Flashcards in Exam #6 Deck (47)
What general anesthesia is administered by an IV?
Milky white EMULSION
Not just for surgery, may be for other sedation such as in ICU on ventilator.
What is the mechanism of action for propofol (Diprivan)?
NMDA receptor agonist. Not sure how it works, theory of it activating GABA receptors in the brain.
What is the onset time and time it takes for propofol (Diprivan) to wear off?
Rapid onset. Almost instantaneous.
Waking up: about 10 minutes after cessation. Very fast.
Adverse effects of propofol (Diprivan)?
- Respiratory depression
- Propofol infusion syndrome
- CNS depressant, duh!
What about propofol (Diprivan) do you need to be concerned with regarding allergies?
Anyone allergic to soy or eggs. Propofol contains soy bean oil as well as egg products.
If patient's history unknown, will have to keep an eye on possible reaction.
What is Propofol Infusion Syndrome?
Occurs if on too long... resulting in:
- Metabolic acidosis (blood pH below 7.35)
- Cardiac failure
- Renal failure
Which general anesthetic is a volatile liquid?
Comes in liquid form then gets aerosolized into a gas for inhalation.
Used to really knock a person out for a surgery.
What is isoflurane (Forane)'s mechanism of action?
GABA receptor agonist and Glutamate receptor inhibitor.
Glutimate wakes our brain, so this works to inhibit glutimate to keep our brain "asleep".
What is the onset of action for isoflurane (Forane)?
Onset: 7-10 minutes
Wake up: within about an hour after cessation.
So, not used for short procedures!
What are the adverse effects of isoflurane (Forane)?
- Respiratory depression
- Malignant hyperthermia
- Shivering: not due to being cold. Dantrolene helps.
- Possible increase in intracranial pressure: so, up to anesthesiologist but, may be contraindicated for head injuries or brain cancer.
What is malignant hyperthermia?
Disorder in response to inhaled anesthetics that cause dangerous rise in temperature along with muscle rigidity.
Treated with Dantrolene, a direct-acting muscle relaxer, that stops rigidity and the temperature goes down.
This local anesthetic may also be combined with epinephrine:
May be combined with epinephrine for vasoconstriction. This helps with 1. slows bleeding, making sutchering easier but also 2. keeps the lidocaine at the site which helps it last longer.
What is the onset of lidocaine (Xylocaine)?
2 - 5 minutes.
Nursing care: let it sit a couple of minutes to ensure it is indeed numbing the patient before beginning work on the wound.
What is lidocaine (Xylocaine)'s mechanism of action?
Sodium Channel Blocker
Influx of sodium is what's needed for the pain action potential to be formed to create the impulse to the brain. By blocking the sodium channel, there is either a slowed impulse or no impulse, so not feeling the pain.
What are the adverse effects of lidocaine (Xylocaine)?
None if used as a local anesthetic.
Comes is the form of a patch as well that is used over a painful nerve or in preparation of an IV.
This general anesthetic is a low potency drug:
Not great for major procedures... more like dental work OR may be given in combination with another drug for a deeper sedation.
What is the benefit or purpose of using Nitrous oxide?
If needing patient to be somewhat responsive and follow directions as well as experience some pain relief.
What is the onset time of Nitrous oxide?
2 - 5 minutes.
What is the mechanism of action for Nitrous oxide?
GABA receptor agonist
Opioid agonist (provides some pain relief)
What opioid agonist is given by almost any route and is hardly ever referred to by its trade name?
Morphine (Duramorph, Roxanol)
Mechanism of action:
Binds to mu and kappa receptors, so it alters the pain perception (doesn't get rid of it), tells the brain not to recognize it. The sedation aspect also helps with the pain by calming the person down.
What are some adverse effects of morphine?
- sedation / respiratory depression (most important to monitor)
- constipation (due to slowed peristalsis)
- disorientation (brain is clouded)
- euphoria/ floating feeling (often the reason for abuse)
- itching (common and will often be administered with Benadryl)
- peripheral vasodilation (possible hypotension) stay hydrated, dangle off side of bed.
TOLERANCE - becomes less effective because brain gets used to it being there.
Possible Interactions to consider with morphine:
Keep in mind other possible CNS depressants: alcohol, Valium/ benzodiazepine, there'll be an additive effect.
Anti hypertensive... may further dilate vessels causing severe hypotension.
Are they taking an opiod antagonist? If so they will not receive any pain relief.
This drug is a schedule II abuse risk with medicinal purpose:
Highest risk level w/med use.
Ex: heroine and marijuana are schedule I because not recognized with medical use. Schedule II, III, and IV have med use.
Very low risk when used for pain treatment.
Morphine relative contraindications:
- Elderly. More sensitive to CNS depression (respiratory)
- Head injury: may be more difficult to assess any changes to patient's condition due to CNS depression.
- Labor and Delivery/ breastfeeding: crosses placenta and milk
- Lung disease: opiates are very effective cough suppressants... not good with COPD - need them to cough. Plus can cause more resp depression in an already depressed state.
What do we need to keep in mind regarding combination opioid analgesics?
They are mixed with either acetaminophen, aspirin, or ibuprofen... so be careful not to overdose.
Which drug is classified as a mixed opioid-nonopiod agonist?
Weak mu receptor agonist, additionally inhibits the re uptake of serotonin and norepinephrine at the spinal cord.
So, combo of altering pain perception in brain and also an effect on the modulation of the transmission of the pain impulse.
Schedule IV drug, so less of an abuse risk than morphine.
Adverse effects of Tramadol (Ultram):
- Vertigo, dizziness
- N/V, constipation
- Tremor, anxiety (from increase of norepinephrine and serotonin), confusion (drowsiness from mu receptor)
Relative contraindications of Tramadol (Ultram):
- Opioid hypersensitivity ( those who have sensitivity to opioids)
- Lung disease
- Seizure disorder: Tram lowers seizure threshold.
Drug interactions to consider with Tramadol (Ultram):
Other CNS depressants...
Alcohol, morphine, benzodiazepines