The what and why of mechanical ventilation

A mechanical ventilator is a crucial piece of equipment, not least because it breathes for the people who can't. In this video from our Mechanical Ventilation Essentials course, you'll learn about what mechanical ventilation does and the indications for mechanical ventilation, as well as the general importance of optimizing ventilator settings.

In this course, we'll teach you everything you need to know about mechanical ventilation during your first night in the ICU, how to make initial adjustments in a newly intubated patient, how to fine-tune the ventilator settings to manage patients with restrictive or obstructive respiratory disease, and how to get your patient ready for extubation. We'll take you from respiratory rookie to rockstar!

[00:00:00] So, what is a mechanical ventilator and why would we need to place a patient on it? A mechanical ventilator is a life support machine that breathes for the patient. It can assume all of the work of breathing or some of the work of the breathing. In other words, it can provide full or partial respiratory support. It is usually indicated for those patients who cannot breathe adequately. In fact, mechanical ventilation is indicated when a person cannot achieve an appropriate level of

[00:00:30] ventilation to maintain adequate gas exchange and acid-base balance, which is usually obtained from an arterial puncture. It is usually manifested in an arterial blood gas in one of two ways or both. First, the patient may not adequately exhale and remove CO2 effectively. Now, the removal or exhalation of CO2 out of the body is called ventilation. A patient who is not ventilating properly

[00:01:00] exhibits increased levels of CO2 since they're not ventilating it out of the body. This patient is at risk of respiratory or ventilatory failure and is in need of mechanical ventilation or perhaps the patient might be ventilating adequately but the oxygen that's breathed into the lungs may not effectively distribute to the body. You see, the adding of oxygen into the blood is called oxygenation. A patient

[00:01:30] who is not oxygenating properly exhibits decreased levels of PaO2 on the ABG. In this case, the lungs may need the support of a mechanical ventilator but not because of poor ventilation but because of poor oxygenation. So, a mechanical ventilator can help the patient ventilate, get rid of excess CO2 and / or oxygenate, get adequate oxygen. Now, unfortunately, breathing for

[00:02:00] a patient is more complicated than simply breathing for the patient. For example, in terms of duration, how long should an inhalation last, 0.5 seconds, 1 second, 2 seconds? Or how much volume should the patient receive, 100 mL, 1000 mL? And how often should the patient receive the volume, 10 times per minute, 20 times per minute? And by the way,

[00:02:30] what oxygen concentration should you give the patient? Should you give 50% to the patient? 100%? And what about the mode of ventilation or how much pressure can the lung be inflated to? You see, answering all of these important questions and more are vital to successfully providing adequate mechanical ventilation. So, we need to first understand the basic settings and that's precisely what we will do together in this chapter.