Preoperative Evaluation Flashcards
one MET is approximately …
the rate of O2 consumption at rest
(3.5 mL/kg/min)
Walking 1 or 2 blocks on level ground is equivalent to how many METs?
3
Climbing 1 flight of stairs, dancing, or bicycling is equivalent to how many METs?
5
Swimming quickly, running or jogging briskly is equivalent to how many METs?
10
In a French prospective cohort study of 1501 patients, the following characteristics were identified as independent predictors of difficult bag-mask ventilation: …
These risk factors are largely consistent with those identified in an American retrospective cohort study of 22,660 patients: …
Other possible risk factors for difficult ventilation include …
- Age more than 55 years
- BMI more than 26 kg/m2
- Absence of teeth
- Presence of a beard
- History of snoring
———————————— - Age 57 years or more
- BMI 30 kg/m2 or greater
- Presence of a beard
- Mallampati classification III or IV
- Severely limited mandibular protrusion
- History of snoring
————————————————— - An increased neck circumference
- Face and neck deformities (i.e., prior surgery, prior radiation, prior trauma, congenital abnormalities)
- Rheumatoid arthritis
- Trisomy 21 (Down syndrome)
- Scleroderma
- Cervical spine disease
- Previous cervical spine surgery
Components of the Airway
Examination
1) Length of upper incisors (concerning if relatively long)
2) Condition of the teeth
3) Relationship of maxillary incisors to mandibular incisors (concerning
if there is prominent overbite)
4) Ability to advance mandibular incisors in front of maxillary incisors
(concerning if unable to do this)
5) Interincisor or intergum (if edentulous) distance (concerning if <
3 cm)
6) Visibility of the uvula (concerning if Mallampati class is 3 or more)
7) Shape of uvula (concerning if highly arched or very narrow)
8) Presence of heavy facial hair
9) Compliance of the mandibular space (concerning if it is stiff, indurated,
occupied by mass, or nonresilient)
10) Thyromental distance (concerning if < 6 cm)
11) Length of the neck
12) Thickness or circumference of the neck
13) Range of motion of the head and neck (concerning if unable to
touch tip of chin to chest or cannot extend neck)
These risks associated with hypertension appear to increase once blood pressure exceeds … mmHg, with each subsequent … mmHg increase in systolic blood pressure and … mm Hg increase in diastolic
blood pressure being associated with a two-fold increase in
the risk of stroke and cardiovascular death.
In the perioperative setting, hypertension is associated with increased
risks of…, but the magnitude of this association is relatively weak (odds
ratio 1.35; 95% confidence limits, 1.17-1.56)
117/75
20
10
postoperative death and myocardial infarction
While preoperative hypertension is associated with an
increased risk of cardiovascular complication, this association
is generally not evident for systolic blood pressure values
less than … mm Hg or diastolic blood pressure values
less than … mm Hg
180
110
There is no compelling data that delaying surgery to optimize blood pressure control will result in improved outcomes
T or F
T
Coronary revascularization— specifically with CABG—improves survival compared to medical therapy (pooled relative risk 0.80,
95% limits 0.70-0.91) in several high-risk IHD states,
namely …
- left main coronary artery stenosis
- triple-vessel coronary artery disease
- two-vessel coronary artery disease with proximal left anterior descending artery stenosis
In patients who meet indications for revascularization, CABG and PCI improves survivel similarly in multivessel disease that is associated with either diabetes mellitus or higher coronary artery lesion complexity
T or F
F
In patients who meet indications for revascularization, CABG improves survival more than PCI in multivessel disease that is associated with either diabetes mellitus or higher coronary artery lesion complexity
Aside from high-risk states (e.g., triple vessel coronary artery disease), PCI has not been shown to convincingly improve survival in stable IHD
T or F
T
Describe the Simplified cardiac evaluation algorithm for noncardiac surgery proposed by the 2014 American Heart Association and American College of Cardiology guidelines
Step 1: Emergency Surgery:
