JOURNAL ARTICLE

Pressure loss caused by pediatric endotracheal tubes during high-frequency-oscillation-ventilation

Stefan Schumann, Michael Krappitz, Knut Möller, Roland Hentschel, Günther Braun, Josef Guttmann
Respiratory Physiology & Neurobiology 2008 July 31, 162 (2): 132-7
18571997
In a physical model of a pediatric respiratory system we measured the pressure drop across ETTs of 3 and 4mm inner diameter (ID) when we varied frequency, mean airway pressure and pressure amplitude of high-frequency-oscillation-ventilation (HFOV). Depending on ventilator settings the relative loss of mean pressure amplitude caused by the ETT ranged from 3.3% to 24.7% for ETT 4mm ID, respectively, from 23.8% to 51.8% for 3mm ID. In addition to the well-described flow dependency, ventilation frequency affected ETT resistance. Due to this frequency dependence, calculation of the pressure drop across the ETT using Rohrer's or Blasius-Itos' approach underestimated the true pressure drop significantly (p<0.001). Based on the experimental results, nomograms for graphical determination of the pressure drop across the ETT during HFOV were developed. We conclude that the pressure drop across the ETT during HFOV is dependent on ETT size, pressure amplitude and ventilation frequency. Calculation of this pressure drop with conventional methods is inaccurate. The high-frequency-resistance of the ETT might protect the lungs from excessive pressure amplitudes during HFOV.

Full Text Links

Find Full Text Links for this Article

Discussion

You are not logged in. Sign Up or Log In to join the discussion.

Related Papers

Remove bar
Read by QxMD icon Read
18571997
×

Save your favorite articles in one place with a free QxMD account.

×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"