Low
tidal volume positive end-expiratory pressure versus high
tidal volume zero-positive end-expiratory pressure and postoperative pulmonary functions in robot-assisted laparoscopic radical prostatectomy.
Current guidelines recommend a
tidal volume of 6 mL [kg.sup.-1] for the management of patients with acute lung injury or acute respiratory distress syndrome (19).
The conventional SVV threshold values in the prediction of fluid responsiveness are ranged from 10% to 13%.[32] However, the SVV value and threshold to discriminate fluid responsiveness in low
tidal volume setting may be decreased.[33],[34] Therefore, the threshold value of SVV should be interpreted carefully during OLV.
Although low
tidal volume (VT) has been proved to decrease ARDS mortality, 6 ml/kg predicted body weight (PBW) VT is not suitable for all ARDS patients.
Effects of different
tidal volumes for one-lung ventilation on oxygenation with open chest condition and surgical manipulation: a randomised cross-over trial.
However, the
tidal volume suddenly decreased from 450 to 120 ml at sternal closure, and the end-expiratory carbon dioxide pressure increased from 39 to 71 mmHg.
Although, low
tidal volume is an important determinant of mortality reduction, it has been shown that reductions in
tidal volume or increases in PEEP are beneficial only if associated with a driving pressure (plateau pressure- PEEP) lower than 16 cm [H.sub.2]O.
Moreover, the dead space may be decreased in pregnancy because of increased cardiac output and better perfusion in the apices, so the ratio of dead space volume to the
tidal volume becomes even more advantageous.
It is a mode of ventilation controlled by
tidal volume and respiratory frequency as constant parameters, with variable inspiratory pressures.
IVC CI IVCmax Underestimate intravascular volume Increased
tidal volume Increased?
The major obstacle for performing low
tidal volume ventilation is carbon dioxide retention, worsened oxygenation, and intrapulmonary shunt [44].
In acute respiratory distress syndrome (ARDS), BPFs can cause incomplete lung expansion, loss of effective
tidal volume and positive end expiratory pressure (PEEP), and reduced carbon dioxide elimination [5].
