Exam 4: 14 Apr Anesthesia Pharmacology Adjuncts Flashcards
(113 cards)
1
Q
What are the three subtypes of beta receptors?
A
Beta one, beta two, and beta three
Beta three is generally not relevant in anesthesia.
2
Q
What is the primary focus of beta one drugs?
A
Myocardium
3
Q
What is the primary focus of beta two drugs?
A
Lungs
4
Q
What happens when beta receptors are occupied by agonists?
A
Reduce cyclic AMP, enhances calcium influx
5
Q
What is tachyphylaxis in relation to beta antagonists?
A
Reduced responsiveness to beta antagonists after chronic administration
6
Q
What is the SKIP protocol in anesthesia?
A
Requires a dose of beta blockers within 24 hours of surgery for patients already on them
7
Q
What are common beta blockers mentioned in the discussion?
A
- Metoprolol
- Esmolol
8
Q
Why is Metoprolol preferred over Propranolol?
A
Metoprolol has a longer duration of action and fewer non-specific effects
9
Q
What is phenylephrine used for?
A
Treating hypotension from sympathetic nervous system blockade
10
Q
What type of drug is ephedrine?
A
Indirect sympathomimetic
11
Q
What is the mechanism of action of Sodium Nitroprusside?
A
Causes venous capacitance and can lead to cyanide formation
12
Q
What are the effects of Nitroglycerin?
A
- Controlled hypotension
- Sphincter of Oddi spasm
13
Q
What is Nicardipine used for in blood pressure management?
A
Controlled blood pressure reduction without affecting heart rate
14
Q
What is the advantage of Nicardipine’s slower onset?
A
Provides smoother control of blood pressure
15
Q
What type of patients should avoid sodium nitroprusside?
A
Patients with COPD
16
Q
What is the role of short-acting fentanyl during anesthesia emergence?
A
Immediate pain relief
17
Q
What are the considerations for pain management during emergence from anesthesia?
A
- Use short-acting opioids for immediate relief
- Use longer-acting opioids for sustained relief
18
Q
What are the potential side effects of many anesthetic drugs?
A
- Hypotension
- Bradycardia
19
Q
What is the primary mechanism of action of calcium channel blockers?
A
Selective effects on AV node and arterial beds
20
Q
What is the effect of beta antagonists on heart rate?
A
They decrease heart rate and dysrhythmias
21
Q
During which phase does the myocardium primarily perfuse?
A
Diastole
22
Q
What is the significance of the SKIP protocol for patients on beta blockers?
A
Ensures they receive a dose to improve surgical outcomes
23
Q
Fill in the blank: Beta antagonists prevent catecholamines from binding to the _____ and _____ muscle.
A
Heart, airway smooth
24
Q
True or False: Propranolol is recommended for patients requiring beta blockade in anesthesia.
A
False
25
What is the importance of quick decision-making in anesthesia management?
To effectively manage pain and blood pressure
26
What is the main purpose of beta blockers in treatment?
To manage heart rate and blood pressure
27
Name two examples of beta one selective agents.
* Metoprolol
* Esmolol
28
Which beta blocker is considered the 'mama' of all time beta blockers?
Propranolol (Enderol)
29
What is the primary action of beta one selective agents?
They primarily affect the myocardium
30
What is the significance of Atenolol in beta blocker therapy?
It decreases complications from an MI for up to two years
31
True or False: Non-specific beta blockers can cause hypoglycemia.
True
32
Fill in the blank: The typical dose for Metoprolol is ______ every 10 minutes.
5 milligrams
33
What is the difference in dosing between Metoprolol formulations?
* Immediate-release: 2-3 hours, up to 4 times a day
* Extended-release: 5-7 hours, once a day
34
What is the dosing strategy for Esmolol?
Start with 20-30 mg, then adjust as needed
35
What is a key benefit of Esmolol in anesthesia?
It works quickly to lower heart rate and blood pressure
36
Which beta blocker is known for its rapid action?
