Optimize Preop | Minimize Blood Loss | Transfuse Appropriately
PATIENT BLOOD MANAGEMENT PILLARS
Critical Must-Knows
- Preoperative anemia (Hb less than 130 g/L men, less than 120 g/L women) increases transfusion risk 3-4 fold
- Tranexamic acid (TXA) 15-20 mg/kg IV reduces transfusion by 30-50% without increasing VTE
- Restrictive transfusion threshold (Hb less than 70 g/L) is safe and reduces complications vs liberal (less than 100 g/L)
- Cell salvage contraindicated in malignancy, infection, bowel contamination
- Massive transfusion protocol: 1:1:1 ratio RBC:FFP:Platelets to prevent dilutional coagulopathy
Clinical Pearls
- "CRASH-2 trial: TXA within 3h of trauma reduces mortality (not just blood loss)
- "Iron therapy takes 4-6 weeks - plan elective surgery timing accordingly
- "Jehovah's Witness patients: multi-modal approach (EPO, TXA, cell salvage, accept lower Hb)
- "Hypotensive anesthesia (MAP 50-60 mmHg) reduces blood loss but requires experienced anesthetist
Clinical Imaging
Perioperative Blood Management
Critical Exam Concepts
Preoperative Anemia is Modifiable
Screen ALL elective patients. Hb less than 130 g/L (men) or less than 120 g/L (women) = anemia. Treat with oral iron 4-6 weeks preop or IV iron if time limited. EPO if renal failure or severe anemia.
TXA is Evidence-Based Standard
Give TXA to ALL major ortho cases unless contraindicated. Loading dose 15-20 mg/kg IV at induction, maintenance 1-2 mg/kg/h. CRASH-2 showed mortality benefit in trauma.
Restrictive Threshold is Safe
Transfuse at Hb less than 70 g/L (asymptomatic stable patients). Higher threshold (less than 80 g/L) if cardiovascular disease or symptomatic. Liberal transfusion increases complications.
Jehovah's Witness Management
Multi-modal approach: EPO preop, TXA, cell salvage (if acceptable), meticulous hemostasis, hypotensive anesthesia, accept Hb 60-70 g/L. Document consent clearly.
Blood Management Strategy Quick Reference
| Strategy | Timing | Evidence/Effect | Key Considerations |
|---|---|---|---|
| Oral iron therapy | 4-6 weeks preop | Increases Hb by 10-20 g/L | Need time - not effective if less than 2 weeks |
| IV iron (ferric carboxymaltose) | 1-2 weeks preop | Rapid Hb increase 10-30 g/L | More expensive, use if time limited |
| Erythropoietin (EPO) | 3-4 weeks preop | Increases Hb 20-40 g/L with iron | Expensive, renal failure or severe anemia |
| Tranexamic acid (TXA) | At induction and intraop | 30-50% reduction in transfusion | Safe, no VTE increase, give to all major cases |
| Cell salvage | Intraoperative | Reduces allogeneic transfusion 30-40% | Contraindicated: malignancy, infection, bowel |
| Hypotensive anesthesia | Intraoperative | Reduces blood loss 20-30% | MAP 50-60 mmHg, requires experienced anesthetist |
OPTPatient Blood Management Pillars
| O | Optimize Optimize hemoglobin preoperatively (screen, iron, EPO) |
| P | Protect Protect blood volume intraoperatively (TXA, cell salvage, technique) |
| T | Transfuse appropriately Transfuse based on restrictive thresholds (Hb less than 70 g/L) |
| O | Optimize Optimize hemoglobin preoperatively (screen, iron, EPO) |
| P | Protect Protect blood volume intraoperatively (TXA, cell salvage, technique) |
| T | Transfuse appropriately Transfuse based on restrictive thresholds (Hb less than 70 g/L) |
Hook:OPT for optimal blood management - optimize preop, protect intraop, transfuse appropriately!
CRASHTranexamic Acid Indications
| C | Cardiac surgery Reduces transfusion in CABG, valve replacement |
| R | Revision arthroplasty Higher blood loss - TXA highly effective |
| A | Arthroplasty primary THA, TKA standard - reduces transfusion 30-50% |
| S | Spine surgery Multi-level fusion, deformity correction |
| H | Hip fracture CRASH-2 trial showed mortality benefit in trauma |
| C | Cardiac surgery Reduces transfusion in CABG, valve replacement | S | Spine surgery Multi-level fusion, deformity correction |
| R | Revision arthroplasty Higher blood loss - TXA highly effective | H | Hip fracture CRASH-2 trial showed mortality benefit in trauma |
| A | Arthroplasty primary THA, TKA standard - reduces transfusion 30-50% |
Hook:Think of CRASH-2 trial - TXA saves lives in trauma and reduces transfusion in elective ortho!
