Table 1. Effect of nitrogen excretion on LCI and FRC for different lung model scenarios.
| FRC (L) | R (L/min) | DS | X | LCI, LCI (N2)(% error) | FRC, FRC (N2)(% error) | Contribution of excreted N2 at LCI point (%) | |
| Healthy adult | 3 | 10 | 0.3 | 0.5 | 5.27, 5.50 (4.4) | 3.00, 3.05 (1.8) | 21% |
| CF Adult | 3 | 10 | 0.45 | 0.7 | 8.96, 9.45 (5.5%) | 3.00, 3.09 (3.1) | 23% |
| CF child-Reduced N2* | 2 | 7 | 0.5 | 0.7 | 9.64, 10.2 (5.8) | 2.00, 2.06 (3.08) | 24% |
| CF child-Increased N2+ | 2 | 7 | 0.5 | 0.7 | 9.64, 10.93 (13.4) | 2.00, 2.14 (7.1) | 49% |
For the two CF child scenarios: * - N2 excretion reduced by a factor of 0.45; +- N2 excretion increased by a factor of 1.6.
FRC: functional residual capacity, R: minute ventilation, DS: deadspace, X: ventilation heterogeneity (fractional ventilation distribution), LCI: lung clearance index.