Drepadom - a Homecare Protocol for Vaso-Occlusive Crisis for Sickle Cell Disease Patients
Authors: Pelinski Yanis , De Luna Gonzalo , Kassasseya Christian , Morabito Antonio , Ngwem Elsa , Arlet Jean-Benoit , Genty Isabelle , Honsel Vasco , Habibi Anoosha , Le Jeune Sylvain , Bartolucci Pablo 
Published: December 2023

INTRODUCTION
Vaso-occlusive crisis (VOC) is first cause of emergency room (ER) admissions and hospitalizations for sickle-cell disease (SCD) patients. Acute chest syndrome (ACS) is a complication that can occur during VOC and prolong hospitalization, and is the main cause of death in SCD patients. The PRESEV score (Bartolucci - eBioMed 2016), established by our team, allows physicians to evaluate the risk of developing ACS and is calculated upon arrival to the ER and has been validated by an international multicenter study in five different countries (PRESEV 2 - ASH 2020).
During the Covid-19 pandemic, we set up a temporary system to monitor VOC patients at home using a telephone hotline and homecare services. The success of this system led to the establishment of DREPADOM, a home-care protocol for VOC management for patients with low risk of developing ACS, or who can be discharged early from the hospital, as standard care (DREPADOM - ASH 2021). Since 2021, Drepadom has been successfully running in seven hospitals in the Parisian region.
DESCRIPTION OF SETTING
Drepadom has two inclusion modes: 1/ Patients arriving at the ER for VOC with a PRESEV score ≤ 6 and not presenting any exclusion criteria; 2/ patients that are discharged early following hospitalization for VOC and/or ACS (after at least 3 days of hospitalization for patients with PRESEV &gt; 6 upon ER arrival).
The Drepadom homecare protocol is activated by a coordinator, who coordinates delivery of PO opioids and parenteral treatments, and a home oxygen concentrator, to the patients' home within four hours. Drepadom uses an online platform and mobile app (Link4Life), where the patient's medical record is shared to the homecare nurse who will perform house calls twice a day. During each visit, the nurse enters the patient's vitals into the app, which are monitored by an on-call SCD expert physician. The online platform also hosts a secure messaging service where nurses, doctors and coordinators can communicate in real-time regarding patient status and care, as well as an automatic alert system that is triggered when vitals fall outside of a predetermined range set by SCD experts. Patient safety is further ensured with a daily calls to the patient using a decision-making algorithm supervised by SCD experts, who arbitrate according to the evolution of the situation (stopping/continuing outpatient follow-up vs. rehospitalization).
RESULTS
Over a 30-month period we had 209 inclusions for 170 patients into DREPADOM. Of these, 105 were inclusions from the ER and 104 were early discharges (ED). SCD genotype distribution was 83.2% SS, 10.5% SC, and 5.8% S-bThalassemia and female to male ratio was 128:81. In both ER and ED groups, median age was 31 [27-40], 74% of patients were under hydroxyurea treatment and median homecare follow-up duration was 3 [2-4] days. No significant differences in population characteristics were found between the ER and ED groups.
In the ER group, 96/105 patients (91.4%) were included with PRESEV ≤ 6. 9/105 (8.6%) patients were included with a PRESEV score &gt;6 only in 2021 during the Covid-19 pandemic, when the ER was saturated. In the PRESEV ≤ 6 group, 9/96 (9.4%) patients were rehospitalized: 1 for ACS (PRESEV = 4), 4 for uncontrolled VOC pain, 2 for chest pain, 2 for fever/infection unrelated to VOC. In the PRESEV &gt;6 group, 3/9 (33%) were hospitalized, one for ACS (PRESEV = 8), one for uncontrolled VOC pain and one for issues with veinous access.
In the ED group, patients were hospitalized for a median of 4.5 [3-7] days before being discharged. 27 patients (26%) were included in a post-ACS context. 48/104 (46.2%) had a PRESEV ≤6, of which only 2/48 (4.2%) were rehospitalized for uncontrolled VOC pain. Of the 56/104 (53.8%) patients included with a PRESEV &gt; 6, 8/56 (14.3%) were rehospitalized: 1 for ACS, 3 for uncontrolled VOC pain, 1 for chest pain, 1 for fever/infection unrelated to VOC, 1 for issues with veinous access, and 1 for morphine withdrawal symptoms.
For both ER and ED groups, a total of 22/209 patients (11%) required rehospitalization (Figure 1), and no deaths or ICU were reported in either group.
PERSPECTIVES
Our results confirm that Drepadom is a successful and safe tool to reduce hospital stay for SCD patients.