Basic of Mechanical Basic of Mechanical VentilatorVentilator

Dr. Kriangsak AtipornwanichRajavithi Hospital

Mechanical Ventilators (MV)Mechanical Ventilators (MV)

IndicationIndication forfor mechanicalmechanical ventilationventilation

Hypoxic respiratory failure Hypercapnic respiratory failure

Hypoxic respiratory failureHypoxic respiratory failure

PaO2 < 60 mmHg at FiO2 > 0.5 (A-a)O2 > 350 mmHg at FiO2 1.0 PaO2/FiO2 < 200

HypercapnicHypercapnic respiratory failurerespiratory failure

Tidal volume < 5 ml/kg Vital capacity < 10 ml/kg Minute volume < 5 l/min Respiratory rate > 35 /min Breathing pattern : abdominal paradox

Mechanical ventilationMechanical ventilation

Positive pressure ventilation Tidal volume ( volume target or pressure

target) Respiratory rate

Normal Respiration : negative Normal Respiration : negative pressure inspirationpressure inspiration

MV: Positive pressure ventilationMV: Positive pressure ventilation

Breath typeBreath type

Controlled mandatory breath Assisted mandatory breath Spontaneous breath

ControlleControlle mandatory breath VS mandatory breath VS Assisted mandatory breathAssisted mandatory breath

Spontaneous breathSpontaneous breath

ClassificationClassification

Phase Variables Phase Variables 4 phase4 phase

1. trigger2. limit3. cycle4. baseline

Pressure(cmH2O)

1

2

3Expiration phaseInspiration phase

Insp. --> Exp.

4 Exp. --> Insp.

Ventilator phase variables

Trigger

1. Time-triggered2. Pressure-triggered3. Flow-triggered

1.Volume-cycled

1. Volume-limited

2. Pressure-limited

3. Flow-limited

2.Pressure-cycled3.Time-cycled4. Flow-cycled

Limit Cycle Baseline

1. PEEP +

2. ZEEP 0

Type of ventilationsType of ventilations

Conventional mechanical Conventional mechanical ventilationventilation

Fully support ventilations Partial support ventilations

Fully support ventilationsFully support ventilations

tidal volume respiratory rate Continuous mandatory ventilation (CMV) Assist-controlled mandatory ventilation (ACV) tidal volume volume or pressure Volume control ventilation (VCV, V-ACV) Pressure control ventilation (PCV, P-ACV)

Continuous Mandatory Ventilation (CMV)Continuous Mandatory Ventilation (CMV)Volume controlVolume control (VCV)(VCV)

Continuous Mandatory Ventilation (CMV)Continuous Mandatory Ventilation (CMV)Pressure control (PCV)Pressure control (PCV)

AssistAssist--Control Mandatory Ventilation (ACV), Control Mandatory Ventilation (ACV), Volume control (VVolume control (V--ACV)ACV)

AssistAssist--Control Mandatory Ventilation (ACV), Control Mandatory Ventilation (ACV), Pressure control (Pressure control (PP--ACV)ACV)

Partial support ventilationsPartial support ventilations

(spontaneous breath)

Synchronized intermittent mandatory ventilation (SIMV)

Pressure support ventilation (PSV) Continuous positive airway pressure

(CPAP)

Synchronized Intermittent Mandatory Synchronized Intermittent Mandatory Ventilation (SIMV)Ventilation (SIMV)

Pressure Support VentilationPressure Support Ventilation(PSV)(PSV)

SIMV plus PSVSIMV plus PSV

Continuous Positive Airway Continuous Positive Airway Pressure (CPAP)Pressure (CPAP)

Initial Setting of Initial Setting of MechanicalMechanical VentilationVentilation

Ventilator setting Recommendation Tidal Volume 8 - 10 ml/Kg Respiratory rate 12 20 breaths/min Flow rate 60 L/min I:E 1 : 2 Flow profile Decelerating wave Sensitivity - 1 to - 2 cmH2O FiO2 0.4 1.0 keep SaO2 > 90% PEEP 3 - 5 cmH2O

THE ENDTHE END

Basic of Mechanical VentilatorMechanical Ventilators (MV)Indication for mechanical ventilationHypoxic respiratory failureHypercapnic respiratory failureMechanical ventilationNormal Respiration : negative pressure inspirationMV: Positive pressure ventilationBreath type Controlle mandatory breath VS Assisted mandatory breathSpontaneous breathClassification Phase Variables 4 phaseType of ventilationsConventional mechanical ventilationFully support ventilationsContinuous Mandatory Ventilation (CMV)Volume control (VCV)Continuous Mandatory Ventilation (CMV)Pressure control (PCV)Assist-Control Mandatory Ventilation (ACV), Volume control (V-ACV)Assist-Control Mandatory Ventilation (ACV), Pressure control (P-ACV)Partial support ventilationsSynchronized Intermittent Mandatory Ventilation (SIMV)Pressure Support Ventilation(PSV)SIMV plus PSVContinuous Positive Airway Pressure (CPAP)Initial Setting of Mechanical VentilationTHE END