Resistance of tracheal tubes 3.0 and 3.5 mm internal diameter

Abstract

SummaryThe resistance of RAE, Riisch, Mallinckrodt paediatric and Portex plain nasal and oral tracheal tubes with internal diameters 3.0 mm and 3.5 mm was calculated at air flows of 1 to 10 litres per minute. Theflow resistance profiles of RAE and Rusch tracheal tubes was generally higher than those of Mallinckrodt paediatric and Portex plain tubes. All RAE and Riisch nasotracheal tubes of size 3.0 mm internal diameter and orotracheal tubes 3.0 mm internal diameter had aflow resistance exceeding 3.0 kPa litreslsecond at an air flow of4 litreslminute. It is concluded that these tracheal tubes ought only to be used with assisted or controlled ventilation.

Time to stop using uncuffed tracheal tubes in children?

“…It became common to ‘down‐size’ the tube by approximately half a size. This reduction in internal diameter may decrease the likelihood of mucosal damage but results in a relatively large increase in resistance (due to the Hagen–Poiseuille equation), and a subsequent increased work of breathing during spontaneous breathing . However, there are few occasions when a child should be allowed to breathe spontaneously through a tracheal tube for any length of time; most commonly, this would occur at the end of a procedure shortly before tracheal extubation and so the increased resistance is not of real clinical concern.…”

Between evidence and commerce – the case of sufentanil sublingual tablet systems

“…It became common to 'down-size' the tube by approximately half a size. This reduction in internal diameter may decrease the likelihood of mucosal damage but results in a relatively large increase in resistance (due to the Hagen-Poiseuille equation), and a subsequent increased work of breathing during spontaneous breathing [12]. However, there are few occasions when a child should be allowed to breathe spontaneously through a tracheal tube for any length of time; most commonly, this would occur at the end of a procedure shortly before tracheal extubation and so the increased resistance is not of real clinical concern.…”

Effects of a closed system suction connector on airwayresistance in ventilated neonates

“…In in vitro studies, ETTs of different brands have been reported to have caused different airway resistance levels, and extending ETTs with connectors have also been reported to have increased tube resistance (2,3). ETT closed system suctions (CSS) have their own connectors.…”