Profound hypothermia has a high mortality if not treated with active rewarming. Most successful is central core rewarming. Many methods have been designed for this purpose: mediastinal irrigation, colon irrigation, peritoneal dialysis, and warm water via a Sengstaken-Blakemore esophageal tube.

A new esophageal tube was constructed for this study. The tube consists of a small, stiff and narrow inner tube, placed inside a larger thinwalled outer tube. Warm water (41-42°C) is circulated from a waterbath via the inner tube to the outer tube and then back to the waterbath. Five healthy mongrel dogs were anesthetized, intubated and made hypothermic. All dogs were paralyzed with pancuronium to eliminate shivering. The only fluid given was isotonic saline to compensate urine loss (50-75 ml/hour). At a core temperature below 30°C the esophageal tube was inserted, and rewarming started when temperatures had reached 27.1-24.7°C. Rectal and peripheral temperatures were monitored, and in 3 dogs blood temperature was also followed.

Up to the cardiac safety temperature (31°C) the blood temperature increased 4.6°C ± 0.79 (SD) (Fig. 1, whereas the rectal temperature rose 3.74°C ± 0.76 (SD) (Fig. 2). The peripheral temperature showed only a minor increase below a central core temperature of 30°C. This means that a secondary temperature decrease is eliminated with this method. No cardiac arrhythmias or other complications were noted. these results correspond to those with peritoneal dialysis (1), and show a greater temperature rise than with use of a modified Sengstaken-Blakemore tube (2). (Supported by the Danish Medical Research Council.)