10 - Introduction to Mechanical Ventilation (1/2)

indications for mechanical ventilation (MV)

• respiratory failure

  • type I = hypoxemia

  • type II = hypercapnia

• airway protection (ie, coma)

• respiratory muscle fatigue

volume control ventilation (VCV)

MV mode with fixed volume regardless of pressure

submodes of VCV

• AC/VC (assist control/volume control)

• SIMV (synchronized intermittent mandatory ventilation)

benefits of VCV

consistant tidal volume

limitations of VCV

risk of barotrauma

pressure control ventilation (PCV)

MV mode with fixed pressure and variable volume

submodes of PCV

APRV (airway pressure release ventilation)

benefits of PCV

low risk of barotrauma

limitations of PCV

variable tidal volume

VCV graph for pressure

VCV graph for volume

VCV graph for flow

PCV graph for pressure

PCV graph for volume

PCV graph for flow

initial MV settings

• V_T = 6-8 mL/kg IBW

• PEEP = 5-10 cmH₂O

• F_iO₂ = start at 100% then titrate down

• RR = 12-20 b/min

causes of high pressure alarms

• secretions

• bronchospasm

• kinked tubing

management of high pressure alarms

• suctioning

• assess tubing

causes of low pressure alarms

• disconnection

• cuff leak

management of low pressure alarms

• reconnect tubes

• check cuff

ventilation strategies

• ARDS

  • low V_T (4-6 mL/kg)

  • high PEEP

• COPD exacerbation

  • long expiratory time

  • low RR

• pediatric ventilation

  • small V_T

  • high RR

determining when to wean from MV

• spontaneous breathing trials (SBTs)

• criteria

  • stable ABGs

  • minimal PEEP

  • low F_iO₂