16.1 Respiratory Assessment and Oxygen Therapy

Respiratory assessment and oxygen therapy are crucial skills for nurses in managing patients' oxygenation needs. These techniques allow for early detection of respiratory issues and guide appropriate interventions. From visual inspection to auscultation, nurses must master various assessment methods to provide comprehensive care.

Oxygen therapy is a key treatment for many respiratory conditions, ranging from mild hypoxemia to severe respiratory distress. Understanding different oxygen delivery devices and their indications helps nurses select the most appropriate method for each patient. Proper monitoring and awareness of potential complications ensure safe and effective oxygen administration.

Respiratory Assessment Techniques

Visual Inspection and Palpation

• Inspection evaluates respiratory rate, rhythm, depth, and effort
  • Observe chest wall movements, shape, and symmetry
  • Normal adult respiratory rate ranges from 12-20 breaths per minute
• Palpation assesses chest wall expansion and tactile fremitus
  • Place hands on posterior chest wall to feel symmetrical expansion
  • Tactile fremitus increased with consolidation (pneumonia)
• Proper patient positioning improves assessment accuracy
  • Position patient sitting upright at 45-degree angle
  • Ensure chest is fully exposed for thorough examination

Percussion and Auscultation

• Percussion involves tapping chest wall to evaluate underlying tissue density
  • Resonant sound indicates normal lung tissue
  • Dull sound suggests consolidation or pleural effusion
• Auscultation uses stethoscope to listen for breath sounds across lung fields
  • Compare sounds between left and right sides of chest
  • Assess anterior, lateral, and posterior chest systematically
• Document findings using standardized terminology
  • Note both normal and abnormal observations
  • Example: "Clear breath sounds bilaterally, no adventitious sounds noted"

Systematic Approach and Documentation

• Follow specific order for comprehensive assessment: inspection, palpation, percussion, auscultation
• Correlate assessment findings with patient history and other clinical data
• Document using clear, concise language to communicate findings effectively
  • Example: "Respiratory rate 18, equal chest expansion, resonant percussion notes throughout, vesicular breath sounds in all fields"

Abnormal Breath Sounds

Wheezes and Crackles

• Wheezes indicate airway narrowing or obstruction
  • High-pitched, musical sounds heard on expiration
  • Common in asthma and chronic obstructive pulmonary disease (COPD)
  • Example: Whistling sound heard when exhaling during an asthma attack
• Crackles suggest fluid in small airways or alveoli
  • Brief, discontinuous sounds heard on inspiration
  • Can be fine (late inspiratory) or coarse (early inspiratory)
  • Associated with pneumonia, pulmonary edema, and interstitial lung disease
  • Example: Sound similar to hair being rubbed between fingers, heard in patient with congestive heart failure

Rhonchi and Stridor

• Rhonchi caused by secretions or obstruction in larger airways
  • Low-pitched, snoring-like sounds
  • Often cleared with coughing
  • Frequently observed in chronic bronchitis or pneumonia
  • Example: Gurgling sound heard in patient with excessive mucus production
• Stridor indicates severe upper airway obstruction
  • High-pitched, inspiratory sound originating from larynx or trachea
  • Medical emergency requiring immediate intervention
  • Seen in epiglottitis or foreign body aspiration
  • Example: Harsh, squeaking noise heard when breathing in, as in case of child with croup

Other Abnormal Sounds and Interpretation

• Pleural friction rub associated with inflammation of pleural surfaces
  • Creaking or grating sound heard during inspiration and expiration
  • Typically indicates pleuritis or pneumonia
  • Example: Sound similar to walking on fresh snow, heard in patient with pleurisy
• Location and timing of abnormal sounds provide diagnostic clues
  • Inspiratory crackles in lower lobes suggest atelectasis
  • Expiratory wheezes throughout lung fields indicate bronchospasm
• Differentiation between normal and abnormal sounds requires practice
  • Compare to textbook recordings or simulation software
  • Correlate with other clinical findings and patient history

