Manual Hyperinflation: Difference between revisions

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<div class="editorbox"> '''Original Editor '''- [[User:User Name|Sarah Popperwell]] '''Top Contributors''' - {{Special:Contributors/{{FULLPAGENAME}}}}</div>
== Introduction ==


=== '''Introduction''' ===
Manual hyperinflation also known as manual ventilation or ‘bagging’, is a technique used by respiratory physiotherapists in the management of ventilated patients or patients self-ventilating through a tracheostomy. Manual hyperinflation is used to increase lung volumes and aid secretion clearance when used in conjunction with [[suctioning]]<ref name=":0">Volpe MS, Naves JM, Ribeiro GG, Ruas G, Tucci MR. Effects of manual hyperinflation, clinical practice versus expert recommendation, on displacement of mucus simulant: A laboratory study. PloS one. 2018 Feb 12;13(2):e0191787.
[[File:1-s2.0-S0031940612000557-gr2.jpg|thumb|Manual Resuscitator Bag used for Manual Hyperinflation or "bagging"]]
</ref>. Manual hyperinflation involves the use of a manual resuscitator bag (MRB) connected to oxygen to provide a slow, deep inspiratory breath followed by an inspiratory pause of 1-2 seconds, and a rapid release of the resuscitation bag <ref>Lemes DA, Zin WA, Guimarães FS. 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. 2009 Jan 1;55(4):249-54.
</ref>.


Manual hyperinflation also known as manual ventilation or ‘bagging’, is a technique used by respiratory physiotherapists in the management of ventilated patients or patients self-ventilating through a tracheostomy. Manual hyperinflation is used to increase lung volumes and aid secretion clearance when used in conjunction with [[suctioning]]<ref name=":0">Volpe, M. S., Naves, J. M., Ribeiro, G. G., Ruas, G., &amp;amp; Tucci, M. R. (2018). Effects of manual
== Technique<ref>youtube.com https://www.youtube.com/watch?v=209txhJW3iM&feature=emb_title</ref> ==
hyperinflation, clinical practice versus expert recommendation, on displacement of mucus
It's a technique that uses a manual resuscitation bag to deliver tidal volumes (Vt) 100-150 percent larger than baseline Vt and a peak airway pressure of no more than 40 cmH2O while delivering a slow inspiratory flow, followed by an inspiratory hold, and a fast expiratory flow that generates a whirlwind peak expiratory flow.<ref>Cruz RV, Andrade FD, Menezes PD, Gonçalves BO, Almeida RD, Santos AR. [https://www.scielo.br/j/fm/a/JjggQKrNBVhs8krbtZXkyPh/?lang=en Manual hyperinflation and the role of physical therapy in intensive care and emergency units.] Fisioterapia em Movimento. 2017;30:241-8.</ref>{{#ev:youtube|209txhJW3iM}}
simulant: A laboratory study. PLoS ONE, 13(2), 1–11.
 
</ref>. Manual hyperinflation involves the use of a manual resuscitator bag (MRB) connected to oxygen to provide a slow, deep inspiratory breath followed by an inspiratory pause of 1-2 seconds, and a rapid release of the resuscitation bag <ref>Lemes, D. A., Zin, W. A., &amp;amp; Guimarães, F. S. (2009). Hyperinflation using pressure support ventilation
== Mechanism of action ==
improves secretion clearance and respiratory mechanics in ventilated patients with pulmonary
infection: A randomised crossover trial. Australian Journal of Physiotherapy, 55(4), 249–254.
</ref>'''.'''
=== '''Mechanism of action''' ===


