Heart pacing revives victims of cold exposure

NEW YORK May 26 (Reuters) Two people found unconscious in very cold conditions were revived using an external pacemaker to speed up their heart rate, among other measures, according to a new report.

''Transcutaneous pacing as a method of increasing blood pressure may be helpful in the resuscitation of profoundly hypothermic patients,'' Dr Jeffrey D Ho told Reuters Health.

''Although previously held beliefs would speak against this practice ... old practices always need reevaluation.'' Ho, from Hennepin County Medical Center in Minneapolis, Minnesota, and his associates explain that it has been thought that trying to speed up a heart that is beating slowly because of hypothermia could trigger an irregular, chaotic rhythm.

However, this may not necessarily be so, based on the two cases they describe in the Annals of Emergency Medicine.

The first patient, an 80-year-old man, was found lying in his kitchen with the door open and ''exposed to the external elements.'' He was ''very cold to the touch'' and his pulse was weak and slow at only 30 beats per minutes.

Once he was in the emergency department, normal resuscitation measures for victims of hypothermia were started but his heart rate and blood pressure remained low. A reasonable blood pressure is necessary for rewarming procedures to be effective, so the team placed external pacer pads on him and began pacing his heart.

This restored his heart rate to 80 beats per minute, which was successfully maintained for the duration of his treatment in the emergency room while he was being rewarmed.

After a stay in the ICU and a course of rehabilitation, the man was sent home in satisfactory condition.

The second patient, a 54-year-old woman, was founding lying unconscious outside her home and was ''so cold that no temperature could be obtained.'' Because of her persistently low blood pressure and slow heart rate, a decision was made while she was being transported to the emergency department to begin external pacing.

The transcutaneous cardiac pacing restored her pulse and blood pressure to normal, and eventually she became fully alert within 12 hours of admission to the intensive care unit, the researchers say.

She was discharged home after three days with no neurological deficits.

''One should not necessarily conclude anything from a case series of two,'' Ho cautioned.

However, he concluded, ''Based on my experience and the particular cases before me, I would try pacing again.'' The strategy is ''a novel solution to a difficult problem'' and it did not appear ''to cause any untoward risk or outcome to these patients.'' REUTERS KN VC0906