Table 1. Baseline characteristics of patients with respiratory failure after extubation.
| Characteristic | NIV success (n=69) | NIV failure (n=43) | P value |
|---|---|---|---|
| Age (years) | 59.4±11.5 | 0.365 | |
| Male sex, n (%) | 47 (68.1) | 25 (58.1) | 0.284 |
| BMI (kg/m2) | 24.8±3.5 | <0.001 | |
| BMI, n (%) | 0.011 | ||
| <18.5 | 4 (5.8) | 9 (20.9) | |
| 18.5–23 | 15 (21.7) | 16 (37.2) | |
| 23–25 | 16 (23.2) | 9 (20.9) | |
| 25–30 | 30 (43.5) | 8 (18.6) | |
| ≥30 | 4 (5.8) | 1 (2.3) | |
| Underlying disease, n (%) | |||
| Diabetes | 10 (14.5) | 6 (14.0) | 0.937 |
| Smoking | 18 (26.1) | 11 (25.6) | 0.953 |
| COPD | 0 (0) | 4 (9.3) | 0.04 |
| Hypertension | 46 (66.7) | 17 (39.5) | 0.005 |
| LVEF, % | 58.2±9.9 | 0.642 | |
| Type of surgery, n (%) | 0.019 | ||
| Valve | 22 (31.9) | 22 (51.2) | |
| CABG | 17 (24.6) | 7 (16.3) | |
| CABG + valve | 10 (14.5) | 6 (14.0) | |
| Aorta | 20 (29.0) | 5 (11.6) | |
| Other | 0 (0) | 3 (7.0) | |
| EuroSCORE | 6.78±2.86 | 0.536 | |
| Preoperative PaO2/FiO2 | 330.0±124.3 | 0.447 | |
| Total CPB time (min) | 114.2±42.4 | 0.7 | |
| Total aortic block time (min) | 64.7±30.0 | 0.861 | |
| Surgical re-exploration, n (%) | 7 (10.1) | 4 (9.3) | 1 |
| Blood transfusion, n (%) | 20 (29.0) | 25 (58.1) | 0.002 |
| Underlying cause of ARF, n (%) | <0.001 | ||
| Lobar atelectasis | 25 (36.2) | 6 (14.0) | |
| Pneumonia | 9 (13) | 18 (41.9) | |
| Acute cardiogenic oedema | 15 (21.7) | 8 (18.6) | |
| Post-CPB lung impairment | 12 (17.4) | 7 (16.3) | |
| Reactive airway disease | 0 (0) | 2 (4.7) | |
| Neuromuscular disease | 3 (4.3) | 1 (2.3) | |
| Hypercapnic pump failure | 2 (2.9) | 0 (0) | |
| Others (pneumothorax, shock) | 3 (4.3) | 1 (2.3) | |
| Pre-extubation PaO2/FiO2 | 278±90 | 0.516 | |
| Post-extubation PaO2/FiO2 | 233±82 | 0.828 | |
| Duration of MV (hours) | 43.7 (22.3–102.2) | 48.0 (21.1–145.2) | 0.599 |
Data were presented as mean ± SD or median (interquartile range), categorical variables were presented as number (%). ARF, acute respiratory failure; BMI, body mass index; CPB, cardiopulmonary bypass; COPD, chronic obstructive pulmonary disease; CABG, coronary artery bypass grafting; h, hours; LVEF, left ventricular ejection fraction; MV, mechanical ventilation; PaO2/FiO2, arterial oxygen tension/fraction of inspired oxygen; EuroSCORE, European System for Cardiac Operative Risk Evaluation.