Table 1. Demographic data of the patients and comparison of studied predictive factors depending on occurrence of difficult intubation.
Values are mean, standard deviation (SD) or number.
| Difficult intubation (n = 33) | Normal intubation (n = 167) | p-value | |
|---|---|---|---|
| Age (years) | 60 ± 8.4 | 61 ± 12 | 0.476 |
| Height (cm) | 174 ± 8 | 174 ± 7 | 0.147 |
| Weight (kg) | 95 ± 22.3 | 79.6 ±15 | 0.004 |
| Body Mass Index (kg/m2) | 31 ± 6 | 26 ± 5 | 0.006 |
| Thyromental height; mm ± SD | 46 ± 10 | 54 ± 9 | 0.001 |
| Thyromental distance; mm ± SD | 93 ± 21 | 95 ± 18 | 0.37 |
| Sternomental distance; mm ± SD | 172 ± 33 | 179 ± 23 | 0.85 |
| Mallampati scale; | 0.24 | ||
| I | 16 | 94 | |
| II | 7 | 52 | |
| III | 6 | 14 | |
| IV | 4 | 7 | |
| Cormack & Lehane classification; | |||
| I | 12 | 112 | <0.001 |
| II | 7 | 43 | |
| III | 10 | 11 | |
| IV | 4 | 1 |
Logistic regression analysis revealed that only TMHT and Cormack-Lehane scale have significant impact on the occurrence of difficult intubation (Table 3, Fig 3). With every 1 mm increase in THMT, the risk of difficult intubation decreased by 7%. While the increase in Cormack—Lehane scale in 1 point is associated with a 3-fold increased risk of difficult intubation. Other factors, namely the thyromental distance, sternomental distance and Mallampati score turned out to be irrelevant to the occurrence of difficult intubation in developed statistical model.