Pharmacology Review Flashcards
1
Q
Which inhaled gas provides analgesia?
A
Nitrous Oxide
2
Q
What are the two actions of volatile anesthetics?
A
- Produce immobility (↓ muscle tone)
- Produce amnesia
3
Q
What inhaled gas increases skeletal muscle tone?
A
Nitrous Oxide
4
Q
Inhaled anesthetics produce immobility via actions on the __________.
A
Spinal Cord
5
Q
What is Minimum Alveolar Concentration (MAC)?
A
Alveolar concentration at which 50% of patients will not show a motor response to surgical incision.
6
Q
Nitrous Oxide Effect on
BP:
HR:
SVR:
CO:
A
Nitrous Oxide Effect on
BP: N/C
HR: N/C
SVR: N/C
CO: N/C
7
Q
Isoflurane Effect on
BP:
HR:
SVR:
CO:
A
Isoflurane Effect on
BP: ↓ ↓
HR: ↑
SVR: ↓ ↓
CO: N/C
8
Q
Desflurane Effect on
BP:
HR:
SVR:
CO:
A
Desflurane Effect on
BP: ↓ ↓
HR: N/C or ↑
SVR: ↓ ↓
CO: N/C or ↓
9
Q
Sevoflurane Effect on
BP:
HR:
SVR:
CO:
A
Sevoflurane Effect on
BP: ↓
HR: N/C
SVR: ↓
CO: ↓
10
Q
Nitrous Oxide Effect on
TV:
RR:
Resting PaCO2:
Challenge PaCO2:
A
Nitrous Oxide Effect on
TV: ↓
RR: ↑
Resting PaCO2: N/C
Challenge PaCO2: ↑
11
Q
Isoflurane Effect on
TV:
RR:
Resting PaCO2:
Challenge PaCO2:
A
Isoflurane Effect on
TV: ↓ ↓
RR: ↑
Resting PaCO2: ↑
Challenge PaCO2: ↑
12
Q
Desflurane Effect on
TV:
RR:
Resting PaCO2:
Challenge PaCO2:
A
Desflurane Effect on
TV: ↓
RR: ↑
Resting PaCO2: ↑ ↑
Challenge PaCO2: ↑ ↑
13
Q
Sevoflurane Effect on
TV:
RR:
Resting PaCO2:
Challenge PaCO2:
A
Sevoflurane Effect on
TV: ↓
RR: ↑
Resting PaCO2: ↑
Challenge PaCO2: ↑
14
Q
Nitrous Oxide Effect on
Cerebral Blood Flow:
ICP:
Cerebral Metabolic Rate:
Seizures:
A
Nitrous Oxide Effect on
Cerebral Blood Flow: ↑
ICP: ↑
Cerebral Metabolic Rate: ↑
Seizures: ↓
15
Q
Isoflurane Effect on
Cerebral Blood Flow:
ICP:
Cerebral Metabolic Rate:
Seizures:
A
Isoflurane Effect on
Cerebral Blood Flow: ↑
ICP: ↑
Cerebral Metabolic Rate: ↓ ↓
Seizures: ↓
16
Q
Desflurane Effect on
Cerebral Blood Flow:
ICP:
Cerebral Metabolic Rate:
Seizures:
A
Desflurane Effect on
Cerebral Blood Flow: ↑
ICP: ↑
Cerebral Metabolic Rate: ↓ ↓
Seizures: ↓
17
Q
Sevoflurane Effect on
Cerebral Blood Flow:
ICP:
Cerebral Metabolic Rate:
Seizures:
A
Sevoflurane Effect on
Cerebral Blood Flow: ↑
ICP: ↑
Cerebral Metabolic Rate: ↓ ↓
Seizures: ↓
18
Q
Nitrous Oxide Effect on Nondepolarizing blockade
A
↑
19
Q
Isoflurane Effect on Nondepolarizing blockade
A
↑ ↑ ↑
20
Q
Desflurane Effect on Nondepolarizing blockade
A
↑ ↑ ↑
21
Q
Sevoflurane Effect on Nondepolarizing blockade
A
↑ ↑
22
Q
Nitrous Oxide Effect on
Renal Blood Flow:
GFR:
U/O:
A
Nitrous Oxide Effect on
Renal Blood Flow: ↓ ↓
GFR: ↓ ↓
U/O: ↓ ↓
23
Q
Isoflurane Effect on
Renal Blood Flow:
GFR:
U/O:
A
Isoflurane Effect on
Renal Blood Flow: ↓ ↓
GFR: ↓ ↓
U/O: ↓ ↓
24
Q
Desflurane Effect on
Renal Blood Flow:
GFR:
U/O:
A
Desflurane Effect on
Renal Blood Flow: ↓
GFR: ↓
U/O: ↓
25
Sevoflurane Effect on
Renal Blood Flow:
GFR:
U/O:
Sevoflurane Effect on
Renal Blood Flow: ↓
GFR: ↓
U/O: ↓
26
All inhaled anesthetics will have this effect on hepatic blood flow.
