Effect of intravenous lidocaine on heart rate, systolic arterial blood pressure and cough responses to endotracheal intubation in propofol-anaesthetized dogs.
OBJECTIVE
To evaluate the effect of intravenous lidocaine on coughing and variations in heart rate (HR) and systolic arterial pressure (SAP) at endotracheal intubation in propofol-anaesthetized dogs.


METHODS
Prospective, randomized, blinded clinical study.


METHODS
Eighty dogs, ASA grades I/II.


METHODS
Dogs were randomly assigned to one of two treatments, with dogs in the lidocaine group receiving 1 mg kg(-1) lidocaine intravenously and those in the saline group receiving 0.05 mL kg(-1) saline intravenously before induction of anaesthesia with up to 6.5 mg kg(-1) propofol intravenously. An electrocardiogram was recorded continuously. Heart rate was calculated and SAP (using Doppler ultrasonic flow detection) was recorded at the following time points: pre-treatment, following lidocaine or saline administration, before and after intubation. The occurrence, number and strength of coughs were recorded. Systolic arterial pressure and HR were compared using one-sample t-tests to examine whether SAP and HR changed with test drug administration or following intubation. The number of coughs was compared between groups using t-tests. A cross tabulation and chi-square or Fisher's exact test was used to compare proportions of dogs that coughed and intensity of coughing in each group. The level of significance was set at p < 0.05.


RESULTS
Heart rate did not change in either group. Systolic arterial blood pressure increased following intubation in both the lidocaine (p = 0.003) and saline groups (p = 0.001). There was no difference in the increase in SAP or in the number or intensity of coughs at intubation between groups.


CONCLUSIONS
Intravenous lidocaine had no effect on the occurrence or intensity of coughing or on changes in SAP at endotracheal intubation in dogs anaesthetized with propofol. The use of 1 mg kg(-1) lidocaine intravenously before intubation in dogs to attenuate cough and the pressor response was not supported.
Jolliffe
Colette T
CT
Centre for Small Animal Studies, Animal Health Trust, Newmarket, UK. colette.jolliffe@aht.org.uk
Leece
Elizabeth A
EA
Adams
Vicki
V
Marlin
David J
DJ
D000758:Anesthesia / Q000662:veterinary*; D018686:Anesthetics, Intravenous / Q000008:administration & dosage; D000779:Anesthetics, Local / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D003371:Cough / Q000517:prevention & control / Q000662:veterinary; D004283:Dog Diseases / Q000517:prevention & control; D004285:Dogs / Q000502:physiology*; D004311:Double-Blind Method; D004562:Electrocardiography / Q000662:veterinary; D006339:Heart Rate / Q000187:drug effects*; D007262:Infusions, Intravenous / Q000662:veterinary; D007442:Intubation, Intratracheal / Q000662:veterinary; D008012:Lidocaine / Q000008:administration & dosage / Q000494:pharmacology*; D011183:Postoperative Complications / Q000517:prevention & control / Q000662:veterinary; D015742:Propofol / Q000008:administration & dosage; D011446:Prospective Studies; D016896:Treatment Outcome
D018686:Anesthetics, Intravenous; D000779:Anesthetics, Local; D008012:Lidocaine; D015742:Propofol