LA choice and medical history Flashcards
List the 9 common medical conditions that need to be considered for LA (hint, 3 aren’t medical conditions…)
Hypertension
Coronary artery disease
Asthma
Anti-depressants
Pregnancy
Hyperthyroidism
Pheochromocytoma
Allergy
Cocaine
Describe the issue with hypertension and LA
- Adrenaline will increase BP (increased peripheral resistance)
- Stress will increase BP (white-coat syndrome)
Contraindications with medications:
• Theoretical risk regarding non-selective β-blockers
• An injection of LA with vasoconstrictor may produce vasoconstriction
• This could result in a dangerous increase in blood pressure
Describe the management of hypertension and LA
- Check BP prior to treatment
- If >160/100 rest patient, re-take 5 mins. Monitor patient during procedure
- Use LA with vasoconstrictor: increased duration and depth, reduces systemic toxicity BUT with careful aspiration, slow injection, minimal dose
- If BP is too high, wait until physician can get their blood pressure under control
- Refuse treatment if BP > 180/110
Describe the issue with coronary heart disease and LA
- Adrenaline increases rate and force of myocardial contraction —> increased oxygen demand
- Pain/stress also has the same effect
Risk of angina/MI
• People with stable angina: no risk
• People with unstable angina, recent bypass surgery or myocardial infarction: POSTPONE
Describe the management of coronary heart disease and LA
- Short morning appointments
- Stress reduction protocol
- Effective, low dose LA
- With vasoconstrictor
- Slow injection, aspiration
Describe the issue with asthma and LA
- Adrenaline is bronchodilator
- Stress of dental visit / injection can trigger asthma attack
- Sensitivity to bisulfites (preservative) is possible —> hypersensitivity/allergic response
Describe the management of asthma and LA
- Check history: frequency / severity of ‘attacks’
* Make sure patient has adhered to medication regime and has bronchodilator with them, prior to treatment
Describe the issue with antidepressants and LA
- Antidepressants increase the amount of serotonin and/or norepinephrine at the synapse
- Does LA (containing vasoconstrictor) administration lead to an increased level of circulating catecholamines?
- Exogenous metabolism: hepatic metabolism
Describe the management of LA antidepressants
- Tri-cyclic antidepressants: use only minimal amounts of LA
- Selective-serotonin reuptake inhibitors: no issue because this only blocks serotonin uptake
- Mono-amine oxidase inhibitors (MAOIs): possible that pain and/or anxiety from the injection might activate the sympathetic nervous system with exaggerated effects from MAOIs on blood pressure and heart rate
Describe the management of pregnancy antidepressants and LA (which types of LA can you use?)
Contraindications
• Articaine classification B3
Indications
• Prilocaine with felypressin
• Lignocaine, mepivacaine
All grade A
Describe the issue with hyperthyroidism and LA
- Excessive thyroid hormones can be accompanied with hypertension and cardiac abnormalities
- Well-managed patients present no problems and may be given normal concentrations of vasoconstrictors
Describe the management of hyperthyroidism and LA
The use of vasoconstrictors in local anaesthetics should be avoided, or at least minimised to one to two cartridges for the poorly controlled hyperthyroid patient
Describe the issue with pheochromocytoma and LA
- Tumour of the adrenal medulla or of the sympathetic paravertebral ganglia
- Secretion of excessive adrenaline = hypertension
Describe the management of pheochromocytoma and LA
- Due to the risk of potentiating cardiovascular problems, the use of vasoconstrictor-containing local anaesthetics is contraindicated
- Do not treat until it is medically corrected
Describe the issue with LA and allergies
- Articaine has no immunogenic components = no allergies
- Sodium metabisulfite, allergy to sulphites
- This helps to prevent the decomposition of adrenaline
- Thus allergic patients may experience cross-reactions with local anaesthetic solutions containing adrenaline
