Cardiac Surgical Patient Flashcards
Why is there perioperative risks?
- Major hemodynamic stress
- Changes in cholinergic activity
- Changes in catecholamine activity
- Body temperature fluctuations
- Fluid shifts
- Pain
Risks of anesthesia?
- Decrease systemic vascular resistance
- Decrease Stroke Volume
What does induction of general anesthesia do to your systemic arterial pressure?
- Lowers by 20-30 %
- Anesthetic agents lower cardiac output by 15%
What does tracheal intubation to do your blood pressure?
-Increases by 20-30mmHg
Many anesthetic lower CO by what percent?
10-15%
In addition to identifying the presence of pre-existing manifested heart disease it is essential to define disease _________, _________, and _______ _________.
Severity, stability, and prior therapy
What is the main factor that can help you determine cardiac risk?
Functional Capacity
What type of surgical procedures are considered higher risk?
Vascular procedures and prolonged, complicated thoracic, abdomen, and head and neck procedures
The presence of _______ maybe also place a patient at a higher perioperative risk
Anemia
In addition to CAD and CHF, a history of what co-morbidities increases perioperative cardiac morbidity?
Cerebrovascular Disease, preop elevated creatinine greater than 2mg per deciliter, insulin treatment for DM, and high risk surgery
What are the 4 cornerstones of preoperative cardiac evaluation?
- review of history
- physical examination
- diagnostic tests
- knowledge of the planned surgical procedure
Evaluation of Cardiac Risk
See Slide 13
What is included in evaluation of cardiac risk- valvular heart disease
- Dyspnea, Orthopnea, PND
- Embolic Events
- Hemoptysis
- Heart Failure, Palpitations
What would you look for in the general appearance of the physical exam that would be concerning?
Cyanosis, pallor, dyspnea during conversation or minimal activity, nutritional status, obesity, skeletal deformities, tremor and anxiousness
What is included in a detailed cardiac exam?
- JVD, Pedal edema
- Capillary Refill
- Displaced apical impulse (cardiomegaly)
- S3 Gallop (increased LVEDP)
- S4 (decreases compliance)
- Presence of murmurs
- Pulmonary Edema
What is a MET or metabolic equivalent defined as?
The ratio of a person’s working metabolic rate relative to the resting metabolic rate
T/F: one MET represents the oxygen consumption of a resting adult (3.5ml/kg/min)
True
If patients reduce exertion because of cardiac symptoms but still meet a 4-MET threshold clinicians will under or over estimate risk?
Underestimate
Non cardiac functional limitations (ex: knee or back pain) may falsely over or under estimate cardiac risk?
Overestimate
What range is considered poor, moderate and good for METS.
Poor <4 METS
Moderate 4-7 METS
Good >7-10 METS
Measurements on a treadmill inducing ischemia at low-level exercise (<5 MET) or heart rate <100/min identifies what
A high risk group
The achievement of more than 7 MET (or heart rate >130/min) without ischemia identifies what?
A low-risk group
The presence of abnormalities on ECG such as Q waves and non sinus rhythms have been shown to correlate with that?
Adverse Postoperative Cardiac Events
What can alter an ECG tracing?
- Metabolic
- Electrolyte Disturbances
- Medications
- intracranial disease
- Pulmonary disease
What is considered the gold standard for risk indices?
ACC/AHA
What are considered major disease processes?
- Unstable coronary Syndromes
- Decompensated Heart Failure
- Significatn Arrhythmias
- Severe Valvular Disease
- see slide 26
What are considered intermediate disease processes?
- Mild angina
- History of MI, pathologic Q’s
- Compensated our prior CHF
- Diabetes Mellitus
- Renal Insufficiency(CKD)
What disease processes are considered minor?
- Advances age
- Abnormal ECG (LVH, LBBB, ST-T abnormalities)
- Rhythms other than sinus (AF)
- Low functional capacity
- History of stroke
- Uncontrolled systemic hypertension
High risk surgeries (5% risk of perioperative death or MI) include:
Emergent major surgery, peripheral vascular or aortic surgery, prolonged surgery involving excessive blood loss
Moderate risk surgeries (1-5% risk of perioperative death or MI) include:
Carotid endarterectomy, urologic, ortho, uncomplicated abdominal, head, neck or thoracic operations
Low risk surgeries (<1% risk of perioperative death or MI) include:
Cataract removal, endoscopy, superficial procedure, cosmetic procedures, and breast surgery
Indications for preoperative cardiac testing
- patients with intermediate clinical predictors
- prognostic assessment of patients undergoing initial eval for suspected or proven CAD
- Eval of patients with a change in clinical status
- Eval of adequacy of medical treatment
- Prognostic assessment after acute coronary syndrome
Noninvasive cardiac tests
- Transthoracic ECHO
- Exercise tests and pharmacologic tests
- Exercise stress test
- Dobutamine stress ECHO
- Adenosine stress test
- Ambulatory ECG monitoring
What are some strategies to reduce risks?
- General vs Regional anesthesia
- Temperature Monitoring
- Invasive monitoring: PAC, TEE
- Laparoscopic vs Open
- Endovascular
What are some medical management ways to reduce risk?
- use of beta blockers
- Other anti-ischemic medications
- Lipid lowering agents
Class I: preoperative coronary angiogram/coronary intervention
See slide 40
Evidence based practice parameters: Classes
Class 1: benefits greatly outweigh the risks Class 2a: reasonable to consider Class 2b: may be reasonable to consider Class 3: not indicated Level A: highest level of evidence Level C: lowest level of evidence
