especially lightheadedness or syncope, may occur when the donor is having refreshments. Donors are advised to drink extra fluids to replace and maintain lost blood volume. The nature of the fluid is generally left to donor discretion, except that alcoholic beverages are not recommended. Alcohol is a vasodilator and may cause a shift of blood flow to the periphery, resulting in reduced cerebral blood flow and hypotension or fainting. Even after the loss of a few hundred milliliters of blood, some donors are subject to lightheadedness or even fainting if they change position quickly. Therefore, donors are also advised not to return to work for the remainder of the day in an occupation where fainting would be hazardous to themselves or others. Likewise, donors are also advised to avoid strenuous exercise for the remainder of the day [54]. This may also minimize the chance of hematoma development at the venipuncture site.
Adverse reactions
Reactions have been associated with approximately 4% of blood donations, although many either occur or are first noticed when the donor is off‐site, which complicates accurate reporting. Fortunately, most reactions are not serious [55–57]. Minimizing donor reactions begins with the selection of the site for blood collection, the staff training, the general treatment the donor receives from the staff, and the ambience of the blood collection situation. These factors are important because reactions increase when the blood collection situation is crowded, noisy, or hot, or when the donor endures a long wait. Donors who have reactions are more likely to be younger [58, 59], to be unmarried, to have a higher predonation heart rate and lower diastolic blood pressure, and to be first‐time donors or to have donated fewer times than donors who do not experience reactions [59].
Adverse reactions to whole blood donation can be categorized generally as those due to: (a) hypovolemia, (b) vasovagal effects, and (c) complications of the venipuncture (Table 4.4). The most common symptoms of reaction to blood donation are weakness, cool skin, diaphoresis, and pallor. A more extensive but still moderate reaction may involve dizziness, pallor, hypertension, hypotension, and/or bradycardia. Bradycardia is usually taken as a sign of a vasovagal reaction rather than hypotensive or cardiovascular shock, in which tachycardia would be expected. The vasovagal syndrome can have detrimental effects on blood donors and the blood supply [60, 61]. The most common cause of these symptoms is probably due to the psychological stress of the situation or to neurologic factors rather than hypovolemia caused by loss of blood volume. In the past, a common response to a donor reaction was to have the donor rebreathe into a paper bag. This is effective only if the lightheadedness is due to hyperventilation and reduced bicarbonate levels. Most reactions do not have this basis, and the paper bag may only add to the tension of the situation. This is not recommended as routine practice, but should be reserved for situations in which it seems clear that hyperventilation is a major part of the reaction. Other systemic reactions may include nausea, vomiting, and hyperventilation, sometimes leading to twitching or muscle spasms, convulsions, or serious cardiac difficulties. These kinds of serious reactions are rare. Several strategies have been used to reduce donor reactions, especially in populations of young, first‐time donors, such as 16‐to 17‐year‐old students, who are seen as important to building a future donor base [62]. Intervention strategies studied include predonation education, distraction, and additional water intake, which can reduce the rate of vasovagal reactions [63–65]. Minimizing donor reactions is very important because donors who experience adverse reactions are less likely to return [60, 66, 67].
Table 4.4 Adverse reactions to whole blood donation.
| Hypovolemia | Syncope |
| Lightheadedness | |
| Diaphoresis | |
| Nausea | |
| Vomiting | |
| Vasovagal effects | Syncope |
| Bradycardia | |
| Diaphoresis | |
| Pallor | |
| Venipuncture | Hematoma |
| Nerve injury | |
| Local infection | |
| Thrombophlebitis |
No clinically significant positive or negative effects have been proved for long‐term, even multigallon, donors of whole blood, although there has been interest in determining impact on areas such as cardiovascular health, occurrence of malignancy, and immunologic response. In recent years, taking precautionary measures to protect young donors from iron depletion has become an area of interest, because there are concerns regarding neurologic development of adolescent donors and possible sequelae if young females become pregnant [68, 69].
Severe reactions to blood donation
Although most reactions are mild, severe reactions defined as those requiring hospitalization can occur. These include seizures, myocardial infarction, tetany, and death. Popovsky [57] reviewed 4,100,000 blood donations and found very severe reactions in 0.0005%, or 1 per 198,110 allogeneic blood donations. The kinds of reaction included severe vasovagal reaction, angina, tetany, and problems related to the venipuncture site. Most reactions occurred during donation while the donor was at the donor site, although 6% occurred more than 3 days later. Reactions were more likely in first‐time donors. If this incidence is generalized to the total yearly donations of 15 million, approximately 75 such reactions may occur annually.
Seizures
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.
Nerve injuries
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
