Untitled Quiz

The respiratory system is responsible for gas exchange between the air and bloodstream.
It filters, warms, and humidifies incoming air.
It facilitates vocalization (speech).
The upper respiratory tract includes the nose, pharynx, larynx, and epiglottis.
The nose and pharynx trap particles like dust and smoke.
Inhaled air is moisturized and warmed in the nasal cavities.
During exhalation, the nasal cavity collects and retains moisture from the air leaving the body.
The larynx allows air to pass through the trachea.
The epiglottis helps the larynx prevent food or liquid from entering the lower respiratory tract during swallowing.
The lower respiratory tract includes the trachea, bronchi, bronchioles, and alveoli.
The trachea branches into two bronchi, one for each lung.
The bronchi continue to divide into smaller airways called bronchioles.
The conducting zone (trachea to bronchus) transports air and no gas exchange occurs.
The respiratory zone (bronchioles with alveoli) is where gas exchange occurs.
Alveoli are the tiny air sacs in the lungs where gas exchange takes place.
They are moist, thin-walled pockets that allow for efficient diffusion of oxygen and carbon dioxide.
Surfactant, a slightly oily substance, prevents the alveoli walls from collapsing and sticking together.

Ventilation is the process of moving air in and out of the lungs.
Inspiration (inhalation) is the process of drawing air into the lungs.
Expiration (exhalation) is the process of expelling air from the lungs.
The diaphragm is the primary muscle of respiration.
Control of ventilation is regulated by the nervous system, with the medulla oblongata in the brainstem controlling the rate and depth of breathing.
Gas exchange occurs in the alveoli, where oxygen diffuses from the air into the bloodstream and carbon dioxide diffuses from the bloodstream into the air.

Oxygen is transported in the blood bound to hemoglobin.
Circulation refers to the movement of blood throughout the body.
This process brings oxygenated blood to the tissues and returns deoxygenated blood to the lungs.

Respiratory failure occurs when the lungs fail to oxygenate the arterial blood adequately and/or prevent carbon dioxide retention.
Type I Respiratory Failure is characterized by hypoxemia, a low partial pressure of oxygen (PO2) less than 60mmHg in the arterial blood.
Type II Respiratory Failure is characterized by hypercapnia, a high partial pressure of carbon dioxide (PCO2) over 50mmHg in the arterial blood.

Reduced PO2 in arterial blood (PaO2) causes a spectrum of symptoms based on severity.
Mild hypoxemia can impair mental performance, diminish visual acuity, and cause tachypnea (rapid breathing).
Profound hypoxemia can cause:
- CNS: Headache, seizures, somnolence (sleepiness), loss of consciousness.
- CVS: Palpitations (heart racing), chest pain.
- Respiratory: Shortness of breath.

Inadequate oxygenation at the cellular level
Can lead to:
- CNS: Hypoxic ischemic encephalopathy (brain damage due to lack of oxygen).
- Myocardium: Acute myocardial infarction (heart attack).
- Renal: Acute kidney injury.
- Vascular: Vasoconstriction (narrowing of blood vessels) in the pulmonary vasculature.

Increased PCO2 in arterial blood (PaCO2)
Causes a spectrum of symptoms based on severity.
Mild: Restlessness, tremor, slurred speech, asterixis (flapping tremor of the hands).
Severe: Headache, altered mental status (confusion), loss of consciousness, coma.
Symptoms and signs may also be present related to the condition causing the respiratory failure.

Identify patients with respiratory failure based on:
- Clinical symptoms and signs:
  - Respiratory: Shortness of breath, wheezing, chest tightness, cough.
  - CNS: Lightheadedness, dizziness, lethargy (sluggishness), headache, anxiety, confusion, delirium, seizures.
  - Constitutional: Manifestations related to underlying disorder.
- History:
  - Significant medical history: Pulmonary, central, neuromuscular, thoracic cage disorders.
  - Drug history: Sedatives.
  - Smoking.
Assess vital signs:
- GCS (Glasgow Coma Scale): To assess level of consciousness.
- Respiratory findings: Airway, breathing, circulation.
Resuscitate/Stabilize: Provide supportive care, including oxygen therapy, airway management, and mechanical ventilation.
Investigate:
- Blood: Arterial blood gas (ABG).
- Radiological: Chest X-ray (CXR), CT scan.
Treat the cause: Address the underlying condition responsible for the respiratory failure.

Signs:
- Vital Parameters:
  - Blood pressure: Hypotension (low blood pressure) or hypertension (high blood pressure).
  - Heart rate: Bradycardia (slow heart rate) & Tachyarrhythmias (fast and irregular heart rhythm).
  - Oxygen saturation: Hypoxemia (low oxygen levels in the blood).
  - Respiratory rate: Hypopnea (slow breathing) or Tachypnea (rapid breathing).
- Habitus: Posture, body position, and overall appearance.
- Thoracic Cage Deformities: Abnormalities in the chest wall.
- Pulmonary Examination: Wheezing, decreased breath sounds.
- Neuro-Axis Examination:
  - GCS: Somnolence (sleepiness).
  - Asterixis: Flapping tremor of the hands.
  - Limbs: Reflexes and muscle strength.

Arterial Blood Gas (ABG): Measures the amounts of oxygen and carbon dioxide dissolved in arterial blood.
- Invasive procedure requiring a blood sample from an artery (radial, brachial, or femoral).
Radiological:
- Thoracic: Chest radiograph (CXR), CT thorax (with or without contrast), pulmonary angiogram.
- Neuro-axis: CT or MRI of the brain and cervical or thoracic spine.
- Nerve Conduction Study (NCS) and Electromyography (EMG): To evaluate nerve and muscle function.