Respiratory: Mechanical ventilation

As a nursing assistant, you will help provide safe care to clients with mechanical ventilation. This is when a machine reduces or even takes over the work of breathing from clients who find it difficult or impossible to do so without help.

The use of mechanical ventilation can range from short to long term and from care in a healthcare facility to home care.

Okay, now, mechanical ventilation can be “invasive” or “noninvasive.” Invasive mechanical ventilation involves the insertion of an artificial airway. An artificial airway is basically a tube that gets placed in the trachea.

One example of this is an endotracheal tube, which is a tube that gets inserted through the mouth and down past the pharynx and larynx into the trachea.

Another is a tracheostomy tube, which is inserted directly through an opening made in the skin of the neck, called a tracheotomy.

Typically, both types of tubes have an inflatable balloon that forms a seal against the tracheal wall. Tracheostomy tubes are also kept in place with a collar or ties wrapped around the client’s neck.

Now, the thing with endotracheal tubes is that because they go through the pharynx and larynx, the client won’t be able to speak, drink, or eat anything via the mouth, which can be extremely uncomfortable for the client.

If mechanical ventilation is required for a long period of time, a tracheostomy tube might be preferred over an endotracheal tube.

Endotracheal tubes can be used only temporarily, for a few weeks, but tracheostomy tubes can be used permanently, such as for clients whose larynx has been surgically removed due to cancer or those with paralyzing conditions that require them to stay on a ventilator permanently.

Now, tracheostomy tubes allow the client to take food or fluids normally through the mouth. Speaking with a tracheostomy tube in place has also been made possible through one-way speaking valves, such as the Passy-Muir valve.

This valve opens as the client breathes in and closes after they’ve breathed out, letting the exhaled air flow around the tracheostomy tube and up through the vocal cords and out of the mouth thus allowing voice sounds to be made.

There are various reasons why a client may need invasive mechanical ventilation.

Starting with nervous system disorders, these include damage to the spinal cord affecting the muscles responsible for breathing as well as injury to the breathing control centers in the brain caused by severe head trauma, stroke, or even intoxication by alcohol or medications that suppress brain activity, like opioids.

Invasive mechanical ventilation might be also needed during or after surgical procedures that require anesthesia; for clients with lung conditions, like respiratory distress syndrome; or heart conditions, like cardiogenic shock.

Okay now, for non-invasive mechanical ventilation, no artificial airway needs to be used. A face mask, nasal plugs, or a helmet is used instead to force air with positive pressure in the airways.

That’s why it is also called non-invasive positive pressure ventilation, or NIPPV for short. Now, this positive pressure keeps the airways open and prevents them from collapsing, allowing gas exchange to happen in the lungs.

So, positive pressure during inspiration helps oxygen get absorbed, while positive pressure during expiration helps carbon dioxide get blown out.

There are two types of NIPPV. Continuous positive airway pressure, or CPAP for short, keeps a steady positive airway pressure during both inspiration and expiration.

Bilevel positive airway pressure, or BiPAP, on the other hand, delivers two distinct levels of positive airway pressure: a higher one during inspiration and a lower one during expiration.

Now, NIPPV can provide a safe alternative to endotracheal intubation or tracheostomy in many cases.

It is mainly used to support ventilation for clients with obstructive sleep apnea as well as clients with neuromuscular diseases that affect the respiratory muscles.