Implementation of a Stroke Code System in Mobile, Alabama
Diagnostic and Therapeutic Yield
Background and Purpose There is now therapy of proven benefit for acute ischemic stroke. Successful interventional therapy for stroke patients requires implementation of a system that facilitates rapid triage and diagnostic evaluation.
Methods We initiated a 24-hour, 7-day-per-week stroke code system at the University of South Alabama Hospitals and prospectively collected data from the first 100 patients whose clinical presentations triggered this system.
Results Seventy-eight patients (78%) had acute ischemic stroke. Of the remaining 22, 9 had evidence of intracerebral hemorrhage. The most common nonstroke diagnosis was seizure (n=5). Forty-eight of the 87 stroke patients (55%) presented within 6 hours of stroke onset (40/78=51% of the ischemic stroke patients), and 35 of the 87 (40%) presented within 3 hours of onset (28/78=36% of the ischemic stroke patients). Thirty-one (31% of the group overall; 40% of the ischemic stroke patients) were eligible for acute therapy. Twenty-five of these eligible patients were entered into a treatment study, 4 declined participation, and 2 were treated with open-label tissue plasminogen activator.
Conclusions Implementation of a stroke code system may result in a high yield of patients with acute stroke and relatively few “stroke mimickers.” A significant proportion of all cases generated will be eligible for acute treatment under current experimental protocols or with tissue plasminogen activator, but the majority will not.
With publication of the NINDS TPA trial results in December 1995, there is now therapy of proven benefit for acute ischemic stroke.1 TPA and most experimental therapies must be administered within a few hours of stroke onset. Therefore, successful interventional therapy for stroke patients requires implementation of a system that facilitates rapid triage and diagnostic evaluation. The resulting impact on clinical practice may be significant for physicians who treat acute ischemic stroke, especially those considering implementation of such a system. Relevant questions include the following: How often will the system be activated? What will be the distribution of activations throughout a 24-hour period or given week? What percentage of patients actually will have ischemic stroke? How many patients will be eligible for acute treatment? We present our experience with the implementation of a “stroke code” system that was designed to minimize both prehospital and intrahospital delays in the evaluation and management of stroke patients.
Subjects and Methods
We initiated a 24-hour, 7-day-per-week stroke code system at the USA hospitals on June 13, 1995, and through March 8, 1996, we prospectively collected data from the first 100 patients whose clinical presentations triggered this system. USA hospitals include a 406-bed university medical center, 100-bed university-associated community hospital, and 159-bed children’s hospital; the latter was not included in the system. The system was activated by EMS personnel, nurses, or physicians who suspected acute stroke with onset of less than 24 hours. Before and during the study period, multiple training seminars were conducted for EMS personnel in the Mobile region. These seminars were specifically intended to improve stroke recognition and to minimize prehospital delays through the development of a protocol for the management of patients with presumed stroke in the field. In addition, stroke-related continuing medical education programs for primary care physicians throughout south Alabama were conducted regularly. One of three attending stroke neurologists was on call at all times.
We recorded age, sex, race, sponsorship, date and time of symptom onset and system activation, and the time to potential acute therapeutic intervention (TTPATI), defined as the time from symptom onset to either arrival at a USA hospital or stroke code activation (whichever was later). Patients for whom a precise stroke onset time could not be determined (eg, those who awakened from sleep with a focal neurological deficit) were designated as having stroke onset at the time they were last known to be symptom free. We also recorded mode of transportation to the hospital (self-transport, transport by family/friends, EMS transport, transfer from another facility, or other) and diagnosis, as determined by a stroke neurologist (ischemic stroke, intracerebral hemorrhage, or nonstroke) during the hospitalization (typically at the time of initial evaluation); nonstroke diagnoses were specified. Finally, we recorded patient disposition (enrolled into an acute ischemic stroke treatment protocol, patient/family refusal to participate in a treatment protocol, or exclusion from a treatment protocol) and, when a patient was excluded from acute treatment, the specific reason for that exclusion. All treatment decisions were made by the treating stroke neurologist.
Of the first 100 patients triggering our stroke code system, 87 (87%) were diagnosed with acute stroke by a USA Stroke Center neurologist; 78 (78%) had an ischemic stroke, and 9 (9%) had an intracerebral hemorrhage. All diagnoses, including the 13 nonstroke diagnoses (“stroke mimickers”), are listed in the Table⇓. Of the stroke patients, 50% were white, 50% were black, and 67% were male; the mean age was 63 years. Sponsorship was distributed as follows: Medicare (41%), none (22%), Medicaid (15%), Blue Cross Blue Shield of Alabama (11%), Prime Health HMO (7%), and other commercial insurance (4%).
Fig 1⇓ indicates the distribution of TTPATI for all stroke patients, and Fig 2⇓ shows the same for patients with ischemic stroke. Forty-eight of the 87 stroke patients (55%) presented within 6 hours of stroke onset (40/78=51% of the ischemic stroke patients), and 35 of the 87 (40%) presented within 3 hours of onset (28/78=36% of the ischemic stroke patients). Fig 3⇓ indicates the times of day that the stroke codes occurred, by epoch. The modes of transportation to USA hospitals for all stroke patients are shown in Fig 4⇓. Patients categorized as “other” in this figure included an outpatient scheduled for a CT scan and an incarcerated patient who was transported by correctional officers. Seven patients (78%) with intracerebral hemorrhage used the EMS system, and 2 (22%) were transported by family/friends.
