This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal 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 Google Scholar Google Scholar Articles by Echt, D. S. Articles by Coxe, D. R. Search for Related Content PubMed PubMed Citation Articles by Echt, D. S. Articles by Coxe, D. R.

Circulation, Vol 80, 1003-1009, Copyright © 1989 by American Heart Association

ARTICLES

pH-dependent effects of lidocaine on defibrillation energy requirements in dogs

DS Echt, EL Cato and DR Coxe
Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee 37232.

Lidocaine increases the energy required for ventricular defibrillation in dogs. Because sodium channel-blocking agents that are weak bases have pH-dependent electrophysiologic effects, we investigated the pH dependence of lidocaine (pKa, 7.9) on internal defibrillation energy requirements in 28 dogs with atrial spring and left ventricular patch electrodes. Results of defibrillation testing were used to derive 50% and 90% successful energy requirements (ED50 and ED90) using logistic regression and were compared with analysis of variance. Acidosis produced by hydrochloric acid infusion decreased the arterial pH from 7.40 +/- 0.05 (SD) to 7.18 +/- 0.03 (n = 8, p less than 0.01), but no significant change in ED90 was observed (14 +/- 4 to 16 +/- 6 J). Lidocaine infusion to therapeutic levels (4.2 +/- .07 micrograms/ml) at normal pH (7.42 +/- 0.02) increased ED90 from 13 +/- 3 to 17 +/- 3 J (n = 6, p less than 0.05), and subsequent acidosis (pH 7.19 +/- 0.02, p less than 0.01) exacerbated this effect of lidocaine on ED90 (22 +/- 5 J, p less than 0.05). Alkalosis produced by respirator hyperventilation increased the arterial pH from 7.41 +/- 0.03 to 7.60 +/- 0.03 (n = 8, p less than 0.01), with a fall in ED90 from 13 +/- 4 to 8 +/- 3 J (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

This article has been cited by other articles:

				M. P. Anstadt and J. E. Lowe Cardiopulmonary Resuscitation Card. Surg. Adult, January 1, 2008; 3(2008): 487 - 506. [Full Text]

				M. P. Anstadt and J. E. Lowe Cardiopulmonary Resuscitation Card. Surg. Adult, January 1, 2003; 2(2003): 471 - 494. [Full Text]