1.1 Cardiovascular, Respiratory & Endocrine Disorders in Dental Practice

1.1 Cardiovascular, Respiratory & Endocrine Disorders in Dental Practice

Systemic medical conditions significantly influence dental treatment planning, pharmacological selection, and risk management. Dental practitioners preparing for the LDS Part 1 (Royal College of Surgeons of England) must master UK clinical standards, including guidelines from the National Institute for Health and Care Excellence (NICE), the Scottish Dental Clinical Effectiveness Programme (SDCEP), and the British National Formulary (BNF).

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1. Cardiovascular Disease in Dental Practice

Hypertension & Dental Risk Assessment

Hypertension is defined according to NICE guidelines based on clinic and ambulatory blood pressure (BP) monitoring thresholds:

• Stage 1 Hypertension: Clinic BP ≥ 140/90 mmHg (ABPM/HBPM average ≥ 135/85 mmHg).
• Stage 2 Hypertension: Clinic BP ≥ 160/100 mmHg (ABPM/HBPM average ≥ 150/95 mmHg).
• Stage 3 (Severe) Hypertension: Clinic BP ≥ 180 mmHg systolic or ≥ 120 mmHg diastolic.

In dental surgery, pain and anxiety induce endogenous catecholamine release (epinephrine and norepinephrine), causing transient spikes in blood pressure.

Local Anaesthetics and Epinephrine Safety: Lidocaine 2% with 1:80,000 epinephrine remains the gold standard local anaesthetic in UK dental practice. Epinephrine acts as a vasoconstrictor via alpha-1 adrenergic receptors, prolonging anaesthesia duration and reducing systemic absorption. However, in patients with severe, poorly controlled hypertension, significant cardiac arrhythmias, or unstable angina, epinephrine dosage should be limited to 2–3 cartridges (4.4–6.6 mL) per appointment, or an adrenaline-free formulation used—such as Prilocaine 3% with Felypressin (0.03 IU/mL) or Mepivacaine 3% plain.

Ischaemic Heart Disease (IHD) & Infective Endocarditis (IE)

Angina Pectoris & Myocardial Infarction (MI)

Patients with stable angina can undergo routine dental care provided appointments are short, stress-free, and scheduled for mid-morning. The patient's Glyceryl Trinitrate (GTN) spray must be placed on the dental bracket table prior to starting any procedure. Following an acute Myocardial Infarction (MI) or coronary artery bypass graft (CABG), elective dental care must be deferred for at least 6 months (or until cardiac stability is established by the cardiologist) due to high risk of re-infarction, fatal dysrhythmias, or acute heart failure.

Infective Endocarditis (IE) Prophylaxis (NICE CG64)

NICE Guideline CG64 (Prophylaxis against infective endocarditis) fundamentally changed UK dental practice by stating that routine antibiotic prophylaxis is NOT recommended for dental procedures in patients at risk of IE (including those with valve replacements, structural congenital heart disease, or previous IE).

Key pillars of current UK guidance:

1. Routine antibiotic prophylaxis before invasive dental procedures (extractions, periodontal scaling) is not offered.
2. Dentists must emphasize immaculate oral hygiene, regular dental checks, and prompt elimination of dental foci of infection to reduce chronic low-grade bacteremia.
3. Any acute dental infection in high-risk cardiac patients must be managed aggressively with prompt drainage, non-surgical debridement, or targeted systemic antibiotics.

Cardiac Pacemakers & Implantable Cardioverter-Defibrillators (ICDs)

Modern cardiac pacemakers and ICDs are encapsulated and bipolar, making them highly resistant to electromagnetic interference (EMI). Devices such as dental handpieces, curing lights, and diagnostic radiographs pose zero risk. Modern ultrasonic scalers and apex locators are safe with modern bipolar pacemakers; however, as a precautionary principle, ultrasonic handpieces and electrosurgery units should be kept at least 15 cm away from the generator pack in patients with older or unshielded cardiac pacemakers.

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2. Respiratory Disease in Dental Practice

Asthma

Asthma is characterized by chronic airway inflammation, bronchial hyper-responsiveness, and reversible bronchospasm.

Triggers in the Dental Environment

Common precipitating factors include dental anxiety, cold air, dental materials containing colophony (in fluoride varnishes), methyl methacrylate monomers, and specific systemic medications.

Aspirin-Exacerbated Respiratory Disease (AERD)

Approximately 10–20% of adult asthmatic patients exhibit sensitivity to aspirin and non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen, naproxen, and diclofenac. Inhibition of cyclooxygenase-1 (COX-1) shifts arachidonic acid breakdown toward the lipoxygenase pathway, resulting in excessive cysteinyl leukotriene production and severe bronchospasm.

