Effect of Different Injection Speeds for Spinal Anaesthesia in Caesarean Section

Injection Speed of Spinal Anaesthesia for Asian Women Undergoing Lower Segmental Caesarean Section and the Incidence of Hypotension and/or Use of Vasopressors

The purpose of this study is to investigate if prolonging the speed of injection during spinal anaesthesia can reduce the incidence of hypotension and/or medication requirements thereby making it safer for the mother and foetus.

We plan to investigate if by varying the speed of injection during spinal anaesthesia, will there be a difference in the incidence of hypotension. Hypotension is a common complication especially for pregnant women undergoing caesarean section. A high speed of injection can theoretically cause a higher spread of anaesthetic, which may increase the incidence of hypotension. We want to know if by prolonging the injection time, will this lead to a reduction in a rate of hypotension.

Inclusion Criteria:

• at least 18 years of age
• singleton term pregnancy
• American Society of Anesthesiologists (ASA) class I-II

Exclusion Criteria:

• Severe pre-eclampsia
• contraindications to spinal anaesthesia
• Height <150cm or >180cm
• Weight ≥100kg
• Baseline systolic BP <90 mmHg
• Baseline systolic BP >150mmHg
• Category 1 urgency for delivery