How to order a blood transfusion for an adult patient with no known allergies?

How to Order Blood Transfusion for an Adult Patient with No Known Allergies

For a hemodynamically stable adult patient with no known allergies, order a single unit of packed red blood cells when hemoglobin is <7 g/dL (or <8 g/dL if cardiovascular disease is present), ensuring proper patient identification with at least two identifiers, obtaining appropriate blood samples, and monitoring vital signs before transfusion, at 15 minutes, and at completion. 1, 2

Pre-Transfusion Requirements

Patient Identification and Blood Sampling

• All patients receiving blood transfusion must wear a patient identification band with minimum identifiers: surname, forename, date of birth, and hospital unique identification number. 1
• Blood samples must be collected and labeled at the patient's bedside by appropriately trained personnel. 1
• Two samples are required unless a suitable "historical" sample exists on file with the same patient identification transmitted electronically with no manual intervention. 1
• If the patient received a transfusion or was pregnant within the previous 3 months, the sample is only valid for 72 hours from collection to subsequent transfusion. 1

Pre-Transfusion Assessment

• Review previous medical records to identify risk factors for organ ischemia (cardiorespiratory disease) and coagulopathy (warfarin, clopidogrel, aspirin use). 1
• Check for congenital or acquired blood disorders, use of vitamins or herbal supplements affecting coagulation, or previous drug exposures (e.g., aprotinin) that may cause allergic reactions. 1
• Review available laboratory results including hemoglobin, hematocrit, and coagulation profiles if appropriate. 1
• Inform patients of potential risks versus benefits of blood transfusion and elicit their preferences. 1

Transfusion Decision Thresholds

Standard Hemoglobin Thresholds

• For most hospitalized adults who are hemodynamically stable, consider transfusion when hemoglobin is <7 g/dL (strong recommendation). 2, 3
• For patients with preexisting cardiovascular disease, use a threshold of 8 g/dL. 4, 2
• For patients undergoing cardiac surgery, a threshold of 7.5 g/dL is appropriate. 2
• For patients undergoing orthopedic surgery, a threshold of 8 g/dL is appropriate. 2
• Hemoglobin >10 g/dL rarely requires transfusion and increases risks without providing benefit. 4, 3

Clinical Assessment Beyond Hemoglobin

• Never use hemoglobin level alone as a transfusion trigger; base decisions on evidence of hemorrhagic shock, hemodynamic instability, signs of inadequate oxygen delivery (chest pain, dyspnea, tachycardia, hypotension, altered mental status), duration and acuity of anemia, and intravascular volume status. 4, 3
• Monitor for end-organ ischemia including ST changes on ECG, chest pain, decreased urine output, elevated lactate, or reduced mixed venous oxygen saturation. 4
• Evaluate for active or ongoing blood loss such as surgical drains, gastrointestinal bleeding, or visible blood loss >1500 mL. 4

Transfusion Administration Protocol

Ordering and Administration

• Order and administer one unit of packed red blood cells at a time, then reassess clinical status and hemoglobin before administering additional units (single-unit transfusion strategy). 5, 4, 3
• One unit (approximately 300-350 mL) should be infused over 2-4 hours in hemodynamically stable patients, which equates to roughly 75-175 mL/hour. 5
• The transfusion must be completed within 4 hours of removal from temperature-controlled storage—this is a critical safety threshold to prevent bacterial proliferation and hemolysis. 5
• Time outside temperature-controlled environment should be restricted to 30 minutes before starting transfusion. 5
• Use a 170-200 μm filter for all RBC transfusions. 5

Vital Sign Monitoring Requirements

• Complete and document vital signs (pulse, blood pressure, temperature, and especially respiratory rate) before starting transfusion (within 60 minutes), at 15 minutes after starting each unit, and within 60 minutes of completion. 1, 5
• Respiratory rate monitoring is particularly critical as dyspnea and tachypnea are typical early symptoms of serious transfusion reactions. 1

Special Circumstances and Rate Adjustments

Slower Transfusion Rates

• For patients at risk of transfusion-associated circulatory overload (TACO)—including elderly patients (age >70 years), those with heart failure, renal failure, hypoalbuminemia, or low body weight—use slower transfusion rates, close monitoring of vital signs and fluid balance, and consider prophylactic diuretic prescribing. 1, 5

Faster Transfusion Rates

• For active hemorrhage, transfusion should be guided by hemodynamic response rather than fixed time intervals. 5
• In massive hemorrhage scenarios, rapid infusion through large-bore catheters with pressure devices can deliver units in under 1 minute when necessary. 5

Critical Pitfalls to Avoid

Timing and Storage

• The 4-hour clock begins when the unit leaves controlled storage, not when infusion starts—if transfusion is paused, do not restart the 4-hour clock. 5
• If an incorrect pump rate is discovered mid-transfusion, the unit does not need to be discarded provided total time out of storage remains under 4 hours and the patient shows no signs of transfusion reaction. 5

Transfusion Strategy Errors

• Avoid liberal transfusion strategies (transfusing to hemoglobin >10 g/dL) as they increase risks of nosocomial infections, multi-organ failure, TRALI, and transfusion-associated circulatory overload without providing benefit. 4, 3
• Do not order multiple units upfront; reassess need after each unit. 5
• Large numbers of RBC units should not be transferred with patients during intra-hospital transfer to avoid unnecessary wastage. 1

Adverse Reaction Management

• Transfusion-associated circulatory overload (TACO) is now the most common cause of transfusion-related mortality and major morbidity. 1
• For febrile reactions, only intravenous paracetamol may be required; for allergic reactions, only an antihistamine should be administered—do not use steroids and/or antihistamines indiscriminately. 1
• If severe reaction and/or anaphylaxis is suspected, follow local anaphylaxis protocols immediately. 1

Expected Outcomes

• One unit of packed red cells should increase hemoglobin by approximately 1-1.5 g/dL. 4
• Target a post-transfusion hemoglobin of 7-9 g/dL in most patients, as higher targets have not shown additional benefit. 4
• A restrictive transfusion strategy reduces transfusion exposure by approximately 40% without increasing mortality or adverse outcomes. 4, 3