POSTOPERATIVE BLOOD COLLECTION
Postoperative blood collection denotes the recovery of blood from
surgical drains followed by reinfusion, with or without processing.[82]
In some programs, postoperative shed blood is collected into sterile canisters and
reinfused, without processing, through a microaggregate filter. Recovered blood
is dilute, is partially hemolyzed and defibrinated, and may contain high concentrations
of cytokines. For these reasons, most programs set an upper limit on the volume
(e.g., 1400 mL) of unprocessed blood that can be reinfused. If transfusion of blood
has not begun within 6 hours of initiating the collection, the blood must be discarded.
Clinical Studies
The evolution of cardiac surgery has been accompanied by broad
experience in postoperative conservation of blood. Postoperative autologous blood
transfusion is practiced
TABLE 48-7 -- Practical considerations for intraoperative cell recovery, storage, and reinfusion
|
1. If not transfused immediately, units collected from a sterile
operating field and processed with a device for intraoperative blood collection that
washes with 0.9% saline, USP, shall be stored under one of the following conditions
prior to initiation of transfusion: |
|
At room temperature for up to 4 hours after
terminating collection; |
|
At 1–6° C for up to 24 hours, provided
that storage at 1–6° C is begun within 4 hours of ending the collection. |
|
2. Transfusion of blood collected intraoperatively by other means
shall begin within 6 hours of initiating the collection |
|
3. Each unit collected intraoperatively shall be labeled with
the patient's first name, last name, and hospital identification number; the date
and time of initiation of collection and of expiration; and the statement "For Autologous
Use Only." |
|
4. If stored in the blood bank, the unit shall be handled like
any other autologous unit. |
|
5. The transfusion of shed blood collected under postoperative
or posttraumatic conditions shall begin within 6 hours of initiating the collection. |
widely but not uniformly. Prospective and controlled trials have disagreed over
the efficacy of postoperative blood recovery in cardiac surgery patients; at least
three such studies have demonstrated lack of efficacy,[83]
[84]
[85]
while
at
least two studies have shown benefit.[86]
[87]
The disparity of results in these studies may be explained, in part, by differences
in transfusion practices. Modification of physician transfusion practices may have
been an uncredited intervention in these blood conservation studies.
In the postoperative orthopedic surgical setting, a number of
reports have similarly described the successful recovery and reinfusion of washed
[88]
and unwashed[89]
wound drainage blood from patients undergoing arthroplasty. The volume of reinfused
drainage blood has been reported to be as much as 3000 mL, and averages more than
1100 mL in patients undergoing cementless knee replacement.[89]
Because the RBC content of the fluid collected is low (hematocrit levels of 20%)
the volume of RBCs reinfused is often small.[90]
A prospective, randomized study of postoperative salvage and reinfusion in patients
undergoing total knee or hip replacement found no differences in perioperative Hb
levels or allogeneic blood transfusions between patients who did or did not have
joint drainage devices.[91]
The safety of reinfused unwashed orthopedic wound drainage has
been controversial. Theoretical concerns have been expressed regarding infusion
of potentially harmful materials in recovered blood, including free HB, RBC stroma,
marrow fat, toxic irritants, tissue or methacrylate debris, fibrin degradation products,
activated coagulation factors, and complement. Although two small studies have reported
complications,[92]
[93]
several larger studies have reported no serious adverse effects when the drainage
was passed through a standard 40-µ blood filter.[88]
[89]
[94]
The potential for decreasing exposure to allogeneic blood among
orthopedic patients undergoing postoperative blood collection, whether washed or
unwashed, is greatest for cementless bilateral total knee replacement, revision hip
or knee replacement, and long-segment spinal fusion. As in the case of intraoperative
recovery, blood loss must be sufficient to warrant the additional cost of processing
technology.[95]
As in selection of patients who
can benefit from PAD and ANH, prospective identification of patients who can benefit
from intra- and postoperative autologous blood recovery is possible if patients'
preoperative Hb level, anticipated surgical blood losses, and the perioperative "transfusion
trigger" are taken into account.
