An overview of Cough

An Overview of Cough & Cough Assessment

Sally Cozens Respiratory Specialist Physiotherapy

ObjectivesRevision of normal cough function

Why assess cough?

How to assess cough the components of cough

When to introduce airway clearance methods

Understanding Airway Clearance Techniques

An introduction to MI-E

Specialists in Ventilation & Airway Clearance2Normal PhysiologicalCoughSpecialists in Ventilation & Airway Clearance3? move title up?Normal CoughSpecialists in Ventilation & Airway ClearanceCough is a forced expulsive manoeuvre, usually against a closed glottis and which is associated with a characteristic sound.(BTS 2006)

Coughing and support from the mucocilliary escalator protects the respiratory system by clearing it of irritants and secretions

Check you can see all text as slide showStages in a Normal Physiological CoughSpecialists in Ventilation & Airway Clearance(Yanagihara et al. 1966)Requirements For A Normal CoughSpecialists in Ventilation & Airway Clearance

6Glottis Specialists in Ventilation & Airway ClearanceGlottisEpiglottisVocal Folds/ CordsArytenoid CartilageTracheaAn Effective CoughSpecialists in Ventilation & Airway Clearance

(Leith 1985) Inspiratory Phase Compressive Phase Expiratory Phase

Check you can see all text as slide showNormal CoughSpecialists in Ventilation & Airway Clearance

Check you can see all text as slide showWhy Assess Cough?Specialists in Ventilation & Airway Clearance10? move title up?General muscle weaknessRespiratory muscle weaknessDecreased chest wall complianceShortening of respiratory muscles &Chest wall deformityDecreased tidal volumesREM related nocturnal hypoventilationNREM and REM related hypoventilationDaytime hypercapnic respiratory failureIneffective cough Recurrent chest infections

Disease Progression11Impact Of Impaired CoughSpecialists in Ventilation & Airway ClearanceEffective cough is a protective mechanism against respiratory tract infections, which are the commonest cause of hospital admission in patients with respiratory muscle weakness due to neuromuscular disease. (Chatwin et al 2003)

Check you can see all text as slide showImpact Of Impaired Cough Specialists in Ventilation & Airway Clearance90% of episodes of respiratory failure develop because of inability to clear the airways in NMD

(Gomez-Merino et al 2002) Check you can see all text as slide showWhat Numbers Are Significant?Specialists in Ventilation & Airway ClearanceIf PCF does not exceed 270-300L/min, Patients when they are unwell are at risk of a decline in their PCF < 160L/min

(Bach et al, 1997, Chest)

Check you can see all text as slide showImpaired Cough Specialists in Ventilation & Airway Clearance

Check you can see all text as slide showNMD Patient The RealitySpecialists in Ventilation & Airway Clearance

16Cough AssessmentSpecialists in Ventilation & Airway Clearance17? move title up?How Do We Assess The 3 Cough Phases?Specialists in Ventilation & Airway ClearanceNormal ValuesSpecialists in Ventilation & Airway ClearancePIMaxSNIPPEMaxPCFNormalValuesMen > 80 cmH2O

Women >70 cmH2O

(Koulouris et al 1988)Men >70 cmH2O

Women > 60cmH2O

(Miller et al 1985)

Men and Women >100 cmH2O

(Koulouris et al 1988)> 360 L/minStacatto ExpirationSpecialists in Ventilation & Airway Clearance

Cough Assessment How ?Specialists in Ventilation & Airway ClearanceAssessing PCF is a quick and easy way of measuring expiratory muscle function

The greater the PCF, the less risk of respiratory complications (Kang & Bach 2000

21Implications of Reduced PCFSpecialists in Ventilation & Airway ClearanceRecurrent chest infections

Risk of aspiration

Hospital Admissions

Reduced QoL

Respiratory Failure & Mortality22Which Patients May Be At Risk?Specialists in Ventilation & Airway Clearance(Canadian HMV Guidelines 2011)23Introducing Airway Clearance TechniquesSpecialists in Ventilation & Airway Clearance24? move title up?When To Introduce MethodsSpecialists in Ventilation & Airway ClearancePCF