-> Proceed to surgery with clinical risk stratification and perioperative surveillance
Step 2: Active Cardiac Conditions (* acute coronary syndrome; * decompensated heart failure; * significant arrhythmia; * severe valvular disease):
-> Postpone planned surgery until condition is first evaluated and then treated using guidelinedirected
therapy
Step 3: Estimate risk of perioperative death or MI (ACS-NSQIP risk calculator - determine risk using www.riskcalculator.facs.org; Revised Cardiac Risk Index (elevated risk based on score of 2 or more):
- > Proceed to surgery if estimated risk is less than 1%
Step 4: Assess functional capacity:
- > Proceed to surgery if functional capacity is 4 or more metabolic equivalents
Step 5: Assess whether further testing will impact care:
- > Pharmacological stress testing if results would affect decision making or care. If results are abnormal, consider guideline-indicated revascularization strategies
Step 6: Proceed to surgery or consider alternative strategies
* Alternatives included less-invasive or palliative treatment
The 2014 ACC/AHA guidelines define an emergency procedure as one where …; an urgent procedure as one where …; and a time-sensitive procedure as one where …
life or limb would be threatened if surgery did not proceed within 6 hours or less
life or limb would be threatened if surgery did not proceed within 6 to 24 hours
delays exceeding 1 to 6 weeks would adversely affect outcomes (e.g., most oncology surgery).
Simple subjective assessment of functional capacity based on the usual preoperative history accurately estimate true exercise
capacity
T or F
F
Simple subjective assessment of functional capacity based on the usual preoperative history does not accurately estimate true exercise
capacity, and does not accurately predict postoperative cardiovascular complications. Thus, in clinical practice, anesthesiologists should generally use a structured questionnaire, especially the DASI
Correlate the Revised Cardiac Risk Index Score with the Risk of Major Cardiac Events
0 - 0,4%
1 - 1%
2 - 2,4%
3 - 5,4%
A preoperative high-sensitivity troponin T concentration above … is associated with increased risks of death and cardiovascular complications after major noncardiac surgery
14 ng/L
The choice of pharmacologic stress modality is generally immaterial, but there are some exceptions.
For example, since dobutamine uncovers ischemia by increasing contractility, heart rate, and blood pressure, it may not be the best choice in patients with …
While adenosine and dipyridamole rely on their vasodilatory properties and do not depend on a heart rate response, they may exacerbate …
pacemakers, significant bradycardia, aortic aneurysms, cerebral aneurysms, or poorly controlled hypertension
bronchospasm in patients taking theophylline
At present, both American and European guidelines only recommend consideration for revascularization in …, while the CCS guidelines recommend …
patients who meet usual nonoperative indications (e.g., left main coronary artery stenosis, triplevessel coronary artery disease)
against preoperative revascularization in any patient with stable IHD
Whenever possible, surgical procedures should be performed following critical time windows (i.e., … after bare metal stent , or … after DES), aspirin should be continued throughout the perioperative period, and any P2Y12 inhibitor therapy should be restarted …
The importance of continuing aspirin perioperatively is
supported by the substudy of the …
In this subgroup analysis of 470 patients with prior PCI, aspirin … (hazard ratio, 0.50; 95% confidence limits, 0.26-0.95) without any significantly increased bleeding risk.
30 days
3-6 months
as soon as possible after surgery
POISE-2 randomized trial
reduced the risk of death or myocardial infarction
Unfractionated heparin and low-molecular-weight
heparin (LMWH) should be used to “bridge” patients
who have been withdrawn from antiplatelet therapy
T or F
F
Unfractionated heparin and low-molecular-weight
heparin (LMWH) should not be used to “bridge” patients
who have been withdrawn from antiplatelet therapy,
especially since heparin can paradoxically increase platelet aggregation
Decompensated heart failure is a very high-risk condition that warrants postponement of surgery for all except lifesaving emergency procedures.
