Clinical review: respiratory mechanics in spontaneous and assisted ventilation.
Pulmonary disease changes the physiology of the lungs, which manifests as changes in respiratory mechanics. Therefore, measurement of respiratory mechanics allows a clinician to monitor closely the course of pulmonary disease. Here we review the principles of respiratory mechanics and their clinical applications. These principles include compliance, elastance, resistance, impedance, flow, and work of breathing. We discuss these principles in normal conditions and in disease states. As the severity of pulmonary disease increases, mechanical ventilation can become necessary. We discuss the use of pressure-volume curves in assisting with poorly compliant lungs while on mechanical ventilation. In addition, we discuss physiologic parameters that assist with ventilator weaning as the disease process abates.
Grinnan
Daniel C
DC
Department of Pulmonary and Critical Care, University of Virginia Health System, Virginia, USA. dg6j@virginia.edu
Truwit
Jonathon Dean
JD
D000403:Airway Resistance / Q000502:physiology; D045853:Exhalation / Q000502:physiology; D006801:Humans; D001239:Inhalation / Q000502:physiology; D008170:Lung Compliance / Q000502:physiology*; D012121:Respiration, Artificial / Q000379:methods*; D012128:Respiratory Distress Syndrome / Q000628:therapy*; D015656:Respiratory Mechanics / Q000502:physiology*; D015300:Ventilator Weaning / Q000379:methods; D014939:Work of Breathing / Q000502:physiology