Rationale for use

Mechanical insufflation:exsufflation (MI:E)

For patients to successfully clear secretions, they need to be able to cough; there are 3 phases to an effective cough. The inspiratory phase consists of a larger than tidal volume breath (approx. 80% of vital capacity). This is followed by glottic closure enabling a forced expiratory phase with a greater flow than the inspiratory phase. This propels secretions more proximally enabling them to be cleared via the upper airway (Laghi, Maddipati, Schnell, Langbein, & Tobin, 2017). The use of MI:E can improve both the inspiratory and expiratory phase by increasing vital capacity during the inspiratory phase and increasing expiratory flow, resulting in greater secretion clearance. Evidence supports the use of MI:E in patients with neuromuscular disease, spinal cord injury and chronic secretion burden (Chatwin, et al., 2018). There is emerging evidence for its use in critical care and it is used widely in this population across the NHS (Nunes, et al., 2019).

Peak cough flow (PCF) can be assessed and used to guide the use of MI:E (Chatwin, et al., 2018).

• Normal PCF: 360-1200l/min

• Borderline PCF: <270l/min – likely to need some form of cough augmentation - consider using MI:E

• Inadequate PCF: <160l/min – MI:E should be used prophylactically

Intermittent positive pressure breathing (IPPB)

IPPB alone can help to support airway clearance in patients with an adequate cough but with secretions that remain difficult to clear by enhancing the inspiratory phase. This is achieved by increasing the vital capacity and thus utilising collateral channels of ventilation to move secretions more proximally (Denehy & Berney, 2001). IPPB can also be beneficial for use in patients with reduced inspiratory capacity to provide larger volume breaths to minimise the risk of chest infections, for example in patients that are limited by reduced inspiratory muscle strength or pain.

Contraindications and precautions for the use of IPPB/MI:E

Contraindications:

• Undrained pneumothorax

• Bullous emphysema

• Facial trauma/fractures (when using IPPB/MI:E via a face mask)

• Chest/lung trauma

• Recent upper GI surgery

• Frank haemoptysis

• Tracheo-oesophageal fistula/ Broncho-pleural fistula

• Proximal airways tumour

• Recent barotrauma

• Intracranial pressure >20mmHg

Precautions:

• Acute head injury

• Cardiovascular instability

• Spinal instability

• Abdominal distension/ileus/nausea

• Patients with chronic airways disease, at risk of dynamic airway collapse (exsufflation only)

• Draining pneumothorax (need to ensure drain is patent at beginning & end of treatment)

• Recent thoracic surgery

Equipment

Available Devices

Across Frimley Health, available devices for using MI:E and IPPB include the Phillips CoughAssist E70 and NIPPY Clearway 2. Both machines are able to provide positive and negative pressures making them appropriate to use for both MI:E/IPPB. The set-up of the machines differs, with slightly different settings available, however both are able to provide manual and automatic modes. Medical device competency forms (available on local physiotherapy Teams channel/SharePoint) should be completed and signed by all Physiotherapists competent to use the devices.

Consumables

There is one circuit available for use with both devices. It comes assembled as pictured below. The circuit should be changed every 7 days or unless visibly soiled. Date the packet of the circuit with the date it was opened. Don’t connect the circuit together in a loop, when storing in between use – this contaminates the ‘clean’ end of the filter with the ‘dirty’ patient end.

Oxygen can be entrained using an oxygen entrainer and green oxygen tubing.

• Place the O2 connector at the patient end of the circuit. See image below.

• Connect the green tubing to the oxygen flow meter or cylinder at the desired flow.

There are several interfaces that can be used depending on the patient, see image below. For self-ventilating patients, there is an anaesthetic face mask or mouthpiece. If using a mouthpiece, an optional nose clip can be used if desired.

For ventilated patients, the circuit connects directly onto the corrugated section of the closed-circuit suction (CCS), see image below. In some circumstances, a catheter mouth may also be used for patients with excessive secretions.

Set-up of machine

Nippy Clearway 2

• Ensure the machine in plugged in – note there is no internal battery, therefore the machine must be plugged in to function.

• Connect the circuit to the port on the right-hand side of the machine, the filter end closest to the machine.

• Turn on the machine by pressing and holding the On-Off button on the bottom left on the front of the device.

• Therapy settings are accessible through the touch screen controls on the main screen.

Phillips Coughassist E70

• Ensure the machine in plugged in – note there is no internal battery, on most of the devices in the trust, therefore these machines must be plugged in to function.

• Connect the circuit to the port on the right-hand side of the machine, the filter end closest to the machine.

• Turn on the machine by pressing the On-Off button on the right of the screen.

• Therapy settings are accessible by navigating with the buttons at the bottom of the screen.

