Download Anesthetic implications of cardiovascular disease

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To identify the patients at risk for peri-op cardiac
complications.
To evaluate the severity of underlying ds and if necessary
implement measures to prepare high risk patients for noncardiac surgery with maximum optimisation.
Identification of risk factors
Preparation and plan of anaesthetic management
intraoperatively.
Postoperative management of adverse events (stress on
prevention).
 History
(including risk stratification)
 Examination
 Laboratory investigations
 Cardiac function assessment
 Cardiovascular conditions assoc:
hypertension, ischemic heart disease, heart
failure, valvular heart disease, arrythmias,
peripheral vascular disease, pulmonary
arterial hypertension.
 Detailed
history of cardiovascular co
morbidity (symptoms, duration, past
interventions etc.)
 Other co existing conditions (DM, PVD)
 Medications – history, current medication,
effectiveness.
 History of any aggravating and relieving
factors.
 Asthma, epilepsy, drug allergy, egg allergy,
past surgery- type of anesthesia, any event,
post op complication.
 Loose tooth, denture.
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Vital parametes : pulse rate, volume, nature, bruit,
peripheral pulses. BP, in all limbs in PVD.
GPE – pallor, cyanosis, JVP, Pedal edema.
CVS examination- displaced apical impulse, parasternal
heave, thrill, palpable P2, S3 , S4, murmurs.
Resp examination – b/l air entry, added sounds, pulmonary
edema, pleural effusion.
Abd examination – signs of HF
Airway assessment.
Peripheral venous access
Spine examination.
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CHG – Hb, TLC,DLC, Hct, platelet count. (anemia adversely
affects cardiac outcome; Hb >10 gm% a/w less morbidity)
FBS
LFT,RFT with electrolytes (BUN and Cr esp in HTN, diuretics)
URINE-routine and microscopy.
CULTURES in I/E.
CXR (Cardiomegaly, Signs of LV dysfn- incrsd pul vascular
markings, pul edema, pleural effusion, Pacemaker, ICD can be
seen, evidence of PAH)
ECG (baseline, within last 3 months if no new symptoms, 12
lead ECG, CAD- in old MI ,inverted t-wave, prominent and
deep Q-wave, dysrhythmias, Conduction defects, Digitalis
toxicity, dyselectrolytemia).
Coagulation profile (esp in patients of valvular disease on
anticoagulants).
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recommended for patients with at least one clinical risk
factor for vascular surgical procedures; for patients with
known CHF, peripheral arterial disease, or
cerebrovascular disease undergoing intermediate-risk
surgical procedures.
reasonable in persons with no clinical risk factors for
vascular surgical procedures
may be reasonable in patients with at least one clinical
risk factor for intermediate-risk operative procedures
not indicated for asymptomatic persons undergoing lowrisk surgical procedures.
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Presence ,severity & reversibility of CAD
1) risk factors
2) active cardiac condition
3) previous MI, prior cardiac evaluation
4) past interventions – CABG,PTCA
5) functional capacity (NYHA)
6) co-morbid conditions
7) dysrhythmias
 Physical
status classification(ASA)
 Cardiac risk index ( Goldman)
 Revised cardiac risk index ( Lee’s )
 Eagle criteria
 ACC/AHA guidelines 2007
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Third heart sound (S3): 11 pts
Elevated jugulovenous pressure: 11 pts
Myocardial infarction in past 6 months: 10 pts
ECG: premature arterial contractions or any rhythm other
than sinus: 7 pts
ECG shows >5 premature ventricular contractions per
minute: 7 pts
Age >70 years: 5 pts
Emergency procedure: 4 pts
Intra-thoracic, intra-abdominal or aortic surgery: 3 pts
Poor general status, metabolic or bedridden: 3 pts
High risk surgery (intraperitoneal, intrathoracic,
or suprainguinal vascular procedures)
 H/O Ischemic heart disease (any diagnostic
criteria)
 H/O Heart failure
 H/O Cerebro-vascular disease
 Diabetes mellitus req treatment with insulin
 Pre-op S.Cr over 2 mg/dl
Rate of major cardiac complications0 – 0.5 %
1- 1.3%
2 – 4%
>3 – 9 %
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High (>5%)
 - Emergency major operations, particularly in elderly
 - Aortic and major vascular procedures
 - Peripheral vascular procedures
 - Prolonged procedures with large fluid shifts +/- blood loss
Intermediate (<5%)
 - Intraperitoneal / Intrathoracic surgery
 - Carotid endarterectomy - Head and neck surgery
 - Orthopedic surgery - Prostate surgery
Low (<1%)
 - Endoscopic procedures - Superficial procedures
 - Cataract surgery - Breast surgery
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Similar to Goldman's but specifically for evaluating cardiac
risk in vascular surgery patients
" Eagle factors": >70yo, h/o angina, significant Q's, CHF, DM
needing Rx
Risk of perioperative MI:
"Low risk": if 0 factors, risk = 3.1%; no additional pre-op
testing needed
"Intermediate risk: if 1-2 factors, risk = 15%; noninvasive
testing with angio if inducible ischemia.
