Cardiac Flashcards
Standard way to eval for cardiac risk?
Want to follow AHA/ACC 2014 guidelines:
1) Do thorough H&P (angina, SOB, peripheral edema/elevated JVP)
2) Assess pt’s risk of undergoing a MACE (major adverse cardiac event) using RCRI
3) If elevated, determine METS. If low or N/A, determine with surgeon if possibility of intervention to optimize or not (CABG, PCI, or surgeon’s willingness to operate?)
4) If results of stress test would alter management, order it
RCRI factors (6) and how many in order to be considered to have an elevated risk for MACE?
1) Insulin dep DM
2) Hx of ischemic heart disease
3) Hx of compensated/prior HF
4) Hx of cerebral vascular disease
5) Renal insufficiency
6) Intra-peritoneal, intra-thoracic, or suprainguinal vascular surgery
During a code, what are some things you can evaluate for using echo?
- Assess for any RWMAs
- PE
- cardiac tamponade
- HF (R and L heart contractility)
- Acute dissecting aneurysm
Two types of pharmacological stress tests?
- Dobutamine stress test
- Adenosine Thallium stress test
Good way of explaining why regional anesthesia is good for pt w/cardiac disease?
- better HD stability
- avoid myocardial depression ass w/GA
- avoid need for tracheal intubation + associated symp response
- reduce need for vasopressor administration w/associated inc in afterload
- continues neuro assessment of pt since awake (important in certain cases, like CEA)
Good way of explaining what preop anxiety can lead to (detrimental effects on heart)
- inc in HR, SVR, and myocardial O2 consumption
What is myocardial preconditioning?
- exposure to certain drugs protects myocardium against subsequent myocardial ischemia and reperfusion injury (mech not well defined, prob d/t their dose-dep dec in myocardial contractility and loading conditions)
- 0.25 MAC volatile (iso, sevo, des all w/similar efficacy) may limit infarct size, prevent dysrhythmias, preserve myocardial fxn
What to do if your pt starts developing ST dep?
Attempt to optimize myocardial O2 supply/demand by:
- ventilating w/100% FiO2
- correcting any anemia
- treating tachycardia
- possibly dec afterload (carefully, since dec SVR risks cerebral perfusion): NTG has short DOA and benefits on coronary circulation
How to answer:
“Patient’s blood pressure decreases to ___ (82/60 or whatever) - what do you do?
1) recheck BP
2) ensure adequate ventilation/oxygenation
3) look at the EKG for signs of ischemia or arrhythmia
4) look at surgical field for excessive bleeding
5) place in Tburg
6) give fluid bolus
7) consider vasoconstrictor administration
Two p waves for every QRS in pt w/previous heart transplant - what’s going on?
Unlikely to be heart block, instead likely native atrial tissue (sinus node) creating an impulse that is not conducted over the anastomotic line
Would you perform a neuraxial technique for TKA in pt with transplanted heart? Why/why not?
- Wouldn’t do a spinal bc rapid drop in preload and heart can’t compensate with inc HR
- Would do a slow epidural instead if issues with doing a GA (difficult airway, etc)
Any differences in monitors for a GA in pt w/previous heart transplant undergoing noncardiac surgery?
- art line
- +/- central line (d/t reliance on preload rather than HR, better able to assess fluid status)
- foley (again, fluid status)
- peripheral nerve monitor since immunosuppressant meds can affect NMB
- immunosuppressants inc infx risk, so strict aseptic techniques for all invasive monitor placement
Explain induction for pt w/hx of severe asthma, MP III, and heart transplant
- B2 agonist
- difficult airway equipment available
- isoproterenol available (direct beta to inc HR PRN)
- ketamine and inhalational induction
Would you administer glycopyrrolate when giving neostigmine to a heart transplant patient to reverse them?
- yes, because these pts have been shown to recover some of their parasymp innervation back 6 mo post tx, so don’t want to risk it
- also want to counteract the noncardiac effects of a cholinesterase inhibitors agent like neostigmine (salivation, bronchospasm)
Other possible organ issues 2/2 hx of cardiac transplant?
- renal dysfxn 2/2 cyclosporine
- gastritis 2/2 chronic steroids
- immunosuppression and infx
Risk factors for late stent thrombosis s/p DES?
- cessation of DAPT!! #1 most significant factor (should wait 6 mo)
- multiple, small vessel, bifurcation, and ostial lesions
- long or overlapping or malappositioned stents
- dec LVEF
- hypercoag states (preg, malignancy, DM)
- DM
- renal insuff
- major cardiac events w/in 30d of PCI
- operation (inc catecholamines, inc pltl aggregability, dec fibrinolysis)
How long before proceeding with elective surgery s/p DES? BMS?
