Peri-operative+beta+blocker+guidelines

Submitted by Courtney Beach, October 2008

These guidelines were derived from the [|ACC/AHA 2007 Guidelines on Perioperative Cardiovascular Evaluation and Care for Noncardiac Surgery] (90 pages long!).

In light of the recent and on-going POISE trial, which showed increased overall mortality and increased stroke risk in the patients who were given perioperative beta blocker starting the day of surgery, it is generally accepted to modify our prescribing practice. The study confirmed a decreased risk of MI and cardiac events in the beta blockade group. As the study proves significant risk, the following modifications to perioperative beta blockade should be followed:
 * 1) Prescribe only to patients with coronary artery disease (not to patients with minor risk factors unless otherwise indicated. If unsure about CAD presence some would recommend noninvasive testing) undergoing moderate to high risk procedures.
 * 2) Start with a low dose and start early (ie. upon referral for surgery). Titrate slowly to desired effect.
 * 3) Always continue patients on their beta blocker during the perioperative time period who were already on a beta blocker. There is strong evidence that there is increased morbidity and mortality if discontinued. Any contraindications to continuing therapy should be documented


 * Candidates for a Perioperative Beta Blocker**
 * Patients with no or few minimal risk factors who are undergoing low-risk procedures (i.e. outpatient or ophthalmic surgery) are equally as likely to experience adverse effects from beta blockers as benefits.
 * Evidence and the AHA/ACC support using perioperative beta blockade in patients with **moderate** coronary artery disease risk who are undergoing **moderate/high risk** surgeries.
 * Moderate CAD risk can be defined as two minor risk factors or one major risk factors (see below)
 * Moderate risk surgeries in our system include :
 * Open abdominal cases
 * Joint replacements
 * Most neurosurgical procedures.
 * Low risk surgeries in our system include
 * Breast surgery
 * Hernias without entrance into the peritoneum
 * Laparoscopic cholecystectomies
 * Dental
 * Cystoscopies


 * Inclusion Criteria - Major Criteria (1 or more)** //(minor criteria have been removed)//
 * 1) Major vascular procedure
 * 2) Ischemic heart disease (MI, angina, nitrate use, positive stress test, Q’s on EKG, history of CABG or PTCA)
 * 3) Cerebrovascular disease (History of TIA or non-hemorrhagic stroke)
 * 4) Diabetes Mellitus requiring insulin
 * 5) CRF with creatinine > 2.0
 * Note: After the POISE trial, many are considering only those patients with CAD, or another existing indication for beta blocker therapy, or already on beta blockers candidates for perioperative beta blockade.


 * Contraindications to therapy**
 * Heart rate < 55 without pacemaker
 * Active CHF or EF < 30% (unless continuing ongoing therapy)
 * Sick sinus syndrome, 2nd or 3rd degree heart block without pacemaker
 * Known intolerance to beta-blockers
 * S3, rales, or wheezing on exam
 * Asthma/COPD exacerbation, or chronic severe disease
 * Systolic blood pressure //__< 110 mmHg__//, or other evidence of shock
 * Caution in patients on another negative chronotrope [i.e., Ca ++ channel blocker (diltiazem) or alpha-2 agonist (clonidine) or digoxin]

(The POISE trial has shown increased mortality and stroke risk in patients started on Metoprolol ER 100 mg 2-4 hours before surgery. While previous studies have not concluded a definitive time to start beta-blocker therapy, the POISE trial may demonstrate that rapid dosing of beta blockers is part of the risk. Studies have ranged from initiating therapy one month prior to surgery to in preanesthesia the day of surgery). Taking the dose immediately preoperatively**
 * Timing of therapy**
 * In general, it is best to start a beta blocker for perioperative purposes at least several weeks from the surgery date.
 * Start at a low dose and titrate up slowly for the goal heart rate and your goal SBP
 * If a patient qualifies, begin therapy either upon referral for surgery or at the preoperative history and physical appointment.
 * Continue perioperative beta blockers for a minimum of two weeks postoperatively.
 * The aim is to control the patient’s heart rate at 60-75 bpm at the time of surgery.
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 * The patient initiating beta-blocker therapy or on chronic therapy should not miss their dose the day of surgery.
 * If taking a once daily form, the patient may take the medication the night before.
 * If taking a twice a day form, the patient may take it as usual the AM of the day of surgery with a sip of water. This will not interfere with their NPO status for anesthesia.


 * Choice of agent**
 * Patients who qualify for perioperative beta blockade should receive a beta-1 selective agent (i.e., metoprolol or atenolol).
 * Patients already on any beta blocker should continue with their regular medication even if it is nonselective (i.e., propanolol).
 * Note: Atenolol studies in hypertension may suggest improved benefit when dose is split BID. This strategy can be considered perioperatively as well, but many are avoid atenolol altogether and are choosing metoprolol for this reason in addition to the fact that metoprolol does not need to be renally adjusted.
 * The changes for atenolol dosing change for patients with renal insufficiency are as follows:
 * For normal renal function: 50-100 mg Q 24 hr
 * CLcr > 50 mL/min: 100% of the dose (see above) Q 24 hr
 * CLcr 10-50 mL/min: 50% of the above dose Q 48 hr
 * CLcr < 10 mL/min: 30-50% of the above dose Q 96 hr

A post-operative day #1 EKG has been added for perioperative MI surveillance for patients on the perioperative beta-blocker protocol, as they are of moderate to high risk
 * Perioperative Myocardial Infarction****
 * A perioperative MI may result because of increased cardiac demand due to increased sympathetic tone induced by anemia, pain, and hypothermia.
 * Increased coagulability and coronary artery vasoconstriction may also play a role.
 * Up to 50% of PMIs may go unrecognized because:
 * Analgesics blunt pain perception
 * Decreased ability of the patient to communicate post op (sedation, intubation)
 * Signs (hypotension, tachycardia) and symptoms (SOB, nausea) have other explanations during the postoperative period