Mod2: Cardiac Surgery - BASIC ANESTHESIA TECHNIQUES Flashcards
BASIC ANESTHESIA TECHNIQUES
The goals of induction are for it to be?
A smooth transition from awake to sleep
With minimal hemodynamic effects
Reliable loss of consciousness
Sufficient depth of anesthesia to prevent SNS response to laryngoscopy/intubation
BASIC ANESTHESIA TECHNIQUES
Which anesthetic technique is generally used to acheive the goals of induction?
Moderate to high-dose narcotic technique
(<em>Fentanyl</em> 10-100 mcg/kg)
Supplemented with Etomidate (0.1-0.3 mg/kg) or
Propofol (1-2.5 mg/kg)
Depending on the LV function
BASIC ANESTHESIA TECHNIQUES
At which point during induction would a muscle relaxant be administered?
Once loss of consciousness is confirmed
Remember, “Hearing is the last thing to go” , so
Be midful of conversations at this time
BASIC ANESTHESIA TECHNIQUES
Which muscle relaxants are typically used for induction of anesthesia in cardiac surgery?
Rocuronium
(0.6-1.2 mg/kg)
Succinylcholine
(0.5-1 mg/kg) if RSI needed
BASIC ANESTHESIA TECHNIQUES
Which other drugs may be used to compliment anesthesia induction in cardiac surgery?
Esmolol, Lidocaine, NTG
BASIC ANESTHESIA TECHNIQUES
Why is the High dose Narcotic Technique superior to others?
Associated with minimal cardiac depression
Has the ability to provide hemodynamic stability
BASIC ANESTHESIA TECHNIQUES
What are the drawbacks of the High dose Narcotic Technique?
Do not consistently prevent hypertensive responses during periods of high stimulation
Therefore, must be paired with inhalational agents and vasodilators
Do not provide amnesia; patient recall remains a potential problem; hence must be paired with Benzodiazepines
May produces significant bradycardia; which may be exasperated by other drugs (e.g., Vecuronium)
May cause Chest wall rigidity, especially high doses; consider low-dose (priming) of non-depolarizing muscle relaxant prior to administration (e.g., 5mg of Rocuronium)
May prolongs emergence and extubation in the ICU; which is a bad thing because most centers/surgical teams would like to “fast track” patients, extubating within 4-6 hours post-op
BASIC ANESTHESIA TECHNIQUES
Why does the High narcotic technique require pairing with with inhalational agents and vasodilators?
It does not consistently prevent hypertensive responses during periods of high stimulation
BASIC ANESTHESIA TECHNIQUES
Why does the High narcotic technique require pairing with Benzodiazepines?
Because it does not provide amnesia
Patient recall remains a potential problem
BASIC ANESTHESIA TECHNIQUES
The High narcotic technique may produces significant bradycardia; which may be exasperated by other drugs (e.g.,
Vecuronium
BASIC ANESTHESIA TECHNIQUES
The High narcotic technique may cause Chest wall rigidity, especially high doses. Which drugs could be given prior to administration of narcotics to prevent this chest wall rigidity?
Low-dose (priming) of non-depolarizing muscle relaxants
(e.g., 5mg of Rocuronium)
BASIC ANESTHESIA TECHNIQUES
The High narcotic technique may prolong emergence and extubation in the ICU. Why is this a bad thing?
Most centers/surgical teams would like to “fast track” patients, extubating within 4-6 hours post-op
BASIC ANESTHESIA TECHNIQUES
Between Fentanyl and Sufentanil which is more used for High dose Narcotic Technique?
Fentanyl > Sufentanil
BASIC ANESTHESIA TECHNIQUES
Since the time from when the pt is anesthetized to when the incision is made is variable, is it a reasonable idea to reduce the depth of anesthesia? Explain.
Time from when the pt is anesthetized to when the incision is made is variable
Pt must be shaved, prepped and draped during this time
There will be low levels of stimulation
Keeping in mind the potential for recall, it’s a reasonable idea to reduce the depth of anesthesia in an attempt to reduce the amount of vasodilation from the anesthetic agents
BASIC ANESTHESIA TECHNIQUES
Why should you consider using lower dose of Volatile anesthetics when utilizing the Mixed IV/Inhalational technique to maintain anesthesia Pre-incision?
Volatile anesthetics may cause myocardial depression
Consider lower levels
BASIC ANESTHESIA TECHNIQUES
What are advantages of using lower dose of volatile anesthetics when utilizing the Mixed IV/Inhalational technique to maintain anesthesia Pre-incision?
Ischemic preconditioning
Decreased myocardial O2 demand with volatile anesthetics
BASIC ANESTHESIA TECHNIQUES
Which drugs could be intermittently given as boluses when utilizing the Mixed IV/Inhalational technique to maintain anesthesia before incision?
Intermittent boluses of opioids and muscle relaxants
Fentanyl 10-100 mcg/kg
Sufentanil 5-20 mcg/kg
BASIC ANESTHESIA TECHNIQUES
In the maintenance of anesthesia before incision, and because of the low levels of stimulation, hypotension may occur. How should it be managed?
Reduce depth of anesthesia
Administer vasopressors
(especially if the pt has ventricular dysfunction or aortic stenosis)
MAKE SURE TO ANTICIPATE INCISION
BASIC ANESTHESIA TECHNIQUES
How should the arms be positioned?
Tucked to the side
Make sure padding is appropriate to avoid nerve damage to either the ulnar or radial nerve
BASIC ANESTHESIA TECHNIQUES
Pt is also pulled down to the foot of the bed, and either and Ether screen or “male stand-like” table is placed at the head of the table. What should you be concerned about?
Making sure all IV lines and the ET tube are free from tugging
BASIC ANESTHESIA TECHNIQUES
The pt will also be completely exposed for positioning, prepping, and draping. What should you be concerned about?
Hypothermia
Temperature is very important to monitor
Warm the room or turn the underbody water warmer on to keep an appropriate temperature
PREBYPASS PERIOD - Incision to bypass
The minimal stimulation phase is followed by high stimulation that can have which effects?
Tachycardia
HTN
Ischemia
PREBYPASS PERIOD - Incision to bypass
The minimal stimualtion phase is followed by high stimulation that can produce Tachycardia, HTN, Ischemia. How should this period be managed?
Anticipate events
Deepen anesthesia
Use narcotics
Use vasodilators in moderation
PREBYPASS PERIOD - Incision to bypass
The anesthetic agents should be adjusted appropriately to anticipate incision, sternotomy/sternal retraction, Pericardotomy/Cardiotomy, Aortic root dissection, taking caution to not overdose the pt, as this could cause:
Hypotension
PREBYPASS PERIOD - Incision to bypass
NTG is typically given in increments to avoid substantial drop in BP. Why is NTG a great agent to treat acute HTN?
It has Fast onset, and
Short duration of action
PREBYPASS PERIOD - Incision to bypass
During sternal sawing, the anesthesia provider must deflate the lungs by switching the ventilator off; why?
To reduce chance of sawing injury to the right ventricle