==== '''To increase volume''' ====
==== '''To increase volume''' ====
Manual hyperinflation is used to manage [[atelectasis]][[Atelectasis.|.]] The mechanism it is thought to work is by increasing alveolar recruitment. The squeezing of the resuscitation bag increases the baseline tidal volumes during inspiration by approximately 1L <ref>Frank, U., Frank, K., &amp;amp; Zimmermann, H. (2015). Effects of respiratory therapy (bagging) on
Manual hyperinflation is used to manage [[Atelectasis|atelectasis]] The mechanism it is thought to work is by increasing alveolar recruitment. The squeezing of the resuscitation bag increases the baseline tidal volumes during inspiration by approximately 1L <ref>Frank U, Frank K, Zimmermann H. Effects of respiratory therapy (bagging) on respiratory function, swallowing frequency and vigilance in tracheotomized patients in early neurorehabilitation. Pneumologie. 2015 May 12;10:0034-1392359.
respiratory function, swallowing frequency and vigilance in tracheotomized patients in early
</ref>. This increase in tidal volume plus inspiratory hold allows time for alveoli and collateral airways to open, thereby increasing lung compliance and reducing atelectasis <ref name=":1">Bennett BG, Thomas P, Ntoumenopoulos G. Effect of inspiratory time and lung compliance on flow bias generated during manual hyperinflation: A bench study. Respiratory care. 2015 Oct 1;60(10):1449-58.
neurorehabilitation. Pneumologie, 69(07), 394-399.
</ref>. This increase in tidal volume plus inspiratory hold allows time for alveoli and collateral airways to open, thereby increasing lung compliance and reducing atelectasis <ref name=":1">Bennett, B. G., Thomas, P., &amp;amp; Ntoumenopoulos, G. (2015). Effect of Inspiratory Time and Lung
Compliance on Flow Bias Generated During Manual Hyperinflation: A Bench Study. Respiratory
Care, 60(10), 1449–1458.
</ref>.
</ref>.


==== '''For secretion clearance''' ====
==== '''For secretion clearance''' ====
MH not only increases the tidal volume but the quick release of the resuscitation bag increases the elastic recoil of the lung and therefore increases the expiratory flow rate. The expiratory flow rate is necessary to mobilise secretions.   
Manual hyperinflation not only increases the tidal volume but the quick release of the resuscitation bag increases the elastic recoil of the lung and therefore increases the expiratory flow rate. The expiratory flow rate is necessary to mobilise secretions.   


The mechanism for how this works can be explained by the engineering concept of two-phase gas-liquid flow; moving gas in a tube transfers momentum to the stationary liquid, and occurs when the expiratory flow rate is greater than inspiratory flow rate<ref name=":2">Maxwell, L., &amp;amp; Ellis, E. (1998). Secretion clearance by manual hyperinflation: Possible mechanisms.
The mechanism for how this works can be explained by the engineering concept of two-phase gas-liquid flow; moving gas in a tube transfers momentum to the stationary liquid, and occurs when the expiratory flow rate is greater than inspiratory flow rate<ref name=":2">Maxwell L, Ellis E. Secretion clearance by manual hyperinflation: possible mechanisms. Physiotherapy Theory and Practice. 1998 Jan 1;14(4):189-97.
Physiotherapy Theory and Practice, 14(4), 189–197.
</ref><ref name=":1" /><ref name=":0" />.  A normal cough generates very high expiratory airflow, which creates mist flow of the secretions to enable them to be expelled from the airways. However, the expiratory flow generated with Manual Hyperinflation is still much slower than a normal cough, and so moves secretions using annular flow instead. Manual Hyperinflation may therefore prevent mucus plugging and associated lobar collapse <ref name=":3">Paulus F, Binnekade JM, Vroom MB, Schultz MJ. Benefits and risks of manual hyperinflation in intubated and mechanically ventilated intensive care unit patients: a systematic review. Critical Care. 2012 Aug 1;16(4):R145.</ref>. The use of a pressure manometer is recommended to ensure this expiratory flow bias <ref name=":0" />.  
</ref><ref name=":1" /><ref name=":0" />.  A normal cough generates very high expiratory airflow, which creates mist flow of the secretions to enable them to be expelled from the airways. However, the expiratory flow generated with Manual Hyperinflation is still much slower than a normal cough, and so moves secretions using annular flow instead. Manual Hyperinflation may therefore prevent mucus plugging and associated lobar collapse <ref name=":3">Paulus,F., Binnekade, J.M., Vroom, M.B. & Schultz MJ (2012) Benefits and risks of manual hyperinflation in intubated and mechanically ventilated intensive care unit a systematic review. Critical Care, 16 (4), R145</ref>. The use of a pressure manometer is recommended to ensure this expiratory flow bias <ref name=":0" />.  


Once the secretions have been mobilised, [[suctioning]] is often used to expectorate them from the patient.   
Once the secretions have been mobilised, [[suctioning]] is often used to expectorate them from the patient.   


