Tables
- TABLE 1
Characteristics at inclusion and study outcomes, according to study group
Moderate-to-severe dyspnoea (n=52) Mild or no dyspnoea (n=57) Adjusted mean difference (95% CI) OR (95% CI) p-value Demographics Age, years 61 (53–70) 65 (58–71) 0.15 Female sex 9 (17) 12 (21) 0.64 Male sex 43 (83) 45 (79) 0.64 Body mass index, kg·m−2 28 (26–30) 27 (25–30) 0.37 Respiratory rate at enrolment, breaths per min 28 (24–33) 27 (23–30) 0.13 Device-related discomfort at enrolment# 2 (0–5) 0 (0–0) <0.001 Arterial blood gases at enrolment PaO2/FIO2 ratio, mmHg 97 (82–117) 110 (83–132) 0.12 PaO2, mmHg 60 (54–74) 66 (55–75) 0.71 pH 7.46 (7.45–7.49) 7.46 (7.45–7.48) 0.95 PaCO2, mmHg 34 (31–37) 34 (32–37) 0.50 Allocated treatment¶ Helmet noninvasive ventilation 27 (52) 27 (47) 0.70 High-flow oxygen 25 (48) 30 (53) 0.70 Outcomes Respiratory support+-free days at 28 days 12 (0–23) 21 (4–25) −5 (−8– −1) 0.008 Intubation within 28 days from enrolment 27 (52) 17 (30) 3.8 (1.5–9.9) 0.006 Invasive ventilation-free days at 28 days 20 (4–28) 28 (16–28) −5 (−9– −1) 0.02 Invasive ventilation free days at 60 days 52 (11–60) 60 (48–60) −9 (−17– −1) 0.03 28-day mortality 10 (19) 8 (14) 1.8 (0.6–5) 0.29 60-day mortality 14 (27) 11 (19) 2 (0.8–5.5) 0.16 Intensive care unit mortality 15 (29) 10 (17) 2.8 (1–7.7) 0.05 Hospital mortality§ 16 (31) 11 (19) 2.6 (1–7) 0.05 Length of stay in the intensive care unit, days 12 (6–29) 7 (4–12) 6 (0–6) 0.05 Length of stay in the hospital, days 24 (16–41) 18 (12–29) 8 (0–15) 0.04 Data are presented as median (interquartile range) or n (%), unless otherwise stated. There were no missing data among the two groups. Mean difference and odds ratio were adjusted for Simplified Acute Physiology Score II, allocated treatment (high-flow nasal oxygen or helmet noninvasive ventilation) and arterial oxygen tension (PaO2)/inspiratory oxygen fraction (FIO2) ratio on intensive care unit admission. For non-normal quantitative variables, comparison between groups was performed with Mann–Whitney test. Comparison between groups for qualitative variables were performed with the Chi-squared test or the Fisher's exact test, as appropriate in agreement with tests assumptions. All the calculations were unadjusted. PaCO2: arterial carbon dioxide tension. #: discomfort was assessed through visual analogue scales adapted for intensive care unit patients, ranging from 0 to 10; ¶: advanced respiratory support interface used in the first 48 h; +: invasive or noninvasive mechanical ventilation, high-flow nasal oxygen; §: one patient was discharged from hospital but died upon readmission.
