Intermittent positive-pressure breathing.

Why the continued confusion over the issue of intermittent positive-pressure breathing (IPPB) as related to therapeutic benefits? Welch’s’ communication in response to the article by Loren et a12 comparing simple nebulization and IPPB in asthmatic children fails again to identify specific criteria for therapy with IPPB. Welch and Loren are both correct in identifying the ineffectiveness of therapy with IPPB at 10 cm H20, as compared to simple aerosol therapy; however, Welchl relates to tidal volume (TV) as the common indicator. Therapy with IPPB, as compared to Freon-propelled nebulizers, pneumatic nebulizers, ultrasonic nebulizers, etc, is no more effective than any other when relating to a measurement of TV. For years, we have cited as one of the clinical indications for therapy with IPPB that of “deep pulmonary aerosol therapy.”3 “Deep” does not imply volumes at tidal breathing levels. Therefore, the only indication (criterion) for the effective use of therapy with IPPB should be to produce a greater maximal iri.spiratory volume than can be spontaneously produced by the effort of the patient (unassisted). Twenty-three asthmatic children were studied using therapy with IPPB at 10 cm H20 and hand-held Freonpropelled nebulizers. The article by Loren et a12 does not even refer to inspiratory volumes delivered via either method. Undoubtedly, the young patients provided spontaneous inspiratory volumes of equal measurements during both modes of therapy; and, therefore, IPPB was not even indicated as a method of improving upon therapeutic response to bronchodilator therapy. We continue to relate therapy with good old IPPB to pressure in centimeters of water, instead of inspiratory volume, and compare IPPB to methods with entirely different criteria. Pressure is only being used as the means of attaining increased volume and, unless volumes are directly measured, is the only measurable means of adjusting therapy. When we begin to use “volume” as the quantitative measurement, we will then be able to justify the continued use of therapy with IPPB for specific clinical conditions, ie, the inability of the patient to spontaneously take a deep breath.