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