Left lower lobe atelectasis and consolidation following cardiac surgery: the effect of topical cooling on the phrenic nerve.

Abstract

Retrospective and prospective analyses of chest radiographs of patients following coronary artery bypass surgery were undertaken. Left lower lobe pulmonary infiltrate and/or atelectasis developed in 13 of 40 (32.5%) patients who were operated upon without topical cooling of the heart with ice and in 77 of 122 (63.1%) patients in 1 group and 34 of 40 (85.0%) patients in another group who were operated upon with topical cooling of the heart with ice. This difference was highly significant (P < 0.001). Of the patients in 1 group in whom left lower lobe abnormality developed, 69.2% had paralysis or paresis of the left hemidiaphragm. Application of ice to the phrenic nerve apparently can lead to temporary paralysis of the left leaf of the diaphragm, with subsequent development of left lower lobe pulmonary infiltrate and/or atelectasis.