USING PRACTICE GUIDELINES TO IMPROVE OUTCOME
From the 59th Postgraduate Assembly in Anesthesiology, presented by the New York State Society of
Anesthesiologists, December 9-13, 2005
| THE AMERICAN COLLEGE OF CARDIOLOGY/AMERICAN HEART ASSOCIATION ALGORITHM —Lee A.
Fleisher, MD, Robert D. Dripps Professor and Chair, Department of Anesthesia, and Professor of Medicine, University
of Pennsylvania School of Medicine, Philadelphia
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| History: in 1994, committee established to consider perioperative guidelines from American Heart Association (AHA)
and American College of Cardiology (ACC); committee chairman careful and thoughtful in ensuring guidelines that
emphasize choice of anesthesia best made by anesthesia provider; excellent preoperative clinic and good evaluation
eliminate need to send patient to cardiologist (no need for cardiology consultation to “clear the patient”); algorithm
more of consensus document and review of literature; approved by board of Society of Cardiovascular Anesthesiologists;
published in Circulation, Journal of American College of Cardiology, and Anesthesia and Analgesia (in
1996); in 2002, updated guidelines published
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| β-blockers: studies question how widely β-blocker trials can be generalized; because of Surgical Care Improvement
Project, guidelines now being written for pay-for-performance; several groups state that β-blockers should be given to
all high-risk patients undergoing major noncardiac surgery
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| Goals of committee: to provide framework for considering cardiac risk in noncardiac surgery and use knowledge in
individual patient; frequently, patients seen who should be treated more effectively by primary care physician (eg, receiving
β-blockers due to past myocardial infarction [MI]; anesthesia provider would then continue β-blocker therapy);
may be necessary to stop surgery for preoperative cardiac evaluation (may not alter outcome) vs treating patient
at home due to chronic implications of disease; from risk-benefit perspective, some treatments may cause more harm
than good (eg, preparing patient’s heart for surgery); statins, β-blockers, and aspirin “are all the right things to do”
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| General approach: preoperative testing recommended only if information would change surgical procedure; may
consider endovascular procedure rather than open cardiac procedure (stents may require replacement every 2 yr), then
consider medical therapy or monitoring, and postponement of surgery for stabilization; ambulatory surgery requires
better evaluation (to ensure patient in better condition); data from Mayo Clinic show lower than expected 30-day mortality
after ambulatory surgery; important to consider role of consultant, review available data, obtain history, and perform
physical examination; communicate severity and stability of cardiovascular status; mentioned nothing about
anesthetic; clinical evaluation of history, physical examination, exercise tolerance, and surgical procedure
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| Major clinical predictors: high correlation with perioperative cardiac morbidity, irrespective of type of procedure;
unstable coronary syndromes (perioperative period known as hypercoagulable state; includes unstable angina and previous
MI with evidence of important ischemic risk [by clinical symptoms or noninvasive test]); decompensated congestive
heart failure (CHF); significant arrhythmias (unclear; necessary to better define which arrhythmias sufficient
to require further evaluation); severe aortic stenosis (not solely valvular disease; valvuloplasty may carry as much risk
as surgery itself); with medical conditions, consider delaying or canceling noncardiac surgery or consider coronary angiography;
unstable angina patient with truly emergent surgery may proceed
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| Intermediate clinical predictors: unclear whether all patients require further evaluation; include mild angina pectoris,
previous MI (by history or pathologic Q waves), compensated or previous CHF, diabetes mellitus, and elevated
creatinine
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| Minor clinical predictors: associated with coronary disease, but not necessarily associated with elevated perioperative
risk; Lee Revised Cardiac Risk Index most widely used for risk assessment; provides idea about probability of extensive
disease and possible need for β-blockers; American Society of Anesthesiologists (ASA) classification “does
almost as well” as Lee Revised Cardiac Risk Index; ask about activity level, watch patient walk up and down stairs, or
ask about carrying “a bag or two of groceries up two flights of stairs”; studies indicate better exercise capacity associated
with lower perioperative complication rate
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 | Intermediate clinical predictors and low-risk surgery: proceed directly to operating room; consider noninvasive testing
(invasive testing may be unnecessary); Falcone study unable to find benefit for algorithm in randomized trial for
high-risk surgery in patient with good exercise capacity