Esmolol
37
How do beta blockers interact with calcium channel blockers?
They can have synergistic effects, especially non-specific beta blockers
38
What effect do volatile anesthetics have on the myocardium?
They can cause cardiac depression
39
What is the mechanism of action for alpha one agonists?
They cause vasoconstriction
40
Name an example of an alpha two agonist.
* Clonidine
* Dexmedetomidine
41
What medication is used for hypotension from sympathetic nervous system blockade?
Phenylephrine
42
Fill in the blank: The normal dose for phenylephrine is ______.
100 micrograms
43
What is the effect of phenylephrine on heart rate in patients with aortic stenosis?
It does not cause tachycardia
44
How can phenylephrine be administered to avoid dosing errors?
It can be pre-mixed for safety
45
What is reflex bradycardia?
A decrease in heart rate due to increased vascular resistance
46
What are the two types of alpha receptors?
* Alpha One
* Alpha Two
47
What is the clinical significance of beta blockers in perioperative care?
They help manage blood pressure and reduce complications
48
What is a major side effect of phenylephrine?
Reflex bradycardia
## Footnote
Reflex bradycardia can result in heart rates dropping to the 20s and 30s, as the myocardium slows down its contractions in response to high peripheral resistance.
49
What is the Beta to Alpha blocking ratio of labetalol in its IV form?
7 to 1
## Footnote
This means labetalol has seven times the non-selective beta effect compared to its alpha effect.
50
What is the typical dosing range for labetalol?
2.5 to 10 milligrams
## Footnote
Doses can be given in increments, typically starting at 5 milligrams.
51
Why should propranolol be avoided before intubation?
It is non-specific
## Footnote
Propranolol can cause bronchoconstriction, which is undesirable before intubation.
52
Why is esmolol not recommended for immediate use in surgery?
It doesn't last long
## Footnote
Esmolol's short duration of action makes it less effective for preoperative myocardial protection.
53
What is a significant concern regarding the use of carvedilol in the preoperative setting?
It is only available orally
## Footnote
This route is not suitable for patients who are not able to take oral medications before surgery.
54
Which beta blocker is often preferred for longer-lasting effects during surgery?
Metoprolol
## Footnote
Metoprolol is selected for its longer action compared to labetalol.
55
What is the primary concern when a patient's blood pressure is 210 over 64?
Systolic pressure
## Footnote
The high systolic pressure is the main concern, while the diastolic pressure is acceptable.
56
Which drug is suitable for quickly lowering systolic blood pressure?
Esmolol
## Footnote
Esmolol is effective due to its fast action, particularly in urgent situations.
57
What are sympathomimetics primarily used for?
To increase blood pressure
## Footnote
They also increase myocardial contractility but are primarily indicated for hypotension.
58
What is the prototypical indirect sympathomimetic drug?
Ephedrine
## Footnote
Ephedrine causes the release of norepinephrine, leading to sympathomimetic effects.
59
What is the typical IV dose range for epinephrine in cardiac cases?
2 to 8 micrograms
## Footnote
This dosage is specific to the context of cardiac surgery.
60
What is the difference in use between epinephrine and vasopressin in cardiac cases?
Epinephrine is used more in cardiac cases; vasopressin is used less
## Footnote
This may vary based on surgical practices and protocols.
61
What is a common practice regarding ephedrine in obstetric anesthesia?
Administering it IM preemptively
## Footnote
This is done to avoid hypotension during spinal anesthesia in C-sections.
62
What has recent research indicated about phenylephrine vs. ephedrine for treating hypotension in C-section patients?
Higher umbilical pH with phenylephrine
## Footnote
Higher umbilical pH indicates better neonatal well-being at delivery.
63
What is the main difference in umbilical pH between mothers who received phenylephrine and those who received ephedrine?
Higher umbilical pH in mothers who received phenylephrine
## Footnote
A higher umbilical pH indicates better neonatal well-being.
64
What does a good neonatal pH indicate about blood supply?
