Electroacupuncture pretreatment induces rapid tolerance to bupivacaine cardiotoxicity in rats.
BACKGROUND
Evidence suggests that electroacupuncture (EA) protects against arrhythmia and myocardial injury induced by myocardial ischaemia-reperfusion. However, to our knowledge, it remains unknown whether EA could alleviate bupivacaine-induced cardiotoxicity. Therefore, we aimed to explore the effect of EA pretreatment on bupivacaine-induced cardiac arrest and outcomes of cardiopulmonary resuscitation (CPR) in rats.


METHODS
24 adult male Sprague-Dawley rats were randomly divided into two groups: EA (n=12), and minimal acupuncture (MA) (n=12). Rats in both groups were needled at bilateral PC6, ST36, and ST40. Needles in the EA group were electrically stimulated for 60 min. ECG and invasive arterial blood pressure measurements were recorded. Two hours after EA or MA, 10 mg/kg bupivacaine was infused intravenously at a rate of 5 mg/kg/min in all rats. Rats suffering cardiac arrest were immediately subjected to CPR. At the end of the experiment, arterial blood samples were taken from surviving rats for blood gas analysis.


RESULTS
The time from bupivacaine infusion until 20% prolongation of the QRS and QT interval, and the time to cardiac arrest, were notably increased among the rats pretreated with EA. Moreover, EA pretreatment significantly improved mean arterial pressure and heart rate at all monitored points after bupivacaine infusion. The proportion of animals surviving was higher in the EA group (9/12) than the MA group (3/12) at the end of experiment (p=0.039).


CONCLUSIONS
Tolerance to bupivacaine-induced cardiotoxicity appeared to be increased following EA pre-treatment. The mechanism of action underlying the effects of EA on bupivacaine-induced cardiotoxicity requires further investigation.
Department of Anaesthesiology, The First Hospital of Lanzhou University, Lanzhou, PR China.
Jun-Long
JL
Gao
Department of Anaesthesiology, The First Hospital of Lanzhou University, Lanzhou, PR China.
Yu-Lan
YL
Li
Department of Anaesthesiology, The First Hospital of Lanzhou University, Lanzhou, PR China.
Xiu-Mei
XM
Wang
School of Public Health, Lanzhou University, Lanzhou, PR China.
Qian-Long
QL
Zhao
Department of Anaesthesiology, The First Hospital of Lanzhou University, Lanzhou, PR China.
Hai-Jun
HJ
Zhang
Department of Anaesthesiology, The First Hospital of Lanzhou University, Lanzhou, PR China.
Fang-Fang
FF
Han
Department of Anaesthesiology, The First Hospital of Lanzhou University, Lanzhou, PR China.
Xia-Xia
XX
Li
Department of Anaesthesiology, The First Hospital of Lanzhou University, Lanzhou, PR China.
Dong-Hang
DH
Zhang
D000779:Anesthetics, Local / Q000009:adverse effects*; D000818:Animals; D001145:Arrhythmias, Cardiac / Q000139:chemically induced / Q000517:prevention & control*; D062186:Arterial Pressure / Q000502:physiology; D001794:Blood Pressure / Q000502:physiology; D002045:Bupivacaine / Q000009:adverse effects*; D066126:Cardiotoxicity / Q000517:prevention & control; D004195:Disease Models, Animal; D004361:Drug Tolerance / Q000502:physiology; D015671:Electroacupuncture / Q000379:methods*; D006323:Heart Arrest / Q000139:chemically induced / Q000517:prevention & control*; D006339:Heart Rate / Q000502:physiology; D008297:Male; D065129:Pre-Exposure Prophylaxis; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors; D016896:Treatment Outcome
D000779:Anesthetics, Local; D002045:Bupivacaine
ANAESTHETICS; CARDIOLOGY; TOXICOLOGY