Decrease hepatic blood flow.
27
Describe key characteristics of Desflurane
* Airway irritant (Smells funny, stinks) - don't use on pt with asthma or smokers
* Cause ↑ HR if titrated up quickly
* Very low solubility (fast onset, fast off)
* Needs a special heated vaporizer
* Very $$$
28
Describe key characteristics of Sevoflurane
* Nice smell, great for pediatric induction, non-irritable
* Can cause emergence delirium in kids
* Has been indicated to cause nephrotoxicity in rats → Compound A
29
Describe key characteristics of Isoflurane
* Most lipid-soluble of the inhaled anesthetics (longer emergence)
* Very suitable in longer cases or sick patients expected to stay on the vent
* Cheap
30
Describe key characteristics of Nitrous
* Not a solo anesthetic gas, used as an adjunct
* Only inhaled anesthetic to provide analgesia
* N/V in high doses
* Do not use in neuro or bowel cases (nitrous air will diffuse out and increase pressure in enclosed space)
31
At what age will the highest MAC be used for an infant?
Highest MAC is used at 6 months.
32
Factors that increase anesthetic requirements
* Chronic EtOH use
* Infants
* Red hair
* Hypernatremia
* Hyperthermia
33
Factors that decrease anesthetic requirements
* Acute EtOH use
* Old Pts
* Hyponatremia
* Hypothermia
* Anemia (Hgb < 5 g/dL)
* Hypercarbia
* Hypoxia
* Pregnancy
34
Why use anesthetic gases?
* **Speed of onset**
* **Titratable**
* Potent (narrow therapeutic window)
* Little/ no metabolism: gas in/gas out
* Available measures: watching what pt breathes in and out tells us what is in the pt's brain
35
Dose of Propofol for
Induction:
Sedation:
TIVA:
Induction: 2mg/kg IV
Sedation: 25-100 mcg/kg/min
TIVA: 100-3000 mcg/kg/min
36
What is used to mitigate the pain of propofol IV push during induction?
* 1-2% Lidocaine
37
Benefits of propofol
* Patient can wake up very quickly
* ↓ PONV, anti-emetic
* Dose rarely needs to be changed for renal or liver disease
* Bronchodilator
* Suppresses SNS response to laryngoscopy, best drug to blunt larynx
38
What patient population do you want to avoid propofol in?
* Avoid propofol in cardiac and CAD pts
* Propofol reduces arterial blood pressure, heart rate, and myocardial contraction significantly
39
Problems with long-term (>58 hours) and high-dose propofol infusion (5 mg/kg/hr)
* Lipidemia
* Fatty infiltrates of the liver
* Enlarged liver
* Metabolic acidosis
* Rhabdomylosis
* Myoglobinuria
* Propofol Infusion Syndrome (PRIS)
40
What induction drug is used for cardiovascular stability?
* Etomidate
* Best used in patients with poor cardiac status
41
What is the adverse effect of etomidate?
