Relationship between serum citrulline levels and progression to parenteral nutrition independence in children with short bowel syndrome.

OBJECTIVE: Although bowel length is an important prognostic variable used in the management of children with short bowel syndrome (SBS), reliable measurements can be difficult to obtain. Plasma citrulline (CIT) levels have been proposed as surrogate markers for bowel length and function. We sought to evaluate the relationship between CIT and parenteral nutrition (PN) independence in children with SBS.

STUDY DESIGN: A retrospective chart review performed for all patients seen in a multidisciplinary pediatric intestinal rehabilitation clinic with a recorded CIT between January 2005 and December 2007 (n = 27).

RESULTS: Median age at time of CIT determination was 2.4 years. Diagnoses included necrotizing enterocolitis (26%), intestinal atresias (19%), and gastroschisis (22%). Citrulline levels correlated well with bowel length (R = 0.73; P < .0001) and was a strong predictor of PN independence (P Wilcoxon = 0.002; area under the receiver operating characteristic curve = 0.88; 95% confidence interval, 0.75-1.00). The optimal CIT cutoff point distinguishing patients who reached PN independence was 15 micromol/L (sensitivity = 89%; specificity = 78%).

CONCLUSION: Plasma CIT levels are strong predictors of PN independence in children with SBS and correlate well with a patient's recorded bowel length. A cutoff CIT level of 15 micromol/L may serve as a prognostic measure in counseling patients regarding the likelihood of future PN independence.