Clinical Characteristics of Commonly Used Modes of Mechanical Ventilation
| Ventilator Mode | Independent Variables (Set by User) | Dependent Variables (Monitored by User) | Trigger/Cycle Limit | Advantages | Disadvantages |
|---|---|---|---|---|---|
| ACMV | FIO2 Tidal volume Ventilator rate Level of PEEP Inspiratory flow pattern Peak inspiratory flow Pressure limit | Peak airway pressure Minute ventilation Plateau pressure Mean airway pressure I/E ratio | Pt effort Timer Pressure limit | Timer backup Pt-vent synchrony Pt controls minute ventilation | Not useful for weaning Potential for dangerous respiratory alkalosis due to hyperventilation Barotrauma risk |
| SIMV | Same as for ACMV | Same as for ACMV | Same as for ACMV | Timer backup is useful for weaning Comfort from spontaneous breaths | Potential dyssynchrony |
| PSV | FIO2 Inspiratory pressure level PEEP pressure limit | Tidal volume Respiratory rate Minute ventilation ABG | Inspiratory flow Pressure limit | Assures synchrony Good for weaning | No timer backup; may result in hypoventilation |
| NIV | Inspiratory and expiratory pressure levels FIO2 | Tidal volume Respiratory rate I/E ratio Minute ventilation ABG | Pressure limit Inspiratory flow | Pt control | Discomfort and bruising from mask Leaks are common Hypoventilation risk |
Abbreviations: ACMV, assist-control mandatory ventilation; I/E, inspiration/expiration; FIO2, inspired O2; NIV, noninvasive ventilation; PEEP, positive end-expiratory pressure; PSV, pressure-support ventilation; SIMV, synchronized intermittent mandatory ventilation.