Table 3
Threshold concentration (TC) for the infant lung function parameters
| Patient no | TC FEV0.5 | TC Raw | TC Iaw | TC G | TC H | TC η |
| 1 | 1 | – | – | 0.25 | – | – |
| 2 | 0.25 | 0.25 | – | – | 0.25 | – |
| 3 | 1 | 1 | 1 | – | – | 1 |
| 4 | 4 | 2 | 2 | 2 | – | 4 |
| 5 | 0.5 | 0.5 | 0.25 | 0.25 | – | – |
| 6 | 2 | 1 | 1 | 0.25 | – | 0.25 |
| 7 | 0.25 | 0.5 | 0.5 | 0.5 | – | 0.5 |
| 8 | 0.25 | 0.25 | 0.25 | 0.25 | – | 0.25 |
| 9 | Aw | – | – | 2 | – | 2 |
| 10 | 4 | – | – | 4 | – | 4 |
| 11 | 1 | 1 | – | 0.25 | 1 | – |
| 12 | 2 | – | 0.5 | – | 0.5 | – |
| 13 | 2 | – | – | 0.5 | – | 1 |
| 14 | 2 | 4 | 0.5 | 8 | – | 8 |
| 15 | 4 | – | – | – | – | – |
| 16 | 2 | 0.25 | 0.25 | 0.25 | – | 1 |
| 17 | 0.5 | – | – | – | 0.5 | – |
| Median (25% to 75% CI) | 1.5 (0.5 to 2) | 0.75 (0.25 to 1) | 0.5 (0.25 to 1) | 0.375 (0.25 to 2) | 0.5 (0.375 to 0.75) | 1 (0.5 to 4) |
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Raw = airway resistance; Iaw = airway inertance; G = tissue damping; H = tissue elastance; η = tissue hysteresivity; – = parameters not reaching threshold concentration.
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One infant woke spontaneously before the end of the test (patient 9).
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Threshold concentrations for each parameter are expressed in mg/ml methacholine. There were no significant differences between the threshold concentrations in any lung function parameter.
