Treatment option for diaphragm dysfunction after cardiac surgery: a review and a clinical case

INTRODUCTION. Dysfunction of diaphragm postoperatively is associated with worsened quality of life and increased health care costs due to prolonged respiratory support and morbidity. After cardiac operations, dysfunction of diaphragm can take place in up to 10 % of patients but often remains underdiagnosed. At the same time, histologically revealed changes, such as muscle atrophy in the diaphragm, start within 12 hours of mechanical ventilation. The therapy of diaphragm weakness is not well established and has a limited efficacy. Current analytic review describes therapeutic option for treatment ventilator-induced diaphragm dysfunction with emphasis on electric neuromodulation of phrenic nerve. OBJECTIVE. To optimize respiratory function by bilateral electrostimulation of phrenic nerves on the neck level in patient with diaphragm dysfunction after cardiac operation. MATERIALS AND METHODS. 82-year-old female patient after elective aortic valve replacement was diagnosed with dysfunction of diaphragm and respiratory failure. These changes caused the weaning failure from respirator and led to prolonged ventilator support. On the 20, 22, 24 and 26 days of postoperative period we performed invasive bilateral phrenic nerve stimulation on the neck level for 10 minutes with ultrasound navigation. RESULTS. After electrical modulation of phrenic nerves, diaphragm excursion, detected by ultrasound, was improved. After four procedures, duration of spontaneous breathing trial increased from 1 to 12 hours. On postoperative day 30, the patient was successfully weaned from respiratory support and decannulated without recurrent respiratory failure. There were no any complications during procedure, it was well-tolerated and associated with emotional improvement. CONCLUSIONS. Phrenic nerve stimulation on the neck level can be a valuable option in selected patients with respiratory failure and difficulties with ventilator weaning.