He appears well developed and of normal height and weight for his age. His is alert and oriented and cooperative. He is in moderate distress owing to anxiety and arm pain. Diaphoresis is apparent on the forehead. He is extremely tachycardic with a vigorous cardiac impulse. He has no other injuries. His exam is otherwise unremarkable.

An IV is placed in the uninjured arm. Labs are sent. The hematocrit is 35%. He is given 3 L of normal saline while waiting for cross-matched blood. The hematocrit is now 25%. Cross-matched blood is being transfused. The orthopedic surgeon has been summoned.

A UTR is minor allergic reaction associated with the transfusion of a blood product. The reaction is limited to the appearance of hives. None of the more serious allergic findings occur; i.e., there is no wheezing, hypotension and angioedema. It is caused by an antigen/antibody interaction upon exposure to donor blood product. A number of donor serum protein antigens have been implicated.

When a UTR occurs, the transfusion can be paused while the patient is evaluated. Once the more serious finding are ruled out, the transfusion can be restarted. Antihistamine can be given. Prophylactic antihistamine can be considered but is not routinely recommended.

Cutaneous manifestations such as urticaria, erythema, pruritus, and/or angioedema are almost always present. Wheezing and hypotension usually develop which can be severe. Gastrointestinal symptoms such as nausea, vomiting, and diarrhea may be present. The patient may have the feeling of impending doom. The onset is typically 5–30 min after intravenous exposure.

Anaphylaxis is a medical emergency. The transfusion should be stopped. Help should be summoned. High-flow oxygen should be administered. Adequate IV access should be obtained. If warranted, IO can be considered. Begin aggressive fluid resuscitation with NS. The patent should be monitored by continuous ECG and pulse oximetry. Blood pressure should be checked with a cuff, or if necessary, by direct palpation. Anaphylaxis is due to the release of inflammatory mediators such as histamine and cytokines from mast cells and basophils. Epinephrine slows the release of these mediators; hence, rapid administration of epinephrine is a key intervention. Intramuscular (IM) epinephrine administration is favored but IV should be considered if there are immediate life-threatening manifestations. H1 antihistamines such as diphenhydramine should be administered. H2 blockers such as cimetidine can also be given. If bronchospasm is present, inhaled beta-adrenergic agonist should be administered. A high-dose IV corticosteroid should be administered early but the benefits of corticosteroids will not manifest for several hours. The blood product should be sent back to the lab for reanalysis.

An acute hemolytic transfusion reaction is a life-threatening emergency caused intravascular hemolysis of transfused erythrocytes. The most common cause is a clerical error resulting in transfusion of mismatched blood. The patient may complain of chills, anxiety, nausea, shortness of breath, and flank pain. Patients may develop a fever, hypotension, and brown urine. The signs and symptoms usually begin within 15 min of starting the transfusion. If not recognized, life-threatening hyperkalemia can develop owing to the on-going release of potassium from the on-going hemolysis. If a patient is under anesthesia, the findings can include hypotension, urticaria, wheezing, hyperkalemia, ECG changes, blood-tinged urine, and abnormal bleeding. The hemolyzed erythrocytes release hemoglobin and other proteins into the serum. These proteins precipitate in the renal tubules where they can cause blockage and eventual renal failure. The coagulation cascade can become activated (by erythrocytin and other factors) thereby consuming platelets and clotting factors including fibrinogen. This can progress to the disseminated intravascular coagulation syndrome.