Static and Dynamic Compliance Flashcards

Study Notes

PIP for Volume Ventilation

PIP (Peak Inspiratory Pressure) indicates highest pressure during inspiration.
Used to calculate dynamic compliance (CD).
Represents pressure needed to deliver a specific tidal volume.

Dynamic Compliance

Reflects lung and chest wall recoil, affected by airway resistance and equipment.
Conditions like mucus plugs and bronchoconstriction can alter measurements.

Plateau Pressure (Pplat)

Measured at end of inspiration, should never exceed PIP.
Indicates static conditions with no gas flow during measurement.
Essential for calculating static compliance (Cs); increased plateau suggests decreased compliance.

Static Compliance (Cs)

Calculated as exhaled volume divided by (Plateau pressure - PEEP).
Normal range: 70-100 mL/cm H2O; Kettering suggests 60-100 mL/cm H2O.
Values < 25 mL/cm H2O indicate high work of breathing (WOB).

Dynamic Compliance (CD)

Calculated as exhaled volume divided by (PIP - PEEP).
Normal airway resistance is typically 6-2.4 cm H2O/L/sec; intubated patients may see increased values up to 6.0.

Both PIP and Plateau Increased

Indicates decreasing compliance.
Potential causes: atelectasis, pulmonary edema, pneumonia, ARDS.
Treatment includes increasing PEEP and addressing underlying issues.

PIP Increased, Plateau Unchanged

Suggests increased airway resistance.
Conditions: bronchospasm, secretions, kinked endotracheal tube (ETT), foreign body aspiration.
Treatments vary based on the cause, such as beta agonists for bronchospasm.

Airway Resistance Calculation Requirements

Necessary: PIP, Plateau, and flow rate (L/min).
Example calculation shows a difference of 1 cm H2O/L/sec for PIP 35 and Plateau 34, given a flow of 30 L/min.

Calculating Airway Resistance Formula

Formula: PTA (PIP - Plateau) divided by Flow (L/sec).
Example yields airway resistance of 2 cm H2O/L/sec.

Assessing Airway Resistance in Patients

Greatest airway resistance indicated by the largest PIP-Plateau difference; highest concern in patients with PIP 40 and Plateau 30.

Calculating Static Compliance (Cs)

Example: Vt (600 mL), PIP (25 cm H2O), Plateau (15 cm H2O), PEEP (5 cm H2O).
Resulting Cs = 60 mL/cm H2O.

Calculating Airway Resistance with Given Values

Example: Vt (500 mL), PIP (40 cm H2O), Plateau (25 cm H2O), PEEP (5 cm H2O).
Resulting airway resistance calculated as 18.07 cm H2O/L/sec; indicates potential bronchospasm.

Difference Between PIP and Plateau Pressure

Reflects resistance to flow entering the lung parenchyma.

Dynamic Compliance Calculation

Dynamic compliance determined using PIP measurements.

PIP Reflection

PIP provides insight into tidal volume compliance and flow resistance.

Plateau Value Usage

Plateau pressure measurement is essential for calculating static compliance.

Inverse Relationship

Static compliance has an inverse relationship with plateau pressure.

Impact of Increased Plateau Pressure

Elevated plateau pressure decreases compliance, indicating lung stiffening.
Conditions: ARDS, pulmonary edema, restrictive lung diseases, and pneumonia.

Inspiratory Pause Maneuver

Used to obtain plateau pressure effectively.

Volume Trauma Risk

Plateau pressures exceeding 30 cm H2O may cause lung injury.

Management with High Plateau

If plateau pressure is over 30, consider reducing tidal volume or inspiratory pressure in volume control ventilation.

PEEP Considerations

Patients with plateau pressures over 30 require more PEEP for oxygenation; may experience difficulty during bagging.

Ambu Bag Usage

PEEP valve needed on ambu bag if the PEEP exceeds 5.

Implications of Static Compliance

Static compliance values below 25 indicate very high WOB for the patient.

Airway Resistance Calculation Simplified

Airway resistance formula: (PIP - Plateau Pressure) / (Flow/60).

Description

Explore key concepts in static and dynamic compliance with these flashcards. Learn important terms such as PIP for volume ventilation and the definition of dynamic compliance. Perfect for students of respiratory care and those preparing for exams.

Static and Dynamic Compliance Flashcards

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Questions and Answers

What does PIP stand for in volume ventilation?

What is dynamic compliance?

What is plateau pressure (Pplat)?

Static compliance is calculated using the formula: Exhaled volume divided by _____.

What does increasing plateau pressure indicate?

Which of the following patients has the biggest problem with airway resistance?

To calculate airway resistance, you need PIP, plateau, and _____ provided in L/min.

What does a static compliance value less than 25 mL/cm H2O indicate?

What is the formula for calculating airway resistance?

What does PIP reflect?

What should be done if plateau pressure is over 30 cm H2O?