Thirst perception in dehydrated sickle cell disease patients in steady state.

Liberal fluid intake is one of the key management strategies in sickle cell anaemia [SCA] patients in steady state, but less work has been done on the desire of patients to drink water. Using the Visual Analogue Scale we studied thirst perception [TP] in 20 euhydrated SCA patients and 28 control [HbA] subjects, as well as during dehydration in 13 SCA patients and 9 HbA subjects. Serum and urine samples were collected and analyzed for Na, K ions, creatinine concentrations and haematocrit and specific gravity of urine were determined. During euhydration, TP was significantly [P<0.05] higher in male SCA patients compared to the HbA subjects. In females, TP in SCA patient was not statistically significant compared with HbA subjects. After 13 hours of dehydration, TP was significantly [P<0.05] reduced in female. While dehydration increased TP in HbA subjects, it reduced TP in SCA patients. Fluid intakes after dehydration in SCA patients were not significantly different from the control HbA subjects in both male and female. It can be concluded that female SCA patients do not have normal response to dehydration with regards to TP after a period of dehydration. Since dehydration stimulates the release of vasoactive hormones like vasopressin, this may explain why female patients are less prone to crisis than their male counterparts.