招待講演１："The airway in burns - What should we do?" Peter Nightingale, M.D. Director, Intensive Care Unit Honorary Lecturer, University Department of Anaesthesia University Hospital of South Manchester West Didsbury, Manchester M20 2LR, England ５月13日(水)　10:30〜11:20 司会：杉本 壽(大阪大学救急医学)

Inhalational burns are an increasing problem in patient management on the Intensive Care Unit. They may occur with or without cutaneous injury, and are probably more common than realized. Many factors can be recognized in the history and examination that are associated with the presence of an inhalational injury, these should be sought and may help identify the level of injury. 　　There are a number of toxic products of combustion of which the most important practically is carbon monoxide. Other agents include hydrogen chloride and phosgene, cyanide, aldehydes and acreolin. As well as damage due to heat, deposition of smoke particles in the lower airway can lead to on-going injury. 　　The presence of an inhalational injury approximately doubles the mortality following a cutaneous burn, and yet therapy remains essentially supportive. The early management of these patients includes a high inspired oxygen concentration and perhaps, if available, the use of hyperbaric oxygen. Treatment for cyanide poisoning may also need to be considered. 　　A careful assessment of the upper airway and tracheobronchial tree needs to be made. Decisions about securing the airway should be made early and the appropriate technique used. This is may include inhalational induction of anaesthesia or an awake fibreoptic technique. 　　Bronchoscopic examination will reveal the extent of the damage to the proximal airways. However, this may not reflect the severity of the lung injury, need for prolonged ventilation, or mortality. The role of mechanical cleaning of the airways remains to be clarified. 　　Prolonged ventilatory support is commonly required because of the acute respiratory distress syndrome (ARDS) which almost inevitably follows smoke inhalation. Over the last few years knowledge and appreciation of the pathophysiology of ARDS has lead to the recognition that mechanical ventilation may be harmful to the lung. A number of ventilatory strategies have evolved to try and reduce this iatrogenic damage. There is some evidence that use of so-called lung protective ventilatory strategy will reduce ventilator associated lung injury and improve hospital mortality. 　　The role of adjuvant therapies are less clear. There is little evidence that any influence outcome, and the mainstay of treatment is to close the burn as soon as possible. 　　Important lessons have been learnt and must be remembered e.g. the increased fluid requirements when an inhalational injury is present. In view of the known limitations of assessment of intravascular volume status in the critically ill patient, the use of invasive monitoring to optimize oxygen transport indices may need to be considered.