* Seizures
* Adrenocortical Suppression (prolonged hypotension - give 100 mg hydrocortisone)
* PONV in 30% of patients (vomit-date)
42
Etomidate Preparation
0.2% solution (2mg/mL)
43
Etomidate induction dose
0.3 mg/kg
| Like propofol, there will be pain on injection
44
What is the mechanism action of ketamine?
* Noncompetitive NMDAR antagonist
* Dissociative anesthesia, not a hypnotic
* Depresses neuronal function of the cortex and thalamus
* Activates opioid receptors and subcortical neurons in the spinal tract → Intense analgesia and amnesia
45
Use of Ketamine
* Dissociative anesthesia
* Pain relief acute/chronic
* Adjunct to decrease other anesthesia drugs
* ↓ Narcotic use
46
The most common ketamine preparation
* 5% solution (50 mg/mL)
47
Dose of Ketamine for
Adult Induction
Intense Analgesia
Pediatric Induction
Adult Induction: 1.5 mg/kg IV
Intense Analgesia: 0.2-0.5 mg/kg IV
Pediatric Induction: 4-8 mg/kg IM
| Unlike propofol and etomiate, ketamine does not cause pain on injection
48
What is contraindicated when using ketamine
* MAOI's
* ↑ Epinephrine (↑ HR, ↑ BP)
49
High doses of ketamine (4-5 mg/kg) will have this effect on pts.
Emergence Delirium (treat with benzos)
50
Cardiovascular Effects of Ketamine
* ↑ SVR
* ↑ PVR
* ↑ CO
* ↑ SNS outflow
* ↑ Epi and NorEpi (inhibit reuptake)
51
Ketamine's effect on respiratory tract
* Intense bronchodilator can treat status asthmaticus
* Airway tone remains intact
52
What does ketamine do to salivary secretions?
* ↑ Salivary secretions
* Pre-treat with Robinol 0.1 mg (anti-sialagogue) or Benadryl
53
Mechanism of dexmedetomidine
Stimulation of alpha-2 receptors causes pre-synaptic inhibition (turns down SNS).
54
Dexmedetomidine's effect on α2A receptor.
* **Sedation**
* Hypnosis
* Sympatholysis
55
Dexmedetomidine's effect on α2B receptor.
* Vasoconstriction
* **Anti-shivering**
* **Analgesia**
56
Dexmedetomidine's effect on α2C receptor.
* Learning
* Startled Response
57
Preparation of precedex
* 2 mL vials
* 100 mcg/ mL
* Reconstitute with 50 mL to get 4 mcg/mL
58
What is the loading dose of precedex?
0.5 -1.0 mcg/kg over 10 minutes
59
What is the infusion rate of precedex?
0.2-0.7 mcg/kg/hr
60
What happens if precedex is given too fast?
* Transient hypertension and bradycardia
61
Respiratory effects of precedex
* Minimal respiratory depressant (respiratory sparing)
* Anti-sialagogue
* Normal ABG, no change in TV or RR
* Caution in pt w/ OSA
62
Besides the sedative effects, what are 4 other benefits of using precedex?
* Widens thermoregulation/ Anti-shivering
* Decrease muscle rigidity seen with high-dose opioids
* Drug addicts and EtOH withdrawal are offset
* Chronic pain pts become extremely tolerant
63
Methohexital Uses
* Rapid non-painful procedures
* ECT therapy
* Cardioversion
* Mapping seizure focus - helps pts to continually seize
64
Methohexital adult dosing
1.5 mg/kg
65
Adverse side effects of Methohexital
* Myoclonus/Seizures at low doses (used to treat seizures at high doses)
* Hiccups
* Airway irritability
66
What is the post-op pain dose for morphine?
5-20 mg IV titrated
67
Morphine consideration for intrathecal catheter administration
Potential for delayed respiratory depression up to 24 hours or longer after intrathecal catheter administration
68
Morphine will cause dose-dependent _________ release.
histamine
## Footnote
Morphine will not be a good choice for someon who is already hypotensive
69
What is the active metabolite for morphine?
morphine-6- glucuronide
70
What pt population will have a prolonged morphine half-life?
