Author: Taravati Hossein
IARS
The bevel of tracheal tubes operates as an airflow duct. If the bevel rotates a few degrees to the right or left, most of the tidal volume will go to the same side in VCV modes. This can lead to a significant paradox, with hyperinflation of one lung and hypoinflation of the other. We use 4-6 cc/kg as the default tidal volume in situations of decreased lung compliance, such as ARDS.
It is emphasized that using PCV modes in patients with ARDS may reduce complications. However, PCV modes require more sedation and analgesic drugs, which in a hypoxic patient, may exacerbate an unstable hemodynamic situation.
What is your opinion about the effects of the distal part of the tracheal tube on the diffusion of oxygen through the lungs? Consider tracheal tube bevels, even in a position facing you, where more of the tidal volume will go to the right lung due to the steeper angle and dilated right main bronchus, which produces lower resistance against airflow in VCV modes.