BREAS MEDICAL
Cough Assist Systems and Ventilators
Breas NIPPY Clearway Mechanical Insufflation-Exsufflation Clinical Guidelines Rev 2-1
Clinical Guidelines
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CLINICAL GUIDELINES
CLINICAL GUIDELINES Mechanical Insufflation-Exsufflation (MI-E) Airway clearance techniques (ACT’s) can be divided it to proximal and peripheral airway clearance techniques 1,2 . Proximal ACT’s (cough augmentation) clear secretions from the central airways. Peripheral ACT’s (secretion mobilising) move secretions from the small airways towards the central airways. All patients should be assessed by a respiratory physiotherapist / respiratory therapist and the most appropriate ACT should be performed. The therapist should in the first instance measure the cough peak flow (CPF). Dependent on the CPF results use the most appropriate treatment. For example, if the patient has a CPF of 280 L/min using a lung volume recruitment (LVR) bag or glossopharyngeal breathings (GPB) should augment an effective cough. However if the CPF is 180 L/ min then mechanical insufflation-exsufflation (MI-E) would be the treatment of choice (see Figure 1 modified from 1). Tips and Tricks about the usage will depend on what treatment mode and therapy, you are delivering. To avoid confusion this clinical guideline will be split up into the 4 therapy modes:
Figure 1 shows, what airways clearance techniques are most useful depending on the individuals forced vital capacity (FVC), FVC as a % predicted (FVC(%)) or cough peak flow (CPF). Techniques that can be utilised include: mechanical insufflation-exsufflation (MI-E), manual assisted cough (MAC), mechanical insufflation utilising a lung volume recruitment (LVR) bag or self-insufflation by glossopharyngeal breathing (GPB).
1. Mechanical insufflation-exsufflation (MI-E) 2. MI-E with the addition of oscillation therapy 3. Intermittent positive pressure breathing 4. Non-invasive ventilation (NIV) Where MI-E is the treatment of choice you can start treatment with the Clearway 2. This document is intended for clinician use only and devices shall be set up by a competent clinician. This document does not replace the Clearway 2 User Manual. Please always refer to the User Manual before using the Clearway 2. page 1 of 12
For more information, visit Education by Breas
1. Mechanical insufflationexsufflation (MI-E) mode
CONSIDERATIONS BEFORE USING MI-E • Review the contraindications to using this treatment
MI-E is a proximal ACT 1,2 . The aim of MI-E is to enhance cough expiratory flow. By increasing the speed of the expiratory flow along with expiratory volumes, enhanced secretion movement occurs in the central airways and facilitates secretions to be cleared from the mouth. Thereby increasing cough strength. This occurs by delivering a set positive pressure (insufflation) and cycling rapidly to negative pressure (exsufflation).
• Are you competent to use the device and have you received training? Clearway 2 training can be found at Education by Breas – Airway Clearance Training • Where indicated, do you have cardiovascular monitoring available and consider the correct environment for the initiation of MI-E (home, ward, HDU or ICU)?
As an example, the Clearway 2 MI-E mode is intended to be used in patients with respiratory muscle weakness typically neuromuscular disease, including but not limited to the following patient groups as this is where the evidence base is:
• Is there a suction equipment available? • With any airway clearance technique, including MI-E, there is the potential to mobilise a large amount of secretions and therefore it is important to ensure that the appropriate emergency equipment (e.g. resuscitation bag and suction) is available in case of mobilising a large mucus plug into a central airway.
• Motor neurone disease / Amyotrophic lateral sclerosis • Post-Polio syndrome • Spinal cord injuries
• Do you have the correct circuit and interface for use for your patient? For more information, visit Education by Breas – Clearway 2 – Getting Started
• Muscular dystrophy • Other neurological disorders
• Test the MI-E device prior to use. • Decide which interface you will use, a full-face mask in patients who are using the device noninvasively or a catheter mount for those who have a endotracheal tube or tracheostomy.
CONTRAINDICATIONS FOR USE OF THE MI-E There are contraindications to the use of MI-E mode. This is a suggested list but not be exhaustive. Careful evaluation of the patient will need to occur prior to commencement of treatment:
• Is oxygen required? You may entrain up to 15 litres of low-pressure oxygen, remember to entrain the oxygen via a 22m-22F straight connector with 6 mm side arm. Place this at the patient end and always turn the oxygen on after the MI-E device is turned on and turn oxygen off prior to turning the device off.
• Patients with a history or risk of bullous emphysema • Patients with a history or are susceptible to pneumothorax or pneumo-mediastinum
• Ensure that an anti-bacterial filter is used to protect the patient and machine against any microorganisms.
