Chapter 44 – Airway Clearance Therapy (Vocabulary Flashcards)

Learning Objectives

• Compare normal airway-clearance mechanisms with factors that impair them.
• Identify pulmonary diseases associated with abnormal secretion clearance.
• State clinical indications for airway-clearance therapy (ACT).
• Describe technique & benefits of:
  • Chest physical therapy (CPT)
  • Directed coughing & expulsion techniques
  • Vibratory positive-expiratory-pressure (PEP) therapy
  • Mechanical insufflation–exsufflation (MIE)
  • High-frequency oscillation devices
  • Mobilization & exercise
• Evaluate a patient’s response to ACT & decide when to modify the plan.

Introduction

• ACT = non-invasive methods that improve gas exchange by mobilizing & removing secretions.
• Broad, routine use is costly & often ineffective; therapy should be targeted.

Physiology of Airway Clearance

• Requirements for normal clearance:
  • Patent airway
  • Functional mucociliary escalator
  • Effective cough able to move mucus from lower to upper airways.

Abnormal Clearance

• Any defect in airway patency, mucociliary function, muscle strength, secretion viscosity, or cough reflex → retention.
• Sequelae of secretion retention:
  • Full obstruction → mucus plugging → atelectasis → shunt → hypoxemia.
  • Partial obstruction → ↑ work of breathing, air trapping, lung over-distention, V/Q mismatch.
• Diseases often involved:
  • Airway compression (internal/external)
  • Cystic fibrosis (CF)
  • Bronchiectasis
  • Neuromuscular disorders (weak cough)
• Additional causes in intubated patients:
  • Endotracheal/tracheostomy tube
  • Suctioning trauma
  • Inadequate humidification
  • High FiO_2
  • Drugs (general anesthetics, opiates, narcotics)
  • Baseline lung disease

General Goals & Indications

• Acute: copious secretions, inability to mobilize, ineffective cough.
• Chronic: CF, bronchiectasis, ciliary-dyskinetic syndromes, COPD w/ retention.
• Prevention: combined with early mobilization in acutely ill; CPT + exercise in CF to maintain function.

Determining the Need

• Candidates: chronic secretion disorders, risk of retention.
• Physical clues: loose ineffective cough, labored pattern, coarse crackles, tachypnea, tachycardia, fever.
• CXR: atelectasis, infiltrates.

Airway-Clearance Methods (Five Approaches)

1. Chest physical therapy (CPT)
2. Cough & expulsion techniques (incl. MIE)
3. Positive-airway-pressure adjuncts
   • PEP
   • Vibratory PEP
   • High-frequency PAP
4. High-frequency compression/oscillation
5. Mobilization & physical activity

Chest Physical Therapy (CPT)

• Uses positioning, gravity, & mechanical energy to mobilize secretions.
• Techniques: postural drainage positions + percussion (manual or mechanical) + vibration.
• Steps:
  • Identify lobes/segments.
  • Explain procedure.
  • Inspect for incisions, lines, O₂.
• Limitations:
  • Requires caregiver.
  • Depends on proper positioning (Trendelenburg may be poorly tolerated).
  • Cannot perform simultaneous aerosol therapy.

Percussion & Vibration

• Manual: rhythmic cupped-hand clapping.
• Mechanical: electric/pneumatic devices supply energy.
• Goal: loosen tracheobronchial secretions to facilitate cough/suction.

Directed Cough

• Taught, supervised maneuver resembling effective spontaneous cough.
• Patient positioning + breathing control; deep inspiration then bear-down (glottic closure).
• Contraindicated in obtunded, paralyzed, or uncooperative patients.
• Technique adjustments for post-op, COPD, neuromuscular pts.

Forced Expiratory Technique (FET) – “Huff Cough”

• One or two forced expirations from mid- to low-lung volumes without glottic closure.
• Produces smaller pleural-pressure swings → less airway collapse.
• ↑ sputum yield, esp. with postural drainage; useful in COPD, CF, bronchiectasis.

Manual-Assisted Cough

• External pressure to thoracic cage or epigastrium coordinated with exhalation.
• Steps: deep inspiration (may use positive-pressure bag/IPPB) → rapid abdominal/thoracic compression at expiratory onset.
• Indication: neuromuscular pts lacking forceful expiratory muscles.

Active Cycle of Breathing Technique (ACBT)

1. Relaxation & breathing control.
2. 3–4 thoracic-expansion exercises.
3. Relaxation & control.
4. Repeat thoracic expansions.
5. Relaxation & control.
6. 1–2 FET (huffs).
7. Final relaxation & control.

Autogenic Drainage (AD)

• Patient in sitting posture uses diaphragmatic breaths at varying volumes to unstick, collect, & evacuate mucus (three phases).
• Suppress cough until all phases complete.

Mechanical Insufflation–Exsufflation (MIE)

• Positive pressure +30–+50\ \text{cm H}2\text{O} for 1–3 s → rapid switch to -30–-50\ \text{cm H}2\text{O} for 2–3 s.
• Session: ≈5 cycles followed by spontaneous breaths; repeat as ordered.

Positive-Airway-Pressure Adjuncts

• Purposes: mobilize secretions, treat/re-expand atelectasis; usually combined with other ACT.
• Modes:
  • Continuous PAP (CPAP)
  • Expiratory PAP (EPAP)
  • Positive expiratory pressure (PEP)

PEP & Oscillating PEP

• Fixed/variable resistor creates expiratory pressures 10–20\ \text{cm H}_2\text{O}.
• Oscillating PEP adds rapid flow interruptions → simultaneous pressure + vibration.

High-Frequency Compression / Oscillation

• External chest wall: inflatable vest cycles, generating pressure pulses → chest oscillations (HFCWO).
• Airway-internal: intrapulmonary percussive ventilation (IPV) delivers gas minibursts at 100–225 cycles·min^{-1} (1.7–5 Hz).

Exercise, Mobilization & Physical Activity

• Benefits: ↑ tidal volume, heart rate, cardiac output, physical conditioning; naturally aids airway clearance.

Selection Factors for Technique Choice

• Patient motivation, goals, literacy/cognition.
• Physical limits, fatigue, need for assistance.
• Caregiver/physician goals, therapist skill.
• Disease type & severity; technique limitations.
• Direct/indirect costs; possibility of method combination; ease of teaching & learning.

Outcome Assessment

• Monitor changes in:
  • Sputum volume/character
  • Breath sounds
  • Dyspnea score
  • Vital signs
  • Chest radiograph & ABG
  • Ventilator parameters (if intubated)

Documentation & Follow-Up

• Use protocol-based ACT orders.
• Chart should list:
  • Positions used & time in each
  • Patient tolerance
  • Effectiveness indicators
  • Adverse/untoward events observed