Clinical guideline for Ventilator Hyperinflation as a physiotherapy technique, in adult mechanically ventilated patients

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Roger Hardy
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1 Title of Guideline Contact Name Division and Speciality Clinical guideline for Ventilator Hyperinflation as a physiotherapy technique, in adult mechanically ventilated patients Rebecca Storer (Band 7 Physiotherapist, QMC AICU) Clinical Support Physiotherapy Date of Submission November 2017 Date for Review November 2020 Explicit definition of patient group to which it applies (e.g. inclusion and exclusion criteria, diagnosis) Adult patients who are intubated and mechanically ventilated within a critical care unit at NUH Specifically patients who have reduced lung volumes, viscous secretions and reduced lung compliance Abstract Key Words Statement of the evidence base of the guideline has the guideline been peer reviewed by colleagues? Evidence base: (1-5) 2b at least one other type of well-designed quasi experimental study 4 expert committee reports or opinions and / or clinical experiences of respected authorities 5 recommended best practise based on the clinical experience of the guideline developer Consultation Process Target Audience Exclusion criteria and precautions are included in the guidelines and include: Acute bronchospasm Undrained Pneumothorax Cardiovascular instability Paediatric & neonatal intensive care patients This guideline describes the use of ventilator hyperinflation for the mobilisation of respiratory secretions and recruitment of collapsed/consolidated lung tissue Critical Care, Ventilator Hyperinflation Reduced Lung Volumes Secretion Retention Physiotherapy 2b, 4 and 5 Senior Physiotherapists, Consultant Intensivists, Band 7 Critical Care Nurses Critical Care & Acute Pathway Governance Groups Physiotherapists (band 6 and above) treating respiratory patients in critical care Disclaimer This guideline has been registered with the Nottingham University Hospitals Trust. However, clinical guidelines are guidelines only. The interpretation and application of clinical guidelines will remain the responsibility of the individual clinician. If in any doubt regarding this procedure, contact a senior colleague. Caution is advised when using guidelines after the review date. Please contact the named above with any comments/feedback.

2 Background Ventilator Hyperinflation (VHI) is a technique used by healthcare professionals in critical care. It involves changing ventilator settings to deliver breaths at a higher pressure and/or volume than used at baseline tidal volumes in lung protective ventilation.vhi delivers a larger tidal volume at a slower rate than manual hyperinflation (MHI). The intended effects are to: Optimise alveolar ventilation by recruiting areas of lung tissue atelectasis by utilising principles of collateral ventilation Mobilise pulmonary secretions (Berney and Denehy, 2002 and Savian et al, 2006) VHI can be used as a safe alternative to MHI (see NUH Manual Hyperinflation Guidelines, 2015 available at: It can provide the benefit of being able to monitor the volume and pressure of the breath being delivered to the patient via the ventilator. Positive End Expiratory Pressure (PEEP) is maintained, as there is no disruption of the ventilator circuit. The maintenance of PEEP is important in preventing derecruitment of alveolar units and atelectasis (Hayes, 2011, Berney and Deheny 2002). This is not currently achievable with MHI. Indications: Invasively ventilated patients with Increased viscosity of respiratory secretions that make mobilisation and expectoration / removal difficult Acute chest x-ray changes of lung collapse with or without consolidation Poorly ventilated areas of lung tissue on auscultation (reduced or absent breath sounds) It is an effective alternative to manual hyperinflationmhi via a waters -circuit for patients who are PEEP dependent e.g. patients on >10 cmh 2 0) or patients who need to be more closely monitored via the ventilator (Berney and Denehy 2002, Lemes, Zin, Guimaraes, 2009). Precautions and Complications VHI involves increasing the positive pressure on the ventilator and therefore, the tidal volume (V T ) in the patient s lungs. If used inappropriately VHI carries the risk of complications. Barotrauma and volutrauma are terms used to describe the development of extra alveolar air and fluid due to alveolar distension due to high pressures and high volumes respectively (Dreyfuss and Saumon, 1996). The delivery of high peak airway pressures and or volume increases the risk of haemodynamic instability due to the increase in intrathoracic pressure, which can decrease, stroke volume and cardiac output resulting in hypotension (Singer et al, 1994), (Goodnough, 1985), and cause tachycardia as a result of hypotension (Paratz, 1992 and Stone et al 1991) 1

