Blood gas and acid-base status during tiletamine/zolazepam anaesthesia in dogs.

Abstract

OBJECTIVE:

To evaluate the effect of the tiletamine/zolazepam (TZ) combination (Zoletil 100; Virbac, Carros, France) with and without atropine on blood gas values and acid-base status in dogs.

STUDY DESIGN:

Randomized cross-over experimental study.

ANIMALS:

Six healthy adult cross-bred dogs, weighing 11.0-18.5 kg.

MATERIALS AND METHODS:

Each dog received four different drug treatments at intervals of at least 15 days: (i) 5 mg kg(-1) intravenous (IV) TZ (TZ.IV); (ii) 10 mg kg(-1) intramuscular (IM) TZ (TZ.IM); (iii) atropine, 20 microg kg(-1) IV, followed 5 minutes later by 5 mg kg(-1) TZ IV (A.TZ.IV); and (IV) atropine (same dose) given 5 minutes before 10 mg kg(-1) TZ IM (A.TZ.IM). Arterial blood samples were collected from each dog before drug administration (baseline) at induction of anaesthesia (time 0) and 2, 5, 10 and 30 minutes thereafter.

RESULTS:

Transient hypoxaemia and respiratory acidosis were observed just after induction. PaO(2) and SaO(2) dropped, while H(+) concentration and PaCO(2) rose significantly above baseline values. In groups TZ.IV and A.TZ.IV, PaO(2) values as low as 6.0-6.4 kPa (45-48 mm Hg) were recorded. However, there was no significant difference in blood gas variables among the groups encountered during the evaluation period. The overall change in [HCO(3) (-)] and base excess (BE) was not significant among groups. Atropine did not affect the above variables.

CONCLUSIONS AND CLINICAL RELEVANCE:

Tiletamine/zolazepam injection may induce transient hypoxaemia and respiratory acidosis, but acid-base status changes are clinically unimportant. Particularly, close observation of dogs is recommended during the first 5-10 minutes after induction with TZ, especially in animals with cardiopulmonary disease. TZ should perhaps not be used in animals intolerant of tachycardia.

• Authors: Ioannis Savvas, Katerina Plevraki, Dimitris Raptopoulos, Alexandros F Koutinas
• Journal: Veterinary anaesthesia and analgesia (Vet Anaesth Analg) Vol. 32 Issue 2 Pg. 94-100 (Mar 2005) ISSN: 1467-2987 [Print] United States
• PMID: 15762914 (Publication Type: Clinical Trial, Journal Article, Randomized Controlled Trial)

Chemical References

• Anesthetics, Dissociative
• Carbon Dioxide
• Tiletamine
• Zolazepam
• Oxygen

Topics

• Acidosis (veterinary)
• Anesthesia, Intravenous (veterinary)
• Anesthetics, Dissociative (administration & dosage)
• Animals
• Blood Gas Analysis (veterinary)
• Carbon Dioxide (blood)
• Cross-Over Studies
• Dogs (physiology)
• Female
• Hydrogen-Ion Concentration
• Male
• Oxygen (blood)
• Tiletamine (administration & dosage)
• Treatment Outcome
• Zolazepam (administration & dosage)