B P3 C23 Anesthesia and Noncardiac Surgery Flashcards
If the patient is clinically stable, identification of known _________ can foster the implementation of guideline-based risk reduction therapies
Asymptomatic or symptomatic stable CAD or risk factors for CAD
In determining the extent of preoperative evaluation, it is important __________ testing unless the results will affect perioperative management.
Not to perform testing
Currently no significant adjunctive therapy that ameliorates cardiovascular surgical risk.
In addition, the use of medications or interventions should mirror those that would be implemented in the absence of surgery.
The primary reason to perform risk assessment is to determine _________ and _________
Determine clinical cardiovascular instability and suitability for surgery.
Multiple older studies have demonstrated an increased incidence of reinfarction after noncardiac surgery if the previous MI had occurred ___________ of the operation
Within 6 months
The AHA/ACC Task Force on Perioperative Evaluation of the Cardiac Patient Undergoing Noncardiac Surgery has suggested that the highest-risk patients are those within _________days of MI, during which time plaque and myocardial healing occur.
Within 30 days of MI
A hypertensive crisis in the postoperative period—defined as diastolic BP __________ and clinical evidence of ___________—poses a definite risk for MI and cerebrovascular accident (CVA, stroke).
Higher than 120 mm Hg
Impending or actual end-organ damage
Similarly, intraoperative hypotension is associated with both type 2 MI and increases in postoperative mortality.
Iatrogenic precipitants of hypertensive crises include
Abrupt withdrawal of clonidine or beta blocker therapy before surgery
Chronic use of monoamine oxidase inhibitors with or without sympathomimetic drugs
Inadvertent discontinuation of antihypertensive therapy
In the Intraoperative Norepinephrine to Control Arterial Pressure (INPRESS) study, a multicenter, randomized, clinical trial of an individualized management strategy aimed at achieving a _______________ or standard management strategy of treating systolic BP less than 80 mm Hg or lower than 40% from the reference value during and for 4 hours following surgery.
Among 292 patients who completed the trial, management targeting an individualized systolic BP, compared with standard management, reduced the risk of postoperative organ dysfunction.6
Systolic BP within 10% of the reference value (i.e., patient’s resting systolic BP)
The preoperative evaluation should aim to identify the underlying coronary, myocardial, and valvular heart disease and assess the severity of _______ and ________
Systolic and diastolic dysfunction
_______ HF is associated with a significant increase in postoperative morbidity and mortality when controlling for other comorbidities
Worsening preoperative HF
In the absence of a surgical e gency, patients with decompensated HF should be treated to achieve a euvolemic, stable state before operation. Ischemic cardiomyopathy is of greatest concern because the patient has the additional substantial risk for the development of further ischemia, which can lead to myocardial necrosis and potentially induce a downward spiral.
_______ is associated with the highest risk for cardiac decompensation in patients undergoing elective noncardiac surgery
Critical aortic stenosis
Thus, the presence of any of the classic triad of angina, syncope, and HF in a patient with aortic stenosis should prompt further evaluation and potential interventions (usually valve replacement)
________ is a bridging option for selected patients who cannot undergo valve replacement or percutaneous intervention in the short term.
Aortic valvuloplasty
_______ is associated with a lower risk for perioperative complications than aortic stenosis,
Mitral valve disease
In perioperative patients with a functioning prosthetic heart valve, __________ and _________ require management
Antibiotic prophylaxis and anticoagulation
Common practice in patients undergoing noncardiac surgery with a mechanical prosthetic valve in place is cessation of warfarin ________
3 days before surgery
Oral anticoagulants can then be resumed on postoperative ________
Day 1
According to the 2020 AHA/ACC guidelines on management of valvular heart disease, 9heparin can usually be reserved for high-risk patients.
High risk is defined by
Presence of a mechanical mitral or tricuspid valve
Mechanical aortic valve in the presence of certain risk factors, including AF, previous thromboembolism, hypercoagulable condition
Older-generation mechanical valves
Ejection fraction lower than 30%
More than one mechanical valve
Bridging anticoagulation therapy with heparin during the preoperative time interval when the INR is subtherapeutic should be made on an individualized basis, with the risks of bleeding weighed against the benefits of thromboembolism prevention.
The 2020 ACC/AHA guidelines also note that it is reasonable to consider the need for bridging anticoagulant therapy around the time of invasive procedures in patients with bioprosthetic heart valves or annuloplasty rings who are receiving anticoagulation for AF on the basis of the CHA2DS2-VASc score weighed against the risk of bleeding.
________ and _______ present a major concern in patients with congenital heart disease.
Pulmonary hypertension and Eisenmenger syndrome
________ has traditionally been avoided in these patients because of the potential for sympathetic blockade and worsening of the right-to-left shunt
Regional anesthesia
Cardiac arrhythmias frequently occur in the perioperative period, particularly in older adults or patients undergoing thoracic surgery.
