Airway part 1

A partially or fully occluded airway will reduce/deplete airflow into and out of the lungs, reducing or halting any gaseous exchange. Following a reduction/halting of gaseous exchange, the body will quickly become hypoxic and hypercapnic as it uses up its remaining oxygen within the blood and carbon dioxide cannot be removed through respiration. Tissues will start to work in an anaerobic state due to lack of oxygen, causing further acidosis.

If there is a fully occluded airway with no oxygen supply, depending on the health and age of the patient, brain cell damage can begin from 1-2 minutes. At around 3-5 minutes brain cells begin to die, and from 10 minutes, significant brain damage has occurred and the chances of patient survival are low. Within the brain, neurons are affected first, followed by the neuroglial cells. Within the body, mass cellular death occurs throughout with increasing acidosis and hypoxia/anoxia, haemostatic balance is significantly disrupted, major organs begin to fail, and cardiac arrest follows.

If there is a partially occluded airway with some oxygen supply and carbon dioxide expulsion, then the pathphysiological processes leading to cardiac arrest will be extended depending on the airway severity.

For a clinician to manage the airway, stepwise airway management is considered an effective and logical approach. The stepwise approach follows a range of interventions from basic manoeuvres and suction, all the way through to enhanced airway practice. This approach can be used as a sliding scale, advancing up the steps to provide a patent airway where the others have failed. The clinician can also move down the steps if they feel the manoeuvre is too difficult or are unable to obtain a patent airway with the more advanced skill. For example, being unable to intubate due to a difficult anatomical structures and returning to a Supraglottic Airway (SGA) device.

Working through the flow of the stepwise airway approach;

  • Starting with the most basic is to look within the airway and remove any visible obstructions via suction or forceps. The clinician can also use a laryngoscope to observe any further objects requiring removal. If C-spine is not considered, then patient positioning can also be used to allow vomit or secretions to flow from the airway.
  • Following the removal of any obstructions, the next manoeuvres include the ‘head-tilt chin-lift’ if there are no C-spine concerns, or the ‘jaw-thrust’ if there is C-spine concerns. Both manoeuvres allow for an opening of the airway and can help maintain airway patency.
  • Next are the Oropharyngeal and Nasopharyngeal Airway (OPA NPA). A correctly sized OPA can help maintain airway patency and keep the tongue in a normal position. If there is an element where an OPA cannot be inserted, e.g., where a patient has trismus, then an NPA can allow some airway patency via the nasopharyngeal route.
  • An SGA device can be used as a further step, sitting directly above the glottic opening, and providing some protection to the airway from vomit or secretions. There are many forms of SGA devices and are considered simple in application but able to provide an effective airway
  • An Endotracheal Tube (ETT) and Endotracheal Intubation (ETI) provide a secure airway directly within the trachea. Although considered difficult to practice and maintain within the pre-hospital setting, some Ambulance Services have removed this skill from the Paramedic skill set.
  • If an airway is fully occluded with no resolve from the working through the stepwise airway approach, then a cricothyroidotomy airway can be used as a final step. This involves inserting a small airway tube directly into the trachea through the cricothyroid membrane. Different Ambulance Services have various cricothyroidotomy devices which can be pre-built to allow for ease of performing the procedure.
  • If the following stepwise airways fail, then further advanced clinical care will be required, and/or rapid transport to hospital.