The 2018 ESPGHAN guidelines state that only those children receiving long term parenteral nutrition (PN) at high risk to develop acid-base imbalance should have bicarbonate and chloride levels regularly monitored. In June 2022 we introduced regular screening for all patients on home PN (HPN) over concerns that some children may be missed. Our aim was to establish if routine measurement of bicarbonate and chloride status had a clinical impact.

All children attending the intestinal failure (IF) rehabilitation clinic of a large tertiary IF centre who started HPN before December 2022 and had bicarbonate and chloride level checked at least once 3 years before June 2022 till December 2022 were included. 37 patients fulfilled the inclusion criteria (48.6% male, 51.4% female; mean age 11.2 years). Data were collected retrospectively 3 years until June 2022 and prospectively from June to December 2022. Demographics, indication for home PN, bicarbonate and chloride levels, the cause for monitoring and clinical consequences (change in HPN prescription, start of oral supplements, investigations for renal tubular acidosis (RTA) and nephrology consultation) were reviewed.

Indications for HPN Motility disorders (35.1%), short bowel syndrome (29.8%) and intestinal mucosal disorders (35.1%). Out of the patients who started home PN before June 2022, 42.2% had levels monitored 3 years prior to June 2022, the rest started monitoring after June 2022 either due to no monitoring at all before or start of HPN after June 2022. Half of these patients had random checks, the remainder were monitored due to renal disease, and gastrointestinal fluid loss. Only 4 (10.8%) patients had low bicarbonate and 3 (8.1%) high chloride levels. 3 patients were referred for renal review, 3 patients had an increase in acetate in HPN, 2 started oral bicarbonate supplements, 1 had their PN fluids increased (some patients underwent multiple interventions).After June 2022 (24.3%) patients had low bicarbonate and 1 patient had a high chloride. Patients developed acid base imbalance due to, gastrointestinal and renal losses, small intestinal bacterial overgrowth (SIBO). 2 patients received antibiotics for SIBO, 2 patients had increased in PN volume made, 2 patients increased in acetate and 1 reduction in PN chloride done. 2 patients received sodium bicarbonate supplements and the remainder had no change in management as minimal abnormal levels only or known RTA. Regular monitoring made a clinical difference in 9 patient (24.3%) and no differences in 28 (75.7%) Only 3 patients, who were previously not routinely screened, had low bicarbonate after start of regular monitoring.

Our data confirm that regular screening of all children PN has a low diagnostic yield and should be done only in those at risk of developing acid base imbalance.

Reference

1. Hill S, Ksiazyk J, Prell C. ESPGHAN/ESPEN/ESPR/CSPEN guidelines on pediatric parenteral nutrition: Home parenteral nutrition. Clinical Nutrition 2018;37(6):2401–2408.