Table 1.
Clinical Characteristics of Patients with Difficult and Non-Difficult Laryngoscopy, and Discrimination Power (AuROC) Under Univariable Analysis
| Prognostic Factor | All (n=617) | Difficult Laryngoscopy (n=83) | Non-Difficult Laryngoscopy (n=534) | P-value | AuROC (95% CI) | |||
|---|---|---|---|---|---|---|---|---|
| n | % | n | % | n | % | |||
| Mean (±SD) | Mean (±SD) | Mean (±SD) | ||||||
| Characteristic | ||||||||
| Age (year), mean (SD) | 68.66 (±17.61) | 66.99 (±17.01) | 68.92 (±17.70) | 0.335 | 0.449 (0.385–0.512) | |||
| Male gender | 349 | 56.56 | 53 | 63.86 | 296 | 55.43 | 0.155 | 0.542 (0.486–0.598) |
| Glasgow coma scale | ||||||||
| 3–8 | 49 | 7.94 | 6 | 7.23 | 43 | 8.05 | 0.631 | 0.525 (0.477–0.573) |
| 9–12 | 105 | 17.02 | 11 | 13.25 | 94 | 17.60 | ||
| 13–15 | 463 | 75.04 | 66 | 79.52 | 397 | 74.34 | ||
| Traumatic Cause | 35 | 5.67 | 8 | 9.64 | 27 | 5.06 | 0.120 | 0.523 (0.490–0.556) |
| Main Indication of intubation | ||||||||
| Failure oxygenation or ventilation | 391 | 63.43 | 56 | 67.47 | 335 | 62.73 | 0.716 | 0.470 (0.415–0.524) |
| Airway protection | 146 | 23.66 | 20 | 24.10 | 126 | 23.60 | ||
| Anticipated | 66 | 10.70 | 6 | 7.23 | 60 | 11.24 | ||
| Cash airway | 14 | 2.27) | 1 | 1.20 | 13 | 2.43 | ||
| Intubation Method | ||||||||
| Direct laryngoscopy | 512 | 82.98 | 67 | 80.72 | 445 | 83.33 | 0.533 | 0.513 (0.468–0.559) |
| Indirect laryngoscopy | 105 | 17.02 | 16 | 19.28 | 89 | 16.67 | ||
| Method of intubation | ||||||||
| RSI | 314 | 50.97 | 15 | 18.07 | 229 | 56.10 | <0.001 | 0.657 (0.608–0.705) |
| Sedation only, without paralysis | 229 | 37.18 | 62 | 74.70 | 167 | 31.33 | ||
| No-medical assisted | 69 | 11.20 | 3 | 3.61 | 66 | 12.38 | ||
| Others | 4 | 0.65 | 3 | 3.61 | 1 | 0.19 | ||
| Used of induction drug | ||||||||
| None | 73 | 11.83 | 6 | 7.23 | 67 | 12.55 | 0.038 | 0.547 (0.496–0.598) |
| Etomidate | 458 | 74.23 | 62 | 74.70 | 396 | 74.16 | ||
| Ketamine | 16 | 2.59 | 3 | 3.61 | 13 | 2.43 | ||
| Propofol | 28 | 4.54 | 1 | 1.20 | 27 | 5.06 | ||
| Others | 42 | 6.81 | 11 | 13.25 | 31 | 5.81 | ||
| Used of paralytic drug | ||||||||
| None | 301 | 48.78 | 68 | 81.93 | 233 | 43.63 | <0.001 | 0.311 (0.262–0.359) |
| Succinylcholine | 286 | 46.35 | 13 | 15.66 | 273 | 51.12 | ||
| Rocuronium | 30 | 4.86 | 2 | 2.41 | 28 | 5.24 | ||
| Mean number attempts | 1 (±0.7) | 2 (±1.46) | 1 (±0.4) | <0.001 | n/a | |||
| More than 1 attempts | 109 | 17.67 | 55 | 66.27 | 54 | 10.11 | <0.001 | 0.781 (0.728–0.834) |
| Failed intubation attempts | 108 | 17.50 | 55 | 66.27 | 53 | 9.93 | <0.001 | 0.782 (0.729–0.834) |
| Difficult intubation indicators | ||||||||
| Facial trauma | 17 | 2.76 | 9 | 10.84 | 8 | 1.50 | <0.001 | 0.547 (0.513–0.581) |
| Large incisor | 54 | 8.75 | 27 | 32.53 | 27 | 5.06 | <0.001 | 0.637 (0.586–0.689) |
| Beard or mustache | 28 | 4.54 | 13 | 15.66 | 15 | 2.81 | <0.001 | 0.564 (0.524–0.604) |
| Large tongue | 54 | 8.75 | 27 | 32.53 | 27 | 5.06 | <0.001 | 0.637 (0.586–0.689) |
| Limited mouth opening | 70 | 11.35 | 40 | 48.19 | 30 | 5.62 | <0.001 | 0.713 (0.658–0.768) |
| Short hyomental distance | 73 | 11.83 | 41 | 49.40 | 32 | 5.99 | <0.001 | 0.717 (0.662–0.772) |
| Short thyro-hyoid distance | 68 | 11.02 | 39 | 46.99 | 29 | 5.43 | <0.001 | 0.708 (0.653–0.763) |
| Poor neck mobility | 41 | 6.65 | 13 | 15.66 | 28 | 5.24 | 0.001 | 0.552 (0.512–0.593) |
| Presence of obstructed airway | 88 | 14.26 | 37 | 44.58 | 51 | 9.55 | <0.001 | 0.675 (0.620–0.730) |
| Mask seal | 75 | 12.16 | 25 | 30.12 | 50 | 9.36 | <0.001 | 0.604 (0.553–0.655) |
| Obesity | 79 | 12.80 | 35 | 42.17 | 44 | 8.24 | <0.001 | 0.670 (0.615–0.724) |
| Advanced age | 203 | 32.90 | 42 | 50.60 | 161 | 30.15 | <0.001 | 0.602 (0.545–0.660) |
| No teeth | 75 | 12.16 | 23 | 27.71 | 52 | 9.74 | <0.001 | 0.590 (0.540–0.640) |
| Stiff lung | 28 | 4.54 | 7 | 8.43 | 21 | 3.93 | 0.084 | 0.523 (0.491–0.554) |