Milky appearance of peritoneal fluid in a neonate on peritoneal dialysis due to end-stage renal disease: Answers

The milky appearance of the peritoneal fluid is likely due to chyle leak.

Diagnosis is confirmed by an elevated triglyceride level in the peritoneal fluid of more than 110 mg/dL. However, it is important to rule out peritonitis in this setting of a change in the clarity of the peritoneal fluid. The triglyceride level in the peritoneal fluid was 184 mg/dL (elevated), while that in the serum was 51 mg/dL (normal). Clinically, the infant had a healthy appearance with no outward signs of infection. Peritonitis was ruled out based on the low white blood cell count in the peritoneal fluid (2/mm³).

First-line therapy should be dietary modification with a change to a medium-chain triglyceride (MCT)-based formula. Once the diagnosis had been established, we promptly changed the diet of the infant from Diet 1 to Diet 2 (Table 1) at 120 mL/kg/day to reduce the intake of long-chain triglycerides (LCTs) while awaiting a specialized formula. Within 12 h (after 4 feeds of Diet 2), the milky appearance of the peritoneal fluid resolved, and the fluid had became clear and colorless (Fig. 1). Within 24 h, the triglyceride level of the peritoneal fluid returned to normal (<10 mg/dL). After 24 h on Diet 2, we introduced Diet 3 (Table 1) with Enfaport, which was given as bolus feeds at 120 mL/kg/day. Enfaport contains 84% of fat from MCTs, while also providing a small amount of LCTs to prevent essential fatty acid deficiencies. The infant continued on Diet 3 for a total of 9 days. The triglyceride level of the peritoneal fluid was measured daily and remained normal (<10 mg/dL); the peritoneal fluid remained clear. On the tenth day of Diet 3, we started the infant on a slow transition back to Diet 1 by increasing the number of feeds per day of Diet 1 and simultaneously reducing the number of feeds of Diet 3 (Table 2). The peritoneal fluid remained clear with the reintroduction of Diet 1, but a slight increase in triglyceride level was initially noted in the peritoneal fluid (68 mg/dL). Over the next 8 days (by day of life 52) the patient was successfully transitioned to Diet 1. There was no recurrence of chyloperitoneum.

No, with dietary modifications peritoneal dialysis (PD) can be continued. The infant continued on PD on the Gesco PD system with the introduction of dietary modification. Triglyceride levels in the peritoneal fluid were monitored at regular intervals.