Anesthesia Medication Overview PPT Flashcards
Which anesthetic gas is the only one capable of providing analgesia?
Nitrous Oxide
What two desired effects are produced through the use of inhaled volatile anesthetic agents (VAA’s) ?
- Immobility
- Amnesia
What MAC will cause 99% of patients to not show a motor response during surgery?
1.3 MAC
MAC values are _____ in terms of preventing movement from incisional pain.
Additive
Ex. 0.5 MAC Nitrous + 0.5 MAC Isoflurane = 1 MAC VAA
Which anesthetic gas has very low solubility and requires the use of a heated vaporizer?
Desflurane
Which VAA is not irritable to the airway and thus useful for pediatric inductions?
Sevoflurane
Which anesthetic gas is most likely to result in laryngospasm?
Desflurane (Airway irritant that stinks)
What property of Desflurane makes it appropriate for obese patients?
Low lipid solubility = absorbs quick and goes away quick
What VAA is very lipid soluble and what are the consequences of this?
Isoflurane = Long emergence
What anesthetic gas (removing all other variables) would be appropriate for a thoracotomy patient that the surgeon wants to stay intubated in the ICU?
Isoflurane
Which anesthetic gas can precipitate N/V at higher doses?
Nitrous Oxide (>50%)
Which VAA can precipitate tachycardia?
Desflurane
Which anesthetic gas is not suitable for neuro or bowel surgical cases?
Nitrous Oxide (Distending effect from it’s solubility)
The following factors would have what effect on anesthetic requirement?
- Chronic ETOH
- Infancy
- Red hair
- Hyperthermia
These factors would increase anesthetic requirement
Would hypernatremia increase or decrease anesthetic requirement?
Increase
The following factors would have what effect on anesthetic requirement?
- Acute ETOH
- Elderly
- Anemia (Hgb < 5mg/dL)
- Hypercarbia
- Pregnancy
- Hypoxia
- Hypothermia
These factors would Decrease anesthetic requirement
What is the typical induction dose of propofol?
1.5 - 2.5 mg/kg IV
2mg/kg IV
What is the sedation dose of propofol?
25 - 100 mcg/kg/min
What is the TIVA dose of Propofol?
100 - 300 mcg/kg/min
What occurs when Propofol is pushed through a peripheral IV? How is this avoided?
Pain, pre-treat with 1- 2% Lidocaine
________ dosing of propofol is necessary for elderly patients.
Decreased
What are propofol’s effects on the bronchi?
Bronchodilation
Propofol will ______ the SNS response to laryngoscopy.
Suppress
What is the deadly result of Propofol Infusion Syndrome?
Sudden onset severe bradycardia → asystole
Resistant to treatment
What patients are at risk for developing adverse reactions to propofol?
- Head injuries receiving propofol > 58 hours
- High dose infusions (5mg/kg/hr)
What is the mechanism of action of propofol?
Enhances GABA channels to increase Cl⁻ conductance.
What is the mechanism of action of etomidate?
Enhances GABA channels to increase Cl⁻ conductance.
When is etomidate best used?
Induction in hemodynamically unstable patients.
What is the dose of etomidate for induction?
0.3 mg/kg
What is a rare adverse outcome associated with etomidate?
Adrenocortical suppression
Which induction drug is the most causative for PONV?
Etomidate (30%)
Is Ketamine a hypnotic?
No, it is a Dissociative Anesthetic
What is Ketamine’s MOA?
- Depresses neurons of cortex & thalamus
- Stimulates Limbic system
- Activates opioid receptors & subcortical neurons of spinal tract.
What is the adult induction dose of ketamine?
1.5 mg/kg IV
What is the analgesia dose of ketamine?
0.2 - 0.5 mg/kg
What is the IM dose of ketamine used to calm pediatric patients?
4 - 8 mg/kg IM
What medication class is a contraindication to ketamine usage?
MAOI’s (profound increase in system Epi)
When does delirium occur after ketamine induction?
Post-Op (usually in PACU)
What pre-treatment is necessary with ketamine induction?
Glycopyrrolate
Ketamine is sialagogue, Robinol necessary to pre-treat secretions.
What hemodynamic parameter is depressed due to ketamine?
Trick question. None.
↑ PVR, SVR, HR, CO, SNS outflow, etc
Further research indicates this is not necessarily true. Ketamine is a myocardial depressant and will drop CO if the patient is catecholamine depleted.
How are hallucinations associated with Ketamine administration avoided?
Concurrent Benzo administration (versed usually)
Barbs/prop also work but usually patient receiving ketamine won’t tolerate these.
What is the MOA of dexmedetomidine?
Stimulation of α2 receptors → pre-synaptic SNS inhibition
What is the loading dose of dexmedetomidine?
1 mcg/kg over 10 min
What is the infusion dose of dexmedetomidine?
0.2 - 0.7 mcg/kg/hr
What hemodynamic abnormality can occur if precedex is given too quickly?
Hypertension
What are the respiratory effects of dexmedetomidine?
- Minimal respiratory depression
- Anti-sialagogue
- Obstruction still possible
What is the induction dose of methohexital?
1.5 mg/kg
What barbiturate can be used to treat seizures at high doses but is epileptogenic at lower doses?