Predisposing factors include
Previous arrhythmias
Underlying heart disease
Hypertension
Perioperative pain (e.g., hip fractures)
Severe anxiety, and other situations that heighten adrenergic tone
Examples of High (reported cardiac risk often >5%) Risk Surgical Procedures
Aortic and other major vascular surgery
Peripheral vascular surgery
Examples of intermediate (reported cardiac risk often 1-5%) Risk Surgical Procedures
Intraperitoneal and intrathoracic surgery
Carotid endarterectomy
Head and neck surgery
Orthopedic surgery
Prostate surgery
Examples of low (reported cardiac risk often <1%) Risk Surgical Procedures
Endoscopic procedures
Superficial procedure
Cataract surgery
Breast surgery
Ambulatory surgery
Active cardiac risk conditions for which patients should undergo evaluation and treatment before noncardiac surgery
Unstable coronary syndrome
Decompensated HF (NYHA IV, worsening or new-onset HF)
Significant arrhythmias
Severe valvular disease
__________ is one of the strongest determinants of perioperative risk and the need for invasive monitoring.
Exercise tolerance
Activities equivalent to 4 METs
Do light work around the house such as dusting or washing dishes?
Climb a flight of stairs or walk up a hill?
Walk on level ground at 4 mph (6.4 kph)?
Run a short distance?
Do heavy work around the house such as scrubbing floors or lifting or moving heavy furniture?
Participate in moderate recreational activities such as golf, bowling, dancing, doubles tennis, or throwing a baseball or football?
Factors that would warrant pharmacologic stress testing in the perioperative risk assessment that would impact decision making
Poor OR unknown functional capacity (<4 METs)
Components of Revised cardiac Risk Index
High-risk type of surgery
History of ischemic heart disease
History of congestive HF
History of cerebrovascular disease
Preoperative treatment with insulin
Preoperative serum creatinine concentration greater than 2.0 mg/ dL.
________ standard tool for assessing the probability of perioperative cardiac risk in a given individual and serves to direct the decision to perform cardiovascular testing and implement perioperative management protocols.
RCRI
Components of Gupta perioperative myocardial infarction and cardiac arrest
Type of surgery
Dependent functional status
Abnormal creatinine level
American Society of Anesthesiologists class
Increasing age
In patients with known IHD or myocardial ischemia, initiation of a titrated low-dose __________ regimen may be considered before surgery.
Beta blocker
The ________ has traditionally served as an initial evaluation for the presence of CAD
Exercise electrocardiogram (ECG)
Patients with poor exercise capacity, in contrast, may not achieve an adequate HR and BP for diagnostic purposes on electrocardiographic stress tests
_______ testing has became popular for many high-risk patients either cannot exercise or have limitations to exercise (e.g., patients with intermittent claudication or knee arthritis
Pharmacologic stress testing
Several studies have shown that the presence of a redistribution defect on dipyridamole or adenosine thallium or sestamibi imaging in patients undergoing peripheral vascular surgery predicts an increased risk for postoperative cardiac events
Pharmacologic stress imaging is best used in patients at ___________
Moderate clinical risk
Findings in stress perfusion imaging associated with higher risk
Larger areas of defect
Increased lung uptake
Dilation of the left ventricular cavity
One advantage of this test is that it d cally assesses myocardial ischemia in response to increased inotropy and HR, stimuli relevant to the perioperative period.
Stress echocardiography
The presence of __________ is the best predictor of increased perioperative risk, with large areas of contractile dysfunction having secondary importance.
New wall motion abnormalities occurring at a low HR
In a large substudy of the _______ trial of more than 10,400 patients, higher preoperative levels of NT-proBNP associated directly with higher levels of cardiovascular events.
Vascular Events in Noncardiac Surgery Cohort Evaluation (VISION) trial
____________ were traditionally c ered the time of greatest stress and risk for myocardial ischemia, but ______ may actually engender even greater risk.
Laryngoscopy and intubation
Extubation
All inhalational agents have ________ and lead to decreases in myocardial oxygen demand.
Reversible myocardial depressant effects
_______ offer the advantages of hemodynamic stability and lack of myocardial depression.
High-dose narcotic techniques
__________ were frequently considered the “cardiac anesthesia” and were advocated for use in all high-risk patients, including those undergoing noncardiac surgery.
Narcotic-based anesthetics
The disadvantage of these traditional high narcotic techniques is the requirement for postoperative ventilation.
Used for both induction and maintenance of general anesthesia; can cause profound hypotension because of reduced arterial tone with no change in HR.
Propofol
Spinal or epidural techniques can produce _________, which can reduce BP and slow the HR.
_______ can also evoke reflex sympathetic activation mediated above the level of blockade, which might lead to myocardial ischemia.
