Kids tubes and numbers

Trauma Pearl #6
Kids, tubes and numbers.
Today's trauma pearl is more of a tip than an article. In the heat of a trauma resuscitation, many clinicians struggle to remember sizes of tubes (ETT, gastric, urinary catheter etc.) this quick pearl is a simple and easy formula to remember.

Start with ETT (endotracheal tube)
Using the child's age
(Age/4)+4= ETT
Eg
A 6 year old boy will require a size 5.5 tube.

Once we have a tracheal time size, other sized tubes can be calculated using a simple 2x3x4x rule. Lets use the example of an 8 year old child, who is hit by a car crossing the street.  She needs a size 6 ETT.

Now apply the 2x3x4x rule.
2x
Y-suction Catheter=2 x 6 =12
IDC (urine catheter)=2x6=12
Gastric (NG) tube = 2x 6 = 12
3x
How far to insert the ETT measured at the teeth is 3x ETT size
3x 6= 18. The tube should measure 18cm at the teeth.
4x
If the child needs a chest drain the standard size is 4x ETT
8 year old needs size 6 ETT
4x6 = 24g Intercostal catheter.

This simple tool is effective for adults too. When seconds count, and the team needs to function like a well oiled machine, tips and tricks like this are gold. Can you think of any? Why not contribute them here for us all to benefit from.