* Elderly
* Liver failure pt
* Renal failure pt
71
Hydromorphone/Dilaudid is how many times more potent than morphine?
7 times more potent, but less histamine release
72
Which narcotic is favored by many anesthetic providers toward the end of the surgery?
* Hydromorphone (Dilaudid)
* 2-4 hour duration
* Works very slow, 15 minute onset
73
What is the dosing of fentanyl (sublimaze) during the first hour of surgery?
1-5 mcg/kg
74
What is the infusion rate of fentanyl (sublimaze) during surgery?
3-6 mcg/kg/hour
Turn off one hour before breathing.
75
Fentanyl should be dosed by what kind of weight?
Ideal Body Weight
76
Meperidine (Demerol) has an affinity for which opioid receptors?
* Mu
* Kappa
* Delta
77
Dose of Meperidine for post-op shivering.
* 12.5 mg IV
78
The active metabolite for meperidine can cause this effect.
* Seizures
79
Meperidine is contraindicated with which drug?
* MAOI's
* Meperidine blocks the reuptake of serotonin
80
What is the induction dose of Sufentanil (Sufenta)?
* 0.3 - 1 mcg/kg
81
What is the infusion dose of Sufentanil (Sufenta)?
* 0.5 - 1 mcg/kg/hr
* If surgery is < 2 hours, turn infusion off 30 mins before breathing
* If surgery is > 2 hours, turn infusion off 45 mins before breathing
82
Benefits of using sufentanil
* CV Stable
* Good for infusion
* Good for post-op pain control after infusion (stays in the system longer than remifentanil)
83
What is the loading dose of Remifentanil (Ultiva)?
0.5 - 1.0 mcg over 1 minute
84
What is the infusion dose of Remifentanil (Ultiva)?
0.125 - 0.375 mcg/kg/min
Turn off the infusion 6 minutes before breathing.
85
How is Remifentanil metabolized?
Plasma esterase (independent of organ function)
86
Remifentanil can have a ___-% reduction of MAC when used as an infusion.
70%
87
Use of Remifentanil
* Neuro
* Carotid endarterectomy
* Eye blocks
* TIVA
88
Considerations for using Remifentanil
* MUST cover post-op pain with another drug (quick on and off)
* Quick respiratory depression (can substitute for Sch for induction)
* Bradycardia
* Expensive
89
What is the most common PO opioid used?
Oxycodone and Tramadol
90
What can be used to treat pruritis without reversing analgesia?
Partial agonist/antagonist narcotics (methadone, nubaine, stadol, buprenex)
91
What is the dose of Naloxone (Narcan) for respiratory depression reversal?
40-80 mcg IV
| Comes in 400 mcg/mL vial
92
Adverse effects of Naloxone (Narcan)
* Potential for flash pulmonary edema
* Cardiac stimulation r/t abrupt reversal of analgesia
* Can wear off before narcotic, might need administration
93
Besides opioid reversal, what can Narcan treat?
* Pruritis
* Urinary Retention
* Muscle Rigidity
* Biliary Spasm (Oddi spasm)
94
What are the pharmacology effects of benzodiazepam?
* Sedation
* Anxiolysis
* Hypnotic
* Anticonvulsant
* Mediate skeletal muscle relaxation
95
Rank the three most potent benzos.
1. Lorazepam (5x more than Midazolam)
2. Midazolam (5x more than Diazepam)
3. Diazepam
96
CV effects of Benzos
* Minimal effect with sedative dose
* May get a small drop in BP with sedation (minimal)
97
Respiratory effects of Benzos
* Dose-dependent respiratory depression
* Depresses airway reflex and ability to swallow (high doses)
* Hypoxic drive to breathe is DEPRESSED
98
Typically, CO2 drives our breathing. However, what patient population uses oxygen/hypoxia to trigger breathing?
