Mannual hyperinflation Flashcards
techniques to increase lung volume
positioning- too long in supine= basal atelectasis, side lying= reverse atelectasis, reduce risk of pneumonia, promote comfort, protect tissue viability, aids secretion clearance and gas exchange
techniques to increase lung volume- deep breathing and neurophysiological facilitation
deep breathing- can be done if the ventilator allows for some spontaneous effort neurophysiological facilitation (perional stimulation) as it is useful for drowsy patients
mannual hyperinflation
the physio uses a manual bag circuit to deliver extra volume and oxygen to the lungs. it opens atelectasis lung areas, improves oxygenation, facilitate removal of secretions which ultimately improves lung compliance
mimics ACBT
attach to tracheostomy and ventilator
indications for using MHI
removal of excessive or retained secretions that are not easily cleared by suction, to reverse atelectasis- needs pressure of 30-40cmH20, hypoxia to provide 100% oxygen, sometimes to aid auscultation in the absence of any contraindications
equipment for MHI
mannual bag circuit with pressure manometer, an O2 supply
therapeutic effects- MHI
facilitates movement of excess secretions towards central airways, improves oxygenation by optimising alveolar ventilation, improves lung compliance by removing secretions and reversing atelectasis, mimics huff/cough
MHI
consider the use of 0.9% saline (2-10ml), suction as soon as secretions are heard, constantly assess patient through out the procdure, re-assess post treatment
technique of MHI
connect to O2 and start flow (15L/min0, connect the bag to the patient, delver 3-4 slow normal TV breaths, then give 1 mannual hyperinflation breath with or without, quickly releasing the bag mimics huff
slow deep inspiration- to gently increase volume and steadily fill alveoli, inspiratory hold- to allow filling of alveoli with slow time constants, rapid release of bag- to mimic a huff, often used with shaking- accelerate expiratory flow rates
complications of MHI- barotrauma
pressures of 40cmH20 are required to reverse atelectasis. high pressures can rupture the respiratory tract into the surrounding tissue can cause pneumothorax
complications of MHI- depression of respiratory drive and CV instability
depression- can occur when patients are being weaned from the ventilator as you taking over breathing can reduce the patients effort in taking their own breaths
CV instability- increase intrathoracic pressure- decreased VR- decreased CO
Contraindications
severe bronchospasm- increased risk of barotrauma, PEEP>15cm H20 patient will be dependant on this for adequate oxygenation= disconnection causes decreased PEEP, undrained pneumothorax- increased the pneumothorax- CV instability, emphysematous bullae= increased risk of barotrauma
precautions
low/high unstable BP- consider risks vs benefits, cardiac arrhythmias= MHI can irritate the myocardium making them worse, high peak airway pressures and bronchospasm- increased risk of barotrauma, PEEP 10-14cmH20- can’t maintain PEEP so could- collapse and hypoxia, pneumothorax with bubbling chest drain= means gas in escaping, high FiO2 (0.8) or high TV (800mls)- no room for reserve, increased ICP- changes in BP can cause changes in ICP and cerebral perfusion pressure, post lung surgery- reduced lung volumes, weaning patients from ventilators- may depress respiratory drive
alternative ventilator HI
adjusting the ventilator settings to increase TV, simulating a deep breath to recruit collapsed alveoli, dangers and precautions the same as MHI- except for high PEEP and high FiO2,
