This Month In Anesthesiology
Predicting Success on the Certification Examinations of the American Board of Anesthesiology (Original Investigation in Education) 212
In-training examination scores and three other factors were predictive. See the accompanying Editorial View on page 6
Blood Pressure, but Not Cerebrospinal Fluid Fentanyl Concentration, Predicts Duration of Labor Analgesia from Spinal Fentanyl 174
Spinal fentanyl concentration did not predict speed of onset or duration of labor analgesia.
Improving Postoperative Pain Management: What Are the Unresolved Issues? (Clinical Concepts and Commentary) 220
How should surgical patients be managed based on the available evidence?
Effects of Prone and Reverse Trendelenburg Positioning on Ocular Parameters 57
Prolonged prone positioning increases intraocular pressure.
Incidence, Reversal, and Prevention of Opioid-induced Respiratory Depression (Review Article) 226
Naloxone and alternative nonopioid antagonists are discussed.
Acute Surgical Anemia Influences the Cardioprotective Effects of β-Blockade: A Single-center Propensity-matched Cohort Study 25
Although perioperative β-blockade decreases cardiac events, it also increases perioperative stroke and mortality. In this retrospective study, the records of all noncardiac, nontransplant surgical patients over 1 yr were retrieved to investigate if β-blockade limits the cardiac reserve to compensate for acute surgical anemia. Of 4,387 patients, 26% received β-blockers within the first 24 hr of surgery. Major acute cardiac events (MACE) were defined as myocardial infarction, nonfatal cardiac arrest, and in-hospital mortality. MACE occurred approximately two times more frequently in β-blocked patients compared with β-blocker naive patients. This difference was restricted to those patients with hemoglobin decreases exceeding 35% of the baseline value. β-blocked patients do not appear to tolerate acute surgical anemia. See the accompanying Editorial View on page 12
Perioperative Intravenous Amiodarone Does Not Reduce the Burden of Atrial Fibrillation in Patients Undergoing Cardiac Valvular Surgery 128
Administration of oral amiodarone reduces atrial fibrillation (AF) after cardiac surgery; however, the hemodynamic safety and efficacy have not been studied in the absence of a preoperative loading dose. In this single-center, double-blind, double-dummy, randomized controlled trial, patients undergoing valvular surgery received either an intravenous loading dose of 300 mg of amiodarone or placebo in the operating room, followed by an infusion of 15 mg/kg per 24 hr for 2 days. Overall AF occurred more frequently in the perioperative intravenous amiodarone group compared with placebo and was associated with older age, recent myocardial infarction, preoperative angina, and use of a calcium channel blocker preoperatively. In patients undergoing cardiac valvular surgery, intravenous amiodarone increased the risk of AF during cardiac valvular surgery.
Randomized Study Assessing the Accuracy of Cervical Facet Joint Nerve (Medial Branch) Blocks Using Different Injectate Volumes 144
A common cause of chronic pain and disability is neck pain and facet joint arthropathy accounts for the majority of cases. Diagnostic blocks of the nerves that innervate the cervical facet joint pain may result in false-positive results. The objective of this randomized, double-blind study was to evaluate the accuracy of medial branch blocks and effect of varying injectate volumes. All patients (n = 24) received cervical medial branch blocks (0.5 or 0.25 ml of bupivacaine and contrast). Aberrant spread was observed more frequently in patients in the 0.5-ml group and was most commonly observed (57%) when an injection at C3 engulfed the third occipital nerve. Among the 86 nerve blocks, foraminal spread occurred in 5 instances using 0.5 ml and in 2 cases with 0.25 ml. No significant difference in any outcome measure was observed between the prone and lateral positions. Reducing the volume during cervical medial branch blocks may improve precision and accuracy.
© 2010 American Society of Anesthesiologists, Inc.