Treatment Decisions

The following areas will be important in the on going management of a patient post ROSC:

Clinical neurological findings

The Advanced Life Support Task Force of the International Liaison Committee on Resuscitation (ILCOR) have recommended that the term Targeted Temperature Management (TTM) replace the historic term Therapeutic Hypothermia.

ILCOR recommend:

  1. Maintain a constant, target temperature between 32-36 degrees centrigrade for those patients in whom temperature control is used
  2. TTM is recommended for adults after OHCA with an initial shockable rhythm who remain unresponsive after ROSC
  3. TTM is suggested for adults after OHCA with an initial non shockable rhythm who remain unresponsive after ROSC
  4. TTM is suggested for adults after IHCA with any initial rhythm who remain unresponsive after ROSC
  5. If TTM is used, it is suggested that the duration is at least 24 hours

Most ITU clinicians in the UK now use 36 degrees centigrade as the TTM post cardiac arrest,

Myoclonic epilepsy is an indicator of very poor prognosis and is used by many physicians in the emergency department as an indicator to discontinue intensive ventilatory and circulatory supports [15,16].

However, case reports have contraindicated studies supporting this [8] – there is no definitive answer yet.

Pathophysiological factors (e.g. hypoglycaemia) and interventions (hypothermia, sedation, atropine administration) will affect the neurological exam and must be considered [3].

Absent pupillary light reflexes and an absent motor response to pain are of no value in prognosticating in the first few hours post-ROSC. By 72 hours, both are independently predictive of poor outcome [5].

Comorbidities and age

Advanced age probably increases the short-term mortality post-cardiac arrest but importantly does not predict neurological outcome in cardiac arrest survivors [ILCOR, 3].

Advanced age and a PEA rhythm combined are significant predictors of poor outcome [8].

Poor outcome in terms of survival is also associated with diabetes, sepsis prior to cardiac arrest, cancer, stroke, or being housebound before cardiac arrest.

These, again, have not been found to be reliable predictors of neurological outcome in those who do survive [3].

Type of arrest

A non-cardiac cause of arrest (e.g. hypoxia/hyperkalaemia as opposed to acute coronary syndrome), or asystole as the initial monitor trace on commencement of CPR, are unreliable as predictors of poor outcome [3].

Learning bite

Asystole as the initial rhythm on commencement of CPR is unreliable as a predictor of poor outcome [3].

Downtime, delay to start of CPR and quality of CPR

Several studies have shown an association between poor outcome and increasing time interval between collapse and start of CPR and/or from the start of CPR to return of spontaneous circulation [8].

A low ETCO2 of less than 10 mmHg during resuscitation (i.e. CO2 as a marker of cardiac output during CPR) is associated with poor outcome as is a low PaO2 after ROSC [3,8].

Learning bite

Increasing number of shocks or adrenaline doses correlate with poorer neurological outcome [8].

Early blood gas interpretation

pH on the first arterial blood gas (ABG) post-ROSC does not correlate with survival.

High lactate levels on post-ROSC blood gases have been associated with severe neurological impairment in one study – but a lactate has to be >16 to give 100% specificity for poor neurological outcome after ROSC [17].

CT/MRI Brain

This set of images shows a selection of CT scans obtained post ROSC. Click on the CTs to enlarge.

Fig 1: CT image of a normal brain Fig 2: CT image of a posterior fossa bleed Fig 3: CT image of extradural haematoma with overlying skull fracture

Conclusion

As a rule, post-ROSC comatose patients without significant pre-arrest co-morbidities should be taken to the ICU for supportive care, and their individual prognosis decided later by the intensive care team.

The best predictor of function we have is neurological outcome at 72 hours.

Delaying prognostication in individual patients until 72 hours post-ROSC may limit the problem that ‘perception of a likely adverse outcome … may well create a self-fulfilling prophecy’ [ILCOR, 3].

Unless specifically indicated (e.g. suspected cerebral bleed or stroke), routine CT brain has no current role in the management of the post arrest patient.

There is no good evidence supporting the role of CT or MRI in prognosticating post cardiac arrest [3].