TABLE 3

Comparison between physiological effects of face mask (FM) and high-flow nasal cannula (HFNC)

FMHFNCHFNC–FM
Median (IQR)Median (IQR)Median (95% CI)p-value#
VT global (units)2240 (1421–2752)2323 (1497–2891)−3.0 (−138.5–153.5)0.9
VT ROI1 (units)618 (440–692)590 (464–774)−30.0 (−96.0–35.0)0.3
VT ROI2 (units)408 (295–703)445 (262–656)−18.5 (−63.5–37.0)0.4
VT ROI3 (units)597 (287–816)589 (271–909)14.5 (−27.5–113.0)0.5
VT ROI4 (units)290 (200–708)450 (286–664)15.0 (−21.0–77.0)0.4
VT consolidation (units)290 (233–760)489 (198–783)2.5 (−57.0–40.5)0.9
EELI global (units)1444 (992–3468)2921 (1706–4850)826.0 (399.5–2361.0)<0.0001
EELI ROI1 (units)278 (91–634)562 (215–1000)161.5 (−19.5–322.5)0.05
EELI ROI2 (units)325 (181–531)408 (355–1152)187.5 (−31.5–464.0)0.1
EELI ROI3 (units)378 (125–446)618 (370–1251)220.0 (57.0–719.0)0.01
EELI ROI4 (units)309 (130–499)447 (373–738)169.5 (31.0–1104.0)0.01
EELI consolidation (units)283 (125–477)486 (381–946)138.0 (24.5–613.0)0.01
Respiratory rate (breaths·min−1)25 (23–28)23 (21–26)−3 (−6–1)0.2
SpO2/FiO2 ratio152 (147–152)163 (140–200)16.0 (−6.0–48.0)0.1
SpO2 (%)100 (97–100)97 (96–100)0 (−2–1)0.5
Heart rate (beats·min−1)82 (72–102)90 (78–104)1 (−2–4)0.4
SBP (mmHg)118 (107–133)125 (113–137)6 (0–9)0.1
MAP (mmHg)81 (74–92)85 (77–94)2 (1–7)0.01
Dyspnoea score (0–10)0 (0–5)5 (2–5)0 (0–3)0.3
Patient comfort score (0–10)8 (4–9)5 (4–7)−2 (−4–0)0.1

Bold type reprensents statistical significance. IQR: interquartile range; VT: tidal volume variation; ROI: region of interest; EELI: end-expiratory lung impedance; SpO2: pulse oxygen saturation; FiO2: inspiratory oxygen fraction; SBP: systolic blood pressure; MAP: mean arterial pressure. #: Wilcoxon signed rank test.