Anaesthesia complications

Question 1

What are some anaesthesia complications?

Answer 1

• bradycardia
• tachycardia
• ventricular/atrial ectopic beats
• hypotension
• hypoxaemia

Question 2

What can cause bradycardia?

Answer 2

• drugs (volatile, alpha 2 agonist, induction agent, opioid)
• toxaemia (endogenous/exogenous)
• vagus
• heart problem e.g. hyperkalaemia
• hypoxia

Question 3

What can stimulate the vagus?

Answer 3

• tracheal, laryngeal, pharyngeal stimulation
• eyeball pressure
• visceral distention or inflammation

Question 4

Approach to brachycardia

Answer 4

• is output being compromised? (ABP & SPO2)
• is there a danger of ventricular fibrillation?
• why is it happening?
• check depth of anaesthesia, vagal tone causes, hypoxia, toxaemia, treat cause 1st if possible
• if alpha-2 induced use atipamezole
• consider anticholinergics: atropine or glycopyrrolate

Question 5

When to consider use of anticholinergics for bradycardia

Answer 5

• when you can’t figure out why they’re bradycardic
• will dramatically increase the hr and improve perfusion

Question 6

What can cause tachycardia?

Answer 6

• sympathetic stimulation, too ‘light’
• PaCO2, PaO2, pH abnormalities
• CNS disturbances
• low ABP, or cardiac dz
• drugs e.g. anticholinergics

Question 7

Approach to tachycardia

Answer 7

• is output being compromised (ABP & SPO2%)
• is there a danger of ventricular fibrillation?
• why is it happening?
• check depth of anaesthesia, CO2, et then consider an IV opioid or lidocaine or propranolol/esmolol
• vaporiser setting can be increased in addition to opioid
  – this increases unconsciousness but doesn’t block nociceptive signals going to the brain

Question 8

What can happen after giving fentanyl?

Answer 8

• can stop breathing so have to give breaths for 5 mins or so

Question 9

Commonest causes of ectopic beats

Answer 9

• circulating catecholamines (stress/pain/adrenaline)
• hypoxia or hypercapnia
• hypovolaemia or hypotension
• anaesthetic drugs
• myocardial inflammation or stimulation
• trauma
• CHF or HCM
• major organ dz e.g. intracranial dz

Question 10

Approach to ventricular/atrial ectopic beats

Answer 10

• is output being compromised? (ABP & SPO2%)
• are the VPCs multiform, in sequence or paroxysms?
• why is it happening?
• check depth of anaesthesia, CO2, etc then consider an IV opioid, lidocaine or propranolol/esmolol
  – consider an opioid IV to reduce stress associated with pain, if this doesn’t work give lidocaine injection
• vaporiser setting can be increased in addition to opioid

Question 11

Approach to hypotension

Answer 11

• check equipment (cuff size, cuff position, transducer, patency of cannula, fluid line)
• urine production? i.e. other crude indicators of output
• reduce volatile/inhalant agent (TIVA/PIVA)
• increase IVFT
• re-check ABP
• consider use of inotrope (dobutamine)
• consider use of vasopressor (norepinephrine)

Question 12

What is the commonest cause of slow recovery?

Answer 12

• hypothermia