The Impact of Delays in Administering TPA for Ischemic Stroke Patients

Problem Description
Ischemic strokes occur when a portion of the brain loses oxygen supply in sufficient levels to support the needs of neurons (Patel & White, 2011). Studies have demonstrated the effectiveness of antiplatelet therapy both for treatment of current ischemic strokes and for prevention of future strokes ( Pinto et al., 2009). One of the keys to optimal response to an ischemic stroke is to provide the patient with a set of support therapies within a three-hour window, including IV recombinant tissue plasminogen activator (TPA) as long as no contraindications for TPA therapy are present (Biller, 2008; Patel & White, 2011).  These contraindications include but are not limited to presentation beyond 3 hours after symptom onset, signs of cranial hemorrhage, stroke or head trauma within preceding 3 months, history of seizures, surgery within 3 weeks, and blood test contraindications (platelets<100,000/ml or glucose<50mg/dl) (Patel & White, 2011). Speed is of the essence in treating ischemic stroke. Inappropriate treatment with TPA has been reported in some cases, however, so it is important to understand the impact of TPA therapy on patient outcomes (Uchino, Massaro & Hammer, 2010).

Research Approach
A large metropolitan area hospital in southern California, the Emergency Department (ED) sees between 100 and 200 cases of ischemic stroke a year. The issue is to determine in how many of these cases administration of TPA was delayed and what impact, if any, that delay had on the patient outcomes.

Purpose of Research
The purpose of the research is to determine first, if current delays in administering TPA have impacted patient outcomes, and second, to suggest types of improvements in ischemic stroke care that will provide improved patient outcomes.

Role of Researcher and Researcher Bias
The researcher will be scrutinizing hospital records for the year 2010, during which approximately 168 ischemic stroke cases came through the ED of this hospital.  The researcher’s bias is that in some cases, the administration of TPA was too delayed to have the hoped-for improvement in the patient condition. Preliminary permission to access patient records for the period of interest (i.e., Jan. 1, 2010 to Dec. 31, 2010) has been gained, pending approval of this research proposal.

Since the data to be collected is objective and numerical (i.e., time of administration of TPA, how long patient in hospital, where patient discharged to, other clinical measures), the data collection effort is subject to little direct bias. However, there is a potential for bias in the determination of which cases from hospital records will be excluded from the study.  In order to reduce this bias, specific and detailed exclusion and inclusion criteria must be defined prior to beginning the research effort.  Examples of possible exclusion issues include age of patient, comorbidities, delay between onset of symptoms and presentation of the patient at the hospital.  A specific written policy must be defined and followed throughout the data collection process.

Sampling Techniques to Be Used
The hospital records for the 168 stroke cases in the hospital will be scrutinized. This will be a sample based on specific criteria, with every case from this hospital meeting inclusion criteria being included I the study. For identified inclusion cases, specific data from the hospital records will be culled including:

• Patient demographics (gender, age, stated ethnicity)
• Ischemic stroke diagnosis (yes/no)
• Time from presentation to administration of TPA (in hours; 0 if never administered)
• Days of hospital stay of patient
• Where patient released to (home, other medical facility such as rehab, or deceased)

While this is not a convenience sample from within the specific hospital records, it is a convenience sample in that it contains only patients from one specific metropolitan hospital which is a center for neurological disease. Thus, the hospital acts as a regional center and cases from this hospital should reflect ischemic patients from this region.

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