Human Respiratory System Overview

Study Notes

Two lungs: five lobes
- Left: upper and lower
- Right: upper, middle, and lower
Pleura
Mediastinum
Bronchi and bronchioles
Alveoli

Inspiration: Diaphragm contracts (movement of chamber floor downward), external intercostal muscles contract, decreasing intrathoracic pressure (negative pressure), air enters airways, filling and expanding the lungs
Expiration: Diaphragm relaxes (movement of chamber floor upward), external intercostal muscles relax, increasing intrathoracic pressure (positive pressure), air exits airways, deflation and elastic recoil of the lungs
1 Respiration = inspiration (1/3 of the cycle) and expiration (2/3 of the cycle)

Normal breath sounds:
- Vesicular
- Bronchovesicular
- Bronchial
Abnormal (adventitious) breath sounds:
- Crackles
- Stridor
- Wheezes
- Friction rub
- Refer to Table 20-7

Administration of oxygen at greater than 21% to ensure adequate blood oxygen transport.
Aims to reduce breathing effort and myocardial stress.
Hypoxemia refers to decreased arterial oxygen tension in the blood.
Hypoxia signifies reduced oxygen supply to tissues and cells, potentially caused by non-respiratory issues.
Severe hypoxia can be life-threatening.

Can arise from prolonged exposure to high oxygen concentrations (over 50%).
Symptoms include chest discomfort, tingling sensations, shortness of breath, restlessness, fatigue, malaise, worsening respiratory difficulties, unresponsive hypoxemia, lung collapse, and lung infiltrates on X-ray.
Prevention: Utilize the lowest effective oxygen concentrations and employ positive end-expiratory pressure (PEEP) or continuous positive airway pressure (CPAP) to minimize or reverse lung collapse and reduce oxygen requirements.

Oxygen can be delivered via cylinders, piped-in systems, or concentrators.
Classified as low-flow or high-flow methods.
Devices include nasal cannula, oropharyngeal catheter, masks, and transtracheal catheter.

Two types: volume-based or flow-based.
Encourages slow, deep inhalations to maximize lung inflation and alveoli expansion.
Used to prevent or treat lung collapse.
Indications include post-surgery recovery.
Nursing care includes patient positioning, encouraging use, setting realistic goals, recording outcomes, and providing patient education.

Handheld device that delivers moisturizing agents or medications into the lungs.
Indication: Difficulty clearing secretions, reduced lung capacity, and inefficacy of simpler methods.
Nursing care includes instructing patients to take slow, deep breaths through the mouth, hold for a few seconds, encourage coughing, and monitor therapeutic effectiveness.

Includes postural drainage, chest percussion and vibration, and breathing retraining.
Goals: Remove secretions, improve ventilation, and enhance respiratory muscle efficiency.

Positions the patient to leverage gravity to help remove bronchial secretions since secretions tend to pool in the lower lungs due to upright posture.
Facilitates drainage from affected bronchioles to the trachea and bronchi, enabling removal through coughing or suctioning.
Utilized to prevent or alleviate bronchial obstruction caused by secretion buildup.

Chest percussion involves rhythmically striking the chest wall with cupped hands over the lung segment needing drainage.
Vibration involves applying manual compression and tremor to the chest wall during exhalation.
An inflatable high-frequency chest wall oscillation (HFCWO) vest can also be used for chest therapy.