Parenteral Nutrition: “The Scar Remains”

A recent study (KM Gura et al. J Pediatr 2021; 230: 46-54. Fish Oil Emulsion Reduces Liver Injury and Liver Transplantation in Children with Intestinal Failure-Associated Liver Disease: A Multicenter Integrated Study) provides multicenter data comparing fish oil emulsion (FOLE) (Omegaven) with a historical control of soybean emulsion (SOLE) (Intralipid). The FOLE group was enrolled between 2004-2018; the SOLE group had data from 1999-2012.

Key points:

  • Among FOLE recipients (n=189), 65% experienced cholestasis resolution vs 16% of SOLE recipients (n=73) (P < .0001).
  • The aspartate aminotransferase to platelet ratio index scores improved in FOLE recipients (1.235 vs 0.810 and 0.758, P < .02) but worsened in SOLE recipients (0.540 vs 2.564 and 2.098; P ≤ .0003) 
  • Liver transplantation was reduced in FOLE vs SOLE (4% vs 12%; P = .0245).

My main criticisms of the study:

  1. While the methods explain that FOLE received 1 gm/kg/d, compared with 3 gm/kg/d for SOLE, this was NOT reviewed in the discussion. This is quite important in terms of proving that one product is preferred over the other. With lipid toxicity, it would be expected that delivering 3 times as much would be more damaging on the liver.
  2. The discussion does not discuss the potential neurological consequences of lipid minimization/lower doses of lipids. In the same Journal of Pediatrics issue, Bell et al report that 77% of SBS in their cohort of extremely premature infants with short bowel syndrome had moderate-to-severe neurodevelopmental impairment (related blog post: Neurodevelopmental Impairment in the Majority of Extremely Premature Infants with Short Bowel Syndrome)
  3. The discussion has only a single sentence regarding the change in care between the eras of SOLE and FOLE: “Additional limitations include a relatively small sample size and changes in surgical, medical, and nutritional practice between the 2 eras that could not be controlled for this study.”
  4. Also, the discussion omits the development of other FOLE alternatives (eg. SMOFlipid) which has been a very important advance in the management of patients with SBS.

The commentary by Samuel Kocoshis (J Pediatr 2021; 230: 11-12) provides a good deal of insight. The title and first paragraph provides some interesting historical context: (full text) “Even When the Would Is Healed, the Scar Remains” “The above maxim was coined by the Roman author Publilius Syrus when referring to wounds of most tissues or body parts.1 Because hepatic regeneration was recognized (as evidenced by the story of Prometheus’s liver being eaten daily by an eagle only to regenerate the next day) in Syrus’s time, his dictum was too far too simplistic when applied to the liver. One must delve more deeply into the mechanism of liver injury to ascertain just when hepatic scaring persists or when it disappears.”

My take: This study illustrates harm reduction with the change in lipid administration. The development of new lipid products has made a huge difference in the outcomes of children with short bowel syndrome.

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