Local Anesthetics Quiz

Good Drugs, Bad Drugs & Anesthesia Part II

• Presented by Dr. Tonia Timperley Tauh MD FRCPC
• Contact information provided

Last Lecture Good Drugs Bad Drugs Part I

• Pain Management:
  • Non-opiate analgesia
  • Non-steroidal anti-inflammatory drugs (NSAIDs)
  • Acetaminophen
  • Methocarbamol
  • Opiates analgesia

Drug: Fentanyl/Morphine

• Class: Opiates
• Mechanism of Action (MOA): Calcium channel blocker
• Uses: Analgesia, additive anesthesia, sedation
• Side Effects: (List incomplete)

Side Effects of Hydrocodone

• Central Nervous System: Drowsiness, dizziness, lightheadedness, fuzzy thinking, anxiety, abnormally happy or sad mood
• Skin: Rash, itching
• Respiratory: Slowed or irregular breathing, chest tightness
• Throat: Dryness
• Gastrointestinal: Nausea, vomiting
• Urinary: Difficulty urinating
• Intestinal: Constipation

Illegal Drug Overdose Deaths in BC (Figure 1)

• Data presented for the years 1991-2017
• Shows a significant increase in overdose deaths over time
• Death rate per 100,000 population is presented

Predictors of Fatal and Nonfatal Opioid Overdose

• Increased Risk Factors
  • Higher opioid dose
  • Three or more prescribers
  • Four or more dispensing pharmacies
  • Prescription of fentanyl
  • Current substance abuse
  • Mental health diagnoses (depression, bipolar disorder)
  • Pancreatitis

Case #2

• 35-year-old female, 4 days post motor vehicle accident surgery
• Prescribed Hydromorphone (Dilaudid)
• Patient takes acetaminophen, naproxen, and hydromorphone, and brother suggests it is dangerous to mix these drugs
• Question: Is mixing these drugs dangerous?

Opiate Antagonist: Naloxone (Narcan)

• Mechanism of Action: Binds onto the opiate mu receptor with high affinity, reversing depressed respiration
• Use: Reverses opioid overdose
• Side effects: Reverses analgesia
• Mechanism of action: Reverses opioid overdose from its stronger affinity to opioid receptors

Drug: Naloxone

• Class: Opioid antagonist
• Mechanism of Action (MOA): Binds to the opioid mu receptor with high affinity, displacing opioids, rapidly reverses any molecules occupying the mu receptor
• Use: Reverses respiratory depression, treats opioid-induced pruritis
• Side Effects: Reverses analgesia

Objectives

• Local anesthetic
• Regional anesthesia
• Sedation anesthetic (Conscious Sedation)
• General anesthetic

Good Drugs or Bad Drugs?

• All good drugs have bad ways to use them
• All bad drugs have good ways to use them
• Use information about risks to stratify.

WebMD (Humor)

• A humorous take on the potential for exaggeration in medical information

Local Anesthetic

• Mechanism of action: Blocks the propagation of nerve action by blocking sodium channels
• Examples:
  • Cocaine
  • Lidocaine
  • Prilocaine
  • Bupivacaine

Regional Anesthesia

• Involves injecting local anesthetic to block a large area of the body, such as an arm or leg.
• This avoids the need for general anesthesia
• Used for surgical anesthesia, post-operative pain and labor analgesia

Mechanism of Action: Diagrams

• Diagrams illustrating the processes of pain transmission and the blocking effect of anesthetic

Local Anesthetic: Specifics

• Lidocaine – sodium channel blocker.
  • Prevents propagation of nerve action

Regional Anesthesia - Epidural vs Spinal

• Diagram comparing and contrasting epidural and spinal anesthesia.
  • Locations
  • Techniques used

Regional Anesthesia - Epidural

• A form of regional anesthesia
• Involves injection of local anesthetic and/or opiates into the epidural space
• Uses: Continuous analgesia for labor pain, post operative pain after abdominal or chest surgery

Regional Anesthesia - Types

• Spinal
• Epidural
• Peripheral Nerve blocks
• TAP block
• Digital ring block

Why Epidural?

• Pain control intra and post operative care
• Use less general anesthetic
• An infusion or patient-controlled analgesia
• Use less opiates systemically
• Less side effects like constipation sedation and respiratory depression

Question

• 46-year-old female for a tooth extraction.
• What is the mechanism of action of lidocaine?
• What are some local anesthetic toxicity signs and symptoms?

Drug: Lidocaine/Cocaine

• Class: Local anesthetic
• Mechanism of Action (MOA): Sodium channel blocker
• Uses: Local or regional anesthetic for procedures like dental work, surgery, labor, and pain management.
• Side Effects: Seizures, arrhythmia, and complete heart block

A 34-year-old Gorilla Health Check Up (Humour)

Common Questions Before Anesthesia

• Patient concerns about dying or having pain during anesthesia.
• Asking about procedures regarding alertness and possible allergies.
• Knowing the guidelines of whether food or drink is allowed.
• Desired level of anesthesia needed.

Light, Deep, General Sedation

• Table comparing light, deep, and general sedation levels based on responsiveness, airway, respiration, ventilation, and cardiovascular function
  • Responsiveness: Normal response to commands, purposeful response to pain, no response to pain
  • Airway: Unaffected, mildly collapsed, no intervention, breathing device needed
  • Respiration & Ventilation: Spontaneous breathing, slow deep breaths needing supplemental oxygen, inadequate breathing requiring mechanical ventilation or assisted breathing
  • Cardiovascular Function: Normal, bradycardia, hypotension, impaired function requiring pharmacological support

Sedation via Oral or IV

• Explain sedation may be via oral medication or intravenous (IV) medication

Benzodiazepines

• Mechanism of action: Benzodiazepine-receptor binding enhances the inhibitory effects of various neurotransmitters (e.g., GABA)
• Examples:
  • Oral: Ativan (lorazepam), oxazepam
  • IV: Midazolam
• Side effects: Respiratory depression at high doses

When You Go to Your Dentist, Endoscopy, Colonoscopy, etc

• Discuss anxiety and the benefit in having sedation during these procedures.

Propofol

• Mechanism of Action: Facilitation of inhibitory neurotransmission mediated by GABA
• Rapid Onset & Pleasant Dreams - pleasant experience is possible
• Side Effects: Burns on injection, hypotension, bradycardia

Risks of Dying Under Anesthesia

• Historical risks (e.g., 1940s 1:1000, 2010s 1:1.1 million per year)
• Factors like surgical technique, anesthetic techniques, monitoring and preoperative assessment

1987 - Saturation Probe & Present Day

• Show and compare older style and present day equipment for monitoring patients.

Cardiac Surgery Anesthesia

Anesthesia-Related Mortality

• Epidemiology of Anesthesia-related Mortality; United States (1999-2005) data.
• Rates presented; rates for males, females, hospital discharges and based on age groups.
• Transport Canada Fatal Collision data including rates for 2017.

Questions?

• Contact information provided for Dr. Tonia Timperley Tauh.
• Disclaimer related to the content provided.

Test your knowledge on the mechanisms, applications, and side effects of local anesthetics. This quiz covers various techniques including epidurals and peripheral nerve blocks, alongside the common local anesthetics used in clinical practice. Perfect for healthcare professionals and students in the medical field.