Respiratory: Measurement of Airway Resistance
摘要
The measurement of respiratory airway resistance is determined by measuring the pressure gradient between the mouth and the alveolus, and dividing this by the flow rate of air as it moves from the atmosphere to the alveolus. There are different methods for measuring this, including direct methods using the body plethysmograph, oscillating airflow, interrupter technique, or end-inspiratory interruption. Indirect methods are discussed in Chapter 19 on spirometry and include peak expiratory flow rate, flow volume loops and expiratory volume-time curves. An assessment of airway resistance can also be made with modern anaesthetic machines, analysing at ventilator patterns.