3-12. Cardiac ischaemia

SJH Theatres and Anaesthetics
NHS Lothian

Objectives

If the patient is unconscious, signs of cardiac ischaemia primarily include: 

  • ST elevation or depression 
  • T wave flattening or inversion 
  • Arrhythmias, particularly ventricular 
  • Other haemodynamic abnormalities (hypo- or hypertension, tachy- or bradycardia) 
  • New or evolving regional wall motion abnormalities if echocardiography is used 

If the patient is conscious, symptoms may include chest pain, breathlessness, dizziness, nausea and vomiting. 

Have a high index of suspicion in patients with a pre-existing history or risk factors for cardiac ischaemia.

START

❶ Call for cardiac arrest trolley and 12-lead ECG machine.

❷ Ensure adequate oxygenation and anaesthesia/analgesia.

❸ Treat haemodynamic instability (Box A).

❹ Apply CM5 continuous ECG monitoring (Box B). Obtain a 12-lead ECG as soon as possible.

❺ If ischaemia does not resolve:

  • Call for help. Inform theatre team of problem. Stop or rapidly complete the surgery.
  • Start glyceryl trinitrate (GTN) (Box C).
  • EXTREME CAUTION with GTN if the patient is hypotensive.

❻ Consider invasive arterial blood pressure monitoring.

❼ Treat electrolyte abnormalities particularly potassium, magnesium and calcium.

❽ Treat anaemia aiming for haematocrit >30%.

  • CAUTION – beware volume overload especially in heart failure.

❾ If persistent ST elevation is present, consider need for anticoagulation, anti-platelet therapy and revascularisation in consultation with cardiology and surgical teams.

 

 

Box A: HAEMODYNAMIC INSTABILITY

  • Cardiac arrest → 2-1  
  • Hypotension → 2-4 
  • Hypertension → 2-5 
  • Bradycardia → 2-6 
  • Tachycardia →  2-7  

Box B: CM5 ECG CONFIGURATION

  • Right arm (red) lead over upper right sternum. 
  • Left arm (yellow) lead 5th intercostal space under left nipple. 
  • Indifferent (green or black) lead on left shoulder. 

Box C: GLYCERYL TRINITRATE (GTN) DOSE

  • Consider sublingual administration. 
  • i.v.: 1 mg.ml-1 solution – start at 0.1ml.kg-1.hr-1, titrate against response. 
  • NOT RECOMMENDED IN CHILDREN.

Box D: AFTER THE EVENT

Admit to critical care environment and consult cardiology 

Maintain head up position if practicable 

Obtain serial 12-lead ECGs and cardiac enzymes 

 

Editorial Information

Last reviewed: 31/08/2019

Author(s): The Association Of Anaesthetists of Great Britain & Ireland 2019. https://anaesthetists.org/Quick-Reference-Handbook. Subject to Creative Commons license CC BY-NC-SA 4.0. You may distribute original version or adapt for yourself and distribute with acknowledgement of source. You may not use for commercial purposes. Visit website for details. The guidelines in this handbook are not intended to be standards of medical care. The ultimate judgement with regard to a particular clinical procedure or treatment plan must be made by the clinician in the light of the clinical data presented and the diagnostic and treatment options available..

Version: 2