Oxygenation

Oxygenation

• Overview of gas exchange and its significance.

Anatomy of the Airway

• Upper Airway:
    - Pharynx
    - Trachea
    - Epiglottis

• Lower Airway:
    - Trachea
    - Bronchi
    - Bronchioles

Airway Anatomy & Physiology

• Carina:
    - Definition: Cartilage located at the point where the trachea divides into the two bronchi.

Clinical Oxygenation Form

• Importance of using a stethoscope during the assessment of oxygenation.

• Listening to both the front and the back of the chest for optimal evaluation.

Control of Breathing

• Chemoreceptors:
    - Function: Monitor O2 and CO2 levels in the blood.
    - Mechanism: Send electrical signals to the brain for the control of breathing.
    - Neural Pathways: Signals travel via the glossopharyngeal (9th) and vagus (10th) cranial nerves.
    - Effects on Autonomic Functions: Influence the sympathetic nervous system, impacting blood pressure, heart rate, and acid/base balance.

Blood Flow in the Respiratory System

• Pulmonary Artery:
    - Carries oxygen-poor blood from the heart to the lungs.
    - Originates from the right ventricle and splits into right and left pulmonary arteries, supplying each lung.

• Pulmonary Veins:
    - Carry oxygenated blood from the lungs to the left atrium of the heart.
    - Comprise the pulmonary circuit, characterized by switching blood between the lungs and heart.
    - Contain more oxygen compared to pulmonary arteries.

Cardiac and Respiratory Blood Flow Sequence

1. Blood flows from the vena cava to the right atrium.

2. Through the tricuspid valve to the right ventricle.

3. Through the pulmonary valve to the pulmonary artery.

4. To the lungs.

5. Through the pulmonary veins.

6. To the left atrium.

7. Through the mitral valve to the left ventricle.

8. Through the aorta and back out to the body.

Functions of the Pulmonary System

• Inhalation/Exhalation:
    1. Diaphragm: Contracts during inhalation, pulling lung bases down.
    2. Intercostal Muscles: Pull ribs outward for chest expansion.
    3. Pleural Membrane: Pulls the chest cavity outward.
    4. Lung Expansion: Creates negative pressure during inhalation.
    5. Exhalation: Chest relaxes and returns to resting size.
    6. Accessory Muscles: Engaged during difficult breathing, not typically used for normal respiration.

Accessory Muscles

• Muscles Utilized for Breathing:
    - Trapezius
    - Scalenus
    - Sternomastoid

Ventilation Levels

• Hyperventilation: Rapid breathing, more than 20 breaths per minute.

• Eupnea: Normal breathing rate, between 12-20 breaths per minute.

• Hypoventilation: Shallow breathing, less than 12 breaths per minute.

External Factors Affecting Breathing

• Developmental Stages:
    - Premature Infants (born before 35 weeks gestation):
      1. Lack of a fully developed alveolar surfactant system.
      2. Immature pulmonary circulation.
    - Mature Infants (36-42 weeks gestation):
      1. Narrowing of airways.
      2. Immature CNS & immune system.
      3. Increased choking risk on small objects.
    - Toddlers:
      1. Enlarged tonsils and adenoids.
      2. High exposure to infections (daycare influence).
    - School-aged Children:
      1. Suffering from upper respiratory infections (both viral and bacterial).
      2. Asthma prevalence.
      3. Impact of tobacco exposure (2nd and 3rd hand smoke).  

•  - Adolescents:
      1. Exposure to smoking, chewing tobacco, vaping, and e-cigarettes.
    - Young to Middle Adults:
      1. Continued tobacco exposure and vaping influence.
      2. Gastroesophageal reflux disease (GERD) can lead to airway swelling due to stomach acid entering lungs.
    - Older Adults:
      1. Chronic smoking impacts lung function.
      2. Reduced physical activity.
      3. Decreased lung expansion ability.
      4. Weakened immune response.
      5. GERD prevalence increases.     

• 6. Strictures of aging defined:
        - 65-74 years: Young old.
        - 75-84 years: Middle old.
        - 85 years and up: Old old.

Environmental Factors

• Stress and Allergic Responses:
    - Body reacts with histamine production (use of antihistamines).

• Altitude Impact:
    - Higher altitudes reduce oxygen availability due to decreased atmospheric pressure.