MIBCell Salvage Contraindications
| M | Malignancy Risk of tumor cell dissemination (absolute contraindication) |
| I | Infection Risk of sepsis from reinfusing contaminated blood |
| B | Bowel contamination GI content contamination (pelvic fractures with bowel injury) |
| M | Malignancy Risk of tumor cell dissemination (absolute contraindication) |
| I | Infection Risk of sepsis from reinfusing contaminated blood |
| B | Bowel contamination GI content contamination (pelvic fractures with bowel injury) |
Hook:MIB are absolute contraindications - Malignancy, Infection, Bowel contamination - do NOT salvage!
RATIOMassive Transfusion Protocol Components
| R | RBC Red blood cells - 1 unit |
| A | All components equal Equal ratio prevents dilutional coagulopathy |
| T | Thawed FFP Fresh frozen plasma - 1 unit |
| I | Immediate platelets Platelet concentrate - 1 unit |
| O | O negative if unknown Use O neg RBC if type unknown, switch when available |
| R | RBC Red blood cells - 1 unit | I | Immediate platelets Platelet concentrate - 1 unit |
| A | All components equal Equal ratio prevents dilutional coagulopathy | O | O negative if unknown Use O neg RBC if type unknown, switch when available |
| T | Thawed FFP Fresh frozen plasma - 1 unit |
Hook:Remember RATIO 1:1:1 for massive transfusion - RBC:FFP:Platelets in equal amounts!
Overview and Clinical Significance
Patient Blood Management Paradigm Shift
The Patient Blood Management (PBM) approach has replaced the old "type and cross" reactive model. PBM is proactive: detect and treat anemia BEFORE surgery, minimize blood loss DURING surgery, and transfuse appropriately AFTER surgery. This reduces transfusion rates by 30-50% and improves outcomes.
Why Blood Management Matters
- Preoperative anemia present in 30-40% elective ortho patients
- Anemia increases transfusion risk 3-4 fold
- Allogeneic transfusion increases infection, LOS, mortality
- Blood is scarce resource - donor shortages worldwide
- Cost - 1 unit RBC costs $500-1000 AUD including administration
Three Pillars of Patient Blood Management
- Optimize hematopoiesis - detect and treat preop anemia
- Minimize blood loss - surgical technique, TXA, cell salvage
- Harness physiologic reserve - restrictive transfusion thresholds
WHO and NHMRC endorsed approach
Transfusion Risks
Allogeneic blood transfusion is NOT benign. Risks include acute hemolytic reaction (1:40,000), transfusion-related acute lung injury (TRALI 1:10,000), infection transmission (very low with modern screening), immunosuppression, and increased surgical site infection.
