Ventilation201 Flashcards
(29 cards)
Respiratory Failure Type 1
Hypoxemia
-Sp02 <90%
-Pa02 <60mmHg
-PaC02 normal or below normal
-Most common
Respiratory Failure Type 2
Hypoxemia + Hypercapnia
-PaC02 >45mmHg
-Sp02 <90%, Pa02 <60mmHg
Hypercapnic Respiratory Failure Examples
Medulla dysfunction
Tox
Neuromuscular disease (Guillain-Barre, Myasthenia Graves, Polio, Spinal Injuries)
Chest wall/Pleural Diseases
Upper Airway Obstructions
Peripheral Airway Disorder (asthma, COPD)
Respiratory Failure Management
- Reverse & prevent hypoxemia
- Control PaC02 & acidosis
- Treat underlying disease
Calculate Complaince
Cstat= Vt
——————–
Plateau-PEEP
-Normal 50-7ml/cmH20
-Compliance describes the elastic property of the respiratory system
Calculate Resistance
RAW= PIP-plateau
——————- x60
VI
C02 Management Equation
RR = known EtC02 x known RR
————————————
desired EtC02
Factors effecting rate of diffusion
Pressure gradient
Solubility coefficient
Membrane permeability
Membrane thickness
Surface area
Factors that increase PIP
Increased inspiratory flow
Increased set Vt
Increased airway resistance
Decreased lung compliance
Increased PEEP
Kinged, obstructed or misplaced ETT
Patient ‘fighting’ the ventilator
Coughing
If PIP >30
- Dope
- Ventilator Dysynchrony
- Inspiratory hold
What is PIP
Measure of resistive + elastic forces
Measured at the mouth
Reflects the amount of PRESSURE required to overcome airway resistance
What is an Inspiratory Hold
Assists in understanding why PIPs are elevated.
May be the result of an increase in airway resistance or a decrease in lung compliance.
What is an Inspiratory Hold
Assists in understanding why PIPs are elevated.
May be the result of an increase in airway resistance or a decrease in lung compliance.
Permissive Hypercapnea Indications
Patients with ARDS managed with low tidal volume.
Patients ventilated for exacerbations of asthma or chronic lung disease who require low tidal volume and/or a low respiratory rate to minimize intrinsic PEEP.
Permissive Hypercapnea Contraindications
-Cerebral Disease
-CAD, Heart Failure, Cardiac Arrhythmias, Pulmonary HTN, Right Ventricular Disfunction (increases sympathomimetic output which would be poorly tolerated by patients who have cardiac disease)
-Hypovolemia (can induce systemic vasodilation)
Permissive Hypercapnea Adverse Effects
Increased HR, arrhythmias, BP
Exacerbation of right heart dysfunction
Increased ICP
Worsening of hypoxemia & lung injury
VALI/VILI
Ventilator Associated/Induced Lung Injury - cellular level lung injury that occurs as a result of PPV. Presents like ARDS
Prevention of VALI
-Limit plateau aureate pressure to under 30cmH20
-Limit tidal volumes to 6ml/kg
-Aim for lower oxygen levels, tolerate Sp02 88-90%
Use high PEEP (15) to prevent cyclic atelectasis
-Use neuromuscular function blockers
-Consider prone ventilation
‘Baby Lung’
The fraction of lung that still maintains normal inflation with near normal mechanical characteristics. The baby lung is not anatomical but a functional entity which changes dimensions and location with prone position and PEEP application.
Ventilating ARDS Patient
-Pressure Control
-Lung Protective Ventilation (low tidal volumes)
-Use a higher PEEP with a lower plateau pressure
-Accept a level of permissive hypercapnia.
-I:E 1:1, manipulating does not help patient
-Neuromuscular blockade
-Inhaled pulmonary vasodilators
Ventilating Asthma Patient
-Use volume-control
-Largest Tube Possible
-Sp02 90-92%
-10-12 breaths/minute or less
-Long expiratory time (1:3/1:4)
-Heavy sedation & neuromuscular blockade
-Minimal PEEP
-Keep pplat below 25
Asthma Ventilated Patient Therapies
Humidified O2
Nebulized beta-agonists & anticholinergic drugs
Hydrocortisone or prednisone
Magnesium
Mechanical ventilation can _____ ICP and _____ CPP.
Increase ICP
Decrease CPP
Increases in PaCO2 and decreases in PaO2 do what to ICP?
Increase it
