Plasma triglycerides analyses are necessary to evaluate the clearance of intravenous fat emulsions in patients receiving parenteral nutrition. This study investigates the clinical correlation between plasma triglycerides and lipid levels determination.

Method: In the Neonatal Intensive Care Unit, at Kingston General Hospital, Kingston, Ontario, from January to July 1996, a total of 312 samples were taken from 55 patients receiving parenteral nutrition and analysed concomitantly for total triglycerides and lipid levels. In addition, retrospectively other clinical parameters were reviewed for each patient, namely intralipid infusion rates, weight gain, severity of illness, documented infection and medication usages.

Results: 289 samples analysed showed normal total triglyceride levels(0.6-2.3 mmol/L) and correlated with normal total lipid levels(0.1-1.2g/l) from the same patients. Abnormal values were documented in 23 samples:7 elevated triglyceride levels with similarly elevated lipid levels; 7 elevated triglyceride levels with normal lipid levels; and 9 elevated total lipid levels with normal triglycerides.

Review of other clinical parameters for each of the patients showed that they received appropriate infusion of intralipids(20%) based on the total triglyceride levels, which is the present standard practice for this NICU. Infection was documented on 11 occasions and not associated with abnormally high triglyceride or lipid levels.

Conclusion: With the present accuracy of the plasma triglyceride analyses, the clinical management of the sick neonates requiring intravenous fat emulsions had been appropriate. The more costly lipid levels were justified in demonstrated abnormal triglyceride levels. Thus we recommend that these should only be done on a selected basis. Proven infection did not appear to be associated with hypertriglyceridemia or high lipid levels. We postulate the role of glycerol affecting the total triglyceride levels of some of the abnormally high values. Therefore, further studies would need to be done to ascertain its effect.