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Precautions and Adverse Reactions During Blood Transfusion


Ravindra Sarode

, MD, The University of Texas Southwestern Medical Center

Reviewed/Revised Feb 2022 | Modified Sep 2022

Transfusions Overview of Blood Transfusion A blood transfusion is the transfer of blood or a blood component from one healthy person (a donor) to a sick person (a recipient). Transfusions are given to increase the blood's ability to... read more Overview of Blood Transfusion are given to increase the blood's ability to carry oxygen, restore the amount of blood in the body (blood volume), and correct clotting problems. Transfusions are usually safe, but sometimes people have adverse reactions.

To minimize the chance of an adverse reaction during a transfusion, health care practitioners take several precautions. Before starting the transfusion, usually a few hours or even a few days beforehand, the person is cross-matched with the donor blood (not done for transfusions of plasma or platelets).

After double-checking labels on the bags of blood that are about to be given to ensure the units are intended for that recipient, the health care practitioner gives the blood to the recipient slowly, generally over 1 to 4 hours for each unit of blood. Because most adverse reactions occur during the first 15 minutes of the transfusion, the recipient is closely observed at first. After that, a nurse checks on the recipient periodically and must stop the transfusion if an adverse reaction occurs.

Most transfusions are safe and successful. However, mild reactions occur occasionally, and, rarely, severe and even fatal reactions may occur.

The most common reactions, which occur in 1 to 2% of transfusions, are

  • Fever

  • Allergic reactions

The most serious reactions are

  • Fluid overload

  • Lung injury

  • Destruction of red blood cells due to a mismatch between the donor's and recipient's blood type

Rare reactions include

  • Graft-versus-host disease Graft-versus-host disease (whereby transfused cells attack the cells of the person receiving a transfusion)

  • Infections

  • Complications of massive transfusion (poor blood clotting, low body temperature, and low calcium and potassium levels)


Fever may be caused by a reaction to the transfused white blood cells or to chemicals (cytokines) released by the transfused white blood cells. For this reason, most hospitals in the United States remove white blood cells from the transfused blood after it is collected.

In addition to an increase in temperature, the person has chills and sometimes headache or back pain. Sometimes the person also has symptoms of an allergic reaction such as itching Itching Itching can be very uncomfortable. It is one of the most common reasons people see doctors who specialize in skin disorders (dermatologists). Itching makes people want to scratch. Scratching... read more or a rash.

Usually, acetaminophen to reduce fever is the only treatment needed. People who have had a fever and need another transfusion may be given acetaminophen before the next transfusion.

Allergic reactions

If an allergic reaction occurs, the transfusion is stopped and the person is given an antihistamine. More serious allergic reactions may be treated with hydrocortisone or even with epinephrine.

Treatments are available that allow transfusions to be given to people who previously had allergic reactions to them. People who have repeated, severe allergic reactions to donated blood may have to be given washed red blood cells. Washing the red blood cells removes components of the donor blood that may cause allergic reactions. Because white blood cells White blood cells People are sometimes given transfusions of whole blood during severe bleeding (for example after an injury or pregnancy complications), but usually they are given only the blood component they... read more White blood cells and platelets Platelets People are sometimes given transfusions of whole blood during severe bleeding (for example after an injury or pregnancy complications), but usually they are given only the blood component they... read more Platelets are filtered out of donated blood before it is stored (a process called leukocyte reduction), allergic reactions are less common now.

Fluid overload

Transfusion recipients can receive more fluid than their body can easily handle. Too much fluid may cause swelling throughout the body or difficulty breathing. This complication is the most common cause of transfusion-related death. Recipients who have heart disease are most vulnerable, so their transfusions are given more slowly and they are monitored closely. People who receive too much fluid are given a drug to help the body remove fluid (a diuretic).

Lung injury

Another very rare reaction, called transfusion-related acute lung injury (TRALI), is caused by antibodies in the donor's plasma. This reaction may cause serious breathing difficulties. This complication is the second most common cause of transfusion-related death. It occurs in 1 in 5,000 to 1 in 10,000 transfusions, but many cases are mild and so may not be diagnosed. Most people with mild to moderate lung injuries are given oxygen and other treatments that aim to support breathing until the lungs heal. Using plasma donated by men reduces the risk of having this reaction.

Destruction of red blood cells

Despite careful typing and cross-matching of blood, mismatches due to subtle differences between donor and recipient blood (and, very rarely, errors) can still occur. When such a mismatch occurs, the recipient's body destroys the transfused red blood cells (a hemolytic reaction) shortly after the transfusion.

Usually, this reaction starts as general discomfort or anxiety during or immediately after the transfusion. Sometimes breathing difficulty, chest pressure, flushing, and severe back pain develop. Sometimes the person has cold, clammy skin and low blood pressure Low Blood Pressure Low blood pressure is blood pressure low enough to cause symptoms such as dizziness and fainting. Very low blood pressure can cause damage to organs, a process called shock. Various drugs and... read more (shock). Very rarely, the person may die.

As soon as doctors suspect a hemolytic reaction, they stop the transfusion. Doctors give treatment to support the person's breathing and blood pressure. Doctors do blood and urine tests to confirm that red blood cells are being destroyed.

Sometimes a hemolytic reaction is delayed, occurring within the month after a transfusion. Usually, such a reaction is mild and may only be noticed when blood tests are done to monitor the person's recovery from the disorder that necessitated the transfusion. These reactions occur due to the presence of an uncommon blood group antigen in the donor blood that is not routinely tested for.