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| Risk factors: ≤2 with low functional capacity, high-risk surgery, and intermediate-risk predictor, can proceed to surgery;
≥2 with recent angiography, indications for angiography, or unstable angina, perform noninvasive testing; if
patient ambulatory and electrocardiography (ECG) does not show important resting abnormalities, consider exercise
stress test; with resting abnormalities or if unable to perform exercise stress test, “do some sort of testing”;
choice of testing decided by cardiologist; may be dipyridamole thallium imaging (tests flow heterogeneity, not
function; does not provide good baseline echocardiography measurement to look at valve function or ejection fraction
[EF]) or echocardiography
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| Echocardiography: evidence shows poor EF on results in worse outcome; most anesthesia providers can assess poor
functional capacity; “[echocardiography] doesn’t add anything”; required only in patient with current or poorly controlled
heart failure of unknown etiology; useful to differentiate heart failure from pulmonary failure; class II indication
for those with previous heart failure and dyspnea of unknown etiology
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| McFalls study: looking at elective major vascular surgery (left main aortic stenosis excluded) in single- or double-vessel
disease and asymptomatic triple-vessel disease, found that those assigned to revascularization had 77% survival
to 2.6 yr; no difference between those assigned to no revascularization; early deficit or increased mortality for those
assigned to coronary artery bypass grafting (CABG) or percutaneous coronary intervention (PCI)
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| β-blockers: patient with baseline positive ischemic heart disease with positive stress test, β-blockers administered ≤7
days in advance (on average 37 days), titrated to heart rate (HR) of 60/min preoperatively and 80/min intraoperatively,
showed significant improvement in outcome; several studies indicate that without HR control, and when administered
to everyone, β-blockers do not appear to make significant difference; no difference in outcome in patient with >5 segments
of new regional wall motion abnormalities on dobutamine stress echocardiography; continue in patient on previous
β-blocker therapy; begin preoperatively in patient with positive stress test undergoing vascular surgery; speaker
administers intraoperatively to control HR, then titrates near end of surgery if HR >80/min (extubation period greatest
risk)
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| DO SEDATION GUIDELINES FOR NONANESTHESIOLOGISTS IMPROVE OUTCOME? —Beverly K. Philip,
MD, Professor of Anesthesia, Harvard Medical School, and Director, Day Surgery Unit, Brigham and Women’s Hospital,
Boston, MA
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| Case: facility to open interventional radiology suite across town; radiologists and nurses will provide sedation
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| Trends in surgery: conventional open surgery declining; minimally invasive surgery increasing; interventional medical
procedures also increasing; more procedures appropriately performed under sedation rather than under general anesthesia
(GA); practitioners not trained as anesthesia providers giving sedation for most diagnostic and therapeutic
procedures; all patients should receive safe sedation care, regardless of person giving sedation
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| Safety concerns: surgeons often offer sedation instead of GA because of belief in increased safety; data from freestanding
surgery centers show complication rate higher even than GA (probably due to adequacy of monitoring and
attention to patient); data from plastic surgery show numerous complications (eg, intravascular reactions requiring
treatment, respiratory arrest, unplanned intubation, cardiac arrest); data from ASA Closed Claims Database looking at
safety of monitored anesthesia care (MAC) show that number of claims smaller than for GA, but growing; comparing
MAC and GA, proportion of claims due to death and proportion due to respiratory events equal; in both groups, inadequate
observation most common event precipitating claim; no difference in proportion of claims for substandard anesthesia
care or amount of payment (≈$100,000); proposition that MAC inherently safer than GA not well
substantiated by available data
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| Definitions of sedation and anesthesia
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| Continuum of Depth of Sedation, Definition of General Anesthesia and Levels of Sedation/Analgesia: defines 4 levels
of increasing depth of sedation and anesthesia using 4 categories of criteria, ie, responsiveness, ability to maintain
airway, spontaneous ventilation, and cardiovascular function
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| Core definitions (level of patient responsiveness): minimal sedation (anxiolysis); moderate sedation/analgesia
(known formerly as conscious sedation; patient responds purposefully to verbal or light tactile stimulation); deep
sedation/analgesia (patient responds purposefully following repeated or painful stimulation); GA (patient not