3 Absolute Contraindications Tension pneumothorax Undrained Pneumothorax Extra alveolar (subcutaneous emphysema) air of unknown origin Precautions Patients have any of the following problems then VHI must be discussed with a Consultant in Critical Care prior to implementation. Recent maxillofacial, neurosurgery or ophthalmic surgery Severe bronchospasm Trache-oesophageal fistula (or suspected) Active haemoptysis Active vomiting Active untreated tuberculosis Radiographic evidence of pulmonary bleb Open chest wounds Bullous lung disease Drained pneumothorax or bubbling chest drain Low/Labile Blood Pressure Bronchial tumour Post thoracic surgery Known obstructive Lung Disease, e.g. Emphysema, (Hyperinflated lungs that may have bullous disease) Cardiac arrhythmias Asthma Intercranial hypertension/ instability Outcome Measures Successful VHI can be defined as one or more of the following: Improvement in auscultation/improved breath sounds Effective clearance of secretions Improved SpO 2 or P a O 2 Reduction in FiO 2 Decreased work of breathing Improved V T post treatment (if on pressure support/ Pressure Control Ventilation) Reduction in peak airway pressure demonstrating increased lung compliance 2

4 Implementation of VHI Action Assess the patients vital signs Note the patients ideal body weight and calculate the target VHI volume range for VHI at ml/kg of this (See Appendix 2 &3) Rationale To ensure they are cardiovascular stable and in order to detect changes in the patient s condition during the procedure Patients will be on a lung protective ventilation strategy with lung volumes targeted at volumes of 4-8 ml/kg of ideal body weight. Limiting the target volume to between ml/kg for VHI will limit the pressure/volume on the lungs in compliance with lung protective ventilation, whilst being an effective treatment (Dennis et al., 2012). The volume range will provide you with a target volume at which treatment is effective. e.g. To calculate treatment volume target : Patient s ideal body weight is 100kg 10ml x 100kg = 1000 mls 15ml x 100kg = 1500mls Therefore effective treatment target VHI volume = mls. Explain the procedure, and obtain consent as able or where appropriate. Where consent is unable to be obtained patient will be treated in best interests. Optimise the patients position for maximal effectiveness of treatment (Lung to be treated is uppermost) Ensure pre-treatment ventilator settings and observations are documented on the observation chart prior to starting VHI. V T /Pinsp PAW alarm, PIP alarm T-insp I:E ratio Minimises the distress to the patient and maximises effectiveness of treatment Confirms the patient is willing to undertake treatment if they have capacity Optimises ventilation to the affected lung and assists with the drainage of secretions (Sholten et al.,1985, Stiller,1990, and Novak, 1987) Pre-treatment ventilator settings need to be documented clearly so that the patient is returned to previous ventilator settings once VHI treatment is completed. 3

5 Ensure flow and pressure waveforms are displayed on the ventilator Change the PAW alarm to 35 cm H 2 O Enables the operator to observe for gas trapping (expiratory flow not returning to baseline) and bronchospasm (Prolonged expiratory flow). If either of these occurs treatment should be terminated Avoids unnecessary alarms during treatment and alerts you to excess pressure on the lungs Please see flowchart of process for pressure control/ support or volume control ventilation. The baseline settings and end settings should be clearly documented in the patient s medical notes, as well as outcomes achieved Additional training All physiotherapy staff using VHI must have completed the mechanical ventilation competency document. A separate VHI competency document and trouble shooting guide will be developed following a trial of the technique. 4

