Matt Morgan and Matt Wise, Consultants in Intensive Care at the University Hospital of Wales, discuss the risks of blind assumptions when thinking about a patient’s prognosis.
Prior to the publication of high-quality studies examining the syndrome of out of hospital cardiac arrest (OOHCA), this was a condition associated with almost certain death. A decade later survival rates are as high as 50% for those arriving in ED with a cardiac output (1) and most survivors have a good neurological outcome. Many of these patients will even return to work. This paradigm shift has occurred despite a paucity of new therapeutic interventions and increasing evidence that cooling offers little in the way of cognitive protection. Why then are there thousands of people walking around today, many back at work, when we were taught at medical school that they were a hopeless cause? Part of the reason is due to the increasing use of the most powerful weapon we have to treat the critically ill - time.
Nihilism around cardiac arrest survivors in the past led to evidenced-based treatments being withheld, including antibiotics, and early withdrawal of treatment. Thus the high mortality associated with cardiac arrest continued; a self-fulfilling prophecy. Only when formal prognostication guidelines, with expanded timescales, were introduced through applied research did we allow time to reveal any potential for recovery. This became even more important where therapeutic cooling was used; the reduced rate of drug metabolism leading to an additional impact on neurological recovery. There are now moves to further increase prognostication timescale in this cohort as most survivors with a good neurological outcome are not apparent until at least six days following a cardiac arrest.
In parallel with the lifting of cardiac arrest nihilism there is a new epidemic of the critically ill with devastating brain injury. This diverse condition also has a very unpredictable outcome, and time is needed for accurate prognostication. However, whilst we now offer these patients time, there is significant variation in practice related to treating reversible pathology. The development of hydrocephalus can often be predicted from initial patterns of brain injury and, without intervention, time alone will inevitably lead to death. Admission for prognostication should not be confused with admission without intervention, otherwise we will again be descending down the path of therapeutic nihilism and self-fulfilling prophecy.
Matt Morgan is an Honorary Senior Research Fellow at Cardiff University, Consultant in Intensive Care Medicine and Research and Development lead for critical care at University Hospital of Wales, and an editor of BMJ OnExamination. He is on twitter: @Matrix_Mania
Matt Wise is a Consultant in Intensive Care Medicine and Research and Development lead for Specialist Services at University Hospital of Wales.
Disclosures/conflicts: none. This work is original.
(1) Targeted Temperature Management at 33°C versus 36°C after Cardiac Arrest. https://www.nejm.org/doi/full/10.1056/NEJMoa1310519