Opiod Toxicity Flashcards Preview

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Flashcards in Opiod Toxicity Deck (21)
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1
Q

What are features of opiate toxicity?

A
  • Decreased GCS
  • Respiratory depression
  • Constipation/decreased bowel sounds
  • Bradycardia/hypotension
  • Hypothermia
  • Seizures
  • Bilateral miosis
  • Euphoria/dysphoria
2
Q

Which of the 3 main opioid receptors is most implicated in the development of respiratory depression in overdose?

A

u-receptor and δ-receptor agonism

3
Q

What is not a reliable sign of opiate intoxication?

A

Pinpoint pupils - variable presentation in opioid overdose

4
Q

How does renal dyfunction influence opioid toxicity?

A

Interferes with excretion, therefore certain opioids accumulate more easily

5
Q

Which opioids/opiates are more likely to accumulate in renal dyfunction?

A
  • Morphine
  • Diamorphine
  • Codeine
  • Pethidine
6
Q

Which opiates are better to use in renal dyfunction?

A
  • Oxycodone
  • Fentanyl
  • Alfentanyl
7
Q

Why can some opioids cause itch?

A

Due to histamine release - particularly with codeine

8
Q

How would you manage someone with suspected opioid toxicity?

A
  1. Airway maneuvre - head tilt chin lift
  2. Ventilate
  3. Consider need for ABG
  4. IV/IM naloxone
  5. Look for sources of exogenous opioids
  6. Management of complications
    • Benzodiazepines - seizures/agitation/delerium
    • Chlorphenamine - pruritis
9
Q

What clinical circumstances do you need to take into account when considering naloxone regime to give?

A

Whether the patient is acute opioid intoxication or whether they are on opioids for pain relief post-op/palliatively - determines the rate of titration of naloxone

10
Q

How would you administer naloxone when treating opioid toxicity int the acutre rescuscitative phase?

A
  1. Give 400 mcg initially
  2. If no response after 60 seconds, give 800 mcg
  3. If still no response after 60 seconds, give further 800 mcg
  4. If still no response after 2mg overall, give further 2 mg (large doses may be required for severely intoxicated individuals
  5. Aim for reversal of respiratory depression, not full reversal of unconsciousness
11
Q

What would failure to respond to rescuscitative naloxone suggest?

A

Another CNS depressant or brain damage is present

12
Q

What is important to remember about nalxone in terms of duration of action relative to that of opiates?

A

Shorter duration of action (1-1.5 hours), therefore narcosis may recur and multiple doses may be required

13
Q

What is the duration of action of IV naloxone vs IM naloxone?

A

IV - 1-1.5 hours

IM - 3 hours

14
Q

How long does it take naloxone to act IV vs IM

A
  • IV - 1-2 minutes
  • IM - 3-5 minutes
15
Q

What are features of opioid withdrawal?

A
  • Flu-like symptoms: rhinorrhea, chills, piloerection, myalgia, arthralgia, leg cramps
  • GI complaints: nausea, vomiting, abdominal pain, diarrhea, hyperactive bowel sounds
  • Features of sympathetic hyperactivity: mydriasis, tachycardia, hypertension, hyperreflexia
  • Features of CNS stimulation: insomnia, yawning, irritability, anxiety, agitation, aggression
16
Q

When would you consider giving a naloxone infusion?

A

If repeated doses are required

17
Q

How would you start a naloxone infusion?

A

Aim for 60% of dose required to reverse resp. depression e.g. if 800 mcg required -> 500mcg/hour. Once started, titrate to effect

18
Q

If someone who has iatrogenic opioid withdrawal (e.g following naloxone injection for iatrogenic opioid overdose) and they have opioid dependency, what is the risk that can occur?

A

Acute severe opioid withdrawal

19
Q

What should you not do if iatrogenic withdrawal is induced and the patient is in pain/suffering severe opioid withdrawal symptoms?

A

Give more opiates to try to reverse the effect - naloxone will clear from the system quickly, meaning that the overall opiate load will still be high - re-establishment of narcosis, which ccould be made worse by further opioid adminstration

20
Q

In those who are naturally withdrawing from opioids, what approaches would you take when managing them?

A
  • Direct withdrawal antagonism - Methodone/buprenorphine
  • Symptom management
    • N+V - anti-emetic
    • Diarrhoea - loperamide
    • Anxiety/dyphoria/muscle cramps - diazepam 1-10 mg IV PO/IM
21
Q

Where should naloxone infusion be administered in terms of hsopital setting?

A

HDU setting - MHDU/SHDU