206-Respiratory Care and Oxygenation

Two divisions of the respiratory system

Upper airway: nose, mouth, larynx

Lower airway: trachea, bronchi, bronchioles, alveoli

Ventilation

Movement of air in and out of the lungs

Perfusion

Ability of the cardiovascular system to pump oxygenated blood to the tissues and return deoxygenated blood to the lungs

Diffusion

Movement of gases across membranes from high to low concentration

Internal (cellular) respiration

Exchange of O₂ and CO₂ between blood and body tissues

Movement of O₂ & CO₂ in internal respiration

O₂: moves from blood → tissues

CO₂: moves from tissues → blood

Percentage of oxygen carried by hemoglobin

Transports about 97% of oxygen → tissues

Deficiency causes anemia

Primary stimulus for breathing

Increased CO₂ levels in the blood

The main trigger keeping us breathing

Anemia’s affect on oxygenation

Decreases hemoglobin → reduces oxygen-carrying capacity → fatigue

What happens when chest wall movement decreases?

Ventilation decreases

Respiratory diseases affecting oxygenation

Asthma, emphysema (type of COPD), sleep apnea

Affects altered blood volume, cardiac output, vascular resistance

Barrel chest

Enlarged chest from air trapping and overuse of accessory muscles

Seen in COPD/emphysema patients

AP Transverse ratio 1:1

Lifestyle/Environmental factors affecting oxygenation

• Smoking

• Pollution,

• Obesity

• Stress

• Inactivity

• High altitude (carries a risk for pulmonary or cerebral edema)

Best position to improve oxygenation

High Fowler’s position

Allows the diaphragm to descend, making it easier for the lungs to expand

Device monitoring oxygen saturation

Pulse oximeter- monitors trends in patient

Normal range: 95-100%

Independent Nursing Interventions to promote oxygenation

Positioning: High Fowlers

Assess/Monitor: Listening to patient, pulse ox

Teaching: Smoking cessation, oxygen safety, and proper breathing techniques.

Dependent Interventions to promote oxygenation

• Drawing Arterial Blood Gases (ABGs)

• Administering oxygen therapy

• Medications (inhalers/nebulizers)

• Respiratory therapy (RT)

Early signs of hypoxia

• Tachycardia

• Restlessness

• Tachypnea (rapid breathing)

• Confusion

• Hypertension (high BP)

Late signs of hypoxia

• Bradycardia

• Bradypnea (slow breathing)

• Hypotension (low BP)

• Cyanosis

• Clubbing

Incentive spirometry

Prevents atelectasis (alveolar collapse) by promoting deep breathing

Instructions: sitting upright, sealing lips around the mouthpiece, and inhaling slowly to raise the piston, aiming for the target goal 10 times every hour while awake.

Pursed-lip breathing

Inhale deeply → exhale slowly through pursed lips (like blowing through a straw)

Ex: exhaling twice as long as you inhaled

Rationale: Prevents alveolar collapse and reduces work of breathing (COPD)

Diaphragmatic/Abdominal breathing

Deep breathing using diaphragm and abdominal muscles

Rationale: Decreases air trapping and reduces the work of breathing

Normal FiO₂ on room air

FiO₂: fraction of inspired oxygen- percentage/concentration of oxygen a person inhales

Normal room air~21%

Nasal Cannula (NC) flow rate & FiO₂

Delivers 1-6 L/min (FiO2 ~24-44%)

Pros: Comfortable, allows the patient to eat and talk

Nursing Care: Prevent dryness (water-soluble gel), humidify ≥4 L/min, assess skin (ears/nares)

Simple Face Mask flow rate & FiO₂

Delivers 6-12 L/min (FiO2 35-50%)

*Flow rates must be ≥6 L/min to prevent patient from rebreathing their own exhaled CO₂.

Partial Rebreather Mask

Delivers 6-11 L/min

Nursing Care: Keep the reservoir bag 1/3 to 1/2 full on inspiration

Non-rebreather mask flow rate & FiO₂

Delivers 10-15 L/min (FiO2 80-95%)

Application: Delivers the highest O₂ concentration possible before intubation

Tip: Ensure the reservoir bag stays 2/3 full

Use: Used for critical/severe hypoxia.

Venturi Mask flow rate & FiO₂

Delivers 4-12 L/min (FiO2 24-50%)

Delivers the most precise oxygen concentration

Application: Best oxygen device for chronic lung disease (COPD) patients

Why avoid high administration oxygen in COPD patients?

Their trigger to breathe is low oxygen.

Too much oxygen eliminates hypoxic drive → hypoventilation, apnea, and respiratory failure.

Oral airways vs. Tracheostomy/Endotracheal (ET) technique

Oral airways: clean technique

Endotracheal (ET) & Tracheostomy tubes: sterile technique (prevent HAIs)

Suctioning rules

Positioning: Semi-Fowler’s

Time frame: 5-15 secs max (per pass)

Max # of passes: 3

Pressure: 80 - 120 mmHg of suction pressure

*Tip: stop if HR changes, arrhythmias, SpO₂ < 90%

Why hyperoxygenate before suctioning?

Prevent hypoxemia (below-normal level of oxygen in arterial blood)

Hyperoxygenate the patient with 100% FiO2

Urine Collection

Can be random, clean catch (sterile), or timed (24-hour collection)

Application: keep on ice or refrigerated- (24-hour collection)

Stool collection

Test for occult blood, C-diff, parasites

Send to the lab immediately or refrigerate (exception: guaiac slides are typically kept at room temperature).

Tip: Use a tongue blade to place the sample in the container.

Sputum collection (AFB/Tuberculosis)

3 consecutive morning samples

Application: rinse mouth sputum collection (prevents contamination)

Why are ABGs placed on ice?

Prevent oxygen metabolism → preserves accuracy

Arterial Blood Gases: measures levels of oxygen, carbon dioxide (bicarbonate), and pH balance in arterial blood

Normal PaO₂ (Partial Pressure of Oxygen in Arterial Blood)

80–100 mmHg

PaO₂: measures pressure of oxygen dissolved in arterial blood

Sodium normal range

135–145 mEq/L

Potassium normal range

3.5–5.0 mEq/L

Chloride normal range

98–106 mEq/L

CO₂ normal range

23–30 mEq/L

BUN normal range

Blood Urea Nitrogen

10–20 mg/dL

Creatinine normal range

0.5–1.2 mg/dL

Glucose normal range

70–115 mg/dL

What does an EGD examine?

Esophagus, stomach, duodenum (small )

Rationale: Patient must remain NPO for 6 to 12 hours before the procedure

Pre-test nursing responsibilities

Consent, NPO, baseline VS, allergies

Intra-test responsibilities

Support, positioning, airway management

Post-test responsibilities

Monitor VS, airway, bleeding, I&O

What must be checked before contrast CT scan?

Kidney function (BUN/Creatinine) and allergies (Shellfish allergy)

WBC normal range

5,000–10,000/mm³

Platelets normal range

150,000–450,000/mm³

Hemoglobin normal range (male/female)

Male: 14–18 g/dL

Female: 12–16 g/dL

Hematocrit normal range (male/female)

Male: 41% – 50% (or 40.7%–50.3%)

Female: 36% – 48% (or 36.1%–44.3%)