Assist-Control Ventilator Initial Settings Check

Key Points

• Initial assist-control checks confirm that ordered parameters are correctly entered and mode-specific expected variables are monitored.
• AC volume control and AC pressure control use different control variables and different observed outcomes.
• Pressure safety surveillance is required to reduce ventilator-induced alveolar injury risk.

Equipment

• Mechanical ventilator with active AC mode configuration
• Current order set for mode, respiratory rate, FiO2, PEEP, and mode-specific controls
• Bedside documentation tool for set vs observed values and trend reassessment
• Team escalation pathway for unsafe pressure or ineffective ventilation trends

Procedure Steps

1. Verify invasive airway placement and readiness for full assist-control ventilation support.
2. Confirm selected mode (ACVC/VC/CMV-VC or ACPC/PCV/CMV-PC) matches ordered plan.
3. In AC volume control, verify directly set parameters: RR, tidal volume, max flow or inspiratory time, PEEP, and FiO2.
4. In AC pressure control, verify directly set parameters: RR, pressure control, inspiratory time, PEEP, and FiO2.
5. Identify mode-specific monitored variables that are observed but not directly set (for example pressure trends in VC, tidal volume trends in PC).
6. Reassess pressure safety values and ensure plateau pressure targets remain in safe range (ideally below 30 cm H2O, maximum around 35 cm H2O in this source).
7. Evaluate trend response to changing compliance and resistance, then communicate significant changes promptly.
8. Document mode, set values, observed values, and immediate reassessment findings.
9. Repeat checks after any setting adjustment and at each handoff.

Common Errors

• Entering incorrect control variable for selected mode → ineffective or unsafe ventilation delivery.
• Failing to trend observed variables (pressure in VC, volume in PC) → delayed recognition of deterioration.
• Ignoring rising pressure thresholds → increased alveolar injury risk.
• Not rechecking settings after adjustments → persistent mismatch between order and ventilator state.

Related

• invasive-mechanical-ventilation-modes - Concept-level comparison of volume-control and pressure-control behavior.
• advanced-airways-and-intubation - Definitive airway foundation required before invasive mode management.