Parenteral nutrition in ventilated patients with chronic obstructive pulmonary disease: long chain vs medium chain...

The aim of this study was to assess the usefulness of a lipid formulation containing a physical mixture of medium (MCT) and long chain triglycerides (LCT) compared with a long chain triglycerides emulsion in patients affected by chronic obstructive pulmonary disease with acute respiratory failure.

Twenty-four patients requiring mechanical ventilation were randomly selected in 2 groups and received total parenteral nutrition. Twelve patients received a MCT/LCT emulsion (50:50), the others used a 100% LCT emulsion. Nutritional status, metabolic rate, time of ventilatory support and weaning were evaluated.

Both groups showed an improvement of all nutritional parameters evaluated; oxygen uptake, carbon dioxide output and respiratory gas exchange ratio were similar in both groups. The duration of mechanical ventilation was not significantly different; however, the time of weaning in the MCT/LCT group was significantly shorter. The longer weaning time in the LCT group patients could be related to vasoactive intermediates deriving from long chain fatty acids. The T-cell subsets, which were evaluated for both groups, showed a significant decrease of T helper-T suppressor ratio in the LCT group.

MCT/LCT emulsion is an effective lipid supplementation and should be considered the therapy of choice in COPD patients; however, the relationship between lipid emulsions administered and length of weaning requires further investigations.