Related Experiment Videos
Acquired carnitine abnormalities in critically ill children
F Proulx1, J Lacroix, I A Qureshi
1Department of Paediatrics, Sainte-Justine Hospital, Montreal, Quebec, Canada.
Insights
Critically ill children often show abnormal carnitine levels in plasma and urine. The clinical significance of these carnitine changes is currently unknown.
Area of Science:
- Biochemistry
- Pediatric Critical Care
- Metabolic Disorders
Background:
- Carnitine plays a vital role in fatty acid metabolism.
- Metabolic stress in critically ill patients can impact nutrient utilization.
- Secondary carnitine deficiency can arise from various conditions.
Purpose of the Study:
- To investigate carnitine profiles in critically ill children without pre-existing metabolic disorders.
- To determine the frequency and patterns of abnormal carnitine levels during critical illness.
Main Methods:
- Prospective study of 28 critically ill children.
- Measurement of plasma and urine carnitine levels at multiple time points (admission, days 2, 5, 10, 15).
- Analysis of free carnitine (FC) and esterified carnitine.
Main Results:
- Over 25% of plasma and 50% of urine carnitine measurements were abnormal.
- 96% of patients exhibited at least one abnormal plasma carnitine value.
- Three children had extremely low plasma free carnitine levels.
- Admission carnitine levels did not correlate with mortality risk, muscle lysis, or caloric intake.
Conclusions:
- Abnormal plasma and urine carnitine levels are common in critically ill children.
- The clinical significance of these carnitine perturbations requires further investigation.
- Abnormal carnitine values in this population should be interpreted cautiously, avoiding premature assumptions of hereditary metabolic disorders.
Unlabelled:
In order to characterize the role of carnitine during metabolic stress, we prospectively determined carnitine profiles in plasma and urine on admission, days 2, 5, 10 and 15, among 28 critically ill children free of any known conditions associated with secondary carnitine deficiency. More than 25% of plasma and 50% of urinary carnitine measurements were abnormal; 96% (27/28) of patients displayed on at least one occasion an abnormal [< -2 SD or > +2 SD] carnitine value in plasma. Three children had extremely low [< 10 micromol/l] free carnitine (FC) levels in plasma. Plasma esterified and FC levels on admission were not related to the risk of mortality [PRISM score], to muscle lysis [CK values], and to the caloric intake. Levels of FC and esterified carnitine in plasma were unrelated to those measured in urine.
Conclusion:
Abnormal plasma and urine carnitine measurements are frequently found in critically ill children; the biological significance of these perturbations remains unclear. Caution must be exercised before concluding that an abnormal carnitine value is indicative of an underlying hereditary metabolic disorder in this population.