arousable, even by painful stimulation); reflex withdrawal from painful stimulus not considered purposeful response
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| Other definitions: sedation-to-anesthesia continuum; not always possible to predict how each patient will respond;
practitioners intending to produce certain level of sedation must be able to rescue patient if sedation goes deeper
than originally intended
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| Practice Guidelines for Sedation and Analgesia by Nonanesthesiologists: designed to help develop policies for sedation/analgesia
by nonanesthesiologists; covers spectrum of requirements; includes focused history and physical examination,
preprocedure preparation (eg, patient education, fasting, consent), monitoring, recording of monitored
parameters, personnel dedicated to patient monitoring and safety, education and training of personnel, appropriately
sized emergency equipment, supplemental O2 if hypoxemia anticipated or develops; multiple sedative/analgesic
drugs increase all effects; titrate drugs to achieve desired effect; propofol and methohexital require care for deep sedation;
even if moderate sedation intended, patient receiving propofol (and similar drugs) needs to receive care consistent
with that required for deep sedation; practitioner must be qualified to rescue patient from any level of
sedation, including GA; difficult to keep patient at moderate level of sedation; response limited to reflex withdrawal
from painful stimulus not purposeful response and specifically represents state of GA
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| Statement on Safe Use of Propofol: gives education, training, and skills needed by person responsible for use of propofol;
must be able to deal with medical complications, proficient in airway management, and present during sedation;
second person must be available to monitor patient; requires education and training to identify changes of
GA, to assist in management of complications, and to be present and completely dedicated to monitoring
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| Monitoring: assess level of consciousness without interruption; identify early signs of hypotension, bradycardia, apnea,
and airway obstruction; monitor standard vital signs; monitoring for presence of exhaled CO2 should be utilized
when possible (movement of chest does not dependably identify airway obstruction or apnea)
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| Additional points: similar concerns with any IV induction agent for sedation (eg, thiopental, methohexital, etomidate);
combination of drugs, including adding sedatives and analgesics to propofol, may increase likelihood of
adverse outcomes; rescue defined as intervention by practitioner proficient in airway management and advanced
cardiac life support (ACLS) to correct adverse physiologic consequences of deeper level of sedation and return
patient to original level; inappropriate to continue procedure at unintended level of sedation
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| Effects of guidelines: unclear whether guidelines make any difference for nonanesthesiologists or anesthesiologists;
nurse-administered propofol sedation (NAPS) course involves 2 wk of training (originally taught by anesthesiologist,
now nurse-to-nurse training); required to receive ACLS training, watch video, take test on drug properties, and observe
other nurses performing sedation; technique consists of 30- to 50-mg boluses, plus another 10 to 20 mg if patient
moves; goal to achieve end points of complete analgesia and amnesia; most procedures performed in lateral position;
monitoring recommendations include palpate exhaled air, observe chest and abdomen movement, and observe vital
signs; does not include airway obstruction
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| Outcome data: gastrointestinal (GI) and emergency medicine literature support use of propofol sedation; studies
showed prolonged apnea with hypoxemia, laryngospasm, and colonic perforations; no studies of propofol sedation reported
in anesthesiology literature; mortality ≈1 in 300,000 for lower-risk patients and procedures
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| Conclusion: guidelines must be developed in GI, emergency medicine, and anesthesiology communities; practitioners
in larger institutions with large number of patients most likely following guidelines and “doing a good job”; extrapolation
to clinician “on the corner, alone, giving propofol sedation, that’s the scary part”; areas of focus include reports of
adverse outcomes, provider education and training, patient selection (eg, comorbidity, obesity, airway assessment),
adequate monitoring, and fasting status
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Educational Objectives
| The goal of this program is to educate the listener about the American College of Cardiology/American Heart Association
(ACC/AHA) algorithm and sedation guidelines for nonanesthesiologists. After hearing and assimilating this program,
the participant will be better able to:
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| 1. Summarize the history of the development of the ACC/AHA algorithm.
