High Altitude Case Study On Anaesthetic Effects Of Xylazine/Ketamine During Surgery In Ladakhi Dog.

Sudhakar Natarajan* N. S.Jadon*

Indo Tibetan Border Police, C/O 56 APO G B Pant Univ.,Pantnagar

* Veterinary Officer, 18 Bn, ITBP, Ladakh Sector. * Assoc Professor, Surgery&Radiology

Introduction: Agents that cause an adequate depth of anaesthesia are pivotal during surgery and they should have adequate analgesic activity, a wide margin of safety, sufficient depth of anaesthesia to fecilitate surgical manipulations and recovery should be smooth devoid of any undesirable complications.

Objective: This endeavour was undertaken in the high altitude cold desert terrain of Ladakh, so as to study the anaesthetic manifestations of xylazine/ketamine combination during surgical manipulations , at approx 11000 feet above mean sea level, where low partial pressure of oxygen , low ambient temperature and relative humidity have a palpable effect on body functioning and physiological responses( QMG, 1988).

Case: A healthy Ladakhi dog, aged approx 3 years and weighing 17 Kgs was used in this study to evaluate the anaesthetic efficacy of xylazine and ketamine combination, administered intramuscularly, @ 1 mg/kg b.wt. and 5 mg/kg b.wt. , respectively ( Mones and Fargetton,1990) . Pre-medication was done using atropine sulphate @ 0.44 mg/kg b.wt. ( Viana and Osswald,1971 ; Kumar,1977)

The subject was administered with atropine sulphate 5 minutes prior to administration of anaesthetic. Subsequently xylazine/ketmine combination was administered intramuscularly at the dose rates elucidated in the above paragraph.

Results: The weak time, that was calculated from the time taken from the administration of the drug to the onset of inco-ordination was 3.5 minutes. The down time, that was gauged by recording the time taken from the administration of drug to the onset of lateral or sternal recumbancy, was 6.0 minutes. Duration of anaesthesia, that was calculated from the loss of pin-prick /pedal reflex to their return, was observed to be 32 minutes.

It was also observed that the cardiopulmonary depression caused by an alpha2 agonist like xylazine was not very marked due to atropine premedication. ( Kandpal and Kumar,1998; Grimm et al , 1998). The effect of this combination on the heart rate, respiration and temperature have been depicted graphically. The readings were taken at 5 minutes interval.

High Altitude Case Study On Anaesthetic Effects Of Xylazine/Ketamine During Surgery In Ladakhi Dog.



`

A decrease in the heart rate was observed 5 minutes after administration of xylazine/ketamine. There was a increase in the heart rate till the 20th minute and thereafter it decreased and reached preadministration levels.

There was a decrease in the respiration rate till the 25th minute and after that it gradually increased till it reached normal values.

A slight and gradual decrease in the rectal temperature was observed till 15 minutes. Then from 25 minutes it gradually increased to reach near preadministration levels.

The midline incision during lapratomy and scrotal incision made for castration , elicited no pain response from the animal. Surgical manipulations during handling of viscera, ligation, suturing and various surgical procedures were conducted smoothly, without any complications. The dog recovered uneventfully.

Discussion: Initial bradycardia followed by tachycardia after administration of alpha 2 adrenoceptor drugs simulates the observations of Alibhai et al (1996) and Pratap et al (1997) . This also agrees with the study of Ameerjan, 1993 and Arnemo and Soli,1993 who used xylazine in cattle. The appreciable dip in the heart rate may have been due to the effects of high altitude coupled with the cardiac depression caused by xylazine. Tachycardia observed after initial bradycardia may be due to prior administration of atropine ( Vainio and Palmu,1989) which transiently abolished the bradycardiac effects of the alpha2 adrenoceptor drug in dogs. The decrease in the respiratory rate is in accordance with the observations of Tiwari 1996. The tachycardia seen can be linked to the respiratory depression, as it could be a compensatory mechanism to the decreased oxygen perfusion in the body coupled with the low partial pressure of oxygen in high altitudes(QMG, 1988). Slight hypothermia has also been observed on administration of other alpha2 agonist drugs by Cullen, 1996.

Summary: The above combination of xylazine and ketamine , with atropine premedication in dog, caused a rapid onset of anaesthesia in high altitude and provides a sufficiently long duration of surgical analgesia. The high altitude variables of low partial pressure of oxygen, low ambient temperature and relative humidity did not have any appreciable effect on the depth of anaesthesia and subsequent post-surgical recovery of the subject. The recovery was devoid of any complications and was smooth.

Acknowledgements: Gratitude is expressed to Dy Inspector General(Ladakh) for constant encouragements and Commandant 18th Bn, for extending requisite facilities. Thanks are also due to Hav/vet Narender Singh and Hav/AT Om Parakash for their technical assistance.

References:

Alibhai,H.I.K.; Clrke,K.W. ; Lee, Y.H. and Thompson, J. 1996.Cardiopulmonary effects of the combination of medetomidine hydrochloride and atropine sulphate in dogs. Veterinary Record.138(1):11-13.

Ameerjan,K.1993. Studies on cardiopulmonary, haematological ,biochemical and histopathological changes of Ketamine/Xylazine anaesthesia in calves.(Abstract).Indian J. Vet. Surg. 14(1):44-77

Arnemo,J.M. and Soli N.E. 1990. The use of xylazine(Rompun) for epidural anaesthesia in cattle. Norsk-Veterinaer Tidsskrift. 102(8-9): 583-584

Cullen,L.K.1996. Medetomidine sedation in dogs and cats.British Veterinary Journal.152(5):519-535.

Grimm,K.A.; Thurmon,J.C.; Olson,W.A.; Tranquili,W.J.; Benson,G.J. 1998.The pharmacokinetics of thiopental,medetomidine,butorphenol and atropine in beagle dogs. Journal of Veterinary Pharmacology and Therapeutics. 21(2): 133-137.

Kandpal,M.; Kumar,A. 1998. Ketamine with and without diazepam or detomidine premedication in bovine paediatric patients.Indian J. Anim. Sc. 68(9) : 904-906

Kumar,A.1977. Cardiovascular, respiratory and biochemical effects of atropine sulphate.Indian Vet. J. 54 : 29-32

Mones,Y.; Fargetton,X.1990. A comparative study of medetomidine/ketamine and xylazine/ketamine anaesthesia in dogs. Veterinary Record. 127(23): 567-571

Pratap,K.; Amarpal; Aithal,H.P. and Singh, G.R. 1997. Effects of medetomidine injection in dogs.Indian Veterinary Journal.74(7):627

QMG.1998. Management of animals in high altitude areas. Handbook of Animal Mgt.140-143

Tiwari,S.K.1996. Clinico-cardiopulmonary and haematobiochemical effects of alpha2 agonists with and without local anaesthesia and their reversal in buffaloes. Indian J. Vet. Surg. 17(2):137,

Viana,A.P. and Osswald,W. 1971. Arrythmic action of atropine. Arch.Int. Pharmacodyn.Ther. 192 : 238-246

Vainio,O. and Palmu,L.1989. Cardiovascular and respiratory effects of medetomidine in dogs and influence of anticholinergics. Acta Veterinaria-Scandinavica.30(4):401-405.