Parenteral nutrition-associated cholestasis (PNAC) may affect preterm infants requiring parenteral nutrition following intestinal perforation or other cause. The aspartate aminotransferase to platelet ratio index can help to identify a patient at increased risk for PNAC. The authors are from Srinakharinwirot University in Thailand and the University of California at Davis.
Patient selection: gestational age < 34 weeks, birthweight < 2,000 grams, intestinal perforation (spontaneous, necrotizing enterocolitis, other), receiving parenteral nutrition
Parameters at 2 weeks after start of TPN:
(1) serum AST in U/L
(2) upper limit of normal reference range for AST in I/L
(3) platelet count in 10^9/L
AST to platelet ratio index = APRI =
= ((serum AST) / (upper limit of normal for AST)) / (factor from platelet count) * 100 =
= 100 * (serum AST) / ((upper limit normal AST) * (factor for platelet count))
Interpretation:
• An APRI >= 0.4775 within 2 weeks of perforation was associated with PNAC
Performance:
• The area under the ROC curve was 0.90.
