Transcript PreopCardiacEval

Preoperative Cardiac
Evaluation
Prepared for KMRH residents in
Anaesthesia July 2013
Kabul
Preoperative Cardiac Evaluation
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Risk assessment – Patient and Surgical
Factors
Pre-operative Interventions to modify risk
Intra-operative Interventions to modify risk
Post Operatively Surveillance
Preoperative Cardiac Evaluation
Risk assessment : Patient Factors
I. Congestive Heart Failure
II. MI within 30 days
III. Severe Cardiac Arrhythmia including heart block
IV. Severe Valvular disease
V. Severe or Unstable angina
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Other - Remote MI, Diabetes, Renal dysfunction,
Poorly managed hypertension, Rhythm other than sinus,
Previous or compensated CHF, stable angina
treated hypertension, LVH or LBBB, advanced age
Preoperative Cardiac Evaluation
Patient Factors
Congestive Heart Failure
MI within 30 days
Severe Cardiac Arrhythmia including heart block
Severe Valvular disease
Severe or Unstable angina
These are severe clinical indicators
and patients should be evaluated
and optimized preoperatively
Preoperative Cardiac Evaluation
Patient Factors
Other - Remote MI, Diabetes, Renal dysfunction, Poorly
managed hypertension, Rhythm other than sinus,
Previous or compensated CHF, stable angina
These are intermediate clinical indicators
that may or may not need further evaluation
depending on their functional capacity and
nature of surgery.
Preoperative Cardiac Evaluation
Patient Factors
• Functional capacity – is the patient able to :
Class I – Angina only during strenuous or
prolonged physical activity
8-10 METS
Class II – Slight limitation, with angina only
during vigorous physical activity
6-8 METS
Class III –Symptoms with everyday living
activities, i.e., moderate limitation
4-6 METS
Class IV – Inability to perform any activity
without angina or angina at rest,
i.e.,severe limitation
< 4 METS
Cardiac Risks of Noncardiac Surgery
Surgical Factors
Cardiac stress is inherent to surgery
Anaesthetic technique, drugs, pain, and nature of the
Surgery all effect :
1. The stress response and catecholamines – increase HR and BP
2. Fluctuations in HR, BP, intravascular volume, oxygenanation,
and oxygen transport
These factors will cause imbalance in myocardial O2 supply and
demand
Cardiac Risks of Non-cardiac Surgery
Myocardial Oxygen Supply and Demand
increased HR
decreased HR
increased Systolic BP
increased wall tension
increases chamber pressure
adequate coronary circulation
increased Diastoloic BP
reduced wall tension
decreased chamber pressure
inadequate coronaries
adequate hemoglobin
Supply
Supply
Surgery-specific risks
• High risk (>5% cardiac risk)
– Emergency major operations
• Especially in the elderly
– Aortic or major vascular surgery
– Extensive operations with large volume shifts
or blood loss.
Surgery-specific risks
• Intermediate risk (<5% cardiac risk)
– Intraperitoneal and intrathoracic
– Carotid endarterectomy
– Head and neck
– Orthopedic
– Prostate
Surgery-specific risks
• Low risk surgeries (<1% cardiac risk)
– Endoscopic procedures
– Superficial biopsies
– Cataracts
– Breast surgery
Assessing the situation
• Determine the urgency for surgery
– Emergency Surgery – few options – do the best you can
• Options to consider (as a team)
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Postpone or cancel
Modify the surgical procedure
Delay case (for further testing or patient optimization)
Perioperative medical therapy
Perioperative monitoring
Modification of the location of care
Pre-operative Interventions to Modify Risk
Investigations
• EKG – suitable for most patients over 40 with risk factors
• CXR - if any concern from history or physical examination
• Bloodwork – if significant co-morbidities or chance of significant
blood loss
• Consultation – changing nature of symptoms ( eg worsening
angina ) or concern regarding valvular integrity or
ventricular function
– Testing may include echocardiography or cardiac stress testing
– Medications may be adviseable – B blockers, statins, ASA, others
– Invasive intervention should be based on symptoms, not surgery
Intra-operative Interventions to Modify Risk
• Consider :
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Anaesthetic Technique
Intra operative Monitoring
Choice of Drugs
Post operative analgesia
Post operative care
Intra-operative Interventions to Modify Risk:
Anaesthetic Technique
• Regional Anaesthesia –
– Minimizes the hormonal stress response
– Spinal/Epidural techniques require consideration of
hemodynamic changes
– Never been shown superior or safer to GA
– Some benefit to graft patency for peripheral vascular
surgery
Intra-operative Interventions to Modify Risk:
Choice of Drugs
Optimization of myocardial O2 supply/demand is
the goal !!!
• B blockers
pre or intra operatively may reduce incidence of
adverse cardiac events , may increase risk of cerebrovascular events
• All volatiles (except N2O)
are vasodilators and reduce
contractility – so they may reduce demand, but also reduce supply !
Some ( sevoflurane ) may have intrinsic cardio-protective effects
• Vasopressors
alpha agents ( neosynephrine ) may help increase
coronary perfusion pressure and may be useful in conjunction with
B blockers
Intra-operative Interventions to Modify Risk
Choice of Drugs
• Ketamine increases HR and contractility but may minimize post
induction hypotension – consider combining it with midazolam to
reduce unwanted effects
• NTG enhances coronary perfusion but reduces BP and filling
pressure
• ACE inhibitors and Angiotensin receptor blockers
Beware as they may cause profound post induction hypotension
unresponsive to sympathomimetics – may require small dose
vasopressin (0.4 U)
• Post op Analgesia will reduce the stress response if adequate.
Consider multimodal approach including neuraxial opioids ( if
appropriate monitoring available )
Intra-operative Interventions to Modify Risk:
Monitoring
• Invasive monitoring may assist in guiding fluid
management, provide early warning to hemodynamic changes, and
allow blood analysis
• EKG additional leads ( 5 lead ) may allow detection of up to 70 %
of ischemic events
Post Operative Surveillance
• Post operative cardiac events
– peak at 48 hrs post op
– Myocardial infarctions are often silent with 50%
mortality
– CHF as a result of remobilization of intra-operative
fluids
– Consider intermediate care area for high risk patients
Preoperative Evaluation Algorithm
Putting it all together
Preoperative Evaluation Algorithm
Putting it all together
• For patients with major clinical predictors
undergoing non-emergent noncardiac surgery,
consider delaying the surgery.
– Medical management
– Medical Risk factor modification
– Consider invasive/non-invasive testing
Preoperative Evaluation Algorithm
Putting it all together
• For patients with intermediate clinical predictors,
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evaluate functional status.
Moderate to good functional status (>4 mets)
promps us to look at the procedure itself.
Low functional status (<4 METs) may merit
further testing.
Preoperative Evaluation Algorithm
Putting it all together
• For patients without intermediate clinical
predictors, moderate to good functional status
indicates lowest cardiac risk for all procedures
• Poor functional status should always prompt us
to evaluate the surgical procedure and consider
further testing
Preoperative evaluation algorithm
• Consider noninvasive testing if two or
more are present:
– Intermediate clinical predictors
– Poor functional capacity
– High surgical risk procedure
Therapeutic Preoperative Interventions
at KMRH
• Invasive options available ? ( PCTA, stents, CABG ) for
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severe symptoms
Medical optimization
Stress testing, Echocardiography may direct you to
modify your anaesthetic plans
Thank You