The cardiopulmonary effects of sevoflurane, isoflurane and halothane anesthesia during spontaneous or controlled ventilation in dogs

The objective of this study was to investigate the cardiopulmonary effects of sevoflurane (SEV), isoflurane (ISO) and halothane (HAL) anesthesia during spontaneous ventilation (SV) or controlled ventilation (CV) in dogs. An experimental study was designed. Sixty healthy cross breed dogs were used for the study. Dogs were randomly allocated to six anesthesia groups (n = 10 in each group): SEV/SV; SEV/CV; ISO/SV; ISO/CV; HAL/SV; HAL/CV. After premedication with xylazine HCl, anesthesia was induced with thiopental sodium. Inhalation anesthesia was maintained for 90 minutes with SEV, ISO, or HAL. Cardiopulmonary parameters [heart rate (HR), respiratory rate (RR), mean arterial blood pressure (MAP), end tidal carbon dioxide level (ETCO2), oxygen saturation (SpO(2)), central venous pressure (CVP), body temperature, arterial partial pressure of oxygen (PaO2), arterial partial pressure of carbon dioxide (PaCO2), and arterial pH] were measured after induction of anesthesia; the first measurement was taken one minute after the loss of consciousness with SEV, ISO, or HAL and the others were done at 15th, 30th, 45th, 60th and 90th minutes. There was not any significant difference in HR between anesthetics among SV and CV. RR decreased significantly during ISO and HAL anesthesia in SV (p < 0.001). MAP decreased significantly in all groups but there was not any significant difference between the ventilation modes. There was a significant decrease in ETCO2 during CV compared to SV (p < 0.001). The CVP values during anesthesia with SEV in SV were lower than those of other anesthetics (p < 0.001). Body temperature decreased significantly during ISO and HAL anesthesia compared to SEV anesthesia (p < 0.001). Compared with SV, CV prevented the increase in PaCO2 (p < 0.001) and no decrease in pH was observed (p < 0.05). It is concluded that SEV anesthesia was appeared to have minimum complications on cardiopulmonary parameters in the healthy dogs which were premedicated with xylazine HCL and inducted with thiopental sodium. In the study, the use of CV was not associated with cardiovascular embarrassment during inhalation anesthesia and it was provide a more stable plane of anesthesia