Patient Safety Tip of the Week
September 23, 2014
Stroke Thrombolysis: Need to Focus on Imaging-to-Needle Time
Patients with acute
ischemic stroke who are candidates for intravenous thrombolytic therapy benefit
most when thrombolytic therapy can be accomplished in a more timely fashion. We’ve
done a number of columns on reducing door-to-needle (DTN) times for
thrombolysis in acute stroke patients (see our Patient Safety Tips of the Week
for November 6, 2012 “Using
LEAN to Improve Stroke Care” and March 18, 2014 “Systems
Approach Improving Stroke Care”).
Many organizations
have achieved success in reducing the door-to-imaging (DTI) times. But a recent
study from Michigan (Sauser
2014) shows that we may need to focus more on the imaging-to-needle
(ITN) times. Sauser and colleagues assessed
thrombolytic therapy at 30 Michigan hospitals and found that 68.4% of patients
with acute ischemic stroke achieved DTI times within the guideline target of 25
minutes. Yet only 28.7% achieved DTN times within the guideline target of 60
minutes.
They found that neither annual stroke volume nor primary stroke center designation were significant
predictors of shorter DTN time. And patient-level factors (including stroke
severity among others) accounted for only about 15% of the variation in DTN
times between hospitals. Once they adjusted data for patient-level factors, DTI
times accounted for only 10% of the variation between hospitals whereas 65%
of the variation was attributable to differences in the ITN (imaging-to-needle) times. Thus, greater
focus is needed on improving processes that take place on completion of imaging
studies.
Many hospitals have focused their improvement efforts on
shortening the door-to-imaging (DTI) time since it has been a key component of
the Get
With The Guidelines®-Stroke program. Sauser and
colleagues point out that many of the personnel and processes involved in the
DTI and ITN intervals are different. Processes after imaging include image
interpretation, decision making, ordering and preparing tPA, laboratory testing, discussion and informed
consent with the patient and family, and administering the tPA.
This requires coordination amongst several different physicians and communication
amongst numerous healthcare personnel and other individuals.
One interesting
point of discussion in the Sauser study is the observation
that decisions take longer when the physician has more time available. They
note prior studies have demonstrated patients with shorter onset-to-arrival
(OTA) times often have longer door-to-needle (DTN) times. In our March 18, 2014
Patient Safety Tip of the Week “Systems
Approach Improving Stroke Care” we noted a study that mentioned times
to treatment are often paradoxically increased in patients having in-hospital
strokes (Meretoja 2012).
One of the key opportunities is getting those other
processes underway before or while the patient having his/her imaging studies
done. In our March 18, 2014 Patient
Safety Tip of the Week “Systems
Approach Improving Stroke Care” we discussed several studies that had demonstrated
substantial improvements in door-to-needle times. One done in the US (Binning
2014) cut its door-to-needle times by over 50% and even had several cases
with door-to-needle times under 20 minutes. The other, done in Finland,
achieved a median door-to-needle time of 20 minutes (Meretoja 2012).
In both, door-to-imaging times were reduced considerably by having the patient
taken directly by EMS personnel to the CT suite rather than to the emergency
department. However, a host of other processes were set in place as soon as the
EMS personnel notified the hospitals they had a likely stroke patient.
Expedited registration allowed for ordering the imaging studies and the blood
work. Bloods were drawn for laboratory studies as soon as the patient arrived
at the CT suite. In addition, the pharmacy is alerted so that the tPA can be prepared for administration.
Lab studies, a bottleneck in many hospitals, were expedited by using
point-of-care (POC) testing for the only two critical studies: blood glucose
levels and INR’s. A physician, adept at stroke diagnosis but not necessarily a
neurologist, evaluates the patient at the CT suite and administers the tPA right in the CT suite if the patient
meets criteria and the CT scan and lab results do not show any
contraindication.
Another key is that the process of obtaining an accurate
history (often from family) begins as soon as the EMS notification comes in. The
Finnish program had one additional advantage often not available in the US: an
integrated electronic health record.
Another key factor is immediate interpretation of the
imaging study. If a radiologist is not available for interpretation (either
on-site or remotely) the “stroke” physician interprets it. The Finnish study
also emphasizes the need to keep imaging simple. They just do standard
non-contrast CT and reserve advanced imaging like perfusion imaging for unclear
cases only.
Meretoja and colleagues concluded
“the key to success in reducing the delays is to do only the basics while the
patient has arrived, and to do as much as possible before, during transport.”
Reducing the overall door-to-needle times gives the stroke
patient better odds of good functional outcome. Moreover, the reduced times
also increase the percentage of stroke patients that are eligible for
thrombolytic therapy. In the Binning study the percentage of patients receiving
tPA increased to 18% from
their historical rate of 5%.
We suggest that you
read our prior columns, listed below, that have good links to many of the good
performance improvement studies done on thrombolytic therapy and links to
resources from the American Heart Association/American Stroke
Association's Target: Stroke Initiative.
Some of our previous columns on improving stroke care:
November 6, 2012 “Using
LEAN to Improve Stroke Care”
March 18, 2014 “Systems
Approach Improving Stroke Care”
References:
Sauser K, Levine DA, Nickles AV, Reeve MJ. Hospital Variation in
Thrombolysis Times Among Patients With Acute Ischemic StrokeThe
Contributions of Door-to-Imaging Time and Imaging-to-Needle Time. JAMA Neurol. 2014;
71(9): 1155-1161
http://archneur.jamanetwork.com/article.aspx?articleid=1886777
Meretoja A, Strbian
D, Mustanoja S, et al. Reducing in-hospital delay to
20 minutes in stroke thrombolysis. Neurology 2012; 79: 306–313
http://www.neurology.org/content/79/4/306.abstract
American Heart Association. Get With The Guidelines®-Stroke
program.
Binning MJ, Sanfillippo G, Rosen W
et al. The Neurological Emergency Room and Prehospital
Stroke Alert: The Whole Is Greater Than the Sum of Its Parts. Neurosurgery
2014; 74(3): 281–285
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