"High risk: if > 2 factors, risk = 50%; go straight to
angiography.
If angio shows left main disease etc., consider angioplasty
or CABG before planned surgery; if serious lesions not
amenable to either, consider foregoing surgery.
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STEP 1: determine the urgency of the surgery; focus on
perioperative surveillance (serial ECGs, enzymes,
monitoring) and risk reduction.
STEP 2: determine whether the patient has an active
cardiac condition (acute MI, unstable or severe angina,
decompensated heart failure, severe valvular disease,
arrhythmias) which requires postponement. acute MI (in
7 days) considered high risk and elective surgeries
postponed. A recent MI (within the past 30 days) with
evidence of myocardium at risk (generally based on
persistent symptoms or results of stress testing), is also
a high-risk condition. However, a recent (8 to 30 days
previously) MI without evidence of myocardium at risk
is considered an active cardiac condition and equivalent
to any history of CAD.
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STEP 3: determination of the surgical risk or severity.
Patients without active cardiac conditions who are
undergoing low-risk surgery can proceed to surgery
without further cardiac testing.
STEP 4: assesses the patient's functional capacity.
Asymptomatic patients who are highly functional can
proceed to surgery.
STEP 5: determination for patients with poor or
indeterminate functional capacity. The presence and
number of clinical predictors drive the
recommendations for and probable benefit of further
cardiac testing. Patients with no clinical predictors
proceed to surgery.
MAJOR- acute or recent MI, UA, decompensated
CCF, significant arrythmias ,severe valvular heart
disease.
 INTERMEDIATE- mild Angina ,old MI(more than 1
mnth), insulin dependent diabetes, compensated
CCF, pre-op creatinine >2mg%
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 MINOR- abnormal ECG, cardiac rhythm
abnormality, history of stroke, uncontrolled HTN,
low functional capacity
Resting & ambulatory ECG
 Exercise stress testing
 Echocardiography
 Pharmacologic stress testing
Dipyridamole/adenosine thallium scintigraphy
Dobutamine echocardiography
 Coronary angiography
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RESTING ECHO: to detect presence &
significance of valvular heart ds ,to detect CHD,
LVEF, chamber enlargement & hypertrophy
 RWMA – types & location: the assessment of
resting LV fxn not routinely recommended for
preop screening.
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 Predictive
value
 LVEF <35% leads to postop CHF
 No consistent correlation with postop
ischemia
 Indicated in Poorly controlled CHF, Unknown
systolic or diastolic function in valvular heart
ds, long standing uncontrolled HTN.
STRESS TESTING: Exercise stress alone (usually Bruce
protocol),Exercise / pharmacological stress with nuclear
myocardial perfusion imaging (MPI), stress echo
(Pharmacologic or exercise).
 Exercise stress echo:
 INDICATIONS- prior non diagnostic or if likelihood of false
positive ECG stress test, ECG abnormalities making
interpretation of ECG stress testing difficult, for prognostic
information post MI, to determine success of intervention .
 Images are obtained once pt hs achieved 85% of target HR
(220-age) to see wall motion abn during max workload and
lastly recovery images with in 90 sec of peak HR.
Pharm stress echo: Unable to exercise or Inability to achieve
target heart rate during exercise because of therapy with
High dose beta-blocker or calcium channel blocker
 Dobutamine/dipyridamole/adenosine used to induce cardiac
stress.
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Acute myocardial infarction (within two days)
 Unstable angina pectoris
 Uncontrolled arrhythmias causing symptoms of
hemodynamic compromise
 Symptomatic severe aortic stenosis
 Uncontrolled symptomatic heart failure
 Active endocarditis or acute myocarditis or
pericarditis
 Acute aortic dissection
 Acute pulmonary or systemic embolism
 Acute noncardiac disorders that may affect
exercise performance or may be aggravated by
exercise
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INDICATIONS - Done in Pts having positive stress tests
suggesting significant myocardium at risk.
