Intraoperative Management CV Surgery Flashcards
8 steps for preparation of administering anesthesia during open heart surgery?
- enter correct weight in to pumps
- check all the pumps and tubing to make sure they are labeled and are indeed what they say they are
- check airway tools
- draw up narcs
- dilute 100 mcg nitro in 10 mL (TV) to make 10mcg/mL
- draw up heparin 300U/kg
- review plan w CRNA and MD
- review plans for catastrophic events
Dose of heparin to have available in an emergency?
3 mg/kg or 300 U/kg
Before meeting the patient before surgery, why should you check w the charge CRNA?
make sure patient doesn’t need to be picked up because they need to be monitored or have IABP
What MUST you check about the procedure before starting the art line?
if it is a radial artery harvest
What time do you have to be in the OR by?
0715
Who is most likely to cardiac arrest (I think this is on induction)? And what should you do to prepare?
proximal left main disease or left main equivalent, severe mitral stenosis, severe AS (AVA
What is the goal for opioid use during heart surgery?
modest use/ 2.5-3 mcg/kg over the course of the surgery
When does Dr. White give versed for open heart surgery?
holding room, when arrive in OR, when go on pump, when warming, and right before SICU: she gives a total of 6-8 mg throughout surgery
What does hypothermia mean for muscle relaxants?
they won’t metabolize muscle relaxants as well while they’re hypothermic
4 advantages of opioids?
no myocardial depression, diminish stress response, bradycardia, decreases SVR (fent wont)
5 disadvantages of opioids?
no myocardial depression, chest wall rigidity, apnea, decreases SVR, long duration at higher doses
Does fentanyl or sufentanil release histamine?
no
What is the fentanyl dose for balanced technique?
10-25 mcg/kg
What is the fentanyl dose when used as a sole agent?
50-100 mcg/kg
Is sufenta more or less potent than fentanyl?
more
How can you more easily control the dosing of sufenta?
dilute it
What is the balanced dose of sufenta?
1-5 mcg/kg
What is the sole agent dose of sufenta?
10-30 mcg/kg
6 characteristics of thiopental?
ok if EF is good, good if increased ICP, brain protective, depresses myocardium, and decreases venous return, reflex tachycardia
6 characteristics of propofol?
decreases N/V, short duration, less reflex tachycardia, post-op fast track, depresses myocardium, apnea longer
5 characteristics of etomidate?
rapid on and off, HD stability, stable renal/hepatic perfusion, myoclonus, adrenal suppression
6 characteristics of ketamine?
increases SVR, increases filling pressures, increases contractility, increases heart rate, depresses myocardium, supports BP via catecholamines
4 characteristics of benzos?
prevents recall, potent amnestic, decreases BP, reflex tachycardia
Big disadvantage of inhalational anesthetics as far as the heart is concerned?
dose related depression in contractility
3 characteristics of isoflurane?
less myocardial depression, coronary vaodilator, ?coronary steal?
2 things to keep in mind about sevoflurane?
less airway reactivity, theoretical renal considerations
2 things to keep in mind about desflurane?
fast-track agent, airway problems
3 things to keep in mind about halothane?
only useful for tetralogy of fallot, maintains SVR and relaxes RV infundibulum, improves pulmonary blood flow
What is coronary steal?
complete blockage of one coronary artery and partial blockage of another. in normal situations the blocked artery gets collateral flow. however, coronary steal is a theory that with isoflurane, the vasodilation decreases the MAP and flow going in to collateral flow is backfilling for the blocked artery which is not good and the patient becomes ischemic
What do you want to do to prevent coronary steal?
keep MAP up
6 characteristics of pancuronium?
vagolytic, sympathomimetic, rapid onset, long duration, no histamine, inexpensive
4 characteristics of vecuronium?
stable HD, intermediate duration, no histamine, inexpensive
5 characteristics of rocuronium?
faster onset, slightly vagolytic, intermediate duration (shorter than vec), no histamine, more expensive
Drug of choice in patient with renal failure?
cisatracurium
4 characteristics of cisatracurium?
Hoffman elimination, intermediate duration, no histamine, more expensive
6 characteristics of succinylcholine?
rapid onset, short duration, hyperkalemia, myalgia, increased gastric pressure, histamine release followed by decreased BP
3 situations commonly encountered on induction for open heart surgery?
hypotension, HTN/tachycardia, cardiac arrest
Treatment for HTN/tachycardia on induction in open heart patients?
b-blockers or nitro, esmolol if tachy
Antibiotics that you give for open heart surgery?
if >100 kg 1.5 g Vanc 2 hours prior to incision and RUN SLOWLY on the pump, zinacef 1.5 g 1 hour prior to incision
What is amicar/aminocaproic acid? How does it work?
antifibrinolytic that is a lysine analog that binds to the lysine-binding sites on plasmin and plasminogen, thus inhibiting fibrin lysis. has some effect in preventing platelet disaggregation
What is the dose of amicar?
5 g load over 30 min, then 1 g/h for duration of case
Why is aprotenin currently off the market?
2 fold increase in renal failure, 55% increase in MI rates, 181% increased risk of stroke
Describe positioning for open heart surgery?
supine (duh) with arms tucked, gel pads to elbows, towels around hands, sleds (to prevent tired residents from leaning on arms), bair hugger must go under patient and must make sure when you tuck the arms that you don’t cut off the airflow to the bair hugger
What’s the butt check for the a line?
lean butt on a line arm to make sure it doesn’t dampen since it is likely that surgeon will lean on it during surgery
Which side should the ETT be on and why?
left so RIJ for CL placement
During induction and after you secure the ETT on the left side, what are the next 4 things you should do?
NG in and out, TEE in to stay, be certain you can reach foley bag, ether screen positioning (put towards head of bed, high, towards end of rail on table and tip back quite a bit, and make sure that if someone leans on it it won’t move)
When comparing a PAC and CVC, what is one additional risk of a PAC?
rupture of pulmonary artery
What are the RA, RV, PA, and PAOP landmarks for a PAC?
RA= 25 cm, RV=35 cm, PA= 45 cm, PAOP= 50 cm
If you’re in to 60 cm w the PAC, what is happening?
you’re in too far and there is probably a kink somewhere, deflate the balloon and withdraw the catheter and readvance
When do you know you’re in the RV outflow tract?
trace starts to change on upstroke of ventilation. the PA is right after RV outflow tract
Normal mixed venous O2 sat according to this lecture?
67-77%
What does mixed venous O2 sat reflect?
reserves left at the end of circulation; it is the oxygen content of mixed venous blood
At what value of SvO2 do you expect loss of consciousness? And what value do you expect cellular death?
LOC
You would expect an SvO2 of less than ____ if lactic acidosis had been left untreated?
50%
As far as SVO2, what is more important when monitoring- the actual number or a trend?
trend
Why does SVO2 rise with nitroprusside toxicity?
there is no O2 consumption going on because of poisoning by cyanide ions
What is the equation to calculate SVO2?
SaO2 - [VO2/(CO x 1.36 x Hgb)]
What is VO2?
oxygen consumption
What is SaO2?
arterial oxygen saturation
What are some causes of increased SVO2?
high CO (sepsis), artifact (wedged), anesthesia, paralysis, hypothermia, cyanide poisoning
What are some causes of decreased SVO2?
increased O2 consumption, shivering, fever, stress
What labs should you get before incision?
baseline glucose, ABG, ACT
Is hypothermia due to drift okay? Why?
yes; it decreases MVO2
