Plasma donation, a process known as plasmapheresis, involves collecting a donor’s blood, separating the liquid plasma component, and returning the remaining blood cells to the donor’s body. This specialized type of donation is a medical necessity, providing the raw material for therapies that treat serious conditions like immune deficiencies, hemophilia, and various autoimmune disorders. Because a machine is used to extract and return blood components, the process requires strict health guidelines to ensure the donor’s well-being. A thorough health screening, including a blood pressure check, is performed before every donation.
Specific Blood Pressure Limits for Plasma Donation
The maximum blood pressure considered safe for plasma donation is strictly regulated by federal guidelines in the United States. A donor’s systolic blood pressure, which represents the pressure in the arteries when the heart beats, must not exceed 180 millimeters of mercury (mmHg). Correspondingly, the diastolic blood pressure, which measures the pressure in the arteries between heartbeats, cannot be above 100 mmHg.
If a donor’s blood pressure reading is higher than 180/100 mmHg, they are automatically deferred from donating that day. These ceilings are paired with minimum requirements to ensure the donor’s circulatory system is stable, typically requiring the systolic reading to be at least 90 mmHg and the diastolic reading to be at least 50 mmHg.
Readings outside of this acceptable range (90–180 mmHg systolic and 50–100 mmHg diastolic) indicate that the donor’s cardiovascular system may be under too much strain. The donation center staff must follow these federal mandates precisely, meaning any reading outside the acceptable range will result in a temporary disqualification. This deferral is a direct safety measure designed to protect the donor from potential adverse reactions during the procedure.
Why Strict Blood Pressure Screening is Necessary
The rigorous blood pressure screening acts as a safeguard because the plasmapheresis process temporarily alters the body’s fluid balance. The procedure involves removing a significant volume of plasma, often between 625 to 800 milliliters, which can cause a short-term decrease in blood volume. This temporary hypovolemia, or reduced blood volume, directly impacts the donor’s blood pressure.
For a person with pre-existing or undiagnosed hypertension, the fluid shift and subsequent drop in volume can place excessive strain on the cardiovascular system. This strain increases the potential for adverse reactions, such as feeling dizzy, fainting, or experiencing a vasovagal response. The strict limits are set to exclude individuals whose bodies might not be able to compensate for the fluid loss safely.
Addressing High Blood Pressure Readings at the Center
When a donor’s blood pressure is measured above the maximum allowable limit, it leads to a temporary deferral rather than a permanent ban. This temporary rejection acknowledges that many factors can cause a blood pressure spike on a given day. Common reasons include anxiety from the donation process itself, sometimes referred to as “white coat syndrome,” recent consumption of caffeine, or high levels of stress.
In these instances, donation centers often permit the donor to wait for a short period, typically 15 to 30 minutes, to relax and have their blood pressure re-checked. If the subsequent reading falls within the acceptable range, the donor may proceed with the donation. If the reading remains too high, the center will defer the donor for the day and advise them to return once their blood pressure is consistently under control. For future appointments, donors can improve their chances of passing the screening by ensuring they are well-rested and properly hydrated, while avoiding stimulants like coffee or high-sodium foods before arriving.
Other Essential Health Screening Requirements
Beyond blood pressure, plasma donors must meet several other health criteria to ensure their safety and the quality of the plasma product.
Weight and Blood Volume
A minimum weight requirement is enforced; donors must weigh at least 110 pounds (50 kilograms). This minimum is tied to calculating the safe blood volume that can be removed during donation.
Hematocrit and Hemoglobin
A finger-prick test measures the donor’s hematocrit level (percentage of red blood cells) and total protein level. Female donors must have a hemoglobin level of at least 12.5 grams per deciliter, and male donors must have at least 13.0 grams per deciliter.
Pulse and Temperature
The donor’s pulse must be regular and fall between 50 and 100 beats per minute. Body temperature must not exceed 99.5 degrees Fahrenheit (37.5 degrees Celsius).