Manual Hyperinflation: Difference between revisions

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=== '''Introduction''' ===
[[File:1-s2.0-S0031940612000557-gr2.jpg|thumb|Manual Resuscitator Bag used for Manual Hyperinflation or "bagging"]]
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
hyperinflation, clinical practice versus expert recommendation, on displacement of mucus
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
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''' ====
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
respiratory function, swallowing frequency and vigilance in tracheotomized patients in early
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 atelactasis <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>.
==== '''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. 
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>Maxwell, L., &amp;amp; Ellis, E. (1998). Secretion clearance by manual hyperinflation: Possible mechanisms.
Physiotherapy Theory and Practice, 14(4), 189–197.
</ref><ref name=":1" /><ref name=":0" />.  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 clear them from the patient.
=== '''Absolute Contraindications''' ===
**   '''Undrained [[pneumothorax]]'''
**  '''Severe bronchospasm'''
**   '''Head injury with ICP > 25mmHg'''
**   '''Severe arterial hypotension'''
**  '''High peak end inspiratory pressure (PEEP) ventilation and PEEP dependency'''
**   '''Nitric Oxide ventilation'''
**   '''High Frequency Oscillation Ventilation'''
=== '''Relative Contraindications''' ===
Note: These relative contraindications are for ‘therapeutic’ mh
{| class="wikitable"
|'''·          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 O<sub>2</sub> being delivered/increased P<sub>a</sub>O<sub>2</sub>  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
|}
=== Technique ===
https://www.youtube.com/watch?v=209txhJW3iM
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  [[Category:Cardiopulmonary]]
  [[Category:Cardiopulmonary]]
[[Category:Respiratory Disease - Interventions]] [[Category:Respiratory Disease - Interventions]]
[[Category:Respiratory Disease - Interventions]]  
[[Category:Respiratory Disease - Interventions]]

Revision as of 10:15, 20 September 2020

Introduction[edit | edit source]

Manual Resuscitator Bag used for Manual Hyperinflation or "bagging"

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].

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 [3]. This increase in tidal volume plus inspiratory hold allows time for alveoli and collateral airways to open, thereby increasing lung compliance and reducing atelactasis [4].

For secretion clearance[edit | edit source]

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.

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[5][4][1]. 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 clear them from the patient.

Absolute Contraindications[edit | edit source]

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

Relative Contraindications[edit | edit source]

Note: These relative contraindications are for ‘therapeutic’ mh

·         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

Technique[edit | edit source]

https://www.youtube.com/watch?v=209txhJW3iM

Be the first to edit this page and have your name permanently included as the original editor, see the editing pages tutorial for help.

  1. 1.0 1.1 1.2 Volpe, M. S., Naves, J. M., Ribeiro, G. G., Ruas, G., &amp; Tucci, M. R. (2018). Effects of manual hyperinflation, clinical practice versus expert recommendation, on displacement of mucus simulant: A laboratory study. PLoS ONE, 13(2), 1–11.
  2. Lemes, D. A., Zin, W. A., &amp; Guimarães, F. S. (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(4), 249–254.
  3. Frank, U., Frank, K., &amp; Zimmermann, H. (2015). Effects of respiratory therapy (bagging) on respiratory function, swallowing frequency and vigilance in tracheotomized patients in early neurorehabilitation. Pneumologie, 69(07), 394-399.
  4. 4.0 4.1 Bennett, B. G., Thomas, P., &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.
  5. Maxwell, L., &amp; Ellis, E. (1998). Secretion clearance by manual hyperinflation: Possible mechanisms. Physiotherapy Theory and Practice, 14(4), 189–197.