No consensus exists on how long nonemergent surgery should
be deferred after resolution of acute decompensated heart
failure, although a reasonable approach is to delay elective
procedures (including most time-sensitive procedures) for…, and urgent procedures for …
1 month
24 hours
Loop diuretics (e.g., furosemide) can not be continued on the
day of surgery because of high rates of hypotension during surgery
T or F
F
Loop diuretics (e.g., furosemide) can be continued on the
day of surgery for most procedures since this strategy does
not increase risks of intraoperative hypotension or adverse
cardiac events. The exception is lengthy high-risk procedures with projected significant blood loss or fluid requirements, in which potent diuretics should be held on the
morning of surgery
A Valsalva maneuver … right and left-heart filling, thereby … the intensity of most murmurs except those of …
Standing … preload, and thereby increases the intensity of murmurs of …
decreases
reducing
mitral valve prolapse and hypertrophic cardiomyopathy
decreases
mitral valve prolapse and hypertrophic cardiomyopathy
Having the patient repeatedly perform a hand grip … heart rate and arterial blood pressure, thereby augmenting murmurs of …; conversely, this maneuver decreases murmurs of …
increases
mitral regurgitation and aortic insufficiency
aortic stenosis and hypertrophic cardiomyopathy
Severe aortic stenosis parameters
Transvalvular Jet Velocity (m/s): ≥ 4
Mean Pressure Gradient (mm Hg): ≥ 40
Valve Area (cm2): < 1
Can individuals with asymptomatic severe
aortic stenosis do a noncardiac surgery before valvar surgery?
Moderate to severe aortic stenosis is associated with
increased risk of perioperative cardiovascular complications.
Nonetheless, contemporary studies suggest that noncardiac surgery can be performed with acceptable mortality risks in individuals with asymptomatic severe aortic stenosis
Thus, guidelines support proceeding with major elective noncardiac surgery in patients with asymptomatic severe aortic stenosis, provided that appropriate intraoperative and postoperative hemodynamic monitoring is available
Patients with moderate to severe aortic stenosis
have an increased risk of bleeding from …
The underlying pathophysiology is …
an acquired von Willebrand syndrome, which occurs in 67% to 92% of patients with severe stenosis
mechanical disruption of von Willebrand multimers during turbulent blood flow through the narrowed valve
Prophylaxis for infective endocarditis is not
recommended for patients with severe aortic stenosis
T or F
T
Can individuals with asymptomatic severe
aortic insufficiency do a noncardiac surgery before valvar surgery?
Expert consensus from current guidelines is supportive of patients with asymptomatic severe aortic insufficiency to proceed with major noncardiac surgery accompanied by careful perioperative management, including hemodynamic monitoring, afterload control, and fluid balance
Mitral stenosis involves progressive reduction of this area, with shortness of breath with exertion occurring when the area falls below …, and symptoms at rest occurring once the area falls below …
Severe mitral stenosis is defined by a valve area less than … and is typically associated with a pulmonary artery systolic pressure > 50 mm Hg, and a resting mean transvalvular gradient ≥ 10 mm Hg
2.5 cm2
1.5 cm2
1 cm2
Estenose aortica + sangramento em TGI por lesões angiodisplasicas
Síndrome de Heyde
Cardiac Conditions for Which Endocarditis Prophylaxis Is Recommended
1) Previous infective endocarditis
2) Prosthetic cardiac valves, including transcatheter-implanted prostheses, and homografts
3) Prosthetic material used for cardiac valve repair, such as annulo-plasty rings and chords
4) Unrepaired cyanotic congenital heart disease, including palliative shunts and conduits
5) Repaired congenital heart disease, with residual shunts or valvular regurgitation at the site of or adjacent to the site of a prosthetic patch or prosthetic device
6) Cardiac transplant with valve regurgitation due to a structurally abnormal valve
