It’s wintertime in Minnesota and much of the upper Midwest. Although hypothermia does occur in this region, it’s not as common as you might think. And it does happen in just about any state (well, maybe no Hawaii). But when it does occur, it’s important to know what your options are for rewarming.
I put together a compilation of the average rewarming rates of commonly used techniques quite a few years ago. However, it’s time to update them based on some new data and a few new products.
| Warming Technique | Rate of Rewarming |
| Bladder lavage | no data probably < 0.5° C / hr |
| Passive external (blankets, lights) | 0.5 – 1° C / hr |
| Active external (lights, hot water bottle) | 1 – 3° C / hr |
| Bair Hugger (a 3M product, made in Minnesota of course!) | 2.4° C / hr |
| Hot inspired air in ET tube | 1° C / hr |
| Fluid warmer | 2 – 3° C / hr |
| GI tract irrigation (stomach or colon, 40° C fluid, instill for 10 minutes, then evacuate) | 1.5 -3° C / hr |
| Peritoneal lavage (instill for 20-30 minutes) | 1 – 3° C / hr |
| Cool Guard system | 1° C / hr |
| Cool Guard system with thoracic lavage | 2° C / hr |
| Cool Guard system with peritoneal lavage | 2.7° C / hr |
| Thoracic lavage (2 chest tubes, continuous flow) | 3° C / hr |
| Continuous veno-venous rewarming | 3° C / hr |
| Continuous arterio-venous rewarming | 4.5° C / hr |
| Mediastinal lavage (thoracotomy) | 8° C / hr |
| Cardiopulmonary bypass | 9° C / hr |
| Warm water immersion (Hubbard or therapy tank) | 20° C / hr |
One of the most important things to consider is the length of time for rewarming. Do the math using the numbers above! For most patients with severe hypothermia, it’s going to take several hours to rewarm. So make sure you are in a suitable location, such as an OR or ICU!
