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Flashcards in Cardiac- Coexisting review Deck (44)
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1

Pharmacologic Management for CAD pts? Anesthesia implications of normal pharmacologic mgmt?

Get good H&P- confirm current med management

  • Beta blockers
    • reduce contractility and HR
    • Make sure they're still taking
  • CCB
    • dilate coronary arteries
    • reduce contractiliy
    • reduce afterload
  • ACE inhibitors
    • imporve contractility by afterload reduction
    • 1st line for HTN and DM
    • Can cause intraop HoTN- d/c 24 hours before
  • Nitrates- 
    • dilate coronary arteries and collateral blood vessels
    • decrease peripheral vascular resistance (decreases afterload)
    • vendodilation (decreases preload)
  • Antiplt drug
    • reduce potential for thrombosis
    • consider INR and ability to perform regional

2

Periop MI risk?

  • Risk of periop death d/t cardiac cause is <1% ingeneral population
  • Most periop MIs occurs in frst 24-48 hours after surgery
    • d/t pain, stress, no anesthesia
    • don't set them up for failure- use appropriate adjuncts

3

What time shoudl you wait for elective surgery  after angioplasty without stent, BMS placement, CABG, Drug-eleuting stent placement?

  • Angioplasty without stenting- 2-4 weeks wait
  • Bare metal stent placement- wait at least 30 days; 12 weeks preferred!
    • 3 months ideal
  • CABG- wait 6 weeks; 12 weeks preferred
    • frequently CABG done before elective sx
  • Drug eluting stent placement - at least 12 months
    • drug eluting stnet has antineoplastic/abx coverage that dissolves in few weeks--> month, prevent rethrombose/PLT aggregation

4

What causes decreased O2 supply?

  • Tachycardia (decrase diastolic time)
    • treat underlying cause to treat tachycardia! (pain, hypovolemic, anemic, etc)
  • hypotension- decrease perfusion pressure to heart
  • vasoconstriciton- avoid phenylephrine
  • O2 carrying capacity
    • acid/base
    • anemia- replace blood with blood!
    • hypoxia FIO2 >70%
  • Viscosity- dry, more resistance in vessel, decrease supply
  • Arterial patency- can't control, underlying condition
  • coronary spasm- avoid by reducing stress by preemptic analgesia
    • esp in areas with atherosclerosis. avoid drugs that cause coronary spasm and use drugs like CCB to help increase supply by reducing vasospasm

5

What are factors that increase O2 demand to heart?

  • Tachycardia (this one is also on decreased supply list)
  • Increase Contractiilty- b blockers
  • increased preload- normal volemic patient
  • increased afterlaod
  • shivering- increase metabolic demand
    • keep pt warm
  • hyperglycemia- tight control
    • manage SNS to prevent hyperglycemia
  • HTN- d/t pain
    • treat pain!  manage BP!

6

Goal of managing O2 supply and demand to heart?

Prevent tachycardia and treat immediately because it's the only one that affects both supply and demand negatively

7

What is first step to decide if CAD pt can proceed to sx?

  • Determine if emergent or urgent:
    • optimiize medical management/proceed to surgery
  • If Elective:
    • unstable CAD (major clinical risk factors and/or change in cardiac condition
      • cardiology consultation
    • Stable - next slide
      • determine exercise tolerance, see next slide for further info

8

Pt with stable CAD is having elective sx, what are steps to determine if further testing necessary?

  • Determine exercise tolerance
  • High or intermed risk sx and moderate to minor clinical risk factors
  • if prior revascularization
    • cabg
      • < 5 yr, no change in medical condition
        • no need for stress test, proceed to sx
    • PCI
      • BMS > 6 wk- minimal antiplatleet therapy; no change
        • no need stress test, proceed to sx
    • DES <12 MO AND dual antiplt therapy
      • consult cardiology to blaance risk of thrombosis and/or bleeding
  • If no prior revascularization
    • statify risk further (see next slide)

9

How do you determine If stable CAD with no prior revascularization can proceed to sx?