Pathophysiology
Physiology of Hemostasis
Coagulation Cascade:
- Intrinsic pathway: Contact activation (XII → XI → IX → VIII → X)
- Extrinsic pathway: Tissue factor exposure (VII → X) - primary initiator in surgical bleeding
- Common pathway: X → V → thrombin → fibrinogen → fibrin clot
- Fibrinolysis: Plasminogen → plasmin → fibrin degradation (target of TXA)
Physiological Response to Blood Loss:
| Blood Loss | Hemodynamic Changes | Symptoms |
|---|---|---|
| Class I (up to 15%) | Minimal | None - compensated |
| Class II (15-30%) | Tachycardia, narrow pulse pressure | Anxiety, delayed capillary refill |
| Class III (30-40%) | Tachycardia, hypotension, tachypnea | Confusion, decreased urine output |
| Class IV (greater than 40%) | Severe hypotension, absent pulses | Lethargy, anuria, impending death |
Oxygen Delivery Physiology
Oxygen Delivery Equation: DO₂ = CO × CaO₂ = CO × (1.34 × Hb × SaO₂ + 0.003 × PaO₂)
Key Concepts:
- Hemoglobin is the primary oxygen carrier (1.34 mL Oâ‚‚/g Hb)
- Normal DOâ‚‚: 900-1100 mL/min; VOâ‚‚: 200-250 mL/min
- Critical DOâ‚‚: ~300 mL/min - below this, anaerobic metabolism ensues
- Compensatory mechanisms: increased cardiac output, oxygen extraction ratio
- Young healthy patients tolerate Hb 70 g/L due to compensation; elderly/cardiac patients less so
Impact of Anemia on Surgical Outcomes
Preoperative Anemia Effects:
- Increased 30-day mortality (OR 1.4-2.9 depending on severity)
- Increased postoperative complications (infections, AKI, cardiac events)
- Increased length of stay and readmission rates
- Often triggers transfusion, which compounds risks
Perioperative Coagulopathy:
- Hypothermia impairs enzyme function in coagulation cascade
- Acidosis reduces clotting factor activity (pH 7.2 = 50% activity)
- Hemodilution from crystalloid/colloid resuscitation
- Consumption coagulopathy in massive hemorrhage
- Lethal triad: Hypothermia + acidosis + coagulopathy
Differential Diagnosis
When a surgical patient is anaemic preoperatively or bleeding unexpectedly, the cause must be characterised before it can be treated. The two key differentials are the type of anaemia (which directs optimisation) and the cause of intraoperative coagulopathy (which directs product choice).
Differential Diagnosis of Preoperative Anaemia
| Category | Clue (indices/labs) | Typical Causes | Key Action |
|---|---|---|---|
| Microcytic (MCV less than 80 fL) | Low ferritin, low transferrin saturation | Iron deficiency, thalassaemia trait | Treat iron deficiency; check ferritin to exclude thalassaemia |
| Normocytic (MCV 80-100 fL) | Normal/high ferritin, raised CRP | Anaemia of chronic disease/inflammation, renal impairment, acute blood loss | Treat underlying disease; consider IV iron plus ESA if renal |
| Macrocytic (MCV greater than 100 fL) | Low B12/folate, abnormal LFTs | B12/folate deficiency, alcohol, hypothyroidism, myelodysplasia | Replace B12/folate; investigate marrow if unexplained |
| Haemolytic | Raised LDH/bilirubin, low haptoglobin, positive DAT | Autoimmune, hereditary spherocytosis, drug-induced | Haematology referral; caution with transfusion crossmatch |
Differential Diagnosis of Unexpected Intraoperative Bleeding
| Mechanism | Distinguishing Feature | Targeted Treatment |
|---|---|---|
| Surgical (mechanical) bleeding | Discrete bleeding point; normal coagulation | Direct haemostasis - the primary remedy |
| Dilutional coagulopathy | Diffuse ooze after large-volume resuscitation | Balanced FFP/platelets (1:1:1), limit crystalloid |
| Hyperfibrinolysis | Clot lysis on viscoelastic testing (ROTEM/TEG) | Tranexamic acid |
| Hypofibrinogenaemia | Fibrinogen less than 1.5 g/L | Cryoprecipitate or fibrinogen concentrate |
| Residual anticoagulation | Drug history; raised INR/aPTT/anti-Xa | Reverse: PCC/vitamin K (warfarin), specific agents for DOACs |
| Hypothermia/acidosis | Core temp less than 35C, pH less than 7.2 with ooze | Active warming, correct acidosis, restore perfusion |
Pillar 1: Preoperative Optimization
Preoperative Anemia Screening
WHO Definition of Anemia:
- Men: Hb less than 130 g/L
- Women: Hb less than 120 g/L
- Pregnancy: Hb less than 110 g/L
Screen ALL Elective Patients
Australian NHMRC guidelines recommend screening hemoglobin and ferritin for ALL patients undergoing elective surgery with expected moderate-high blood loss (greater than 500 mL). This includes most major orthopaedic procedures.
| Test | Interpretation | Action |
|---|---|---|
| Hb less than 130/120 g/L | Anemia present | Investigate cause, treat 4-6 weeks preop |
| Ferritin less than 30 mcg/L | Iron deficiency anemia | Oral iron 200 mg elemental iron daily |
| Ferritin 30-100 mcg/L | Functional iron deficiency | Consider IV iron if time limited |
| MCV less than 80 fL | Microcytic anemia | Iron deficiency vs thalassemia - check ferritin |
| MCV greater than 100 fL | Macrocytic anemia | B12/folate deficiency - supplement |
Anemia Workup in Orthopaedics
Most common causes in elective ortho patients: (1) iron deficiency (chronic blood loss, poor intake), (2) anemia of chronic disease (inflammatory arthritis), (3) renal impairment (hip OA patients often elderly with CKD). Check FBC, ferritin, CRP, creatinine as minimum.