=== '''Indications''' <ref name=":4">Hodgson C et al. An investigation of the early effects of manual lung hyperinflation in critically ill patients. Anaesthesia and Intensive Care 2000; 28: 255-261</ref><ref name=":3" /> ===
== Indications  ==
** '''Clearance of retained secretions and mucus plugging'''
* Clearance of retained secretions and mucus plugging<ref name=":1" /><ref name=":2" /><ref name=":4">Hodgson CL, Denehy L, Ntoumenopoulos G, Santamaria J, Carroll S. An investigation of the early effects of manual lung hyperinflation in critically ill patients. Anaesthesia and intensive care. 2000 Jun;28(3):255-61.</ref>
** '''Recruitment of areas of [[atelectasis]] or collapse'''
* Recruitment of areas of [[atelectasis]] or collapse<ref name=":3" />
** '''To improve ventilation/perfusion (V/Q) matching'''
* To improve ventilation/perfusion (V/Q) matching<ref name=":5" />
** '''To improve lung compliance'''
* To improve lung compliance<ref name=":3" />
** '''To improve regional lung ventilation'''
* To improve regional lung ventilation<ref name=":3" /><ref name=":5" />
** '''To improve oxygenation'''
* To improve oxygenation<ref name=":4" />


=== '''Absolute Contraindications''' <ref name=":3" /><ref name=":4" /><ref>St George's University Hospital. MANUAL HYPERINFLATION (MHI) (2016) Guidelines for Manual Hyperinflation for Adult Patients, clinical guide https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&ved=2ahUKEwib9-7oq_frAhWwQxUIHcrpAXUQFjACegQIBRAB&url=http%3A%2F%2Fwww.gicu.sgul.ac.uk%2Fresources-for-current-staff%2Frespiratory-physiotherapy%2FGuidelines%2520MHI%2520v1.2%2520June%25202016.docx%2Fat_download%2Ffile&usg=AOvVaw1AMzDTstWa6GGdBUTSNxsv</ref> ===
== Absolute Contraindications <ref name=":3" /><ref name=":4" /><ref name=":5">St George's University Hospital. MANUAL HYPERINFLATION (MHI) Guidelines for Manual Hyperinflation for Adult Patients, clinical guide. 2016 Accessed at https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&ved=2ahUKEwib9-7oq_frAhWwQxUIHcrpAXUQFjACegQIBRAB&url=http%3A%2F%2Fwww.gicu.sgul.ac.uk%2Fresources-for-current-staff%2Frespiratory-physiotherapy%2FGuidelines%2520MHI%2520v1.2%2520June%25202016.docx%2Fat_download%2Ffile&usg=AOvVaw1AMzDTstWa6GGdBUTSNxsv</ref> ==
**   '''Undrained [[pneumothorax]]'''
* Undrained [[pneumothorax]]<ref name=":6">Paratz J, Lipman J, McAuliffe M. Effect of manual hyperinflation on hemodynamics, gas exchange, and respiratory mechanics in ventilated patients. Journal of Intensive Care Medicine. 2002 Nov;17(6):317-24.</ref><ref name=":5" />
**  '''Severe bronchospasm'''
* Severe bronchospasm<ref name=":3" />
**   '''Head injury with ICP > 25mmHg'''
* Head injury with ICP > 25mmHg<ref name=":5" /><ref name=":6" />
**   '''Severe arterial hypotension'''
* Severe arterial hypotension<ref name=":6" />
**  '''High peak end inspiratory pressure (PEEP) ventilation and PEEP dependency'''
* High peak end inspiratory pressure (PEEP) ventilation and PEEP dependency<ref name=":6" />
**   '''Nitric Oxide ventilation'''
* Nitric Oxide ventilation<ref name=":5" /><ref name=":6" />
**   '''High Frequency Oscillation Ventilation'''
* High Frequency Oscillation Ventilation<ref name=":5" />


