Precipitous bradycardia induced by laryngoscopy in cardiac surgical patients

Abstract

We present three patients with severe ischaemic heart disease who developed profound bradycardia (heart rates of 15 beats.rain "~, 10 beats'rain -t and asystole) at the time of laryngoscopy and spraying of the trachea with topical lidocaine. All patients had received fentanyl 20-30 tzg-kg -j and pancuronlum 0.1-0.13 mg'fcg -t For over 40 years it has been appreciated by anaesthetists that the performance of laryngoscopy and intubation can be accompanied by reflex circulatory responses. With the introduction of the non-depolarizing muscle relaxants in the 1940's and 1950's it was realised that the shift in technique from intubation under deep planes of volatile anaesthesia to the lighter planes made possible by the use of relaxants could predispose the patient to the development of intubation-related arrhythmias, including bradyarrhythmias. 1Consequent upon the increase in understanding of the pathophysiology of isehaemic heart disease, there has been a shift in emphasis towards the importance of hypertension and taehyeardia associated with laryngoscopy and intubation and the subsequent development of myocardial ischaemia. ~ This emphasis has led to the underestimation of the degree and severity of bradycardia which can occur with laryngoscopy and intubation. Key wordsANAESTHESIA'. cardiac', COMPLICATIONS: bradycardia. We therefore would like to present three patients with severe cardiac disease who developed significant bradycardia at the time of laryngoscopy and spraying of the trachea and vocal cords with topical anaesthetic solution. Case reports Case IFifty-four-year-old 64 kg female, with a long past history of hypertension and ischaemic heart disease, was admitted to the coronary care unit with unstable angina. Her medication consisted of propranolol 320 mg daily, hydroehIorthiazide 25 mg daily, amiloride 5 mg daily and isordil 80 mg orally daily. She was commenced on intravenous nitroglycerine for chest pain which continued despite this therapy and was complicated by one episode of sinus arrest lasting six seconds. Coronary angiography revealed triple vessel disease and the patient was scheduled for urgent coronary artery bypass surgery.She was premedicated with morphine 7.5 mg IM, scopolamine 0.3 mg 1M and received 7 mg diazepam IV during insertion of arterial, venous and pulmonary artery catheters. At induction blood pressure (BP) was 150/80 mmHg, heart rate (HR) 48 bpm, mean pulmonary artery pressure (MPAP) 17 mmHg and pulmonary capillary wedge pressure (PCWP) 10 mmHg. Induction of anaesthesia was with fentanyl 1600 Ixg (25 Ixg' kg-~) pancuronium 8 mg and nitrous oxide with 50 per cent oxygen. Following induction her heart rate increased to 65 bpm and BP was 125/70 mmHg. After three minutes of ventilation, laryngoscopy and spraying of the cords with 1 mg-kg -~ of ten per cent lidocaine was followed by progressive bradyeardia to a minimum rate of l0 bpm, The BP fell to 75 mmHg systolic (Figure 1). A precordial thump was given and heart rate recovered to 75 bpm over the following 12 seconds. Subsequen...

Severe bradycardia during suspension laryngoscopy performed after tracheal intubation using a direct laryngoscope with a curved blade -A case report-

“…There are a few reports about bradycardia or asystole caused by direct laryngoscopy [6-9]. One factor in the occurrence of this phenomenon is the vagal reflex.…”

“…Remifentanil is an opioid widely used in anesthesia induction for the attenuation of hemodynamic responses but it carries the risk of causing severe cardiovascular depression, especially bradycardia [2-5]. Although activation of afferent parasympathetic nerve fibers during direct laryngoscopy may result in bradycardia and asystole, only a few instances of bradycardia or asystole during direct laryngoscopy for tracheal intubation have been reported [6-9]. We report a case of severe bradycardia in response to suspension laryngoscopy for laryngeal polypectomy after safe completion of tracheal intubation using a direct laryngoscope with a curved blade.…”

Asystole during Suspension Laryngoscopy: Case Report, Literature Review, and Prophylactic Strategies

“…is complication is documented in patients with severe cardiac disease or history of previous trauma with intracranial hypertension [3,4]. is review illustrates the case of a patient without such comorbidities who underwent suspension laryngoscopy and evolved with asystole.…”

Asystole following Reintubation during Suspension Laryngoscopy

“…This phenomenon is understood to be due to a sympathetic nervous system reflex causing an increase in plasma catecholamines [1]. Rarely, severe bradycardia and possible asystole can occur following laryngoscopy [2]. One previous report described asystole during suspension laryngoscopy after uneventful direct laryngoscopy [2].…”

“…Rarely, severe bradycardia and possible asystole can occur following laryngoscopy [2]. One previous report described asystole during suspension laryngoscopy after uneventful direct laryngoscopy [2]. This response has been attributed to direct activation of afferent parasympathetic nerve fibers, use of vagotonic opioid drugs, light anesthesia, and hypoxia-induced bradyarrhythmia [3].…”