Packed red blood cells (PRBCs) contain erythrocytes from whole blood collection (hematocrit [Ht] 0.68 ± 0.03) and a minimal number of platelets and leukocytes. All blood products in Canada undergo leukoreduction; this has been shown to be associated with a lower risk of human leukocyte antigen (HLA) alloimmunization, transfusion-related cytomegalovirus (CMV) transmission, and febrile nonhemolytic transfusion reactions. PRBCs may be stored at 1 to 6 degrees Celsius for up to 42 days. Transfusion of 1 unit of PRBCs usually results in a hemoglobin (Hb) increase of ~10 g/L.
Special PRBC products: Table 9.7-1.
1. In hemodynamically stable hospitalized patients, adopt a conservative transfusion strategy. Consider PRBC transfusion in patients with Hb ≤70 g/L.
2. In the perioperative period, studies suggest that an Hb threshold ≤75 g/L is adequate for cardiac surgery and ≤80 g/L for orthopedic surgery.
3. In patients with acute coronary syndrome, there is insufficient evidence to recommend an Hb threshold. Consider maintaining Hb >80 g/L. A transfusion threshold of 80 g/L should also be considered in patients with preexisting cardiovascular disease.
4. In case of clinical manifestations of anemia (eg, chest pain, orthostatic hypotension, tachycardia, congestive heart failure), transfuse as required based on symptoms.
In stable adult patients transfuse slowly (50 mL/h) for the first 15 minutes of a PRBC transfusion (for pediatric patients, transfuse slowly [1 mg/kg/h, up to 50 mL/h] for the first 15 minutes). Each PRBC unit is typically infused over 2 hours, with a maximum duration of 4 hours. Slowing the transfusion rate, as well as using pretransfusion diuretics, should be considered for patients at risk of transfusion-associated circulatory overload. The patient’s vital signs should be checked prior to starting each unit, 15 minutes after starting, at the end of the transfusion, and during any transfusion reaction. Outside of emergency situations, always transfuse 1 PRBC unit at a time and measure Hb afterwards to determine if a second unit is indicated.
PRBCs are only compatible with normal saline and cannot be run with other blood components. Blood warmers may be desired for transfusion in patients with massive hemorrhage or with cold antibodies.
Indicated in patients with confirmed IgA deficiency and anti-IgA antibodies in the presence of a history of a severe allergic reaction to a blood product. Washed PRBCs can also be tried for patients with repeated allergic reactions unresponsive to other measures (eg, premedication).
Washing PRBCs with 0.9% NaCl removes plasma proteins and a significant portion of leukocytes, platelets, and microaggregates.
PRBC, packed red blood cell.