Chpter One, Clinical Application for Mechanical Ventilation David W. Chang
Air flow obstruction in the airways primarily affected by length siiize and patency of the airway, endotracheal tube, and ventilator circuit
Airway Resistance (RAW)
Formula for RAW
Normal Airway Resistance value
0.6 and 2.4 cm H20/L/sec at a flow rate of 30 L/min
Biggest contributor to increased airway resistance
internal diameter of the ET tube
_________ may result if the patient is unable to overcome the airway resistance by increasing the work of breathing.
As a result of _____________, patients with chronic airway obstruction may develop highly compliant lung parenchyma and use a breathing pattern that is deeper but slower.
chronic air trapping
Patients with __________ breath more shallowly but faster since air flow resistance is not the primary disturbance in these patients.
restrictive lung disease
Occurs when the patients minute ventilation cannot keep up with CO2 production.
Failure of the lungs to eliminate carbon dioxide. Without supplemental oxygen, it leads to hypoxemia.
Failure of the heart and lungs to provide adequate oxygenation for metabolic needs
The degree of lung expansion (volume change) per unit of pressure change(work of breathing)
high work of breathing
reduced functional residual capacity
restrictive lund disorder
Low minute ventilation
Increase RR to Compensate
Gas exchange process impaired
destruction of lung tissue
chronic air trapping
enlargement of terminal and respiratory bronchioles
conditions that increase patient's functional residual capacity
obstructive lung defect
air flow obstruction
poor gas exchange
reflects the elastic resistance of the lung and chest wall
measured when airflow is present
airway resistance is a critical factor in the measurement of compliance
reflects nonelastic airway resistance as well as the elastic properties of the lung and chest wall.
In conditions where the airflow resistance is increased (such as with bronchospasm)
PIP is increased Dynamic Compliance is decreased while the Plateau pressure and static compliance (these two are directly related) stays unchanged