[Cold-induced paralysis of the phrenic nerve in open-heart surgery (author's transl)].

Cold-induced injury of the phrenic nerve after pericardial cooling during open-heart surgery has already been reported, but the post-operative consequences and long-term course of this complication have seldom been documented. Fifty cases (6.6%) of phrenic nerve paralysis were observed in a series of 750 patients undergoing open-heart surgery with topical cooling of the pericardium for myocardial protection. As infectious and respiratory complications (including atelectasis, bronchial obstruction, pleural effusion, pneumonia and bacteriaemia) were significantly more frequent (p less than 0.05) in these patients, assisted ventilation and intensive care were significantly more prolonged (p less than 0.01). Long-term follow-up of 42 patients (mean: 14 months; range: 3-42 months) showed inconstant and often incomplete regression of the paralysis. The complication can easily be prevented by using a plastic insulation pad during pericardial cooling and cold cardioplegia.