title: Hypertonic NaCl solution prevents bupivacaine-induced cardiovascular toxicity.
abstract: The effects of various hypertonic solutions on the intraventricular conduction disturbances and on the cardiac arrhythmias caused by the intravenous (i.v.) injection of bupivacaine were studied in sodium pentobarbital anesthetized mongrel dogs. Bupivacaine was injected in 2 doses: 3.0 mg/kg and 6.5 mg/kg. Hypertonic solutions, given intravenously 5 minutes before bupivacaine, were 7.5% NaCl, 5.4% LiCl or 50% glucose (2,400 mOsm/l, 5 ml/kg), or 20% mannitol (1,200 mOsm/l, 10 ml/kg). The highest dose of bupivacaine induced severe cardiac arrhythmias and intraventricular conduction disturbances, as reflected by significant increases in QRS complex duration, HV interval and IV interval, as well as a severe hemodynamic impairment. Significant prevention against intraventricular conduction disturbances and ventricular arrhythmias was observed with 7.5% NaCl (QRS complex duration percent increase: 164 +/- 21% in the non pretreated group vs. 75 +/- 14% in the pretreated group, P less than .01; HV interval percent increase: 131 +/- 16% in the non pretreated group vs. 58 +/- 7% in the pretreated group, P less than .01; cardiac index percent decrease: 46 +/- 6% in the non pretreated group vs. 28 +/- 5% in the pretreated group, P less than .025). The three other hypertonic solutions were ineffective. These findings suggest an involvement of sodium ions in the mechanism of hypertonic protection.
authors.affiliation: Research Division, Heart Institute, University of São Paulo School of Medicine, Brazil.
authors.forename: A
authors.initials: A
authors.lastname: Scalabrini
authors.forename: M dos P
authors.initials: Mdos P
authors.lastname: Simonetti
authors.forename: I T
authors.initials: IT
authors.lastname: Velasco
authors.forename: M
authors.initials: M
authors.lastname: Rocha e Silva
mesh_terms: D000818:Animals; D001145:Arrhythmias, Cardiac / Q000139:chemically induced* / Q000517:prevention & control; D002045:Bupivacaine / Q000633:toxicity*; D004285:Dogs; D005260:Female; D006329:Heart Conduction System / Q000187:drug effects*; D006352:Heart Ventricles / Q000187:drug effects / Q000294:innervation; D007275:Injections, Intravenous; D008297:Male; D012462:Saline Solution, Hypertonic / Q000494:pharmacology*
chemical_list: D012462:Saline Solution, Hypertonic; D002045:Bupivacaine