-To detect or exclude serious CAD i.e. left main or 3 vs ds.
-chronic stable angina pts who are severely symptomatic
despite medical therapy
-Pts with ventricular dysfxn
-In young patients with VHD to rule out assoc. CAD before
cardiac surgery.
-patients being considered for revascularization -Helps to
decide how many bypass grafts should be performed
- for definitive diagnosis of CAD individuals whose
occupations could place others life in danger( pilots)
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Generally patients are on multiple drugs depending on the
cardiovascular condition: antihypertensives, diuretics,
beta blockers, digoxin, vasodilators, anticoagulants.
HYPERTENSION: elective surgery be delayed if BP>180/110 mm
Hg. If severe end organ damage is present, the goal should be to
normalize BP as much as possible before surgery. Effective
lowering of risk may require 6-8 weeks of therapy to allow
regression of vascular and endothelial changes. If surgery can’t be
postponed, the goal is not to decrease chronically increased BP too
rapidly, as too rapid lowering of BP may increase risk of cerebral,
coronary ischemia.
Rule out causes such as coarctation, hyperthyroidism,
pheochromocytoma, or drug use such as cocaine,
amphetamines, anabolic steroids.
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routinely administer all antihypertensive drugs
preoperatively, except ACE inhibitors or angiotensin II
antagonists , which is tailored to the individual patient,
due to risk of intra operative hypotension.
If these drugs are continued, vasopressin is the drug of
choice for refractory hypotension.
the major effect of diuretics after 1 week of therapy is
arteriolar vasodilation and assessment of urine output may
be inaccurate if the diuretic is abruptly discontinued on the
morning of surgery, so some studies advocate continuing
them, rule out and correct dyselectrolytemias.
Beta blockers must be continued in all patients (if on
therapy). No evidence in favour of acute administration of
these drugs though some studies have shown benefit with
low doses.
No role of prophylactic NTG unless ischemia occurs.
Optimal anxiolysis.
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IHD/ CAD: Vasodilation with nitroglycerine, nitroprusside,
prazosin in order to decrease ventricular wall tension. Allaying
fear, anxiety and pain preoperatively are desirable goals in patients
with CAD to prevents sympathetic activation, which affects
myocardial oxygen supply–demand balance. To continue beta
blockers (dosages adjusted to achieve an HR lower than 70
beats/min) statins, antihypertensives should be continued.
PCI performed “to get the patient through surgery”
may not improve perioperative outcome because
cardiac complications may not occur in patients with
stable or asymptomatic coronary stenosis.
elective noncardiac surgery after PCI, with or bare
metal stent placement, should be delayed for 4 to 6
weeks; with drug eluting stent for 1 year.
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Continue aspirin therapy in all patients with a coronary
stent and discontinue clopidogrel for as short an interval as
possible for patients with bare-metal stents in place for
less than 30 days or drug-eluting stents for less than 1 year.
Aspirin (75-150 mg/day) for primary prev: Stop 7 days
before operation as needed.
Secondary prevention: stop if Risk of bleeding in closed space
(intracranial neurosurgery, intra-medullary canal surgery,
posterior eye chamber ophthalmic surgery).
Aspirin+clopidogrel: High-risk situations:<6 weeks after MI,
PCI, BMS, stroke,<12 months after DES,High-risk stents stop
clopidogrel only if above surgery else continue both.
Low risk: Stop clopidogrel, Maintain aspirin.
the risk/benefit ratio of upholding vs withdrawing aspirin
must be evaluated for each case individually; in case of
aspirin upholding, early postoperative re-institution is
important.
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HEART FAILURE: may be systolic, diastolic or both.
Hypertension is a cause of diastolic dysfunction, and LVH
on an ECG should raise suspicion. Ischemic heart disease
is the most common cause of systolic dysfunction.
Decompensated heart failure is considered a high-risk
cardiac condition, and elective surgery should be
postponed . Brain naturetic peptide (BNP),released from
the ventricles of the heart, useful in evaluation. plasma
concentration of BNP correlates with NYHA functional
class.
Digoxin levels should not be routinely measured unless
toxicity under treatment or noncompliance is suspected.
One should determine trough levels of digoxin.
An objective measure of LVEF, ventricular performance,
and diastolic function with echocardiography is helpful.
