Transcript Pressure vs. Volume Control Ventilation Is one safer than the other?

Patrick Gleason MS4
University of South Carolina
School of Medicine
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Modes of Ventilation
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Ventilator Induced Lung Injury (VILI)
2 main types of injury:
1. Overdistention
2. Collapse and reexpansion
 VILI is histologically indistinguishable from
ARDS
 Obesity may be protective at high pressures
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Pressure Limited Ventilation
Set Peak Inspiratory Pressure
(PIP) level, I:E ratio,
respiratory rate, applied PEEP,
and FiO2
 Tidal volume is variable from
breath to breath
 No consensus on ideal
pressures
 Peak airway pressure is
constant during pressure
limited ventilation
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Volume Limited Ventilation
Set peak flow rate, flow pattern, tidal volume,
respiratory rate, PEEP, and FiO2.
 PIP is variable from breath to breath
 Important distinction in the flow patterns:
 Square wave vs. ramp wave
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Volume Limited Ventilation – cont.
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Pressure vs. Volume
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There were no statistically significant differences in
mortality, oxygenation, or work of breathing
Pressure-limited ventilation was associated with lower
peak airway pressures, a more homogeneous gas
distribution, improved patient-ventilator synchrony, and
earlier liberation from mechanical ventilation than
volume-limited ventilation.
Studies comparing pressure-limited and volume-limited
ventilation used a square wave pattern for both modes.
When volume-limited mechanical ventilation with a ramp
wave pattern was compared to pressure-limited
ventilation, lower peak airway pressures were no longer
an advantage of pressure-limited ventilation.
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Recommendations
Use PEEP in both pressure and volume limited
ventilation – the higher the PIP, the higher the
PEEP.
 Tidal volumes should be between 5-10 mL/kg
of IBW
 Preferable to use either pressure limited or
volume limited with ramp wave flow
 Previous pulmonary injury increases risk for
subsequent VILI
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References
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Hagberg CA. Benumof’s Airway Management: Principles and Practice.
2nd Edition Mosby Elesevier. 1996
Rappaport SH, Shpiner R, Yoshihara G, Wright J, Chang P, Abraham E.
Randomized, prospective trial of pressure-limited versus volumecontrolled ventilation in severe respiratory failure. Crit Care Med.
1994;22(1):22.
Prella M, Feihl, Domenighetti G. Effects of short-term pressurecontrolled ventilation on gas exchange, airway pressures, and gas
distribution in patients with acute lung injury/ARDS: comparison with
volume-controlled ventilation. Chest. 2002;122(4):1382.
Chiumello D, Pelosi P, Calvi E, Bigatello LM, Gattinoni L. Different
modes of assisted ventilation in patients with acute respiratory failure.
Eur Respir J. 2002;20(4):925.
Bozyk P, Hyzy RC, Parsons P, Wilson, K. Modes of Ventilation.
UpToDate 2010.
Medscape
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