Pharm 111 Week 1 Class Notes #2

Intubation Techniques

Glidescope Overview
- A device with a camera on the blade for visualization during intubation.
- Allows the clinician to see the screen while intubating.
- Older method still used by many physicians.

Airway Structures:
- Glottis: Opening between the vocal cords.
- Vocal Folds: Located at the entrance to the trachea.
- Epiglottis: Flap that closes to protect the airway during swallowing.
Patient Positioning:
- The patient lies looking up with their tongue out, which aids visualization during intubation.

Trachea:
- Known as the windpipe.
- Extends from the cricoid cartilage to the fifth thoracic vertebra.
- Composed of C-shaped cartilaginous rings for support.
Carina: Landmark at the bifurcation of the trachea into right and left bronchi.
Bronchi Structure:
- Right Main Stem Bronchus: More in line with the trachea, larger in diameter, leading to a higher incidence of right main stem intubation.
- Left Main Stem Bronchus: Longer and at an angle due to the heart's anatomy.
Foreign Body Aspirations:
- More common in the right bronchus due to its structure.

C-shaped cartilage rings provide rigidity and protection.
Sympathetic Stimulation:
- Increases the diameter of the airways, resulting in bronchodilation, facilitating airflow.
Conducting Airways:
- Consist of trachea, main stem bronchi, lobar bronchi, and segmental bronchi.
- Finally leading to the smooth muscle-dominated bronchioles which contain no cartilage.

The right lung consists of three lobes, while the left lung consists of two lobes.
Each lobe has its own respective segments for gas exchange via alveoli.
Terminal Bronchioles:
- Divide into respiratory bronchioles that ultimately contain alveoli for gas exchange.

Alveoli:
- Each lung contains around 50 million alveoli, providing a massive surface area for gas exchange, likened to half of a tennis court per lung.
- Composed of simple squamous epithelium.
Surfactant:
- A fluid secreted by type II alveolar cells to reduce surface tension and facilitate lung expansion.
- Nascent in premature infants leading to complications in breathing due to insufficient lung compliance.
Pores of Kohn:
- Small pores in alveolar walls that allow for gas movement and sharing between adjacent alveoli.

External Respiration:
- Exchange of gases between alveoli and bloodstream (pulmonary capillaries).
Internal Respiration:
- Exchange of gases between bloodstream and body tissues (systemic capillaries).

Diaphragm:
- Primary muscle of respiration accounting for 75% of airflow; functions through contraction to increase lung volume during inspiration.
Intercostal Muscles:
- External intercostals lift ribs, contributing to breathing (>25% of lung airflow).
Accessory Muscles:
- Activated during respiratory distress, visible during labored breathing.

Look for signs of respiratory distress such as accessory muscle movement and abnormal breathing patterns.
Conditions affecting compliance include pulmonary fibrosis and insufficient surfactant production.

Involves the movement of air in and out of the respiratory tract.
Tidal Volume (VT): Volume of air inhaled or exhaled during one breath.
Minute Ventilation: Calculated by multiplying respiratory rate by tidal volume, essential for assessing and preventing CO2 buildup.

Air flow occurs from high to low pressure.
Inhalation reduces lung pressure allowing air to flow in, while exhalation increases lung pressure pushing air out.

Normal quiet breathing (eupnea) vs. breathing during effort (forced breathing) reflecting respiratory distress.
Apnea entails a total lack of breathing.