Mode selection

There is a selection of modes on each machine. The table below provides an outline of each mode. The differences in trigger and flow for the two machines are also detailed here.

MI:E setting selection

All setting selection should be based on clinical reasoning. Consider the patient’s pathology, past medical history, contraindications and precautions, and current support when selecting MI:E settings. The table below provides a guide for suggested starting pressures for various patient groups.

Please note: In order to achieve an expiratory flow bias, the exsufflation pressure should be more negative than the insufflation pressure and the and the exsufflation time should be shorter than the insufflation time (Volpe, Naves, Ribiero, Ruas, & Amato, 2018). In intubated patients, the exsufflation time and/or pause time will need to be sufficient to allow time for the simultaneous closed-circuit suction.

IPPB setting selection

Phillips E70

• Select advanced auto mode/manual mode.

• Turn coughtrak on if using advanced auto.

• Set insufflation, flow, and Ti as above.

• Set exsufflation to 0cmH2O.

Nippy Clearway2

• Select IPPB mode.

• Set the inspiratory pressure by selecting ’Max INS’.

• Set the inspiratory hold time by selecting ‘Plateau’.

• Adjust the flow depending on the patient’s presentation and comfort by selecting the ‘flow’ button. A suggested flow would be 60-100L/min.

• The trigger can be set to patient trigger 1(easy) to 10 (hard) or manually triggered using the switch on the front of the machine.

MI:E/IPPB via Facemask/mouthpiece

If using a mask, ensure it is the correct size for the patient. The mask should be an anaesthetic facemask. If using a mouthpiece, an optional nose clip may also be used.

• Connect the mask/mouthpiece to the patient end of the circuit.

• If using manual mode, two people are likely to be required, one to hold the mask and one to control the machine.

• Firmly hold the mask against the patients face. If able, the patient can hold it.

MI:E via endo-tracheal tube (ETT)

Critically ill patients receiving mechanical ventilation via an ETT often experience impaired airway clearance. An ineffective cough can also be associated with respiratory muscle weakness, prolonged inactivity and altered mucociliary clearance. The effectiveness of cough for sputum clearance may also be impaired or absent due to the use of sedatives, paralysing agents and the prevention of glottic closure due to the presence of the ETT. This can lead to secretion retention, increased risk of pneumonia and weaning failure. Recent evidence demonstrates that using MI:E via ETT at pressures >40cmH₂0 facilitates extubation of both neuromuscular and non-neuromuscular patients and should therefore be considered as part of routine chest physiotherapy (Swingwood, et al., 2022).

Caution should be taken if the patient is on a PEEP >10 or on APRV and discussed with the intensive care consultant prior to use.

Pre-procedure

• Perform full A-E assessment and document findings.

• Ensure haemodynamic stability

• The ventilator should be optimised to ensure adequate tidal volume (V_T), alveolar P_ACO₂ and minimal inspired oxygen. If the patient is acidotic and hypercapnic, ventilation should be optimised before attempting MI:E.

• Perform routine airway clearance techniques, ensuring no secretions in the upper airway e.g. CCS.

• Document ETT insertion length at teeth and ensure cuff is adequately inflated – check cuff pressure.

Procedure

• It is preferable to perform MI:E with two clinicians in the intubated and ventilated population. This will often be one physiotherapist and one nurse.

• Position the patient to optimise secretion mobilisation.

• Set up the MI:E device as described above.

• Entrain oxygen into the MI:E circuit if the patient is on FiO2 >0.3 or deemed at risk of desaturation. Perform a manual disconnect on the ventilator. Connect the MI:E circuit to the corrugated section of tubing close to the patient, leaving the closed-suction in situ. See picture below.

• Deliver the MI:E treatment cycle. See mode and setting selection section above for suggested mode and settings.

• Perform CCS during exsufflation, you may need a nurse to assist, if no one is available to assist, perform CCS after exsufflation.

• Re-recruit the patient using insufflation breaths (these can be between 1-2 secs in duration) until ready to perform the next MI:E cycle

• If needing to complete multiple cycles (approx. >5), consider giving the patient a rest on the ventilator before continuing treatment.

• Monitor vital signs, volumes, and PCF throughout the procedure and manage accordingly. Treatment should be discontinued in the event of haemodynamic instability.

• When connecting the patient back to the ventilator, check they are ventilating before a reassessment including V_T, PIP, auscultation, palpation, and vital signs. Ensure ETT insertion length is the same as pre-procedure.

MI:E/IPPB via tracheostomy

MI:E has been shown to be safe for use with patients with tracheostomies (Sancho, et al., 2021).

The procedure for patients with a tracheostomy is the same as for patients with an ETT. For patients who are self-ventilating, the CCS can still be used and connected onto the tracheostomy for treatment, or a catheter mount can be used followed by an open suction. This is usually only done in patients who are likely to require MI:E long term.