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| 2. Examine the general approach to preoperative cardiac evaluation.
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| 3. Review the major clinical predictors of increased perioperative cardiovascular risk.
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| 4. Analyze the safety concerns associated with sedation by nonanesthesiologists.
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| 5. Discuss the American Society of Anesthesiologists’ Continuum of Depth of Sedation and Practice Guidelines for
Sedation and Analgesia by Nonanesthesiologists documents.
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Notes
Discussed on This Program
Etomidate [Amidate]
Methohexital sodium [Brevital Sodium]
Propofol [Diprivan]
Thiopental sodium [Pentothal]
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To locate lectures of related interest, or to see a complete listing of Audio-Digest CME Programs, including written summaries.
Suggested Reading
Bhananker SM et al: Injury and liability associated with monitored anesthesia care: a closed claims analysis. Anesthesiology
104:228, 2006; Eagle KA et al: ACC/AHA guideline update for perioperative cardiovascular evaluation
for noncardiac surgery--executive summary: a report of the American College of Cardiology/American Heart Association
Task Force on Practice Guidelines (Committee to Update the 1996 Guidelines on Perioperative Cardiovascular
Evaluation for Noncardiac Surgery). J Am Coll Cardiol 39:542, 2002; Eagle KA et al: Guidelines for perioperative
cardiovascular evaluation for noncardiac surgery. Report of the American College of Cardiology/American Heart Association
Task Force on Practice Guidelines (Committee on Perioperative Cardiovascular Evaluation for Noncardiac Surgery).
J Am Coll Cardiol 27:910, 1996; Falcone RA et al: The value of preoperative pharmacologic stress testing
before vascular surgery using ACC/AHA guidelines: a prospective, randomized trial. J Cardiothorac Vasc Anesth
17:694, 2003; Fleisher LA: Strategies to reduce cardiac risk in noncardiac surgery: where are we in 2005? Anesthesiology
102:881, 2005; Froehlich JB et al: American College of Cardiology/American Heart Association preoperative
assessment guidelines reduce resource utilization before aortic surgery. J Vasc Surg 36:758, 2002; Froehlich JB et
al: Anaesthesia and the cardiac patient: the patient versus the procedure. Heart 87:91, 2002; Green SM et al: Propofol
in emergency medicine: pushing the sedation frontier. Ann Emerg Med 42:792, 2003; McFalls EO et al: Coronary-artery
revascularization before elective major vascular surgery. N Engl J Med 351:2795, 2004; Rex DK et al:
Safety of propofol administered by registered nurses with gastroenterologist supervision in 2000 endoscopic cases. Am J
Gastroenterol 97:1159, 2002; Walker JA et al: Nurse-administered propofol sedation without anesthesia specialists
in 9152 endoscopic cases in an ambulatory surgery center. Am J Gastroenterol 98:1744, 2003; Yagiela JA: Making
patients safe and comfortable for a lifetime of dentistry: frontiers in office-based sedation. J Dent Educ 65:1348, 2001.
Faculty Disclosure
In adherence to ACCME guidelines, the Audio-Digest Foundation requests all lecturers to disclose any significant financial
relationship with the manufacturer or provider of any commercial product or service discussed. For this issue, the
faculty reported nothing to disclose.
Drs. Fleisher and Philip were recorded at the 59th Postgraduate Assembly in Anesthesiology, presented December 9-13,
2005, by the New York State Society of Anesthesiologists (NYSSA), Inc. and held in New York. The Audio-Digest
Foundation thanks the speakers and the NYSSA for their cooperation in the production of this program.
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