is a rare cause of sudden cardiac arrest that occurs in the absence of structural heart disease. It is an autosomal dominant disorder that is more common in men, rarely diagnosed in children, and often affects individuals of Asian ethnicity. Patients usually have normal findings on echocardiography, stress testing, and cardiac magnetic resonance imaging (MRI). The most significant clinical manifestations are ventricular arrhythmias, syncope, and sudden death. Patients may also be at increased risk of atrial arrhythmias, especially atrial fibrillation. Is characterized by an ECG with pseudo-RBBB and persistent ST-segment elevation in leads V1 to V3
Brugada syndrome
Drugs used in anesthesia that should be avoided in the Brugada syndrome
Bupivacaine
Procaina
Propofol
Drugs used in anesthesia that may be associated with events in the brugada syndrome (low evidence)
Lidocaine
Ketamine
Tramadol
Effect of a magnet in a cardiovascular implantable electronic device
In general, a magnet suspends antitachyarrhythmia therapy in most ICDs, and switch pacemakers (but not ICDs) to an asynchronous pacing mode
Basic recommendations for procedures in patients with cardiovascular implantable electronic devices
□ Inactivation of ICDs is not absolutely necessary for all procedures
□ Not all pacemakers need to be altered to pace asynchronously in all patients or for all procedures
□ Pacemakers can be reprogrammed or magnets can be used to force pacemakers to pace asynchronously to prevent inhibition
□ ICDs can be reprogrammed or magnets can be used to inhibit ICD arrhythmia detection and tachyarrhythmia functions
□ Magnets can/will not force pacemakers in ICDs to pace asyn- chronously
□ Inactivation of ICDs is recommended for all procedures above the umbilicus involving electrocautery or radiofrequency ablation
□ It is preferable to change to asynchronous pacing in pacemak- er-dependent patients for procedures involving electrocautery or radiofrequency ablation above the umbilicus
selective continuation of aspirin should be considered in which patients?
selective continuation of aspirin should be considered in patients undergoing vascular surgery (to mitigate risks of bypass graft occlusion), as well as those with high-risk IHD, prior PCI, or recent stroke (i.e., previous 9 months)
There are no benefits to using oral corticosteroids preoperatively in an asthmatic patient
T or F
F
Asthma therapy can be supplemented with a short preoperative course of oral corticosteroids (prednisone 20 mg-60 mg daily for 3-5 days) in any newly diagnosed or poorly controlled asthmatic patient
T or F
Measurement of both FEV1 and diffusing capacity for carbon monoxide (DLCO) is recommended in all patients being considered for lung resection surgery
T
How the predicted postoperative FEV1 (PPO FEV1) is calculated? And the PPO DLCO?
The predicted postoperative FEV1 (PPO FEV1) is calculated by multiplying the preoperative FEV1 by the percentage of perfusion to the nonoperative lung or lung region:
PPO FEV1 =Preoperative FEV1 × (Perfusion to nonresected lung / Total perfusion to lungs)
The PPO DLCO is calculated using an analogous equation
for preoperative DLCO
Patients with both PPO FEV1 and PPO DLCO values exceeding 1…% of predicted are considered low-risk and can generally proceed directly to surgery.
If either value is within the range of 2…% of predicted,
3… is recommended.
For individuals with poor performance on these tests (4…), as well as for individuals with either PPO FEV1 or PPO DLCO values less than 5…% predicted, the ACCP guidelines recommend Cardiopulmonary Exercise Testing to measure peak oxygen consumption (VO2 peak)
A preoperative VO2 peak greater than 6… mL/kg/min is consistent with low perioperative risk, 7… mL/kg/min is consistent with moderate risk, and less than 8… mL/kg/min is consistent with high risk
1) 60
2) 30% to 60
3) simple objective exercise testing with a shuttle walk test or
symptom limited stair climbing test
4) i.e., < 400 m on shuttle walk test or < 22 m on stair climbing test
5) 30
6) 20
7) 10 to 20
8) 10
How deal with Upper Respiratory Tract Infections in the preoperative period?
