The 'pit-crew' model for improving door-to-needle times in endovascular stroke therapy: a Six-Sigma project

Abstract

Background: Delays in delivering endovascular stroke therapy adversely affect outcomes. Time-sensitive treatments such as stroke interventions benefit from methodically developed protocols. Clearly defined roles in these protocols allow for parallel processing of tasks, resulting in consistent delivery of care.

Objective: To present the outcomes of a quality-improvement (QI) process directed at reducing stroke treatment times in a tertiary level academic medical center.

Methods: A Six-Sigma-based QI process was developed over a 3-month period. After an initial analysis, procedures were implemented and fine-tuned to identify and address rate-limiting steps in the endovascular care pathway. Prospectively recorded treatment times were then compared in two groups of patients who were treated 'before' (n=64) or 'after' (n=30) the QI process. Three time intervals were measured: emergency room (ER) to arrival for CT scan (ER-CT), CT scan to interventional laboratory arrival (CT-Lab), and interventional laboratory arrival to groin puncture (Lab-puncture).

Results: The ER-CT time was 40 (±29) min in the 'before' and 26 (±15) min in the 'after' group (p=0.008). The CT-Lab time was 87 (±47) min in the 'before' and 51 (±33) min in the 'after' group (p=0.0002). The Lab-puncture time was 24 (±11) min in the 'before' and 15 (±4) min in the 'after' group (p<0.0001). The overall ER-arrival to groin-puncture time was reduced from 2 h, 31 min (±51) min in the 'before' to 1 h, 33 min (±37) min in the 'after' group, (p<0.0001). The improved times were seen for both working hours and off-hours interventions.

Conclusions: A protocol-driven process can significantly improve efficiency of care in time-sensitive stroke interventions.

Keywords: Standards; Stroke.

Figure 1

An overview of the protocol is presented along a timeline from patient arrival to arterial puncture. The role of different team members is listed along the timeline. ER, emergency room; GETA, general endotracheal anesthesia, off hours treatment: stroke intervention performed before 7:00 or after 17:00 or at the weekend; ICU, intensive care unit; INR, neurointerventionalist; LCFA, left common femoral artery; LSN, last seen normal; LVO, large vessel occlusion; NIHSS, National Institutes of Health Stroke Scale; onset-ER, time from symptom onset to ER arrival; RCFA, right common femoral artery; rt-PA, recombinant tissue plasminogen activator.

Figure 2

INR: neurointerventionalist, T1: technician-1, T2: technician-2, T3: technician-3, N1: nurse-1, N2: nurse-2, A1: anesthesiologist/certified registered nurse anesthetist (CRNA)-1, A2: anesthesiologist/CRNA-2. During the patient preparation stage (A), T1 sets up the procedure trays and prepares the devices and catheters. T2 prepares the patient and helps the attending technician, who punctures the right femoral artery and typically places an 8 Fr sheath. The patient's left arm is extended out on an arm board for simultaneous access to anesthesia for placement of lines and administration of drugs. If there is no radial arterial access by the time the right femoral sheath is placed, the INR punctures the left femoral artery and places a 4 Fr sheath for invasive blood pressure monitoring. Even though it is possible to obtain arterial tracing via the 8 Fr right femoral sheath, placement of the 4 Fr sheath allows removal of the larger right femoral sheath at the end of the procedure. The patient is transferred to the intensive care unit with the 4 Fr sheath in place for pressure monitoring. The nurse takes a report, prepares the continuous flush lines, assists the anesthesiologist, and charts all times. The A-plane detector is stationed in such a way as to allow easy positioning over the groin in case fluoroscopy is required. For the interventional stage (B), T2 scrubs up and functions as the float. One anesthesiologist (A1) stays to cover the case, assisted by the nurse. This setup with stocked anesthesia cart is duplicated in an immediately adjacent second interventional biplane room. During working hours an additional technician (T3) and nurse (N2) are available. If two simultaneous emergent cases occur after hours, the technicians split and the backup nurse (N2) is called in.

Figure 3

Graphic comparison of the treatment times ‘before’ and ‘after’ implementation of the quality-improvement process.