DES:
- 6 mo for completely elective
- 3 mo (w/newer generation DESs) if delay of surgery risk > expected risk of stent thrombosis
- if do continue w/surgery w/in these time frames, should continue DAPT, monitor for signs of stent thrombosis, and confirm availability of interventional cardiologist
BMS:
- 1 mo for elective
How is “bridging tx” is employed in a situation where the bleeding risk is too high if DAPT is continued?
What to do if have persistent PVCs?
- how frequent? >3/min, polymorphic, runs of >2, R-on-T = inc rate of VT/VF
- ID any hypoxemia, MI, hypoK, hypoMg, irritation from CVC/PAC
- d/c any pro-dysrhythmic/QT prolonging drugs
- get defib in room
- if became unstable: overdrive pacing or meds (amio, procainamide, BB, sotalol)
- if VT: stable (amio), unstable (shock)
Ddx for hypoTN (trauma)
- spinal shock (loss of cardioaccelerator fibers T1-T4)
- anesthetic OD
- PE (long bone fx, etc)
- PTX (rib fxs, CVC)
- cardiac tamponade
- occult bleeding (abd, thorax, long bone fx)
- blunting of RAS system by lisinopril
In pt w/WPW and asthma, do you admin B agonist?
- No, bc at risk for re-entrant tachy, pre-excited afib, vfib
- Obviously at inc risk of hypoxia and bronchospasm, so have B agonist and epi readily available to be able to admin if absolutely necessary
What to do and administer to patient w/asthma and WPW who develops narrow complex tachy?
- likely re-entrant tachy (SVT)
- wouldn’t choose BB here d/t asthma
- have surgeon stop stimulation
- give 100% FiO2 and call for EKG
- apply patches for cardioversion in case pt becomes HD unstable
- give 6mg adenosine to slow AV nodal conduction, consider CCB or amio
What is the periop d/c of BB associated with? What about starting BB if not already taking any?
Inc risk of MI and chest pain
ACC/AHA guidelines: class I rec to continue BB if already taking them
High-dose, untitrated BB is a/w/ inc incidence of hypoTN, brady, stroke, overall mortality. Best to initiate 2-7d prior to surgery and titrate to HR 60-80
For thoracic aneurysm repair, what is the point of the lumbar drain?
- would allow for passive drainage of CSF to allow for better preservation of spinal cord perfusion. PP = distal aortic P - CSF (or CVP, whichever is highest)
- spinal cord usually controlled by autoreg, but this can be impaired, + clamp induced increases in CSF P —> careful drainage is reasonable strategy
- be careful if they’re on anticoagulation/antipltlts! D/c for however long before and after insertion/removal
What is a word for the antiplatelets like clopidogrel, prasugrel, ticlopidine, etc?
Thienopyridines
What are the ASRA guidelines for neuraxial procedure if patient is on heparin and GP IIb/IIIa inhibitor? How long to wait for each
- platelet aggregation normalizes following d/c of GP IIb/IIIa in 4-8 hrs, and 4-6 hours after IV heparin. So wait 8 hrs before placement
- GP IIb/IIIa inhibitors used for bridging tx when pt who requires thienopyridine tx (clopidogrel, etc) to prevent stent thrombosis must undergo surgical procedure where risk of bleeding makes continuation of long acting platelet inhibitor unacceptable
How do you manage epidural placement/removal if have to go onto CBP? Like in thoracic aneurysm repair etc
- ensure preop anticoags stopped for appropriate length of time (e.g. 8 hours for GP II/III inhibitors, heparin IV)
- delay systemic heparinization for 60min after epidural placement
- use smallest amount of heparin necessary
- monitor carefully for s/s of epidural hematoma
- ensure adequate coagulation at time of catheter removal
Details about the art line for thoracic aneurysm repair?
- Need two: one in UE, one in LE (will be doing partial bypass on lower body, remember convo w/C, you’ll essentially need to maintain the correct MAP through the bypass circuit so as to not steal too much flow from the upper body and not allow the native heart to pump adequately
- In their answer, they say to have the UE one on the R arm since clamping of the L subclavian might be necessary (if aneurysm involves proximal descending aorta, clamp may be placed proximally)
What’s the deal with heart transplant patients and their denervation?
- lack of autonomic innervation –> can’t respond to acute hypoTN by inc HR, so instead relies on adequate preload to maintain CO
- response to circulating cats is normal though
- HR response to normal resp variations, carotid sinus massage, valsalva, oculocardiac reflex ==> all absent
- absent vagal influences cause relatively high resting HR (90-120)
Differences in anesthetic goals for patients with MR vs MR 2/2 MVP?
In essence, you want to avoid everything that can cause more ventricular emptying –> worsens MVP –> inc MR
Brief summary of Crawford classifications for thoracoabd aneurysms?
What is an endoleak?
- failure to completely isolate aneurysmal sac from arterial blood flow
- particularly bad bc potential for pressurization of sac (endotension) –> aneurysmal enlargement –> rupture
- five types described (see pic)
What are the ACC/AHA guidelines for getting preop TTE?