6 Pressure Support/ Pressure Control Mode Increase Pinsp / ASB (if spontaneously breathing) in 2-4 cm H 2 O increments until V T is consistently % greater than original V T OR Reduce the ventilator respiratory rate to 6-8 breaths per min (unless in spontaneous breathing mode) Increase the inspiratory time (Ti) to 3-5 seconds (unless in spontaneous breathing mode) This will ensure a slow inspiration allowing closer monitoring of the patient NB If by 30 cmh 2 O the volume has increased by less than 50% of original V T consider stopping as therapeutic volumes are unlikely to be achieved This allows slow inspiration and a longer inspiratory pause to allow opening of collapsed alveoli. Monitor cardiovascular stability, and expiratory flow waveforms for gas trapping. To ensure safety of the patient during the technique. If unstable return to original settings. Allow 6-8 breaths to be delivered at these settings. Deliver manual techniques alongside this as needed and suction as required To assist secretion clearance and aid reexpansion of collapsed alveoli (MacLean et al. 1989) Complete treatment session with 3 VHI breaths to reinflate any areas of atelectasis caused by suction Return to previous settings by 1) Reducing Pinsp 2) Reducing Ti 3) Return to the frequency Rest the patient for 30 seconds at the previous setting. (unless in spontaneous breathing mode) Repeat the process as needed but without the incremental increase in Pinsp To allow the patient to rest and avoid prolonged exposure to high pressures and volumes To ensure optimal outcome for treatment Once you have completed treatment return the ventilator and it s alarms to previous settings Record the target settings and volumes achieved and outcomes of treatment including auscultation, sputum cleared, V T and SpO 2 post treatment, in patient medical notes and document any adverse effects To ensure patient receives adequate ventilation and safety measures are in place post treatment To ensure treatment is appropriately 5 documented and can easily be replicated

7 Volume Control Mode Increase V T by mls increments until V T is consistently % greater than original V T OR Peak inspiratory pressure of is 35 cmh 2 O Reduce the ventilator respiratory rate to 6-8 breaths per min Increase the inspiratory time (Ti) to between 3-5 seconds This will ensure a slow inspiration allowing closer monitoring of the patient NB If by 30 cm H2O the volume has increased by less than 50% of original vt consider stopping as therapeutic volumes are unlikely to be achieved This allows slow inspiration and a longer inspiratory pause to allow opening of collapsed alveoli. Monitor cardiovascular stability, and expiratory flow waveforms for gas trapping To ensure safety of the patient during the technique. If unstable return to original settings. Allow 6-8 breaths at these settings. Perform manual techniques alongside this as needed and suction as required To assist secretion clearance and aid reexpansion of collapsed alveoli (MacLean et al. 1989) Complete treatment session with 3 VHI breaths to reinflate any areas of atelectasis caused by suction Return to previous settings by 1) Reducing V T Reducing Ti 2) Return to the frequency Rest the patient for 30 seconds at the previous settings To allow the patient to rest and avoid prolonged exposure to high pressures and volumes Repeat the process as needed but without the incremental increase in Pinsp To ensure optimal outcome for treatment Once you have completed treatment return the ventilator and it s alarms to previous settings Record the target settings and volumes achieved and outcomes of treatment including auscultation, sputum cleared, V T and SpO 2 post treatment, in patient notes with any adverse effects To ensure patient receives adequate ventilation and safety measures are in place post treatment 6 To ensure treatment is appropriately documented and can easily be replicated

8 Pressure Support/ Spontaneous breathing mode Increase ASB in 2-4 cm H 2 O increments until V T is consistently % greater than original V T OR Pinsp is 35 cmh 2 O This will ensure a slow inspiration allowing closer monitoring of the patient NB: If by 30 cmh 2 O the volume has increased by less than 50% of original V T consider stopping as therapeutic volumes are unlikely to be achieved Monitor cardiovascular stability, and expiratory flow waveforms for gas trapping To ensure safety of the patient during the technique. If unstable return to original settings. Allow 6-8 breaths to be delivered at these settings. Deliver manual techniques alongside this as needed and suction as required To assist secretion clearance and aid reexpansion of collapsed alveoli (MacLean et al. 1989) Complete treatment session with 3 VHI breaths to reinflate any areas of atelectasis caused by suction Return to previous settings by reducing ASB Rest the patient for 30 seconds at the previous setting To allow the patient to rest and avoid prolonged exposure to high pressures and volumes Repeat the process as needed but without the incremental increase in ASB To ensure optimal outcome for treatment Once you have completed treatment return the ventilator and it s alarms to previous settings To ensure patient receives adequate ventilation and safety measures are in place post treatment Record the target settings and volumes achieved and outcomes of treatment including auscultation, sputum cleared, V T and SpO 2 post treatment, in patient medical notes and document any adverse effects To ensure treatment is appropriately documented and can easily be replicated 7

