Relationship of Preoperative Thyroid Status with Outcomes of Patients Undergoing Cardiac Surgery Under Cardiopulmonary Bypass

Abstract

INTRODUCTION: Symptoms of hypothyroidism are often subtle and are easily overlooked specially in patients with a heart disease and symptoms are thought to be from the existing cardiac condition. There is a consensus that patients with known hypothyroidism should have thyroid screening before any major surgery including cardiac surgery and if indicated should be made euthyroid before surgery. AIMS AND OBJECTIVES: To study the correlation of thyroid function test status with postoperative course and outcome (total duration of hospital, duration of ICU stay, hours of mechanical ventilation and in hospital mortality). MATERIAL AND METHODS: This prospective study recruited 151 patients who underwent cardiac surgery under cardiopulmonary bypass, TSH was measured and compared with outcome in these patients. RESULTS: Hours of mechanical ventilation (35.20 ± 20.1 Vs 110.61 ± 71.9 hours), ICU stay (3.3 ± 2.30 vs 5.9 ± 5.56 days) and hospital stay (16.7±4.21 days vs 21.1 ± 6.95 days) was significantly less in euthyroid than patients whose TSH was raised before surgery , also postoperative in hospital mortality was more in patients with raised TSH preoperatively. CONCLUSION: We concluded that patients with Subclinical hypothyroidism (SCHT) and Overt Hypothyroidism (OH) planned for cardiac surgery on cardiopulmonary bypass should be treated and those on levothyroxine replacement should have fair control before undergoing surgery. Keywords: Subclinical Hypothyroidism [SCHT], Overt Hypothyroidism [OH], Cardiopulmonary Bypass, Atrial Fibrillation [AF].