Exam 2 (Acute Pain & OFA) Flashcards
- Which pain feels sharp & stabbing?
Visceral/Parietal pain
- What are the renal consequences of pain?
Oliguria & retention
- What are the coagulation consequences of pain?
Increased risk of thromboemboli
Who said pain is directly related to the amount of tissue injury & what theory is it?
Rene Descartes Specificity Theory
- Who came up with the Intensity Theory & what is it?
- Plato
- Pain is an emotional experience rather than sensory
- Who came up with the Gate Control Theory?
Ronald Melzack & Patrick Wall
- What are the inflammatory mediators in trauma?
- Bradykinin,
- prostaglandins &
- serotonin
- 2nd order neurons start & end where?
- Start at dorsal horn &
- end at thalamus
- Which fiber is larger, C-fibers or A-delta?
A-delta
- What is modulation?
Pain transmission alters afferent neural transmission.
- What is primary hyperalgesia?
Augmented sensitivity to painful response
- What is secondary hyperalgesia?
Increased excitability of neurons in the CNS due to glutamate activation of NMDA receptors
- Which anesthesia med can cause hyperalgesia?
Remifentanil
- What happens to the GI system with age?
- Decreased gastric acid secretion.
- Elevated gastric pH.
- Reduced motility & GI blood flow
What type of drugs can be erratic with elderly patients?
- Water soluble drugs &
- protein binding drugs
- What are the notable adverse effects of non-opioid analgesics?
- Gastric irritation
- Bleeding
- Renal toxicity
- Which class of drugs have a ceiling effect?
Non-opioid analgesics
- What are the Mu receptor responses to opioids?
- Analgesia,
- respiratory depression
- Euphoria
- Reduce GI motility
- What are the Kappa receptor responses to opioids?
- Analgesia
- Respiratory depression
- dysphoria,
- delusion/delirium
- Miosis
- What are the Delta receptor responses to opioids?
Analgesia
- Which opioid receptor causes dysphoria?
Kappa
- Which drug has better absorption, codeine or morphine?
Codeine
- Which patient should not receive codeine & why?
Children <12yrs lack an enzyme causing side effects w/o analgesia
- What is the adult dose for codeine?
15-60mg q4hr
- Which receptors does tramadol activate?
- Primarily Mu,
- Kappa &
- Delta
- What does Tramadol’s (-) enantiomer do?
- It inhibits NE reuptake &
- stimulates alpha-2 receptors
- How effective is Tramadol’s metabolite?
2-4 times as strong
- What is the T½ of tramadol?
6hrs + 7hrs for metabolite
- What is the onset for Tramadol?
1-2hrs PO
- Which Pts should not receive tramadol?
Seizure patients
- What is a big side effect with tramadol?
Nausea & vomiting
- Which receptors are primarily affected by morphine?
Mu-1 & Mu-2
- Which morphine metabolite causes issues, & what kind?
- Morphine-3-glucuronide
- causes neurotoxicity & hyperalgesia
- How does morphine affect the CNS?
Poorly d/t poor lipid solubility & high protein binding
- Who possibly needs reduced doses of morphine?
Women
- Oxycodone is a derivative of?
Thebaine
- What receptors does oxycodone work on?
Mu & Kappa
- How long can methadone’s effects last?
Up to 36hrs
- What receptors does methadone affect?
- Methadone is a:
- Mu receptor agonists
- & an antagonist/inhibitor for:
- NMDA antagonist,
- serotonin reuptake inhibitor,
- MAOI inhibitor,
- What can increase the effects of methadone?
- Grapefruit juice,
- carbamazepine,
- antiretroviral agents
- How is methadone affect by the hepatic & renal systems?
Not very much
- What is a downside for patients starting methadone?
- It takes ~ 10 days to get to steady state &
- half-life varies greatly
- What are the PO doses for methadone?
2.5 – 10mg
- What is IV dose for methadone?
One time 10mg
- What meds cause increased methadone effects?
- Ciprofloxacin,
- diazepam,
- ethanol
- What meds are avoided with methadone?
MAOI’s
- What are some possible cardiac effects of methadone?
- Prolonged QT
- Bradycardia
- Torsades
- What meds can decrease methadone effects?
-Phenobarbital,
- phenytoin,
- rifampin,
- amprenavir
- What surgery equipment could interfere with medication patches?
Surgeries including cautery
- How do antidepressants help with reducing pain?
They increase transmission in the spinal cord to reduce pain signals
- What is the half-life for transmucosal fentanyl?
2 – 12hrs
- What is the average half-life for most PO opioids & which is the outlier?
- 2 – 4hrs
- Propoxyphene lasts 12 – 16hrs
- What is the parenteral dose of Codeine?
130mg
- What is the fentanyl metabolite & how long does it stay in the system?
- Norfentanyl &
- in urine for up to 72hrs
- Why is fentanyl elimination prolonged?
- The lungs serve as an inactive reservoir &
- They absorb ~ 75% during first-pass effect
- What can be used when a Pt is refractory to fentanyl?
Hydromorphone
- What are possible side effects of dilaudid’s metabolite?
- Allodynia,
- myoclonus &
- seizures
- What is the post-op pain dose for dilaudid?
0.2mg q 3-5mins
- How much stronger is hydrocodone compared to codeine?
6 – 8 times
- What are the interactions of hydrocodone?
- CYP inhibitors/inducers
- Hypotension w/ barbs
- IV magnesium or CCB may increase opioid effect
- At what receptors does buprenorphine work?
- Partial Mu receptor agonist.
- Kappa antagonist.
- Weak Delta agonist
- Where is buprenorphine eliminated?
In the liver
- What is the danger with buprenorphine’s metabolite?
Respiratory depression is 10 fold
- What is the dose & half-life of buprenorphine?
- 0.3mg IM &
- 20 – 73hrs
- What is the best route of administration for buprenorphine & why?
- Subliqual or transdermal
- d/t high first-pass metabolism
- Which drug has higher withdrawal S/S, morphine or buprenorphine?
Morphine
- What is the problem with treating a buprenorphine OD?
Delayed naloxone onset d/t it being an agonist & antagonist
- What S/S has been observed with buprenorphine?
Pulmonary edema
Which opioid receptors can cause pruritus & physical dependence?
Mu & Delta
What is an absolute contraindication to OFA?
Allergy to any adjuvant drugs
What is the OFA dose for ketamine?
< 0.5mg/kg
How does Esmolol help in OFA?
It decreases the HR, which decreased cardiac output leading to decreased hepatic blood flow, slowing metabolism of other drugs.
How does magnesium help in OFA?
Acts as non-competitive antagonist of NMDA glutamate receptors → decreased calcium & sodium entry into the cells & prevents potassium efflux.
What dexamethasone dose is appropriate as an anti-inflammatory?
10mg
What NMBd is most appropriate as a maintenance drug in elderly?
Cisatracurium (Nimbex)
What is an appropriate OFA ketamine dose?
0.3 mg/kg
How many opioid doses can cause tolerance?
1 dose
