High Flow Through a Nasal Cannula and CPAP Effect in a Simulated Infant Model

  • Volsko T
  • Fedor K
  • Amadei J
 et al. 
  • 44


    Mendeley users who have this article in their library.
  • 23


    Citations of this article.


BACKGROUND:Limited data are available to describe the CPAP effects that can be expected when using high flow with a traditional nasal cannula.

OBJECTIVE:To describe the relationship between the pressure generated at the airway opening and flow through a nasal cannula using a simulated infant model. We hypothesized that positive pressure generated by a standard cannula at flows > 2 L/min would be minimal and clinically unimportant.

METHODS:Nares were simulated with holes drilled in a plastic fixture. A nares template for CPAP prongs served as a sizing template for the holes. Small, medium, and large nares fixtures were constructed and connected to a lung simulator that simulated spontaneous breathing. Respiratory muscle pressure was simulated by setting a waveform and adjusting the amplitude to deliver a range of tidal volumes (V(T)) from 3 mL to 12 mL. Lung compliance and resistance were set at 0.5 mL/cm H(2)O and 125 cm H(2)O/L/s, respectively. Nasal cannulas were inserted in the model nares. We assured that the prong occlusion of the nares did not exceed 50%. Cannula flow was adjusted from 2-6 L/min in 1-L/min increments. Data were averaged over 20 breaths. Mean airway pressure and percent change in V(T) were recorded.

RESULTS:The greatest effect on V(T) (mean ± SD 0.16 ± 0.10 mL) and pressure change (mean ± SD 0.7 ± 0.5 cm H(2)O) occurred with the premature cannula. The least effect on pressure (mean ± SD 0.3 ± 0.22 cm H(2)O) and V(T) change (mean ± SD 0.01 ± 0.02 mL) occurred with the infant cannula.

CONCLUSIONS:Clinically important pressures were not generated by high flows with a standard nasal cannula. The differences in spontaneous V(T) across all flows were negligible.

Get free article suggestions today

Mendeley saves you time finding and organizing research

Sign up here
Already have an account ?Sign in

Find this document


  • T. A. Volsko

  • K. Fedor

  • J. Amadei

  • R. L. Chatburn

Cite this document

Choose a citation style from the tabs below

Save time finding and organizing research with Mendeley

Sign up for free