Data on effects of acute changes in pulmonary blood flow on lung mechanics
| ASD occlusion (n=9) | PS occlusion (n=8) | ||||
|---|---|---|---|---|---|
| Age (years) | 12.3 (11.7) | 4.8 (8.5) | |||
| Median 9.5 | Median 1.2 | ||||
| Haemodynamics | (n=3) | (n=6) | |||
| Qp:Qs ratio | 3.5 (0.9):1 | 1:1 | |||
| RVSPpre (mm Hg) | 35.7 (5.3) | 72.3 (18.4) | |||
| RVSPpost (mm Hg) | 32.2 (7.9) | NS | 44.6 (22.5) | p < 0.001 | |
| Tidal volume (ml/kg) | |||||
| mbaseline | 9.61 (0.85) | 9.71 (2.95) | |||
| CVbaseline(%) | 0.66 (0.21) | 0.90 (0.64) | |||
| mintervention | 9.52 (0.97) | 9.32 (2.84) | |||
| z Scoreintervention | 2.04 (0.31) | p < 0.05 | 3.06 (0.86) | p < 0.05 | |
| Airway pressures (mm Hg) | |||||
| Pmin | mbaseline | 2.31 (1.70) | 2.40 (1.20) | ||
| CVbaseline(%) | 11.90 (2.54) | 16.90 (7.80) | |||
| mintervention | 2.32 (1.80) | 1.90 (1.00) | |||
| z Scoreintervention | 0.35 (0.21) | NS | 0.60 (0.23) | p < 0.01 | |
| Pmax | mbaseline | 20.6 (2.9) | 18.2 (3.0) | ||
| CVbaseline (%) | 1.23 (0.23) | 2.22 (0.86) | |||
| mintervention | 20.8 (3.1) | 19.2 (3.3) | |||
| z Scoreintervention | 1.79 (1.17) | NS | 1.45 (0.40) | p < 0.01 | |
| P0 | mbaseline | 4.30 (0.30) | 4.40 (0.40) | ||
| CVbaseline(%) | 8.54 (3.21) | 9.25 (4.73) | |||
| mintervention | 4.10 (0.50) | 2.30 (0.70) | |||
| z Scoreintervention | 2.42 (1.45) | NS | 4.29 (1.83) | p < 0.01 | |
| Dynamic compliance (ml/cm H2O*kg) | |||||
| mbaseline | 0.64 (0.11) | 0.72 (0.29) | |||
| CVbaseline(%) | 1.97 (0.47) | 2.33 (0.76) | |||
| mintervention | 0.59 (0.10) | 0.64 (0.26) | |||
| z Scoreintervention | 3.02 (1.59) | p < 0.01 | 3.68 (0.62) | p < 0.001 | |
| Airway resistance (cm H2O/litre*s) | |||||
| mbaseline | 15.70 (0.90) | 25.10 (1.70) | |||
| CVbaseline(%) | 2.72 (1.26) | 6.57 (2.23) | |||
| mintervention | 16.40 (0.90) | 28.80 (1.60) | |||
| z Scoreintervention | 0.84 (0.76) | NS | 3.07 (1.51) | p < 0.01 | |
The values from multiple measurements were averaged for each patient, and then by patient group. Thus the resulting value 1 (± value 2) given is the mean and its standard deviation of all averaged values per patient (that is, 9 in the ASD group, and 8 in the PS group).
ASD, atrial septal defect; CVbaseline, coefficient of variation of the baseline measurement; mbaseline, mean value at baseline; mintervention, mean value during intervention; Pmax, Pmin, and P0, maximum, minimum airway pressure, and calculated end expiratory airway pressure; PS, pulmonary stenosis; Qp:Qs ratio, ratio of pulmonary to systemic blood flow; RSVP, right ventricular systolic pressure; z scoreintervention, deviation of the measurements during intervention from that of the baseline, expressed as a multiple of the baseline variability.