Table 4.
Logistic Regression Analyses to Identify Independent Predictors of Inadvertent Hypothermia*
| Variable | Univariate Odds Ratio (95% CI) | P | Multivariable Adj. Odds Ratio 95% CI)* | P |
|---|---|---|---|---|
| Weight (kg) | 0.99 (0.98, 1.00) | 0.124 | 0.986 (0.972, 0.999) | 0.034 |
| Admission type | ||||
| Day surgery/inpatient | 0.60 (0.39, 0.90) | 0.015 | ||
| Surgical type | ||||
| Elective/emergency | 0.42 (0.21, 0.85) | 0.017 | 0.43 (0.21, 0.91) | 0.026 |
| Surgery | ||||
| Major/minor | 0.49 (0.30, 0.80) | 0.005 | ||
| Surgery site | ||||
| Chest (Y/N) | 2.14 (0.77, 5.92) | 0.143 | ||
| Abdomen (Y/N) | 0.40 (0.18, 0.88) | 0.023 | ||
| Anesthesia time (min) | 1.00 (0.99, 1.00) | 0.041 | ||
| Vol. warmed crystalloid (mL/kg) | 0.99 (0.96, 1.02) | 0.604 | ||
| Warmed fluids (Y/N) | 0.56 (0.37, 0.84) | 0.005 | ||
| Starting OT Temperature (°C) | 0.83 (0.73, 0.95) | 0.008 | 0.83 (0.71, 0.96) | 0.010 |
| Starting OT temperature (oC) | 0.060 | |||
| <21oC | 2.02 (0.92, 4.44) | 0.081 | ||
| 21–<23oC | 2.05 (1.13, 3.72) | 0.018 | ||
| 23–<25oC | 1.26 (0.73, 2.17) | 0.414 | ||
| ≥25oC | 1.00 | — | ||
| Intraoperative active warming | ||||
| Any form active warming (Y/N) | 0.58 (0.36, 0.95) | 0.031 | 0.42 (0.25, 0.70) | 0.001 |
| Bair Hugger (Y/N) | 0.52 (0.33, 0.83) | 0.006 | ||
| Intraoperative passive warming | ||||
| Occlusive dressing (Y/N) | 0.32 (0.13 0.70) | 0.004 | 0.35 (0.15, 0.85) | 0.020 |
| Intraoperative temperature monitoring (Y/N) | 0.45 (0.28, 0.73) | 0.001 | 0.49 (0.28, 0.85) | 0.011 |
*The multivariable analysis included only variables significant at P < 0.15 in univariate analysis, which are variables included in this table. Area under ROC curve (95% CI) for multivariable model was 0.71 (0.66, 0.76); 10-fold cross-validated area under ROC curve (95% CI) was 0.68 (0.63, 0.74).