PSV and SIMV Setup Verification

Key Points

  • PSV and SIMV require explicit verification of directly set parameters and separate tracking of observed outputs.
  • In PSV, all breaths are patient-triggered; work-of-breathing tolerance must be reassessed continuously.
  • In SIMV, mandatory windows are synchronized with spontaneous effort, but poor synchrony can increase effort burden.

Equipment

  • Ventilator with active PSV or SIMV mode display
  • Current provider order for mode-specific set parameters
  • Continuous respiratory monitoring (rate, volume trend, pressure trend)
  • Documentation workflow for set-versus-observed variables

Procedure Steps

  1. Confirm the ordered spontaneous mode (PSV or SIMV) and verify patient appropriateness for spontaneous breathing support.
  2. For PSV, verify directly set parameters: pressure support, PEEP, and FiO2.
  3. For PSV, document observed-not-set outputs: tidal volume, inspiratory flow or I-time, RR, PIP, and I:E.
  4. For SIMV, verify directly set parameters: RR, Vt or inspiratory pressure, PEEP, FiO2, and pressure support.
  5. For SIMV, document observed-not-set outputs: PIP and I-time (when flow, rather than I-time, is set).
  6. Assess ventilator-patient synchrony during spontaneous and mandatory breath windows.
  7. Evaluate work of breathing and signs of fatigue after setup verification.
  8. Notify team promptly if observed values suggest mode intolerance or synchrony failure.
  9. Repeat verification after any adjustment and at every handoff.

Common Errors

  • Treating observed variables as fixed settings delayed detection of unsafe trend changes.
  • Ignoring increasing work of breathing in spontaneous modes preventable fatigue and failure.
  • Missing synchrony mismatch in SIMV elevated effort and prolonged ventilator dependence.
  • Failing to re-verify after adjustments mismatch between order and delivered support.