TABLE 4

Comparison between physiological effects of face mask (FM) and noninvasive ventilation (NIV)

FMNIVNIV–FM
Median (IQR)Median (IQR)Median (95% CI)p-value#
VT global (units)2402 (1641–3050)3161 (1884–3805)606.0 (441.5–792.0)<0.0001
VT ROI1 (units)593 (566–737)887 (657–1033)182.5 (97.0–269.0)0.001
VT ROI2 (units)479 (321–683)686 (413–925)182.5 (122.5–251.0)<0.0001
VT ROI3 (units)649 (427–836)743 (498–1008)132.5 (73.5–194.5)0.0002
VT ROI4 (units)383 (259–772)444 (318–861)98.5 (17.0–178.0)0.02
VT consolidation (units)593 (160–819)778 (338–1002)151.0 (58.0–215.5)0.009
EELI global (units)1999 (764–2779)4083 (2928–5134)1810.5 (857.0–2646.0)0.001
EELI ROI1 (units)327 (115–618)842 (646–1144)518.0 (315.5–779.0)<0.0001
EELI ROI2 (units)361 (135–880)960 (469–1406)457.5 (130.0–818.0)0.009
EELI ROI3 (units)317 (144–567)767 (336–1124)414.0 (76.0–678.5)0.02
EELI ROI4 (units)382 (115–572)846 (488–971)374.0 (108.0–670.5)0.01
EELI consolidation (units)562 (160–776)899 (767–1144)404.5 (59.0–718.0)0.02
Respiratory rate (breaths·min−1)26 (25–30)24 (22–27)−2 (−6–2)0.6
SpO2/FiO2 ratio152 (145–152)167 (143–200)21.0 (2.5–50.0)0.03
SpO2 (%)100 (96–100)100 (98–100)0 (0–2)0.3
Heart rate (beats·min−1)85 (79–103)84 (68–98)−1 (−3–5)0.8
SBP (mmHg)122 (109–129)119 (108–131)−1 (−7–11)1.0
MAP (mmHg)84 (77–91)80 ( 76–89)−1 (−2–4)1.0
Dyspnoea score (0–10)2 (0–5)5 (0–5)0 (−1–3)0.5
Patient comfort score (0–10)8 (5–10)4 (2–5)−3 (−5− −1)0.001

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.