Cardio

Anesthesiology 2009; 111:690 – 4

Copyright © 2009, the American Society of Anesthesiologists, Inc. Lippincott Williams & Wilkins, Inc.

Perioperative -Blockade, Discontinuation,
and Complications
Do You Really Know It When You See It?
the New England Journal of Medicine in a double-blind
crossover efficacy trial in which 10 of 20 patients with
angina sustained ischemic complications offtherapy.5
Subsequently, Kaplan et al. reported observational data
(including the first noncardiac surgery cohort) and Slogoff and Keats, a randomized trial, suggesting that continuation to within 12–24 h of surgery was safe, although
neither specifically address postoperative use.6 – 8 In fact,
-blockers were often discontinued permanently shortly
after myocardial revascularization because itwas felt that
patients would no longer need them.9
In 1981, several years after his landmark Cardiac Risk
Index study, Lee Goldman reported case vignettes of
(only) two patients with known ischemic disease on
chronic propranolol therapy undergoing vascular surgery, outlining the potential hazards of perioperative
withdrawal.10,11 Both patients developed tachycardia
and signs of myocardialischemia early postoperatively,
one with overt hemorrhage and evidence of heart failure. Both responded eventually to reinstitution of propranolol. He speculated the cases were “definitive” or
“suggestive” of propranolol withdrawal, recommending
continuation of therapy, accompanied by a “word of
caution” that “other postoperative conditions mimic the
withdrawal rebound syndrome and are probablyfar
more common than the syndrome itself.” In the only
randomized trial of withdrawal in patients undergoing
noncardiac surgery, Ponten et al. in 1982 reported on 48
patients, all with hypertension and/or ischemic heart
disease randomized to either preoperative withdrawal or
continuation.12 They noted “high and unstable heart
rate” during both intubation and extubation in the withdrawngroup, and decreased blood pressure in all patients during induction of anesthesia, most evident in the
continued group. In a subset of patients instrumented
with pulmonary artery catheters, continued patients
manifested lower cardiac index and stroke work with
higher wedge pressure and systemic vascular resistance.
ST-segment changes were more common in withdrawn
patients, whereas myocardialinfarction (MI) was more
common in the continued group (4 of 11 vs. 0 of 9
patients with postoperative enzyme measurements). In
their conclusion, the authors recommended continuation of -blockade, but with the caveat that any benefits
are obtained “at the expense of a hypokinetic circulation” suggesting concomitant vasodilator therapy to offset these effects.
Throughout the 1980s, cardiologistsdebated the existence of a specific -blocker withdrawal syndrome and
whether it occurred with the increasingly popular 1-

This article has been selected for the ANESTHESIOLOGY
CME Program. Learning objectives and disclosure and
ordering information can be found in the CME section at
the front of this issue.

ATTEMPTING to articulate his thoughts on the legal
definition of obscenity in the1960s, Supreme Court
Justice Potter Stewart, opined “I know it when I see it.”*
This approach, celebrated at that time as intuitive and
pragmatic, was one he later recanted. Clinicians take a
similar approach to situations that are often more complex than they appear. In this issue of ANESTHESIOLOGY, van
Klei et al. report an analysis of patterns of perioperative
-blocker prescription inpatients undergoing orthopedic surgery.1 They conclude that their results provide
confirmatory evidence to one of the two class 1 recommendations for “perioperative -blockade” of the American College of Cardiology/American Heart Association
Perioperative Evaluation Guidelines Committee, paraphrased by the authors as “not to withdraw -blocker
therapy.”2† As the current guideline comprise only a...