Invasive Ventilation Flashcards
Indications
impending/existing acute respiratory failure
cardiac arrest
reduced respiratory drive to breathe
airway protection
upper airway obstruction/trauma
reduce work of heart in congestive heart failure
significant rise in metabolic demand
Advantages
full ventilatory support for conscious and unconscious patients drives larger pressure gradients can titrate FiO2 easier to individualise stabilises thorax in trauma patients
Disadvantages
requires ICU admission - 1:1 supervision potential airway trauma requires sedation/paralysis nosocomial infection increased WOB decreased ability to communicate patient discomfort VQ mismatch
VQ mismatch invasive ventilation
positive pressure forces ventilation of non-dependent lung areas - follows the path of least resistance
Perfusion still gravity dependent - results in mismatch between ventilation and perfusion
Trigger
how the ventilator knows when to start a breath
Mandatory - ventilator initiates all breaths according to a set RR
Spontaneous - patient initiates and terminates all breaths, controls RR
- machine provides support
Combination - ventilator at set rate
- patient can initiate breaths in between
- provides back up with patient goes for too long without a breath
Control
defines the primary mechanism of control of inspiration
- usually pressure or volume controlled
Volume - aim to deliver a minimum tidal volume
Pressure - don’t excess set pressure limit
Cycling
what makes the ventilator stop inspiration
- volume, time, flow or pressure controlled
Different types of Invasive Ventilation
CMV - Controlled Mandatory Ventilation
- machine does all work, requires full sedation
SIMV - synchronous intermittent mandatory ventilation
- may or may not have pressure support also
ASB - Assisted Spontaneous Breathing
- no set tidal volume or mandatory breaths
- patient triggers each breath, can be awake, no guaranteed minute ventilation
APRV - Airway pressure release ventilation
- ventilator cycles between two different CPAP levels
- allows for spontaneous breathing at high lung volumes
- patient is able to initiate a spontaneous breath at etiher level
- two levels are required to allow gas to move in and out of the lung
- waste gas is eliminated as pressure is released to a lower level
Role of Physio
identify any asynchrony
mode of ventilation has implications for physio management
- can disconnect from ventilation for treatment
- work around ventilation to optimise rehab
Artificial Airways - indications physio
unconscious patient who is unable to protect own airway
patient who doesn’t have the strength or coordination to clear their airway
significant amounts of secretions that are very dififcult to clear
Facilitates suctioning as part of treatment targeting airway clearance
OPA VS NPA
Oropharyngeal Airway - good for emergency situations when need to quickly insert the airway, not alert patients, don’t have jaw trauma, no gag reflex
Nasopharyngeal Airway - good when going to be in place for longer periods of time, no BOS fracture, nasal trauma or bleeding nose, better for alert patients
Do not go into the trachea
Contrainidcations OPA
oral cavity or jaw trauma
oral cavity obstructionn
patient awake and alert
loose teeth
Contraindications NPA
nasal or facial fractures CSF leak BOS fracture coagulopathy torn dura bleeding nose hypotension laryngospasm
Indications for Intubation
Intubation - provision of an artifical airway into the trachea i
Facilitates tracheobronchial suctioning and also mechanical ventilation
airway obstruction inadequate oxygenation increased WOB airway protection required GA
Intubation Procedure
via an endotracheal tube or tracheostomy tube
goes into the trachea to the level of the carina
provides a definitive airway
facilitates mechanical ventilation or suctioning
usually has a cuff which is inflated
no communication between upper and lower airways
