Table 2.
Parameter estimate in ANOVA models for flow speed (log-transformed).
| Model A |
Model B |
Model C |
Model D |
|||||
|---|---|---|---|---|---|---|---|---|
| 15°C |
22–24°C |
37°C |
Overall model |
|||||
| (n = 240) |
(n = 250) |
(n = 130) |
(n = 620) |
|||||
| Estimate (SE) | P-value | Estimate (SE) | P-value | Estimate (SE) | P-value | Estimate (SE) | P-value | |
| Intercept (control) | 6.12 (0.05) | <0.0001 | 7.28 (0.05) | <0.0001 | 7.61 (0.08) | <0.0001 | 7.73 (0.07) | <0.0001 |
| Fentanyl | 0.22 (0.06) | 0.0004 | 0.09 (0.05) | 0.05 | 0.37 (0.12) | 0.002 | 0.15 | 0.0002 |
| −0.04 | ||||||||
| Dexmedetomidine | 0.12 (0.04) | 0.008 | −0.37 (0.06) | <0.0001 | −0.32 (0.12) | 0.008 | −0.57 (0.09) | <0.0001 |
| Isoflurane | −0.02 (0.06) | 0.71 | −0.40 (0.06) | <0.0001 | −0.36 (0.11) | 0.002 | −0.51 (0.10) | <0.0001 |
| Drug–drug interaction | ||||||||
| Iso and fen | −0.59 (0.09) | <0.0001 | – | – | −0.62 | 0.0002 | −0.30 (0.09) | 0.002 |
| −0.16 | ||||||||
| Iso and dex | – | – | 0.37 (0.09) | <0.0001 | 0.39 (0.16) | 0.02 | 0.75 (0.12) | <0.0001 |
| Fen and dex | – | – | – | – | −0.47 | 0.0046 | – | – |
| −0.16 | ||||||||
| Fen and dex and iso | – | – | – | – | 0.69 (0.23) | 0.003 | – | – |
| Temperature | ||||||||
| 15°C | – | – | – | – | – | – | −1.54 (0.08) | <0.0001 |
| 22–24°C | – | – | – | – | – | – | −0.47 (0.08) | <0.0001 |
| Drug and temperature Interactions (reference category: 37°C) | ||||||||
| 15°C and dex | – | – | – | – | – | – | 0.62 (0.11) | <0.0001 |
| 22–24°C and dex | – | – | – | – | – | – | 0.20 (0.11) | 0.054 |
| 15°C and iso | – | – | – | – | – | – | 0.39 (0.12) | 0.001 |
| 22–24°C and iso | – | – | – | – | – | – | 0.14 (0.12) | 0.23 |
| 15°C and fen/iso | – | – | – | – | – | – | −0.22 (0.11) | 0.043 |
| 22–24°C and | – | – | – | – | – | – | 0.24 (0.11) | 0.023 |
| Fen/ISO | ||||||||
| 15°C and dex/iso | – | – | – | – | – | – | −0.61 (0.15) | <0.0001 |
| 22–24°C and dex/iso | – | – | – | – | – | – | −0.37 (0.15) | 0.013 |
Note: Log-transformed flow speed was used in the models. At each temperature, a full regression model including three two-way interactions and three-way interactions among fentanyl (fen), dexmedetomidine (dex), and isoflurane (iso) were performed first, and then the non-significant terms were dropped in the final regression model presented in the table. The overall model used all data and included the main temperature and drug effects and all the significant interactions, with temperature 37°C as the reference category.