Please note, in order for the MI:E/IPPB to be most effective, the cuff should be inflated to a pressure of 25-30mmHg. If you have inflated the cuff for your MI-E/IPPB treatment please return the patient to cuff down at the end of treatment & document this clearly in your notes.

There are instances where ‘laryngeal weaning’ is taking place – this is where additional airflow/stimulation of the patient’s upper airway is indicated to improve their physiological cough/swallow. In these instances, the specialist physiotherapist involved in this wean may advise for the MI:E to be delivered either via the upper airway using a face mask or via the tracheostomy but with the cuff deflated. If you are unsure, please liaise directly with the specialist physiotherapist leading the wean program.

The exterior of the machines should be wiped after every use with detergent wipes or chlorclean wipes for infectious patients.

Both devices should be serviced yearly. This is arranged through the EME department on the relevant site. The respiratory seniors manage this on their respective sites.

There are filters on both machines that should be changed at regular intervals:

• Phillips E70: One grey filter at the rear of the machine which should be changed 6 monthly

• Nippy Clearway2: One white filter and one grey filter at the back of the machine. The white should be changed monthly and the grey changed annually.

MI:E treatments should be documented in the notes on Epic. There are smartphrases available to help with the documentation of MI:E treatments.

These are ‘.E70’ and ‘.Nippy’.

Rationale

There may be situations where it is appropriate for an MI:E device to be used by non-physiotherapy staff. This would always be when a patient has been seen and had an MI:E device set up for them by a specialist respiratory physiotherapist.

Staff members that this may be applicable to include:

• Nursing staff

• Carers E.g. home care agency training

Patients who would have a device set up for them would usually be patients with a longer-term MI:E need for example SCI or NMD.

Competencies

The competency document (available on local physiotherapy Teams channel/SharePoint) must be signed off by a respiratory specialist physiotherapist. It is then down to the individual member of staff to maintain their competence with using the device. If they need refresher training, they should contact the ICU or respiratory team lead.

Chatwin, M., Toussaint, M., Gonçalves, M. R., Sheers, N., Mellies, U., Gonzales-Bermejo, J., . . . Morrow, B. M. (2018). Airway clearance techniques in neuromuscular disorders: a state of the art review. Respiratory Medicine, 136, 98-110. Retrieved from https://doi.org/10.1016/j.rmed.2018.01.012

Denehy, L., & Berney, S. (2001). The use of positive pressure devices by physiotherapists. European Respiratory Journal, 17, 821-829. Retrieved from https://doi.org/10.1183/09031936.01.17408210

Laghi, F., Maddipati, V., Schnell, T., Langbein, W., & Tobin, M. (2017). Determinants of cough effectiveness in patients with respiratory muscle weakness. Respiratory Physiology & Neurobiology, 240, 17-25. Retrieved from https://doi.org/10.1016/j.resp.2017.02.005

Nunes, L., Rizzetti, D., Neves, D., Vieira, F., Kutchak, F., Wiggers, G., & Pacanha, F. (2019). Mechanical insufflation/exsufflation improves respiratory mechanics in critical care: Randomized crossover trial. Respiratory Physiology & Neurobiology, 266, 115-120. Retrieved from https://doi.org/10.1016/j.resp.2019.05.008

Sancho, J., Bures, E., Ferrer, S., Lahosa, C., Signes-Costa, J., & Servera Emilio. (2021). Mechanical insufflation-exsufflation with oscillations in amyotrophic lateral sclerosis with home ventilation via tracheostomy. Respiratory Care, 66(3), 378-383. Retrieved from https://doi.org/10.4187/respcare.08145

Swingwood, E., Stilma, W., Tume, L., Cramp, F., Voss, S., Bewley, J., . . . Rose, L. (2022). The use of mechanical insufflation-exsufflation in invasively ventilated critically ill adults. Respiratory Care, 67(8), 1043-1057. Retrieved from https://doi.org/10.4187/respcare.09704

Volpe, M., Naves, J., Ribiero, G., Ruas, G., & Amato, M. (2018). Airway clearance with an optimized mechanical insufflation-exsufflation maneuver. Respiratory Care, 63, 1214-1222. Retrieved from https://doi.org/10.4187/respcare.05965

This guideline has been registered with the Trust. However, clinical guidelines are guidelines only. The interpretation and application of clinical guidelines will remain the responsibility of the individual clinician. If in doubt, contact a senior colleague or expert. Caution is advised when using guidelines after the review date.

This guideline is for use in Frimley Health NHS Foundation Trust hospitals only. Any use outside this location will not be supported by the Trust and will be at the risk of the individual using it.

Version History

Related Documents

Coughassist – Competency for Nursing Staff

Coughassist – E70

Coughassist – Clearway2