LEARNING OBJECTIVES

1. 1 list and describe the components of inspired and expired air

2. 2 list and describe the important lung volumes

3. 3 describe a spirometer

4. 4 describe impedance plethysmography

5. 5 describe apnea

6. 6 describe capnography

7. 7 list and describe the functions and settings of a ventilator

8. 8 describe and characterize high-frequency ventilation

9. 9 describe the method of connection between patients and the ventilator

10. 10 describe nebulizer, oxygen tent, and humidifier

Introduction

The focus of this chapter is external human respiration. Moving air in and out of the lungs is external respiration and the focus of technological interventions. The exchange of gases in the alveoli is part of internal respiration, but it is not essential to this chapter. Here are some important facts related to respiration:

1. Make-up of air: 79% nitrogen, 20.96% oxygen, and 0.04% carbon dioxide

2. Make-up of expired air: 79% nitrogen (unaffected by respiration), 17% oxygen, and 4% carbon dioxide (human's waste product)

It is important to know that the exchange of gas in the lungs occurs in the alveoli.

Respiration measurements

Volumes of gases that fill the lungs during different moments in respiration are important to BMETs since many machines try to fill those volumes. Amounts vary by the age, height, gender, and physical condition of a patient.

Tidal volume: Breathing volume is about 500 milliliters (mL) for an average adult male. This is the main value of importance. Figure 8.1 shows a sine wave that illustrates the action of breathing in and out.