This completes the screening protocol overview.
Pillar 2: Minimize Intraoperative Blood Loss
Tranexamic Acid (TXA) - Evidence and Protocols
TXA Mechanism of Action
TXA is a lysine analogue that competitively inhibits plasminogen activation, preventing fibrinolysis. It stabilizes formed clot by blocking plasmin from degrading fibrin. Effect lasts 3-4 hours. Does NOT increase clot formation (not pro-thrombotic), just prevents clot breakdown.
TXA Dosing Regimens:
| Procedure | Loading Dose | Maintenance | Timing |
|---|---|---|---|
| Primary THA/TKA | 15-20 mg/kg IV | Optional 1-2 mg/kg/h infusion | At induction before tourniquet |
| Revision THA/TKA | 20 mg/kg IV | 2 mg/kg/h for 3-6 hours | At induction, continue postop |
| Spine surgery | 10-15 mg/kg IV | 1 mg/kg/h for duration | At incision, throughout case |
| Trauma (CRASH-2) | 1 g IV bolus | 1 g IV over 8 hours | Within 3 hours of injury (critical) |
| Topical (intra-articular) | 1-3 g in 50-100 mL saline | Leave in joint 5 min before closure | At closure before drain placement |
CRASH-2 Trial Changed Practice
The CRASH-2 trial (20,211 trauma patients) showed TXA within 3 hours of injury reduced all-cause mortality from 16% to 14.5% (NNT=67). Given between 3-8 hours, NO benefit. After 8 hours, HARM (increased mortality). Time is critical in trauma.
TXA Contraindications:
- Active thromboembolic disease (DVT, PE, MI, stroke less than 3 months)
- History of seizures (TXA crosses BBB, rare seizure risk at high doses)
- Known allergy to TXA
- Renal impairment (reduce dose if CrCl less than 30 - risk of accumulation)
TXA Safety Profile
Multiple meta-analyses (over 100 RCTs) show TXA does NOT increase VTE, MI, or stroke rates in orthopaedic surgery. It is safe and effective. The theoretical thrombosis risk is not seen in practice. Give TXA to ALL major ortho cases unless contraindicated.
This completes the tranexamic acid section.
Pillar 3: Appropriate Transfusion Management
Restrictive vs Liberal Transfusion Thresholds
Paradigm Shift to Restrictive Strategy
The TRICC trial (1999) and multiple subsequent trials showed restrictive transfusion (Hb less than 70 g/L) is as safe as liberal (Hb less than 100 g/L) and reduces transfusion-related complications. This changed practice worldwide. Liberal transfusion does NOT improve outcomes and increases infection and mortality.
Transfusion Thresholds by Patient Population
| Patient Type | Transfusion Threshold | Evidence |
|---|---|---|
| Healthy, asymptomatic | Hb less than 70 g/L | TRICC, FOCUS trials - safe, reduces transfusion |
| Cardiovascular disease | Hb less than 80 g/L | Subset analysis suggests higher threshold safer |
| Acute coronary syndrome | Hb less than 80 g/L or symptoms | MINT trial - restrictive non-inferior |
| Symptomatic anemia | Symptoms (dyspnea, tachycardia, angina) | Transfuse for symptoms regardless of Hb |
| Active bleeding | Transfuse to maintain Hb greater than 70-80 g/L | Replace ongoing losses |
Symptoms Trump Numbers
Transfusion triggers are GUIDELINES, not absolutes. Symptoms of anemia (dyspnea, tachycardia, chest pain, confusion) are indication for transfusion regardless of Hb. Patient with Hb 75 g/L who is asymptomatic does NOT need transfusion. Patient with Hb 85 g/L with angina DOES need transfusion.
Signs/Symptoms Suggesting Need for Transfusion:
- Tachycardia (HR greater than 100 at rest) not explained by pain/anxiety
- Dyspnea or increased work of breathing
- Chest pain or ECG changes (ischemia)
- Postural hypotension or dizziness
- Confusion or altered mental state
- Oliguria (less than 0.5 mL/kg/h)
This completes the transfusion threshold section.
