High thoracic epidural anesthesia as the sole anesthetic for redo off-pump coronary artery bypass surgery

Abstract

CASE REPORT An obese, 69-year-old woman suffering from hypertension, diabetes, and chronic obstructive pulmonary disease with seasonal wheezing presented to the hospital with progressive worsening of breathlessness and chest pain on exertion. She weighed 72 kg, her height was150 cm, and her body mass index was 32. She was not a smoker and did not give a history suggestive of sleep apnea. She was admitted to the hospital with unstable angina (grade III, the Canadian Cardiovascular Society grading of angina of effort) and was started on medical therapy for the control of angina. The patient gave a history of seasonal bronchospasm and was being treated with nebulization with salbutamol and ipratropium. Her vital signs on admission were as follows: heart rate 90 beats/min, blood pressure 180/ 100 mmHg, respiratory rate 22/min, and transcutaneous oxygen saturation 95% on room air The pulmonary function tests showed moderate, reversible airflow obstruction with no restriction. Her forced vital capacity, forced expiratory volume in one second, forced expiratory volume and forced vital capacity ratio were 1.1 L, 0.72 L, and 63.9%, respectively, which increased 15% after 2 puffs of salbutamol inhalation. Her other medications consisted of amlodipine, 5 mg once daily; aspirin, 100 mg once daily; human insulin, thrice daily according to her blood sugar; and ranitidine, 150 mg thrice daily. The laboratory tests showed a hematocrit of 33%, white cell count of 9,000 CU/MM, and platelet count of 250,000 CU/MM. Blood urea nitrogen was 20 mg/dL and serum creatinine 1.0 mg/dL. The arterial blood gases were unremarkable except for PCO2 of 42 mmHg. The chest radiograph showed prominent bronchovesicular markings. The patient had undergone coronary artery bypass grafting 7 years ago, wherein the left internal mammary artery (LIMA) and radial artery were used to make a “T” anastomosis and grafts to the left anterior descending artery (LAD), ramus