Abstract
Background: The pathophysiology of sickle cell disease (SCD) is based on increased blood viscosity due to abnormal red blood cells (RBCs), which causes SCD complications, such as chronic hemolytic anemia, vaso-occlusive crisis with tissue hypoxemia, and organ dysfunction. Effective treatment of Sickle Cell Anemia is to reduce the blood concentration of Hemoglobin S (Hb S) RBCs. Exchange transfusion (ET) remains an effective but possibly underutilized therapy for the management of various acute and chronic complications of SCD such as acute chest syndrome, thromboembolic stroke, splenic and hepatic infarction, right upper quadrant syndrome, multi-organ failure syndrome, or in preparation for surgery by reducing HbS to less than 30%. RBC ET quickly replaces abnormal RBCs with normal RBCs, thus improving oxygen transport while reducing overall blood viscosity.
Methodology: To determine the effectiveness of ET in SCD in reducing the total number of admissions and total in-hospital Length of Stay (LOS) in patients, admitted with any of acute complications of SCD, we retrospectively reviewed the medical records of 38 patients between June 15, 2007 and June 15, 2008. The eligibility criteria were age above 18 years old and admission to the hospital for any SCD complication. Nineteen patients had ET with Hb A containing RBCs, generally with an average packed RBC exchange volume of 70–80 ml/kg patient’s weight. Nineteen patients were treated with conventional managements. Three patients were excluded from the ET group because of prolonged LOS due to non-SCD- related complications. Four patients in the non-Exchange group signed against medical advice on the first day of admission and were excluded from analysis.
Results: Sixteen (42.1%) patients were male and 22 (57.9%) patients were female. Their ages ranged from 19 to 67 years old, mean (SD) 30.2 (10.8). Of eligible patients, 19 (50%) patients received at least one therapeutic ET during the one year period of the study. In an independent-Samples T test analysis, the mean (SD) LOS were 7.5 (0.6) and 4.2 (0.6) days for the groups without ET and with ET respectively (95% CI = −5.2 to 1.5, p=.0011) (Figure 1). In this small studied group, this resulted average 3.3 days shorter in-hospital stay in ET group, could have saved 62 in-hospital days in the group who received conventional treatments. This number could have been easily much greater, since our hospital’s electronically stored data revealed that during year 2007, there had been 278 SCD admissions in all age groups. There was no mortality in the ET group, nor were any transfusion-related complications reported. In another analysis of one year follow up data, the number of admissions for the patients who never received ET ranged from 1 to 14, mean (SD) 1.7 (2.3) times in year 2007, while in patients who received at least one ET, the number of following admissions ranged from 0 to 2, mean (SD) 0.7 (1.3) times during the next year (95% CI = 0.16 to 1.7, p= .020). Hemoglobin level of patients in conventional treatment group on the day of discharge ranged from 6.5 to 10.7, mean (SD) 8.9 (1.9) and in ET group it ranged from 8.4 to 12.4, mean (SD) 10.2 (1.2) gr/dl (p= .045).
Conclusion: Patients with SCD are frequently admitted to hospital for vaso-occlusive crisis and other complications. Exchange transfusion is a reliable, safe, and effective therapeutic modality in SCD patients, in particular during a catastrophic event. ET can significantly reduce the number of hospital admissions and in-hospital stay days in these patients. In addition, patients managed with ET have a better hemoglobin level on discharge.
Figure Figure
A One-Year Hospital Based Prospective Study of Sickle Cell Disease from One Capital Area of Kuwait by HPLC