Abstract
Respiratory mechanics refers to the expression of lung function through measures of pressure and flow. From these measurements, a variety of derived indices can be determined, such as volume, compliance, resistance, and work of breathing. Plateau pressure is a measure of end-inspiratory distending pressure. It has become increasingly appreciated that end-inspiratory transpulmonary pressure (stress) might be a better indicator of the potential for lung injury than plateau pressure alone. This has resulted in a resurgence of interest in the use of esophageal manometry in mechanically ventilated patients. End-expiratory transpulmonary pressure might also be useful to guide the setting of PEEP to counterbalance the collapsing effects of the chest wall. The shape of the pressure-time curve might also be useful to guide the setting of PEEP (stress index). This has focused interest in the roles of stress and strain to assess the potential for lung injury during mechanical ventilation. This paper covers both basic and advanced respiratory mechanics during mechanical ventilation.
- auto-PEEP
- chest wall
- compliance
- esophageal pressure
- mechanical ventilation
- plateau pressure
- resistance
- respiratory mechanics
- work of breathing
Footnotes
- Correspondence: Dean R Hess PhD RRT FAARC, Respiratory Care Services, Ellison 401, Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114. E-mail: dhess{at}partners.org.
Dr Hess discloses relationships with Philips Respironics, Pari, Covidien, Maquet, Merck, Bayer, McGraw-Hill, Jones and Bartlett, and UpToDate.
Dr Hess presented a version of this paper at the 29th New Horizons in Respiratory Care Symposium: Back to the Basics: Respiratory Physiology in Critically Ill Patients at the 59th AARC Congress, held November 16–19, 2013, in Anaheim, California.
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