  • If high or intermediate risk sx or moderate clinical risk factors with no prior revascularization
    • stable CAD (medically optimized or good exercise tolerance)
      • no need to stress test
      • proceed to sx
    • unable to assess CAD or decreased exercside tolerance
      • noninvasive testin (stress test)
        • if positive--> cardiac cath
        • if negative--> proceed to sx
  • If cath shows left mian or equivalent disease--> multidisciplinary approach
    • consider risk of noncardiac sx vs coronary revascularization

Refresh high/intermediate risk sx

  • high risk
    • aortic
    • major vascular sx
    • peripheral vascular sx
  • intermediate
    • intraperitoneal/intrathoracic
    • CEA
    • Head/neck sx
    • orthopedic
    • prostate
  • low
    • endoscopic
    • superficial
    • cataract
    • breast
    • ambulatory

10

Anesthetic mgmt for pt with CAD?

  • Regional
    • tx hypotension with phenylephrine- okay for short periods
    • if bradycardic- use ephedrine
  • General
    • maintain blanace b/w supply and demand
    • do not allow for long periods of hypotention
    • Wake up warm, don't overload with fluids, don't admin too much phenyl and cause increase afterload
  • IMPORTANT TO MAINTAIN BP WITHIN 20% OF PT BASELINE!

11

How do you appropraitely monitor for ischemia in sx?

  • EKG 5- lead at least for angina
  • See table for leads, coronary artery responsible and area of myocardium involved. probably wise to memorzie for test ;-)
  • Dr. E mentioned II. III, V5 being most ideal to monitor for ischemia; these are the areas with increased likelihood for ischemia 
    • ​II, V5 give idea of inferior and anterolateral aspect of heart
      • that side is more muscular, in diastole, doesn't fill as proficiently
  • If specific area has hx ichemia, then minotr that area (ie, circumflex, monitoring I, avL)

12

Induction of patient with CAD?

  • minimal hemodynamic effect (no wide swings in BP!)
    • keep duraiton of laryngoscopy short!
    • minimize response
      • opioids upfront
      • LTA, IV lidocaine, before DL
      • Be efficient, no significant changes to your technique
      • deep, smooth induction
  • Severe cardiac dysfunction
    • etomidate
    • high opioid technique

13

Anesthesia maintenance of pt with CAD?

  • AVOID TACHYCARDIAS!
  • Preload- normal
  • afterload- normal
  • contractility- decrease if LVF is normal- if LVF is reduced, don't mess with it
    • continue BB unless LVF decrease
  • HR- avoid increases
  • Rhythm- NSR is best,
  • MVO2- controlling demand is easier than supply, attenuate sympathetic outflow
    • focus on controlling (decreasing) DEMAND in CAD pt

14

Intraoperative considerations for CAD pt?

All patients undergoing sx will have normal inflammatory response and neuroendocrine stress response. Focus on managing effects of these responses:

  • Inflammatory response
    • hypercoaguable state, plaque rutpures--> thrombus /embolus
      • decreased HCT, hypoxia, vasoconstriciton, decreased BP all contribute to decreased O2 delivery
  • Neuroendocrine response
    • Increase HR increase BP, metabolic changes
    • postop shivering
    • all cause increase O2 demand
  • Decreased O2 delivery and increased O2 demand--> perioperative myocardial injury/infarction which can show up 1-2 days postop!!

To minimzie response intraop:

  • Smooth anesthetic
    • No big fluctuates in HR/BP
    • Admin
      • Opioids
      • intraop tylenol
      • toradol
      • steroids
  • Wake up pain free
  • keep pt warm
  • address blood loss
  • keep well oxygenated!

15

What is definition of hypertensive crisis? Treatment?

