Tag Archives: PEFR

PEAK EXPIRATORY FLOW RATE

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  • It’s the maximal rate of airflow during forced expiration
  • Dependent on patient-effort
  • Repeated 3 times and the best of the 3 is taken
  • Trends in Peak Expiratory Flow helps to assess the severity status of an acute episode, response to treatment etc
  • Normal values: Females: 250-500 L/min Males:450-700 L/min
  • METHODS TO MEASURE:
  • Wright’s Peak flow meter : Commonly used clinically and is a constant pressure variable orifice device
  • Pneumotachograph : Used for research purposes and is a variable pressure constant orifice device
  • From flow volume loops : They are plots of airflow at various lung volumes. Help to distinguish between obstructive & restrictive devices