Unanticipated Difficult Laryngoscopy in a Diabetic Patient Undergoing Coronary Artery Bypass Graft Surgery
Difficult laryngoscopy has been shown to be more frequent in cardiac surgery versus general
surgery. In one study, the incidence of difficult laryngoscopy in cardiac surgery was almost
double that compared to general surgery patients.1 The incidence of difficult laryngoscopy is
also higher in diabetic patients, with an incidence reported to be as high as 30% in long-term
diabetics.2
In Singapore, the prevalence of diabetes mellitus in patients presenting for coronary
artery bypass grafting (CABG) is high and despite a seemingly normal airway examination
based on head and neck examination, one may encounter unexpected difficulties.
We present a 53-year-old man diagnosed with triple vessel coronary artery disease
scheduled for CABG. He weighed 64.4 kg, was 163 cm tall and had a body mass index
of 24.2. He had a significant 30-year history of juvenile onset diabetes with a fair blood glucose
control demonstrated by a recent HbA1C of 7.9%. He was on a subcutaneous insulin regiment
of Mixtard 34 units in the morning, 15 units at night, and oral Metformin 250 mg twice a day.
His complications related to diabetes include hypertension and ischemic heart disease.
He had suffered two previous myocardial infarctions that were treated with percutaneous coronary interventions. His pre-operative transthoracic echocardiogram showed a left ventricular
ejection fraction (LVEF) of 20% and he had multiple previous hospital admissions for congestive heart failure. His renal function was otherwise normal with an estimated glomerular filtration rate of 102 ml/min. He did not have retinopathy or neuropathy prior to surgery.
Diabetes Res Open J. 2017; 3(2): 39-41. doi: 10.17140/DROJ-3-134