For patients with severe symptoms (e.g., high fever), especially in the presence of other health conditions (e.g., significant asthma, heart disease, immunosuppression), elective surgery should be postponed until 4 weeks after resolution of the infection.
Conversely for mild or uncomplicated infections in otherwise healthy patients, it is reasonable to proceed with the planned surgery and avoid the inconvenience of a last-minute cancellation. The dilemma lies with patients between these two extremes, for whom decisions regarding the suitability to proceed should be made on an individualized basis
Abbott and colleagues identified four standard outcome measures that are appropriate for widespread use in clinical trials of postoperative pulmonary complications, namely, …
pneumonia, atelectasis, acute respiratory distress syndrome, and aspiration
Potential Patient-related Risk Factors for Postoperative Pulmonary Complications
Advanced age
ASA-PS Class 2 or more
Congestive heart failure
Functionally dependent
Chronic obstructive pulmonary disease
Weight loss
Impaired sensorium
Cigarette use
Alcohol use
Abnormal findings on chest examination
Preexisting pulmonary disease (e.g., recent infection, low oxygen saturation)
Pulmonary hypertension
Anemia
Heart failure
Preexisting sepsis
Poor nutritional status (e.g., albumin concentration)
Obesity (BMI > 30 kg/m2)
Potential Procedure-related Risk Factors for Postoperative Pulmonary Complications
Aortic aneurysm repair
Thoracic surgery
Abdominal surgery
Upper abdominal surgery
Neurosurgery
Head-and-neck surgery
Emergency surgery
Vascular surgery
General anesthesia
Perioperative transfusion
Long-duration procedures
Residual neuromuscular blockade
Potential Laboratory test related Risk Factors for Postoperative Pulmonary Complications
Albumin concentration < 3,5 g/dL
Chest radiograph abnormalities
BUN concentration > 7.5 mmol/L (> 21 mg/dL)
Arterial blood gases are useful in predicting pulmonary function
after lung resection operations and can be used to estimate perioperative pulmonary risk
T or F
F
Arterial blood gases are useful in predicting pulmonary function
after lung resection operations, but do not estimate perioperative pulmonary risk
Describe the Scoring Scheme for the ARISCAT* Perioperative Pulmonary Risk Index
Components of ARISCAT Score Points Assigned
Age
□ ≤50 years: 0
□ 51–80 years: 3
□ >80 years: 16
Preoperative oxygen saturation
□ ≥96%: 0
□ 91%–95%: 8
□ ≤91%: 24
Respiratory infection in prior month: 17
Preoperative anemia (<10 g/dL): 11
Surgical incision location
□ Peripheral: 0
□ Upper abdominal: 15
□ Intrathoracic: 24
Duration of surgery
□ ≤2 h: 0
□ >2–3 h: 16
□ >3 h: 23
Emergency procedure: 8
ARISCAT Score
Low-risk: < 26 points -> 1.6%
Intermediate risk: 26–44 points ->13.3%
High-risk: ≥ 45 points -> 42.1%
Estimates risk of composite endpoint of respiratory infection, respiratory failure, pleural effusion, atelectasis, pneumothorax, bronchospasm, or aspiration pneumonitis
Management of oral antidiabetics medication for surgery
Normal treatment regimen for most noninsulin diabetic medications (metformin, sulfonylureas, repaglinide, GLP-1 agonists, DPP-4 inhibitors) should be continued until (and inclusive of) the day before surgerybut held on the morning of surgery.
The possible exception pertains to SGLT2 inhibitors, which have been associated with euglycemic diabetic ketoacidosis in the postoperative setting. Thus, some guidelines recommend that the medications be discontinued at least 24 hours before elective surgery (up to date diz 3-4 dias antes da cirurgia)
Perioperative corticosteroid supplementation is
needed only when a patient is likely to have suppression of
the hypothalamic-pituitary-adrenal axis. Thus, supplementation is not required for individuals who have received less
than … mg prednisone (or its equivalent) daily, or less
than … weeks of corticosteroids (regardless of dose)
5
3
