Non Invasive Ventilation and Cough Assist Sarah Ewles

Non Invasive Ventilation and Cough Assist Sarah Ewles Clinical Specialist Physiotherapist SUHT

What is NIV? NIV is the use of either negative/positive pressure/ volume ventilation ( without the use of an endotracheal tube )to augment an individual’s ventilation and correct hypercapnic respiratory failure.

Non invasive ventilation (NIV) refers to the provision of ventilatory support through the patients upper airway using a mask or similar device (BTS Guidelines 2002)

History of NIV Iron lung 1929 -Drinker Ø Negative pressure devices-cuirass Ø Ø Polio outbreak 19381950’s

History of NIV Manual IPPV introduced 1952 -larssen and Ibsen Ø Negative pressure replaced by positive pressure Intensive care units Ø Successful application of nasal CPAP for OSA 1980’s Ø Improved mask design Ø Led to NIV being used in the ITU setting with COPD patients Ø

How did NIV start? Ø The demonstrated effectiveness of NIV in the treatment of acute COPD was a catalyst to respiratory clinicians all over UK learning the technique and they began to extrapolate the technique to the home/domiciliary setting for the long term treatment of hypercapnic respiratory failure.

How did NIV start? Ø With this came a change in indications for referral and patients are referred with a range of conditions for both acute and /or home ventilation. E. g. chest wall deformity, NMD, long term weaning from ITU.

Why Does NIV Work? Improves ventilatory mechanics Ø Rests fatigued respiratory muscles thereby improving strength and endurance Ø Enhances ventilatory sensitivity to CO 2 Ø Improves sleep stage distribution which may increase chemosensitivity and enhance sleep quality. Ø Hill, N Noninvasive ventilation: does it work, for whom, and how? Am Rev Respir Dis 1993; 147, 1050 -1055

Types of NIV Ø CPAP Ø BIPAP Ø PSV Ø PCV Ø VCV Ø AVAPS

Different types of NIV Ø CPAP • Continuous Positive Airways Pressure throughout both inspiration and expiration

Different types of NIV Ø Bi. PAP • • • Bi-level Positive Airway Pressure Delivers pre-determined positive pressure to a spontaneously breathing patient on inspiration and expiration Independent control of inspiratory and expiratory pressures

Bipap Ø IPAP • • Inspiratory positive airway pressure Pressure given on inspiration to increase tidal volume Ø EPAP • • Expiratory positive airway pressure PEEP

What are the indications for the use of NIV? Type II respiratory failure (Bilevel/PCV/VCV) l COPD l Obesity hypoventilation(OHS) l NMD l Chest wall deformity l Weaning from mechanical ventilation l Note consensus document NMD and COPD l PCO 2 >6 NMD PCO 2>7. 5 COPD CHEST 1999 Type I respiratory failure (CPAP) l Pulmonary oedema l OSA

• • What are the indications for the use of NIV? Treatment of nocturnal hypoventilation associated chest wall disease, muscle weakness and neurological disorders Weaning from invasive ventilation Bridge to transplant Cardiogenic pulmonary oedema Ventilatory support for patients that are not suitable for intubation and ventilation Acute on chronic respiratory failure with chest wall deformity or neuromuscular disease Acute pneumonia

What are the contraindications? Ø Undrained Pneumothorax Ø Severe hypotension Ø Severe bullous lung disease Ø Cardiac arrythmias Ø Neurological instability Ø Facial trauma ( for Nasal/Full Face masks)

Precautions to NIV • Copious bronchial secretions • Severe co-morbidity • Confusion/agitation • Upper gastrointestinal surgery • CVS instability • Lung abscess • Haematemesis • Proximal lung tumours

Evolution of respiratory failure in Neuromuscular disease/ restrictive lung disorders Natural history of the evolution of respiratory insufficiency in patients with neuromuscular disease. . NREM = non-REM; pred = predicted Simmonds AK, Chest. 2006; 130: 1879 -1886.

