non-invasive ventilation
DESCRIPTION
Non-invasive Ventilation. Dr Liam Doherty, Consultant Respiratory Physician, Bon Secours, Cork. P ositive A irway P ressure. CPAP = continuous positive airway pressure BiPAP = Bilevel positive airway pressure = Inspiratory pressure (IPAP) and expiratory pressure (EPAP). - PowerPoint PPT PresentationTRANSCRIPT
Non-invasive VentilationDr Liam Doherty,Consultant Respiratory Physician,Bon Secours, Cork
Positive Airway Pressure
CPAP = continuous positive airway pressure
BiPAP = Bilevel positive airway pressure = Inspiratory pressure (IPAP)
and expiratory pressure (EPAP)
Why?
Invasive ventilation
SedatedCan’t speakCan’t eatHigh infection riskIncreased bleeding riskBarotraumaLimited ICU beds
Non-invasive ventilation
Not sedatedCan speakCan eatLow infection riskAvailable on well-supervised medical wards
How does it work?
In summaryStents airwayRecruitment of alveoliDecreases right to left intrapulmonary shuntingDecreases work of breathingOvercomes PEEPiLowers left ventricular transmural pressure reducing afterload and increasing cardiac output
Who gets NIV?
Acute Type 2 Respiratory failure
COPD, pH <7.35 despite maximum Rx on controlled O2Cardiogenic pulmonary oedema with hypoxia. Decompensated obstructive sleep apnoea. Chest wall trauma who remain hypoxic. (CPAP)Diffuse pneumonia who remain hypoxic despite maximum Rx (CPAP)Weaning from invasive ventilation.
Who can’t have NIV?Recent facial or upper airway/upper GI surgery, Facial burns or trauma, Fixed obstruction of the upper airway, Vomiting.Inability to protect the airway, Copious respiratory secretionsLife threatening hypoxaemia, Severe co-morbidity, Confusion/agitation, Bowel obstruction.
Which ventilator
Types of NIVNegative pressure ventilation e.g. “iron-lung”, tank, shell, cuirass, rocking bed,
pneumo-beltPositive pressure ventilation Pressure limited (CPAP, Bilevel PAP) Volume limited
N.B. Diaphragm-pacing, glosso-pharyngeal breathing,
cough insufflator-exsufflator
Which interface
How do you commence NIV?
Monitoring progressOximetryRespiratory ratePatient comfortPCO2
Patient-ventilator synchronisationGive breaks for drinks/foodKeep on for as long as possible (2 days+)
When things go wrong!
Is ventilation inadequate?
Observe chest expansionIncrease target pressure (or IPAP) or volumeConsider increasing inspiratory timeConsider increasing respiratory rate (to increase minute ventilation)Consider a different mode of ventilation/ventilator, if available
Is the patient synchronising with the ventilator?
Observe patientAdjust rate and/or IE ratio (with assist/control)Check inspiratory trigger (if adjustable)Check expiratory trigger (if adjustable)Consider increasing EPAP (with bi-level pressure support in COPD)
Downside to NIV
Horrendous to wearCan’t talkCan’t eat/drinkCan’t sleepAgitation, claustrophobiaPoor synchronyDelays intubation
Final messagesGive appropriate oxygen!Non-invasive ventilators just blow airTry to synchronise ventilator to patient i.e. ventilator should support normal ventilationWhen in doubt use CPAPNIV doesn’t work for everyone (30% failure rate)Never forget need for intubation!