1.0 Chapter Overview
In order to understand mechanical ventilation, you must first have a basic understanding of how the human body is designed to breathe. Oxygen is the food of the human body. Every cell requires it to create energy and carry out its various functions. On the other hand, carbon dioxide (CO2) is the garbage of the human body that every cell creates as a byproduct of its functions. It is commonly known that the lungs are the organ that take the oxygen from the air and bring it into the body, and that they expel (exhale) CO2 at the same time. But what is the mechanism that triggers this to happen and how exactly does this exchange occur?
The effectiveness of Mechanical Ventilation in helping with treating various lung condition depends on how it is applied. Therefore, it is essential for respiratory therapists to have a comprehensive understanding of respiratory physiology to ensure appropriate application and prompt response to any complications that may arise. This chapter aims to provide the reader with a review of respiratory physiology concepts required for understanding principles of mechanical ventilation, including intrathoracic pressure changes associated with spontaneous breathing, negative pressure breathing, and positive pressure breathing. By gaining a good understanding of these principles, respiratory therapists can optimize the use of Mechanical Ventilation and improve patient outcomes.
Application
How and when will you apply the concepts you are learning in this chapter? The mechanism of breathing is fundamental to the real-world use of ventilators. The health care professional will benefit greatly from understanding the natural process that the mechanical ventilator is intending to replicate (or imitate as closely as possible) to better aid them in using a ventilator effectively in practice.
Learning Objectives
At the end of this chapter, you will be able to:
- Explain the body mechanics of inspiration and expiration.
- Identify key parts of the body involved in breathing.
- Understand how surface tension contributes to lung recoil
- Define FRC and Intrinsic PEEP and the importance to the alveoli.
- Describe the basic pressure changes that occur in the lungs during the respiration process.
- Describe the timing and components of the respiratory cycle
- Describe minute ventilation, alveolar ventilation and dead space.
- Describe compliance, resistance and time contact and their impact on breathing
Key Terms
In this chapter, you will learn about all of the following key terms. These terms will be used throughout this book, so it is important to take the time to master them and practice your recall often.
- respiratory system
- lungs
- lobes
- alveoli, alveolus
- oxygen (O2)
- carbon dioxide (CO2)
- inspiration
- expiration
- chemoreceptors
- diaphragm
- negative pressure
- positive pressure
- Functional Residual Capacity (FRC)
- Positive End-Expiratory Pressure (PEEP)
- surfactant
- cm H2O
- Palveoli
- Ppleural
- Pao
- Pleural space
- Compliance
- Resistance
- Time constant
Whenever these terms are first introduced in this chapter, they are bolded. However, if you need additional information about a term than what is provided here, you can research it in The Free Dictionary: Medical Dictionary.
“Chapter 1 | How the Human Body Breathes” from Basic Principles of Mechanical Ventilation by Melody Bishop, © Sault College is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License, except where otherwise noted.
