What are the implications of substance misuse for intravenous conscious sedation practice?

This summary is based on the article published in the British Dental Association: The implications of substance misuse for intravenous conscious sedation practice (February 2015)

J. Noone, E. Critchley, P. Cullingham, P. Coulthard, A. Saksena

Context

• Substance misuse is a major health concern, as the consequences for individuals are significant and may include multisystem organ damage.
• It is important for the dentist to know which patients are misusing substances as some pharmacological agents routinely used in dental practice may be contraindicated.
• The dentist should be aware of the range of clinical presentations that may arise from substance misuse and when suspected, a thorough drug history must be obtained.
• Patients may require special consideration and further investigations when planning elective procedures, particularly under intravenous conscious sedation.
• Therefore, management within a specialist centre and liaison with other health professionals may be indicated to ensure treatment is provided safely.

Purpose of the Article

1. Discuss some of the most frequently used recreational drugs, their effects and their relevance for the dental sedationist.
2. Discuss why it is important to know a patient’s history of substance abuse before administering local anesthesia or systemic analgesia, as it permits to predict adverse drug interactions and predict tolerance to certain agents.
3. Promote good clinical practice through recommendations for the provision of safe and effective conscious sedation in dentistry.

Key Messages

• Metabolic consequences of drug misuse are uncommon but increasing as substance misuse becomes more widespread. The range of associated medical problems is very wide although they most commonly occur with abuse of heroin, cocaine and ecstasy.
• The treating dentist must remember that drug addictions affect all gender, socioeconomic, and age groups.
• The dentist must discuss with the patient his or her history of drug abuse, in a non-condemnatory fashion, during the review of the patient’s medical history before treatment.
• Special investigations:
  • Examination of cardiovascular and respiratory systems.
  • Coagulation screen to provide an initial broad categorization of hemostatic problems which may result from alcohol abuse.
  • Platelet count to screen for thrombocytopenia caused by excessive cannabis, heroin, cocaine, ecstasy and MDMA use.
  • Liver function tests to screen for the presence of liver disease, affecting the production of vitamin K dependent clotting factors (II, VII, IX, X).
  • Glomerular filtration rate to assess for renal damage or failure.
  • Oxygen saturation to assess for lung complications including tuberculosis and various types of pneumonia.
  • Hep B and Hep C, HIV screen, tuberculin test to screen for various infectious diseases.
  • ECG to assess for potentially fatal cardiac arrhythmias.
• Potential complications:
  • Cardiovascular risks increased with local anesthetic with vasoconstrictor, such as lethal cardiac arrhythmias and cerebral hemorrhage. ^10–14
  • Increased bleeding tendency due to altered platelet function, liver disease and vitamin K deficiency.
  • Renal damage possibly caused or exacerbated by substance abuse. Renal insufficiency can lead to prolonged sedation due to the reduced clearance and accumulation of metabolites
  • Increased risk of receiving inadequate pain management which makes providing effective pain management complex. ¹⁵
• Precautions:
  • May advisable to use plain local anesthetic solutions to minimize risks of myocardial infarction, hypertension, lethal cardiac arrhythmias and cerebrovascular accidents in substance abusers. ^16–23
  • Prescribing paracetamol for postoperative pain should be limited to less than 2.5 g daily in dental patients with a history of drug and alcohol abuse with compromised hepatic function. ¹⁸
  • In patients with renal insufficiency, no specific adjustments for the dosage
  • In patients with renal insufficiency, the amount of vasoconstrictor should be minimized because of hypertension secondary to renal disease. ²²
  • It is suggested that dentists tell their heavy-using marijuana patients to cease its use for at least one week before dental treatment. ²⁵ It is sensible to suggest that plain local anesthetic solutions are used where possible.
  • Patients with addiction often complain of higher levels of pain than would be expected for a given procedure/situation. Liaising with a medical professional may be advisable to formulate a plan for postoperative analgesia that will be adequate and safe.

References

List of references (PDF)