Risk factors for intraoperative bradycardia during ear, nose, throat and maxillofacial surgery

Intraoperative bradycardia (IOB) is one of the most common cardiac arrhythmias observed in clinical anaesthetic practice. Controlled hypotension, as a strategy of lowering patient's blood pressure during anesthesia has been practiced for decades in head and neck surgery. The aim of our study was to determine the incidence and the risk factors for intraoperative bradycardia in maxillofacial, ear, nose and throat surgery, as well as to determine whether controlled hypotension affects the occurrence of IOB. The retrospective study included 2304 patients who underwent maxillofacial, ear, nose or throat surgery. We studied the influence of: sex, age, comorbidity, type of surgery, duration of anesthesia and controlled hypotension on the occurrence of IOB. IOB was registered in 473 patients (20.5%). Patients with controlled hypotension had IOB significantly more often than patients without controlled hypotension (33.9 vs 15.1%) (p = 0.000). The significant predictors of IOB were: age (OR = 1.158; 95% CI = 1.068-1.256; p = 0.000), sex (OR = 0.786; 95% CI = 0.623-0.993; p = 0.043), ischemic heart disease (OR = 2.016; 95% CI = 1.182-3.441; p = 0.010); ear surgery (OR = 1.593; 95% CI = 1.232-2.060; p = 0.000), anesthesia duration, (OR = 1.006; 95% CI = 1.004-1.007; p = 0.000) and controlled hypotension (OR = 2.204; 95% CI = 1.761-2.758; p = 0.000). IOB is common in maxillofacial, ear, nose and throat surgery, particularly in male, older age and patients with ishemic heart disease. The ear surgery, longer anesthesia duration and controlled hypotension raise the risk for occurrence of IOB.