Methohexital
What are the uses for Methohexital?
Rapid non-painful procedures
- ECT (because it does not depress seizure activity)
- Cardioversion
- Seizure mapping
Morphine has a dose-dependent _______ release.
histamine
This hemodynamic paramater is tyically decreased with administration of higher doses of morphine.
SVR
What is the induction dose of fentanyl?
1.5 - 3 mcg/kg IV
What is the infusion dose of fentanyl?
3 - 6 mcg/kg/hr
What is meperidine’s greatest use?
What dose is utilized?
Useful for post-operative shivering
12.5 mg IV
Meperidine usage is contraindicated with what two things?
- Seizures
- MAOI use
What is Sufentanil’s MOA?
Highly selective μ opioid receptor agonist.
What is the IV push dose for sufentanil?
0.5 - 1 mcg/kg
What is the infusion dose of sufentanil?
0.5 - 1 mcg/kg
What are the benefits and use cases for sufentanil?
- Good for cardiovascular stability
- Post-operative pain control (lasts longer than remi)
What is the loading dose of Remifentanil?
0.5 - 1 mcg/kg over 1 minute
What is the MOA of remifentanil?
μ opioid agonist
What is the infusion dose of remifentanil?
0.125 - 0.375 mcg/kg/min
What is the benefit of remifentanil?
Extremely quick onset and offset
- turn off 6 min before spontaneous ventilation
- 70% MAC reduction when using IV drip
What are the downsides to remifentanil?
- Fast resp depression
- Bradycardia
- Expensive
What receptors does naloxone bind to?
Antagonistic towards
- μ
- κ
- δ
What is the respiratory depression reversal dose of naloxone?
40 - 80 mcg IV
_____ stimulation can be seen with abrupt reversal of analgesia using naloxone.
Cardiac
Naloxone has the capability to cause what severe adverse effect?
Flash Pulmonary Edema
Rank the potency of the following benzodiazepines
- Midazolam
- Lorazepam
- Diazepam
Lorazepam > Midazolam > Diazepam
Lorazepam is 5x more potent than midazolam
and midazolam is 5x more potent than diazepam.
What are the respiratory side effects of benzodiazepines?
- Hypoxic drive to breath is depressed.
- Depressed airway reflexes
- Dose-dependent respiratory depression
What patient populations should caution be utilized when giving benzo’s?
- Chronic COPD
- OSA
- Morbid Obesity
Benzo’s will decrease respiratory drive in these patients due to hypoxic drive depression.
Benzodiazepines are additive/synergistic with opioids.
Synergistic
What are the cardiovascular effects noted with benzodiazepine sedation?
Minimal (possible small drop in BP).
What is the reversal drug and dose of benzodiazepines?
Flumazenil 0.2 mg IV
0.1 mg every minute after to a total of 1mg
What is the duration of action of flumazenil?
30 - 60 min
Much shorter than most benzo’s
Flip for PONV agents information
What is the structure and MOA of succinylcholine?
- 2 ACh molecules bound together
- Bind to post-synaptic receptors and produces depolarization and keeps channel open, disallowing repolarization.
In what patients should Succinylcholine be avoided?
- Malignant Hyperthermia
- Burns
- Paralyzed & bed-bound
- ↑ K⁺ (particularly renal patients)
Why would succinylcholine be dangerous for the bed-bound or renal patient?
These patients have upregulated ACh receptors and SCh administration will result in massive K⁺ efflux.
What benefits does cisatracurium offer over atracurium?
- No histamine release
- Safe in renal failure patients
- No dose change with age or illness
What is the infusion dose of Nimbex (cisatracurium) ?
0.2 mg/kg
0.1 mg/kg if succinylcholine has been administered.
What is the push dose of vecuronium?
- 0.1 mg/kg
- 0.05 mg/kg if succinylcholine has been given.
What is the infusion dose of Vec?
1 - 2 mcg/kg/min
Not great for infusion due to accumulation.
What are the two induction doses of Roc?
0.6 mg/kg
1.2 mg/kg for RSI
What dose of rocuronium should be used if succinylcholine has already been administered?
0.3 mg/kg
What is the infusion dose of rocuronium?
5 - 12 mcg/kg/min
Accumulates much less than vecuronium
T/F. Neostigmine is a direct inhibitor of non-depolarizing NMB’s.
False. Neostigmine is a ACh-esterase inhibitor → ↑ ACh to counteract ND-NMB’s.
Indirect antagonism.
What would occur if Succinylcholine and neostigimine were given concurrently?
SCh would be augmented.
What is the most rapid onsetting AChe inhibitor?
Edrophonium (1-2 min)
What are the onset and duration of neostigmine?
Onset: 7 - 11 min
Duration: 40 - 60 min
What is the onset and duration of glycopyrrolate?
Onset: 2 - 3 min
Duration: 2 hours
What drug is glycopyrrolate given with? Why?
Glycopyrrolate is given just prior to neostigmine to counteract bradycardia.
What is the dosage range for Sugammadex?
2 mg/kg - shallow block
4 mg/kg - moderate block
8 mg/kg - deep block
16 mg/kg - Extreme block (1.2 mg/kg Roc just given)