Intensive Care Medicine

, Volume 31, Issue 9, pp 1255–1261

Reliability of measured tidal volume in mechanically ventilated young pigs with normal lungs

  • Mark J. Heulitt
  • Shirley J. Holt
  • Tracy L. Thurman
  • Renée A. Hall
  • Chan-Hee Jo
  • Pippa Simpson
Pediatric Original

DOI: 10.1007/s00134-005-2717-y

Cite this article as:
Heulitt, M.J., Holt, S.J., Thurman, T.L. et al. Intensive Care Med (2005) 31: 1255. doi:10.1007/s00134-005-2717-y

Abstract

Objective

This study examined whether volumes can be accurately measured at the expiratory valve of a conventional ventilator using pressure support ventilation and positive end expiratory pressure with software compensation for circuit compliance available in the Servo ί ventilator.

Design and setting

Comparison of two methods for measuring tidal volume in an animal laboratory.

Subjects

Twenty healthy, intubated, sedated, spontaneously breathing pigs.

Interventions

Volume was measured in ten neonatal-sized and ten pediatric-sized pigs ventilated with the Servo ί ventilator using pressure support ventilation and positive end expiratory pressure with and without circuit compliance compensation. We compared volume measured at the airway opening by pneumotachography to volume measured at the expiratory valve of a conventional ventilator.

Measurements and results

The use of circuit compliance compensation significantly improved the agreement between the two volume methods in neonatal-sized piglets (concordance correlation coefficient: with circuit compliance compensation, 0.97; without, 0.87, p=0.002). In pediatric-sized pigs there was improvement in agreement between the two measurement methods due to circuit compliance compensation (concordance correlation coefficient with circuit compliance compensation, 0.97; without, 0.88, p=0.027). With circuit compliance compensation off there was positive bias: mean difference (bias) 2.97±0.12 in neonatal-sized and 3.75±0.38 in pediatric-sized pigs.

Conclusions

Our results show that volume can be accurately measured at the expiratory valve of a conventional ventilator in neonatal- and pediatric-sized animals.

Keywords

Respiratory physiology Mechanical ventilation Lung volume measurements Reproducibility of results 

Copyright information

© Springer-Verlag 2005

Authors and Affiliations

  • Mark J. Heulitt
    • 1
    • 2
  • Shirley J. Holt
    • 2
  • Tracy L. Thurman
    • 2
  • Renée A. Hall
    • 3
  • Chan-Hee Jo
    • 3
  • Pippa Simpson
    • 3
  1. 1.Arkansas Children’s HospitalLittle RockUSA
  2. 2.Section of Critical Care Medicine, Department of Pediatrics, College of MedicineUniversity of Arkansas for Medical SciencesLittle RockUSA
  3. 3.Section of Biostatistics, Department of Pediatrics, College of MedicineUniversity of Arkansas for Medical SciencesLittle RockUSA