Comparison of Cardiopulmonary Parameters in awake and anesthetized chickens

Steady state cardiovascular and respiratory parameters in adult male chickens while they were awake and after anesthetization with a mixture of chloral hydrate, magnesium sulfate, and pentobarbital were compared. Blood pressure (BP), heart rate (HR), cardiac output (CO), stroke volume (SV), peripheral resistance (TPR), tidal volume (VT), respiratory rate (RR), minute ventilation (V), end-experatory carbon dioxide partial pressure (PACO2), and arterial blood gases and pH were measured simultaneously on birds spontaneously breathing air. Anesthetization resulted in increased HR and RR and decreased BP, CO, TPR, VT, PACO2, and blood gas tension. The data indicate a depression of cardiovascular function but no change in total ventilation although the relative contributions of VT and RR were changed. Anesthetization increased variability in SV although the other parameters were maintained in a steady-state condition over a 2-h period.