Table 2 Changes in physiological variables induced by high-flow nasal cannula and noninvasive ventilation
Variables | Baseline | NIV | HFNT | p Baseline versus NIV | p Baseline versus HFNT | p NIV versus HFNT |
|---|---|---|---|---|---|---|
Respiratory pattern | ||||||
Respiratory rate (min−1) | 21 (17–26) | 19 (18–26) | 18 (13–20) | 0.99 | 0.01 | 0.13 |
Tidal volume (mL/kg) | 5.4 (4.3–10.6) | 5.6 (3.9–10.6) | 5.6 (4.2–10.2) | 0.49 | 0.49 | 0.02 |
Minute ventilation (L/min) | 6.9 (5.3–11.5) | 5.6 (5.0–8.4) | 5.0 (4.2–6.6) | 0.46 | 0.01 | 0.46 |
SpO2 (%) | 93 (90–94) | 93 (92–94) | 94 (93–95) | 0.99 | 0.30 | 0.51 |
Transcutaneous CO2 (mmHg) | 53 (42–60) | 53 (41–60) | 54 (41–60) | 0.99 | 0.98 | 0.99 |
Hemodynamic | ||||||
Heart rate (min−1) | 108 (89–114) | 101 (92–115) | 102 (91–114) | 0.94 | 0.43 | 0.99 |
Mean arterial pressure (mmHg) | 85 (78–91) | 91 (81–101) | 84 (77–94) | < 0.01 | 0.99 | 0.01 |
Diaphragm activity | ||||||
Thickening fraction (%) | 30 (25–46) | 35 (23–41) | 36 (19–41) | 0.99 | 0.99 | 0.99 |
Symptoms | ||||||
Dyspnea | 1 (0–3) | 1 (0–2) | 1 (0–3) | 0.82 | 0.99 | 0.99 |
Comfort | 9 (8–10) | 7 (6–9) | 6 (5–8) | 0.02 | < 0.01 | 0.99 |