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Automated measurement of the lower inflection point in a pediatric lung model.

Publication ,  Journal Article
Turner, DA; Heitz, D; Zurakowski, D; Arnold, JH
Published in: Pediatr Crit Care Med
July 2009

OBJECTIVE: To determine which flow setting most accurately detects the lower inflection point (Pflex) using an automated constant flow method and varying endotracheal tube (ETT) sizes with and without an airleak in a pediatric lung model. DESIGN: Interventional laboratory study. SETTING: Children's hospital research center. INTERVENTIONS: A pediatric lung model was created with Pflexs of the inspiratory pressure-volume (P-V) curve set at 5 and 10 cm H2O using the ASL 5000 Test Lung (IngMar Medical, Pittsburgh, PA). Three ETT sizes (3.0, 4.0, 5.0 mm) were tested with and without a 25% airleak. P-V curves were obtained using an automated constant flow method at ten different flow rates. MEASUREMENTS AND MAIN RESULTS: Without an ETT airleak, the lowest flow of 0.5 L/min led to the most accurate determination of Pflex regardless of ETT size or set Pflex (p < 0.001). When a 25% leak was introduced, accuracy of measured Pflex depended on both ETT size (p < 0.001) and flow rate (p < 0.001). Optimum flow rates for Pflex determination were 0.5, 1.0, and 1.5 L/min at Pflex of 5 cm H2O, and 2.0, 3.5, and 4.5 L/min at 10 cm H2O for 3.0, 4.0, and 5.0 mm ETTs, respectively (p < 0.001). CONCLUSIONS: Estimation of Pflex can be achieved using automated P-V curves with ETTs appropriate for pediatric use, with and without an airleak. ETT size and flow rate affect the accuracy of these measurements when an airleak is present, and use of increased flow rates to create the automated P-V curves can reduce error. These data support the idea that a low-flow technique provides the most accurate determination of Pflex in pediatric patients without a leak around their ETT, whereas increased flows are needed to compensate when an ETT airleak is present.

Duke Scholars

Published In

Pediatr Crit Care Med

DOI

ISSN

1529-7535

Publication Date

July 2009

Volume

10

Issue

4

Start / End Page

511 / 516

Location

United States

Related Subject Headings

  • Respiratory Mechanics
  • Positive-Pressure Respiration
  • Pediatrics
  • Models, Biological
  • Lung
  • Humans
  • 1114 Paediatrics and Reproductive Medicine
  • 1110 Nursing
 

Citation

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ICMJE
MLA
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Turner, D. A., Heitz, D., Zurakowski, D., & Arnold, J. H. (2009). Automated measurement of the lower inflection point in a pediatric lung model. Pediatr Crit Care Med, 10(4), 511–516. https://doi.org/10.1097/PCC.0b013e3181a0e274
Turner, David A., David Heitz, David Zurakowski, and John H. Arnold. “Automated measurement of the lower inflection point in a pediatric lung model.Pediatr Crit Care Med 10, no. 4 (July 2009): 511–16. https://doi.org/10.1097/PCC.0b013e3181a0e274.
Turner DA, Heitz D, Zurakowski D, Arnold JH. Automated measurement of the lower inflection point in a pediatric lung model. Pediatr Crit Care Med. 2009 Jul;10(4):511–6.
Turner, David A., et al. “Automated measurement of the lower inflection point in a pediatric lung model.Pediatr Crit Care Med, vol. 10, no. 4, July 2009, pp. 511–16. Pubmed, doi:10.1097/PCC.0b013e3181a0e274.
Turner DA, Heitz D, Zurakowski D, Arnold JH. Automated measurement of the lower inflection point in a pediatric lung model. Pediatr Crit Care Med. 2009 Jul;10(4):511–516.

Published In

Pediatr Crit Care Med

DOI

ISSN

1529-7535

Publication Date

July 2009

Volume

10

Issue

4

Start / End Page

511 / 516

Location

United States

Related Subject Headings

  • Respiratory Mechanics
  • Positive-Pressure Respiration
  • Pediatrics
  • Models, Biological
  • Lung
  • Humans
  • 1114 Paediatrics and Reproductive Medicine
  • 1110 Nursing