Pulmonary function in rats dying from long‐term parenteral nutrition

Energy-enhanced parenteral nutrition and neurodevelopment of preterm newborns: A cohort study

OBJECTIVES

Preterm births are at higher risk for neurodevelopment (NDV) disabilities. To limit long-term consequences, guidelines recommend aggressive parenteral nutrition (PN) soon after birth. The aim of this study was to examine the effects of energy-enhanced PN in the first week of life on long-term NDV in preterm neonates.

METHODS

We compared two cohorts of newborns (group A: energy-enhanced PN and group B: energy-standard PN) with different energy intake in the first 7 d of life (DoL) given by PN with the same protein amount, to study the influences of an energy-enhanced PN on NDV at 24 mo of life evaluated with the Bayley Scale of Infant Development-III edition.

RESULTS

We analyzed 51 newborns (A: n = 24 versus B: n = 27). The two cohorts were similar in baseline characteristics (gestational age group A 29 wk, 95% confidence interval [CI], 28-30 wk versus group B 29 wk, 95% CI, 28-30 wk; birth weight A: 1214 g, 95% CI, 1062-1365 g versus B 1215 g, 95% CI, 1068-1363 g; boys A 62.5% versus B 55.6%). Infants in cohort B showed significantly (P < 0.05) better gross motor, total scaled, and total composite motor scores (A: 8 (1) versus B 9 (2); A 17 (4) versus B 19 (5); A 91 (12) versus B 97 (15); respectively). Cohort A showed a higher percentage of infants with delayed socioemotional competence (A 30.4% versus B 7.7%, P < 0.05). No differences were found in growth parameters at 24 mo of life. Linear regression analysis showed that socioemotional competence and motor score were negatively associated with energy intake of the first 7 DoL given by PN.

CONCLUSIONS

A more aggressive PN strategy results in lower motor score and socioemotional competence performance at 24 mo of life. More caution might be advocated for an energy-enhanced PN protocol, particularly in neonates with lower birth weight, for long-term NDV in preterm neonates.

Prevention of catheter thrombosis increases survival, but does not modify lung injury in rats receiving long-term parenteral nutrition

It has previously been shown that rats receiving total parenteral nutrition (TPN) or each component of TPN die within 40 days of treatment. Central catheter thrombosis and lung injury were constant findings. The aim of the present study was to examine the impact of central thrombosis on lung injury and survival in rats receiving long-term parenteral nutrition. In the first part of the study TPN was infused via the jugular vein and incidence of central venous thrombosis and rate of survival were recorded. Addition of low molecular weight heparin (LMWH) reduced central thrombosis from 6 out of 7 animals to 2 out of 7 animals (p=0.027) and increased survival from 17.1+/-4.5 days to 32.4+/-4.9 days (p=0.04). In the second part of the study four infusion groups were established. Group 1 (controls) received saline 100 mL/kg/day via the jugular vein (n=6). Group 2 received Intralipid 40 mL/kg/day via the jugular vein (n = 7). Group 3 received Intralipid 40 mL/kg/day via the portal vein (n = 7). Group 4 received Intralipid 40 mL/kg/day with added LMWH 70 U/kg/day (n = 7). Lung injury and occurrence of central thrombosis were investigated. Lung injury was assessed by measuring pulmonary arterial pressure (Ppa), clearance of serotonin by the vascular endothelium and the capillary filtration coefficient (CFC). Either infusion via the portal vein or the addition of LMWH to the infusion via the jugular vein prevented central thrombus formation, but the lung injury was not modified by this method compared with infusing Intralipid via the jugular vein without LMWH. In conclusion, central thrombus formation contributes to death in rats receiving parenteral nutrition. The mechanism of the injurious effect of central thrombosis remains unknown, but central thrombus formation seems not to increase lung injury caused by Intralipid.