Normal Lactate Level in a 13-Year-Old Boy with Aganglionic Colon
A normal plasma lactate level is less than 2 mmol/L, regardless of whether the patient has an aganglionic colon. 1, 2
Standard Reference Range
- Normal lactate: <2 mmol/L 1, 2
- Elevated lactate: ≥2 mmol/L (indicates potential tissue hypoperfusion or metabolic dysfunction) 1
- Abnormal lactate: >5 mmol/L (serious/life-threatening) 1
- Critical lactate: >10 mmol/L (life-threatening emergency) 1
Critical Consideration: D-Lactic Acidosis Risk
In a 13-year-old with aganglionic colon (Hirschsprung's disease), you must specifically consider D-lactic acidosis if the patient has undergone bowel resection resulting in short bowel syndrome with preserved colon. 3, 1, 4, 5
When to Suspect D-Lactic Acidosis
D-lactic acidosis should be suspected when: 3, 1, 5
- Neurological symptoms: confusion, weakness, ataxia, slurred speech, lethargy (sometimes bordering on coma) 5
- Gastrointestinal symptoms: nausea, vomiting 1
- Metabolic acidosis: pH <7.35 with elevated anion gap (>16) 1
- Standard L-lactate may be normal or only mildly elevated 3, 4
D-Lactate Specific Values
- Normal D-lactate: <0.1 mmol/L 4
- Elevated D-lactate: >0.25 mmol/L (diagnostic threshold in pediatric studies) 6
- Significantly elevated: >2.0 mmol/L (associated with clinical symptoms) 4, 5
- Severe D-lactic acidosis: >5.0 mmol/L (as seen in case reports) 5
Important Clinical Pitfalls
Standard lactate measurements in most laboratories measure only L-lactate, NOT D-lactate. 3, 1 If you suspect D-lactic acidosis based on:
- Short bowel syndrome with preserved colon 3, 1, 4
- Unexplained neurological symptoms with metabolic acidosis 5, 6
- High carbohydrate intake (especially simple sugars) 3, 4
You must specifically order a D-lactate level, as it requires specialized testing. 3, 4, 5
Risk Factors for D-Lactic Acidosis in This Population
- History of midgut volvulus (strongest independent risk factor, adjusted OR = 17.1) 6
- Intestinal lengthening procedures 6
- Short bowel length (median 40 cm in affected patients) 6
- Preserved colon (essential for D-lactate production by colonic bacteria) 3, 1, 4
- High carbohydrate diet, particularly mono- and oligosaccharides 3, 4
Specimen Considerations
Plasma lactate is the gold standard for clinical decision-making, as whole blood lactate measurements are typically 10-15% higher than plasma values due to red blood cell lactate content. 2 Always specify plasma lactate when ordering to ensure accurate interpretation against the <2 mmol/L threshold. 2