Possible Indications for NIV Support in NMD Patients When to Start NIV? To prevent respiratory decompensation To alter chest wall/lung growth characteristics During intercurrent chest infections For perioperative period/gastric tube placement During pregnancy To rest respiratory muscles To control nocturnal hypoventilation with or without symptoms Ø To treat established hypercapnic ventilatory failure Ø To palliate symptoms/end-of-life care Ø Ø Ø Ø

When should I consider domicillary NIV? Failure to wean from NIV (acute) Ø OSA (CPAP) Ø Hypercapnic respiratory failure secondary to Ø l l Ø Chest wall deformity SCI NMD Obesity hypoventilation syndrome COPD recurrent AHRF >3 episodes l Or intolerance of LTOT

Assessment for NIV Ø Domicilliary l l l ABGs (preferably early am) Spirometry Overnight oximetry Mouth pressure MIP/MEP (NMD) Symptoms

Interfaces Ø Nasal Masks Ø Full face masks Ø Nasal Pillows Ø Mouth piece Ø Tracheostomy

Nasal Masks Ø Advantages: • Speech • Patient can drink with mask on (machine must be switched off) • Allows effective clearance of secretions Ø Disadvantages: • Mouth closed • If talking with machine on machine can have difficulty synchronising with the patient’s breathing

Full face masks Ø Advantages: • Mouth can be open • Can use on the comatose patient • Can use on the mouth breathing patient Ø Disadvantages: • • • Claustrophobic Risk of aspiration Unable to effectively communicate More difficult to get adequate seal Can’t clear secretions

NIV and Palliative care ‘Just because a technique is available does not necessarily mean it should be used…. . much thought should be given before using NIV for palliation and the techniques should not be used indiscriminately in the dying’ Non-invasive ventilation and palliation: experience in a district general hospital and a review Palliative Medicine 2003; 17: 21 /26

Indications for NIV in palliative care Ø NIV can also be useful for providing time to clarify the diagnosis or response to treatment Ø To enable the patient to get well enough to get home Ø Patients and families are given extra time to come to terms with dying and achieve `closure’

Think first… Not all patients are able to tolerate NIV The technique may not be successful in confused people, and in coma and with bulbar problems it may not be possible to protect the airways Ø The masks can be uncomfortable and claustrophobic and can cause facial skin necrosis. Ø Intervention should be carefully assessed lest it become a barrier to communication between the dying patient and carers. Ø Ø

The aim of NIV is to palliate symptoms and not primarily to extend life. Non-invasive ventilation and palliation: experience in a district general hospital and a review Palliative Medicine 2003; 17: 21 /26

NIV in end stage COPD patients Ø NIV increases the tidal volume whilst reducing respiratory effort. Ø Support can be intermittent as well as continuous. Ø NIV can be offered as a palliative treatment for distress and breathlessness Ø Is it justified to use NIV to prolong survival if death is imminent anyway?

NIV in NMD Ø MND patients often report ‘choking attacks’ and poor sleep Ø Offered NIV nocturnally/domicillary use Ø Median survival of MND patients using NIV is about 10 months. Simonds AK. Neuromuscular disease. In Muir JF, Ambrosino N, Simonds AK eds. Non-invasive mechanical ventilation. European Respiratory Monograph 16. Shef- ®eld: European Respiratory Society, 2001: 218 /26. Ø Patients offered NIV are likely to live longer but with greater disability. Ø There is no evidence to support the prophylactic use of NIV in Duchenne’s dystrophy Raphael JC, Chevret S, Chastang C, Bouvet F. Randomised trial of preventative nasal ventilat ion in Duchenne muscular dystrophy. Lancet 1994; 343: 1600 /604.

Buying time Ø It may be necessary to start NIV whilst seeking to clarify the position. One can then decide whether NIV should be discontinued, continued with palliative intent or with full curative intent. Ø NIV was used as a life-prolonging measure and where it was felt the use allowed time to complete life-closure tasks. Freichels TA. Palliative ventilatory support : use of noninvasive positive pressure ventilation in terminal respiratory insuf®ciency. Am J Crit Care 1994; 3: 6 /10.

