Whether the usage of non-invasive arterial blood pressure monitor to guide fluid therapy in caesarean section can effectively reduce the incidence of hypotension and fetal complications.

Spinal anesthesia in the cesarean section often causes significant peripheral vascular dilatation, decreases blood pressure and cardiac output reduction which leads to maternal nausea, vomiting, dizziness and uteroplacental hypoperfusion. Infusion therapy and the use of vasopressor can prevent and treat the incidence of hypotension. Appropriate fluid therapy can not only maintain maternal tissue perfusion, but also reduce uteroplacental hypoperfusion. In the present study, perioperative goal directed fluid therapy is used. The non-invasive continuous hemodynamic monitor is used in this study, and the parameters (blood pressure (BP), stroke volume(SV), stroke volume variation (SVV), cardiac output (CO)) are used to determine the parameters of the blood transfusion in cesarean section as infusion guidelines. The application of Clearsight system to the pre-infusion of target-guided crystalloid solution is compared with the infusion of quantitative crystalline solution in the hope of reducing the incidence of maternal hypotension, reducing the use of vasopressin, improving uteroplacental perfusion and reducing the incidence of fetal acidosis.

Inclusion criteria:

1. 20-45 y/o parturient
2. Receive spinal anesthesia (SA) or combined spinal-epidural anesthesia (CSA) to undergo cesarean section

Exclusion criteria:

1. Emergent C/S
2. BMI>35kg/m2
3. Height <150cm or >175 cm
4. Patients with major cardiovascular disease, preeclampsia or eclampsia.
5. Gestational age < 36wks
6. Multiple pregnancy