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Blood Bank

Purchasing & Inventory

Effective inventory management in Blood Bank is a high-stakes balancing act between clinical safety and financial stewardship. Unlike Chemistry or Hematology, where reagents have long shelf lives, the primary inventory of Blood Bank (blood components) is highly perishable, scarce, and biologically variable. The goal of purchasing and inventory management is to ensure that adequate blood products and testing supplies are available to meet routine and emergency patient needs without incurring excessive financial loss due to outdating (wastage)

The Unique Nature of Blood Inventory

Blood product inventory management is distinct from general supply chain management due to the strict expiration limits and the inability to “manufacture” more product on demand

  • Perishability: Platelets expire in 5 to 7 days; Red Blood Cells (RBCs) in 35 to 42 days; Thawed Plasma in 24 hours to 5 days. This rapid decay necessitates a rigorous First-In, First-Out (FIFO) rotation policy
  • Biologic Variability: Not all “Group A” units are the same. Inventory managers must account for special antigen profiles (e.g., C/c/E/K negative units for Sickle Cell patients) and CMV-negative units for neonates
  • Supplier Dependence: The laboratory relies on external Blood Centers (e.g., Red Cross, Vitalant). Supply is dictated by donor turnout, not factory production. During shortages, Blood Bank may place an order for 20 units but only receive 10, requiring dynamic triage protocols

Purchasing Strategies

Purchasing involves the acquisition of both biological products and testing materials. Different strategies are employed to optimize costs and workflow

Standing Orders vs. Ad-Hoc Ordering

  • Standing Orders: A pre-negotiated agreement where the Blood Center automatically ships a specific mix of blood products to the hospital daily or weekly
    • Benefit: Guarantees a baseline inventory and reduces the administrative burden of calling in daily orders
    • Risk: Can lead to overstocking if patient census drops unexpectedly
  • Ad-Hoc (Stat) Orders: Orders placed to replenish specific shortages or for specific patient needs (e.g., an HLA-matched platelet)
    • Cost Implication: These often incur “Stat Fees” or expensive courier charges, so they should be minimized through better forecasting

Reagent Sequestering

For testing reagents (Anti-A, Anti-B, Screening Cells), consistency is vital for Quality Control (QC)

  • The Concept: The laboratory commits to purchasing a large volume of a specific lot number of reagent. The manufacturer sets this lot aside (“sequesters” it) in their warehouse and ships portions of it monthly
  • Financial and Operational Benefit: The lab performs the “New Lot Validation” (crossover study) only once per year rather than every month. This saves significant labor hours and expensive reagent waste associated with frequent QC calibration

Group Purchasing Organizations (GPOs)

Most hospitals belong to a GPO. This entity aggregates the purchasing power of hundreds of hospitals to negotiate lower prices with vendors (e.g., Immucor, Ortho, Bio-Rad)

  • Compliance: The laboratory is often restricted to buying from vendors on the GPO contract to maintain the discount pricing

Inventory Control Models

To maintain the correct amount of stock, laboratories use mathematical and logical models to determine when to order and how much to order

Par Levels (Min/Max)

  • Minimum (Reorder Point): The inventory level that triggers an order. This number must be high enough to cover usage during the “Lead Time” (the time between placing the order and the truck arriving)
    • Example: If you use 10 O-Positive units a day and it takes 1 day to get blood, your Min might be 15 units
  • Maximum (Par): The upper limit of inventory. Exceeding this increases the risk of expiration
  • Calculation: These levels are calculated based on Historical Usage Data. A Trauma Center will have much higher Par levels than a community hospital

Safety Stock (Buffer Stock)

An extra quantity of inventory held to protect against fluctuations in demand (e.g., a Mass Casualty Incident) or supply chain delays (e.g., a blizzard stopping courier trucks)

  • Blood Bank Specifics: Safety stock is critical for O-Negative RBCs (Universal Donor) and AB Plasma (Universal Donor), as these are the first products consumed in an uncrossmatched emergency

Receipt & Inspection Regulations

Regulatory agencies (FDA, AABB, CAP) mandate strict inspection processes upon the receipt of goods. This is the first line of defense against financial loss (paying for damaged goods) and patient harm

  • Temperature Check: Every shipment of blood must have its temperature verified upon arrival
    • RBCs: \(1-10^\circ\text{C}\)
    • Platelets: \(20-24^\circ\text{C}\)
    • Frozen Products: Dry ice must still be present
    • Action: If out of range, the shipment is rejected, and credit is requested from the supplier immediately
  • Visual Inspection: Units must be inspected for hemolysis, discoloration, clots, or bag port integrity issues
  • Reagent Verification
    • Date Received: Must be written on the box
    • Date Opened: Must be written on the vial when put into use to track “open-vial stability.”

Managing Wastage & Returns

Wastage (outdating) is a major financial metric. Blood products are expensive assets; letting them expire is equivalent to throwing cash in the trash

The Return Policy

Some Blood Center contracts allow for a “Return Credit.”

  • Short-Dated Returns: If the hospital realizes they cannot use a unit before it expires, they may return it to the supplier before the expiration date (e.g., with 5 days remaining)
  • Financial Credit: The supplier may credit the hospital (e.g., 50% of the cost) and redistribute the unit to a larger, high-volume Trauma Center where it will be used immediately
  • Condition: The unit must have been stored continuously at the correct temperature, and strict temperature logs must accompany the return to prove the “Cold Chain” was never broken

Internal Rotation

Within a hospital system, inventory is often rotated

  • Satellite to Hub: A small community hospital will keep units until they have 10 days of shelf-life left, then ship them to the main university hospital (the “Hub”) where the high surgical volume ensures they are used before expiration

Inventory “Tying”

This refers to how long a unit is crossmatched (reserved) for a specific patient

  • Problem: If a unit is crossmatched for Patient A for 3 days, it cannot be used for anyone else. If Patient A doesn’t use it, the unit sits idle, aging
  • Solution: Strict “Maximum Surgical Blood Order Schedules” (MSBOS) and short crossmatch release policies (e.g., releasing units after 24 hours) keep the inventory fluid and available for use, reducing the need to purchase excess stock