Stable blood supply to the placenta and neonate
## Footnote
A good neonatal pH suggests that the baby's heart rate has been stable before delivery.
65
What is vasopressin and where is it normally stored?
A synthetic version of ADH, normally stored in the posterior pituitary
## Footnote
Vasopressin stimulates B1 receptors to cause vasoconstriction.
66
In what situation is vasopressin particularly effective?
In ACE inhibitor induced hypotension
## Footnote
Vasopressin is an alternative when ephedrine is ineffective.
67
What are the side effects of vasopressin?
Coronary vasoconstriction, decreased platelet counts
## Footnote
Side effects may affect clinical decisions, especially in myocardial ischemia.
68
How do you calculate mean arterial pressure (MAP)?
2 x diastolic + systolic divided by 3
## Footnote
Example: For a blood pressure of 70/30, MAP would be 43.
69
What is the significance of a MAP of 43?
Indicates low perfusion to vital organs
## Footnote
Low MAP can lead to inadequate blood flow to heart, liver, brain, and kidneys.
70
What should be done if blood pressure is low during anesthesia induction?
Consider reducing anesthetic agents and administering IV fluids or vasopressors
## Footnote
Quick actions can stabilize blood pressure before further interventions.
71
What is a potential risk of administering epinephrine in a hypotensive patient?
Can cause excessive vasoconstriction and worsen myocardial ischemia
## Footnote
Careful consideration is needed for patients with coronary artery disease.
72
When might phenylephrine be a suitable choice for a hypotensive patient?
If the patient is on beta blockers
## Footnote
Phenylephrine can be used since beta agonists may not be effective.
73
What type of fluid is albumin and how does it differ from crystalloids?
Colloid fluid; stays in the intravascular space better than crystalloids
## Footnote
Albumin is more expensive and may have allergic reactions.
74
Why might isotonic fluids not stay in the vascular system for long?
They leak out into the interstitial space
## Footnote
This is a common misconception about isotonic fluids.
75
What factors influence the decision to use albumin over crystalloids?
Cost, volume needs, risk of hypervolemia and allergic reactions
## Footnote
Clinicians must assess patient-specific factors before fluid choice.
76
What is an important consideration when transfusing blood products?
Hemoglobin levels and patient comorbidities
## Footnote
Transfusion thresholds may change based on the patient's condition.
77
What is the initial fluid resuscitation volume suggested for a patient during a hysterectomy?
500 mL to 1 liter
## Footnote
This volume may be adjusted based on the patient's condition and response.
78
What is the purpose of using albumin in fluid resuscitation?
To provide a more effective volume expansion when crystalloids are insufficient.
79
What hemoglobin threshold is typically used for transfusion in patients with renal failure?
7 g/dL
## Footnote
Patients with renal failure may have lower hemoglobin levels without requiring transfusion.
80
What hemoglobin level is generally used as a transfusion threshold for patients with coronary disease?
10 g/dL
81
True or False: The amount of blood loss during a procedure affects the decision to transfuse.
True
82
What is the role of nitric oxide in the cardiovascular system?
It inhibits calcium influx and causes vasodilation.
83
What is a primary characteristic of sodium nitroprusside?
It has an instantaneous onset of action.
84
What is a major concern when using sodium nitroprusside for prolonged periods?
Cyanide toxicity due to accumulation.
85
What is the initial dosing recommendation for sodium nitroprusside?
0.3 mcg/kg/min
86
What is the maximum dose for sodium nitroprusside?
2 mcg/kg/min
87
What types of surgeries is sodium nitroprusside particularly useful for?
Hypertensive crises and invasive vascular surgeries.
88
What is the effect of nitroglycerin on coronary arteries?
It dilates some coronary arteries but not those that are completely occluded.
89
Fill in the blank: Nitroglycerin has a high degree of _______ when used continuously.
tolerance
90
What is one clinical use for nitroglycerin in surgical settings?
To manage controlled hypotension.