Jehovah's Witness Patient Management
Jehovah's Witness Beliefs
Jehovah's Witness patients refuse allogeneic blood transfusion (RBC, FFP, platelets) based on religious beliefs. However, acceptance of other strategies varies individually: many accept cell salvage (if continuous circuit), EPO, TXA, albumin. Must discuss and document individual preferences preoperatively. Do NOT assume all refuse all products.
Usually Acceptable
- Erythropoietin (EPO) preoperatively
- Tranexamic acid (TXA)
- Cell salvage (if continuous circuit)
- Crystalloid and colloid (albumin often accepted)
- Hypotensive anesthesia
- Iron supplementation (oral or IV)
- Accepting lower Hb (60-70 g/L) postoperatively
Usually Refused
- Allogeneic RBC transfusion
- Fresh frozen plasma (FFP)
- Platelet transfusion
- Cryoprecipitate
- Whole blood
- Some refuse cell salvage if circuit is not continuous
- Some refuse albumin or factor concentrates
Multi-Modal Blood Management Strategy:
Preoperative optimization - screen Hb, start EPO 40,000 units weekly x 4 + IV iron 1000 mg. Goal: Hb greater than 140 g/L preop.
Document preferences - which products acceptable (cell salvage, EPO, TXA, albumin?). Document in chart and consent. Discuss acceptable minimum Hb (usually 60-70 g/L).
Minimize blood loss - meticulous hemostasis, TXA (20 mg/kg load + infusion), cell salvage, hypotensive anesthesia, consider staged procedures if bilateral.
Accept lower Hb - most Jehovah's Witness patients tolerate Hb 60-70 g/L. Continue EPO postop if needed, supplemental oxygen, mobilize early, recheck Hb daily.
Informed Consent and Documentation
Obtain informed consent documenting patient refuses transfusion even if life-threatening. Have patient sign specific Jehovah's Witness refusal form. Document discussion of risks (including death) if severe blood loss occurs. Consider having witness to consent. Respect patient autonomy.
When to Refuse Surgery
If Jehovah's Witness patient presents for high blood loss procedure (revision THA, spine tumor resection) with preop Hb less than 100 g/L and refuses transfusion, consider: (1) delay surgery to optimize with EPO + iron (if elective), (2) frank discussion of mortality risk, (3) may need to refuse surgery if risk unacceptable. Document decision-making thoroughly.
Guidelines, Registries and Global Practice
Convergent International Consensus
Across the major guideline bodies the message is remarkably consistent: screen and treat preoperative anaemia, give tranexamic acid, use cell salvage for high-loss cases, and transfuse restrictively (single-unit, Hb-triggered). Patient Blood Management (PBM) is endorsed by the WHO as a global standard of care. The principal differences between countries lie in funding/reimbursement of IV iron and erythropoiesis-stimulating agents, not in the core clinical recommendations.
Global Epidemiology
Burden of Preoperative Anaemia
- Present in approximately 30% of major non-cardiac surgical patients worldwide (227,425-patient NSQIP cohort)
- Independently raises 30-day mortality (adjusted OR 1.42) and morbidity (OR 1.35)
- In elective hip and knee arthroplasty, reported prevalence ranges roughly 15-40%, driven by iron deficiency and anaemia of inflammation
- Anaemia is the strongest modifiable predictor of perioperative allogeneic transfusion
Transfusion and Blood Supply
- Allogeneic red cells are a finite, donor-dependent resource with periodic shortages in most health systems
- O-negative (universal donor) is chronically scarce - only about 7-9% of most populations
- PBM programmes reduce red-cell utilisation by 20-40% without harm
- Low- and middle-income countries face the greatest supply constraints, magnifying the value of TXA and cell salvage
Side-by-Side Guideline Comparison
Major Guideline Positions on Perioperative Blood Management
| Body (Region) | Anaemia / Iron | Tranexamic Acid | Transfusion Threshold |
|---|---|---|---|
| WHO (global) | Endorses PBM; treat anaemia preop | Supports antifibrinolytics | Restrictive, evidence-based triggers |
| NBA / NHMRC (Australia) | Screen and treat all elective major surgery | Recommended (cell salvage too) | Restrictive; transfuse for Hb less than 70 g/L or symptoms |
| NICE NG24 (UK) | Offer iron before/after surgery if iron-deficient | Offer TXA for expected major blood loss | Threshold Hb 70 g/L (80 g/L if ACS); single-unit |
| AABB (USA, 2023) | PBM and anaemia management endorsed | Supported in surgery | Restrictive 70 g/L (75 g/L cardiac surgery) |
| ESA / ESAIC (Europe) | Detect and treat iron-deficiency anaemia | Strongly recommended | Restrictive; individualise in cardiac disease |
| EFORT / national ortho bodies | Preop optimisation pathway for arthroplasty | Routine in THA/TKA unless contraindicated | Restrictive, symptom-guided |
Evidence Level Behind the Guidance
The recommendations for TXA (Level I, multiple meta-analyses and CRASH-2) and restrictive transfusion (Level I, TRICC/FOCUS and the Cochrane transfusion-threshold review) are among the most robust in perioperative medicine. Preoperative anaemia treatment rests largely on high-quality observational data (Musallam) plus RCTs of IV iron with more variable transfusion-outcome effects, hence guideline wording is often "offer/consider" rather than "must".
