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  • Poster presentation
  • Open Access

In vitro comparison of the standard and the Cole endotracheal tubes with an endotracheal tube of new design

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  • 1,
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  • 2,
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Critical Care200610 (Suppl 1) :P50

  • Published:


  • Computer Simulation
  • Emergency Medicine
  • Internal Diameter
  • Endotracheal Tube
  • Spontaneous Breathing


To assess in vitro the usefulness of three paediatric uncuffed endotracheal tubes of various shapes: a standard (one-diameter) tube, a Cole tube and the newly designed cone tube, use of which is not associated with an increased risk of periglottic trauma.


The flow (0–30 lpm) resistance (RETT) was measured across the length of each tube and repeated for similar tubes of internal diameters 3, 3.5 and 4 mm. The imposed work of breathing (WOBI), necessary to overcome the tube resistance, the patient's resistive work of breathing (RWOB) and the pressure-time product (PTP) were determined from the computer simulation of a spontaneous breathing, intubated infant.


The resistance of the 3.5 mm ID cone tube to 10 lpm air flow was 44% and 6% lower when compared with the resistance offered by the standard and the Cole tubes, respectively. The WOBI necessary to overcome the cone tube resistance was approximately 44% and 6% lower than with using the standard and the Cole tubes, respectively. The RWOB and PTP of the virtual infant intubated with the cone and with the Cole tubes were similar; however, the values of both parameters decreased by 18% and 8%, respectively, in comparison with the situation when a standard tube was used.


Replacement of a standard endotracheal tube with the cone or Cole tubes resulted in a significant decrease of RETT, WOBI, RWOB and PTP.



The study has been supported by the Foundation for Polish Science.

Authors’ Affiliations

Centre of Excellence ARTOG, Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Warsaw, Poland
Department of Anaesthesiology and Intensive Care, Warsaw Medical University, Warsaw, Poland


© BioMed Central Ltd 2006