Page 2396 - Williams Hematology ( PDFDrive )

2366 Part XIII: Transfusion Medicine Chapter 138: Blood Procurement and Red Cell Transfusion 2367

whether the donor is under the care of a physician or has a history of The amount of blood withdrawn must be within prescribed limits so as
cardiovascular or lung disease, seizures, present or recent pregnancy, to maintain the proper ratio with the anticoagulant; otherwise, the blood
recent donation of blood or plasma, recent major illness or surgery, cells may be damaged and/or anticoagulation may be unsatisfactory.
unexplained weight loss, unusual bleeding, or is taking medication(s). An untoward reaction occurs after approximately 2 to 5 percent of
Some medications may make the donor unsuitable because of the con- blood donations, but, fortunately, most of the reactions are not serious.
dition requiring the medication, whereas other medications may be Donors who have reactions are more likely to be younger, unmarried,
potentially harmful to the recipient. Questions designed to protect the have a higher predonation heart rate and lower diastolic blood pressure,
safety of the recipient include those related to the donor’s general health, lower weight, female, and first-time or infrequent donors. Donors who
history of receipt of growth hormone, and occurrence of or exposure to experience a reaction are less likely to donate in the future.
patients with hepatitis or other liver disease, or a previous diagnosis of The most common reactions to blood donation are weakness, cool
HIV or AIDS (or symptoms of AIDS), Chagas disease, or babesiosis. A skin, and diaphoresis. More extensive, but still moderate, reactions are
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history also is obtained regarding the injection of drugs; receipt of coag- dizziness, pallor, hypertension, and bradycardia. Bradycardia usually
9
ulation factor concentrates; blood transfusion; tattoos; acupuncture; is considered a sign of a vasovagal reaction rather than hypotensive or
body piercing; receipt of an organ or tissue transplant; recent travel to cardiovascular shock, where tachycardia would be expected. In a more
areas endemic for malaria; recent immunizations; ingestion of medi- severe form, a vasovagal reaction may progress to loss of consciousness,
cations (especially aspirin); presence of a major illness or surgery; and convulsions, and involuntary passage of urine or stool. Other reactions
previous notice of a positive test for a transmissible disease. In addition, include nausea and vomiting; hyperventilation, sometimes leading to
several questions are related to AIDS risk behavior, including whether twitching or muscle spasms; hematoma at the venipuncture site; con-
the potential donor has had sex with anyone with AIDS, given or vulsions; and serious cardiac difficulties. Such serious reactions are rare.
received money or drugs for sex, (for males) had sex with another male, Injury of the brachial nerve and resulting pain and/or paresthesia may
or (for females) had sex with a male who has had sex with another male. occur as a result of needle puncture of the nerve or compression from
The physical examination includes determination of the tempera- a hematoma.
ture, pulse, blood pressure, weight, and blood hemoglobin (Hgb) con- Donors are advised to drink extra fluids to replace lost blood vol-
centration. The donor’s general appearance is assessed for any signs of ume and to avoid strenuous exercise for the remainder of the day of
illness or the influence of drugs or alcohol. The skin at the venipuncture donation. The latter advice is given to prevent fainting and to minimize
site is examined for signs of intravenous drug abuse, and local lesions the possibility of hematoma development at the venipuncture site. Some
that would make disinfecting the skin difficult and thus lead to contam- donors are subject to lightheadedness or even fainting if they change
ination of the blood unit during venipuncture. position quickly. Therefore, donors are advised not to return to work
for the remainder of the day if they have an occupation where fainting
would be hazardous to themselves or others.
COLLECTION OF WHOLE BLOOD
BLOOD CONTAINERS SPECIAL BLOOD DONATIONS
Blood must be collected into single-use, sterile, FDA-licensed contain- AUTOLOGOUS DONOR BLOOD
ers. The containers are made of plasticized material that is biocompatible
with blood cells and allows diffusion of gases so as to provide optimal Autologous blood for transfusion can be obtained by preoperative
cell preservation. These blood containers are combinations of bags and donation, acute normovolemic hemodilution, intraoperative salvage,
integral tubing that allow separation of the whole blood into its compo- and postoperative salvage, but only preoperative donation is discussed
nents in a closed system, thus minimizing the chance of bacterial con- here. Most commonly, this situation occurs with elective surgery. Autol-
tamination while making storage of the components for days or weeks ogous blood accounts for a very low level (<1 percent) of the United
possible. Plasticizers from the bags accumulate in red cell components States’ blood supply. 1
during storage and can be found in tissues of multitransfused patients If patient candidates for autologous blood donation meet the usual
but also in healthy nontransfused individuals. Although no evidence FDA criteria for blood donation, their blood can be used for other
indicates that transfusion of this material causes clinical problems, con- patients if the original autologous donor has no need for the blood.
tainers without plasticizers are now used in some countries. However, this practice is not allowed by AABB standards and is usually
not relevant because most patients do not meet the FDA donation cri-
teria. If the autologous donor does not meet the FDA criteria for blood
VENIPUNCTURE AND BLOOD COLLECTION donation, the blood must be specially labeled, segregated during stor-
The blood should be drawn from an area free of skin lesions and the age, and discarded if it is not used by that specific patient. Thus, the
phlebotomy site should be decontaminated. The site is scrubbed with autologous blood donation should be collected only for procedures with
a soap solution, followed by the application of tincture of iodine or a substantial likelihood that the blood will be used. Without this type of
iodophor complex solution. The venipuncture is done with a needle that planning, a very high rate of wastage of autologous blood is observed,
should be used only once in order to prevent contamination. The blood estimated at 59 percent in 2011. Thus, the cost of autologous blood is
1
must flow freely and be mixed with anticoagulant frequently as the high.
blood fills the container to prevent the development of small clots. The No age or weight restrictions exist for autologous donation. Preg-
actual time for collection of 450 to 500 mL usually is approximately 7 nant women can donate, but this practice is not recommended routinely
minutes and almost always is less than 10 minutes. During blood dona- because these patients rarely require transfusion. The autologous donor’s
tion, cardiac output falls slightly but heart rate changes little. A slight Hgb may be lower (11 g/dL) than that required for routine donors
decrease in systolic pressure results with a rise in peripheral resistance (12.5 g/dL), although usually only 2 to 4 units of blood can be obtained
and diastolic blood pressure. before the Hgb falls below 11 g/dL. Autologous blood donors can be
Usually 500 mL is collected. The blood is mixed with 63 to 70 mL given erythropoietin and iron to increase the number of units of blood
of anticoagulant composed of citrate, phosphate, and dextrose (CPD). they can donate, 10,11 although this strategy has not been shown to reduce

Kaushansky_chapter 138_p2365-2380.indd 2367 9/18/15 11:12 AM