Bradycardia

• Hypoxia (arguably the most important cause)


• Neuraxial block e.g. high spinal and loss of cardioaccelerator nerves at T1-T4


• Drugs
• Opioids (fentanyl, remifentanil, morphine)
• NMBA (vecuronium, 2^nd dose of suxamethonium)
• Volatile anaesthetics (enflurane > isoflurane)
• Vasopressors (reflex bradycardia from use of metaraminol or phenylephrine)
• Neostigmine (without glycopyrrolate)
• Pre-existing β-blockade or digoxin therapy

• Eye surgery due to the oculocardiac reflex
• Laparoscopy from pneumoperitoneum or tension on vagally innervated structures e.g. mesentery
• Cervical or anal dilatation
• Airway manipulation

• Normal bradycardia e.g. athlete
• Ischaemic cardiac disease or arrhythmia
• Raised ICP
• Hypothermia
• Hypothyroidism
• Hyperkalaemia

• Immediate management follows that of the above-linked guidelines from the Resus Council and AAGBI, which are similar albeit not identical

Bradycardia is an anaesthetic emergency and I would seek senior anaesthetic support as well as making a rapid but thorough assessment of the patient

• Stop any surgical stimulus
• Ensure oxygen delivery is occurring from the breathing circuit


• If no pulse, severe hypotension or non-sinus bradycardia then immediately give atropine 500mcg IV
• If pulsed sinus bradycardia, proceed with an ABCDE approach:

1. Ensure position and patency of the airway device, and that the capnograph trace is compatible with a patent airway


2. Ensure adequate oxygenation and ventilation
• Check chest symmetry, rate, breath sounds, SpO₂, measured VT_exp and EtCO₂
• Includes checking the airway pressure using the reservoir bag & APL valve for <3 breaths


3. Administer positive chronotopic agent du jour
• Options include glycopyrrolate, ephedrine, adrenaline or isoprenaline
• One needs to consider the cause of the bradycardia (see list above) and remedy it accordingly
• Consider transcutaneous pacing


4. Maintain suitable depth of anaesthesia and adequate analgesia

• Disposition will depend on the cause of the bradycardia, the success in correcting it and how far through the operation it occurs
• May need to go to the cardiac catheter lab for transvenous pacing
• May need to go to CCU/ICU post-operatively


• Document in the patient's notes
• Complete critical incident form
• Inform the patient of the events