PPC

Acknowledgements

• Marita Dale and Carolyn Gates

Learning Outcomes

By the end of this lecture, students should be able to:

• Recall material covered in ASPA on secretion clearance, including:

  • Clinical assessment findings suggesting a secretion movement impairment

  • Selected treatments & mechanism of action

• Understand the pathophysiology behind secretion movement impairments in order to further define them and apply this understanding in clinical scenarios.

Subjective Assessment Findings Suggesting a Secretion Movement Impairment - Revision

• Does the patient have a history of:

  • Respiratory diseases such as COPD, asthma, or chronic bronchitis?

  • Significant smoking history or exposure to environmental pollutants?

  • Frequent cough or sputum production? If so, consider asking further:

    • Is the cough productive?

    • What is the color and consistency of the sputum?

    • Do they experience any associated symptoms such as wheezing or shortness of breath?

Objective Assessment Findings Suggesting a Secretion Movement Impairment - Revision

Signs Suggestive of Secretion Movement Impairment:

• Observation:

  • Assess sputum for amount, color (e.g., green for infection, clear for allergies), and viscosity (thick vs. thin) that can indicate the presence of secretions and the state of pulmonary health.

• Palpation:

  • Palpable fremitus, which refers to the vibration felt on the chest wall when a patient speaks, can indicate areas of consolidation or obstruction due to secretions.

• Listening:

  • Note audible noises during respiration, including any wheezes, crackles, or stridor.

  • Auscultation reveals abnormal breath sounds, while cough evaluated for effectiveness helps identify secretion retention:

    • Coarse crackles often indicate secretions in the airways.

  • Consider using a stethoscope to listen for pattern changes in breath sounds during coughing or sighing.

• Moist CXR and ABGs (Arterial Blood Gases) can provide insight into gas exchange efficiency, further highlighting potential secretion retention or lung function issues.

• Spirometry:

  • Consolidation or collapse can be indicated by decreased PaO2 and increased PaCO2 levels.

  • An obstructive pattern may indicate blocks due to secretions, warranting further analysis.

Benefits of Secretion Clearance

• Reduces risk of pulmonary infections by clearing pathogens trapped in secretions.

• Aids in the maintenance of effective breathing mechanics, avoiding deterioration such as:

  • Decreased Work Of Breathing (WOB), which is crucial for patient comfort and recovery capacity.

• Improves ventilation through effective gas movement, enhancing oxygen and carbon dioxide exchange at the alveolar level, thus maintaining homeostasis.

Selected Treatments and Mechanism of Action

1. Techniques to facilitate secretion movement & removal:

   • Postural drainage helps utilize gravity to assist in clearing secretions from different lung lobes.

   • Percussion breaks up mucus in the airways, making it easier to expel.

   • Vibrations/Shaking apply external pressure to the chest wall to decrease viscosity in the airway secretions.

   • Mobilisation/Exercise supports airway clearance through increased respiratory muscle engagement and secretion movement.

   • Coughing and Huffing techniques can further mobilize secretions effectively, utilizing specific expiratory strategies to maximize outcomes.

Physiology of Huff & Cough

• Huff:

  • A technique aimed at maintaining airway patency while generating airflow, particularly useful for patients unable to tolerate a full cough.

  • Initiate from a medium to high lung volume, permitting greater release of airway secretions.

• Key Concepts:

  • 2-Phase Gas-Liquid Flow: Highlights the interaction between airway secretions and airflow, essential for effective clearance.

  • Cough has higher expiratory flow rates, demonstrating properties of mist flow, while Huff's flow is characterized by lower rates, yielding a more annular flow that effectively clears secretions without airway collapse.

Dynamic Compression

• Forced Expiration:

  • Understand that airway narrowing occurs during forceful expiration, specifically influenced by the Equal Pressure Point (EPP).

  • Dynamic Compression:

    • High airflow velocity results in a significant gas-liquid interaction, which is critical in facilitating secretion movement.

    • In mist flow, shearing of the protective mucus layer can occur, potentially complicating retention situations.

Equal Pressure Point (EPP)

• EPP is where intrapleural pressure (Ppl) equals alveolar pressure (Pal), identifying critical dynamics in forced expiration.

