RT Journal Article
SR Electronic
T1 Work of Breathing During Lung-Protective Ventilation in Patients With Acute Lung Injury and Acute Respiratory Distress Syndrome: A Comparison Between Volume and Pressure-Regulated Breathing Modes
JF Respiratory Care
FD American Association for Respiratory Care
SP 1623
OP 1631
VO 50
IS 12
A1 Richard H Kallet
A1 Andre R Campbell
A1 Rochelle A Dicker
A1 Jeffrey A Katz
A1 Robert C Mackersie
YR 2005
UL http://rc.rcjournal.com/content/50/12/1623.abstract
AB BACKGROUND: Pressure-control ventilation (PCV) and pressure-regulated volume-control (PRVC) ventilation are used during lung-protective ventilation because the high, variable, peak inspiratory flow rate (V˙I) may reduce patient work of breathing (WOB) more than the fixed V˙I of volume-control ventilation (VCV). Patient-triggered breaths during PCV and PRVC may result in excessive tidal volume (VT) delivery unless the inspiratory pressure is reduced, which in turn may decrease the peak V˙I. We tested whether PCV and PRVC reduce WOB better than VCV with a high, fixed peak V˙I (75 L/min) while also maintaining a low VT target. METHODS: Fourteen nonconsecutive patients with acute lung injury or acute respiratory distress syndrome were studied prospectively, using a random presentation of ventilator modes in a crossover, repeated-measures design. A target VT of 6.4 ± 0.5 mL/kg was set during VCV and PRVC. During PCV the inspiratory pressure was set to achieve the same VT. WOB and other variables were measured with a pulmonary mechanics monitor (Bicore CP-100). RESULTS: There was a nonsignificant trend toward higher WOB (in J/L) during PCV (1.27 ± 0.58 J/L) and PRVC (1.35 ± 0.60 J/L), compared to VCV (1.09 ± 0.59 J/L). While mean VT was not statistically different between modes, in 40% of patients, VT markedly exceeded the lung-protective ventilation target during PRVC and PCV. CONCLUSIONS: During lung-protective ventilation, PCV and PRVC offer no advantage in reducing WOB, compared to VCV with a high flow rate, and in some patients did not allow control of VT to be as precise.