Table 4.
Major Outcomes and Confounding Factors during the Cooling Period.
| Control | Magnesium | P | |
|---|---|---|---|
| Ambient Temperature (°C) | 23.5 ± 1.4 | 23.0 ± 1.6 | 0.444 |
| Relative Humidity (%) | 27 ± 6 | 30 ± 5 | 0.462 |
| Arm Gradient at Cooling (°C) | 4.5 ± 3.1 | 4.1 ± 1.6 | 0.295 |
| Bolus - to - Shivering Interval (min) | 136 ± 40 | 115 ± 26 | 0.266 |
| Mean Arterial Pressure (mmHg) | 106 ± 10 | 113 ± 11 | 0.001 |
| Heart Rate (bpm) | 70 ± 11 | 71 ± 9 | 0.44 |
| SaO2 (%) | 98 ± 2 | 96 ± 3 | 0.003 |
| Respiratory Rate (breaths per min) | 17 ± 5 | 17 ± 4 | 0.653 |
| End-Tidal CO2 (mmHg) | 39 ± 5 | 41 ± 3 | 0.010 |
| Serum [magnesium] (mmol·(L-1) | 0.83 ± 0.06 | 2.22 ± 0.35 | 0.0001 |
| Total Lactated Ringer's (L) | 3.2 ± 2.4 | 2.9 ± 1.1 | 0.715 |
| Cooling rate (°C·hr-1) | 1.2 ± 0.3 | 1.1 ± 0.4 | 0.501 |
| Thermal Comfort (VRS) | 2 ± 2 | 1 ± 1 | 0.545 |
| Mean Skin Temperature (°C) | 31.0 ± 0.3 | 31.0 ± 0.2 | 0.983 |
| Core Temperature (°C) | 36.6 ± 0.3 | 36.3 ± 0.4 | 0.040 |
| Gain of Shivering (ml·min-1·°C-1) | 437 ± 289 | 573 ± 370 | 0.344 |
Values above the line were first averaged over the cooling period and then averaged among the volunteers; values below the line are at the shivering threshold. "Bolus-to-shivering interval" indicates the time elapsed between the initiation of the drug bolus infusion and the shivering threshold. Data are presented as means ± SDs. VRS = verbal rating score.