Systematic review and meta-analyses of the effect of lipid emulsion on microbial growth in parenteral nutrition

J Hosp Infect. 2016 Dec;94(4):307-319. doi: 10.1016/j.jhin.2016.08.026. Epub 2016 Sep 7.

Abstract

Background: As lipid in parenteral nutrition (PN) purportedly enhances microbial growth, recommendations limit infusion of lipid PN (or lipid emulsion) from a single container to 24h (48h for lipid-free PN). However, the associated evidence base is ambiguous.

Aim: To examine factors affecting microbial growth in PN.

Methods: A systematic review with meta-analyses examined effects of nutrients on microbial growth in PN infusates over a 48-h period using the growth ratio {GR=log10[colony-forming units (cfu)/mL at 48h/cfu/mL at time zero]}.

Findings: Factors influencing GR in PN included glucose, microbial species, temperature, osmolarity, presence of vitamins, trace elements and lipid, and amino acid profile. Using unmatched datasets (N=306), a general linear model found that lipid inclusion in PN represented 3.3% of the variability, which was less than that due to glucose concentration (5.8%), microbial species (35.3%) and microbe-infusate interaction (4.4%). Using matched datasets (N=38 pairs), lipid inclusion in PN represented 5.4% of the variability (P=0.076), which was less than that due to glucose concentration (8.5%; P=0.025), microbial species (75.5%; P<0.001) and microbe-infusate interaction (13.3%; P=0.382). Using meta-analyses of matched datasets, the presence of lipid in PN at fixed glucose concentrations did not significantly increase GR of Candida albicans, Escherichia coli or Staphylococcus epidermidis (P=0.352, P=0.025 and P=0.494, respectively; overall P=0.175).

Conclusion: Lipid inclusion in PN is only one of several factors that may influence microbial growth in PN. Any recommendations about the duration of PN infusion from a single container should account for all these factors, and should be weighted according to microbial species likely to contaminate PN.

Keywords: Catheter infection; Lipid; Microbial growth; Parenteral nutrition; Sepsis; Venous access.

Publication types

  • Meta-Analysis
  • Review
  • Systematic Review

MeSH terms

  • Bacteria / growth & development*
  • Candida albicans / growth & development*
  • Emulsions / administration & dosage
  • Humans
  • Lipids / administration & dosage*
  • Parenteral Nutrition*

Substances

  • Emulsions
  • Lipids