Terminal breathlessness Ø The role of NIV in treating terminal breathlessness is unclear Ø Not everyone can tolerate NIV, nor is breathlessness always helped in those who persevere on it.

NIV and caregivers Ø Concerns that NIV burdens caregivers and may affect patients Qo. L Ø Mustfa, N. , Walsh, E. , Bryant, V. , Lyall, R. A. , Addington-Hall, J. , Goldstein, L. H. , Donaldson, N. , Polkey, M. I. , Moxham, J. and Leigh, P. N. (2006) The effect of noninvasive ventilation on ALS patients and their caregivers. Neurology, 66, (8), 1211 -1217. 39 patients with ALS requiring NIV-26 established on NIV and 13 declined/could not tolerate Ø 21 caregivers of NIV patients questioned Ø Qo. L measurements for 12 months from caregivers and patients Conclusion Ø respiratory muscle weakness had greater effect on Qo. L that disease severity Ø NIV improved Qo. L despite disease progression Ø ‘. . NIV has no impact on caregiver Qo. L and doesnot significantly increase caregiver burden or stress’ Ø

Ethical issues Ø NIV had been ethical, as it had been used not for an inhumane prolongation of life but to facilitate emotional preparation for death. Freichels TA. Palliative ventilatory support : use of noninvasive positive pressure ventilation in terminal respiratory insuf®ciency. Am J Crit Care 1994; 3: 6 /10. Ø Patients had experienced a pivotal clinical deterioration months before the need for NIV arose and that lifeclosure tasks could have been completed better outside the acute hospital setting. Clarke DE, Vaughan L, Raf®n TA. Non-invasive positive pressure ventilation for patients with terminal respiratory failure: the ethical and economic costs of delaying the inevitable are too great. Am J Crit Care 1994; 3: 4 /5. 26 Ø NIV should not be used needlessly to prolong life in a patient who is clearly dying.

Ethical issues Ø In chronic conditions such as COPD, severe heart failure or neuromuscular weakness it is not always clear whether or not death is imminent, and `active’ and palliative treatment may coexist. Ø Patients will often decide when they no longer want NIV and request discontinuation Ø If a mentally competent patient desires to stop NIV, there is no ethical reason why it should not be discontinued. Polkey MI, Lyall RA, Davidson AC, Leigh PN, Moxham J. Ethical and clinical issues in the use of home noninvasive mechanical ventilation for the palliation of breathlessness in motor neurone disease. Thorax 1999; 54: 367 /71.

The Cough Assist

Components of Coughing Ø Ø Ø Ø Ø Stimulus of mainly vagus nerve -reflex or voluntary Inspiratory gasp -up to VC (> 1. 5 litres) Sudden glottis closure Expiratory muscle contraction-generating thoraco-abdominal pressures of up to 100 cm. H 20 (0. 2 secs) Sudden glottis opening Explosive flow of air –achieving between 2. 7 to 20 litres/sec of flow Natural cough reaches peak pressures of up to 150 cm/H 2 O (500 miles per hour) Narrowing of trachea, increases shearing force Assists natural removal of Bronchial secretions

Problems of Ineffective Coughing Ø Sputum Retention Infection Ø Atelectasis Sepsis Ø Increased WOB Respiratory Failure Ø Hypoxaemia Hospitalisation Ø Aspiration Death

Rationale Ø Clears sputum, preventing retention, atelectasis and their associated problems Ø Maintains compliance of thorax Ø Maintains length of respiratory muscles Ø Preserves strength of cough Ø Reduces hospital admissions Ø Increases survival

High Risk Patients CNS capacity load Balance between load, capacity and drive in ventilatory failure

Peak Cough Flow Ø Measurement of cough effectiveness Ø Peak flow meter and cushioned facemask Ø Assess best of 3 Ø Need at least 2 people

