Relations: Above, it is connected by the cricothyroid membrane to the larynx. Below, the trachea continues with the first tracheal cartilage. Behind is the gullet and in front is skin. Muscles associated with swallowing and phonation are attached, and the lobes of the thyroid gland rise to its sides.
The narrowest point in the child's airway is within the cricoid cartilage. See croup. Endotracheal tubes seal in the child by fitting (loosely) within that ring, whereas in the adult a more distal balloon is necessary and used.
The cricoid is the complete ring of cartilage about the trachea, this permits the important anaesthetic manoeuvre named after Brian Sellick in which corretly applied pressure on the cricoid closes off the oesophagus and (usually) prevents regurgitation at emergency induction of anaesthesia which otherwise might kill the patient.
Cricoid pressure, Sellick's manouvre, is not universally regarded as essential, being less common in some countries than in the UK. In the UK it is regarded as a mandatory part of rapid sequence induction of anaesthesia - it is safe to talk about whether it is as wonderful as originally thought, but not safe by at least the Bolam test to decide to abandon as an individual. The sensible argument that if it is applied it may be released if it is causing difficulty seems hard to improve upon.
The space between the cricoid and the larynx is a relatively easy and safe place to cut and put in an emergency airway if the larynx is inaccessible or impassable, or as a means of gaining access to the trachea for suction of secretions and other purposes in a patient who is not intubated via the larynx. It is easier than a tracheostomy. Crico-thyrotomy Kits are available.
This article is a stub. Please feel free to expand it and make it more encyclopaedic.
- ↑ Sellick, BA Lancet 1961
- ↑ Minerva Anestesiol. 2012 May 28. [Epub ahead of print] Survey on controversies in airway management among anaesthesiologists in the UK, Austria and Switzerland. Theiler L, Fischer H, Voelke N, Basciani R, Hasty F, Greif R. Department of Anaesthesiology, Perioperative Medicine and Pain Management, University of Miami MillerSchool of Medicine, Miami, Florida, United States - email@example.com. http://www.ncbi.nlm.nih.gov/pubmed/22643540