1.2 Haematology, Hepatic & Renal Disease & Bleeding Disorders

1.2 Haematology, Hepatic & Renal Disease & Bleeding Disorders

Management of patients with disorders of hemostasis, liver insufficiency, or end-stage renal disease demands thorough pre-operative assessment and adherence to evidence-based UK guidance. Dental practitioners sitting the LDS Part 1 must understand bleeding risk stratification, drug clearance pathways, local hemostatic agents, and systemic precautions.

---

1. Bleeding Disorders & Anticoagulant Management in Dentistry

Physiological Hemostasis Overview

Hemostasis consists of two coupled pathways:

1. Primary Hemostasis: Vascular constriction and platelet adhesion, activation, and aggregation forming a temporary soft platelet plug. Evaluated by platelet count (normal: 150–400 × 10⁹/L).
2. Secondary Hemostasis: Activation of the coagulation cascade (intrinsic, extrinsic, and common pathways) generating a cross-linked fibrin mesh. Evaluated by Prothrombin Time (PT), Activated Partial Thromboplastin Time (APTT), and International Normalised Ratio (INR).

Congenital Bleeding Disorders

Haemophilia A and Haemophilia B

• Haemophilia A: X-linked recessive deficiency of Factor VIII.
• Haemophilia B (Christmas Disease): X-linked recessive deficiency of Factor IX.

Both conditions prolong the APTT while PT and platelet counts remain normal.

Mandatory Clinical Protocol: Never perform nerve blocks (e.g., inferior alveolar nerve block) or surgical extractions in patients with moderate or severe haemophilia without prior consultation with their Haemophilia Comprehensive Care Centre. Pre-operative administration of intravenous Factor VIII/IX concentrates or desmopressin (DDAVP) is mandatory to achieve target factor levels (> 50–80% normal activity).

von Willebrand Disease (vWD)

vWD is the most common inherited bleeding disorder (autosomal dominant). It involves quantitative or qualitative defects in von Willebrand factor (vWF), which mediates platelet adhesion to subendothelial collagen and stabilizes circulating Factor VIII. Managed via desmopressin (DDAVP), vWF factor concentrates, and topical 5% tranexamic acid mouthwash (10 mL used QDS for 7 days).

Acquired Bleeding & Anticoagulant / Antiplatelet Therapy (SDCEP Guidance)

Warfarin (Vitamin K Antagonist)

Warfarin inhibits vitamin K epoxide reductase, blocking gamma-carboxylation of clotting Factors II, VII, IX, and X.

• INR Monitoring: Check INR within 24 hours (up to 72 hours if stable) prior to invasive dental procedures.
• INR Cutoff: Minor oral surgery (extractions of up to 3 teeth, periodontal surgery) can safely proceed if the INR is ≤ 4.0.
• Critical Directive: DO NOT stop warfarin. Interruption of warfarin creates a high risk of life-threatening thromboembolism (stroke, artificial valve thrombosis) that far outweighs the risk of local dental bleeding.

Direct Oral Anticoagulants (DOACs)

DOACs include direct Factor Xa inhibitors (Apixaban, Rivaroxaban, Edoxaban) and direct thrombin (Factor IIa) inhibitors (Dabigatran).

Antiplatelet Therapy (Aspirin, Clopidogrel, Ticagrelor)

• Single Antiplatelet Monotherapy (e.g. Aspirin 75 mg OD or Clopidogrel 75 mg OD).
• Dual Antiplatelet Therapy (DAPT) (e.g. Aspirin + Clopidogrel following drug-eluting coronary stent placement).
• SDCEP Directive: Never stop single or dual antiplatelet therapy for dental extractions. Local bleeding is readily managed using surgical hemostatic techniques.

Local Hemostatic Measures

For all patients with bleeding tendencies or anticoagulation:

1. Pack socket with oxidized regenerated cellulose (Surgicel) or gelatin sponge.
2. Apply cross-mattress resorbable sutures (3-0 or 4-0 Vicryl Rapide).
3. Apply direct pressure using gauze soaked in 5% tranexamic acid for 20 minutes.
4. Advise patient to avoid warm liquids, alcohol, spitting, and strenuous exercise for 24 hours.

---

2. Haematological Disorders: Anemias & Malignancies

Anemias

Iron Deficiency Anemia

Microcytic, hypochromic anemia caused by chronic blood loss or inadequate dietary iron intake.

• Oral Manifestations: Smooth erythematous atrophic glossitis (depapillation of tongue), angular cheilitis, oral mucosal pallor, burning mouth sensation (glossodynia).

Pernicious Anemia (Vitamin B12 Deficiency)

Macrocytic, megaloblastic anemia resulting from autoimmune destruction of gastric parietal cells and loss of intrinsic factor. Features include Hunter’s glossitis (painful, beefy red tongue), recurrent aphthous stomatitis, peripheral neuropathy, and altered taste sensation.