• Patients with cardiovascular instability • Patients with tracheoesophageal fistula • Recent or existing barotrauma • Spinal instability • Acute pulmonary oedema • Recent oesophageal surgery
SUGGESTED GUIDELINE FOR USE OF MI-E MODE: TITRATION & PREPARATION
• Increased intracranial pressure
For the initial titration session, we recommend the following
• Active, untreated tuberculosis
• Acute lung injury • Facial trauma • Active haemoptysis and frank haemoptysis • Fractured ribs with flail segments
CAUTIONS • Patients with bulbar insufficiency may be treated using MI-E but, caution should be taken and a risk assessment carried out prior to use • Nausea or risk of vomiting • Enteral feeding
• Monitor heart rate and oxygen saturations. Oxygen saturations and heart rate can be monitored with the addition of an oxygen saturation probe. • Ensure that the appropriate emergency equipment (e.g. resuscitation bag and suction) is available in case of mobilising a large mucus plug into a central airway. • Have oxygen available to you if this is an acute set up and the patient is requiring oxygen. Ask the patient to cough with the mask and tubing on. With your settings, you are aiming to increase the audibility of your patient’s cough, i.e. the louder the cough the stronger the cough. You will also be able to look at the CPF generated during the procedure. Please see suggested algorithm for an initiation of MI-E in automatic mode (see Figure 2). (For more information, visit Education by Breas – Insufflation-Exsufflation Cough Assistance Neuromuscular Disease). This allows the device to be used by one therapist or carer and facilitates transition to long-term use.
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If the patient is unable to use the device in automatic mode then use step one and two to set the pressure and control the timings manually. If you are using the Clearway 2, consider the TreatRepeat® function (For more informatioan about the practicalities of this feature, visit Education by Breas – Clearway 2 – Using TreatRepeat). TreatRepeat® allows you to record a treatment session that is individualised to that patient. You can then load the recorded profile and then it is ready for treatment.
Whilst using MI-E your patient should be continually re-examined and secretions clearance monitored. Where a patient cannot expel their own mucous, secretions should be removed using an external suction device via the mouth or tracheostomy tube. If needed use the NIV mode posttherapy to allow your patient to rest, reduce their work of breathing and re-recruit if required.
Figure 2 shows, suggested algorithm for the initiation of mechanical insufflation-exsufflation. (For more information, visit Education by Breas – Insufflation-Exsufflation Cough Assistance Neuromuscular Disease)
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The Clearway 2 has SynchronyBeep®, this can help to coordinate the patients cough to the start of exsufflation. After each cough or change of settings the Clearway 2 will measure the CPF. You can review this to see if there has been an increase in expiratory flows during the patient’s cough. Please note that an increase in CPF may not be indicative of an improvement in cough in patients with upper airway dysfunction. This is because CPF is a measurement of expiratory flow and this will continue to increase with increasing exsufflation pressures 3 . Indicating manual titration with patient feedback is key and this has also been supported by others 4 . An alternative for improving titration without direct access to the upper airway may be to evaluate the flow and volume traces to evaluate for upper airway collapse 3 (see Figure 2B).
Figure 2B: Value of Flow Volume Curve Profiles in Detecting Upper Airway Collapse 3 The figure shows examples of each of the 3 flow-volume curve profiles (A, B and C) during titration of the negative exsufflation pressure applied during mechanical in-exsufflation. (A) No UAC: PCF and the effective cough volume (ECV) increase. (B) UAC occurs at a specific exsufflation pressure (in this example at –50 cmH 2 O, confirmed at –60 cmH 2 O): PCF increases, ECV decreases. (C) UAC is observed at the beginning of pressure titration: PCF increases, ECV remains stable when expiratory pressure decreases. See the Results section for more details. ECV = effective cough volume, UAC = upper airway collapse
Amyotrophic lateral sclerosis (ALS) patients may benefit from a modified regime. This maybe more important in those with a bulbar phenotype. Please see suggested modifications for optimising MI-E in patients with ALS (see Figure 3). To enable the trigger to be set on the Clearway 2 change the sub mode to Programmed Mode setting the iTrigger® function to ensure the patient is triggering the device.
