File name: Flow-Volume Loop Interpretation Pdf

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👉Flow-Volume Loop Interpretation Pdf

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Flow-volume measurement Basic spirometry volume-time curve Flow-volume curve expiratory flow rate plotted against the volume of air exhaled Overall shape of flow-volume curve detects . Flow-Volume (F-V) loop is the most important curve in spirometry. A normal F-V loop (Fig. 1, Fig. 2) begins on the X-axis (Volume axis): at the start of the test both flow and volume are equal to . Note that there are 3 separate flow-volume loops all superimposed on one graph. This is typical for office spirometry. A patient may be normal by comparison to one database but be mildly or . Determination of Flow-Volume loop Fig. 1, Fig. 2 Flow-Volume (F-V) loop is the most important curve in spirometry. A normal F-V loop (Fig. 1, Fig. 2) begins on the X-axis (Volume axis): at the start of the test both flow and volume are equal to zero. Directly after this starting point the curve rapidly. Approach to pulmonary function test interpretation In obstructive disease, forced expiratory volume in the first second is decreased (FEV1). Expiratory flow in the latter two-thirds of expiration are effort independent and vary directly with elastic recoil of the lung and inversely with airway resistance. In COPD elastic recoil is decreased due. •Peak expiratory flow (PEF) is reduced •decline in airflow to complete exhalation follows a distinctive concave curve Severe obstructive disorder •In severe airflow obstruction characteristic ‘steeple pattern’ in expiratory flow trace Restrictive disorder •Pattern in expiratory trace normal in shape but absolute reduction in volume. Inspiratory time is shortest for Square wave flow form. Least Peak inspiratory pressures (19% decrease). High mean airway pressure, helps lung inflation and oxygenation. FLOW STARVATION. Should not be used in assist modes. Usually preferred as the initial flow rate meets the flow demand of the patient. Decreases air hunger. • Electronic - flow-volume curve • Calculate %age predicted normal values • Reports - defects, severity. Spirometry Interpretation 1. Determine if the flow-volume loop appears acceptable 2. Determine if the patient is obstructed by whether the FEV1/FVC ratio is below normal 3. If the patient is obstructed, determine how severe the obstruction is by how far below normal the FEV1 is Defining obstruction • Obstruction is present if the FEV1/FVC.