EQUIPMENT-Resp monitors & equipment Flashcards
Define resistance
The force that acts opposite to the relative motion of an object (or flow)
Define pulmonary compliance
The ability of the lungs to stretch and expand.
The change in volume fore a given change in pressure
What are 2 types of pulmonary compliance
- Static compliance
2. Dynamic compliance
What does static compliance assess
Assesses the pressure required to keep the lung inflated inflated to a given volume when there is no air movement
Compliance when there is no airflow to keep lungs open
What does dynamic compliance assess
Assesses the pressure required to inflate the lung to a given volume when there’s airflow
Compliance of the lung/chest wall during air movement
What 2 factors impact dynamic compliance
- Airway resistance
2. Tendency of the lungs/chest to collapse
What is PIP
Peak inspiratory pressure
Maximum pressure in the patients airway during inspiration
What is plateau pressure
The pressure in the small airways and alveoli after the target Vt is achieved
What do alterations in PIP and plateau pressure indicate
Pressures in resistance or compliance
How is increased resistance manifested with PIP and plateau pressure
Examples of increased resistance
PIP = increased PP = normal
Ex: kinked tubing, bronchospasm
How is decreased pulmonary compliance displayed with PIP and plateau pressure
Examples
PIP = increased
Plateau pressure = increased
Ex: Endobronchial intubation, pulmonary edema
What are 5 factors that influence pulmonary compliance
- Muscle tone
- Degree of lung inflation
- Alveolar surface tension
- Amount of interstitial lung water
- Pulmonary fibrosis
What is the equation for dynamic compliance
Dynamic compliance = tidal volume/(PIP - PEEP)
What factor of pulmonary mechanics does plateau pressure reflect
Elastic recoil of the lungs and thorax during inspiratory pause
At what plateau pressure does barotrauma risk increase
P>35 cmH2O
What are 4 complications of elevated plateau pressure
- Ventilator-associated lung injury
- PTX
- Pneumomediastinum
- SQ emphysema
What measures can be taken to decrease the risk of barotrauma r/t increased plateau pressure
- Reduce Vt
- Reduce inspiratory flow (I:E ratio)
- PEEP
- Adequate sedation
Statis compliance equation
Static compliance = Tidal volume/(plateau pressure - PEEP)
What is the normal range for static compliance in adults and children
Adults = 35 - 100 mL/cmH2O Children = > 15 mL/cmH2O
What does the PIP/PP waveform look like when resistance is increased
Examples
PIP = increased PP = no change
Ex: kinked ett, bronchospasm, bronchial secretions, foreign body aspiration, airway compression
What does the PIP/PP waveform look like in the following situations Kinked ETT Bronchospasm Bronchial secretions Foreign body aspiration Airway compression
PIP = increased PP = no change
What does the PIP/PP waveform look like when compliance is decreased
Examples
PIP = increased PP = increased
Ex: Endobronchial intubation, pulmonary edema, effusion, PTX, atelectasis, insufflation, ascites, T-burg, inadequate relaxation
What does the PIP/PP waveform look like in the following situations: Endobronchial intubation PTX Pulm edema Atelectasis Insufflation T-burg
Both PIP and PP increased
What 3 physiologic processes are assessed by EtCO2
Metabolism
Circulation
Ventilation
What does an increased alpha angle on the EtCO2 suggest
Expiratory airway obstruction
What does an increased beta angle on the EtCO2 suggest
Rebreathing d/t faulty inspiratory valve
What is measured during phase I of the EtCO2 waveform
Exhalation of anatomic dead space
What is measured during phase II of the EtCO2 waveform
Exhalation of anatomic dead space + alveolar gas
What is measured during phase III of the EtCO2 waveform
Exhalation of alveolar gas