Hemodilution therapy using automated erythrocytapheresis in central retinal vein occlusion: results of a multicenter randomized controlled study
Graefe's Archive for Clinical and Experimental Ophthalmology [Albrecht Von Graefes Archiv Fur Klinische Und Experimentelle Ophthalmologie]. 2011;249((4):):505-12.
BACKGROUND Central retinal vein occlusion (CRVO) leads to poor visual outcome in most eyes. Abnormal hemorheology was suspected to play a major role in its pathogenesis. CRVO treatment is still a matter of debate but several studies have pointed out the efficacy of isovolumic hemodilution. The aim of this study was to assess the feasibility and efficacy of hemodilution using automated erythrocytapheresis in recent-onset CRVO. METHODS In this prospective randomized controlled multicenter study, 61 consecutive CRVO patients were enrolled when they met the following criteria: CRVO lasting for 3 weeks or less, visual acuity ranging from 20/200 to 20/32, age between 18 and 85 years, no diabetes, no uncontrolled systemic hypertension, no antiplatelet or anticoagulant therapy, hematocrit higher than 38%, and signed informed consent. Patients were randomly assigned to the hemodilution group (n = 31) or to the control group (n = 30). Hemodilution therapy consisted of one session of erythrocytapheresis on outpatient basis, followed by additional session(s) for 6 weeks if needed. Target hematocrit was 35%. Follow-up was 12 months. RESULTS No statistical differences in age, associated risk factors, or CRVO characteristics were observed at baseline between both groups. Mean visual acuity was equivalent to 20/80 in the hemodilution group and to 20/63 in the control group (non-significant difference). In the treated group, mean number of hemodilution sessions was 3.3 (range, 1 to 6), and no major side-effects occurred. At the 12-month follow-up visit, 64.5% of the hemodilution group had visual acuity of 20/40 or better compared to 40% of the control group (p = .048). Visual change was a gain of 1.7 ETDRS line in the hemodilution group versus a loss of 2.3 lines in the control group (p = .007). There was less conversion into an ischemic form in the hemodilution group (11%) than in the control group (50%, p = .004). Mean final retinal thickness was 289 Î¼m in the hemodilution group versus 401 Î¼m in the control group (p = .068). CONCLUSIONS This multicenter controlled randomized study demonstrated that automated erythrocytapheresis is a safe and effective tool for performing hemodilution and confirmed that hemodilution therapy can improve the final prognosis of CRVO when applied in the early phase of the disease.
Partial exchange transfusion to prevent neurodevelopmental disability in infants with polycythemia
Cochrane Database of Systematic Reviews. 2010;((1):):CD005089.
BACKGROUND Hyperviscosity of blood results in increased resistance to blood flow and decreased oxygen delivery. In the neonate, hyperviscosity can cause abnormalities of central nervous system function, hypoglycemia, decreased renal function, cardiorespiratory distress, and coagulation disorders. Hyperviscosity has been reported to be associated with long-term motor and cognitive neurodevelopmental disorders. Blood viscosity exponentially increases when an infant has polycythemia (hematocrit ≥ 65%). Partial exchange transfusion (PET) is traditionally used as the method to lower the hematocrit and treat hyperviscosity. OBJECTIVES To evaluate the effect of PET on mortality and neurodevelopmental outcome in infants with neonatal polycythemia. SEARCH STRATEGY Electronic databases searched included: The Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library), MEDLINE (1966 to October 2009), EMBASE (1980 to October 2009) and CINAHL (1982 to October 2009). SELECTION CRITERIA Randomized controlled clinical trials or quasi-randomized trials comparing partial exchange transfusion to control (non-treatment) in infants with neonatal polycythemia DATA COLLECTION AND ANALYSIS Data collection and analysis was performed according to the standards of the Cochrane Neonatal Review Group. MAIN RESULTS One study (Kumar 2004) reported no demonstrable effect on the risk of neonatal mortality (RR 5.23, 95% CI 0.66, 41.26).Four studies reported on neurodevelopmental assessment at 18 months or older. The completeness of follow-up differed widely between the studies. Overall, no difference was seen in developmental delay when all trials are analysed based on available cases (typical RR 1.45, 95% CI 0.83 to 2.54) and when only the randomized controlled trials are analysed (typical RR 1.35, 95% CI 0.68 to 2.69). A best case/worst case analysis of developmental delay is consistent with large benefit or harm from PET.Two studies reported on necrotizing enterocolitis (Van der Elst 1980; Black 1985). An increase in the risk of NEC was noted in infants receiving PET (typical RR 11.18, 95% CI 1.49, 83.64; typical RD 0.14, 95% CI 0.05, 0.22). No differences in short-term complications including hypoglycemia (two studies) and thrombocytopenia (one study) were noted. AUTHORS' CONCLUSIONS There are no proven clinically significant short or long-term benefits of PET in polycythemic newborn infants who are clinically well or who have minor symptoms related to hyperviscosity. PET may lead to an increase in the risk of NEC. The data regarding developmental follow-up is extremely imprecise due to the large number of surviving infants who were not assessed and, therefore, the true risks and benefits of PET are unclear. PARTIAL EXCHANGE TRANSFUSION TO PREVENT NEURODEVELOPMENTAL DISABILITY IN INFANTS WITH POLYCYTHEMIA Polycythemia is a condition in which there are too many red blood cells in the blood circulation. Polycythemia may occur with many different conditions. Some of the babies affected by polycythemia include those born after 42 weeks (post-term), small for gestational age (SGA )/intrauterine growth restriction (IUGR ), identical twins who share the same placenta and develop twin to twin transfusion, infants of diabetic mothers, and those with chromosomal abnormalities. Mild polycythemia may not cause problems. However, too many red blood cells can make the blood viscous', making it harder to circulate through the vessels and to the organs and cause complications.The accepted treatment of polycythemia is partial exchange transfusion (PET). PET involves slowly removing some of the blood volume and replacing the withdrawn blood with fluids to help dilute the red blood cell concentration.Treatment of polycythemia with PET is controversial. It may be associated with earlier improvement of symptoms.This review of trials found that there is no evidence of long-term benefit from PET in polycythemic infants, but the estimates of these effects are extremely imprecise due to the large number of surviving infants who were not a
Exchange transfusion as an adjunct therapy in severe Plasmodium falciparum malaria: a meta-analysis
Clinical Infectious Diseases. 2002;34((9):):1192-8.
The efficacy of exchange transfusion as an adjunct treatment for severe falciparum malaria is controversial. No sufficiently powered, randomized, controlled study has been reported. We analyzed 8 studies that compared survival rates associated with adjunct exchange transfusion with those associated with antimalarial chemotherapy alone. Exchange transfusion was not associated with a higher survival rate than was antimalarial chemotherapy alone (odds ratio (OR), 1.2; 95% confidence interval (CI), 0.7-2.1). However, patients who received transfusions had higher levels of parasitemia and more-severe malaria. Sensitivity analysis found that survival rates were higher among patients with partial immunity to malaria (OR, 0.5; 95% CI, 0.2-1.2) than they were among patients with no immunity (OR, 2.1; 95% CI, 0.9-4.8; P=.007). Exchange transfusion does not appear to increase the survival rate; however, there were significant problems with the comparability of treatment groups in the studies reviewed, and a randomized controlled trial is necessary to determine whether exchange transfusion is beneficial.