Thirty-one (31% of the group overall; 40% of the ischemic stroke patients) were eligible for enrollment into a treatment protocol. We entered 25 of these eligible patients into an experimental treatment study; 4 declined participation, and 2 were treated with open-label TPA subsequent to the publication of the NINDS TPA study results.1 Of the 27 treated patients, 12 presented within 3 hours, 5 between 3 and 6 hours, and 10 between 6 and 24 hours; 7 patients were treated within 3 hours, 9 between 3 and 6 hours, and 11 between 6 and 24 hours.
Of the patients with ischemic stroke who were ineligible for participation under a treatment protocol, the most common reason for exclusion was significant spontaneous neurological improvement (16/78=21% of the ischemic stroke patients overall and 16/47=34% of the excluded patients). Other reasons for exclusion included TTPATI greater than 24 hours (7), age outside of protocol parameters (4), a preexisting neurological deficit confounding examination (3), active ethanol use (2), inability to obtain informed consent (2), and the discovery of a coexisting meningioma that consequently confounded diagnosis (2).
Our stroke code system produced an 87% yield of acute stroke. Using different methods, other groups have reported an accuracy of stroke diagnosis ranging from 72% for EMS personnel2 to 98.6% for emergency physicians.3 Libman et al4 reported a diagnostic accuracy of 81% for patients presenting to their emergency department. The importance of rapid and accurate diagnosis of stroke has been recently magnified by the advent of interventions (such as thrombolysis) that carry significant risks. Errors in diagnosis and/or the determination of time of symptom onset now have serious patient care implications.
Of the ischemic stroke patients, 36% presented to the hospital within 3 hours and 51% within 6 hours. Although our system was designed to be activated for all patients within 24 hours of symptom onset due to our participation in an ischemic stroke study with a 24-hour enrollment window, most experimental protocols have enrollment windows of less than 6 to 8 hours, and intravenous TPA currently must be administered within 3 hours of stroke onset. At this point, then, if a 6-hour window for acute intervention were to be implemented, nearly half of our ischemic stroke patients would be ineligible for treatment by virtue of TTPATI alone. Barsan et al5 and Biller et al6 reported that 59% and 53% of their patients, respectively, presented within 3 hours. The disparity with our results may be explained in part by the fact that both authors studied populations at hospitals with well-established acute stroke intervention programs; our program is novel to the region served.
Of potential significance is that only 45% of our stroke patients presented through the EMS system. Patients who initially contact 911 arrive at the emergency department nearly twice as quickly as those who contact their primary physician or have family or friends transport them.5 Further public education efforts in our community may increase the percentage of acute stroke patients using the EMS system and thus decrease TTPATI.
Of the group overall, only 25% were enrolled in an acute ischemic stroke treatment protocol, a figure similar to the therapeutic yield reported by Lyden et al.7 Just over one third of all patients excluded were so managed because of significant spontaneous neurological improvement, leaving approximately two thirds of excluded patients ineligible for acute intervention despite significant neurological deficits; of these, over a third presented more than 24 hours after symptom onset. Public and professional education has been shown to reduce the delay in presentation of stroke patients,8 and our data suggest that continued educational efforts may be necessary in our region.
Of interest to the practicing physician, more than three quarters (78%) of stroke codes occurred between 6 am and 6 pm. Although relatively convenient for the staff of a university-based stroke service, this distribution may prove disproportionately burdensome for the private practitioner who typically has outpatient care commitments during this time period. Since TPA recently has been approved by the Federal Drug Administration for stroke and other hyperacute therapies are sure to follow, the neurological community now must face the issue of implementation and determine the most efficient system for managing the acute stroke patient.
We have shown that implementation of a stroke code system may result in a high yield of patients with acute stroke and relatively few stroke mimickers. A significant proportion of all cases generated will be eligible for acute treatment, but the majority will not. In our community, further public education emphasizing stroke recognition and the use of the EMS system may be necessary to increase the percentage of stroke patients eligible for acute treatment intervention.
Selected Abbreviations and Acronyms
|EMS||=||emergency medical service|
|NINDS||=||National Institute of Neurological Disorders and Stroke|
|TPA||=||tissue plasminogen activator|
|TTPATI||=||time to potential acute therapeutic intervention|
|USA||=||University of South Alabama|
This study was supported in part by a grant from the American Heart Association, Alabama Affiliate. The authors wish to express their gratitude to the EMS personnel of Mobile County, Baldwin County, and the City of Mobile. Without their efforts and unfailing enthusiasm, our work in acute stroke treatment could not be accomplished.
- Received November 25, 1996.
- Revision received February 24, 1997.
- Accepted February 24, 1997.
- Copyright © 1997 by American Heart Association
Kothari R, Barsan W, Brott T, Broderick J, Ashbrock S. Frequency and accuracy of prehospital diagnosis of acute stroke. Stroke. 1995;26:937-941.
Kothari RU, Brott T, Broderick JP, Hamilton CA. Emergency physicians: accuracy in the diagnosis of stroke. Stroke. 1995;26:2238-2241.
Biller J, Patrick JT, Shepard A, Adams HP. Delay time between onset of ischemic stroke and hospital arrival. J Stroke Cerebrovasc Dis. 1993;3:228-230.
Lyden PD, Rapp K, Babcock T, Rothrock J. Ultra-rapid identification, triage, and enrollment of stroke patients into clinical trials. J Stroke Cerebrovasc Dis. 1994;4:106-113.
Alberts MJ, Perry A, Dawson DV, Bertels C. Effects of public and professional education on reducing the delay in presentation and referral of stroke patients. Stroke. 1992;23:352-356.