Registry and Programme-Level Evidence
- National PBM programmes (e.g. Western Australia's statewide programme) have reported large reductions in red-cell, plasma and platelet use alongside reduced length of stay and in-hospital mortality - the strongest real-world endorsement of PBM.
- Arthroplasty registries (AOANJRR, NJR, AJRR) do not collect transfusion as a core variable but track the revision and infection outcomes that transfusion-associated immunomodulation can influence, reinforcing the rationale for blood conservation.
Practice Variation
- IV iron and ESA funding differ markedly: many systems restrict erythropoiesis-stimulating agents to chronic kidney disease and chemotherapy, leaving elective-surgery use hospital- or patient-funded.
- Topical versus intravenous TXA preference varies by unit; both are effective, with combined regimens used in some high-loss cases.
- Cell salvage availability is resource-dependent and concentrated in higher-volume centres.
Regional Context: Australia and New Zealand
- NBA PBM Guidelines (Module 2: Perioperative) are the national standard, supported by ANZCA and ANZSBT position statements; eTG covers related perioperative prescribing.
- TXA is widely available and inexpensive. IV iron (ferric carboxymaltose) is funded for iron-deficiency anaemia (authority requirements apply); erythropoiesis-stimulating agents are reimbursed for renal and oncology indications but generally not for elective orthopaedic anaemia, where they are hospital- or self-funded.
Blood Supply Drives PBM
Most national blood services rely on voluntary, non-remunerated donors and issue periodic shortage alerts. This finite supply - not just patient outcomes - is a core driver of Patient Blood Management: conserve product, transfuse appropriately, and minimise waste.
Key Evidence and Trials
CRASH-2 Trial (2010)
- All-cause mortality 16.0% to 14.5% (RR 0.91, p=0.0035)
- Greatest benefit when given within 3 hours of injury
- No excess myocardial infarction, stroke or thromboembolism
- Dosing: 1 g bolus then 1 g over 8 hours
TRICC Trial (1999)
- Restrictive threshold 70 g/L vs liberal 100 g/L
- 30-day mortality 18.7% vs 23.3% (not significant)
- Restrictive at least as effective and possibly superior
- Possible exception: acute MI / unstable angina
FOCUS Trial (2011)
- Largest transfusion RCT in orthopaedic (hip-fracture) patients
- Restrictive threshold approx 80 g/L (or symptoms)
- No difference in death or independent walking at 60 days
- Restrictive strategy safe even in high cardiovascular-risk elderly
Preoperative Anaemia and Surgical Outcomes (2011)
- Preoperative anaemia present in ~30% of surgical patients
- 30-day mortality OR 1.42 (1.31-1.54) after adjustment
- Even mild anaemia is independently harmful
- Justifies routine preoperative anaemia screening
IV TXA Safety in Major Orthopaedic Surgery (2018)
- 73 RCTs in major orthopaedic surgery
- VTE 2.1% (TXA) vs 2.0% (control) - not significant (RR 1.067)
- Confirms TXA reduces blood loss and transfusion safely
- Supports routine intravenous TXA in arthroplasty
National Blood Authority Patient Blood Management Guidelines (Module 2: Perioperative)
- Three pillars: optimise red-cell mass, minimise blood loss, manage anaemia/tolerance
- Routine preoperative anaemia screening and treatment
- TXA and cell salvage recommended
- Restrictive transfusion thresholds endorsed
Exam Viva Scenarios
Use these scenarios to practise clinical reasoning and management decisions
Scenario 1: Preoperative Anemia in Elective TKA
"A 72-year-old woman is listed for elective TKA in 6 weeks. Preoperative Hb is 105 g/L, ferritin 18 mcg/L, CrCl 55 mL/min. How would you manage her preoperatively?"