9 Abbreviations (Appendix 1) VHI MHI PEEP BP SpO 2 P a O 2 FiO 2 V T Pinsp PAW PIP Ti I:E ratio Ventilator Hyperinflation Manual Hyperinflation Positive End Expiratory Pressure Blood Pressure Saturations of oxygen Partial Pressure of Oxygen Fraction of inspired oxygen Tidal volume Peak Inspiratory Pressure Peak Airway Pressure Peak Inspiratory Pressure Inspiratory Time Inspiratory: Expiratory ratio 8

10 Calculating Treatment volumes based on height and ideal weight for Treatment zones Treatment Zones women (Appendix 2) Height cm Ideal Weight kg lower volume (ml) Upper volume (ml)

11 Ideal weight calculated using the equation from the Devine (1974) formula: Ideal Body Weight (men) = kg*( Height(in) - 60 ) 10

12 Calculating Treatment volumes based on height and ideal weight for men (Appendix 3) Height (cm) Ideal weight men(kg) Treatment zones lower volume (ml) Treatment Zones Upper Volume (ml)

13 Ideal weight calculated using the equation from the Devine (1974) formula: Ideal Body Weight (women) = 45.5kg + 2.3kg*( Height(in) - 60 ) 12

14 References Ahmed, F., Shafeeq, A., Moiz, J. and Geelani, M. (2010) comparison of effects of manual versus ventilator hyperinflation on respiratory compliance and arterial blood gases in patients undergoing mitral valve replacement. Heart and Lung: The Journal of Acute and Critical Care 39(5) Berney, S. and Denehy, L. (2002) A comparison of the effects of manual and ventilator hyperinflation on static lung compliance and sputum production in intubated and ventilated intensive care patients. Physiotherapy Research International 7 (2) Dennis, D., Jacob, W. and Budgeon (2012) Ventilator versus manual hyperinflation in clearing sputum in ventilated intensive care patients. Anaesthesia and Intensive Care 40 (1) Devine B.J., (1974) Gentamicin therapy. Drug Intell Clin Pharm 8, Dreyfuss, D. and Saumon, G. (1988) High inflation pressures and pulmonary oedema. Respective effects of high airway pressure, high tidal volume and PEEP. American Respiratory Review of Respiratory Disease Goodnough SK (1985) The effects of oxygen and hyperinflation on arterial oxygen tension after endotracheal suction Heart and Lung Hayes, K., Seller, D., Webb, M., Hodgson, C. and Holland A. (2011).Ventilator hyperinflation: A survey of current physiotherapists practice in Australia and New Zealand. Journal of Physiotherapy, 39 (3) Lemes DA, Zin WA, and Guimarães FS (2009). Hyperinflation using pressure support ventilation improves secretion clearance and respiratory mechanics in ventilated patients with pulmonary infection: a randomised crossover trial, Australian Journal of Physiotherapy 55: MacLean D et al. (1989) Maximum expiratory airflow during chest physiotherapy on ventilated patients before and after the application of an abdominal binder. Intensive Care Medicine 15: Paratz J (1992) Haemodynamic stability of the ventilated intensive care patient: A review. Australian Journal of Physiotherapy Savian, C., Paratz, J and Davies A. (2006) Comparison of the effectiveness of manual and ventilator hyperinflation at different levels of positive end expiratory pressure in artificially ventilated and intubated intensive care patients. Heart and Lung: The Journal of Acute and Critical Care 35 (5) Singer et al (1994) Haemodynamic effects of manual hyperinflation in critically ill mechanically ventilated patients Chest

15 Stone KS et al (1991) Effect f lung hyperinflation and endotracheal suctioning on heart rate and rhythm in patients after coronary artery bypass graft surgery Heart and Lung Sholten, W. et al (1985) Driected manual recruitment of collapsed lung in intubated and non-intubated patients. Annals of Surgery Stiller, K. et al (1990) Actute lobar atelectasis: A comparison of two chest physiotherapy regimes. Chest Novak, R.A. et al (1987) Do periodic hyperinflations improve gas exchange in patients with hypoxaemic respiratory failure? Critical Care Medicine This guideline has been developed in line with those developed by Papworth Hospital NHS Trust and Sherwood Forest Hospitals NHS Foundation Trust. 14

VENTILATORS PURPOSE OBJECTIVES

VENTILATORS PURPOSE OBJECTIVES VENTILATORS PURPOSE To familiarize and acquaint the transfer Paramedic with the skills and knowledge necessary to adequately maintain a ventilator in the interfacility transfer environment. COGNITIVE OBJECTIVES