Pulmonary function testing in the intensive care unit

A number of tests of pulmonary function have been successfully developed for use in the intensive care unit. When performed in the ICU on critically ill patients, many of the traditional laboratory-based tests will have different clinical implications than when performed in ambulatory patients, for example vital capacity measurement. Also, the clinical questions posed in the ICU are often different, such that estimates of lung water may be clinically more useful than more traditional measures, such as the flow-volume loop. There is a need for further research to identify the clinical utility of these measurements. As the understanding of ARDS and MOF improves, new therapies may be developed which will require sensitive methods in order that they can be evaluated accurately. Similarly, the potential for new methods of respiratory support such as jet ventilation, extracorporeal techniques and lung transplantation reinforce the need for the pulmonary physician to be able to make an accurate assessment of respiratory function on the intensive care unit.