Introduction
Endotracheal tubes created a seal between the endotracheal tube and the
trachea, preventing aspiration of fluids and pathogens from the pharynx
to the lungs and ventilation leaks. Consensus suggests that cuff
pressure in endotracheal tubes should range from 20 to 30
cmH2O[1], However, in clinical
practice cuff pressures > 30 cmH2O may be
required to create a seal in the trachea[2], The
possible reason is that cuff size may be unsuitable.
In terms of oral endotracheal tube, the global guidelines for
endotracheal tube lack clear guidance or consensus on the selection of
endotracheal tube model[3]. Foreign studies
suggest that adult female patients choose (ID) 7.0 to (ID) 8.0mm
cannula, and male patients choose (ID) 8mm and (ID) 8.5mm; In children,
traditionally, the formula based on demographic data is used to predict
the appropriate size of endotracheal tube, and the traditional formula
based on age, such as Cole [4]formula of
endotracheal tube without air bag (inner diameter [ID] [mm] =
[age at 4 years] + 4.0); For example, Motoyama formula (inner
diameter [mm] = [age in the fourth year] + 3.5) for endotracheal
tube with air bag has been widely used in children’s ETT
selection[5]. The above shows that there is no
consensus on the choice of endotracheal tube for patients, and there is
an urgent need for an accurate and feasible method.