Lower Emergency Severity Index Assignment Results in Faster Time to First Analgesia in Patients with Sickle Cell Disease
Authors: Abu Haimed Abdulaziz , Patel Drupad , Clopton Octavia , Baer Maria R. , Stryckman Benoit , Wilkerson Richard Gentry , Law Jennie 
Published: December 2024

Introduction: Pain is the leading cause of Emergency Department (ED) visits for individuals with sickle cell disease (SCD). The National Heart, Lung, and Blood Institute recommends assigning an Emergency Severity Index (ESI) of 2 to SCD patients presenting to an ED with vaso-occlusive crisis (VOC) and administering the first dose of analgesia within 30 minutes from triage or 60 minutes from registration. The American Society of Hematology guidelines (2020) recommend reassessment of pain and opioids readministered every 30-60 minutes, as needed. Earlier assessment of VOC in the ED may result in quicker door-to-dose time for first analgesia in patients with SCD. Our study's objective is to evaluate the difference in time to first analgesia for patients with SCD assigned ESI 2 compared to those assigned ESI 3.
Methodology: We retrospectively examined the impact of ESI designation on time to first analgesia (TTFA) in patients aged 22 years and older presenting to the ED with a VOC between April 1, 2023 and September 30, 2023. 125 visits were identified, and 66 were included in the analysis. Visits for VOCs complicated by other diagnoses where an assignment of ESI 2 was warranted regardless of the presence of VOC were excluded. Visits for other acute sickle cell disease diagnoses, including acute chest syndrome, were excluded from the study. The primary outcome was TTFA, and the secondary outcome was the time to second analgesic administration (TTSA). Demographic data, pain score at triage, ESI assignment, and disposition were collected. TTFA and TTSA were compared between ESI groups using an independent t-test. A time-to-event analysis utilizing a Cox regression model evaluated the occurrence and TTFA based on age, gender, sickle cell genotype, pain level at presentation, and ESI. A linear regression model was used to analyze TTSA.
Results: The study population was 60.6% female, with a median age of 31 years. Genotype distribution included HbSS 65.2%, HbSC 12.1%, HbS-β° thalassemia 7.6%, and HbS-β+ thalassemia 15.2%. The median pain score at triage was 9/10. 34.8% of patients with SCD were assigned an ESI of 2, while 65.2% were assigned an ESI of 3. Median TTFA was 65 minutes for ESI 2 and 178 minutes for ESI 3 (P &lt; 0.001). Median TTSA was 72 minutes for ESI 2 and 78 minutes for ESI 3 (P = 0.485). Four patients assigned ESI 3 left without receiving analgesia after a median of 349 minutes. Cox regression analysis showed ESI as a significant factor for TTFA (HR 5.731, P &lt; 0.001). The linear regression model for TTSA failed to reach significance (P = 0.073). The admission rate was 39.1% for ESI 2 and 41.8% for ESI 3 (P = 0.521).
Conclusion Assignment of ESI 2 significantly impacts TTFA in patients with VOC. System-based intervention to ensure assignment of ESI 2 can improve adherence to evidence-based guidelines regarding prompt delivery of care to patients with SCD presenting with VOC.