Table 2 Characteristics of patients according to the success or failure of the first separation attempt from high-flow nasal oxygen therapy
Variables | Success (n = 168) | Failure (n = 22) | p value |
|---|---|---|---|
Baseline characteristics | |||
Age, years | 61 ± 15 | 61 ± 14 | 0.93 |
Gender, female, n | 55 (33%) | 6 (27%) | 0.81 |
Simplified acute physiology score II, points | 36 ± 12 | 40 ± 13 | 0.22 |
Sequential organ failure assessment score, points | 5 ± 3 | 5 ± 4 | 0.74 |
Comorbidities, n | |||
Chronic cardiac failure | 32 (19%) | 4 (18%) | > 0.99 |
Chronic respiratory failure | |||
Obstructive | 31 (18%) | 5 (23%) | 0.85 |
Restrictive | 10 (5.9%) | 2 (9.1%) | 0.92 |
Immunosuppression | 56 (33%) | 8 (36%) | 0.97 |
Main reason for acute respiratory failure, n | |||
Pneumonia | 79 (47%) | 16 (73%) | 0.04 |
Cardiogenic pulmonary edema | 28 (17%) | 1 (4.5%) | 0.21 |
Extrapulmonary sepsis | 26 (15%) | 1 (4.5%) | 0.32 |
Acute exacerbation of chronic respiratory failure | 9 (5.4%) | 1 (4.5%) | > 0.99 |
Pulmonary embolism | 7 (4.2%) | 1 (4.5%) | > 0.99 |
Shock | 4 (2.4%) | 0 (0%) | > 0.99 |
Neurological failure | 4 (2.4%) | 0 (0%) | > 0.99 |
Drug abuse | 2 (1.2%) | 0 (0%) | > 0.99 |
Other diagnoses | 1 (6.0%) | 2 (9.1%) | 0.63 |
Characteristics before the first separation attempt from HFOT | |||
Bilateral infiltrates at chest X-ray, n | 59 (35%) | 10 (45%) | 0.48 |
Vasoactive drugs, n | 8 (5%) | 0 (0%) | 0.63 |
Length of treatment with HFOT, hours | 41 (23–72) | 56 (39–80) | 0.26 |
Last clinical and biological parameters before the first separation attempt from HFOT | |||
Flow, L/min | 42 ± 8 | 43 ± 8 | 0.54 |
FiO2 set, % | 39 ± 7 | 48 ± 16 | 0.02 |
Temperature, °C | 37.3 ± 0.8 | 37.4 ± 0.8 | 0.54 |
Systolic arterial pressure, mmHg | 125 ± 19 | 127 ± 19 | 0.68 |
Heart rate, beats/min | 92 ± 19 | 94 ± 20 | 0.60 |
Respiratory rate, breaths/min | 21 ± 5 | 22 ± 5 | 0.59 |
Pulse oximetry, % | 96 ± 2 | 96 ± 2 | 0.36 |
SpO2/FiO2, % | 254 ± 45 | 217 ± 53 | 0.004 |
ROX index | 12.7 ± 1.2 | 10.2 ± 3.0 | 0.002 |
PaO2, mmHg | 95 ± 33 | 96 ± 33 | 0.92 |
PaCO2, mmHg | 35 ± 7 | 36 ± 8 | 0.68 |
pH | 7.45 ± 0.05 | 7.44 ± 0.05 | 0.72 |
Serum bicarbonate, mmol/L | 24 ± 5 | 24 ± 5 | 0.99 |
Last PaO2/FiO2 under HFOT, mmHg | 226 ± 64 | 210 ± 72 | 0.35 |
Sequential organ failure assessment score, points | 3 ± 2 | 1 ± 2 | 0.27 |
First clinical parameters under standard oxygen after the separation attempt from HFOT | |||
Flow, L/min | 4 ± 1 | 5 ± 1 | 0.02 |
Temperature, °C | 37.4 ± 0.7 | 37.4 ± 0.9 | 0.92 |
Systolic arterial pressure, mmHg | 125 ± 18 | 131 ± 17 | 0.15 |
Heart rate, beats/min | 91 ± 18 | 92 ± 16 | 0.75 |
Respiratory rate, breaths/min | 23 ± 5 | 22 ± 5 | 0.39 |
Pulse oximetry, % | 96 ± 3 | 95 ± 3 | 0.13 |
SpO2/FiO2, % | 286 ± 39 | 263 ± 28 | 0.001 |
ROX index | 13.3 ± 3.9 | 12.7 ± 3.2 | 0.47 |
Outcomes | |||
Total length of HFOT treatment, h | 41 (23–72) | 84 (61–118) | < 0.0001 |
ICU length of stay, days | 5 (4–8) | 10 (7–12) | < 0.0001 |
Time from HFOT separation success to ICU discharge, days | 2 (1–3) | 2 (2–3) | 0.21 |