Abstract 210: Association of Emergency Medical Services Stroke Protocols with Minimizing On-Scene Time for Stroke Patients

Abstract

Background: Acute stroke patients require immediate medical attention. Therefore, American Stroke Association guidelines recommend that for suspected stroke cases, emergency medical services (EMS) personnel spend less than 15 minutes (min) on-scene at least 90% of the time. However, not all EMS providers include specific scene time limits in their stroke patient care protocols. We sought to determine whether a protocol with a specific time goal was associated with less time spent at the scene. Methods: Stroke protocols from each of the 100 EMS systems in North Carolina (NC) were collected and abstracted for scene time instructions. Suspected stroke events occurring in 2009 were analyzed using data from the NC Prehospital Medical Information System, a statewide electronic healthcare record used for evaluation of EMS patient care and system performance. Scene time was defined as the time from EMS arrival at the scene to departure with the patient. Quantile regression was used to estimate how the 90th percentile of the scene time distribution varied by the presence of protocol instructions limiting scene time. Models adjusted for system annual patient volume and metropolitan status. Results: In 2009, NC EMS systems varied in their stroke protocols: 23 had no instructions regarding scene time; 73 had general instructions to minimize scene time; and 4 had a specific limit for scene time (i.e. 10 or 15 min). Among 9,723 eligible suspected stroke events, mean scene time was 15.9 min (standard deviation 6.9 min) and median scene time was 15.0 min (interquartile range 11.0-19.5 min). We observed significantly lower 90th percentile scene times in EMS systems with specific time limit instructions (22.0 min) compared to systems without any instructions on scene time (24.6 min). There was no significant difference between 90th percentile scene times in EMS systems with general instructions compared to systems without instructions (25.0 versus 24.6 min). In adjusted quantile regression models, the estimated reduction in the 90th percentile scene time, comparing specific to no instructions, was 2.2 min (95% confidence interval 1.3, 3.1 min). The adjusted difference in 90th percentile scene time between general and absent instructions was not statistically different (0.7 min (95% confidence interval -0.1, 1.4 min)). Conclusion: Specific scene time limits were associated with EMS crews spending less time at the scene while general instructions were not. These findings suggest that EMS stroke protocols that include specific scene time limits are more likely to reduce on-scene times than those with no or only general instructions.