Definition: sudden increase in diastolic BP above 130 mmHg

  • due to: activation of RAAS system

TREATMENT:

  • Prompt, but controlled reduction in BP with NTP  (SNP) 0.5-10 ug/kg/min
  • Monitoring UOP (foley) and insertion of intraarterial BP
  • Decrease DBP carefully to 100-110 mmHg over several min to hoursdon't want to drop too quick!
    • Meds:
      • SNP 0.5-10 ug/kg/min
        • DOC, short DOA
      • NTG 5-200 mcg/min
      • Labetalol 40-80 mg q 10 min
        • carefuldon't want to BB heart!! use with arterial dilator like SNP!!
      • Esmolol 50-300 MCG/KG/MIN

16

Quesitons to consider for anesthetic managmenet of HTN patient?

  • Controlle vs uncontrolled HTN?
  • Emergent vs elective sx?
  • Evidence of end-organ damage?
    • angina
    • CHF- problematic d/t increased M/M r/t recent CHF exacerbation
    • CVA- how long ago? what weakness, mentla status?
    • Renal insufficiency- HTN often has renal insuff. Do you expect big fluid volume shifts intraop? may want foley/aline
    • PVD
  • Drug regmien?
    • BB? ACE? ARB? CCB? Did they take them?

17

Management of anesthesia for HTN pt?

  • Preop eval
    • determine adequacy of systemic BP control
    • review pharmacology of drugs being admin to control systemic BP (orthostatic hypotension, bradyacrdia, sedation_
    • Evaluate for evidence End organ damage
      • angina
      • LVH
      • CHF
      • CVA
      • PVD
      • Renal insufficiency
  • Induction
    • anticipate exaggerated systemic BP
    • Limit duraiton DL to avoid HTN
  • Maintenance anesthesia
    • admin VA to blune HTn response
    • monitor for MI
  • Post op
    • anticipate periods of systemic HTN
    • maintain monitoring of end organ function

18

Induction goals for HTN patient?

  • Goal is to minimize SNS stimulationw ith laryngoscopy and intubation
  • attenuate laryngeal reflexes with additional narcotic, increase VA, and lidocine (topical or IV)
  • How?
    • choice of any induction agent is appropriate EXCEPT ketamine (Increase SNS resposne)
    • Lidocaine IV 1-1.5 mg/kg
    • Lidocaine Topical LTA 2-4%
    • opiates
    • VA

19

Maintenance goals in patient with HTN?

  • Goal is to adjust depth of anesthesia to minimize wide shifts in hemodyanmics
    • drop Bp right before DL because it will get dramatically high with DL
  • Be prepared for wide shifts- typical with HTN patients
  • How?
    • Choose IA that is easily adjusted (des, sev)
    • Balanced technique
    • have ephedrine, neosynephrine readily available
    • consider neo gtt if unable to get adequate depth of anesthesia
      • used to living at higher perfusion pressure, keep BP within 20%!!

20

Intraop HTN treatment?

  • Usually d/t pain!
  • incidence is higher in pt with essential HTN
  • treatment:
    • narcotics- if pain is obvious cause
    • IA
    • BB
    • NTG
    • Nipride

21

Treatment of intraop hypotension?

  • Decrease aneshtesia depth
  • fluids
  • sympathomimetics
  • check rhythm--> is it junctional? sometimes pt go into junctional rhythm under anesthesia, unsure exact mechanism
    • maintain normocapnia
    • avoid high concentration of IAs

22

Monitoring of HTN pt?

  • 5 lead EKG
  • A line, CVP, PA cath if extensive sx and venricular dysfunction
  • TEE

23

Emergence of pt with HTN?

  • Controlle emergence
  • minimize sympathetic outflow- every HTN pt will wake up HTN
    • use of narcotics
    • use of lidocaine
    • use of labetalol, esmolol, NTG
    • Deep extubation- if possible

24

Post op HTN treatment?

