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%. However, the SVV value and threshold to discriminate fluid responsiveness in low tidal volume
setting may be decreased., 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
The major obstacle for performing low tidal volume
ventilation is carbon dioxide retention, worsened oxygenation, and intrapulmonary shunt .
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 .