Hypotension is the most common complications after spinal anesthesia especially in pregnant patients who undergoing cesarean section. Position during spinal anesthesia may be altering the hemodynamic. For right lateral decubitus, the enlarged uterus compresses inferior vena cava that may decrease venous return and cardiac output. This leads to hypotension.The hypothesis is the right lateral position during spinal anesthesia in pregnant women will be had hemodynamic changing more than the left lateral position. This objective is to compare hemodynamic change between left and right lateral position during spinal anesthesia in pregnant women undergoing cesarean section.

Study design: A randomized controlled trial

Study setting:

The study will be conducted in the operating rooms at Songklanagarind Hospital, Faculty of Medicine, Prince of Songkla University, Songkhla, Thailand

Study period:

The total duration of participation in the randomized study is up to the operative day.

Study population:

Pregnant patients undergoing cesarean section receiving spinal anesthesia with 0.5% bupivacaine and 0.2 mg morphine total volume 2.2 ml.

Study sample:

Inclusion criteria

1. Signed informed consent
2. Pregnancy
3. Spinal anesthesia with 0.5% bupivacaine and 0.2 mg morphine total volume 2.2 ml
4. Elective and emergency surgery

Exclusion criteria

1. Contraindication for spinal anesthesia
2. Complicated pregnancy such as maternal heart disease, eclampsia, severe fetal distress, abruption placenta, twin pregnancy, and placenta previa totalis
3. Maternal height < 150 cm.

Inclusion Criteria:

• Signed informed consent
• Term pregnancy
• Spinal anesthesia with 0.5% bupivacaine and 0.2 mg morphine total volume 2.2 ml

Exclusion Criteria:

• Contraindication for spinal anesthesia
• Height < 150 cm.
• Complicated pregnancy e.g. heart disease, preclampsia, eclampsia, diabetes millitus, twin, abrupt placenta, placenta pre via, and fetal distress
• Failed spinal anesthesia