Why do elderly patients with cardiovascular disease, osteoporosis, or fractures, taking diuretics and warfarin (anticoagulant), have a high risk of bone cement implantation syndrome?

Why Diuretics and Warfarin Increase BCIS Risk

Diuretic use is an independent predictor of severe bone cement implantation syndrome (BCIS) because these medications predispose patients to intravascular volume depletion, which critically impairs the cardiovascular system's ability to compensate for the sudden hemodynamic insult caused by cement insertion, fat embolism, and vasoactive mediator release during cemented arthroplasty. 1, 2

Evidence-Based Risk Factors

The 2015 AAGBI/BOA/BGS Safety Guideline explicitly identifies diuretic medication use as a key patient factor associated with increased risk of severe cardiovascular events during cemented hemiarthroplasty. 1 A large retrospective study of 1,016 patients confirmed that diuretic use is an independent predictor for severe BCIS, alongside warfarin use. 2

Why Diuretics Increase Risk

• Chronic volume depletion: Diuretics reduce intravascular volume through their mechanism of action, creating a baseline state of relative hypovolemia that leaves minimal cardiovascular reserve. 1
• Impaired compensatory mechanisms: When cement insertion triggers sudden hypotension (via fat/marrow emboli, vasoactive mediators, and increased pulmonary vascular resistance), volume-depleted patients cannot mount adequate compensatory responses. 1, 2
• Synergistic effect with surgical trauma: The combination of pre-existing volume depletion and the acute hemodynamic insult of cementation creates a "perfect storm" for cardiovascular collapse. 1

Why Warfarin Increases Risk

Warfarin use is also an independent predictor of severe BCIS, though the mechanism differs from diuretics. 2 While the evidence doesn't explicitly detail warfarin's mechanism, the most plausible explanations include:

• Increased bleeding risk: Anticoagulation may worsen intraoperative blood loss, compounding hypovolemia. 2
• Marker of comorbidity: Warfarin use indicates underlying cardiovascular disease (atrial fibrillation, thromboembolism history, valvular disease), which independently increases BCIS risk. 1
• Impaired hemostasis: Reduced clotting capacity may worsen the consequences of marrow/fat embolization. 2

Clinical Context and Magnitude of Risk

• BCIS occurs in approximately 20% of cemented hip fracture operations, with severe BCIS (Grades 2-3) occurring in 6.8% of cases. 1, 2
• Severe BCIS carries a 16-fold increase in mortality risk, with Grade 2 BCIS having 35% early mortality and Grade 3 having 88% early mortality. 2
• Other independent risk factors include: age >75 years, male sex, ASA Class III-IV, significant cardiopulmonary disease, COPD, and renal impairment. 1, 3, 2

Pathophysiology of BCIS

The syndrome results from a multimodal etiology involving: 1

• Fat, platelet, fibrin, and marrow emboli entering circulation during femoral canal instrumentation. 1
• Stimulated release of vasoactive mediators causing systemic vasodilation and pulmonary vasoconstriction. 1
• Increased pulmonary vascular resistance leading to right heart strain. 1, 4
• Acute hypoxia and hypotension from the combined effects. 1, 2

Critical Prevention Strategies for High-Risk Patients

For patients on diuretics or warfarin, aggressive preoperative optimization is mandatory:

Fluid Management

• Ensure adequate hydration before induction and throughout surgery—many patients are hypovolemic pre-operatively and require routine fluid therapy. 1, 5
• Avoid intravascular volume depletion at all costs during the procedure. 1
• Consider cardiac output-guided fluid administration to optimize volume status. 1, 5

Hemodynamic Monitoring

• Use invasive arterial blood pressure monitoring in high-risk patients (including those on diuretics/warfarin). 1
• Maintain systolic blood pressure within 20% of pre-induction values using vasopressors and/or fluids. 1, 6
• Have vasopressors immediately available (metaraminol/epinephrine) before cementation. 1, 6

Surgical Technique Modifications

• Thoroughly wash and dry the femoral canal using pressurized lavage to remove fat and marrow. 1, 6
• Use retrograde cement insertion with cement gun, distal suction catheter, and intramedullary plug. 1, 6
• Avoid excessive manual pressurization in high-risk patients. 1, 6
• Increase inspired oxygen to 100% at time of cementation. 1, 6

Communication Protocol

• Surgeon must verbally announce intent to instrument femoral canal. 1, 6
• Anesthesiologist must verbally confirm awareness of impending cementation. 1, 6
• Pre-list briefing and WHO Safe Surgery checklist "time-out" must identify BCIS risk. 1, 6

Common Pitfalls to Avoid

• Failing to recognize diuretic/warfarin use as high-risk markers: These medications must trigger heightened vigilance and aggressive prevention strategies. 2
• Inadequate preoperative fluid resuscitation: Assuming baseline euvolemia in diuretic users is dangerous. 1
• Delayed recognition of hemodynamic changes: A sudden drop in systolic pressure or end-tidal CO₂ heralds impending collapse. 1
• Insufficient preparation: Vasopressors must be drawn up and ready before cementation begins. 1