PHILADELPHIA – Presumed consent for emergency thrombolysis is ethical and practical, according to the results of a population-based survey.
In an online survey of 1,100 adults aged 50 years or older, 76.9% said they would want intravenous tissue plasminogen activator for stroke. Of those surveyed, 76.0% also said they would want cardiopulmonary resuscitation for cardiac arrest. If they were unable to give informed consent in either situation, the desire for emergency thrombolysis remained essentially unchanged at 78.1%, while even more (83.6%) respondents said they would want CPR, Dr. Winston Chiong reported at the annual meeting of the American Academy of Neurology. The findings also appear in the April 23 issue of JAMA (2014;311:1689-91).
"The presumption is that ‘reasonable people’ in the middle of [an acute ischemic stroke] cascade would want thrombolytic treatment," Dr. Chiong told the platform science session blitz audience. "But this presumption has been controversial because thrombolysis has no short-term mortality benefit, unlike CPR."
In 2011, the AAN endorsed emergency thrombolysis under presumption of consent; in 2013, the American Heart Association and the American Stroke Association followed suit.
Dr. Chiong, whose interest lies in decision making and how it is affected by aging and neurodegenerative disease, said the findings provide empirical data that this presumption is justified.
He and his colleagues at the University of California, San Francisco, Memory and Aging Center randomly assigned survey participants to read one of two hypothetical scenarios. In the first, they saw themselves being brought to a hospital after having a severe acute ischemic stroke. In the second, they saw themselves have an out-of-hospital cardiac arrest that was treated by paramedics.
The stroke group was given a graphical depiction of the potential risks and benefits of treatment with thrombolysis, while the cardiac arrest group was told of the potential outcomes after paramedic-initiated CPR.
Each group was then asked whether they would want the respective treatment for their imagined scenario.
In the stroke group, 419 of 545 participants (76.9%) wanted thrombolysis, while 422 of 555 respondents (76.0%) wanted CPR for sudden cardiac arrest. Female sex, being divorced, and having less education were associated with refusing thrombolysis; poorer physical health, previous stroke, and possession of a health care advance directive was associated with refusal of CPR.
"In a clinical scenario involving an incapacitated patient where the treatment preferences are unknown and no surrogate decision maker can be found within the treatment window, we found equally strong ethical grounds for presuming thrombolysis of stroke as for presumed consent of CPR in cardiac arrest," Dr. Chiong said.
However, he underscored that despite there being a "pragmatic ethical and legal" basis for presumed consent, it is important to remember there are still a quarter of older adults who would not want the treatment if unable to consent.
"I spend a lot of time thinking about these things," he said, "The presumption of consent should not be taken to fully replace informed consent," particularly if there is some existing evidence of the patient’s wishes or if there is some question about the effectiveness of the intervention.
This study was supported in part by the American Brain Foundation Clinical Research Training Fellowship Program and grants from the National Science Foundation, the National Institute on Aging, and the National Center for Advancing Translational Sciences.
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