Postoperative phrenic nerve palsy in patients with open-heart surgery.

We prospectively studied patients undergoing open-heart surgical procedures to evaluate the role of phrenic nerve palsy in the causation of the high incidence of pulmonary complications reported in these patients. Although atelectasis, or infiltrates, or both developed in the left lower lobe of 98% of the patients (43 of 44) with or without similar changes on the right side, only 5 (11%) of the 44 patients had diaphragmatic dysfunction following operation. In 1, the left phrenic nerve became inexcitable; 2 had paresis of the left hemidiaphragm, and 2 had paresis of the right hemidiaphragm. Although damage to the phrenic nerve can occur during open-heart operations, a relatively low incidence of this complication does not support it as the major cause of postoperative pulmonary complications.