A low-tech and no-cost approach to induce mild hypothermia in postcardiac arrest patients

Backgrounds and goals

Mild induced hypothermia (MIH) has become a standard in neuroprotective treatment for anoxic brain injury after cardiac arrest. Different surface cooling protocols have been successfully used [1].

Materials and methods

We implemented MIH by use of ice-water-soaked towels over the torso and legs in combination with sedation/muscle paralysis to avoid shivering after prehospital cardiac arrest in patients, age 15–80 years, with persistent coma and lack of cardiogenic shock. The target temperature (33 ± 1°C) was maintained for 12–24 hours. We evaluated the feasibility of our protocol.

Results

From June 2002 to October 2003 we have treated 30 patients. The median age was 52 years (15–77 years). In 58% the initial rhythm was ventricular fibrillation. While 26 patients received MIH after the protocol, three patients were impossible to cool to target temperature. In one patient MIH had to be withdrawn due to persistent malignant arrhythmias. The median temperature course of the 26 patients in which MIH was successfully completed is shown in Fig. 1.

Figure 1

Median temperature course of 26 MIH-treated patients.

The mean time to reach the target temperature was 4.5 hours (0–12 hours). MIH was maintained for a median 13 hours (4–26 hours). The rewarming period to 37°C took a median of 8.75 hours (3–21.5 hours). MIH treatment was followed by fever (> 37.9°C) in 23 patients (88%).

Conclusions

MIH by use of our external cooling protocol is feasible, simple and inexpensive. However, surface cooling is tardy, imprecise and in some patients unsuccessful.