91
What is a common alternative to nitroglycerin for relieving sphincter of Oddi spasm?
Glucagon
92
What is a characteristic of hydralazine regarding its onset and duration of action?
It has a slow onset and a long duration.
93
What is the typical peak plasma concentration time for hydralazine?
1 hour
94
What potential issue can arise from using hydralazine in the operating room?
Delayed blood pressure control.
95
List two common vasodilators discussed.
* Sodium nitroprusside
* Nitroglycerin
96
True or False: Nitroglycerin works primarily on the arterial side of the vasculature.
False
97
What happens to mixed venous saturations during cyanide toxicity?
They rise due to tissue acidosis.
98
What is a significant drawback of sodium nitroprusside?
It does not lower blood pressure quickly and may overshoot the target pressure
## Footnote
Sodium nitroprusside may cause a rapid drop in blood pressure, but it can also lead to dangerously low levels if not monitored closely.
99
Which calcium channel blocker is primarily used for sudden extreme hypertension?
Cardene
## Footnote
Cardene is preferred for its ability to provide controlled vasodilation without drastically affecting heart rate.
100
What are the two types of selectivity seen in calcium channel blockers?
AV node selectivity and arterial bed selectivity
## Footnote
AV node selective blockers decrease heart rate while arterial bed selective blockers promote vasodilation.
101
What is the initial dosing strategy for Cardene?
Starts at 5 mg/hour, increasing by 2.5 mg/hour up to four times
## Footnote
This slow titration helps avoid overshooting the desired blood pressure.
102
What is the main advantage of Cardene compared to other calcium channel blockers?
It provides good coronary and peripheral dilation without significantly depressing the myocardium
## Footnote
This characteristic allows for blood pressure reduction while maintaining myocardial perfusion.
103
How does nitroglycerin primarily work to manage blood pressure?
It alters venous capacitance
## Footnote
Nitroglycerin primarily acts as a venous vasodilator, which helps to reduce preload.
104
True or False: Hydralazine provides immediate blood pressure control.
False
## Footnote
Hydralazine is not suitable for immediate blood pressure control as it takes time to act.
105
What medication is associated with the formation of cyanide when interacting with oxyhemoglobin?
Sodium nitroprusside
## Footnote
The interaction can lead to toxicity, which is a critical consideration during its use.
106
What is the expected mechanism of action of labetalol?
Beta-1 adrenergic blockade with some alpha activity
## Footnote
Labetalol's mixed action allows it to lower blood pressure without significantly affecting the lungs.
107
What intervention might be necessary if a patient’s blood pressure is climbing post-surgery?
Administer a short-acting opioid for immediate pain relief
## Footnote
Short-acting opioids can help control pain quickly, which may help stabilize blood pressure.
108
Fill in the blank: The initial intervention for a patient waking up with elevated blood pressure might be to increase _______.
opioid analgesia
## Footnote
Increasing opioid analgesia can help manage pain, which is a common cause of elevated blood pressure in post-operative patients.
109
What should be considered if a patient is intubated and their blood pressure is climbing?
The possibility of pain and the need for sedation
## Footnote
Intubated patients can still experience pain, which may elevate blood pressure.
110
Which two medications could be administered together for pain relief in a postoperative patient?
Fentanyl for immediate relief and Dilaudid or morphine for longer relief
## Footnote
This combination provides both immediate and sustained analgesia.
111
What is the onset time for fentanyl when administered?
Rapid onset
## Footnote
Fentanyl acts quickly, making it suitable for immediate pain management.
112
What is a potential risk of giving short-acting opioids in a postoperative setting?
Need for frequent redosing
## Footnote
Short-acting opioids require repeated administration, which may be impractical in recovery settings.
113
What could be an alternative intervention if a patient's blood pressure continues to rise post-surgery?
Remove the endotracheal tube to assess if stimulation is causing hypertension
## Footnote
If the patient is stable, extubating may reduce stimulation and help lower blood pressure.
