Cardiovascular–Respiratory Activity During Recovery from Anesthesia and Surgery in Brook Trout (Salvelinus fontinalis) and Carp (Cyprinus carpio)

Brook trout (Salvelinus fontinalis) and carp (Cyprinus carpio) were subjected to handling, anesthesia, and extensive experimental pretreatment, including the emplacement of electrocardiograph electrodes and of buccal, cleithral, dorsal aortic, and urinary bladder catheters. Determination of oxygen consumption, cardiac and ventilatory rates, and rate ratios, ventilatory flow, ventilatory stroke volume, and gross oxygen utilization were subsequently carried out at intervals over a 26-hr postpreparation period. Four general patterns of functional variation were observed during recovery. In the most common pattern, activity changed steadily to a final value. Other patterns were characterized by an initial lag phase or intermediate maximum, minimum, or plateau values prior to apparent stabilization. Brook trout required longer than carp for recovery, and differed from carp in the relationship between ventilation and oxygen utilization during recovery. Provision for recovery periods of not less than 24 hr is recommended for studies involving preexperimental preparations of the type studied.