A correction formula for computing specific airway resistance from a single-step measurement.

J. Haluszka, G. Willim, R. Cutrera, R. Ronchetti, S. Filtcher

Research output: Contribution to journalArticle


Specific airway resistance (SRaw) is conventionally determined by multiplying the plethysmographically measured values of airway resistance and functional residual capacity (FRC). An alternative single-step method, which avoids the need for airway occlusion during determination of FRC, has been described by Dab and Alexander. The single-step method provides no correction for resistance or dead space of the apparatus and, as a result, systematically overestimates SRaw. Using 1,000 paired measurements, it was possible to compute a formula for correcting the single-step measurement. This correction formula can be adjusted and applied to measurements made in any laboratory. The unlimited applicability of the proposed correction has been demonstrated by 234 plethysmographic measurements made in the Pediatric Clinic in Rome.

Original languageEnglish
Pages (from-to)118-121
Number of pages4
JournalPediatric Pulmonology
Issue number2
Publication statusPublished - 1989


ASJC Scopus subject areas

  • Pediatrics, Perinatology, and Child Health
  • Pulmonary and Respiratory Medicine

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