Clinical Rule: Paracetamol (1 g QDS) is the safest first-line analgesic for asthmatic dental patients. Avoid NSAIDs in patients with severe asthma or a history of NSAID-induced wheezing.

Perioperative Management

• Patients must bring their short-acting beta-2 agonist rescue inhaler (Salbutamol 100 micrograms/puff) to every appointment.
• Prophylactic administration of 2 puffs of salbutamol before aerosol-generating or stressful procedures is recommended in severe asthmatics.
• Elective treatment should be rescheduled if the patient displays active wheezing or an upper respiratory tract infection.

Chronic Obstructive Pulmonary Disease (COPD)

COPD encompasses chronic bronchitis and emphysema, characterized by persistent, non-reversible airflow limitation.

Dental Modifications

1. Chair Positioning: Patients with severe COPD cannot tolerate a fully supine position due to orthopnoea and diaphragmatic compression. Treat patients in a semi-recumbent or upright chair position.
2. Oxygen Therapy Caution: Patients with end-stage COPD may rely on a hypoxic drive for respiratory regulation. Supplying high-concentration oxygen over prolonged periods can abolish hypoxic respiratory drive, inducing severe hypercapnia and respiratory acidosis. Target SpO2 in COPD is 88–92% (compared to standard 94–98%).
3. Sedation Contraindications: Intravenous sedation with Midazolam is contraindicated in moderate-to-severe COPD due to the high risk of central respiratory depression.

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3. Endocrine Disorders in Dental Practice

Diabetes Mellitus

Diabetes mellitus involves absolute (Type 1) or relative (Type 2) insulin deficiency, leading to chronic hyperglycaemia and systemic microvascular/macrovascular complications.

Oral Manifestations & Periodontal Inter-relationship

Diabetes and periodontitis exhibit a bidirectional relationship. Hyperglycaemia impairs neutrophil chemotaxis, phagocytosis, and collagen synthesis while elevating pro-inflammatory cytokines (TNF-alpha, IL-1beta) in the periodontium. Conversely, effective periodontal treatment reduces HbA1c by approximately 0.4% (4 mmol/mol), equivalent to adding a second oral hypoglycaemic drug.

Glycaemic Monitoring Parameters

• Target HbA1c for tight glycaemic control: < 48 mmol/mol (6.5%).
• Suboptimal control: 48–68 mmol/mol (6.5–8.4%).
• Poor control / High surgical risk: > 69 mmol/mol (≥ 8.5%).
• Normal fasting capillary blood glucose: 4.0–7.0 mmol/L.

Hypoglycaemia Management ("Four is the Floor")

Hypoglycaemia occurs when blood glucose falls below 4.0 mmol/L. Symptoms include neurogenic adrenergic activation (sweating, tremor, tachycardia, hunger, anxiety) progressing to neuroglycopenia (confusion, slurred speech, hostility, seizures, loss of consciousness).

Patient displays confusion/sweating → Measure Blood Glucose
  ├── Blood Glucose < 4.0 mmol/L (Conscious) → 15-20g Oral Glucose (200mL juice / Glucagel)
  └── Unconscious / Unable to swallow → Call 999 + Administer 1mg Glucagon IM

Dental Appointment Planning

Schedule diabetic appointments in the early morning, ensuring the patient has consumed their normal breakfast and taken their regular insulin or oral hypoglycaemic medication (e.g. metformin, gliclazide).

Adrenal Insufficiency & Corticosteroid Supplementation

Adrenal insufficiency may be primary (Addison’s disease) or secondary to prolonged exogenous corticosteroid therapy for autoimmune conditions (e.g., rheumatoid arthritis, lichen planus, asthma).

Risk of Addisonian Crisis

Severe physiological stress (e.g., surgical extractions, acute pain, infection) in patients with suppressed hypothalamic-pituitary-adrenal (HPA) axis can precipitate an Addisonian crisis—manifesting as acute severe hypotension, hypovolaemic shock, vomiting, hyperkalaemia, and vascular collapse.

SDCEP & BNF Guidelines for Steroid Supplementation

Patients receiving exogenous steroids (equivalent to > 7.5 mg prednisolone daily for > 3 weeks within the preceding 2 years) must be evaluated:

• Minor Dental Procedures under LA (restorations, hygiene, simple single extraction): No extra steroid cover required. Ensure effective local anaesthesia to prevent pain-induced stress.
• Major Oral Surgery / General Anaesthesia / High Anxiety: Double the patient's daily oral prednisolone dose on the morning of surgery, OR administer 100 mg hydrocortisone sodium succinate IV/IM 30 minutes prior to procedure.