  • Pain adeuqately controllw?
    • if yes, then HTN treat with
      • hydralazine 2.5-10 mg IV q 10-20 min
      • labetalol 5-20 mg IV q 10 min
      • Nipride 0.5-10 mcg/kg/min

25

Peripheral revascularization for peripheral vascular disease (PVD)

  • Preop:
    • Assess HTN and CAD r/f for PAD
    • Exercise tolearance, pain, claudication with exercise? blood thinners?
  • Intraop:
    • After donor and recipient arteries exposed, tunnel is created and graft is passed
    • graft may be saphenous vein or prothesis
      • own vessel doesn't work that well because probably also atherosclerosed
    • Heparin IV given
      • typically give 3,000-5,000 units
    • Anastomosis are constructed
    • arteriogram to confirm adequate flow- doppler peripherally to confirm adequate flow
      • maintain good BP in these pts!
    • heparin is not likely to be reversed
  • Principle risk during reoncstructive sx is associated with atherosclerosis, especially IHD
    • Pt with PVD has 3-5greater risk of MI, stroke and death!
    • need good exercise tolerance! cleared by cards, stress test, etc
    • have to manage both PVD and CAD!
  • CABG operations are usually performed before sx on peripheral vasculature pt who experience angina and claudication

26

Preferred anesthesia technique for PAD pt?

  • Regional anesthesia: some perceived advantages of regional anesthesia
    1.  increased graft blood flow
      • sympathectectomy below level of regional
    2.  less increase in SVR with cross clamping
    3. Postop pain relief- this also protects SNS outflow
    4. Less activation of coag system
      • decrease plt activation
      • decrease resistance in blood flow
      • preferrable mechanism- consider anticoag/antiplt meds pt on!
  • Regional vs General
    • assess for coag
    • if consideration regional, spinal may be best, to avoid hematoma
    • studies have shown no diff b/w RA and GA in terms of CARDIOPULMONARY complications
      • no diff in MI, death, myocardial ischemia outcomes b/w regional and GA
    • sig difference in complication rate in terms of GRAFT OCCLUSION
      • pt c reigonal do better with graft and graft sx outcome
      • surgeons want regional

27

Anesthetic management of PAD?

  • Consider co morbiidties- biggest CAD
    • CVA, renal, etc?
  • medication hx- impact on anesthetic delivery
    • anticoag--> if increased INR, no regional
  • end organ perfusion and oxygenation-- maintain
    • kidney, brain
  • blood gases- electolyte and pH changes
  • cross clamp- hep admin/record time/reversal?
    •  give heparin (3-5000 max)
    • record time--> heparin peaks 3-5 min after, let surgeon know and they'll cross clamp
    • typically no reversal needed unless higher doses given

28

Peripheral revascularization monitoring?

  • Pt typically present with CAD, DM, HTN
    • tight BG control
  • Preop- make sure pt takes BB and/or other chronic meds
  • intraop a line- useful if labile BP and bypassing large vessels, long case
  • ability to monitor intravascular volume by either CVP and CO or urinary catheter
    • esp is underlying cardiac issues
    • foley with longer cases esp.
  • EBL- keep eye on blood loss. if not clamping adequately, may get quite a bit of bleeding
  • estimated third space
    • wounds can be large OR sometimes small incisions
    • keep eye on third spacing

29

Goal of managmenet of mitral stenosis pt?

Goals (slow tight full) 

  1. Avoid sinus tachycardia or rapid ventiruclar response rate during a fib
    • Stoelting- treat afib c rvr with amiodarone, bb, ccb
  2. avoid marked increases in central blood bolume as associated with over transfusion or head-down position
    • no rapid transfuion or head down
    • dont' want drop or sudden increase in prelaod!
  3. avoid drug induced decreases in SVR
    • use etomidate- any decrease in SVR, hypotension is very difficult to manage, need to treat adequately with phenylephrine
  4. Avoid events such as arterial hypoxemia and/or hypoventilation that may exacerbate pulmonary HTN and evoke RV failure
    • ​will easily back up into pulmonary system!
    • 100% o2 prudent on these pt
    • Stoelting- events that increae pulm HTN=
      • ​Hypoxemia
      • hypercarbia
      • lung hyperinflation
      • increase lung water

30

Induction of anesthesia in pt with Mitral stenosis?

  • Most often accomplished with drugs admin intravenously that are unlikely to increase HR (avoid ketamine) or abruptly decrease SVR (want to maintain tight system)
    • ​ideal- etomidate, high narcotic technique