Gangrene in Behcet's syndrome.

Abstract

It is regrettable that P.E.F.measure- ments continue ito be popular among clini- cians,' despite warnings about their relative lack of sensitivity in assessing airway obstruc- tion published in your columns years ago.2'More recent studies which have clarified the relationship between lung volume, expiratory flow rate, and alveolar pressure' 5 substanti- ate the view that "The measurement of the maximal expiratory flow rate . . .cannot be recommended as a single lung function test."'Maximum expiratory flow rates depend on lung volume, and flow rates at small lung volumes are more depressed under conditions of peripheral airway obstruction than P.E.F.5 7 ' Leuallen and Fowler' realized this fact long ago, when they introduced the measurement of mid-expiratory flow rate.Measurement of spirometric values such as the F.E.V.1 or mid-expiratory flow rate, or recordings of maximum expiratory flow- volume curves, all include, directly or indirectly; information on maximum flows occurring at smaller lung volumes than that at which P.E.F. is reached.Any one of these methods would have indicated the severity of the persistent airway obstruction in the patient of Dr. Gregg and Dr. Batten more adequately than P.E.