Cardiac Advanced Life Support

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The first five minutes of a CALS arrest. Compressions can be held for up to 60 s while the rhythm is treated, and the chest should be open within 5 min of the arrest
Figure 1 The first five minutes of a CALS arrest. Compressions can be held for up to 60 s while the rhythm is treated, and the chest should be open within 5 min of the arrest

Indications

  • Arrest after cardiac surgery via median sternotomy ⇒ follow CALS instead of the standard ALS algorithm
  • Emergency resternotomy is part of the arrest management within 10 days of the last operation; after day 10 it’s a senior clinician’s decision
  • Most arrests happen early, within 24 hours of surgery (up to half within the first 3 hours of ICU admission), and survival is much better than for arrests elsewhere (around 80%)
    • Usually the arrest is preceded by deterioration, but it can happen in a previously stable patient

Why CALS is Different

  • The common causes are surgical (tamponade, haemorrhage) or electrical (VF, pacing failure), so they are usually reversible by defibrillation, pacing or reopening the chest
  • External compressions are likely ineffective with tamponade, tension pneumothorax or massive haemorrhage, hence the emphasis on rapid resternotomy
    • Prolonged external compressions can also damage thoracic structures early after surgery (e.g. grafts, valves)
    • Internal massage is generally more effective than external compressions
  • Full-dose adrenaline risks a hypertensive crisis and graft disruption once sinus rhythm returns, so only small doses are used (see Medicines)

Team Roles

  • Six key roles, each allocated to a trained team member and rehearsed regularly:
    1. Team leader: runs the protocol and makes sure every role is filled
    2. ICU coordinator: a senior ICU clinician who prepares for resternotomy as soon as the arrest is called, manages the extra staff and calls for expert help
    3. Resternotomy team: generally two staff
    4. Resternotomy trolley
    5. Defibrillation and pacing
    6. Airway and breathing
  • CALS-ANZ has no dedicated drugs role, which is different to the UK CALS protocol (via LITFL) where the six roles are external cardiac massage, airway and breathing, defibrillation, team leader, drug administration and ICU coordinator
    • The UK drugs role stops all infusions and syringe drivers and gives amiodarone and anything else needed; in CALS-ANZ pausing and checking infusions is still a step, but it isn’t assigned to a named role

Initial Response

  • Confirm arrest and assess the rhythm
    • Check the arterial waveform and central pulse where available
  • Call for help (cardiothoracic surgeon, intensivist, theatre) and prepare for emergency resternotomy in parallel with resuscitation
  • Assess the airway and ventilation ⇒ manually ventilate the intubated patient
    • FiO₂ 1.0 and turn PEEP off
    • Exclude ETT problems, pneumothorax and haemothorax
    • If not intubated, ventilate with BVM or a supraglottic airway; intubation is best done once the chest is open or after ROSC
  • Pause all infusions and syringe drivers and check them for errors before restarting them one at a time
  • External compressions can be withheld for up to 60 seconds while delivering rapid rhythm-specific treatment:
Arrest RhythmCALS Response
Ventricular fibrillation or pulseless ventricular tachycardiaUp to three stacked shocks (200 J, 300 J, 320 J biphasic)
Start compressions if no ROSC within 10 s of the third shock
Amiodarone 300 mg after the third failed shock1
Asystole or severe bradycardiaIf epicardial pacing wires are present, pace in DOO mode2
Pulseless electrical activityIf paced, briefly pause the pacemaker to exclude underlying ventricular fibrillation
  • Commence compressions while waiting for emergency resternotomy
    • Don’t withhold compressions while setting up for resternotomy
    • Aim for a systolic of at least 60 mmHg on the arterial trace

Cloze

In CALS, external compressions can be withheld for up to 60 seconds while the rhythm is treated, and the chest should be reopened within 5 minutes of the arrest

Emergency Resternotomy

  • Should be completed by a trained team within 5 minutes of the onset of the arrest
    • Indicated if initial measures fail to restore ROSC, even if a surgical cause seems unlikely
  • Steps:
    1. Cut through the dressing and adhesive drape down to the sternal wires
    2. Cut the wires and remove them ⇒ this alone may relieve a tamponade
    3. Place the retractor just beneath the sternum, suction clot and identify where the grafts are
  • Internal massage: two-handed technique
    • Right hand flat over the apex and behind the heart (palm up), left hand flat on the anterior surface, then squeeze at 100/min with palms flat and fingers straight
    • Aim for a systolic of more than 60 mmHg on the arterial trace
    • After mitral valve surgery, don’t lift the apex with the right hand, since this risks posterior ventricular rupture
  • Internal defibrillation: 20 J, 30 J and 50 J with the internal paddles3
    • 5 J if on bypass

Medicines

  • Adrenaline to only be given under the direction of a clinician experienced in CALS and only in small doses (e.g. 50–100 mcg IV)
    • Full doses risk a hypertensive crisis and graft disruption once sinus rhythm returns, and adrenaline hasn’t been shown to improve outcomes after post-cardiac surgery arrest
  • Amiodarone 300 mg for refractory shockable rhythms after the three stacked shocks, but don’t delay resternotomy for it

Cloze

In CALS, adrenaline is only given under the direction of an experienced clinician, in small doses of 50–100 mcg IV

Reversible Causes

  • Specific to post-cardiac surgery:
    • Tamponade
    • Haemorrhage and hypovolaemia
    • Myocardial ischaemia (e.g. graft failure)
    • Tension pneumothorax and haemothorax
    • ETT problems
    • Pacing failure

Sources

Footnotes

  1. Each stacked shock is less likely to work than the one before (about 78%, 35% then 14%), so a fourth shock without intervening CPR isn’t recommended ↩

  2. The UK CALS protocol (via LITFL) instead uses DDD at maximum atrial and ventricular output and a rate of 100/min ↩

  3. CALS-ANZ only gives 20 J for internal defibrillation ↩

Disclaimer: These notes are for educational purposes only and are not medical advice. I do not claim copyright for the content or images unless otherwise stated. For concerns or changes, create a new issue on GitHub.

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