=== '''Relative Contraindications'''<ref name=":0" /><ref name=":2" /><ref name=":3" /><ref name=":4" /> ===
== Relative Contraindications ==
Note: These relative contraindications are for ‘therapeutic’ manual hyperinflation.
''Note: These relative contraindications are for ‘therapeutic’ manual hyperinflation.''<ref name=":0" /><ref name=":2" /><ref name=":3" /><ref name=":4" /><ref name=":5" /><ref name=":6" />
{| class="wikitable"
{| class="wikitable"
|'''·          Cardiovascular  (CVS) instability/arrhythmias'''
|'''Cardiovascular  (CVS) instability/arrhythmias'''
|Compromised  venous return- further increases effort required to maintain adequate tissue  perfusion
|Compromised  venous return- further increases effort required to maintain adequate tissue  perfusion
|-
|-
|'''·          Acute  Respiratory Distress Syndrome (ARDS)'''
|'''Acute  Respiratory Distress Syndrome (ARDS)'''
|Increases  risk of pneumothorax/barotrauma
|Increases  risk of pneumothorax/barotrauma


NB! This does not preclude the  use of the MRB in resuscitation situations in this patient group
NB! This does not preclude the  use of the MRB in resuscitation situations in this patient group
|-
|-
|'''·          Severe  exacerbation Chronic Obstructive Pulmonary Disease ([[COPD (Chronic Obstructive Pulmonary Disease)|COPD]]) / Bronchospasm'''
|'''Severe  exacerbation Chronic Obstructive Pulmonary Disease ([[COPD (Chronic Obstructive Pulmonary Disease)|COPD]]) / Bronchospasm'''
|Increased  airway pressure will increase airway irritation and inflammatory response
|Increased  airway pressure will increase airway irritation and inflammatory response
|-
|-
|'''·          High  PEEP (> 10cmH2O)'''
|'''High  PEEP (> 10cmH2O)'''
|The  break in the circuit will cause loss of PEEP and can de-recruit lung
|The  break in the circuit will cause loss of PEEP and can de-recruit lung
|-
|-
|'''·          Raised  intracranial pressure (ICP)'''
|'''Raised  intracranial pressure (ICP)'''
|Increased intrathoracic pressure reduces mean  arterial pressure which can compromise cerebral perfusion pressure
|Increased intrathoracic pressure reduces mean  arterial pressure which can compromise cerebral perfusion pressure
|-
|-
|'''·          Proximal  Tumor/obstruction'''
|'''Proximal  Tumor/obstruction'''
|Risk of  dislodging or causing trauma
|Risk of  dislodging or causing trauma
|-
|-
|'''·          Emphysematous  Bullae'''
|'''Emphysematous  Bullae'''
|Increases  risk of pneumothorax
|Increases  risk of pneumothorax
|-
|-
|'''·          Recent  lung  surgery e.g. lobectomy/pneumonectomy'''
|'''Recent  lung  surgery e.g. lobectomy/pneumonectomy'''
|High  airway pressure may cause trauma/pneumothorax. Check with surgeons regarding  stump pressure.
|High  airway pressure may cause trauma/pneumothorax. Check with surgeons regarding  stump pressure.
|-
|-
|'''·          Hypotension  (Systolic <80)'''
|'''Hypotension  (Systolic <80)'''
|Increased positive pressure in thoracic cavity  compromises venous return – reduces cardiac output
|Increased positive pressure in thoracic cavity  compromises venous return – reduces cardiac output
|-
|-
|'''·          Patients  dependent on hypoxic drive'''  
|'''Patients  dependent on hypoxic drive'''  
|High  levels of O<sub>2</sub> being delivered/increased P<sub>a</sub>O<sub>2</sub>  levels may reduce drive to breathe
|High  levels of O<sub>2</sub> being delivered/increased P<sub>a</sub>O<sub>2</sub>  levels may reduce drive to breathe
|-
|-
|'''·          Acute  Head Injury'''
|'''Acute  Head Injury'''
|As for raised ICP
|As for raised ICP
|-
|-
|'''·          Unexplained  Haemoptysis'''
|'''Unexplained  Haemoptysis'''
|May be  indicative of acute trauma to the lung parenchyma  
|May be  indicative of acute trauma to the lung parenchyma  
|-
|-
|'''·          High  respiratory rate'''
|'''High  respiratory rate'''
|Difficult  to co-ordinate the technique
|Difficult  to co-ordinate the technique
|-
|-
|'''·          Subcutaneous  [[Emphysema]]'''
|'''Subcutaneous  [[Emphysema]]'''
|May indicate  the presence of a pneumothorax
|May indicate  the presence of a pneumothorax
|-
|-
|'''·          ECMO patients'''
|'''ECMO patients'''
|Should be discussed with on-call ECMO consultant
|Should be discussed with on-call ECMO consultant
|}
|}


