Table 2.
Primary and secondary outcomes by assigned treatment groups
| Characteristic | Tracheal tube + stylet (n = 501) | Tracheal tube alone (n = 498) | Absolute difference (95% CI) | Relative risk (95% CI) | P value |
|---|---|---|---|---|---|
| Primary: first-attempt intubation success tracheal intubation | 392 (78.2) | 356 (71.5) | 6.7 (1.4–12.1) | 1.1 (1.02–1.18) | 0.01 |
| Main secondary: complications related to intubation in the hour following intubation | 194 (38.7) | 200 (40.2) | − 1.5 (− 7.5 to 4.6) | 0.96 (0.83–1.12) | 0.64 |
| Severe complications | 128 (25.6) | 128 (25.7) | − 0.2 (− 5.6 to 5.3) | 0.99 (0.81–1.23) | 1.00 |
| Severe hypoxaemia | 69 (13.8) | 76 (15.3) | − 1.5 (− 5.9 to 2.9) | 0.9 (0.67–1.22) | 1.00 |
| Severe collapse | 71 (14.2) | 66 (13.3) | 0.9 (− 3.4 to 5.2) | 1.07 (0.78–1.46) | 0.92 |
| Cardiac arrest | 7 (1.4) | 7 (1.4) | 0 (− 1.5 to 1.5) | 0.99 (0.35–2.81) | 1.00 |
| Death | 0 (0) | 0 (0) | – | – | |
| Moderate complications | 101 (20.1) | 121 (24.3) | − 4.2 (− 9.3 to 1) | 0.83 (0.66–1.05) | 0.53 |
| Operator-assessed difficult intubation | 86 (17.2) | 116 (23.3) | − 6.1 (− 11.1 to − 1.2) | 0.74 (0.57–0.95) | 0.15 |
| Oesophageal intubation | 10 (2) | 12 (2.4) | − 0.4 (− 2.2 to 1.4) | 0.83 (0.36–1.9) | 0.97 |
| Operator-reported aspiration | 13 (2.6) | 5 (1) | 1.6 (− 0.1 to 3.2) | 2.58 (0.93–7.19) | 0.33 |
| Arrhythmia | 4 (0.8) | 1 (0.2) | 0.6 (− 0.3 to 1.5) | 3.98 (0.45–35.4) | 1.00 |
| Agitation | 2 (0.4) | 2 (0.4) | 0 (− 0.8 to 0.8) | 0.99 (0.14–7.02) | 1.00 |
| Dental injury | 1 (0.2) | 2 (0.4) | − 0.2 (− 0.9 to 0.5) | 0.5 (0.05–5.46) | 1.00 |
| Traumatic injuries | 20 (4) | 18 (3.6) | 0.4 (− 2 to 2.8) | 1.1 (0.59–2.06) | 0.76 |
| Mucosal bleeding | 17 (3.4) | 17 (3.4) | 0 (− 2.3 to 2.2) | 0.99 (0.51–1.92) | 0.99 |
| Laryngeal injuries | 2 (0.4) | 2 (0.4) | 0 (− 0.8 to 0.8) | 0.99 (0.14–7.02) | 1.00 |
| Tracheal injuries | 0 (0) | 1 (0.2) | − 0.2 (− 0.6 to 0.2) | – | 0.50 |
| Mediastinal injuries | 1 (0.2) | 0 (0) | 0.2 (− 0.2 to 0.6) | – | 1.00 |
| Oesophageal injuries | 2 (0.4) | 0 (0) | 0.4 (− 0.2 to 1) | – | 0.50 |
| Exploratory safety outcomes | |||||
| Lowest peripheral oxygen saturation, % | 92.8 ± 7.4 | 92.9 ± 7.9 | − 0.1 (− 1 to 0.9) | – | 0.46 |
| Highest fraction of inspired oxygen, % | 51.5 ± 23.9 | 50.7 ± 24.1 | 0.8 (− 2.3 to 3.9) | – | 0.47 |
| Highest positive end-expiratory pressure, % | 7.9 ± 3.3 | 7.8 ± 3.3 | 0.1 (− 0.3 to 0.6) | – | 0.69 |
| Number of laryngoscopy attempts | – | – | 0.22 | ||
| 1 | 392 (78.2) | 356 (71.5) | |||
| 2 | 89 (17.8) | 130 (26.1) | |||
| 3 | 18 (3.6) | 11 (2.2) | |||
| 4 | 1 (0.2) | 1 (0.2) | |||
| 5 | 1 (0.2) | 0 (0) | |||
| Exploratory clinical outcomesa | |||||
| ICU length of stay, days | 9.7 ± 8.6 | 10 ± 8.9 | − 0.3 (− 1.4 to 0.8) | – | 1.00 |
| ICU-free days, days | 12 ± 10.7 | 12.1 ± 10.8 | − 0.1 (− 1.5 to 1.2) | – | 0.96 |
| Invasive ventilator-free days, days | 14.5 ± 11.1 | 14.4 ± 11.3 | 0.1 (− 1.3 to 1.5) | – | 1.00 |
| 28-day mortality | 158 (31.5) | 150 (30.1) | 1.6 (− 4.1 to 7.4) | 1.05 (0.87–1.26) | 0.99 |
| 90-day mortality | 180 (35.9) | 188 (37.8) | − 1.6 (− 7.6 to 4.4) | 0.95 (0.81–1.12) | 1.00 |
Data are mean (SD) or n (%)
aThe P value for the exploratory clinical outcomes, including the separate analysis of each component of the main secondary outcome, was corrected by the False Discovery Rate method