A 72-year-old man is evaluated on postoperative day 1 following an elective total hip arth… — USMLE Step 2 CK

A $72$ -year-old man is evaluated on postoperative day $1$ following an elective total hip arthroplasty due to severe osteoarthritis. Prior to surgery, his hemoglobin was $11.2 \text{ g/dL}$ . Postoperatively, his hemoglobin dropped to $6.8 \text{ g/dL}$ , and a transfusion of $2$ units of packed red blood cells was ordered. One hour into the transfusion of the second unit, he reports severe shortness of breath and a new-onset dry cough. His medical history is significant for hypertension, type $2$ diabetes mellitus, and coronary artery disease.

Vital signs are:
- Temperature: $37.8^\circ\text{C}$ ( $100.0^\circ\text{F}$ )
- Blood pressure: $175/95 \text{ mmHg}$
- Heart rate: $112/\text{min}$
- Respiratory rate: $28/\text{min}$
- SpO $_2$ : $88\%$ on room air

Physical examination reveals elevated jugular venous pressure to $9 \text{ cm H}_2\text{O}$ . Cardiac auscultation reveals a regular tachycardia with a new $S_3$ gallop. Pulmonary examination reveals bibasilar crackles extending midway up the lung fields. There is no rash or stridor.

Laboratory studies obtained one hour prior to the transfusion:

Test	Result
Hemoglobin	$6.8 \text{ g/dL}$
Hematocrit	$21\%$
Leukocyte count	$8,400/\text{mm}^3$
Platelet count	$210,000/\text{mm}^3$
Sodium	$138 \text{ mEq/L}$
Potassium	$4.2 \text{ mEq/L}$
Blood urea nitrogen	$22 \text{ mg/dL}$
Creatinine	$1.2 \text{ mg/dL}$

Arterial blood gas (room air, during acute event):
- pH: $7.48$
- pCO $_2$ : $30 \text{ mmHg}$
- pO $_2$ : $55 \text{ mmHg}$

Which of the following is the most appropriate next step in management?

A
Discontinue the transfusion and administer intravenous epinephrine
B
Pause the transfusion, administer intravenous acetaminophen and diphenhydramine, and resume at a slower rate
C
Discontinue the transfusion, obtain blood cultures, and administer broad-spectrum intravenous antibiotics
Discontinue the transfusion and administer intravenous furosemideAnswer
E
Discontinue the transfusion and administer inhaled albuterol

Answer

The correct answer is to discontinue the transfusion and administer intravenous furosemide.

This patient's acute respiratory distress, hypertension, elevated jugular venous pressure,

S_3

gallop, and bibasilar crackles during a blood transfusion are classic for Transfusion-Associated Circulatory Overload (TACO). TACO is a form of cardiogenic pulmonary edema caused by the rapid infusion of blood products, particularly in older patients or those with underlying cardiac dysfunction. The immediate and most appropriate management is to stop the transfusion, provide respiratory support (supplemental oxygen), and administer an intravenous loop diuretic such as furosemide to rapidly reduce intravascular volume and alleviate the pulmonary edema.

Step-by-Step Solution

Analyze the patient's acute symptoms and vital signs during the blood transfusion.

The patient developed acute respiratory distress, severe hypoxia, significant hypertension, tachycardia, jugular venous distension (JVD), and an

S_3

gallop.

To identify the dominant pathophysiological process causing the acute deterioration.

Differentiate between the life-threatening transfusion reactions.

The presence of hypertension, JVD, and an

S_3

gallop in a patient with a history of coronary artery disease strongly indicates fluid overload leading to cardiogenic pulmonary edema (Transfusion-Associated Circulatory Overload, or TACO). It is distinguished from Transfusion-Related Acute Lung Injury (TRALI) and anaphylaxis, which typically present with hypotension.

Different acute transfusion reactions require distinctly different immediate management strategies.

Determine the most appropriate immediate management for TACO.

The first step is to immediately stop the transfusion to prevent further volume loading, followed by medical diuresis (e.g., intravenous furosemide) and respiratory support.

To rapidly decrease intravascular volume and alleviate the cardiopulmonary strain.

Key Concept

Transfusion-associated circulatory overload (TACO) presents with signs of volume overload (hypertension, JVD,

S_3

gallop, pulmonary edema) and is managed by immediately stopping the transfusion and administering intravenous diuretics.

Question

Answer

Step-by-Step Solution

Key Concept

Common Mistakes

Topics

More questions from this topic