| We performed single-breath tests in closed-chest, anesthetized dogs. Six dogs with bilateral vagotomy and six dogs with intact vagi were examined. The tests were performed in pairs with heart beating and during cardiac arrest. Repeated cardiac arrest was achieved by ventricular fibrillation and subsequent defibrillation. Twenty-four tests per dog were performed in combinations of three inspiratory volumes (0.2, 0.5 and 0.8 L) and four postinspiratory pauses (0, 5, 10 and 30 seconds) with or without cardiac arrest. Both inspiratory and expiratory flows were 0.2 L/sec. The test gas mixture contained four inert, poorly soluble gases with a six-fold range in diffusivities. Gas concentrations were measured by mass spectrometry. Fowler dead space (V... |
