Risk factors for intraoperative variations in blood pressure and cardiac dysrhythmia during thyroid surgery

Introduction/Objective Intraoperative variations in blood pressure and/or cardiac dysrhythmias (IOVBP/CD) represent one of the most common causes of morbidity and mortality in surgical patients. The aim of the study was to determine the incidence and risk factors for IOVBP/CD in thyroid surgery patients with comorbidities. Methods The study included 1,252 euthyroid patients with ASA 2 and ASA 3 status (American Society of Anesthesiologists - physical status classification) who underwent thyroid surgery. The following risk factors were examined: sex, age, body mass index (BMI), ASA status, admission diagnoses, type of operation, duration of surgery, time under general anesthesia, difficult intubation of trachea, and coexisting diseases- hypertension, cardiomyopathy, cardiac arrhythmias, angina pectoris, diabetes mellitus, kidney disease. The following intraoperative events were recorded: hypertension, severe hypertension, hypotension, and cardiac arrhythmias. We used Pearson X-2 square test, univariate, and multivariate logistic regression for statistical analysis. Results The majority of patients were female (86.3%). In 903 (72.1%) patients IOVBP/CD were detected. The most common problem was intraoperative hypertension (61.4%). Eight risk factors for IOVBP/CD were registered by univariate analysis: advanced age, ASA 3 status, BMI > 25 kg/m(2), duration of surgery, time under general anesthesia, hypertension, and cardiomyopathy as a coexisting disease. The multivariate regression model identified three independent predictors for IOVBP/CD: age, hypertension, and cardiomyopathy. Conclusion IOVBP/CD are common in thyroid surgery. The most common is intraoperative hypertension. Older age, hypertension, and cardiomyopathy as a coexisting disease are independent risk factors for IOVBP/CD.