6
Assists patients effort in initiate an assisted breath. This is to reduce WOB effort
Sensitivity
Usually set at 1:2
- Sigh = 1.5 to 2x the VT (purpose is to spread surfactant)
Inspiratory to expiratory ratio
Adjustable pressure setting to assist inspiration cycle with less patient effort. Increases when ling compliance is low
PIP -- peak inspiratory pressure
Negative pressure a patient is able to generate to initiate spontaneous breath
- Setting: about -25 cm of H2O (normal is > -60 cm H20)
- Measuring respiratory muscle strength ; determine if they are ready to extubate
- Don’t have pressure to expand lungs if they are not working towards 60… chest wall will make lungs collapse
Negative inspiratory force (NIF)
What are the stages of weaning from a volume cycle ventilator?
1. CMV (or A/C)
2. SIMV
3. CPAP
Mode of ventilation:
- For patients providing spontaneous breaths
- Weaning off vent entirely
- Increased spontaneous breathing [trials on IMV mode]
- HOLD PT.. because they are trying to wean and don't want to overexert them and make them go back on the vent
CPAP
Adjustable pressure at which the ventilator delivers the set VT
Pressure limits
Volume of air delivered with each preset breath
- Usually set at 500-700 mL
Tidal volume (VT)
Adds positive pressure to mechanically assist end expiratory phase and prevent the collapse of small airways. Helps increase O2
PEEP -- peak end expiratory pressure
Frequency of breaths delivered by vent
- RR usually set to 12
- Increase RR = increase VE but also increase dead space VD
Respiratory rate
- Has face mask capable of ventilating a non-breathing patient
- Can be attached to an O2 tank to ambulate or transport patient
Ambu bag
Possible alarm causes:
- Air leak somewhere
- Tube disconnection
- Patient effort is low or has stopped breathing (apnea)
- Low battery
Low pressure causes
% of O2 concentrate delivered to patient
- Increased FiO2 - Increased O2 sats
- Ranges from 0.21 (21% = room air) to 1.00 (100% O2)
Fraction of Inspired O2 Concentration (FiO2) ***
What is the normal cm H2O level for NIF (inspiratory muscle strength)?
60
Possible alarm causes:
- Increased WOB
- Breathing outside ventilator parameters
- Obstruction in airway
- Tubing is kinked
- Patient coughs, sneezes, or is suctioned
- Excessive water in tubing
High pressure causes
- Stay calm
- Understand why alarm may go off - low pressure, high pressure, low battery, malfunction
- Never shut off alarms
- Mechanical ventilate the patient with bag-valve device until help arrives
What to do if something goes wrong with ventilator
- Patients feelings can affect ability to wean
- Assure patient that nursing and/or respiratory therapist are always available
- Weaning is more successful if the patient is involved
- Patient perspective is OFTEN different than healthcare team and/or familys
Patients perspective on weaning or extubating
- tachypnea (sustained RR > 35)
- hypotension
- diaphoresis
- hypoxemia a/o hypoxia (less than 90% saturation)
- tachycardia
- bradycardia (CO or arrhythmia issues)
- hypertension
- agitation
- anxiety
S/s of weaning failure or distress ***
Most patients experience extreme uncertainty and stress
- Afraid because they don't know what to expect or what is going on
- Feelings of lack of control and hopelessness
- Frustration at the inability to communicate
- Family visits can increase patient stress
Patients perspective
Room air (no O2) is what percentage of fractionated O2 (FiO2)
21%
At what L of oxygen is the patient likely to be on humidified H2O
4L O2 -- 36% FiO2
- Patients can participate in regular therapeutic activities as long as proper precautions are taken (EX: stable, cleared airway)
- Patients can participate in functional ambulation with assistance of nurse or respiratory therapist can mobilize ventilator (if portable available OR provide % FiO2 through a resuscitation (ambu) bag)
- Therapists need to closely monitor vital signs and body language for signs of distress
PT and OT involvement
- Nasal cannula does not provide hi-flo O2!!!
- Hi-flo delivers up to 100% concentration O2 in mixture of heated and humidified oxygen
- Hi-flo tubing can not have extension tubing added
Considerations for hi-flo O2 (past oxygen tank)
O2 tanks only go up to 10L (maybe 15L)
- Improvements in ABGs (near normal)
- Medical stability from ventilator
- Adequate minute ventilation
- RR between 12 and 16
- Vital capacity > 15 ml/kg of body weight
- NIF between - 20 and - 25 cm H2O
Considerations for weaning from a ventilator
Name the least amount of air support to most amount of support
1. Nasal canula - least
2. Aerosol face mask
3. Face mask with bag - most support and may need to intubate