=== '''Technique''' ===
 
{{#ev:youtube|209txhJW3iM}}
 
== Related Pages ==
[[Physiotherapists Role in ICU]]
 
[[Category:Cardiopulmonary]]
[[Category:Cardiopulmonary]]
[[Category:Respiratory Disease - Interventions]]  
[[Category:Respiratory Disease - Interventions]]  

Latest revision as of 12:45, 3 November 2021

Introduction[edit | edit source]

Manual hyperinflation also known as manual ventilation or ‘bagging’, is a technique used by respiratory physiotherapists in the management of ventilated patients or patients self-ventilating through a tracheostomy. Manual hyperinflation is used to increase lung volumes and aid secretion clearance when used in conjunction with suctioning[1]. Manual hyperinflation involves the use of a manual resuscitator bag (MRB) connected to oxygen to provide a slow, deep inspiratory breath followed by an inspiratory pause of 1-2 seconds, and a rapid release of the resuscitation bag [2].

Technique[3][edit | edit source]

It's a technique that uses a manual resuscitation bag to deliver tidal volumes (Vt) 100-150 percent larger than baseline Vt and a peak airway pressure of no more than 40 cmH2O while delivering a slow inspiratory flow, followed by an inspiratory hold, and a fast expiratory flow that generates a whirlwind peak expiratory flow.[4]

Mechanism of action[edit | edit source]

To increase volume[edit | edit source]

Manual hyperinflation is used to manage atelectasis The mechanism it is thought to work is by increasing alveolar recruitment. The squeezing of the resuscitation bag increases the baseline tidal volumes during inspiration by approximately 1L [5]. This increase in tidal volume plus inspiratory hold allows time for alveoli and collateral airways to open, thereby increasing lung compliance and reducing atelectasis [6].

For secretion clearance[edit | edit source]

Manual hyperinflation not only increases the tidal volume but the quick release of the resuscitation bag increases the elastic recoil of the lung and therefore increases the expiratory flow rate. The expiratory flow rate is necessary to mobilise secretions.

The mechanism for how this works can be explained by the engineering concept of two-phase gas-liquid flow; moving gas in a tube transfers momentum to the stationary liquid, and occurs when the expiratory flow rate is greater than inspiratory flow rate[7][6][1]. A normal cough generates very high expiratory airflow, which creates mist flow of the secretions to enable them to be expelled from the airways. However, the expiratory flow generated with Manual Hyperinflation is still much slower than a normal cough, and so moves secretions using annular flow instead. Manual Hyperinflation may therefore prevent mucus plugging and associated lobar collapse [8]. The use of a pressure manometer is recommended to ensure this expiratory flow bias [1].

Once the secretions have been mobilised, suctioning is often used to expectorate them from the patient.

Indications[edit | edit source]

  • Clearance of retained secretions and mucus plugging[6][7][9]
  • Recruitment of areas of atelectasis or collapse[8]
  • To improve ventilation/perfusion (V/Q) matching[10]
  • To improve lung compliance[8]
  • To improve regional lung ventilation[8][10]
  • To improve oxygenation[9]

Absolute Contraindications [8][9][10][edit | edit source]

  • Undrained pneumothorax[11][10]
  • Severe bronchospasm[8]
  • Head injury with ICP > 25mmHg[10][11]
  • Severe arterial hypotension[11]
  • High peak end inspiratory pressure (PEEP) ventilation and PEEP dependency[11]
  • Nitric Oxide ventilation[10][11]
  • High Frequency Oscillation Ventilation[10]

Relative Contraindications[edit | edit source]

Note: These relative contraindications are for ‘therapeutic’ manual hyperinflation.[1][7][8][9][10][11]

Cardiovascular (CVS) instability/arrhythmias Compromised venous return- further increases effort required to maintain adequate tissue perfusion
Acute Respiratory Distress Syndrome (ARDS) Increases risk of pneumothorax/barotrauma

NB! This does not preclude the use of the MRB in resuscitation situations in this patient group

