This study compares the incidence of pruritus (itching) requiring treatment between two doses of intrathecal morphine (0.1 mg vs 0.2 mg) when used for spinal anesthesia during cesarean section. The study aims to determine if the lower dose (0.1 mg) can reduce pruritus incidence while maintaining adequate pain relief.

Spinal anesthesia is a standard technique for cesarean section. Intrathecal morphine (ITM) provides prolonged and effective analgesia but may cause adverse events including pruritus, nausea, vomiting, and respiratory depression. Current practice at Srinagarind Hospital uses ITM 0.2 mg for spinal anesthesia in cesarean section. This study investigates whether reducing the ITM dose to 0.1 mg can decrease pruritus incidence while preserving analgesic effectiveness.

Inclusion Criteria: • Pregnant women aged 18-45 years

• Full-term pregnancy
• Scheduled for non-emergency cesarean section
• ASA physical status I-III
• Non-complicated pregnancy

Exclusion Criteria:

• Contraindication to spinal anesthesia or study drugs
• Refusal to participate in the study
• BMI ≥ 40 kg/m²
• History of systemic skin disease or current itchy skin condition
• Use of antihistamines or anti-pruritic medications within 3 days prior to surgery

Pregnant female undergoing cesarean section

They are unaware of type of drug administered.