OTHER SETTINGS CONSIDERATIONS When setting the insufflation and exsufflation pressure, start low and titrate up as per the suggested settings algorithm. When using MI-E with artificial airways (tracheostomy and endotracheal tubes) higher insufflation and exsufflations pressures are required to overcome the resistance of the narrowed artificial airway 6 . In weak patients higher pressures may be required 7. Lung model studies have shown that peak expiratory flows are increased with higher exsufflation pressures 8,9 . Longer inspiratory times compared to expiratory times are required to allow equilibrium between the device and the alveoli 8,9 . More recently it has been suggested that decreasing the inspiratory flow enhances the peak inspiratory flow to peak expiratory flow ratio and increases an expiratory flow bias and enhance secretion movement 10 . Lung models use a ridged tube to represent the airway. In humans the airway is flexible and a more recent study that evaluated the effect of the airway using a “collapsible tube” versus a ridged tube (no-collapsible) found the collapsible tube increased peak expiratory flow more in exsufflation than a non-collapsible tube 11. However, these consepts have not been evaluated fully in humans and the exact implication is unknown. Now the insufflation and exsufflation settings are optimised along with timing setting you may wish to use an advanced MI-E mode. These allow you to set a set number of insufflations prior to an exsufflation. For more than one insufflation prior to exsufflation, with the option to repeat the cycle, select Programmed Mode. Using more than one insufflation may assist with secretion mobilisation. You may also add post exsufflation breaths if you are concerned about taking patients into their closing volumes. Alternatively you can perform re-recruitment breaths manually via the controller. Often patients need different settings for when they are well and unwell. The Clearway 2 for example, has the ability to set 4 different profiles. This means that you can set different profiles for when your patient is well or unwell and for other situations. An additional feature in case you use the Clearway 2 is Stepped Insufflations. This feature provides a set amount of insufflations which start at 50% of the set insufflation pressure and build up to the set pressure. This feature can be particularly useful if the patient needs to acclimatise to the desired insufflation pressure or if you are using the device to give a chest wall stretch. Possible side-effects of MI-E MI-E is a widely used therapy. However, there are some minimal but reported side-effects in the literature to be aware of when using MI-E. Pneumothorax: It is a relative contraindication for patients who are known to be susceptible to pneumothoraxes to be treated with MI-E 12-15 . It is a considered recommendation that ventilator users who are also using MI-E, and who have increasing dyspnoea or who require increasing positive inspiratory pressures with regard to their ventilation, should be evaluated for pneumothorax 12-15 . Bloating: There have been reports of nausea and abdominal distension/bloating when using MI-E in a few cases 14-16 . This may cause patients to discontinue with therapy. However, MI-E is considered to be a safe and effective treatment which is well-tolerated by the majority of patient groups 14-16 .
Figure 3 shows Suggested Modifications for Bulbar Motor Neurone Disease Patients adapted from Andersen et al. 5
Glottic closure: This has been reported to be a side effect in patients with bulbar motor neurone disease 5,17 and in other neuromuscular disorders 3 . if this is a problem for your patient follow the suggested algorithm in Figure 3.
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There have also been unsubstantiated reports that the addition of oscillations to insufflation and exsufflation may prevent glottic closure during exsufflation.
SpO2 <95% on room air +/- NIV
ACUTE SETTING CONSIDERATIONS Patients may be receiving supplementary oxygen therapy with or without ventilatory support. If the patient is unable to maintain their oxygen saturation without supplementary oxygen therapy this should be entrained into the MI-E device for treatment. Entrain oxygen if required and appropriate. When using a mask it is recommended that oxygen be entrained into the mask. You may wish to use the device in manual mode. This will allow you to adapt to a rapidly changing respiratory rate titrate as per the suggested algorithm for set up steps 1 and 2 but use the manual button to deliver the insufflation and exsufflation. Whilst using MI-E your patient should be continually re-examined and secretion clearance monitored. Where a patient cannot expel their own mucous, secretions should be removed using oral or nasopharyngeal suction where indicated or suction via the artificial airway if in situ. Patients with NMD’s usually do not have chronic lung disease. Therefore you would expect an oxygen saturation of greater than 95% on room air. If your patient has an oxygen saturation of < 95% this potentially indicated atelectasis and potentially sputum plugging. It is therefore recommended that MI-E treatment be commenced to clear secretions and return oxygen saturations to > 95%. With this approach improved survival has been reported 18-19 . Patients have also reported that MI-E was preferential to suction 20 despite no greater yield in sputum production 21 . However, one report stated higher exsufflation pressures cleared more secretions than lower exsufflation pressures in the intubated patient 22 . When extubated from mechanical ventilation the following approach has been shown to increase extubation success in NMD patient 23,24 and in patients who were intubated to various other reasons on the ICU 25 . Figure 4 shows a possible method to enhance extubation success in patients with NMD’s and Figure 5 is a suggested treatment for an acute respiratory tract infection in patients with NMD’s.
Figure 4 shows possible strategy for extubation and airway clearance in neuromuscular disease.
Rest MI-E
SpO2 >95%
Figure 5 shows suggested timing of MI-E depending on oxygen saturation in patients with neuromuscular disease.