Scenario 2: Massive Hemorrhage During Revision THA
"You are performing revision THA for aseptic loosening. During acetabular component removal, the patient develops massive hemorrhage from pelvic vessels. BP drops to 70/40, HR 130. Anesthetist estimates 2L blood loss in 10 minutes. How do you manage this?"
Scenario 3: Jehovah's Witness Patient for Bilateral TKA
"A 68-year-old Jehovah's Witness patient presents for bilateral TKA. Preoperative Hb is 118 g/L. She refuses all blood products. How would you counsel and manage this patient?"
MCQ Practice Points
Clinical Pearl
Q: What is the evidence-based transfusion threshold for hemodynamically stable patients following major orthopaedic surgery?
A: Hb 70 g/L (7 g/dL) for most patients. The FOCUS, TRACS, and TRICC trials demonstrated no benefit of liberal (100 g/L) over restrictive (70-80 g/L) transfusion thresholds. Exceptions requiring higher thresholds (80-100 g/L): acute coronary syndrome, symptomatic anaemia, ongoing significant bleeding. Single unit transfusion is appropriate unless ongoing hemorrhage.
Clinical Pearl
Q: What dose of tranexamic acid (TXA) is recommended for total joint arthroplasty and what is its mechanism?
A: 1-2g IV given preoperatively (10-15mg/kg), with optional repeat dose at wound closure. TXA is an antifibrinolytic that competitively inhibits plasminogen activation, preventing clot breakdown. Reduces blood loss by 30-50% and transfusion risk by 50%. Contraindicated in active thromboembolic disease. NOT contraindicated in patients with DVT/PE history with adequate thromboprophylaxis.
Clinical Pearl
Q: What are the key elements of a Patient Blood Management (PBM) program in orthopaedic surgery?
A: Three pillars: (1) Optimize red cell mass preoperatively - treat iron deficiency (IV iron if Hb under 130), EPO in selected cases. (2) Minimize blood loss - surgical technique, TXA, controlled hypotension, cell salvage. (3) Optimize physiological tolerance - restrictive transfusion thresholds, multimodal analgesia, early mobilization. The Australian National Blood Authority has specific PBM guidelines for surgery.
Clinical Pearl
Q: When is intraoperative cell salvage indicated in orthopaedic surgery?
A: Expected blood loss greater than 1000-1500mL (or anticipated need for greater than 2 units allogeneic blood). Common indications: revision arthroplasty, major spine surgery, pelvic/acetabular trauma, bilateral TKA. Cell salvage reinfuses the patient's own washed red cells. Contraindicated in malignancy (relative) and infection (absolute). Processing removes activated clotting factors.
Clinical Pearl
Q: What is the recommended management of anticoagulation in a patient on warfarin requiring urgent hip fracture surgery?
A: Reverse with IV Vitamin K 5-10mg + Prothrombinex-VF (25-50 IU/kg) for INR greater than 1.5. Surgery can proceed once INR under 1.5. Fresh frozen plasma (FFP) is second-line if Prothrombinex unavailable. Do NOT delay surgery more than 48 hours waiting for INR to normalize with vitamin K alone. Bridging with LMWH is NOT recommended for most hip fracture patients.
