Ricome et al evaluated the impact of various factors on the ability of external cooling to achieve hypothermia following a cardiac arrest. These can help to identify a patient who may be a candidate for internal cooling. The authors are from Cochin Hospital in Paris.


Patient selection: comatose survivor of a cardiac arrest


Endpoint: temperature < 34°C within 12 hours of ICU admission (measuring core body temperature with a bladder probe)


Factors associated with a failure of external cooling to achieve endpoint:

(1) early coronary angiography intervention (performed prior to ICU admission)

(2) higher body weight

(3) delay between collapse and the start of cooling

(4) a higher body temperature at the time of ICU admission



• In the implementation breakpoints for body weight are > 90 kg and > 70 kg (see Figure 3).

• In the implementation the breakpoint for body temperature is > 36°C. The definition of hypothermia varies. In this paper hypothermia is < 34°C.

• The time from collapse to start of cooling was 1.8 to 3.3 hours in the successful group and 2.1 to 3.7 hours in the failure group (Table 1). > 3 hours will be used in the implementation.


Factors associated with success of external cooling:

(1) early hemodialysis (within first 12 hours)

(2) male


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