PAEDIATRIC PATIENT CONSIDERATIONS MI-E can be used in small children, depending on the age and condition of the child 26 . There are reports of clinical use in infants as young as 3 months old. One needs to be aware that infants have limited collateral ventilation and are nearer to their physiological closing volume 16,19,27-29 . Pressures should start low and be titrated up as per the suggested set up algorithm until chest and abdominal wall movement indicates a deep breath in. Physiologically, children do not breathe in as long or out as long as adults 30 . The length of their cough will also be reduced: therefore, you will need to adjust your insufflation and exsufflation time accordingly. In a European survey of practice of MI-E in children reported insufflation times for children 0–2 years were a mean (SD) 1.4 (0.5) seconds with a range of 1–2.5 seconds 31. When a lung model imitating a one year old child with NMD (10 kg) was used to evaluate optimal times and pressures in the paediatric group highest CPF and insufflation volume were achieved with higher pressures > 30 cmH2O 9 , with asymmetrical pressures enhancing outcomes further 9 . Prolonging the insufflation time from 0.5 to 1 second, from 1 to 1.5 seconds, and from 1.5 to 2 seconds resulted in increases in CPF and inspiratory volume with no further increase over 2 seconds 9 . Therefore a good place to start is around 1.0 second, obviously if you are worried that this is too long for your patient start at 0.5 seconds and build up. Care needs to be applied with MI-E in infants, where the chest wall is very compliant and the closing volume of the lung is high as this can induce atelectasis, especially with long exsufflation times 32 . Please see Education by Breas for a sugested algorithm for the initation of infants and children with MI-E. Infants and severely weak children may find MI-E uncomfortable if you have taken them below their closing volume and not helped them re-recruit 32 . An insufflation after exsufflation can help prevent this and can be added in the Programmed Mode or, if the device allows for it, NIV Mode can be used. With any airway clearance technique, including MI-E, there is the potential to mobilise a large amount of secretions and therefore it is important to ensure that the appropriate emergency equipment (e.g. resuscitation bag and suction) is available in case of mobilising a large mucus plug into a central airway. Oximetry should be monitored in infants during treatment and is recommended in all children who are severely weak during an acute hospital admission.
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A sudden drop in oxygen saturation from baseline is highly likely to indicate that a large amount of secretions has been moved and oral or nasopharyngeal suction is warranted. If oxygen saturations do not improve immediately and secretions are no longer an issue, and if on assessment there are decreased air breath sounds, potential complication of a pneumothorax should be considered and the medical team should be alerted 12-15 . The resting energy of sick children is high and transient periods of oxygen therapy may be warranted during airway clearance 30 . Infants and children are often unable to co-ordinate or synchronise with complex programmes. Therefore you may find optimal synchronisation using simple cycling between insufflation and exsufflation with a short pause. This can help move the secretions up towards the mouth when a simultaneous cough may occur, further assisting clearance. Continually reminding the child that a deep breath is coming in followed by a cough also improves synchronisation. For community use of MI-E, a programmed setting enables treatment of the infant or child by one person. In community use of MI-E, modes not required should be set to ‘off’ in the menu to ensure the correct modes only are available for use.
SPINAL INJURY PATIENTS’ CONSIDERATIONS In high cervical spine injuries (C1 to C4), pneumonia is the primary complication, followed by atelectasis. In lower cervical spine injuries (C5 to C8), atelectasis remains a problem and pneumonia is a problem but to a lesser degree 33 . When using MI-E for the first time with a patient with SCI, it is crucial to monitor them cardiovascularly. Autonomic dysreflexia (AD) is a complex symptom that arises from a noxious or intense stimulus below the level of injury that leads to an unopposed discharge of the sympathetic nervous system. This sympathetic discharge cannot be modulated from higher cerebral centres and often results in hypertension. A reflex bradycardia is classically observed in many cases as a compensatory response because the carotid baroreceptors stimulate an increase in vagal tone, however tachycardia may also be seen 34 . As mechanical insufflation-exsufflation will cause changes in the patient’s intrathoracic pressure which may stimulate AD and the patient may be unaware of their symptoms, it is prudent to cardiovascularly monitor SCI patients when initiating MI-E treatment. Patients with acute cervical spine injury can experience bronchospasm, even in individuals without a prior history of asthma, because of autonomic changes seen in acute injury 35 . MI-E can exacerbate bronchospasm. Patients with acute cervical spine injury can experience bronchospasm, even in individuals without a prior history of asthma, because of autonomic changes seen in acute injury 35 . MI-E can exacerbate bronchospasm. Optimum positioning for the spinal cord patient will be supine. Tidal volume and forced vital capacity are significantly higher in the supine position compared with the sitting position. When sitting, the abdominal contents push up on the diaphragm and place them in a less efficient position 36,37. The use of MI-E in supine may be the position of choice to produce the greatest improvements in the patient’s cough strength. Some patients are managed acutely with tracheostomy. Research has identified that they find suction painful, irritating and uncomfortable. In one study, SCI patients preferred use of MI-E to suction as part of their airway clearance regime when compared to suction alone. They reported that it was less painful, more comfortable and less tiring than suction 20 .
