Evaluation of a Quality Improvement Intervention for Anesthetic Management of Acute Ischemic Stroke Patients Undergoing Endovascular Therapy

Thesis (Master's)--University of Washington, 2016-06

BACKGROUNDS: For acute ischemic stroke (AIS) cases receiving endovascular therapy (EVT), the use of general anesthesia (GA), physiological perturbations, and delays in the institution of EVT adversely impact the outcomes. In 2012, a quality improvement (QI) intervention utilizing PDSA (Plan-Do-Study-Act) model was implemented at Harborview Medical Center (HMC) aiming at minimizing delays for EVT, encouraging the use of monitored anesthesia care (as opposed to the routine use of general anesthesia) and avoiding physiologic perturbations under anesthesia, to improve neurological outcomes of the patients. The objective of this project is to evaluate the effectiveness of the QI intervention quantitatively. METHODS: This is a retrospective pre-post interventional study. The study period was separated into pre-intervention period (Jan 2008 to May 2012), QI intervention roll-out period (Jun 2012 to Nov 2012, the first six months of implementation), and post-intervention period (Dec 2012 to Aug 15th, 2015.) Patient characteristics, choice of anesthetic technique (general anesthesia or monitored anesthesia care), arterial line placement rate, timeliness indicators, intra-procedural physiological parameters, and clinical outcomes were collected and compared between pre-intervention and post-intervention phases. Multi-level generalized estimating equation models were used to estimate the clinical impacts. RESULTS: Data from 78 patients from pre-intervention phase and 43 patients from post-intervention phase were compared. The use of general anesthesia decreased from 97.4% to 72.1% (p<0.0005). The use of arterial catheter decreased from 75.6% to 39.5% (p<0.0005). The median anesthesia-ready time decreased from 14 to 12 minutes (p=0.007). The median door-to-puncture time decreased from 111 to 82 minutes (p=0.02). The prevalence of intra-procedural relative hypotension (non-invasive SBP below the recommended 140mmHg) decreased from 100% to 90.7% (p=0.006). No significant decreases in respiratory parameters were identified (EtCO2>40 mmHg, EtCO2<30 mmHg, SpO2<92%). The subjects in post-intervention phase had lower in-hospital all-cause mortality, (adjusted OR 0.67 [0.55-0.80]; p<0.0005), higher likelihood of favorable neurologic outcome (mRS≤2, adjusted OR 1.27 [0.42-3.8]; p=0.67) and favorable discharge disposition (adjusted OR 1.57 [0.88-2.8]; p=0.13), shorter hospital stay (adjusted IRR 0.79 [0.51-1.19]; p=0.25) and ICU stay (adjusted IRR 0.61 [0.51-1.19]; p=0.25). DISCUSSION: The QI intervention utilizing interdisciplinary “PDSA” model effectively changed physician decision-making for anesthesia technique choice and was significantly associated with less delay to treatment, less relative hypotension, and better survival.