The Effect of Left Uterine Displacement on Parturient Cardiovascular System

At operating room, patients will be monitored using non invasive blood, ECG, pulse oximeter and electrical cardiometry. Baseline readings will be taken in supine position then repeated after putting the patient in left lateral position with angle 15 then 30 degrees.

Then two IV lines will be inserted and 500cc crystalloid will be administered. Subarachnoid block will be performed in sitting position under complete aseptic conditions using 25 g spinal needle. Subarachnoid block will be achieved by injecting 10 mg hyperbaric bupivacaine plus 25 ug fentanyl. The block will be considered successful if adequate block reached T4 dermatome.

After successful block the hemodynamic variables will be recorded in the same positions as before (0,15, 30 degrees left uterine tilt).

A minimum number of 61 patients was calculated to have a study power of 80% and alpha error of 0.05.

SPSS Chicago 18 software will be used for data analysis. Categorical data will be presented as frequencies, continuous variables will presented as mean ± standard deviation and will be analyzed using on way analysis of variance (ANOVA) with post-hoc pairwise comparisons using bonferroni test. A P value of 0.05 will be considered statistically significant.

Inclusion criteria

• full term, singleton, American society of anesthesiologists (ASA) I and II pregnant women scheduled for cs

Exclusion criteria

• BMI > 35 Kg/m2
• polyhydramnios
• history of impaired cardiac contractility
• valvular heart disease
• cardiac arrhythmias
• hypertensive pregnancy disorders
• fetal abnormalities