1.
Pre-operative autologous donation for minimising perioperative allogeneic blood transfusion
Henry DA, Carless PA, Moxey AJ, O'Connell D, Forgie MA, Wells PS, Fergusson D
Cochrane Database of Systematic Reviews. 2001;((4):):CD003602.
Abstract
BACKGROUND Public concerns regarding the safety of transfused blood have prompted re-consideration of the indications for the transfusion of allogeneic red cells (blood from an unrelated donor), and a range of techniques designed to minimise transfusion requirements. OBJECTIVES To examine the evidence for the efficacy of pre-operative autologous blood donation (PAD) in reducing the need for peri-operative allogeneic red blood cell (RBC) transfusion. SEARCH STRATEGY Articles were identified by: computer searches of OVID MEDLINE, EMBASE, and Current Contents and web sites of international health technology assessment agencies . References in the identified trials were checked and authors contacted to identify additional studies. The searches were updated in January 2004. SELECTION CRITERIA Randomised controlled trials with a concurrent control group in which adult patients, scheduled for non-urgent surgery, were randomised to PAD, or to a control group who did not receive the intervention. DATA COLLECTION AND ANALYSIS Trial quality was assessed using criteria proposed by Schulz et al (1995) and Jadad et al (1996). The principal outcomes were: the number of patients exposed to allogeneic red blood cells, and the amount of blood transfused. Other clinical outcomes are detailed in the review. MAIN RESULTS Overall PAD reduced the risk of receiving an allogeneic blood transfusion by a relative 64% (RR=0.36: 95%CI:0.25,0.51). The absolute reduction in risk of allogeneic transfusion was 43.8% (RD=-0.438: 95%CI: -0.607,-0.268). In contrast the results show that the risk of receiving any blood transfusion (allogeneic and/or autologous) is actually increased by pre-operative autologous blood donation (RR=1.33: 95%CI: 1.10,1.61). Trials were unblinded and allocation concealment was not described in 87.5% of the trials. AUTHORS' CONCLUSIONS Although the trials of PAD showed a reduction in the need for allogeneic blood the methodological quality of the trials was poor and the overall transfusion rates (allogeneic and/or autologous) in these trials were high, and were increased by recruitment into the PAD arms of the trials. This raises questions about the true benefit of PAD. In the absence of large, high quality trials using clinical endpoints, it is not possible to say whether the benefits of PAD outweigh the harms. PLAIN LANGUAGE SUMMARY Not certain that people are better off giving their own blood before surgery in case they need transfusion, when there is a safe blood bank. Although in developed countries the safety of blood supplies is high, there is still concern about contracting illness from transfusion. People often give their own blood before surgery for use if transfusion is needed (autologous donation). However, the review of trials found that it is not certain that people benefit. While pre-operative donation may reduce the chances of needing someone else's blood, it increases the chances of transfusion overall. It may be that donation causes some anaemia (low red blood cells), or surgeons are more likely to transfuse if autologous blood is available. Over-transfusion has risks, especially for older people.
2.
A meta-analysis of the effectiveness of cell salvage to minimize perioperative allogeneic blood transfusion in cardiac and orthopedic surgery. International Study of Perioperative Transfusion (ISPOT) Investigators
Huet C, Salmi LR, Fergusson D, Koopman-van-Gemert AW, Rubens F, Laupacis A
Anesthesia and Analgesia. 1999;89((4):):861-9.
Abstract
Concern about risks of allogeneic transfusion has led to an interest in methods for decreasing perioperative transfusion. To determine whether cell salvage reduces patient exposure to allogeneic blood, we performed meta-analyses of randomized trials, evaluating the effectiveness and safety of cell salvage in cardiac or orthopedic elective surgery. The primary outcome was the proportion of patients who received at least one perioperative allogeneic red cell transfusion. Twenty-seven studies were included in the meta-analyses. Cell salvage devices that do not wash salvaged blood were marginally effective in cardiac surgery patients when used postoperatively (relative risk (RR) = 0.85, 95% confidence interval (CI) = 0.79-0.92). Devices that wash or do not wash salvaged blood considerably decreased the proportion of orthopedic surgery patients who received allogeneic transfusion (RR = 0.39, 95% CI = 0.30-0.51 and RR = 0.35, 95% CI 0.26-0.46, respectively). No studies of cell savers that wash salvaged blood during cardiac surgery were included. Cell salvage did not appear to increase the frequency of adverse events. We conclude that cell salvage in orthopedic surgery decreases the risk of patients' exposure to allogeneic blood transfusion perioperatively. Postoperative cell salvage in cardiac surgery, with devices that do not wash the salvaged blood, is only marginally effective. IMPLICATIONS This meta-analysis of all published randomized trials provides the best current estimate of the effectiveness of cell salvage and is useful in guiding clinical practice. We conclude that cell salvage in orthopedic surgery decreases the proportion of patients requiring allogeneic blood transfusion perioperatively, but postoperative cell salvage is only marginally effective in cardiac surgery.
3.
Preoperative autologous donation decreases allogeneic transfusion but increases exposure to all red blood cell transfusion: results of a meta-analysis. International Study of Perioperative Transfusion (ISPOT) Investigators
Forgie MA, Wells PS, Laupacis A, Fergusson D
Archives of Internal Medicine. 1998;158((6):):610-616.
Abstract
BACKGROUND Concern about risks associated with allogeneic red blood cell transfusion has led to interest in methods of decreasing patient exposure to perioperative transfusion. OBJECTIVE To perform a meta-analysis to determine the degree to which predonation of autologous blood reduces patients' exposure to allogeneic blood and all transfusions of red blood cells (allogeneic or autologous). METHODS We searched MEDLINE, EMBASE, bibliographies, annual reports, press releases, newsletters from organizations with interests in the blood system, and personal files for randomized studies and concurrent control cohort studies in which the control groups were patients excluded for nonmedical reasons. RESULTS Patients who predonated autologous blood were less likely to receive allogeneic blood in the 6 randomized studies (n = 933) (odds ratio [OR], 0.17; 95% confidence interval [CI], 0.08-0.32) and in the 9 cohort studies (n = 2351) (OR, 0.19; 95% CI, 0.14-0.26). However, autologous donors were more likely to undergo transfusion with allogeneic and/or autologous blood (for randomized studies: OR, 3.03; 95% CI, 1.70-5.39 and for cohort studies: OR, 12.32; 95% CI, 5.90-25.40). Studies that reported use of transfusion protocols found less benefit with preoperative autologous donation, although the difference was not statistically significant. CONCLUSIONS Preoperative autologous donation of blood decreases exposure to allogeneic blood but increases exposure to any transfusion (allogeneic and/or autologous). There is a direct relationship between the transfusion rate in the control group and the benefit derived from preoperative autologous donation. This suggests that other methods of decreasing blood transfusion, such as surgical technique and transfusion protocols, may be as important as preoperative autologous donation of blood.