Positive end-expiratory pressure in the management of the patient with a postoperative bleeding heart.

This prospective study involves 406 consecutive adults who had heart operation with extracorporeal circulation. Fifteen patients (3.7%) bled at the rate of 200 ml per hour or more in the postoperative period. Thirteen of the 15 patients who bled had undergone coronary artery operation. After all clotting factors and, when applicable, hypertension had been checked and corrected, positive end-expiratory pressure (PEEP) was used in managing the bleeding of these patients. Before institution of PEEP, the average bleeding was 330 ml per hour for one to five hours. After PEEP was instituted in the 11 patients in whom bleeding was controlled, an average output of 25 ml per hour for one to ten hours was recorded. Patients were kept on PEEP for 5 to ten hours. In 7 patients hemorrhage was controlled with 10 cm H2O of PEEP; 4 required 15 cm of PEEP to stop bleeding; 3 were explored for continuous bleeding on 15 cm of PEEP; and 1 was explored because of hypotension on 15 cm of PEEP. In 11 of the 15 patients who bled postoperatively (73%), operation was avoided by judicious use of PEEP. We believe that PEEP increases mediastinal pressure and that the overdistended lung can obliterate some bleeding in the mediastinum, thus controlling bleeding in many of these patients.