Platelets are essential to the blood clotting process. Patients with a low platelet count risk massive bleeding after even a slight injury. The only treatment for this life-threatening condition is a transfusion of platelets from a healthy donor. The most efficient collection method---called apheresis, or plateletpheresis---uses an automated cell separator to collect a full therapeutic dose of platelets from a single donor. Since most of the donor's blood is returned him, apheresis reactions are less common than in whole blood donation, but the risk of severe reactions is higher, according to a report published by Dr. Jeffrey L. Winters in the July 2006 issue of the Journal of Clinical Apheresis.
Venipuncture Injury
Platelet donation requires the insertion of a needle---venipuncture---into one or both of the donor's arms. Venipuncture can cause bruises or clots at the insertion site. The American Red Cross advises donors to minimize these risks by leaving the post-donation bandage in place for at least five hours and avoiding strenuous activity for the rest of the day. On the other hand, although it is a common concern among donors, the danger of introducing air into the bloodstream is remote, according to Winters.
Anticoagulant Reaction
The most common apheresis risk, according to Winters, is hypocalcemia---low calcium in the blood---caused by an anticoagulant used to prevent clotting in the apparatus. This reaction is usually mild, involving just a slight tingling sensation around the lips and nose, which resolves when the procedure is over. Sometimes, however, the reaction can be severe.
Low Blood Pressure
Low blood pressure causes patients to feel lightheaded or to faint. Since the automated collection process returns the blood, minus platelets, to the donor, the risk of low blood pressure is lower than in whole blood donation. According to Winters, this side effect is uncommon in automated platelet collection.
Fatigue
Other side effects, such as feeling tired, are much like those from whole blood donation. The American Red Cross recommends drinking plenty of caffeine-free fluids and eating a well-balanced meal before donating to reduce the risk of post-donation fatigue.
Long-Term Effects
The possible long-term effects of repeated platelet donation may include bone demineralization and problems with platelet production, according to Winters, but additional research is needed. Currently, donors are permitted to donate platelets as often as every three days, up to a maximum of 24 times a year.
References
- American Red Cross: Platelet Donation
- "Transfusion": Moderate and Severe Adverse Events Associated With Apheresis Donations
- Merck Manual: Low Platelets
- American Cancer Society: Blood and Its Components
- "Journal of Clinical Apheresis"; Complications of Donor Apheresis; Jeffrey L. Winters, M.D.; July 2006
