Elektronisk udgave - Sundhedsstyrelsen

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sin; tranexamic acid; erythropoietin; hemodilution; autotransfusion;
cell salvage; device; or blood transfusion; autologous. An extensive
EMBASE search was done as well. All the titles and abstracts were
examined for studies evaluating the efficacy of the technologies for
minimizing perioperative blood use. The manufacturers of the drugs
were asked to identify any articles or reports on this subject. The references
of all relevant randomized trials, reports, review articles,
and previous meta-analyses (40, 41) were searched for other potentially
useful trials.
Only randomized trials in which the technologies were compared
with a concurrent control, and which described the proportion of
patients receiving at least one unit of allogeneic red blood cells were
included. (Studies on autotransfusion/CS in cardiac surgery were limited
to the evaluation of autotransfusion/CS initiated after coming
off cardiopulmonary bypass.) Studies were included irrespective of
whether they were full publications, abstracts or letters to the editor;
used placebo or open-label controls; or were published in English
or non-English journals. Because they have been shown to lead
to biased estimates of treatment effect (42, 43), articles that were
described as randomized, but in which clinicians could have been
aware of which treatment the patient would receive (e.g. allocation
by chart number, birth date, etc.) were excluded. Duplicate publications,
studies of children, non-elective surgery, and trials in which
patients were randomized postoperatively were excluded.
Data from the studies were independently abstracted onto study
data forms by two individuals. Disagreements were resolved by consensus.
Except for the meta-analysis of ANH, no attempt was made
to conceal the identity of the author or the medium of publication.
The primary outcome measure was the proportion of patients receiving
at least one unit of allogeneic packed red blood cells. A range
of other relevant data were abstracted 13 . The methodological quality
of the studies was reported using the Jadad scale (44). The Jadad
scale contains questions about three items: the process of randomization,
double blinding, and the description of withdrawals. Tests
for heterogeneity were performed for each meta-analysis, and if positive,
the studies that appeared to be the major contributors to the
13 Other data abstracted from the studies were the the dose of medication used for pharmeceutical agents; the volume of blood
withdrawn for ANH; the type of surgery (primary or re-operation), peri-operative myocardial infarction, re-operation because of
bleeding and pre-operative use of aspirin for cardiac surgery; the route of administration (intravenous or subcutaneous) and the
total dose (low (1800 units/kg)) of erythropoietin; the intra and post-operative transfusion thresholds
reported (hemoglobin >100 g/l, 80-100 g/l or