Assisted coughing is also used to duplicate a normal cough. Contraindications to manual-assisted cough or “quad” coughing include unstable spine in traction, internal abdominal complications, chest trauma such as fractured ribs, and a recently placed vena cava filter. MI-E devices alone are therefore indicated in this situation and can be used when there is an unstable spine.
MI-E Frequently Asked Questions Can I use the MI-E in patients with secretion retention and neurological conditions? Yes but, it is important to review what the patient’s problem is. If they have a weak cough MI-E will be of benefit. However, if they have secretions in the peripheral airways IPPB mode maybe the mode of choice. This will enable you to get air behind the secretions towards the central airways to stimulate a spontaneous cough and natural clearance. Can I use the MI-E with patients with learning difficulties? Yes, MI-E can be used in patients with learning difficulties. It is important that they let the device take over and that they do not hold their breath or are asynchronous with the cycle sequence as this will render the treatment mode ineffective and potentially lead to the patient being in distress. Reminding the patient what the device is doing i.e. deep breath in and cough will aid synchronisation. Does the patient need to cough with every exsufflation? No, the patient should let the MI-E device fill up their lungs and then passively deflate the lung, this can be used to enhance mucus towards the central airways. Only when the secretions are in the main airways and the cough reflex has been stimulated then the patient should cough with the machine. How many times a day should MI-E be used? MI-E can be used as many times during a 24-hour period as required to clear your patient’s secretions. However, it is important to remember that prolonged coughing does induce fatigue, so ensure that you allow adequate rest periods. Does MI-E negate the need for suctioning? Using MI-E does not necessarily negate the need for suctioning to clear secretions. Care should be taken when initially using the technique, due to the potential success of the therapy to move secretions.Suction equipment must always be available when treating patients with MI-E. Should MI-E be used if there are no secretions present? If it is considered that there is an area of collapse and/or consolidation on chest x-ray, combined with a patient who has an ineffective cough, MI-E can be indicated. Patients who have a device at home can use it daily to ensure that there are no secretions present. Additionally, the device can be used to provide a stretch to the chest wall and used as a method of IPPB. When should my patient be reviewed with regards to MI-E therapy? This will be dependent on your hospital policy and the severity of your patient. We would suggest that you review your patient within 3 months of initial set up and then on a six to twelve month basis.
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Do patients only ever need one setting? When unwell, some patients may require their settings to be adjusted, in order to maintain effective treatment. This is likely to be an increase of around 5 cmH 2 O. Some MI-E devices have the ability to have more than one profile. This means that you will be able to have a dual prescription and enter setting for when the patient is unwell and when they are well. How do I know my patient is using the therapy? Devices like the Clearway 2 can report usage hours. It also has an internal compliance program that can be downloaded to review adherence. Increase usage can indicate a deterioration in the patient’s condition or alert you that a patient has a respiratory tract infection. How accurate is the CPF reading on the MI-E device? The CPF should be used as a trend and will be different to that recorded value on a peak flow meter. It should be used as a trend for how well a patient is doing. How can I be sure that my patient is getting the settings I have set? Digital settings ensure accurate titration and setting of pressures.
This study showed to addition of oscillations to MI-E did not have an effect on peak cough flow in medically stable subjects with motor neurone disease. However, they did not look at sputum production which has been shown to increase with IPV 43 . Using oscillatory devices has the potential to move a significant amount of secretions into the main airway. It is recommended that appropriate equipment (suction and MI-E) is available to clear these secretions should the need arise 51 . The evidence base for oscillatory therapy is in HFCWO and IPV. Although there is an evidence base for the use of HFCWO and IPV, at the time of writing there is no published evidence to support oscillatory therapy in combination with MI-E to enhance cough strength 50 or decrease respiratory tract infections in motor neurone disease 52 . It is important not to extrapolate the evidence base from HFCWO and IPV to MI-E with oscillatory therapy as the waveforms are different and so is the mechanism of action. Oscillatory therapy is typically used in patients with secretion retention, including the following patient groups: • • • •
Chronic obstructive pulmonary disease (COPD) Cystic fibrosis Bronchiectasis Neuromuscular disease
CONTRAINDICATIONS FOR USE OF THE MI-E WITH OSCILLATIONS
