Paediatric “tube” sizes

You decided to intubate a child and wisely remembered that you should also follow with an NG/ OG after intubation to decompress the stomach.  In order to avoid the blank stare when asked “what size”?  Here’s a nice mnemonic about Pediatric “tube” sizes… easy as 1-2-3-4!!!  Please note ETT = endotracheal tube size.

  • 1 x ETT = (age/4) + 4 (formula for uncuffed tubes)
  • 2 x ETT = NG/ OG/ foley size
  • 3 x ETT = depth of ETT insertion
  • 4 x ETT = chest tube size (max, e.g. hemothorax)

So for example, a 4-year-old child would get intubated with a 5-0 ETT inserted to depth of 15 cm (3x ETT), a 10Fr NG/OG/foley (2x ETT), and a 20Fr chest tube (4x ETT).

Also, remember that you can use cuffed tubes in any child except neonates but the formula needs to be adjusted as follows: cuffed endotracheal tube ID (mm) = (age/4) + 3.5

Where do you stick that chest tube?

Triangle of Safety

Chest Tube Insertion

The triangle of safety is bordered by the anterior axillary line (pectoralis major) and posterior axillary line (latissimus dorsi) and the 5th intercostal space (roughly the level of the nipple in a thin male). The only muscles you need to go through are the serratus anterior and intercostals. The only structure of significance is the long thoracic nerve. If injured it will produce a winged scapula. This is rare. This the first choice for chest tube insertion in trauma.