Soru

A 74-year-old man is hospitalized for the management of melena and severe symptomatic anemia. He has a notable medical history of essential hypertension, type 2 diabetes mellitus, and stage 3 chronic kidney disease. Upon admission, his hemoglobin level is $5.8 \text{ g/dL}$, and he is prescribed three units of packed red blood cells. Approximately 30 minutes into the transfusion of the third unit, the patient reports sudden-onset shortness of breath and a dry cough.

Current vital signs include a temperature of $37.2^\circ\text{C}$ ($99.0^\circ\text{F}$), blood pressure of $178/96 \text{ mm Hg}$, heart rate of $115/\text{min}$, and respiratory rate of $26/\text{min}$. Pulse oximetry displays an oxygen saturation of $86\%$ while breathing room air.

Physical examination shows prominent jugular venous distention when the patient is seated at a 45-degree angle. Auscultation of the lungs reveals bilateral basilar crackles without any audible wheezing. Cardiac examination demonstrates a regular tachycardia with a prominent S3 gallop.

An arterial blood gas analysis on room air yields the following results:

pH: $7.28$
PaCO $_2$: $56 \text{ mm Hg}$
PaO $_2$: $52 \text{ mm Hg}$
HCO $_3^-$: $25 \text{ mEq/L}$

A portable chest radiograph displays bilateral pulmonary infiltrates, an enlarged cardiac silhouette, and widening of the vascular pedicle.

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