Severe exacerbation Chronic Obstructive Pulmonary Disease (COPD) / Bronchospasm Increased airway pressure will increase airway irritation and inflammatory response
High PEEP (> 10cmH2O) The break in the circuit will cause loss of PEEP and can de-recruit lung
Raised intracranial pressure (ICP) Increased intrathoracic pressure reduces mean arterial pressure which can compromise cerebral perfusion pressure
Proximal Tumor/obstruction Risk of dislodging or causing trauma
Emphysematous Bullae Increases risk of pneumothorax
Recent lung  surgery e.g. lobectomy/pneumonectomy High airway pressure may cause trauma/pneumothorax. Check with surgeons regarding stump pressure.
Hypotension (Systolic <80) Increased positive pressure in thoracic cavity compromises venous return – reduces cardiac output
Patients dependent on hypoxic drive High levels of O2 being delivered/increased PaO2 levels may reduce drive to breathe
Acute Head Injury As for raised ICP
Unexplained Haemoptysis May be indicative of acute trauma to the lung parenchyma
High respiratory rate Difficult to co-ordinate the technique
Subcutaneous Emphysema May indicate the presence of a pneumothorax
ECMO patients Should be discussed with on-call ECMO consultant


Related Pages[edit | edit source]

Physiotherapists Role in ICU

References[edit | edit source]

  1. 1.0 1.1 1.2 1.3 Volpe MS, Naves JM, Ribeiro GG, Ruas G, Tucci MR. Effects of manual hyperinflation, clinical practice versus expert recommendation, on displacement of mucus simulant: A laboratory study. PloS one. 2018 Feb 12;13(2):e0191787.
  2. Lemes DA, Zin WA, Guimarães FS. 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. 2009 Jan 1;55(4):249-54.
  3. youtube.com https://www.youtube.com/watch?v=209txhJW3iM&feature=emb_title
  4. Cruz RV, Andrade FD, Menezes PD, Gonçalves BO, Almeida RD, Santos AR. Manual hyperinflation and the role of physical therapy in intensive care and emergency units. Fisioterapia em Movimento. 2017;30:241-8.
  5. Frank U, Frank K, Zimmermann H. Effects of respiratory therapy (bagging) on respiratory function, swallowing frequency and vigilance in tracheotomized patients in early neurorehabilitation. Pneumologie. 2015 May 12;10:0034-1392359.
  6. 6.0 6.1 6.2 Bennett BG, Thomas P, Ntoumenopoulos G. Effect of inspiratory time and lung compliance on flow bias generated during manual hyperinflation: A bench study. Respiratory care. 2015 Oct 1;60(10):1449-58.
  7. 7.0 7.1 7.2 Maxwell L, Ellis E. Secretion clearance by manual hyperinflation: possible mechanisms. Physiotherapy Theory and Practice. 1998 Jan 1;14(4):189-97.
  8. 8.0 8.1 8.2 8.3 8.4 8.5 8.6 Paulus F, Binnekade JM, Vroom MB, Schultz MJ. Benefits and risks of manual hyperinflation in intubated and mechanically ventilated intensive care unit patients: a systematic review. Critical Care. 2012 Aug 1;16(4):R145.
  9. 9.0 9.1 9.2 9.3 Hodgson CL, Denehy L, Ntoumenopoulos G, Santamaria J, Carroll S. An investigation of the early effects of manual lung hyperinflation in critically ill patients. Anaesthesia and intensive care. 2000 Jun;28(3):255-61.
  10. 10.0 10.1 10.2 10.3 10.4 10.5 10.6 10.7 St George's University Hospital. MANUAL HYPERINFLATION (MHI) Guidelines for Manual Hyperinflation for Adult Patients, clinical guide. 2016 Accessed at https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&ved=2ahUKEwib9-7oq_frAhWwQxUIHcrpAXUQFjACegQIBRAB&url=http%3A%2F%2Fwww.gicu.sgul.ac.uk%2Fresources-for-current-staff%2Frespiratory-physiotherapy%2FGuidelines%2520MHI%2520v1.2%2520June%25202016.docx%2Fat_download%2Ffile&usg=AOvVaw1AMzDTstWa6GGdBUTSNxsv
  11. 11.0 11.1 11.2 11.3 11.4 11.5 Paratz J, Lipman J, McAuliffe M. Effect of manual hyperinflation on hemodynamics, gas exchange, and respiratory mechanics in ventilated patients. Journal of Intensive Care Medicine. 2002 Nov;17(6):317-24.