Infectious complications to transfusion may be

bacterial or viral. Bacterial infections are more common

after platelet transfusion (stored at room temperature)

and longer blood storage times. Organisms are most

commonly skin or gastrointestinal flora. Diagnosis

requires positive cultures from donor and r ecipient blood.

Donor blood is prescreened for human immunodefi ­

ciency virus (HIV), hepatitis B virus (HBV), hepatitis C

virus (HCV), cytomegalovirus ( CMV), human

T-lymphotropic virus (HTLV), West Nile virus (WNV),

and parvovirus; nevertheless, there is a small r isk of transmission of these pathogens (most commonly HCV)

despite screening.

Massive transfusions put the patient at risk for developing coagulopathy, hyperkalemia, lactic acidosis, and hypothermia. Dilutional coagulopathy or thrombocytopenia can occur

when >4 PRBCs are transfused within 1 hour or 10 units

within 12 hours, without the addition of clotting factors or

platelets. Hypocalcemia and metabolic alkalosis may o�cur

due to the effect of citrate. Volume overload from transfusiOns

is more common in the setting of underlying chronic cardiac

or kidney disease as well as plasma transfusion. Patients present with acute pulmonary edema without fever or shock.

Graft-versus-host disease is a rare complication of

transfusion seen in irnmunocompromised or familial

recipients. It is associated with a very high mortality rate.

Donor T lymphocytes attack recipient tissues. This complication is prevented by leukoreduction and irradiation.

Patients may present with fever, rash, pneumonitis, abdominal pain, vomiting, diarrhea, transaminitis, and thrombocytopenia.

The incidence of transfusion-related complications is

highlighted in Table 72- 1.

Acute

Acute hemolysis

Anaphylaxis

Sepsis

TRALI

Simple febrile reaction

Minor allergic

Hepatitis B

Hepatitis C

HIV

Delayed

Incidence

1 in 0.25-1 million

1 in 20,00D-150,000

1 in 5 million

1 in 5,000-10,000

1 in 1 00

1 in 1,000

Incidence

1 in 1 37,000

1 in 1-2 million

1 in 2-3 million

CLINICAL PRESENTATION

� History

Fevers and chills may be seen in acute febrile reactions, acute

intravascular hemolysis, anaphylaxis, sepsis due to bacterial

contamination, or TRALI. Chest pain, shortness of breath,

lightheadedness, or syncope may be seen in the same conditions. Isolated shortness of breath during transfusion is suggestive of volume overload, whereas generalized pruri�us �d

rash (in the absence of other symptoms) suggests urt1car1a.

Risk factors for developing a transfusion-related reaction

include immunocompromised recipients, those requiring

massive transfusion, a history of receiving blood transfusions, preexisting congestive heart failure, or elderly patients.

For example, recipients who are irnmunocompromised are

at increased risk for graft-versus-host disease. Patients

receiving massive transfusions are at significant risk for

hypothermia and coagulopathy. Elderly patients or patients

with congestive heart failure are at risk for pulmonary

edema, particularly when blood products are transfused too

rapidly. Also, patients who have been transfused blood products in the past are at increased risk of having preexisting

antibodies, which may cause a variety of transfusion-related

reactions. See the Introduction for classic presentations.

� Physical Examination

During transfusion, patients should be monitored closely

for adverse reactions. New vital sign abnormalities that

develop such as fever, hypotension, tachycardia, or tachypnea are all concerning for possible transfusion reaction.

Even well-appearing patients who develop fever during

transfusion should have the transfusion stopped and be

closely monitored for more serious reactions, as they may

quickly decompensate. In patients with hypotension,

tachycardia, or tachypnea, it is difficult to distinguish

ongoing hemorrhage (the underlying reason for many

transfusions) from potentially life-threatening transfusion

reactions including acute intravascular hemolysis, anaphylaxis, or sepsis. Classically, hypovolemic shock will cause

cool extremities, whereas the shock states seen in acute

intravascular hemolysis, anaphylaxis, or sepsis cause cardiovascular collapse and warm extremities. Patients receiving massive transfusions are at risk of hypothermia, whi�h

also may occur due to sepsis. Wheezing may be noted m

anaphylaxis or pulmonary edema (due to volume overload

or TRALI). Hives or rash is seen in anaphylaxis or urticaria.

Dark pink or brown urine indicate hemoglobinuria after

acute intravascular hemolysis.

DIAGNOSTIC STUDIES

� Laboratory

Laboratory studies are performed to document appropriate

response to transfusion ( eg, rise in hemoglobin) and to aid

in identifying acute intravascular hemolysis, sepsis, or

CHAPTER 72

other symptoms that develop acutely during a transfusion.

Transfusions should always be held pending these results,

and the laboratory should be notified to test samples of

both donor and recipient blood. Most hospitals have

protocols to ensure that the correct blood is transfused to

the correct patient and to manage a possible transfusion reaction.

Basic laboratory tests are generally not helpful in acute

febrile reactions, urticaria, anaphylaxis, TRALI, or volume

overload. Their utility in the ED is in identifying acute

intravascular hemolysis or sepsis. In acute hemolytic

reactions, complete blood count (CBC) may reveal

worsening anemia and schistocytes. Other laboratory

findings include a positive Coombs test, acute renal failure,

DIC, and/or elevated haptoglobin, bilirubin, and lactate

dehydrogenase levels. Hemoglobinuria may be seen on

urinalysis.

If sepsis is suspected, Gram stain and blood cultures

should be ordered. CBC may reveal leukocytosis or

leukopenia; however, sepsis cannot be ruled out definitely

in their absence.

Transfusion

During massive transfusion, dilutional thrombocytopenia or coagulopathy, metabolic acidosis, and hypocalcemia may occur.

..... Imaging

In suspected cases of TRALI or volume overload, a chest

x-ray may demonstrate acute pulmonary edema. In general,

patientswithvolumeoverloadwillhavecardiomegaly,whereas

patients with TRALI will have a normal-heart size. Bedside

ultrasound may help differentiate volume overload from

TRALI. Volume overload is associated with poor cardiac

contractility and inferior vena cava distension, whereas in

TRALI, both of those features would be normal.

MEDICAL DECISION MAKING

Different transfusion reactions present similarly; however,

it is important to differentiate which type of reaction is

occurring to appropriately direct treatment and disposition (Figure 72-1). If there is any suspicion of a transfusion

reaction, the first step is to stop the transfusion.

Sign or symptom

of a transfusion

reaction

Acute hemolytic

reaction

Stop the

transfusion

Fever only

Simple febrile

reaction

Shortness of breath

Pulmonary

edema

TRALI or

fluid

overload

Hypotension,

wheezes,

rash, pruritus

Allergic

reaction

(anaphylaxis)

Figure 72-1. Transfusion reactions diagnostic algorithm.

TRANSFUSION REACTIONS

If the patient experiences a fever with no other signs or

symptoms, a simple febrile reaction is likely. However, it

may be difficult clinically to distinguish between other