Overview
Intercristal line as palpation landmarks to identifying the vertebral level is frequently inaccurate.To find more safe and reliable body surface markers and convenient methods to be solved in clinical work.The investigators performed a two-stage study to evaluated the accuracy of intercristal line and the The Posterior Superior Iliac Spine (PSIS) line to identify the lumbar intervertebral space for spinal anesthesia using ultrasonography in pregnant woman which will provide a second option.
Description
The investigators performed a two-stage study to evaluated the accuracy of Intercristal line and the PSIS line to identify the lumbar intervertebral space for spinal anesthesia using ultrasonography in pregnant woman. In phase 1, the distance between the PSIS line and each intervertebral space(PI) is measured by ultrasound,and the mean and 95% confidence interval of PI in pregnant women with different height ranges were calculated to provide a reference for identifying specific lumbar spaces.In phase 2, a further 180 participants were received the PSIS, Intercristal line or both as palpation landmarks to define specific lumbar spaces.
Eligibility
Inclusion Criteria:
- After obtaining written informed consents,pregnant women at 37-41 weeks of gestation
Exclusion Criteria:
- The patients have contraindications to intraspinal anesthesia , if their lumbar anatomy was potentially compromised by spinal scoliosis, spondylolisthesis, severe disc height reduction, sacralization,lumbarization, previous spinal surgery or osteoporosis with loss of vertebral height or if the patient with BMI greater than 35 could not be palpated with a clear intervertebral space