Table 1.
Demographic and intraoperative data
| Variables | Group Z (n = 19) | Group P (n = 18) | P value |
|---|---|---|---|
| Age (y) | 46.9 ± 14.5 | 50.9 ± 16.6 | 0.439 |
| Sex (female:male) | 12:7 | 8:10 | 0.260 |
| Weight (kg) | 64.7 ± 10.3 | 63.5 ± 14.0 | 0.773 |
| Height (cm) | 161.9 ± 10.6 | 162.6 ± 10.0 | 0.822 |
| Body mass index (kg/m2) | 24.7 ± 2.9 | 23.8 ± 3.5 | 0.423 |
| Hypertension | 3 (15.8) | 3 (16.7) | 1.000 |
| Diabetes | 0 (0.0) | 1 (5.0) | 0.305 |
| Diagnosis | 0.213 | ||
| Tumour | 12 (63.2) | 9 (50.0) | |
| Myelopathy | 2 (10.5) | 5 (27.8) | |
| Fracture | 1 (5.3) | 3 (16.7) | |
| Others | 4 (21.1) | 1 (5.6) | |
| Operation site | 0.338 | ||
| Cervical | 3 (15.8) | 6 (28.6) | |
| Thoracic | 8 (42.1) | 9 (50.0) | |
| Lumbar | 6 (31.6) | 2 (11.1) | |
| Sacral | 2 (10.5) | 1 (5.6) | |
| Ambient temperature (°C) | 19.0 [17.5–21.5] | 18.5 [17.5–19.8] | 0.537 |
| Preoperative forehead skin temperature (°C) | 36.5 [36.4–36.6] | 36.6 [36.5–36.7] | 0.161 |
| Preoperative skin temperature difference between forearm and fingertip (°C) | 3.6 [0.8–4.9] | 3.8 [1.1–4.9] | 0.927 |
| Operation time (min) | 208 [166–244] | 194 [158–249] | 0.506 |
| Anaesthesia time (min) | 260 [221–309] | 250 [224–316] | 0.862 |
| Amount of administered propofol (mg) | 2000 [1603–2293] | 1705 [1300–2185] | 0.222 |
| Amount of administered remifentanil (µg) | 2000 [1600–2386] | 1900 [1175–2350] | 0.437 |
| Amount of administered crystalloids (ml) | 1600 [1200–1975] | 2000 [1438–2438] | 0.084 |
| Estimated blood loss (ml) | 400 [262–488] | 550 [300–775] | 0.319 |
| Transfusion | 2 (10.5) | 1 (5.6) | 0.585 |
| Urine output (ml) | 787 ± 564 | 674 ± 496 | 0.491 |
Data are presented as mean ± standard deviation, median [interquartile range], or number (%).
Patients in Group Z were mechanically ventilated with zero end-expiratory pressure, while those in Group P were mechanically ventilated with 10 cmH2O positive end-expiratory pressure.