Effectiveness Of An Analgesia Protocol For The Treatment Of Painful Vaso-Occlusive Crisis Of Sickle Cell Disease Patients In Emergency Room: A Retrospective Cohort Study
Authors: Naessens Veronique , Ward Richard , Kuo Kevin H.M. 
Published: October 2019

Background
Painful vaso-occlusive crisis (VOC) is the most frequent complication of sickle cell disease (SCD) and the main reason for interacting with the emergency room (ER). Guidelines highlight the need for rapid opiate delivery (< 30 min.) via specific analgesia protocol in order to achieve rapid pain control and reduce length of stay (LOS).

Objectives
To determine the rate of utilization of an analgesia protocol for SCD patients presenting with painful VOC to ER. Secondary objectives are to examine the relationship between protocol use, LOS, discharge from ER, time to first opiate delivery, total amount of opiates, and time to readmission.

Methods
An analgesia protocol, developed according to the BCSH guideline, was deployed in the ER of a major SCD comprehensive care center in Canada since 2009. A retrospective observational study was conducted of all SCD patients who presented to the ER with painful VOC between August 2009 and September 2012. Frequent ER visitor was defined as >3 visits/year. Factors influencing protocol use and discharge from ER were examined via Chi-squared test and multivariable logistic regression. Mann-Whitney U test and multiple regression were used to examine factors related to time to first opiate administration, LOS in ER, total quantity of opiates used, and as well as time to readmission.

Results
602 ER visits were included in the analysis, comprising of 116 patients (61 males, 55 females) with 82% HbSS or S/β0. The median number of visits in the observation period was 2 (1 to 90), with 12 patients responsible for 57% of visits. The protocol was used in only 51% of visits, frequent ER attenders were less likely to be treated by the protocol (OR 0.989 per additional visit, p=0.007). Higher pain score on presentation was significantly associated with protocol use (OR 1.194 per 1 point increment, p=0.001), which in turn reduced the time to first opiate administration (69 vs. 108 min., p<0.001). Visits treated by protocol were longer (457 min vs. 385 min. in ER, p<0.001), used more opiates (95 vs. 50 mg PO morphine equi-analgesic dose, p<0.001) and patients were less likely to be discharged home (OR 0.78, p=0.003), though it prolonged the time to next ER admission (22 vs. 15 days, p=0.008). The length of inpatient admission was not affected by prior use of the Protocol in ER.

Conclusion
In this, the largest single-center report of ER sickle cell care, the rate of protocol use was moderate and although it resulted in faster delivery of first opiate dose, time to delivery did not reach the recommended target of 30 minutes. Protocol use did not positively influence any other outcomes. The protocol was preferentially used in patients who attends the ER infrequently. Further refinement of the protocol may lead to improvements in utilization by ER staff, leading to shorter time to first analgesia administration. This in turn may result in the protocol having a greater impact on patient outcomes in ER.

Disclosures:
No relevant conflicts of interest to declare.