Modes of Ventilation

Flashcards about Modes of Ventilation

What framework is used for making a selection regarding ventilatory support?

Why does the patient need ventilatory support? Does the problem require a special mode? What goals can be achieved? Does the patient need intubation? Where will support be provided? Will it be brief or long-term? How familiar is the staff with the ventilator?

What decisions need to be made regarding mechanical ventilation?

Are indications present? Use noninvasive or invasive ventilation? Type and method to establish airway? Pressure or volume ventilation? Partial or full ventilatory support? Mode of ventilation? Select appropriate ventilator settings for mode. Set appropriate alarm and backup values.

What are the keys to lung protection during mechanical ventilation?

Transpulmonary pressure less than 27 cm H2O, A driving pressure of less than 15 cm H2O, Plateau pressure less than 28 cm H2O, A tidal volume of 4 to 8 ml/kg of IBW, A PEEP set to avoid derecruitment during exhalation

What are two methods of administering Noninvasive Positive Pressure Ventilation (NIV)?

Continuous positive airway pressure (CPAP) and Noninvasive positive pressure ventilation (NIV)

What types of ventilators are used for NIV?

Pressure-triggered, pressure-limited, flow-cycled devices and Critical care ventilators that contain NIV modes

Name disorders sometimes managed with NIV

Chronic Respiratory Failure, Chest Wall Deformities, Neuromuscular Disorders, Central Alveolar Hyperventilation, Chronic Obstructive Pulmonary Disease (COPD), Cystic Fibrosis, Bronchiectasis, Acute Respiratory Failure (ARF), Acute Respiratory Distress Syndrome (ARDS), Pneumonia, Post-Operative Complications, Asthma, Cardiogenic Pulmonary Edema, Heart Failure, Post Extubation Failure/Complications, Obstructive Sleep Apnea

What are advantages of NIV?

Avoids complications associated with artificial airways, Provides flexibility in initiating or removing mechanical ventilation, Reduces requirements for heavy sedation, Preserves airways defense mechanisms: speech and swallowing

What are disadvantages of NIV?

Gastric Distension, Skin Irritation/Pressure Sores, Dry nose/eyes, Claustrophobia, Discomfort, poor sleep (leaks)

Define Full Ventilatory Support (FVS)

Ventilator provides all the energy necessary to maintain effective alveolar ventilation

Define Partial Ventilatory Support (PVS)

Only a portion of the work is done by the ventilator

What are the different types of breath delivery?

Mandatory, Spontaneous, Assisted

Differentiate Mandatory Breath Delivery

Ventilator controls: timing, tidal volume or inspiratory pressure - or in other words, inspiration is machine triggered, limited and/or machine cycled

Differentiate Assisted Breath Delivery

Has characteristics of both mandatory and spontaneous. All or part of the breath is generated by the ventilator - Allows patient to breath above set rate, but may increase WOB / dyssynchrony if not set correctly

Differentiate Spontaneous Breath Delivery

Patient controls: the timing and the tidal volume. Based on patient demand and the patient’s lung characteristics

Volume-controlled ventilation

Volume is constant, pressure will fluctuate based on patient’s lung characteristics. Guarantees a specific volume delivery and volume of expired gas and Can maintain a certain PaCO2

What factors affect pressures during volume controlled ventilation?

Patient Lung Characteristics, Inspiratory Flow Pattern, Volume Setting, Positive end expiratory pressure (PEEP), Auto-PEEP

Pressure-controlled ventilation

Maximum pressure is set as the independent variable. Considered a lung protective strategy and May be more comfortable for the spontaneously breathing patient

What factors affect volumes during pressure controlled ventilation?

Pressure Setting, Pressure Gradient, Patient Lung Characteristics, Inspiratory Time, Active Inspiratory Efforts by patient can produce larger tidal volumes.

Dual controlled ventilation

Mandatory breath has combined limiting/controlling factor (flow and pressure) and the ventilator can switch between control modes

Types of timing for breath delivery

Continuous mandatory ventilation (CMV), Intermittent mandatory ventilation (IMV), Continuous spontaneous ventilation (CSV)

Describe Continuous mandatory ventilation (CMV)

Time- or patient-triggered. Time-Triggered Breaths - Controlled ventilation and Patient-Triggered Breaths - Assisted Ventilation

Describe Intermittent mechanical ventilation (IMV)

Patient receives a set number of mandatory breaths. Can breath spontaneous breaths between mandatory breaths

Describe Continuous spontaneous ventilation (CSV)

All breaths are spontaneous and Patient-triggered

Describe Volume-Controlled Continuous Mandatory Ventilation (VC-CMV)

All breaths are mandatory and If patient triggered, it is called assisted

Describe Pressure-Controlled Continuous Mandatory Ventilation (PC-CMV)

All breaths are time or patient triggered, pressure targeted, and time cycled. The ventilator provides a constant pressure to the patient during inspiration

Describe Intermittent Mandatory Ventilation (IMV)

Involves periodic volume (VC-IMV) or pressure-targeted (PC-IMV) breaths that occur at set intervals (time triggering). The patient can breathe spontaneously between mandatory (i.e., machine) breaths at the desired baseline pressure without receiving a mandatory breath

Describe Synchronized Intermittent Mandatory Ventilation (SIMV)

SIMV operates in the same way as IMV except that mandatory breaths normally are patient or time triggered rather than solely time triggered

Describe Continuous Spontaneous Ventilation (CSV)

Patients can breathe spontaneously through a ventilator circuit without receiving any mandatory breaths (T-Piece)

Describe Pressure Support Ventilation (PSV or PC-CSV)

The ventilator provides a constant pressure during inspiration once it senses that the patient has made an inspiratory effort

What is rise time?

The time required for the ventilator to rise to the set pressure at the beginning of inspiration

Describe Proportional Assist Ventilation (PAV)

Pressure, flow, and volume delivery are proportional to the patient’s spontaneous effort

Describe a Spontaneous Breathing Trial (SBT)

Ventilator support is reduced and the patient is allowed to breathe spontaneously for a brief period (15–30 minutes) while the person’s vital signs, pulse oximetry, and physical appearance are monitored.

Describe Bilevel Positive Airway Pressure

The operator sets two pressure levels: an inspiratory and an expiratory positive airway pressure. Inspiration is typically patient triggered, but can also be time triggered. It can be flow or time cycled.

Describe Pressure-regulated volume control (PRVC)

Patient-triggered or time-triggered, volume-targeted, and time- cycled breaths

Describe Volume-support ventilation (VS-CSV or VSV)

It is a pressure breath that is patient triggered, volume targeted, and flow cycled

Describe Mandatory minute ventilation (MMV)

It allows the operator to set a minimum minute ventilation, which usually is 70% to 90% of a patient’s current VE

Describe Adaptive Support Ventilation

The clinician sets the targeted minute ventilation based on the patient’s ideal body weight and estimated dead space volume

Describe Airway Pressure-Release Ventilation (APRV)

Designed to provide two levels of CPAP and to allow spontaneous breathing at both levels when spontaneous effort is present