• AIRWAY narrowing occurs towards the mouth of the EPP, which can lead to dynamic compression with ineffective clearance of secretions during coughing.

• EPP Characteristics:

  • Low Lung Volume Huff: EPP is positioned closer to the alveoli, making secretions harder to mobilize.

  • High Lung Volume Huff (or cough): Generally positions lungs for better secretion evacuation due to increased pressure forcing air behind obstructive material.

Summary of Equal Pressure Point (EPP) Insights

• Diagrams illustrate the relationship between pressures effectively:

  • EPP can be represented via the equation:
    EPP: Pal = Ppl + Pel

  • Greater elastic recoil resulting from higher lung volumes can influence the central and peripheral movement of secretions, proving vital during therapeutic interventions.

Defining Secretion Movement Impairments

• Secretion Movement vs Gas Movement: It's imperative to differentiate the mechanisms impacting lung function, setting a foundation for tailored interventions.

• Lung Clearance Mechanisms:

  1. Mucociliary clearance (MCC) ensures consistent removal of small particles.

  2. Cough serves as a backup, particularly necessary when MCC is compromised.

  3. Alveolar Clearance assists in the elimination of pathogens and particulate matter from the deepest lung reaches.

• Components of Mucociliary Clearance:

  • Ciliary activity is essential for lifting mucus efficiently and maintains respiratory hygiene.

  • Mucus layer quality greatly impacts the effectiveness of MCC, with changes indicating possible pathologies.

Factors Affecting Mucociliary Clearance

• Evaluate factors surrounding secretion movement problems, thoroughly assessing for:

  1. Reduced secretion movement impairment:

     • Is it stemming from:

       • Impaired MCC?

       • Reduced cough effectiveness?

       • A combination of both?

Pathophysiology of Reduced Secretion Movement

Possible Causes of Reduced Cough Effectiveness

• Factors include:

  • Reduced inspiratory capacity (e.g., issues like pain from chest injuries).

  • Inability to effectively close the epiglottis can lead to aspiration risk or lack of pressure needed for effective cough.

  • Weak muscles related to reduced expiratory force (e.g., due to poor conditioning or debilitation).

  • Poor understanding or technique of huff/cough mechanics, leading to ineffective performance.

  • Presence of floppy or unstable airways, decreasing the effectiveness of forceful exhales.

Possible Causes of Reduced Mucociliary Clearance

• CILIA:

  • Decreased activity, beat frequency, or overall number of cilia can impair secretion transport.

  • Ciliary damage may arise from environmental exposure, illness, or toxins, significantly affecting overall respiratory function.

• MUCUS:

  • Increased mucus load or viscosity and a diminished sol layer can hinder the normal clearance process, resulting in stagnation and infection.

Effects of Smoking on Secretion Movement

• CILIA:

  • Damage leads to decreased ciliary beat frequency, drastically reducing mucociliary clearance efficiency.

• MUCUS:

  • Increased secretion volume and viscosity are a result of mucus gland hypertrophy, contributing to obstruction and impaired flow.

• AIRWAYS:

  • Inflammatory responses lead to smooth muscle hypertrophy and a loss of elasticity, directly obstructing airflow.

• ALVEOLI:

  • Dysfunction of alveolar macrophages increases susceptibility to pathogens and results in destruction of alveolar structures, critical for gas exchange.

Consequences of Reduced Secretion Movement

• Secretion Retention:

  • Significant obstruction can lead to alveolar filling, drastically impairing ventilation/perfusion (V/Q) matching.

  • A declining surface area for gas exchange precipitates reduced PaO2 levels and potential hypoxemia.

  • Increased respiratory workload decreases overall alveolar ventilation, leading to hypoxemia and the possibility of respiratory failure.

• Retention Effects:

  • Poor gas movement results in heightened airway resistance, exacerbating the hypoxemia and hypercapnia often seen due to inadequate carbon dioxide (CO2) clearance.

Learning Outcomes for Subsequent Sessions

By the end of this session, students should be able to:

• Understand and effectively utilize various treatment techniques for managing secretion movement impairments, including:

  • Forced Expiratory Technique (FET) to enhance airway clearance.

  • Active Cycle of Breathing Technique (ACBT) that fosters independence in secretion clearance.

  • Positive Expiratory Pressure (PEP) devices which create resistance for facilitating secretion removal in airways.