• Temperature and Humidity Effects:
    - Body struggles to maintain correct temperature and oxygen levels.

• Physical Activity:
    - Increased movement or exercise affects oxygen demands.

Lifestyle Factors

• Pregnancy: Increased oxygen demand.

• Occupational Hazards: Exposure risks from chemicals, dust, mold, and asbestos.

• Nutrition: Importance of a balanced intake (proteins, carbohydrates, and fats).

• Obesity Implications: Can lead to obstructive sleep apnea or decrease lung expansion.

• Exercise: Increases oxygen demand.

• Substance Abuse: Impact from medications and illegal drugs can alter oxygen requirements.

Patient Assessment Techniques

• Role of the Healthcare Provider:
    - Function as a detective in gathering patient information.
    - Importance that patients may not provide a complete account of health status.

• Information Gathering Strategies:
    - Conduct assessments, ask pertinent questions, review charts, and consider both personal and family health histories.

Pathological Alterations Related to Gas Exchange

• Hypoxemia:
    - Definition: Low oxygen levels in the blood indicating potential breathing or circulation issues.
    - Signs/Symptoms: Shortness of breath, rapid breathing, fast or pounding heartbeat.

• Hypoxia:
    - Definition: Inadequate oxygen supply to the body or to specific tissues.
    - Signs/Symptoms: Wheezing, restlessness, dyspnea.

• Hypercarbia:
    - Definition: Elevated carbon dioxide levels in the blood.
    - Signs/Symptoms: Flushed skin, drowsiness, inability to concentrate.

• Hypocarbia:
    - Definition: Decreased CO2 levels below the normal reference range of 35 mmHg.
    - Signs/Symptoms: Lightheadedness, dizziness, faintness.

Importance of Patient Assessment

• Serves to collect vital information about the patient.

• Essential for communicating relevant information to other healthcare professionals.

• Areas for assessment include pain levels, respiratory patterns, cough characteristics, sputum production, lifestyle factors, and allergies.

Testing Factors and Techniques

• Skin Testing (e.g., TB testing):
    - Used to detect exposure to tuberculosis.

• Allergy Testing:
    - Identifies antigens that trigger histamine reactions.

• Pulse Oximetry:
    - Measures blood oxygen saturation levels.

• Capnography:
    - Measures inhaled and exhaled carbon dioxide levels.

• Spirometry:
    - Assesses lung function through air movement analysis.

Pulse Oximeter Use

• Common locations for use:
    - Finger.
    - Earlobe.
    - Toes.

• Note: If nail polish is present, reposition pulse oximeter for reading or use alternative site like the earlobe.

• This task can be delegated to unlicensed assistive personnel (UAP) or licensed practical nurses (LPN).

Mechanism of the Pulse Oximeter

• Functionality:
    - Absorbs different wavelengths of light (red and infrared) based on the presence of oxygenated hemoglobin.
    - Light passage helps determine hemoglobin saturation, resulting in readings of blood oxygen levels.

Cupping or Postural Drainage Techniques

• Patient positioning for effective mucus clearance:
    - Sitting up but leaning over.
    - Hips elevated.
    - Lying on side.
    - Lying on stomach.

• Percussion: Conducted over affected lung regions to assist in mucus loosening.

• Encourage patient to cough to enhance expectoration of mucus.

Oxygen Delivery Systems

• Various devices include:
    - Nasal Cannula. 1-10 mL
    - Face Masks (including partial rebreather, non-rebreather).
    - Venturi Mask.
    - Face Tent.
    - Tracheostomy Collar.

Nasal Cannula Usage Protocol

• Ensure cannula is connected to an oxygen source.

• Always utilize a humidifier bottle for comfort (moist air).

• Ensure prongs are oriented downwards during application.

Overview of Bronchodilators

• Purpose: Medications inhaled into the lungs for respiratory disease management.

• Function:
    - Relax smooth muscles lining the airways.

• Inhaled Corticosteroids:
    - Impacts on reducing swelling and tightness in airways.

• Hypertonic Saline:
    - Higher saline concentration than isotonic solutions; pulls fluid from interstitial to intravascular space, helping to mobilize mucus and improve airway clearance.

• Pulmozyme:
    - Specifically used for managing cystic fibrosis by thinning mucus.

Tracheostomy Care & Suctioning Techniques

• Detailed practices and protocols for caring for and suctioning a tracheostomy as presented in related pages.