Management of volume loss Flashcards
What does reduced lung volume mean
Decreased lung volume refers in this case to a ↓ amount of aerated lung
What does reduced lung volume mean to PTs
- Physiotherapy can only be used to directly manage some causes of reduced lung volume
- Only collapse can be directly treated by physiotherapeutic techniques
- When lung volume is not amenable to physiotherapy we can optimise V/Q matching
State causes of reduced lung volume
Atelectasis/collapse • Alveoli • Segment • Lobe • Total lung Others • Consolidation • Thoracic cage restriction, lung tissue restrictive disease will reduce lung volume • Pleural effusion, pneumothorax & abdominal distension compress the lung
Is consolidation treatable by PTs?
Consolidation is not directly treatable Aim to prevent worsening by • Mobilisation • Hydration • Positioning • Education of breathing techniques
What is the significance with atelectasis
• Reduces amount of functioning lung
• Reduces surface area of ventilated lung
• Reduced surface area for gas exchange
○ V/Q mismatch
○ Decreased SaO2 (Low saturations, poor ABG’s)
• Decreased lung compliance & increases airway resistance (balloon analogy)
• Increased WOB
State causes of atelectasis
• Immobility/prolonged bed rest • Poor positioning • Pain • Shallow breathing pattern (narcotics or CNS) • Airway occlusion ○ Mucus plug ○ Tumour in airway ○ Foreign object ○ Airway compression ○ High O2 - absorption atelectasis All above can occur in surgical & medical patient
Benefits of increasing lung volume
• Increase the amount of functioning lung
• Increase surface area
○ Improve V/Q match
○ Increase SaO2 (>95% Sats, PO2 10-14Kpa)
• Increase lung compliance and decrease airway resistance
• Decrease WOB
• Decrease the risk of sputum retention and infection
Treatment options to increase lung volume
- Positioning
- Mobilisation - controlled mobilisation is the therapeutic and prescriptive application of low-intensity exercise in the management of cardiopulmonary dysfunction in acutely ill patients
- Breathing Exercises (TEEs) - always to relaxed breathing exercises first
- Incentive Spirometry (IS)
- IPPB/bird
- NIPPY Clearways/cough assists
- Neurophysiological facilitation
- CPAP
How does IS work
Works to increase ventilation by utilising collateral channels
Indications for IS
Children, post-op pts at high risk of atelectasis, unable to follow instructions of more active techniques
Warnings when using IS
Ensure pain is controlled, wounds post-op (supported cough), cognition/post op drowsiness
How to measure effectiveness of positive pressure techniques
Increase in volume, duration; reassess Ausc, CXR, O2 sats within an hour
Give instructions for IS
Sit upright, hold IS at eye level, tight seal around mouthpiece
Then breathe in through mouth and move the piston as up as you can whilst keeping the indicator between the two arrows
Hold for 3-5 secs and try 10 breaths/hour
Cough as needed but always finish with a breath in to avoid collapse from DC
How does Intermittent Positive Pressure Breathing (IPPB) work
AKA Non-Invasive Positive Pressure Breathing (NIPPB) or the BIRD
How it works:
Works by pressure supported inspiration, Intermittent positive pressure applied during inspiration
Patient triggers inspiration by taking a breath and then a sustained positive pressure is applied to the patients airway to a set pressure level
Pushes patient into IRV
Greater volumes → improved gas exchange, decreased WOB
Followed by passive expiration
Indications IPPB
• Atelectasis / Volume loss when patient is
○ Tired
○ Drowsy - particularly kidney failure pts due to reduced metabolism, GA takes longer to be flushed
○ Weak
○ Neurologically impaired - MS, GBS, MND, muscle dystrophy
• i.e. unable to fully participate in more active treatments
• May also be used to aid secretion clearance
Contraindications/precautions for all positive pressure breathing techniques
- Undrained pneumothorax - exacerbate
- Surgical Emphysema of unknown cause - approval of consultant
- Bullae - rupture
- Bronchospasm or Acute asthma - side effect - pre-neb then reassess
- Recent Oesophageal or lung surgery - approval of consultant for adequate healing
- Hypoxic drive patients - O2 drives RR as an adaptation due to CO2 retention (COPD) and as such 100% O2 can slow their RR; normally CO2 levels drives RR
