Determination of the minimum alveolar concentration (MAC) of sevoflurane in puppies (neonates and canine pediatrics)

• Grant number: 05/02134-8
• Support Opportunities: Regular Research Grants
• Start date: January 01, 2006
• End date: December 31, 2007
• Field of knowledge: Agronomical Sciences - Veterinary Medicine
• Principal Investigator: Valéria Nobre Leal de Souza Oliva
• Grantee: Valéria Nobre Leal de Souza Oliva
• Host Institution: Faculdade de Odontologia (FOA). Universidade Estadual Paulista (UNESP). Campus de Araçatuba. Araçatuba , SP, Brazil

Abstract

In the literature we researched certain difficulty could be noted in the determination of the exact period for the classification of canine patients in neonates and pediatrics. However, it is known that until 6 weeks of age these animals have very immature respiratory, cardiovascular, hepatic, and renal systems. Because of these physiological differences and the shortage of studies to determine the minimum alveolar concentration of sevoflurane in puppies it is needed to accomplish these works to concur with Veterinarian Anaesthesiology in these patients. This work is aimed to determine the minimum alveolar concentration (MAC) of sevoflurane in young dogs, divided in different age groups. Ten baby dogs will undergo inhalant anaesthesia with sevoflurane in the ages of 30, 45, 60, 120 and 180 days. The checkup will include electrocardiography in dII derivation, mean invasive arterial blood pressure (transcutaneous catheterization of the femur artery, with catheter and aneroid air-gauge connection), pulse oximetry, arterial blood gas and rectal temperature, sevoflurane amount (ETsev) and carbon dioxide (ETCO2) in the end of the expiration. Sevoflurane concentration in the end of the expiration will be used keeping in 1.5 MAC for at least 15 minutes for the accomplishment of the pain stimulus. With the initial concentration of 1.5 MAC, dogs will be stimulated with electricity of 50V and 5Hz/0.9ms. Electrical stimulation will be induced with needles placed on the middle third of the left and right metatarsus, alternately, during 60 seconds or less, occuring positive reaction. When the reaction to the first stimulation is negative, sevoflurane concentration will be decreased in 80% of its initial concentration (1.5 MAC), as well as the stimulus will be repeated after 15 minutes, in order to stabilize the circuit. Whether in the beginning the answer is positive, the anaesthesic concentration is increased in 20% and after 15 minutes a new stimulation is tried... (AU)