Ventilatory support in patients with ARDS.

Abstract

Adult respiratory distress syndrome remains one of the most lethal conditions treated in surgical and medical intensive care units. Mortality rates of 50 per cent are still reported in recent reviews. Many risk factors are linked with an increased incidence of ARDS, but sepsis and direct pulmonary injury from aspiration, pulmonary contusion, and other forms of trauma are the most commonly associated risk factors. Studies implicate various cellular and chemical mediators associated with acute lung injury. Many pharmacologic agents and various forms of high-frequency ventilation are being studied for their effectiveness in treating ARDS. We consider that the standard treatment continues to be PEEP and mechanical ventilation to reverse hypoxemia linked with the pathophysiologic changes of ARDS. There are no prospective randomized studies comparing the various end points of therapy used clinically at present. We believe, however, that early intervention, with institution of ventilatory support as soon as signs of acute respiratory failure develop, may eliminate some deaths due to progressive hypoxemia leading to the full adult respiratory distress syndrome. Therapy should be started at this time and maintained while the etiologic factors are identified and treated. Minimal ventilatory support should be continued until the primary diseases have resolved and the multisystem impact of the critical illness has lessened. Weaning from inspiratory (IMV) support, manipulation of expiratory pressures (PEEP), and airway control should then be more easily accomplished and more successful in practice.