The Long-term Impact of Parenteral Nutrition on Growth in surgical infants
Purpose: Although surgical infants on parenteral nutrition (PN) are known to exhibit poor growth, it is not known whether catch-up growth occurs following establishment of full enteral feeds. Our aim was to determine the pattern of growth of surgical infants both during PN and following attainment of full enteral feeds.
Methods: After IRB approval, we retrospectively studied a cohort of 38 surgical infants <3 months of age who had received PN between September 2002 and March 2005 and went on to achieve full enteral feeds. Case notes, including outpatient notes, were reviewed and the following data collected; date of birth, gestational age, sex and weights at birth and prior, during and after PN including the date of measurement. Weight Z-scores were calculated for each measurement, and analysed using paired t-tests and multi-level regression modelling. Data are shown as mean+/-SEM.
Results: Surgical infants were slightly under 50th centile at commencement of PN (Z-score -0.45+/-0.18). Whilst receiving PN, they lost 0.10+/-0.01 Z-scores per week of PN (p<0.001; Figure) and had a weight Z-score of -1.4+/-0.21 at the end of PN. After establishment of full enteral feeds, infants continued to grow poorly, with a further loss of weight Z-score. This poor growth continued for about 3-6 months following establishment of full enteral feeding, after which catch-up growth occurred (Figure) so that on average, 0.19+/-0.03 Z-scores were gained per year after full enteral feeds were reached (p<0.001). Weight Z-score at last follow-up (-0.7+/-0.3) was significantly greater than that at end of PN (p=0.013).
Conclusion: Even after reaching full enteral feeding, surgical infants continue to grow poorly. Although tolerance to full enteral feeds is achieved, we speculate that the intestine may require further time to adapt and reach full absorptive capacity. Catch-up growth eventually takes place, but there may be long-term adverse effects of an extended period of sub-optimal growth, for example on lean body mass or cardiovascular risk factors.