RESUMO
The aim of this study was to evaluate the clinical, biological and genetic factors that could be associated with the use and dose of morphine during hospitalization for vaso-occlussive crisis (VOC) in adults with sickle cell disease. Ninety-nine hospitalizations for acute VOC (58 sickle cell disease patients aged 18 to 60 years, one to six hospitalizations each) were recorded; we investigated the associations between qualitative and quantitative opioid requirements and several biological, clinical, epidemiological and genetic parameters. Visual analog pain scale (VAS) was the only independent predictor of the qualitative need for morphine (mean value of 8.5 vs. 6.1 for the 77 hospitalizations that required morphine). A higher total administered morphine dose, which relates mainly to the overall crisis severity, was associated with a lower hemoglobin (Hb) level at entry. The mean daily morphine dose, which is more influenced by the individual sensitivity to morphine, was not influenced by the studied genetic parameters [sickle cell disease type, α-thalassemia (α-thal) status, UGT2B7 and ABCB1 genotypes] but a very slight negative association was found with the total bilirubin (BIL) level at entry. Our study demonstrated that physicians are often reluctant to prescribe morphine in sickle cell disease as a VAS of 6 corresponds to the usual threshold of administration in other instances. Total Hb at entry was also associated for the first time with higher total morphine consumption and could be used in a predictive VOC severity score. These results have to be confirmed and completed on larger cohorts.