Case of the Month #12

Andy Martin
Lucy Priestner

A 65 year old woman has a cardiac arrest at home. She is in VF and receives 2 DC shocks by the paramedics before return of spontaneous circulation (ROSC) is established. She is intubated at the scene and is taken to her local hospital.

She lives with her partner, but at this time no further information about her past medical history is known.

After arriving at the hospital, what are the next steps in managing this patient?

Immediate treatment
  • Airway and breathing
    • Control oxygenation (avoiding hyperoxia) with target oxygen saturations between 94-98%1
      • Aim for normocarbia 1
      • Protective lung ventilation (TV 6-8mL/kg IBW and PEEP 4-8cm H20)1
      • Nasogastric tube (NGT) to decompress stomach and prevent diaphragm splinting
      • Adequate sedation to reduce oxygen consumption
      • If using neuromuscular blockade, consider continuous EEG to detect seizure activity
      • Chest X-ray (CXR) to check endotracheal tube position, NGT, central venous catheter position and complications from CPR e.g. pneumothorax from rib fractures
    • Circulation
      • Maintain SPB >100mmHg1
      • 12- lead ECG
      • Consider arterial line insertion for blood pressure and blood gas monitoring
      • Consider central venous catheter insertion to facilitate vasopressor or inotropic agent delivery
Diagnosis
  • Those with STEMI/ new LBBB should proceed to coronary angiogram +/- PCI immediately1
    • If 12 lead ECG does not suggest STEMI/ new LBBB but cardiac risk factors are present, there should be a discussion with cardiology re: coronary angiogram +/- PCI – aim should be to undergo this within 2 hours of initial event
    • If cardiac cause unlikely or angiography identifies no cause, consider CTB +/- CTPA and treat accordingly1
Optimising recovery/ critical care management
  • Temperature control
    • Targeted Temperature Management (TTM)2, previously known as therapeutic hypothermia, of 32-36oC degrees for ≥ 24h with prevention of fever (temperature >37.5oC) is suggested to be neuroprotective.1
    • TTM should be considered in OHCA survivors who remain unresponsive after ROSC
    • Shivering should be treated with adequate sedation +/- neuromuscular blockade.
    • Rewarm by 0.25-0.5 degrees oC/hour after 24 hours of TTM to normothermia1
    • Contraindications to TTM: severe systemic infection, pre-existing medical coagulopathy, cardiac dysrhythmias.1
  • Optimise haemodynamics
    • Target MAP/ SBP to achieve adequate urine output (0.5-1ml/kg/hr), with a normal/ decreasing plasma lactate1,3
    • Bradycardias associated with induced hypothermia ≤40 bpm may be left untreated (as long as BP and lactate are adequate)
    • Some centres use intra-aortic balloon pumps (IABP) in patients with cardiogenic shock – however, IABP-SHOCK II trial failed to show improvements in 30-day mortality
    • Consider implantable cardioverter defibrillator (ICD) placement in patients with significant left ventricular dysfunction or persistent ventricular arrhythmias >24h after primary coronary event (in most circumstances, this will be once the patient has been discharged from the critical care unit).1
  • Normoglycaemia
    • Aim blood ≤10 mmol/L and avoid hypoglycaemia.1
    • Do not implement strict glucose control as this increases risk of hypoglycaemia and associated complications
  • Diagnose/ treat seizures
    • Routine seizure prophylaxis is not recommended1
  • Echo
    • To optimise cardiac output and estimate myocardial recovery.
  • Delay prognostication for ≥72hrs after rewarming
    • Neurological prognostication remains a challenge and should involve combining results of the following: physical examination (particularly pupillary response, corneal reflex and best motor response), electroencephalogram (EEG), neuroimaging of CT or MRI, somatosensory evoked potentials (SSEPs) and neurone-specific enolase (NSE) levels (if available).

What does the post cardiac arrest syndrome comprise of?

  • Post- cardiac arrest brain injury
    • Coma, seizures, myoclonus, varying degrees of neurocognitive dysfunction and brain death
  • Post- cardiac arrest myocardial dysfunction
    • Common after cardiac arrest but typically starts to recover by 2-3 days
  • Systemic ischaemia/ reperfusion response
    • Clinically manifests as ARDS, acute renal failure, refractory shock, and disseminated intravascular coagulopathy.
  • Persistent precipitating pathology
    • This may require separate direct therapy dependent on aetiology

Key take home messages