215 Respiratory Emergencies

Question 1

List the individual components of the respiratory system

Answer 1

Controller
- Brain stem
- Cortical-volitional
- Cortical-behavior
Ventilatory pump
- Ventilatory muscles
- Bones; joints of the thorax
- Airways
- Peripheral nerves
- Pleura
Gas exchanger
Alveoli
Pulmonary circulation

Uptodate: Approach to the patient with dyspnea

Question 2

List and explain the non-respiraotry functions of the lungs

Answer 2

Nonrespiratory functions of the lung include its own defense against inspired particulate matter, the storage and filtration of blood for the systemic circulation, the handling of vasoactive substances in the blood, and the formation and release of substances used in the alveoli or circulation.

https://accessmedicine.mhmedical.com/content.aspx?bookid=575&sectionid=4

Question 3

Identify the muscles of respiration

Answer 3

Primary: diaphragm and external intercostal muscles
Accessory Inspiration: pectorals, sternocleidomastoid, and scalenes
Accessory Exhalation: abdominal (and intercostals again)

POLLACK ch6 Respiratory

Question 4

Explain the role of the lungs in the management of acid-base balance

Answer 4

Acid-base balance is maintained by normal pulmonary excretion of carbon dioxide (and metabolic utilization of organic acids and renal excretion of nonvolatile acids)

Bicarbonate-carbon dioxide buffer system:
** Dissolved CO2 + H2O ↔ H2CO3 ↔ HCO3- + H+**

Respiratory compensation begins rapidly vs. renal compensation (3-5days for completion)

Uptodate: Simple and mixed acid-base disorders

Question 5

List and explain the five factors associated with normal functioning lungs

Answer 5

1. Ventilation- adequate bulk flow of gas in/out of lungs
2. Distribution- gas must be delivered to areas of the lung able to exchange gas (changes in compliance/resistance will affect)
3. Diffusion - AC membrane
4. Perfusion- pulmonary vasculature flow and contact with alveolus
5. Circulation- heart pumping out to systemic circulation and adequate Hgb levels

POLLACK Ch. 6 Respiratory- Physiology of the Resp system

Question 6

List the mechanisms of hypoxemia

Answer 6

Type I respiratory failure, PaO2<60mmHg
1. Decreased inspired O2 pressure (high altitude)
2. Hypoventilation (High PaCO2 and normal A-a)
3. Impaired Diffusion (AC membrane, interstitium)
4. V/Q Mismatch
5. Shunt

Question 7

List the mechnisms of hypercapnea

Answer 7

Won’t breathe- CNS
Can’t breathe
- PNS
- Respiratory muscles
- Chest wall and pleura
- upper airway

Uptodate: Mechanisms, causes, and effects of hypercapnia

Question 8

Distinguish between oxygenation and ventilation

Answer 8

Oxygenation- process of oxygen diffusing passively from the alveolus to the pulmonary capillary, where it mostly binds to hemoglobin in red blood cells (oxyhemoglobin); a small proportion directly dissolves into the plasma.

Ventilation- bulk flow of gas in/out of lungs to supply oxygen, remove carbon dioxide, and help maintain acid-base homeostasis.

Question 9

define inspiratory reserve volume (IRV)

Answer 9

Amount of air that can be inhaled on top of a tidal volume

Question 10

Define tidal volume (Vt)

Answer 10

Volume of air moved in/out of lungs with each respiratory cycle (quiet breathing)

Question 11

Define Expiratory Reserve Volume (ERV)

Answer 11

the air that can be expelled from the lungs after a nomal exhalation

Question 12

define residual volume

Answer 12

the amount of air remaining in the lungs after the expiratory reserve volume is exhaled

Question 13

define functional residual capacity (FRC)

Answer 13

the amount of air remaining in the lungs after normal expiration; the sum of FRC= residual + expiratory reserve volume

Question 14

define vital capacity (Vc)

Answer 14

the maximal amount of air that can be exhaled following a maximal inspiration; Vc= Vt + IRV + ERV (approx. 80% of total lung capacity)

Question 15

define total lung capacity (TLC)

Answer 15

the maximal amount of air that can fill the lungs;
TLC= Vt + IRV + ERV + residual volume