Conventional mechanical ventilation

Mechanical ventilation has become a very common and well-accepted practice in modern intensive care units. The use of the mechanical ventilator has progressed from being a support system during surgery and for acutely ill patients to being used in both moderate and long-term life support in patients with inadequate ventilation. The sophistication of modern ventilators and the ability of trained respiratory therapists and nursing personnel have permitted this technology to explode. This is occurring at a time when there are still many controversies about the relative benefits and modes of action of conventional ventilation. As newer techniques are developed, it is mandatory that the application of these techniques be tempered with controlled clinical trials, documenting their effectiveness. The beneficial effects of new modalities must be documented as mechanical ventilation expands from use in the intensive care unit to use in standard medical wards and the patient's home. In these latter two settings, the vigilance of an intensive care unit is absent and the simplest method will be preferable. The requirement to demonstrate efficacy of new techniques with adequate studies is especially necessary now as the economics of health delivery have come under increasing scrutiny. Even more important than new technologies may be the efficacy of prolonged mechanical ventilation. A recent study by Spicher and White evaluated the outcome in 250 patients ventilated for 10 days or more at the Hershey Medical Center (Pennsylvania State University). The mortality, morbidity, and disability in patients in this study population requiring prolonged ventilation were extremely high. As these studies have pointed out, further evaluations of predictors of meaningful survival are necessary to avoid unnecessary human suffering and to best use limited resources.