title: Ventilatory effects produced by the i.v. administration of incremental doses of thiopentone in the dog.
abstract: Ventilation, ventilatory pattern and ventilatory drive were studied in five dogs during the administration of increasing blood concentrations of thiopentone. Ventilation (VE, RR, VT) and blood-gas tensions (pHa, PaCO2, PaO2,) were measured. Ventilatory pattern (VT, TI, TE, Ttot) and ventilatory drive (VT/TI) and occlusion pressure) were analysed. Occlusions of the airway were performed at end-inspiration and at end-expiration. Thiopentone produced a biphasic action on respiratory rate, ranging from tachypnoea during light anaesthesia to a progressive slowing of respiration with deepening anaesthesia. The Hering-Breuer reflex did not seem to be modified by the level of anaesthesia, whereas the central mechanisms which modulate the duration of inspiration and of expiration, were perturbed.
mesh_terms: D000771:Anesthesia, Intravenous; D000818:Animals; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D008168:Lung / Q000187:drug effects / Q000503:physiopathology; D008297:Male; D011659:Pulmonary Gas Exchange / Q000187:drug effects; D012018:Reflex / Q000187:drug effects; D012119:Respiration / Q000187:drug effects*; D013874:Thiopental / Q000008:administration & dosage / Q000494:pharmacology*
chemical_list: D013874:Thiopental