This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a colleague Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (2) Citing Articles via Google Scholar Google Scholar Articles by Tanaka, M. Articles by Nishikawa, T. Search for Related Content PubMed PubMed Citation Articles by Tanaka, M. Articles by Nishikawa, T. Related Collections Cardiovascular Monitoring (Cardiac) Regional Anesthesia

---

REGIONAL ANESTHESIA

Does the Choice of Electrocardiography Lead Affect the Efficacy of the T-Wave Criterion for Detecting Intravascular Injection of an Epinephrine Test Dose?

Department of Anesthesia, Akita University School of Medicine, Akita-city, Japan

Address correspondence and reprint requests to Makoto Tanaka, MD, Department of Anesthesia, Akita University School of Medicine, Hondo 1-1-1, Akita-city, Akita 010-8543, Japan. Address e-mail to mtanaka{at}med akita-u.ac.jp.

Accidental intravascular injection of an epinephrine-containing test dose decreases the T-wave amplitude of a Lead II electrocardiogram (EKG) with 100% sensitivity and specificity on the basis of the T-wave criterion (positive if there is a 25% decrease in amplitude). We designed this study to test whether the choice of EKG lead would affect the efficacy of the simulated intravascular test dose in anesthetized patients. After an 8-h fast and no premedication, 35 healthy patients were anesthetized with end-tidal 2% sevoflurane and nitrous oxide after endotracheal intubation. When hemodynamic stability was obtained, all subjects received 3 mL of normal saline IV, followed 4 min later by 1.5% lidocaine 3 mL plus 15 µg of epinephrine (1:200,000) IV. Heart rate, systolic blood pressure, Leads II (n = 35) and V₅ (n = 35), and either Lead I (n = 17) or III (n = 18), whichever had the greater T-wave amplitude, were continuously recorded for 4 min after the saline and test-dose injections. An IV test dose produced significant increases in heart rate and systolic blood pressure and produced decreases in the T-wave amplitude of all EKG leads studied in all subjects, whereas IV saline elicited no changes in these variables. The maximum percentage decreases in T-wave amplitude of Leads II, I, III, and V₅ were -87% ± 13%, -88% ± 8%, -94% ± 15%, and -86% ± 16%, respectively (mean ± SD; P > 0.05). There was no significant difference in temporal changes in T-wave amplitude among the 4 leads, and sensitivity and specificity were 100% on the basis of the T-wave criterion, irrespective of the lead examined. Our results indicate that Leads II, I, III, and V₅ of the EKG are equally effective for detecting intravascular injection of the epinephrine-containing test dose in sevoflurane-anesthetized adults.

IMPLICATIONS: To determine whether an epidural catheter is in a blood vessel, an epidural test dose containing 15 µg of epinephrine is used. We found that decreases in the T-wave amplitude of Leads I, II, III, and V₅ of the electrocardiogram were equally sensitive and specific for detecting intravascular injection of the test dose in sevoflurane-anesthetized adult patients.

This article has been cited by other articles:

				P. Taggart, V. N. Batchvarov, P. Sutton, G. Young, S. Young, and D. Patterson Repolarization Changes Induced by Mental Stress in Normal Subjects and Patients with Coronary Artery Disease: Effect of Nitroglycerine Psychosom Med, January 1, 2009; 71(1): 23 - 29. [Abstract] [Full Text] [PDF]

				J. Guay The epidural test dose: a review. Anesth. Analg., March 1, 2006; 102(3): 921 - 929. [Abstract] [Full Text] [PDF]