ charts were recorded in an Excel spreadsheet with all patient identifiers removed.
Chylous effusion was diagnosed by pleural fluid analysis findings consistent with lymphocyte content of >80%, pleural fluid triglyceride level >110 mg/dL and ratio of pleural fluid to serum cholesterol <1.0. The vascular anomalies team was involved in the care of all these patients. Our institutional guidelines for use of Sirolimus are as follows. The starting dose of sirolimus is based on age (0.4mg/m2/dose for patients younger than 6 months and 0.8mg/m2/dose PO or NG/G-tube q12h). Sirolimus trough levels of 8-12 ng/mL are considered therapeutic. A trough level is checked after 72 hours to evaluate for toxicity as some newborns can reach the upper level of the range or even toxic troughs very early. In this case, the sirolimus is held and levels checked until they are back in range and dose adjusted/decreased as needed until reaching goal. If the level is low or within range, it is checked again at 1 week and adjusted at that point. During hospitalization, all patients had sirolimus levels at least weekly. Administration was interrupted during proven or suspected infections and restarted immediately afterwards.