Sickle Cell Disease

Autosomal recessive point mutation in the beta-globin gene substituting valine for glutamic acid (HbS). Under hypoxic conditions, HbS polymerizes, distorting erythrocytes into rigid sickle shapes causing vaso-occlusion, tissue infarction, and severe pain crises.

• Dental Management: Maintain high atmospheric oxygenation; treat active infections aggressively; use local anaesthetics with 1:80,000 epinephrine safely, but avoid Prilocaine with Felypressin if cyanosis or hypoxia risk is present. Intravenous sedation and general anaesthesia must be conducted in a hospital setting.

Leukaemias & Agranulocytosis

Malignant proliferation of leucocytes in bone marrow leads to pancytopenia (anemia, neutropenia, thrombocytopenia).

• Oral Signs: Spontaneous gingival haemorrhage, generalized firm gingival enlargement (leukaemic cell infiltration, particularly in Acute Myeloid Leukaemia - AML), deep painful necrotic oral ulcers, petechiae, and opportunistic infections (Candida, Herpes Simplex).

---

3. Hepatic Disease & Dental Considerations

Pathophysiology & Liver Function Tests (LFTs)

The liver synthesizes all coagulation factors (except vWF and Factor VIII), processes bilirubin, and metabolizes amide local anaesthetics and systemic analgesics.

• ALT & AST: Markers of acute hepatocellular damage.
• ALP & Bilirubin: Markers of cholestasis and biliary obstruction (jaundice).
• Prothrombin Time (PT/INR) & Albumin: Direct indicators of hepatic synthetic capacity.

Pharmacological & Surgical Modifications

Local Anaesthetics

Amide local anaesthetics (Lidocaine, Articaine) undergo hepatic biotransformation via cytochrome P450 enzymes. In severe liver cirrhosis or end-stage hepatic failure, hepatic clearance is significantly reduced. Limit total lidocaine dosage to < 3 cartridges per visit.

Analgesic Contraindications

• Paracetamol: Safe at reduced doses (maximum 2 g / 24 hours) in patients with chronic liver disease, provided active alcohol abuse is absent.
• NSAIDs: Strictly contraindicated in chronic liver failure due to severe risk of precipitating acute upper gastrointestinal variceal bleeding and hepatorenal syndrome.
• Metronidazole & Erythromycin: Require 50% dose reduction due to impaired hepatic clearance.

Cross-Infection Control

Patients with chronic liver disease carry a higher prevalence of blood-borne viruses (Hepatitis B, Hepatitis C). Standard universal precautions, single-use disposable instruments where appropriate, and safe needle-recap devices are mandatory.

---

4. Renal Disease & Dental Management

Chronic Kidney Disease (CKD) & End-Stage Renal Disease (ESRD)

CKD is categorized by Estimated Glomerular Filtration Rate (eGFR):

• Stage 1: eGFR > 90 mL/min/1.73m² (Normal with kidney damage)
• Stage 3: eGFR 30–59 mL/min/1.73m² (Moderate impairment)
• Stage 5 (ESRD): eGFR < 15 mL/min/1.73m² (Renal failure requiring dialysis or transplant)

Oral & Radiographic Manifestations

• Uremic Stomatitis: Painful mucosal ulcerations and white pseudomembranes resulting from elevated salivary urea converted into corrosive ammonia by bacterial urease.
• Metallic Taste (Dysgeusia) & Uremic Foetor: Ammonia odor on breath.
• Renal Osteodystrophy: Secondary hyperparathyroidism leads to bone resorption, ground-glass trabecular appearance on intraoral radiographs, and loss of lamina dura surrounding tooth roots.

Dental Management Protocol for Dialysis Patients

Renal Dialysis Patient Requires Extraction
  ├── Check eGFR & Platelet Count
  ├── Avoid NSAIDs (Use Paracetamol 500mg - 1g)
  ├── Schedule Surgery on DAY AFTER Dialysis (Heparin cleared / Stable volume)
  └── DO NOT use arm with AV Fistula for BP cuff or IV access

1. Nephrotoxic Drug Avoidance: NSAIDs (ibuprofen, diclofenac, naproxen) ARE STRICTLY CONTRAINDICATED in CKD Stage 3–5. NSAIDs block renal prostaglandin synthesis, reducing renal perfusion and precipitating acute kidney injury (AKI).
2. Antibiotic Adjustments: Reduce dosage or extend dosing intervals for renal-cleared antibiotics like Amoxicillin in Stage 4–5 CKD.
3. Haemodialysis Timing: Perform invasive dental surgery on the day following haemodialysis. On the day of dialysis, systemic heparin is administered (high bleeding risk), and the patient experiences cardiovascular fatigue. By day 2, heparin has cleared and fluid/electrolyte balance is optimal.
4. Arteriovenous (AV) Fistula Protection: Never take blood pressure or gain intravenous access on the arm containing an active AV fistula, as compression can induce permanent shunt thrombosis.