Sympathetic blockade
Spinal anesthesia and lumbar or low thoracic epidural anesthesia
The primary clinical difference between epidural and spinal anesthesia is the ability to ________, as opposed to a single dose with spinal anesthesia,
Provide continuous anesthesia or analgesia with placement of an epidural catheter
The major issue with MAC is the ________ because the tachycardia associated with inadequate analgesia may be worse than the potential hemodynamic effects of general or regional anesthesia.
Ability to block the stress response adequately
________ is the strongest predictor of perioperative ischemia.
Tachycardia
In the DECREASE studies, HR control reduced the incidence of perioperative MI, with the greatest benefit achieved if HR was controlled to _______________
Less than 70 beats/min
The ___________ trial demonstrated that an acute high-dose beta blockade protocol in patients naïve to beta adrenergic blockade therapy was associated with hypotension and a higher rate of stroke in the metoprolol arm
POISE
Dawood and associates, as cited in the guidelines, demonstrated that fatal perioperative MI occurs predominantly in patients with ___________, but the severity of preexisting stenosis did not predict the infarct territory.
Multivessel coronary disease, especially left main and three-vessel disease
Fatal events occurred primarily in patients with advanced fixed stenoses, but that the infarct may result from plaque rupture in a _____________ of the diseased vessel.
Mild or only moderately stenotic segment
Epidural anesthesia may decrease ______________ compared with general anesthesia
Platelet aggregability
Both vascular and nonvascular death increased similarly with increasing troponin T levels, and more than half of all deaths were from ________ causes
Nonvascular
Indeed, a troponin T level of 0.02 ng/mL was associated with more than a twofold risk for death. With a troponin T level of 0.3 ng/mL or higher, the hazard ratio (HR) for death increased to more than 10-fold above that in patients without any elevation in troponin
Perioperative MImhas peak incidence on the ______ days
Second and third postoperative days
Traditionally, perioperative MI has been associated with 30% to 50% short-term mortality, but recent series have reported a fatality rate of less than 20% for perioperative MI.
The finding that tachycardia, hypotension, and hypertension in the operative suite predicted release of troponin suggests a hemodynamic consequence rather than plaque rupture event (________ vs. type 1 MI).
Type 2
Minimum duration of DAPT before undergoing noncardiac surgery
BMS
DES
BMS: >/= 30 days (Class 1 to proceed with surgery)
DES: >/= 6 months (Class 1); 3-6 months (Proceeding with surgery may be considered; delayed surgery risk is greater than stent thrombosis risk)
ACC/AHA guidelines suggest that perioperative beta blockers can be considered on a case-by-case basis in patients with
Significant myocardial ischemia
Three or more RCRI risk factors
Compelling long-term indication for beta blockers
If beta blockers are to be used, it is recommended that initiation begin _______ before surgery.
1 day or more
Initiation on the day of surgery has been associated with an increase in stroke and mortality. In hospital, short-acting oral or IV beta blockers should be used to permit titration to hemodynamics.
No specific BP or HR targets have been validated, although BP control to ________ and HRs of _________ may be reasonable when beta blockers are used.
Less than 140/90 mm Hg
60 to 80 beats/min
Starting _______ therapy should be considered in patients who meet ACC/AHA lipid guideline recommendations and in cardiovascular high-risk patients, because they merit this treatment even without surgery.
Statin
Statin use was associated with a 45% reduction in adverse events, including a 5% absolute reduction in 30-day mortality.
Statin use was a ciated with reductions in noncardiac events, including a 47% reduction in respiratory complications, 59% reduction in VTE, and 35% reduction in infectious complications. 35 The evidence suggests that statin therapy should be continued during the perioperative period.
In the _________, Carson and colleagues randomly assigned hip fracture patients to a liberal transfusion strategy (hemoglobin threshold of 10 g/dL) or a restrictive transfusion strategy (symptoms of anemia or at physician’s discretion for hemoglobin level <8 g/dL).
A liberal transfusion strategy, compared with a restrictive strategy, did not reduce rates of death or inability to walk independently on 60-day follow-up and did not reduce in-hospital morbidity in elderly patients at high cardiovascular risk.
FOCUS (Transfusion Trigger Trial for Functional Outcomes in Cardiovascular Patients Undergoing Surgical Hip Fracture Repair) trial
High risk surgical risk >5%
Pre-operative assessment before non-cardiac surgery
Antiplatelets in NCS
Anticoagulation in NCS
Bleeding risk according to type of non-cardiac surger
Recommendations for management of antiplatelet therapy in patients undergoing non-cardiac surgery
P2Y 12inhibitor interruption after percutaneous coronary intervention before elective non-cardiac surgery
Recommendations for management of oral anticoagulation therapy in patients undergoing non-cardiac surgery
Peri-operative management of non-vitamin K antagonist oral anticoagulant according to the periprocedural risk of bleeding.
Timing of last non-vitamin K antagonist oral anticoagulant dose before elective NCS according to renal function.
