interpreting methacholine challenge assessment
- related: PFT and lung functions
- tags: #literature
| Provocative Concentration (PC20) | Interpretation |
|---|---|
| >16 mg/ml | Normal |
| 4-16 mg/ml | Borderline |
| 1-4 mg/ml | Mild |
| 0.25-1 mg/ml | Moderate |
| <0.25 mg/ml | Marked/Severe |
- Positive test: If concentration ≤ 4mg/ml achieves drop in FEV1 of 20% or greater