Rationale for Prophylactic Treatment with cough assist Evidence to date in NM disease states that : l Techniques which increase lung volume, should be commenced when the PCF is <160 l/min, and should be considered below 270 l/min l Manual assisted coughing should be incorporated when VC drops to 50% predicted or <1. 5 litres l Treatments should be 10 -15 breaths x 3 day

Cough Assist Ø Increases inspiratory volume and increases expiratory flow Ø Delivers gradual positive inspiratory pressure followed by a rapid shift to negative expiratory pressure simulating a cough

What does it Do? Ø The machine mimics a natural cough, for those patients who can not do this

Auto vs Manual Auto Ø triggers and cycles based on times the user sets (Like Bi. PAP but NO Autotrak) Manual Ø has no time triggering or cycling, done by user or carer.

Using the Device Ø First use Manual Mode (to get used to the sensation) Ø 10 cm/H 20 starting pressure (hand over tube) Ø Start in Low Flow setting(1/3 of the high flow setting)

Using the Device Ø Place mask on patient and switch to Inhale Ø Switch to Exhale when patient is ready to breathe out Ø Back to inhale when patient needs to breathe in l Move to Automatic mode only if comfortable and appropriate

Using the Device Ø Automatic Mode: l Inhale: Exhale: Pause l Adjust to comfort of patient l l 2 seconds 1 second

Using the Device Ø Three to Five breath cycles, then rest Ø Suction or clear secretions manually Ø Do this 5 to 10 times

Using the Device Ø How often and when? l l Depends on condition Every 20 minutes if severe, less if not Try not to use for 2 hours after feeding Assess via lung sounds

Contra-Indications Ø Existing Barotrauma or Pneumothorax Ø Intolerance to the machine Ø Spinal shock patients, consider only once stabilised Ø Be aware that on average therapy can raise systolic BP by 8 mmg and Diastolic by 4 mmg. Also potential that HR may increase

Ø More info: www. coughassist. com

References Ø BTS Guidelines 2002 Ø Hill, N Noninvasive ventilation: does it work, for whom, and how? Am Rev Respir Dis 1993; 147, 1050 -1055 Simmonds AK, Chest. 2006; 130: 1879 -1886. Ø Ø Shee C and Green M Non-invasive ventilation and palliation: experience in a district general hospital and a review Palliative Medicine 2003; 17: 21 /26 Ø Simonds AK. Neuromuscular disease. In Muir JF, Ambrosino N, Simonds AK eds. Non-invasive mechanical ventilation. European Respiratory Monograph 16. Shef- ®eld: European Respiratory Society, 2001: 218 /26. Ø Raphael JC, Chevret S, Chastang C, Bouvet F. Randomised trial of preventative nasal ventilat ion in Duchenne muscular dystrophy. Lancet 1994; 343: 1600 /604. Ø Freichels TA. Palliative ventilatory support : use of noninvasive positive pressure ventilation in terminal respiratory insuf®ciency. Am J Crit Care 1994; 3: 6 /10. Ø Clarke DE, Vaughan L, Raf®n TA. Non-invasive positive pressure ventilation for patients with terminal respiratory failure: the ethical and economic costs of delaying the inevitable are too great. Am J Crit Care 1994; 3: 4 /5. 26 Ø Polkey MI, Lyall RA, Davidson AC, Leigh PN, Moxham J. Ethical and clinical issues in the use of home noninvasive mechanical ventilation for the palliation of breathlessness in motor neurone disease. Thorax 1999; 54: 367 /71. Ø Mustfa, N. , Walsh, E. , Bryant, V. , Lyall, R. A. , Addington-Hall, J. , Goldstein, L. H. , Donaldson, N. , Polkey, M. I. , Moxham, J. and Leigh, P. N. (2006) The effect of noninvasive ventilation on ALS patients and their caregivers. Neurology, 66, (8), 1211 -1217.

Contact Ø Bleep 2080 at SUHT via switchboard Tel: 02380 777222 Ø Sarah. Ewles@suht. swest. nhs. uk Ø The Respiratory Centre, SUHT Tel: 02380 794325