2. M I-E with the addition of Oscillation Therapy Oscillation therapy can be added to the MI-E Mode simply by adding oscillations on to the insufflation, exsufflation pressure or both. The oscillations can be set between 1 and 20 Hz and at an amplitude of 1 to 10 cmH 2 O. MI-E with the addition of oscillation therapy is a proximal ACT unless adapted 1,2 . It can be adapted to a peripheral mobilising technique by decreasing the pressures on the Clearway 2 to allow more cycles so that the aim of oscillatory therapy to move secretions from the peripheral airways to the central airways can be achieved. Then afterwards cleared with MI-E mode. Normal ciliary beat frequency is 10–15 Hz 38 . High frequency oscillations have speculated to cause mini coughs within the airways, the higher expiratory than inspiratory flows favour airway clearance. The reports of the effects of oscillations on mucociliary beat frequency and sputum viscosity are variable. 13 Hz was reported to enhanced mucociliary clearance and 3 Hz to 16 Hz reduced mucus viscosity in dogs 39 . 1 Hz to 8 Hz increased mucus viscosity and the authors concluded that the mechanism of action for high frequency oscillations is not related to changing mucus viscosity 40 . Oscillatory devices can provide ventilatory support and enhance secretion clearance (intrapulmonary percussive ventilation (IPV) 41) and those that can be used in conjunction with ventilator support (high frequency chest wall oscillation (HFCWO)) should be. IPV can assist in resolving persistent atelectasis 42 , can improve secretion clearance in patients prone to secretions with neuromuscular disease 43 . It also has been reported to improve oxygenation 44 and decrease hospital length of stay 45 . HFCWO may assist in secretion clearance to enhance ventilator free time 46 in individuals with neuromuscular disease. HFCWO has been reported to decrease hospitalisations 47-49 , antibiotics requirement 47-49 , improve treatment adherence 49 and produce health care cost savings 48 . A small study concluded that IPV may be more effective at reducing respiratory tract infections when compared to HFCWO 47. Only one study has evaluated the addition of oscillations to MI-E 50 .
There are contraindications to the use of MI-E with oscillations and these are the same as MI-E mode. The considerations are also in the section above.
SUGGESTED GUIDELINE FOR USE: TITRATION & PREPARATION FOR ADULTS If you want the oscillations to enhance cough, follow the initial titration session for the patient with neuromuscular disease follow the suggested algorithm for the initiation of MI-E (Figure 2) and set the oscillations to be on with insufflation or with exsufflation or both. Decide on the amplitude (1–10 cmH 2 O) and the frequency (1–20 Hz). For more information about the practicalities of setting up oscillations with the Clearway 2, visit Education by Breas – Clearway 2 – Using the oscillations. If you are adding oscillations to MI-E to mobilise secretions and for the technique to be a peripheral ACT, consider decreasing the insufflation and exsufflation pressures. Target the pressure to decreasing the work of breathing and add the oscillations with the aim of mobilising secretions from the peripheral airways to the central airways and use MI-E to clear. For patients with chronic lung disease titrate the insufflation and exsufflation pressures to comfort. These should be high enough to decrease the work of breathing but may not need to be so high as to give a maximal insufflation as the aim in this situation is to mobilise secretions rather than to enhancing cough in the NMD patient. Once the pressure settings are optimised go into the menu and turn the oscillations to on. You will be able to set oscillations to be in conjunction with the insufflation, exsufflation or both. You will also need to set the frequency (between 1–20 Hz) and the amplitude of the oscillation between 1–10 cmH 2 O. These are often set to comfort but, you are aiming to feel vibrations within the thorax when you place your hands on the chest wall and therefore may
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need the amplitude to be 10 cmH 2 O. It has been reported that 10–15 Hz enhances mucociliary clearance 53 . Therefore starting between 10 to 15 Hz makes clinical sense. Treatment times with oscillations will need to be longer to enhance secretion movement. A typical treatment time with other oscillatory devices (IPV and HFCWO) is between 10 to 30 minutes. However, caution should be used as the oscillations are in conjunction to positive and negative pressure swings. These pressure swings may consist of high pressures. It is therefore recommended that initial treatments are performed with oxygen saturation monitoring and where possible carbon dioxide monitoring to ensure the patient does not hyperventilate. If you are targeting secretion movement then using lower pressures will allow movement of secretions from the peripheral airways without causing hyperventilation.
OTHER SETTINGS CONSIDERATIONS Oscillations in conjunction to MI-E may be beneficial in patients who experience glottic closure with MI-E. A review of the CPF with and without oscillations maybe used to compare treatment modalities and aid prescription.
POSSIBLE SIDE-EFFECTS OF MI-E WITH OSCILLATIONS These are similar to that of MI-E. Please see side effects of MI-E.
MI-E with the addition of oscillations Frequently Asked Questions Should I use MI-E with oscillations as a first choice with bulbar ALS patients? No, as at present there is no evidence to support this clinically. We therefore recommend you use MI-E without oscillations and consider setting up as per Figure 3. How do I know my treatment is effective? Review the amount of sputum cleared with MI-E and oscillations compared to what they would normally clear with conventional treatment. What is the most effective frequency (Hz) to set? You will need to trial different frequencies and “tune” it to your patient. You may find that you need to use a combination of frequencies to get the best result for your patient.
