Lecture on End-Tidal CO2 Monitoring and Ventilator Asynchrony

These flashcards cover key terms and concepts related to End-Tidal CO2 monitoring and ventilator asynchrony, essential for understanding respiratory management in clinical settings.

End-Tidal CO2 (ETCO₂) Monitoring

A noninvasive technique to measure the concentration of CO₂ in exhaled air at the end of expiration.

Capnography

The graphical representation of carbon dioxide levels (ETCO₂) in exhaled air.

Capnometry

The numerical measurement of carbon dioxide concentration in exhaled air.

Arterial CO₂ (PaCO₂)

The concentration of carbon dioxide in arterial blood, typically higher than ETCO₂ due to dead space.

Dead Space

Areas of the respiratory system where air is present but no gas exchange occurs, contributing to the discrepancy between ETCO₂ and PaCO₂.

Hypoventilation

A condition where ventilation is inadequate to perform proper gas exchange, often indicated by elevated ETCO₂.

Hyperventilation

Rapid or deep breathing that exceeds metabolic needs, leading to low ETCO₂ levels.

Pulmonary Embolism

An obstruction in the pulmonary artery that can lead to decreased ETCO₂ due to reduced perfusion.

Waveform (Capnogram)

The graphical representation of the CO₂ levels throughout the breath cycle, divided into four phases.

Phase I of ETCO₂ Waveform

Baseline phase where no CO₂ is detected, corresponding to dead space ventilation.

Phase II of ETCO₂ Waveform

Expiratory upstroke phase where CO₂-rich alveolar gas begins to mix with dead space air.

Phase III of ETCO₂ Waveform

Alveolar plateau phase indicating effective alveolar gas exchange; highest point is ETCO₂.

Respiratory Failure

A clinical condition where gas exchange is severely impaired, often detected early with continuous ETCO₂ monitoring.

Ventilator Asynchrony

A mismatch between patient respiratory efforts and ventilator support, causing increased work of breathing.

Auto-PEEP

Intrinsic positive end-expiratory pressure resulting from incomplete exhalation, which can contribute to asynchrony.

Flow Asynchrony

Occurs when the flow provided by the ventilator does not meet the patient's demand.

Trigger Asynchrony

A type of asynchrony where there is a delay or failure in the ventilator responding to the patient's efforts.

Mode Asynchrony

Selection of a ventilation mode that does not adequately support the patient's respiratory needs.

Spontaneous Breathing Trials (SBT)

A method to assess a patient's readiness to be liberated from mechanical ventilation.

Rapid Shallow Breathing Index (RSBI)

A parameter used to predict weaning success; values < 100 suggest better chances of successful extubation.

Lung Recruitment Maneuvers

Techniques intended to reopen collapsed alveoli to improve oxygenation in mechanically ventilated patients.

Pressure Regulated Volume Control (PRVC)

A mode of ventilation that targets to deliver preset tidal volumes at the lowest possible pressure.

Tidal Volume (VT)

The volume of air delivered to the patient with each breath.

Peak Inspiratory Pressure (PIP)

The maximum pressure achieved during inhalation.

Plateau Pressure

The pressure measured at the alveoli during an inspiratory pause; should be <28 cmH₂O.

VAP (Ventilator-Associated Pneumonia)

A potential complication of mechanical ventilation, caused by infection.

FIO₂

Fraction of inspired oxygen; the percentage of oxygen in the air that a patient breathes.