BACKGROUND: The authors describe haemodynamic changes secondary to controlled and induced hypotension during anesthesia with different halothane concentrations. METHODS: Twenty-nine New Zealand white rabbits (Oryctolagus cuniculus) were divided into four groups. A control group, composed by five animals, was compared to groups I, II, and III, with eight rabbits each one (n=8), that underwent anesthesia with halothane in concentrations of 1,0%, 1,5% and 2,0% respectively. Cardiac and respiratory rates, body temperature, average arterial blood pressure, pH values, arterial oxygen tension (PaO2), arterial carbon dioxide tension (PaCO2), bicarbonate concentrations (-HCO3), base excess (BE), and haemoglobin oxygen saturation (Sat O2) were studied. All parameters were registered before, during and after halothane anesthesia induced hypotension. Corneal and pupilary reflexes and cardiogram were followed continuously. RESULTS: Halothane resulted in hypotension and reduced heart rate. Rabbits have an alcaline blood pH. The metabolic acidosis trend observed was of transient character. Halothane did not modify SatO2.. CONCLUSION: Halothane is a safe and efficient anaesthetic to promote induced or controlled hypotension in rabbits.
Anesthesia; Halothane; Hypotension, controlled; Rabbits