  • Explore additional adjuncts to secretion clearance techniques like nebulizers, suctioning, and exercise to optimize therapy effectiveness.

Treatment Techniques Overview

Forced Expiratory Technique (FET)

• Purpose:

  • Implement FET to maintain breathing control, minimizing bronchospasm while aiming to optimize oxygen saturation recovery during episodes of airway cleaning.

• Phases:

  1. Initiating Breathing control (BC) to regulate airflow.

  2. Performing 1-2 huffs, initiating forced expiration to mobilize secretions.

  3. Returning to Breathing control (BC) to stabilize the airway post-clearing maneuvers.

• Huff Options:

  • Execute either 1-2 high lung volume huffs or a combination of 1 low and then 1 high lung volume huff.

  • It may stimulate spontaneous coughing or necessitate patient-initiated coughing response for comprehensive clearance.

Active Cycle of Breathing Technique (ACBT)

• Definition:

  • An active breathing technique that empowers patients to participate in clearing their sputum, bolstering independence in managing their respiratory health.

• Components:

  • ACBT incorporates FET coupled with thoracic expansion exercises (TEE) in dynamic combinations designed for maximized effectiveness.

• TEEs:

  • Rolling through deep breaths aiming for Total Lung Capacity (TLC), often initiated with individualized inspiratory patterns from the patient’s own respiratory rhythm.

  • Typically combines 3-5 TEEs successively to enhance collateral ventilation and re-open areas of collapse post-FET application.

Positive Expiratory Pressure (PEP) Devices

• Function:

  • Designed to introduce resistance against expiratory flow, thus facilitating superior secretion clearance from the airways.

  • Devices create positive expiratory pressures typically through masks or mouthpieces to aid in effective secretion removal.

• Effectiveness:

  • Assists small airway stability and permits therapeutic air to penetrate and dislodge secretions, enhancing overall respiratory function.

Oscillating PEP Devices

• Functionality combines PEP resistance with airflow oscillation, designed to further promote mucociliary clearance (MCC).

  • Examples such as Bubble-PEP, Acapella, and Flutter devices employ mechanisms effectively by generating resistance while introducing oscillatory airflow to improve secretion clearance.

Adjuncts to Secretion Clearance

• Nebulisers/Inhaled Therapies:

  • Devices efficiently convert liquid medications into aerosol droplets, enhancing delivery effectiveness for treatments including mucolytics, bronchodilators, and corticosteroids.

• Exercise:

  • Regular physical activity enhances expectoration rates, increases expiratory flow rates, and fosters changes in mucus consistency to optimize clearance.

Suctioning

• Definition:

  • Mechanical aspiration of pulmonary secretions, particularly applied to patients with artificial airways or those unable to clear secretions independently.

• Procedure:

  • Employ negative pressure gently while withdrawing the catheter to maximize effectiveness and minimize discomfort.

• Indications:

  • Necessary when signs of secretion retention are present, including ineffective cough, noisy breathing, and abnormalities in ABGs that point to ventilation issues.

Categorization of Suctioning Types

• Intubated:

  • Relevant to conditions requiring endotracheal tubes or tracheostomy interventions to ensure effective clearance.

• Non-Intubated:

  • Includes oropharyngeal, nasopharyngeal, or mini-tracheostomy approaches to suctioning based on the patient’s needs and clinical presentation.

Precautions and Contraindications for Suctioning

• Must consider uncontrolled intracranial pressures, severe bronchospasm, and active bleeding as absolute contraindications.

• Equipment Required:

  • Various suction catheters (sizes depending on the patient), personal protective equipment (PPE), supplemental oxygen equipment, and monitoring devices must be on hand for safety and to ensure effective care.

Complications and Adverse Effects of Suctioning

• Potential respiratory complications can manifest as hypoxemia, mucosal trauma, and risk of infections, further compounded by cardiovascular and neurological ramifications resultant from invasive procedures.

Evaluating Effects of Treatment to Increase Secretion Movement

• Assess both subjective reports (patient feedback on symptoms and changes) and objective measures (palpation findings, auscultation results, cough efficacy, sputum quality, and blood gas levels) to evaluate treatment efficacy and ensure continued progress in clinical outcomes.