- Active TB or H1N1 (swine flu + any flu) - contagion risk as equipment
- Nausea - exacerbate, may vomit
- Gastric distention without NG tube - exacerbate
- Flail chest - pneumothorax risk, get approval of consultant on what is higher risk
- Broncho pleural fistula - hole
- Proximal airway tumours - no issue with increasing lung volume but passive expiration may lead to trapped air behind tumour
- Haemoptysis - exacerbate
- Raised intra cranial pressure/acute head injury - positive pressure not selective - increase in intrathoracic pressure in turn increases intracranial pressure
- CVS instability (acute MI, CCF arrhythmias, BP issues) - positive pressure not selective - increase in intrathoracic pressure in turn increases strain on heart
- Facial #’s or burns (mask only) - issue with tight seal around mouth and noses if there is skin integrity and/or pain issues
- ENT problems - approval of consultants
Recommended starting settings
10-10-10
Sensitivity or starting effort: Set low to allow patient to breath in easily without increasing work of breathing; effort required to trigger breath
Inspiratory pressure: 8-15 cmH20 dependent on patient presentation
Increasing gradually to approx. 20-25cmH2O (not >30cmH2O)
Inspiratory flow rate (AKA RR): Commence at mid-range
Increase if patient is very breathless
Increasing time (reducing RR) so that the patient has a sustained inspiratory period
Aim: Slow deep breaths
All other controls should be switched off
Give instructions for IPPB use
• Place 5mls of normal saline into the nebuliser chamber of the circuit
• Attach the circuit to the IBBP machine
• Choose the most appropriate delivery interface i.e. mouthpiece, face mask, ETT or tracheostomy connector
• Using appropriate interface instruct patient to:
○ Inhale slowly and deeply, allowing the machine to fill their lungs with air
○ Pause briefly at end of inhalation then exhale - utilise collateral channels
• Ensure good lip seal or use nose clip for mouthpiece
• Ensure no “puffing” cheeks if using mouthpiece or facemask
• Reduce sensitivity if patient is finding it difficult to trigger & increase sensitivity if machine is auto triggering
• Adjust inspiratory pressure for adequate volume observed by chest expansion (desired pressure is at least 20 Kpa as this is required for adequate cough)
• Adjust inspiratory flow rate to match patients rate of breathing and allow good inspiratory breath time and expansion
• 6-8 breaths with rests in between and 5 cycles; Ideally done hourly but clinically 3X/day and teaching pts ACBTs in between
What is NIPPY Clearway and Cough Assist
Is a mechanical insufflation-exsufflation (MI-E)
Insufflation = positive inspiratory pressure
Exsufflation = negative pressure applied at the mouth for secretion removal
How to use NIPPY Clearway & Cough Assist
Can be used with different interfaces – mouthpiece, face mask or tracheostomy connector
Can set the pressures and the time taken in both the I and E phase
Can be delivered manually, patient triggered or time set
Indications for NIPPY Clearway & Cough Assist
Can be used to give deeper breaths by increasing inspiratory pressure
For volume loss just set the Insufflation to a desired pressure
Due to its many modes the machine can be used to increase volumes, remove secretions and as a Non-invasive positive pressure ventilator (NIPPV) - for CO2 retention
What is Continuous Positive Airway Pressure (CPAP)
As the name suggests it is positive pressure applied throughout the whole respiratory cycle i.e. inspiration and expiration
How does CPAP work
- Keeps the airway pressure higher than atmospheric throughout the whole respiratory cycle
- It delivers a constant flow of gas which exceeds the patients demands
- This will increase FRC above CV thus recruiting collapsed alveoli and maintaining higher lung volumes - maintaining splinting of airways
Indications for CPAP
Last step prior to mechanical ventilation or weaning off
NOT for secretions - end up in mask
How is CPAP delivered
- Hood
- Full mask
- Mask
- Nasal
What is neurophysiological facilitation
- Use of proprioceptive stimuli producing a reflex which increases the depth of inspiration
- Intercostal stretch
- Rib springing
- More commonly used in chronic conditions causing reduced lung volume