Graft-versus-host disease

Graft-versus-host disease is an unusual complication that affects primarily people whose immune system is impaired by drugs or disease. In this disease, donated white blood cells (the graft) attack the recipient's (host's) tissues. The symptoms include fever, rash, low blood pressure Low Blood Pressure Low blood pressure is blood pressure low enough to cause symptoms such as dizziness and fainting. Very low blood pressure can cause damage to organs, a process called shock. Various drugs and... read more , fewer blood cells than normal (low blood counts), tissue destruction, and shock Shock Shock is a life-threatening condition in which blood flow to the organs is low, decreasing delivery of oxygen and thus causing organ damage and sometimes death. Blood pressure is usually low... read more . These reactions can be fatal. However, graft-versus-host disease can be eliminated by giving people with a weakened immune system red blood cells and platelets that have been treated with radiation.


Despite careful testing and storage of blood products, infectious organisms are sometimes transmitted during a transfusion. Testing of blood and careful evaluation of blood donors keep transmission of infectious organisms low. However, sometimes testing does not detect organisms in blood from a donor who was very recently infected or infected by an organism for which there is no test.

Complications of massive transfusion

Massive transfusion is transfusing a volume of blood equal to the person's total blood volume (about 10 units in an average adult) in a period of 24 hours or less. Such transfusion is sometimes necessary after a severe injury or during certain surgical procedures. The main complications of massive transfusion are poor blood clotting (coagulopathy) and a low body temperature (hypothermia Hypothermia Hypothermia (dangerously low body temperature) is often regarded as a cold injury, because it can be caused or made worse by exposure to cold surroundings. Being in an environment that is too... read more ).

Because blood is refrigerated while in storage, transfusion of many units of blood may result in a low body temperature. To prevent a low body temperature due to massive transfusion, doctors use a special device that gently warms the blood as it passes through the intravenous tubing.

Drugs Mentioned In This Article

Generic Name Select Brand Names
7T Gummy ES, Acephen, Aceta, Actamin, Adult Pain Relief, Anacin Aspirin Free, Aphen, Apra, Children's Acetaminophen, Children's Pain & Fever , Children's Pain Relief, Comtrex Sore Throat Relief, ED-APAP, ElixSure Fever/Pain, Feverall, Genapap, Genebs, Goody's Back & Body Pain, Infantaire, Infants' Acetaminophen, LIQUID PAIN RELIEF, Little Fevers, Little Remedies Infant Fever + Pain Reliever, Mapap, Mapap Arthritis Pain, Mapap Infants, Mapap Junior, M-PAP, Nortemp, Ofirmev, Pain & Fever , Pain and Fever , PAIN RELIEF , PAIN RELIEF Extra Strength, Panadol, PediaCare Children's Fever Reducer/Pain Reliever, PediaCare Children's Smooth Metls Fever Reducer/Pain Reliever, PediaCare Infant's Fever Reducer/Pain Reliever, Pediaphen, PHARBETOL, Plus PHARMA, Q-Pap, Q-Pap Extra Strength, Silapap, Triaminic Fever Reducer and Pain Reliever, Triaminic Infant Fever Reducer and Pain Reliever, Tylenol, Tylenol 8 Hour, Tylenol 8 Hour Arthritis Pain, Tylenol 8 Hour Muscle Aches & Pain, Tylenol Arthritis Pain, Tylenol Children's, Tylenol Children's Pain+Fever, Tylenol CrushableTablet, Tylenol Extra Strength, Tylenol Infants', Tylenol Infants Pain + Fever, Tylenol Junior Strength, Tylenol Pain + Fever, Tylenol Regular Strength, Tylenol Sore Throat, XS No Aspirin, XS Pain Reliever
A-Hydrocort, Ala-Cort, Ala-Scalp, Alkindi, Anucort-HC, Anumed-HC, Anusol HC, Aquaphor Children's Itch Relief, Aquaphor Itch Relief, Balneol for Her, Caldecort , Cetacort, Colocort , Cortaid, Cortaid Advanced, Cortaid Intensive Therapy, Cortaid Sensitive Skin, CortAlo, Cortef, Cortenema, Corticaine, Corticool, Cortifoam, Cortizone-10, Cortizone-10 Cooling Relief, Cortizone-10 External Itch Relief, Cortizone-10 Intensive Healing, Cortizone-10 Plus, Cortizone-10 Quick Shot, Cortizone-5 , Dermarest Dricort, Dermarest Eczema, Dermarest Itch Relief, Encort, First - Hydrocortisone, Gly-Cort , GRx HiCort, Hemmorex-HC, Hemorrhoidal-HC, Hemril , Hycort, Hydro Skin, Hydrocortisone in Absorbase, Hydrocortone, Hydroskin , Hydroxym, Hytone, Instacort, Lacticare HC, Locoid, Locoid Lipocream, MiCort-HC , Monistat Complete Care Instant Itch Relief Cream, Neosporin Eczema, NuCort , Nutracort, NuZon, Pandel, Penecort, Preparation H Hydrocortisone, Proctocort, Proctocream-HC, Procto-Kit, Procto-Med HC , Procto-Pak, Proctosert HC , Proctosol-HC, Proctozone-HC, Rectacort HC, Rectasol-HC, Rederm, Sarnol-HC, Scalacort, Scalpicin Anti-Itch, Solu-Cortef, Texacort, Tucks HC, Vagisil Anti-Itch, Walgreens Intensive Healing, Westcort
Adrenaclick, Adrenalin, Auvi-Q, Epifrin, EpiPen, Epipen Jr , Primatene Mist, SYMJEPI, Twinject
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