Effects of pericardial lidocaine on hemodynamic parameters and responses in dogs anesthetized with midazolam and fentanyl.
OBJECTIVE
Tachycardia during anesthesia should be avoided, especially during off-pump coronary artery bypass graft surgery. Decreasing heart rate without reducing cardiac contractility is an ideal goal. To achieve this, the authors attempted to block the cardiac nerves by pericardial administration of local anesthetic.


METHODS
A prospective study.


METHODS
A laboratory.


METHODS
Anesthetized, mechanically ventilated dogs (n = 69).


METHODS
The pericardial space was infused with 2.5 or 5 mL of 1% lidocaine, 5 mL of 2% lidocaine, or normal saline solution. The hemodynamic changes and the cardiac responses to atropine or isoproterenol were measured during cardiac nerve blockade. To examine the inhibitory action of pericardial lidocaine on arrhythmias, an electrical fibrillator was installed. Furthermore, the blood level of lidocaine was measured.


RESULTS
Pericardial injection of lidocaine significantly decreased heart rate without a change in stroke volume. Under pericardial lidocaine, the tachycardia response to isoproterenol was similar to that observed without pericardial lidocaine, but response to atropine was significantly reduced. Pericardial lidocaine increased the voltage thresholds for inducing arrhythmias and ventricular fibrillation. Intravenous injection of lidocaine elevated the plasma concentration of lidocaine immediately, whereas the plasma concentration peaked at 10 minutes after pericardial administration.


CONCLUSIONS
Pericardial lidocaine (1) decreased heart rate without affecting stroke volume, (2) preserved the tachycardiac response to isoproterenol but completely blocked the response to atropine, and (3) increased the voltage thresholds for arrhythmias and ventricular fibrillation induced by an electrical fibrillator. These results suggest that pericardial lidocaine may be useful for controlling heart rate during off-pump coronary artery bypass graft surgery.
Takada
Motoshi
M
Department of Anesthesiology and Pain Medicine, Gifu University Graduate School of Medicine, Gifu, Japan. mtakada_md@ybb.ne.jp
Dohi
Shuji
S
Akamatsu
Shigeru
S
Suzuki
Akira
A
D000758:Anesthesia; D000818:Animals; D047549:Coronary Artery Bypass, Off-Pump; D004285:Dogs; D005283:Fentanyl / Q000494:pharmacology*; D006339:Heart Rate / Q000187:drug effects*; D008012:Lidocaine / Q000494:pharmacology*; D008874:Midazolam / Q000494:pharmacology*; D010496:Pericardium / Q000187:drug effects*; D013318:Stroke Volume / Q000187:drug effects*; D014693:Ventricular Fibrillation / Q000209:etiology
D008012:Lidocaine; D008874:Midazolam; D005283:Fentanyl