Transfusion Therapy

Composition & storage: - Single donor; 250–300 mL; Hct ~70% - 1 unit adult → ↑ Hgb ~1 g/dL or Hct ~3% - 10 mL/kg pRBC → Hct +10% in peds - Stored at 4 °C in CPDA (35 d) or AS-1/AS-3 (Adsol, 42 d) - Always run with NS or Normosol on a blood-warming pump - DO NOT mix with LR (theoretical citrate-Ca clot) or D5W/hypotonic (hemolysis) - Run through a warmer (Ranger for slow, Belmont or Level 1 for rapid)

ASA indications: 1. Hgb < 6 in young healthy patients 2. Usually unnecessary if Hgb > 10 3. At Hgb 6–10, transfuse based on: - Ongoing organ ischemia - Potential for continued blood loss - Volume status - Risk factors for inadequate O₂ delivery (myocardial ischemia, advanced age, sepsis)

• Platelet Concentrate (PC): from one whole-blood donation. 50–70 mL; ↑ plt ~5,000–10,000.
• "6-pack": 6 pooled PCs; rarely used now.
• Apheresis unit: from one donor; 200–400 mL; ↑ plt ~50,000.

Storage: room temperature, 5 days. - Hang separately on blood pump with NS - Do NOT run through warmer (heating may injure platelets) - ABO-incompatible OK; Rh tested only (small RBC contamination — Rh sensitization possible)

ASA indications: 1. Rarely if plt > 100,000 2. Usually if plt < 50,000 (spontaneous bleed risk at < 20,000) 3. Between 50–100,000: based on bleeding risk 4. Platelet dysfunction (CPB, anti-platelets, uremia)

• Fluid fraction of whole blood; contains all coagulation factors except platelets
• 1 unit → ↑ clotting factors 2–3%
• ABO-compatible required; Rh-incompatible OK
• AB blood type is universal donor for plasma (universal recipient for RBCs)
• Frozen; ~30 min to thaw; use within 24 h of thawing

ASA indications: 1. Microvascular bleeding with INR > 2 2. Massive transfusion (before labs available) 3. Urgent reversal of warfarin (or PCC — prothrombin complex concentrate) 4. Known factor deficiency when concentrate unavailable 5. Heparin resistance (antithrombin III deficiency)

• Fraction that precipitates when FFP is thawed
• Contains factors I (fibrinogen), VIII, XIII, and vWF
• 1 unit contains ~5× more fibrinogen than 1 unit FFP
• 0.1 units/kg ≈ ↑ fibrinogen by 100 mg/dL
• Use within 4–6 h after thawing if you want Factor VIII

ASA indications: 1. Rarely if fibrinogen > 150 mg/dL 2. Fibrinogen < 100 mg/dL with microvascular bleeding 3. Massive transfusion when fibrinogen unknown 4. Bleeding patients with vWD 5. Congenital fibrinogen deficiency

Definition: > 1 blood volume (~10 units pRBC) in 24 h, OR > 4 units in 1 h with ongoing need.

Targets: - Hgb > 7 (8 if cardiac disease) - Platelets > 50,000 (100,000 if intracranial/ocular) - Fibrinogen > 150–200 mg/dL - INR < 1.5 - Ionized calcium > 1.1 mmol/L - Temperature > 36 °C - pH > 7.2

Strategy: - 1:1:1 RBC : FFP : platelets (early balanced resuscitation) - Tranexamic acid: 1 g over 10 min then 1 g over 8 h (within 3 h of injury) - Cryoprecipitate to keep fibrinogen > 150 (10 units in adult) - Calcium chloride 1 g per 4 units pRBC (citrate toxicity) - Active warming (forced air, fluid warmer) - Permissive hypotension (SBP 80–90) in non-TBI patients until source controlled

Arterial O₂ content: CaO₂ = (Hb × 1.36 × SaO₂) + (PaO₂ × 0.003) ≈ 20 mL O₂/dL (normal)

Allowable blood loss: ABL = (Hct_start − Hct_allowed) × EBV / Hct_start

Volume to transfuse: Volume = (Hct_desired − Hct_current) × EBV / Hct_transfused_blood

Estimated Blood Volume (mL/kg): | Group | EBV | |---|---| | Premie | 100 | | Term | 90 | | < 1 yr | 80 | | 1–6 yr | 75 | | Adult male | 70 | | Adult female | 65 | | Obese | 60 |

Acute hemolytic — ABO mismatch. Fever, chills, flank pain, hemoglobinuria, hypotension, DIC. Stop transfusion, supportive care, send sample to blood bank.

Febrile non-hemolytic — cytokines or anti-leukocyte antibodies. Treat with antipyretics; usually self-limited.

Allergic / urticarial — mild itching to anaphylaxis. Diphenhydramine for mild; epinephrine for severe.

TRALI (Transfusion-Related Acute Lung Injury) — 4–6 h after transfusion. Donor antibodies vs recipient leukocytes → pulmonary edema. Most common cause of transfusion-related mortality. Supportive care (often need MV).

TACO (Transfusion-Associated Circulatory Overload) — volume overload. Diuresis, slow rate, sit patient up.

Citrate toxicity — large volume citrated blood. Calcium binding → ↓ ionized Ca → hypotension, prolonged QT. Treat with CaCl₂.

Hyperkalemia — old blood, irradiated units, rapid transfusion in neonates. Check K, treat hyperkalemia per protocol.