An experimental study of pulmonary damage associated with intravenous injection of halothane in dogs

Holothane was injected intravenously into two groups of dogs and the effects on the lungs noted. The nine dogs of group I were unanaesthetized and received no ventilatory support following injection. The dogs were killed at varying time intervals after injection and the macroscopic and microscopic appearances were studied. In the six dogs of group II the the chests were open and they were artificially ventilated with 30 per cent oxygen and 70 per cent nitrous oxide at the time of injection. Serial biopsies were taken. The predominant lesions produced were generalized oedema and patchy alveolar haemorrhages. These changes were more severe in dogs of group I. The aetiology is conjectural, possibly being due to direct capillary damage or to embolization. The danger of accidental intravenous injection of halothane, a not unknown occurrence, is stressed (AU)

The microanatomy of the alveolar duct system

Observations made on wet and dry slices of inflated human lungs taken at necropsy have been used to give a more complete account of the alveolar duct system, the basic respiratory structure. This includes consideration of the central spiral alveolar duct fibre, which is thought to consist of elastic and collagen, the spiral arrangement of alveoli and the special nature of the terminal alveolus, the interdigitation of alveoli from adjacent alveolar ducts and the arrangement of pulmonary arterioles. This suggests that the alveolar duct system is specifically designed so that changes in volume are not accompanied by changes in alveolar surface area.(AU)