Table 1 Patients’ characteristics and conditions at ICU admission and at discharge according to HFNO outcome
Parameters | Overall population | HFNO success group | HFNO failure group | p-value* |
|---|---|---|---|---|
n = 99 | n = 50 | n = 49 | ||
Characteristics at ICU admission | ||||
Age (years) | 67 (54–73) | 61 (51–72) | 68 (61–73) | 0.0592 |
Sex M/F, n (%) | 66/33 (67%/33%) | 31/19 (62%/38%) | 35/14 (71%/29%) | 0.3210 |
BMI (kg/m2) | 28.0 (25.2–32.0) | 28.1 (25.3–32.4) | 27.8 (24.8–30.4) | 0.2676 |
Comorbidities, n (%) | ||||
Diabetes mellitus | 29 (29%) | 12 (24%) | 17 (35%) | 0.2445 |
Hypertension | 58 (59%) | 30 (60%) | 28 (57%) | 0.7730 |
Underlying cardiac disease | 17 (17%) | 6 (12%) | 11 (22%) | 0.1740 |
Underlying respiratory disease | 22 (22%) | 11 (22%) | 11 (22%) | 0.9572 |
Chronic renal failure | 6 (6%) | 3 (6%) | 3 (6%) | 0.9796 |
Chronic liver disease | 0 | 0 | 0 | – |
Immunosuppression | 14 (14%) | 9 (18%) | 5 (10%) | 0.2713 |
Other | 30 (30%) | 14 (28%) | 16 (33%) | 0.6147 |
SAPS II | 35 (26–43) | 29 (23–36) | 41 (34–49) | < 0.0001 |
SOFA score | 2 (2–4) | 2 (2–3) | 4 (2–5) | 0.0027 |
Acute renal failure, n (%) | 14 (14%) | 3 (6%) | 11 (22%) | 0.0277 |
Hemodynamic failure, n (%) | 12 (12%) | 0 | 12 (24%) | < 0.0001** |
Covid-19 history | ||||
Time since symptom onset (days) | 9 (7–13) | 9 (7–12) | 8 (7–14) | 0.7381 |
Hospital stay before ICU admission (days) | 1 (0–3) | 1 (0–3) | 1 (0–3) | 0.3852 |
Chest-X ray and/or CT-scan findings, n (%) | ||||
Type of pulmonary injuries | ||||
Ground-glass opacities | 89 (90%) | 46 (92%) | 43 (88%) | 0.7183 |
Crazy-paving | 49 (49%) | 29 (58%) | 20 (41%) | 0.1545 |
Consolidation | 64 (64%) | 36 (72%) | 28 (57%) | 0.2444 |
Unknown | 5 (5%) | 1 (2%) | 4 (8%) | - |
Severity of pulmonary injuries, n (%) | ||||
No. of affected quadrants | 4 (3–4) | 3 (2–4) | 4 (3–4) | 0.0119 |
Extension of injuries on chest X-ray or CT, n (%) | 0.0067 | |||
< 25% | 32 (32%) | 25 (50%) | 7 (14%) | |
25–50%, | 30 (30%) | 12 (24%) | 18 (37%) | - |
50–75% | 23 (23%) | 10 (20%) | 13 (27%) | - |
> 75% | 8 (8%) | 2 (4%) | 6 (12%) | - |
Unknown | 6 (6%) | 1 (2%) | 5 (10%) | - |
Associated pulmonary embolism, n (%) | 11 (11%) | 5 (10%) | 6 (12%) | 0.6382 |
Respiratory conditions at HFNO initiation | ||||
Time between ICU admission and HFNO initiation (hours) | 0.1 (0–1.4) | 0.1 (0–1.0) | 0.1 (0–2.0) | 0.9220 |
Flow rate (L/min) | 50 (30–50) | 45 (40–50) | 50 (30–50) | 0.2724 |
FiO2 (%) | 60 (50–70) | 50 (40–60) | 60 (50–80) | 0.0006 |
SpO2 (%) | 95 (93–97) | 96 (94–97) | 94 (92–96) | 0.0011 |
SpO2/FiO2 (%) | 163 (137–196) | 192 (158–238) | 155 (119–186) | 0.0004 |
RR (cycles/min) | 25 (20–29) | 24 (18–28) | 25 (22–30) | 0.3555 |
Rox index (SpO2/FiO2/RR) | 6.71 (5.27–9.50) | 7.92 (6.23–10.33) | 5.64 (4.57–7.37) | 0.0005 |
Arterial blood gas before HFNO initiation (n = 89) | ||||
PaO2 (mmHg) | 70 (62–83) | 78 (67–86) | 63 (57–73) | 0.0132 |
PaO2/FiO2 (mmHg) | 146 (117–181) | 160 (131–204) | 136 (109–163) | 0.0087 |
SaO2 (%) | 95 (93–97) | 96 (94–98) | 94 (91–96) | 0.0157 |
pH | 7.45 (7.42–7.47) | 7.45 (7.43–7.48) | 7.45 (7.41–7.47) | 0.6256 |
PaCO2 (mmHg) | 34 (32–40) | 35 (32–41) | 34 (32–38) | 0.2537 |
HCO3− (mmol/L) | 23.6 (21.7–25.9) | 23.6 (22.0–26.7) | 23.5 (21.1–25.4) | 0.3928 |
Conditions at discharge | ||||
Intubation, n (%) | 46 (46%) | - | 46 (94%) | - |
Death before intubation, n (%) | 3 (3%) | - | 3 (6%) | - |
HFNO duration (hours) | 54 (22–147) | 136 (49–183) | 28 (11–61) | < 0.0001*** |
Standard O2 at ICU discharge among survivors, n (%) | 63 (75%) | 41 (82%) | 22 (65%) | 0.1222** |
Flow rate (L/min) | 2 (1–3) | 3 (2–3) | 2 (1–3) | 0.0184*** |
ICU mortality at day 28 after ICU admission, n (%) | 13 (13%) | 0 | 13 (27%) | < 0.0001** |
ICU length of stay (days) | 11 (6 -19) | 7 (5 -11) | 19 (12 -27) | < 0.0001*** |
ICU mortality, n (%) | 15 (15%) | 0 | 15 (31%) | < 0.0001** |
Hospital length of stay (days) | 21 (13–36) | 18 (12–25) | 31 (15–54) | 0.0025*** |
Hospital mortality after ICU discharge, n (%) | 0 | 0 | 0 | - |