Oxygen Delivery Devices

Low-Flow Oxygen Systems

• Nasal cannulas deliver 1-6 L/min of oxygen
  • Provide 24-44% oxygen concentration
  • Comfortable for long-term use, allow eating and speaking
  • Example: Commonly used for patients with stable COPD requiring minimal supplemental oxygen
• Simple face masks deliver 5-10 L/min of oxygen
  • Provide 40-60% oxygen concentration
  • Cover both nose and mouth
  • Example: Used for patients with moderate hypoxemia, such as those with pneumonia

High-Flow Oxygen Systems

• Non-rebreather masks deliver 10-15 L/min of oxygen
  • Provide 60-80% oxygen concentration
  • Use reservoir bag and one-way valves to prevent room air entrainment
  • Example: Utilized for patients with severe hypoxemia, like those with acute respiratory distress syndrome (ARDS)
• Venturi masks allow precise control of oxygen concentration
  • Deliver 24-60% oxygen using Venturi effect
  • Beneficial for COPD patients at risk for CO2 retention
  • Example: Set to deliver 28% oxygen for a COPD patient to maintain saturation between 88-92%
• High-flow nasal cannulas deliver up to 60 L/min of heated, humidified oxygen
  • Provide both oxygenation and positive airway pressure
  • Improve patient comfort and reduce work of breathing
  • Example: Used in neonates with respiratory distress syndrome to avoid intubation

Oxygen Titration and Monitoring

• Adjust oxygen flow rates or FiO2 based on patient's needs
  • Target oxygen saturation levels (usually 94-98% for most patients)
  • Consider arterial blood gas results and clinical condition
• Monitor effectiveness of oxygen therapy regularly
  • Assess vital signs, work of breathing, and oxygen saturation
  • Example: Increase oxygen flow from 2 L/min to 3 L/min if saturation drops below 92%

Oxygen Therapy Indications vs Complications

Indications and Contraindications

• Oxygen therapy indicated for various conditions
  • Hypoxemia (SpO2 < 90% or PaO2 < 60 mmHg)
  • Respiratory distress (increased work of breathing)
  • Shock states (compromised tissue perfusion)
  • Trauma (risk of tissue hypoxia)
  • Perioperative management (prevent surgical site infections)
• Contraindications for oxygen therapy
  • Absolute contraindication in paraquat poisoning (accelerates lung damage)
  • Relative contraindication in some COPD patients with chronic CO2 retention
  • Example: Avoid high-flow oxygen in COPD patient with baseline SpO2 of 88% and elevated CO2 levels

Potential Complications and Safety Considerations

• Oxygen toxicity from prolonged exposure to high concentrations
  • Can cause lung injury and oxidative stress
  • Risk increases with FiO2 > 60% for extended periods
• Absorption atelectasis in patients on high FiO2
  • Occurs when oxygen replaces nitrogen in alveoli, leading to collapse
  • More common with FiO2 > 60%
• CO2 narcosis in some COPD patients
  • Results from suppression of hypoxic drive
  • Can lead to respiratory acidosis and altered mental status
• Mucosal drying and secretion thickening
  • Prevent by proper humidification of oxygen
  • Especially important with high-flow oxygen delivery
• Fire safety crucial with oxygen therapy
  • Oxygen supports combustion, increasing fire risk
  • Prohibit smoking or open flames near oxygen equipment
  • Example: Post "No Smoking - Oxygen in Use" signs in patient rooms

Monitoring and Reassessment

• Regular reassessment of oxygen therapy need
  • Prevent unnecessary prolonged use
  • Adjust therapy based on patient's clinical status
• Monitor for signs of oxygen toxicity
  • Chest pain, cough, shortness of breath
  • Changes in vital signs or mental status
• Assess effectiveness through regular vital sign checks
  • Oxygen saturation levels
  • Respiratory rate and work of breathing
• Document oxygen therapy details in patient record
  • Delivery device, flow rate or FiO2, patient response
  • Example: "Patient on 2 L/min O2 via nasal cannula, SpO2 96%, respiratory rate 16"