Comparison of bispectral index and vital parameters in rabbits receiving propofol or isoflurane anesthesia / Comparison of bispectral index and vital parameters in rabbits receiving propofol or isoflurane anesthesia

ABSTRACT

Background: Reflexes, muscle tonus, heart rate, respiratory frequency and blood pressure are parameters that can be used to evaluate the depth of anesthesia. Bispectral index (BIS) was developed with the objective of evaluating quantitatively the sedative and hypnotic effects of anesthetic drugs. It is widely used to assess central nervous system depression levels. The objective of this study was to compare changes in BIS and several vital parameters during general anesthesia achieved with either propofol or isoflurane, following premedication with dexmedetomidine. Materials, Methods & Results: Adult female New Zealand rabbits (Mean ± SD body weight 3.6 ± 0.4 kg) were procured from a commercial source certified for medical experimentation. The animal number in each of the two study groups was four, for a total of eight. The animals were checked before the study to ascertain their good health. The animals, randomly allocated to either of two study groups, were given dexmedetomidine, 20 µg/kg i.v. Induction was realized by means of propofol, 8 mg/kg i.v. in the propofol group (n = 4), and by administration through a glove mask of isoflurane, 4%, in the isoflurane group (n = 4). Anesthesia maintenance was assured by propofol, 0.6 mg/kg/min or 2% isoflurane with oxygen, respectively. Both anesthetic applications were well tolerated by the rabbits. Before premedication (T0), at

RESUMO

Background: Reflexes, muscle tonus, heart rate, respiratory frequency and blood pressure are parameters that can be used to evaluate the depth of anesthesia. Bispectral index (BIS) was developed with the objective of evaluating quantitatively the sedative and hypnotic effects of anesthetic drugs. It is widely used to assess central nervous system depression levels. The objective of this study was to compare changes in BIS and several vital parameters during general anesthesia achieved with either propofol or isoflurane, following premedication with dexmedetomidine. Materials, Methods & Results: Adult female New Zealand rabbits (Mean ± SD body weight 3.6 ± 0.4 kg) were procured from a commercial source certified for medical experimentation. The animal number in each of the two study groups was four, for a total of eight. The animals were checked before the study to ascertain their good health. The animals, randomly allocated to either of two study groups, were given dexmedetomidine, 20 µg/kg i.v. Induction was realized by means of propofol, 8 mg/kg i.v. in the propofol group (n = 4), and by administration through a glove mask of isoflurane, 4%, in the isoflurane group (n = 4). Anesthesia maintenance was assured by propofol, 0.6 mg/kg/min or 2% isoflurane with oxygen, respectively. Both anesthetic applications were well tolerated by the rabbits. Before premedication (T0), at