Stroke evaluation, diagnosis and treatment was briefly addressed in last issue’s “Perspective” titled “Is thrombolytic therapy for stroke the standard of care?” Recent articles highlight the need for more information for attorneys on this subject.
Liability risk greatest for doctors not using tPA for stroke
An August article by Liang and Zivin (Ann Emerg Med. 2008;52:160-164) concludes that “litigation involving stroke therapy with tPA indicates liability is predominantly associated with failure to provide tPA, rather than adverse events associated with its use.” There are several likely reasons for this, including (1) far fewer patients are eligible to receive treatment than those who get it, and (2) informed consent is likely thorough in those patients being treated, while probably non-existent in many of the cases not treated. Pharmaceutical marketing and the development of “stroke centers” have led patients, families, attorneys, and even some physicians to overestimate the value of this therapy. (Note: Of the 33 cases evaluated for this article, 21 resulted in defense verdicts.)
The results of this study indicate that hospitals and physicians should be informing patients about the reasons they are not receiving the “clot buster” whenever the drug might be considered an option, either by the medical literature or the patient and family.
What are the statistics? What’s the benefit? What’s the risk?
In general, thrombolytic therapy benefits only about 8% of patients. Given 100 eligible patients (the major criteria being that the patient receive the drug within 3 hours* http://www.ahrq.gov/clinic/epcsums/acstrokesum.htm of onset of symptoms; beyond that, the risks exceed the benefits), the outcome of 91 of those patients will not be changed. Eight of the patients are likely to benefit from the treatment. One will be harmed, and about half of those harmed will die. The treatment is not without risk. Many patients with stroke, however, seem willing to take the risk, viewing death as preferable to major disability. The point here is that ALL patients with stroke need to have a discussion with their physician about the risks and benefits of treatment.
* Click here for an abstract from NEJM, September 25, 2008, suggesting that this time limit can safely be extended to 4.5 hours.
If it’s a TIA and not a stroke, what’s the risk?
In 2007 Johnston et al. published the ABCD scoring system to help stratify the risk of stroke in patients with Transient Ischemic Attacks or TIAs (Johnston SC et al. Validation and refinement of scores to predict very early stroke risk after transient ischaemic attack. Lancet. 2007;369:283-292.) The scoring system is as follows:
Age > 60 1 point
Systolic BP > or = 140 1 point
Diastolic BP > or = 90 1 point
Unilateral weakness 2 points
Speech impairment w/o weakness 1 point
TIA duration > or = 60 minutes 2 points
TIA duration 10 – 59 minutes 1 point
Diabetes 1 point
Results show that a patient has the following likelihood of stroke given the following scores:
Score 2 day stroke prevalence 7 day prevalence 90 day prevalence
0-3 1.0% 1.2% 3.1%
4-5 4.1% 5.9% 9.8%
6+ 8.1% 12.0% 18.0%
The authors recommend admission to the hospital for all patients with a score of 3 or higher, though a score of 4 is being used by some hospitals.
Just because a patient has a high score using this system does not determine treatment, other than that all patients not allergic to aspirin and not on a blood thinner or platelet inhibitor should be given aspirin (Stroke 2008;39;1647-1652; originally published online Mar 5, 2008). Time since onset, prior medical history, medications, CT scan results, etc. all play a role in determining therapy.
Survey finds challenges to appropriate use of tPA in stroke
Finally, here’s a recent University of Michigan survey of emergency physicians that identifies some of the reasons that tPA is still not widely used in stroke treatment. Highlights include:
One thing that this survey shows is that there are still many emergency physicians who question the whole science behind this issue. Many of them have been quite successful helping juries wade through these murky waters to the benefit of defense attorneys in the growing number of cases of “failure to treat” or “loss of chance” when a patient experiencing stroke or TIA symptoms has questioned the standard of care.