Recent advances in mechanical ventilation.

have their origins in the polio epidemics of the 1950s which were associated with a high incidence of respiratory failure. During this period, two important aspects of critical care were firmly established: • mechanical ventilatory support (both invasive and non-invasive) could improve survival in respiratory failure, and • ventilatory support was better provided by dedicated specialist units. Since the 1960s, the ability to provide invasive mechanical ventilation has continued to define intensive care unit (ICU) care and in most units at least 50% of admissions will receive such support. Until recently, the exclusive use of ventilators in ICUs (and theatres) promoted an understandable view that most general physicians needed little working knowledge of these devices. However, the development of non-invasive ventilation (NIV) on medical wards, as well as the widespread use of continuous positive airway pressure (CPAP), has significantly altered the situation. A basic understanding of ventilator and CPAP technology is now important to all those caring for the acutely ill. This article will provide a brief explanation of ventilatory modes and then review ventilatory support in two common conditions that cause respiratory failure on the ICU: • adult respiratory distress syndrome (ARDS), and • chronic obstructive pulmonary disease (COPD).