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VALVULAR HEART DISEASE: Murmurs: D/t turbulent flow across the
defective valve. Note the character, location, intensity, direction of
radiation.Systolic murmurs: AS, PS or MR,TR. Diastolic murmurs: MS, TS
or AR, PR. Dysrhythmias: AF (esp Mitral valve ds.) i.e. with enlarged Lt
atria. Predisposed to thromboembolic phenomenon. benign murmurs
occur with high-outflow states such as hyperthyroidism,
pregnancy, or anemia.
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stenotic lesions progress faster than regurgitant lesions do.
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Regurgitant lesions tolerated better.
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If on anticoagulants target INR<1.5. in case of high risk pts consider
bridging therapy with heparin. Weigh risk vs benefit for regional
anaesthesia (spinal haematoma, stenotic lesions).
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Prophylaxis of Bacterial endocarditis
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Class I—echocardiography is useful in asymptomatic
patients with the following cardiac murmurs: • Diastolic
murmurs • Continuous murmurs • Late systolic murmurs
• Murmurs associated with ejection clicks • Murmurs
that radiate to the neck or back • Grade 3 or louder
systolic murmurs
Class IIa—in asymptomatic patients with: • Murmurs
associated with other abnormal physical findings on
cardiac examination • Murmurs associated with an
abnormal ECG or CXR
Class III—echocardiography is not useful in asymptomatic
patients with the following murmurs: • Grade 2 or softer
midsystolic murmurs considered innocent or functional
by an experienced observer.
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Assessment of Prosthetic Valve function:
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Dysfunction (Change in intensity/ quality of clicks,
new or change in characteristics of murmurs)
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Tranthoracic Echo: To assess ring stability and leaflet
motion
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Transesophageal Echo: Better resolution
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MRI: For prosthetic valve regurg, paravalvular leak
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Cardiac Catheterisation: For Transvalvular pressure
gradient, Effective valve area
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ARRYTHMIAS: Bradyarrhythmias, especially if profound or
associated with dizziness or syncope, are generally
managed with pacemakers.
Predictors of the need for pacing included previous
symptomatic bradyarrhythmia, a history of transient
complete AV block, and aortic valve disease.
More than five PVCs per minute on preoperative
examination correlates with perioperative cardiac
morbidity. the classic criteria for treating PVCs: the
presence of R-on-T couplets, the occurrence of more than
three PVCs per minute, and multifocality of PVCs, must be
added frequent (>10/hr over a 24-hour period) and
repetitive ventricular beats.
Premature atrial contractions and cardiac rhythm other
than sinus also correlate with perioperative cardiac
morbidity.
Preoperative evaluation focuses on reversible causes such
as hypokalemia, ischemia, acidosis, hypomagnesemia, drug
toxicity, and endocrine dysfunction and their correction.
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ventricular arrhythmias classification:
Benign: isolated ventricular premature beats (VPBs)
without heart disease No need for further evaluation No
risk of sudden cardiac arrest
Potentially lethal: greater than 30 VPBs/hr or nonsustained
ventricular tachycardia with underlying heart disease
Requires cardiology evaluation with possible
echocardiography, stress testing, catheterization, or
electrophysiologic testing Moderately high risk of sudden
cardiac arrest; may benefit from an ICD
Lethal: sustained ventricular tachycardia, ventricular
fibrillation), syncope, or hemodynamic compromise
associated with VPBs with underlying heart disease and
often depressed cardiac function. Requires cardiology
evaluation with possible stress testing, echocardiography,
catheterization, or electrophysiologic testing High risk of
sudden cardiac arrest; likely to benefit from an ICD.
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Adequate premedication: avoids sympathetic response.
Technique of anesthesia: general vs regional.
Regional avoids airway manipulation but in an unco
operative patient anxiety can stimulate tachycardia and
angina like symptoms. If planned for hypotensive
anaesthesia, better managed with GA.
Monitoring: ECG remains the standard to monitor for
ischemia, a display monitor that allows viewing of two
ECG leads simultaneously, usually leads II and V5, along
with automated ST-segment analysis.
NIBP , pulse oximetry essential.
IBP to be weighed as per surgery.
PA catheter, TEE.
Intake/output monitoring
NMJ monitoring
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Most opioids, hypnotics, and volatile anesthetics have
been used successfully in different combinations for
induction and maintenance of anesthesia. Anesthetic
drugs and doses are selected according to two main
considerations, the first being LV function.
patients may require vasopressor or inotropic
pharmacologic support.
observation for normothermia, absence of excessive
bleeding or documented coagulopathy, and acceptable
urine output, blood gases, and hematocrit.
Avoidance of histamine releasing drugs.