Anesthesia-related unexpected cardiac arrest- What are we doing wrong on preoperative evaluation?

To the Editor, Preoperative risk stratification is recommended as part of any strategy to prevent perioperative cardiovascular complications. Most algorithms proposed by several international guidelines emphasize the assessment of preoperative cardiopulmonary fitness, or functional capacity (FC), as an important component of estimating patients’ risks for major cardiovascular morbidity and mortality. It is widely accepted that patients proceed directly to elective low and intermediate-risk noncardiac surgery if they are deemed capable of more than 4metabolic equivalents (METs) of activity without symptoms, even in the presence of stable heart disease or clinical risk factors. Regarding a case of cardiac arrest after anesthesia induction, we propose a reflection on preoperative cardiac risk evaluation. Informed consent for publication was obtained. A 63-year-old female, ASA III, with a history of obesity (BMI 31) and type 2 diabetes mellitus under insulin therapy and poor metabolic control, was scheduled for lumbar decompression surgery (intermediate-risk procedure). She attended a preanesthetic evaluation 2 months prior to surgery when her FC was assessed. Her exercise capacity was difficult to estimate because of leg motor deficit and pain, but she denied angina pectoris, dyspnoea on exertion, orthopnea, or any other symptom suggestive of heart failure. Physical examination and preoperative testing found little to note and she had a previous normal resting transthoracic echocardiogram (Table 1). Cardiovascular stratification scores were also used: Revised Cardiac Risk Index revealed a 6% 30-day estimated risk of myocardial infarction, cardiac arrest, or death. General anesthesia was induced with a target-controlled infusion (TCI) of remifentanil (effect-site concentration 2ng/ mL) and propofol (total of 80mg infused by TCI view mode),