3. Intermittent positive pressure breathing (IPPB) mode IPPB is a peripheral ACT 1,2 . The aim of IPPB is: 1. To decrease work of breathing 54 by decreasing the mechanical load. 2. Improve distribution of ventilation 55,56 . 3. Improve arterial blood gas tensions with increase tidal volume 55-57. 4. Improve nebulised drug delivery when a T piece is added to the IPPB circuit.
clearance by getting behind secretions and mobilising them towards the central airways. The American Association of Respiratory Care’s clinical practice guidelines for IPPB state the indications include 58 : The need to improve lung expansion in the following situations: • In the presence of significant pulmonary atelectasis when other forms of therapy have been unsuccessful (incentive spirometry, chest physiotherapy, deep breathing exercises, positive airway pressure) • An inability to clear secretions adequately because of pathology that severely limits the ability to ventilate or cough effectively and failure to respond to other modes of treatment. • To provide a chest wall stretch. NIV has been shown to decrease dyspnoea and fatigue during airway clearance in patients with cystic fibrosis 59 . The British thoracic society guidelines for the physiotherapy management of the adult, medical, spontaneously breathing patient, recommendation to consider IPPPB as an alternative to NIV 60 for the mobilisation of secretions from the peripheral airways. IPPB mode can be used in patients with bronchopulmonary disease, including the following patient groups: • • • •
Cystic fibrosis Bronchiectasis Emphysema Post-surgical thoracic and abdominal patients (with no contraindications)
CONTRAINDICATIONS TO IPPB MODE There are contraindications to the use of an IPPB mode. This is a suggested list but may not be exhaustive, always check the Operating Manual of the device you are using. Careful evaluation of the patient will need to occur prior to commencement of treatment: • • • • • • • • • • • • • • •
Tension pneumothorax Uncontrolled asthma Surgical emphysema Vomiting Flail chest Patients with a history or risk of bullous emphysema Patients with a history or are susceptible to pneumothorax or pneumo-mediastinum Patients with tracheoesophageal fistula Recent or existing barotrauma Spinal instability Acute pulmonary oedema Recent oesophageal surgery Increased intracranial pressure Acute lung injury Facial trauma
• Active haemoptysis and frank haemoptysis
CAUTIONS
The physiological result is an improvement in inspiratory flow, optimisation of ventilation through the collateral channels of ventilation. This in turn can aid in secretion
• Unconscious patient who cannot protect their airway and provide feedback. • Recent lung surgery, check with surgical team and see if there is a pressure limit that they would like.
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CONSIDERATIONS BEFORE USING IPPB MODE
• Check the trigger sensitivity. Is the breath in easy to trigger? The trigger should be sensitive enough that the breath is delivered with a small inspiratory effort but, not so sensitive that the device self-triggers. The trigger should also not be set so hard that the patient has to suck hard to get the breath in, as this will cause fatigue. • Next check the speed of the breath in. Is the breath in too fast or too slow? This should be set to patient comfort. Adjust as to patient’s preference, anyone with a fast respiratory rate is likely to need a higher flow. • Next titrate length of the breath in, you are aiming for a long breath in, longer than the patient’s spontaneous breath in. Patients with a faster respiratory rate will need a shorter breath in than those with a slower rate. Adjust the plateau accordingly • Finally, adjust the pressure to provide a deep breath in. This should be set to patient comfort but high enough to give a deep breath in. • Re-evaluate your patient’s settings and re-adjust to patient comfort if required. Ideally you are aiming for a longer, deeper breath in, than the patient is unable to do independently. • Treatment typically consists of cycles of 6–8 breaths with rests in between. The number of cycles will be patient dependent and based on indications for treatment.
• Review the contraindications to using this treatment • Are you competent to use the device and have you received training? For more information about the practicalities of this feature, visit Education by Breas – Clearway 2 – Using the IPPB Mode • Have you connected the IPPB circuit? The dedicated IPPB circuit has an active exhalation valve. This circuit allows the patient to exhale, at (zero) atmospheric pressure, into the atmosphere via the active exhalation valve. This valve helps to prevent air being exhaled back into the breathing circuit. • If you wish to nebulise with treatment have you attached the nebuliser to the circuit? • Where indicated, do you have cardiovascular monitoring available and consider the correct environment for the initiation of MI-E (home, ward, HDU or ICU)? • Is there a suction equipment available, if your patients cough is ineffective?
IPPB Frequently Asked Questions
• Do you have the correct circuit and interface for use for your patient?
Can IPPB be used with all patients? No, IPPB can only be used patients who are able to trigger the device and who use it via a mask or mouthpiece
• Test the device prior to use. • Is oxygen required? You may entrain up to 15 litres of low-pressure oxygen.
