You should agree what blade to use in your hospital or practice and standardize your 'Plan D' equipment.

These broad blades are all wide enough to allow insertion of a 6 mm ETT through an incision in the cricothyroid membrane (CTM). The type of incision recommended depends on whether you can clearly identify the CTM through the skin.

The CTM may be:

• Palpable
• Unidentifiable

You should agree what blade to use in your hospital or practice and standardize your 'Plan D' equipment.

The CTM may be:

• Palpable

A single, horizontal stab incision through skin and CTM is recommended. A loss of resistance is felt in one pass as the knife enters the trachea.

• Unidentifiable

You should agree what blade to use in your hospital or practice and standardize your 'Plan D' equipment.

The CTM may be:

• Palpable
• Unidentifiable

If the midline and/or bony structures cannot be identified, a vertical incision through the skin only is recommended.

Blunt dissection using your fingers or an instrument such as curved Spencer Wells forceps or a tracheal dilator is recommended.

Once you identify the CTM, a horizontal incision is made as for the palpable CTM incision. The cricothyroidotomy incision can be enlarged if required by a gentle rocking motion of the blade. The blade is then turned 90 degrees to open the incision.