Mechanical Ventilation: Maxims, Phases, and Variables

These flashcards capture key terminology and concepts related to mechanical ventilation, encompassing maxims, phases, and operational variables.

Mechanical Ventilator

A machine designed to assist or replace a patient's breathing.

Energy Source

The input power that drives the mechanical ventilator.

Conversion Mechanism

Part of the ventilator that controls pressure and flow.

Monitoring System

Technology for assessing device performance and patient condition.

Maxim 1: Definition of a Breath

A breath is one cycle of positive flow (inspiration) and negative flow (expiration).

Inspiration

Positive flow of air into the lungs.

Expiration

Negative flow of air out of the lungs.

Inspiratory Phase

Phase where a drive mechanism creates a positive pressure gradient.

Changeover Phase

Transition from inspiratory phase to expiratory phase.

Expiratory Phase

Phase where expiration occurs passively, similar to spontaneous breathing.

Assisted Breathing

When the ventilator provides some or all of the work of breathing.

Partial Assist

When the patient initiates a breath while the ventilator supports breathing.

Full Assist

When the ventilator provides all the work for breathing.

Pressure Control

A ventilation mode where inspiratory pressure is predetermined.

Volume Control

A mode where inspiratory volume and flow are preset.

Equation of Motion

A formula used to determine the relationship between pressure, flow, and volume in ventilation.

Control Variables

Limiting factors that determine how much is delivered to the patient.

Volume Control Ventilation

Provides a set tidal volume, useful for patients with varying lung mechanics.

Pressure Control Ventilation

Delivers gas at a set pressure for a specified time.

Inspiratory Time (TI)

The duration for which a breath is delivered during inspiration.

Cycle Mechanisms

Processes that determine the transition from inspiration to expiration.

Trigger Mechanisms

Factors that initiate the inspiratory phase of breathing.

Patient Triggered

Inspiration initiated by the patient's effort.

Machine Triggered

Inspiration initiated automatically based on machine settings.

Mandatory Breaths

Breaths controlled by the machine with little to no patient control.

Spontaneous Breaths

Breaths where the patient retains control over timing.

Continuous Mandatory Ventilation (CMV)

All breaths are mandatory, with no spontaneous breaths allowed.

Intermittent Mandatory Ventilation (IMV)

Combines mandatory and spontaneous breaths.

Continuous Spontaneous Ventilation (CSV)

All breaths are spontaneous.

Ventilatory Patterns

Basic patterns that underlie complex ventilation modes.

Targeting Schemes

Methods used to optimize ventilator output based on patient needs.

Closed-loop Ventilation

Automatic adjustment of ventilator settings based on patient feedback.

Peak Flow (PF)

The speed of delivered gas during inspiration.

Positive End Expiratory Pressure (PEEP)

Pressure remaining in the lungs at the end of expiration.

Fractional Inspired Oxygen (FiO2)

The concentration of oxygen delivered to the patient with each breath.