Using serial haemorheological parameters to assess clinical status in sickle cell anaemia patients in vaso-occlussive crisis

In a prospective study using standard methods, haemorheological parameters were assessed in 10 sickle cell anaemia patients in pain crises. Patients were investigated for possible changes in determinants of rheology in the course of painful episodes: blood samples were taken for plasma fibrinogen concentration (PFC); plasma viscosity (PV); haematocrit (Hct), whole blood viscosity (WBV) and the erythrocyte sedimentation rate (ESR) using standard methods. Samples were collected on presentation to the emergency unit and daily for 4 consecutive days. Whole blood viscosity and plasma fibrinogen concentration were significantly higher at onset of crises when compared with baseline values (p<0.01 and p<0.0001), respectively. Plasma fibrinogen and blood viscosity peaked within 24 h of onset of crisis and started declining 48-72 h later. These parameters approached baseline values by the 4th day of painful crisis. There was no significant change in the haematocrit and the erythrocyte sedimentation rate during the period of painful crisis despite change in whole blood viscosity and fibrinogen. In conclusion, this study showed elevated haemorheological parameters in sickle cell anaemia patients in VOC, it also demonstrated an acute rise in these parameters at onset of crisis and a return to almost baseline levels within 96 h of onset of painful episodes.