1. Chronic COPD
2. Sleep Apnea
3. Morbid Obesity
99
Dose for Benzo Reversal, Flumazenil (Ramazicon)
0.2 mg
Repeat 0/1 mg IV every minute to a total of 1 mg in the first hour and 3 mg maximum dose.
100
An overdose of Flumazenil can cause what adverse effects?
Seizures
101
Which N/V agent has anti-inflammatory properties and is long-acting?
* Decadron
102
This N/V agent is very safe, difficult to overdose and very effective. Just watch for prolonged QT interval on the EKG.
* Zofran
103
This N/V agent is not used as much anymore. Watch the QT interval, and can cause sedation/confusion
* Droperidol
104
This N/V agent works on the dopamine receptor. Can cause forward GI motility, can cause anxiety, and EPS side effects.
* Metoclopramide (Reglan)
105
This N/V agent is a potent antihistamine.
* Benadryl
106
These are very effective for those with motion sickness.
* Scopolamine patches
107
This is an H2 blocker that can decrease stomach acid but can reduce N/V.
FDA-approved for morning sickness
* Pepcid
108
N/V agent used as a rescue drug, sedation qualities, and extravasation can result in limb loss
* Phenergan
109
This drug has anti-emetic properties and can be used as a last-ditch rescue.
Can also be used in TIVA and avoid gas to ↓ N/V in high risk pt.
* Propofol
110
Newer, $$$ drug, for use in very high-risk pts.
NK-1 Receptor Antagonist.
* Emend (Aprepitant)
111
Describe how Succinylcholine works as a depolarizing NMB.
* Succinylcholine is composed of 2 ACh molecules bound together.
* It binds to the ACh-R at the NMJ and mimics ACh
* Succinylcholine opens the channel and allows depolarization of the motor endplates
* Channel stays open and does not reset, causing paralysis
112
Considerations for using Succinylcholine
* MH Trigger
* Dangerous to use in burn patients (↑K+)
* Renal patients (↑K+)
113
Compared to Atricurium, Cisatracurium does not cause _______-
Histamine release
114
This NMBD is the drug of choice for renal patients as it is metabolized in the blood (organ-independent).
* Cisatracurium (Nimbex)
115
What is the advantage of using vecuronium over rocuronium?
Vecuronium is a lot more predictable.
116
Describe the metabolism of rocuronium.
* Minimal to no metabolism
* No active metabolite
* Excreted unchanged in the kidneys
* Excreted unchanged in the bile
117
Describe the metabolism of vecuronium.
* 30-40% hepatic metabolism
* Active metabolite- 80% potency of the parent compound
* May accumulate in renal failure
118
What neuromuscular reversal agent is used in pediatrics?
* Edrophonium
119
How do Acetylcholinesterase inhibitors (Neostigmine) work to reverse non-depolarizing paralytics?
Neostigmine binds to acetylcholine esterase at the NMJ and ↑ the concentration of ACh.
120
What is the adverse effect of the neuromuscular reversal agent?
Bradycardia
Use anticholinergic agent (robinul) to counter this effect
121
What is the effect of glycopyrrolate when paired with neostigmine?
* Tachycardia
* Bronchodilation
* Antisialagogue
Robinul does not cross the BBB, no sedative effect
## Footnote
Give glycopyrrolate first before neostigmine or just mix the two together.
122
Sugammadex dose for shallow/medium blockade
2 mg/kg
123
Sugammadex dose for deep blockade
4 mg/kg
124
Sugammadex dose for immediate reversal after 1.2 mg/kg rocuronium after 3 minutes.
16 mg/kg
125
What is the best drug of choice to treat a patient who is just tachycardic and normotensive?
* Esmolol (Beta 1)
126
What is the best drug of choice to treat a patient who is tachycardic and hypertensive?
* Labetalol (Nonselective Beta)
127
What is the best drug of choice to treat a patient who is bradycardiac and hypertensive?
* Hydralazine
128
What is Propofol Infusion Syndrome?
Sudden onset of bradycardia that progresses to asystole and is resistant to treatment