Why do I have to change the tubing for IPPB mode?
• Ensure that an anti-bacterial filter is used to protect the patient and machine against any micro-organisms.
This is because you are now no longer delivering negative pressure and therefore CO 2 will not be vented out the back of the device. As IPPB only provides positive pressure, exhalation occurs through the expiratory leak valve to prevent CO 2 retention.
USING IPPB MODE: IPPB mode allows clinicians to set the pressure to be delivered to the patient, the length of the breath in and the slope of the delivery of the breath in along with the trigger sensitivity. We recommended that initial treatments are performed with oxygen saturation monitoring and where possible carbon dioxide monitoring to ensure the patient does not hyperventilate. • Initially trial treatment with a mouthpiece. • If air leaks from the nose, consider the use of nose clips until your patient learns to seal their nose. You want the air to go to the patient’s lungs and not into their cheeks. Encourage them to keep their cheeks taught and not to let the air “puff” their cheeks out. • If you are unsure at what settings to start with consider the following as a suggested starting point: i. Set the flow to 60 L/min (or mid-point) ii. Start the pressure at between 10–15 cmH 2 O iii. Set the plateau at 1 second, if you need a longer breath in then lengthen iv. Unless you are treating a child, in which case you may want to use a more sensitive setting • Explain to the patient that they should trigger the breath in and then let the device to fill their lungs with air. There will be a brief inspiratory hold and then the patient will passively breath out.
Can oxygen be used with IPPB? Yes, oxygen therapy can be used with IPPB. Please use as per the patient’s oxygen prescription. Can I use IPPB on a tracheostomy? No, IPPB mode is for non-invasive use only and therefore should not be used with a tracheostomy or any artificial airway. What interfaces can you use for IPPB? The best interface for IPPB mode is a mouthpiece. However, if your patient cannot seal around the mouthpiece you can use an oronasal mask. Can you set negative pressure in IPPB? In IPPB mode you cannot set a negative pressure. If you wish to have negative pressure you will need to change to MI-E mode. Can you set oscillations in IPPB? It is not possible to set oscillations in IPPB mode. What can I do if my patient complains of dryness? Hydration is key to airway clearance, ensure the patient is well hydrated and encourage sips of water throughout treatment. If this is insufficient you may wish to consider nebulised saline can be given with a T-piece.
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Can drugs be delivered with IPPB? Yes, a T-piece can be added to the circuit in between the exhalation leak valve and mouthpiece, as shown in Figure 6.
A high-efficiency bacterial filter should be placed between patient circuit and device. If you are treating a patient with suspected H1N1 or COVID-19, a filter should be placed at the device end and also at the distal end of the circuit before the interface to double-filter and protect the device. The device should not be taken from dirty to clean areas as defined by local infection control policy. Read more about suggested usage of filters at Education by Breas – Usage of Bacterial Filters for MI-E. How often does the tubing need replacing? Always check the instructions from the manufacturer. As an example, Breas Medical recommends that tubing can be used for up to 7 days.
Figure 6 shows a picture of where to insert the T-piece into the circuit to provide nebulised medication with IPPB mode. Please change the filter after use as they maybe wet from the aerosolization of the medication.
5. Non-invasive ventilation (NIV) Mode Please note that NIV mode as integrated in some MI-E devices is not meant for patients receiving long term NIV. The aim of this mode is to have access to use NIV for a short period of time. This will allow the patient to rest and re-recruit after their airway clearance session if they don’t have long term NIV available to them. Using NIV as a method for ACT has been shown to decrease the work of breathing and maintain oxygen saturation in both adults 59 and children 61 with cystic fibrosis.
General Frequently Asked Questions Can the MI-E be used out and about? Some dives have an internal battery that lasts for around 30 minutes. Please ensure the device is charged sufficiently prior to use outside the house.
Can we use Anti-Bacterial filters that are different? Always check the instructions from the manufacturer. As an example, Breas Medical recommends that you use filters and circuits purchased from us. Considerations for community use and training? It may be advisable within the community to have a Programmed Mode to enable use by only one carer. The settings can be titrated and set and then locked before discharging the patient, ensuring safe and accurate treatment within the community setting. There are competency documents available for carers and clinicians. What information should my patient go home with? The patient and carers should be trained as per your local competency guidelines. The patient should always have a written or photocopied document of their settings. The patient or carer can then check the settings against the record. You may want to give the patient some indication of the changes in settings that they may require for when they are unwell. Where can I get further training about MI-E? Breas Medical runs regular educational days and Webinars. Education by Breas provides up to date information Learn more at Education by Breas – Airway Clearance Archives.
Can the same MI-E be used with different patients? The device will need to be cleaned between patients and each patient should have their own circuit and filter: settings should be checked prior to commencement of treatment.
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