BLOOD MANAGEMENT STRATEGIES - EXAM CHEAT SHEET
Clinical summary
Three Pillars of Patient Blood Management
- •**Pillar 1: Optimize** - Detect and treat preop anemia (iron, EPO)
- •**Pillar 2: Minimize** - Reduce intraop blood loss (TXA, cell salvage, technique)
- •**Pillar 3: Manage** - Appropriate transfusion (restrictive threshold Hb less than 70 g/L)
Preoperative Anemia Management
- •**Screen:** Hb less than 130 g/L (men), less than 120 g/L (women) = anemia. Check ferritin, CRP, creatinine
- •**Oral iron:** 200 mg elemental iron daily x 4-6 weeks (increases Hb 10-20 g/L)
- •**IV iron:** Ferric carboxymaltose 1000 mg single dose (increases Hb 10-30 g/L in 1-2 weeks) - use if time limited
- •**EPO:** 40,000 units SC weekly x 3-4 weeks + iron (increases Hb 20-40 g/L) - CKD, severe anemia, Jehovah's Witness
- •**Recheck Hb** 1 week preop to confirm response
Tranexamic Acid (TXA)
- •**Mechanism:** Inhibits plasminogen activation, prevents fibrinolysis, stabilizes clot
- •**Dosing:** 15-20 mg/kg IV load at induction, optional 1-2 mg/kg/h maintenance
- •**Evidence:** 30-50% reduction in transfusion, NO increase in VTE/MI/stroke
- •**CRASH-2:** 1g bolus + 1g over 8h in trauma - reduces mortality if given within 3h
- •**Use:** All major ortho cases (THA, TKA, spine, trauma) unless contraindicated
Cell Salvage
- •**Indications:** Expected blood loss greater than 500-1000 mL (revision THA/TKA, spine, pelvis)
- •**Mechanism:** Collects shed blood, washes RBCs, reinfuses autologous Hct 50-60%
- •**Contraindications (MIB):** Malignancy, Infection, Bowel contamination (all absolute)
- •**Effect:** 30-40% reduction in allogeneic transfusion
- •**Jehovah's Witness:** Many accept if continuous circuit
Transfusion Thresholds
- •**Restrictive:** Hb less than 70 g/L (asymptomatic stable patients) - SAFE and reduces complications
- •**Liberal:** Hb less than 100 g/L (old practice) - NO benefit, increases complications
- •**Cardiovascular disease:** Threshold Hb less than 80 g/L (slightly higher)
- •**Symptomatic anemia:** Transfuse for symptoms (dyspnea, tachycardia, angina) regardless of Hb
- •**Evidence:** TRICC, FOCUS trials - restrictive is as safe as liberal with less transfusions
Massive Transfusion Protocol
- •**Definition:** Loss of 1 blood volume in 24h OR greater than 4 units in 1h
- •**1:1:1 ratio:** RBC:FFP:Platelets in equal amounts - prevents dilutional coagulopathy
- •**TXA:** 1g IV bolus, then 1g over 8h (CRASH-2 protocol - within 3h of injury)
- •**Lethal triad:** Hypothermia, Acidosis, Coagulopathy - monitor and correct
- •**Lab monitoring:** Hb, INR, fibrinogen, platelets every 30-60 min
Jehovah's Witness Management
- •**Discuss:** Individual beliefs vary - many accept EPO, TXA, cell salvage (continuous circuit)
- •**Document:** Signed refusal form, documented risks including death, witness to consent
- •**Optimize:** EPO 40,000 units weekly x 4 + IV iron 1000 mg. Goal Hb greater than 130 g/L preop
- •**Minimize:** TXA, cell salvage, meticulous hemostasis, hypotensive anesthesia, consider staging bilateral procedures
- •**Accept:** Lower Hb postop (60-70 g/L). Supplemental O2, early mobilization
Key Trials and Evidence
- •**CRASH-2 (2010):** TXA in trauma reduces mortality (16.0% to 14.5%) if given within 3h. After 8h, harmful.
- •**TRICC (1999):** Restrictive (Hb less than 70) vs liberal (less than 100) - restrictive safe, reduces transfusions
- •**FOCUS (2011):** Hip fracture patients - restrictive (Hb less than 80) safe even in elderly with comorbidities
- •**Cochrane TXA (2015):** 60 RCTs ortho - TXA reduces transfusion 30-50%, NO VTE increase
- •**NHMRC PBM Guidelines (2012):** Australian standard - optimize, minimize, manage transfusion appropriately
Australian Context
- •**NBA PBM Guidelines:** Module 2 Perioperative - screen anemia, TXA, cell salvage, restrictive transfusion
- •**PBS:** IV iron (FCM) listed with authority. EPO NOT listed for elective ortho (hospital/patient funded)
- •**Blood costs:** 1 unit RBC $500-800 AUD including administration, testing, monitoring
- •**Donor supply:** Voluntary donors, periodic shortages (esp O neg) - drives PBM approach