Skip to main content
NCBI home page
Archives of Disease in Childhood. Fetal and Neonatal Edition logoLink to Archives of Disease in Childhood. Fetal and Neonatal Edition
. 2004 Mar;89(2):F174–F176. doi: 10.1136/adc.2002.023937

Accuracy of the volume and pressure displays of high frequency oscillators

J Leipala, S Iwasaki, A Milner, A Greenough
PMCID: PMC1756021  PMID: 14977906

Abstract

Objective: To determine the effect of frequency on the accuracy of volume and pressure displays of high frequency oscillators.

Methods: The effect of frequency on the displayed volume of the Stephanie, Dräger Babylog 8000 Plus, and SLE 5000 oscillators was assessed. A sine wave pump delivered a constant tidal volume at frequencies of 5–15 Hz to the patient manifold of the oscillators. The displayed volumes at each frequency were compared with the delivered volume. The effect of frequency on displayed pressure was assessed by connecting the oscillator's patient manifold to a lung model; three types of oscillator were studied (SensorMedics 3100A, SLE 5000, and Stephanie). Airway pressure was measured from the manifold using a pressure transducer and non-compliant tubing; the pressure measuring system had a flat frequency response to 30 Hz.

Results: The SLE 5000 volume display overread the delivered volume (by about 5%), but was not affected by frequency. At 5 Hz, the Dräger Babylog 8000 Plus and the Stephanie underread the delivered volume (by about 20%). Increasing frequency resulted in a greater discrepancy between the delivered and displayed volume with the Stephanie, but a smaller discrepancy with the Dräger Babylog 8000 Plus. Altering frequency had a small effect (maximum difference 6%) on the relation between the displayed and delivered pressure for all three oscillators.

Conclusion: Frequency affects the accuracy of displayed volumes and, to a lesser extent, displayed pressures of high frequency oscillators. The results emphasise that data displayed by new devices should not be uncritically accepted.

Full Text

The Full Text of this article is available as a PDF (138.5 KB).

Figure 1 .

Figure 1

Open in a new tab

Effect of frequency on the accuracy of the volume display.

Figure 2 .

Figure 2

Open in a new tab

Effect of frequency on the accuracy of the displayed pressure.

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Boynton B. R., Hammond M. D., Fredberg J. J., Buckley B. G., Villanueva D., Frantz I. D., 3rd Gas exchange in healthy rabbits during high-frequency oscillatory ventilation. J Appl Physiol (1985) 1989 Mar;66(3):1343–1351. doi: 10.1152/jappl.1989.66.3.1343. [DOI] [PubMed] [Google Scholar]
  2. Chan V., Greenough A., Milner A. D. The effect of frequency and mean airway pressure on volume delivery during high-frequency oscillation. Pediatr Pulmonol. 1993 Mar;15(3):183–186. doi: 10.1002/ppul.1950150310. [DOI] [PubMed] [Google Scholar]
  3. Courtney S. E., Weber K. R., Spohn W. A., Malin S. W., Bender C. V., Gotshall R. W. Measurement of tidal volume using a pneumotachometer during high-frequency oscillation. Crit Care Med. 1990 Jun;18(6):651–653. doi: 10.1097/00003246-199006000-00015. [DOI] [PubMed] [Google Scholar]
  4. Fredberg J. J., Glass G. M., Boynton B. R., Frantz I. D., 3rd Factors influencing mechanical performance of neonatal high-frequency ventilators. J Appl Physiol (1985) 1987 Jun;62(6):2485–2490. doi: 10.1152/jappl.1987.62.6.2485. [DOI] [PubMed] [Google Scholar]
  5. Hatcher D., Watanabe H., Ashbury T., Vincent S., Fisher J., Froese A. Mechanical performance of clinically available, neonatal, high-frequency, oscillatory-type ventilators. Crit Care Med. 1998 Jun;26(6):1081–1088. doi: 10.1097/00003246-199806000-00032. [DOI] [PubMed] [Google Scholar]
  6. Hoskyns E. W., Milner A. D., Hopkin I. E. Measurement of tidal lung volumes in neonates during high-frequency oscillation. J Biomed Eng. 1992 Jan;14(1):16–20. doi: 10.1016/0141-5425(92)90030-o. [DOI] [PubMed] [Google Scholar]
  7. Johnson Alice H., Peacock Janet L., Greenough Anne, Marlow Neil, Limb Elizabeth S., Marston Louise, Calvert Sandra A., United Kingdom Oscillation Study Group High-frequency oscillatory ventilation for the prevention of chronic lung disease of prematurity. N Engl J Med. 2002 Aug 29;347(9):633–642. doi: 10.1056/NEJMoa020432. [DOI] [PubMed] [Google Scholar]
  8. Pillow J. J., Neil H., Wilkinson M. H., Ramsden C. A. Effect of I/E ratio on mean alveolar pressure during high-frequency oscillatory ventilation. J Appl Physiol (1985) 1999 Jul;87(1):407–414. doi: 10.1152/jappl.1999.87.1.407. [DOI] [PubMed] [Google Scholar]
  9. Pillow J. J., Wilkinson M. H., Neil H. L., Ramsden C. A. In vitro performance characteristics of high-frequency oscillatory ventilators. Am J Respir Crit Care Med. 2001 Sep 15;164(6):1019–1024. doi: 10.1164/ajrccm.164.6.2005008. [DOI] [PubMed] [Google Scholar]
  10. Pillow J. Jane, Sly Peter D., Hantos Zoltan, Bates Jason H. T. Dependence of intrapulmonary pressure amplitudes on respiratory mechanics during high-frequency oscillatory ventilation in preterm lambs. Pediatr Res. 2002 Oct;52(4):538–544. doi: 10.1203/00006450-200210000-00013. [DOI] [PubMed] [Google Scholar]
  11. Scalfaro P., Pillow J. J., Sly P. D., Cotting J. Reliable tidal volume estimates at the airway opening with an infant monitor during high-frequency oscillatory ventilation. Crit Care Med. 2001 Oct;29(10):1925–1930. doi: 10.1097/00003246-200110000-00013. [DOI] [PubMed] [Google Scholar]
  12. Thome U., Pohlandt F. Effect of the TI/TE ratio on mean intratracheal pressure in high-frequency oscillatory ventilation. J Appl Physiol (1985) 1998 May;84(5):1520–1527. doi: 10.1152/jappl.1998.84.5.1520. [DOI] [PubMed] [Google Scholar]
  13. Watson J. W., Jackson A. C. CO2 elimination as a function of frequency and tidal volume in rabbits during HFO. J Appl Physiol Respir Environ Exerc Physiol. 1984 Aug;57(2):354–359. doi: 10.1152/jappl.1984.57.2.354. [DOI] [PubMed] [Google Scholar]

Articles from Archives of Disease in Childhood Fetal and Neonatal Edition are provided here courtesy of BMJ Publishing Group

RESOURCES