Jeffrey McCullough - Transfusion Medicine

Because seizures may occur following blood donation, a history of seizures has disqualified donors in the past. However, donors with a history of seizures well controlled at the time of donation have not demonstrated greater likelihood of experiencing a reaction to donation than donors who never had seizures [70]. Questions regarding seizures are not a standard part of universal donor screening, and blood banks have a variety of policies regarding deferral if a history of seizures is given.

During venipuncture, the needle may accidentally strike a nerve. Injuries causing numbness or tingling, pain, and/or loss of arm or hand strength occur in 1 in 21,000–26,700 donations [71, 72] and implies that approximately 600 injuries may occur annually in the United States. Some of the donors developed a hematoma after donation, but it could not be determined whether the nerve damage was related to the hematoma or direct injury by the needle. One‐third of the injuries resolved in less than 3 days, but 2% lasted longer than 6 months and 6% resulted in residual mild localized numbness [72].

In a detailed anatomic study of 11 patients with injury to upper extremity cutaneous nerves after routine venipuncture, Horowitz [73] observed that nerve injury appeared secondary to direct trauma via “inappropriate” needle or bolused material near the nerves and outside the target veins. However, in 3 of 13 additional patients, the venipunctures were properly performed and atraumatic. He explored the anatomic relationships of superficial veins and cutaneous nerves at three common venipuncture sites in the 14 upper extremities of seven randomly chosen cadavers. Major branches of cutaneous nerves were superficial to and overlay veins in 6 of the 14 extremities studied. In multiple instances, nerves and veins were intertwined. He concluded that anatomic relationships between upper extremity superficial veins and cutaneous nerves are so intimate that needle–nerve contact during venipuncture is common. Because venipuncture‐induced nerve injuries are rare, factors other than direct nerve contact appear necessary for the chronic pain syndrome to occur.

Arm complications such as hematoma and/or arm pain occur in about 30% of donors [74]. A hematoma occurs commonly after blood donation even though the arm is inspected, and donors are advised to apply pressure to the area. Usually these hematomas are not serious, but they cause some local discoloration of the antecubital fossa. A more serious but rare complication is the development of a large hematoma often due to arterial puncture. This can cause pressure on vessels or nerves and injury in the antecubital fossa. Reports of symptoms suggesting this type of complication should be dealt with urgently by the blood center so that the donor can receive rapid attention and drainage of the fossa if necessary to prevent more serious injury. Although rare, deep vein thrombosis of the upper extremities has been reported as a complication of whole blood donation [75, 76].

Blood may be collected as part of therapy for diseases, such as polycythemia vera or hemochromatosis. Because the procedure is being performed as a therapy, these individuals are patients, not donors. Their medical assessment then is focused on determining that the phlebotomy is safe for the patient. The patients may meet all of the criteria for whole blood donation except for the presence of the disease for which they are undergoing phlebotomy. However, as described earlier in this chapter, blood collected as therapeutic bleeding is not routinely used for transfusion, although in recent years the FDA has allowed variances so that blood from patients with benign conditions, such as hemochromatosis or secondary polycythemia, may be distributed by blood centers for patient use.

The selection of donors for plateletpheresis, leukapheresis, and plasmapheresis uses the same general criteria used for whole blood donors [1]. Because of the unique nature of apheresis, there are some additional donor requirements that are based on the unique complications that may occur from apheresis, the nature of the procedures, and the fact that because few red cells are removed, donors can undergo cytapheresis more often than whole blood donation. The amount of blood components removed from apheresis donors must be monitored. To be consistent with whole blood donation, not more than 200 mL of red cells may be removed in 8 weeks. If for some reason, such as instrument failure, it is not possible to return the red cells to the donor, then the donation is treated as if it were a whole blood donation, and the donor cannot donate again for 8 weeks. For consistency with plasma donation, not more than 1,000–1,200 mL of plasma per week may be retained. When donors undergo apheresis more often than every 8 weeks, this is referred to as “serial” donation, and cumulative records must be maintained of the details of these donations, and the records must be reviewed periodically to assure that requirements related to red blood cells and plasma are met. The laboratory testing of donors and apheresis components for nonbacterial pathogens is essentially the same as for whole blood donation. Thus, the likelihood of disease transmission from apheresis components is similar to whole blood components.

In one study of 2,069 plateletphereses in 352 donors, or an average of six procedures per donor, the following important observations were made that formed the basis of subsequent FDA regulations for the selection and monitoring of cytapheresis donors: (a) among women, platelet counts averaged 12% higher than those of males; (b) about 3% of all donors had platelet counts less than 150,000/mL before their first platelet donation; (c) the preapheresis platelet count was the best predictor of the postapheresis platelet count; (d) if donors with a preapheresis count of less than 150,000 were excluded, only 13% of donations resulted in a postapheresis count of less than 100,000; (e) the platelet count decreased about 30% immediately after apheresis; (f) the platelet count returned to normal about 4–6 days after apheresis; and (g) there was a slight rebound in platelet count above the initial count about 8–11 days after apheresis. Although the decrease in platelet count varies with the procedure used, a decrease of 20–35% generally occurs and the platelet count returns to baseline levels about 4 days after donation [77]. The platelet count decreases less than expected based on the number of platelets collected [78] because platelets are mobilized during the apheresis procedure [79].

A platelet count is not necessary before the initial donation because the decrease in platelet count following donation is not so extensive as to create a risk for the donor. At least 48 hours must elapse between platelet donations. If donors are to donate more frequently than every 4 weeks, a platelet count must be done to ensure that it is at least 150,000/μL before a subsequent donation. The platelet count can be obtained before the donation, or a count obtained after a previous donation can be used. Platelet donors should not have taken aspirin or drugs that interfere with platelet function, or must wait the specified time interval for that drug before donating (e.g., 3‐day waiting period for aspirin).

Collection of platelets, granulocytes, lymphocytes, or stem cells by cytapheresis results in very little red cell loss. Thus, red cell depletion is not considered a possible complication of any individual collection unless there is an instrument malfunction. However, because apheresis collections can occur with high frequency (e.g., 24 plateletpheresis collections in 12 months), cumulative red cell loss from test sampling can cause anemia and low ferritin stores [80].