Effect of Co-administration of Carbetocin and Calcium Chloride on Uterine Tone in Patients Undergoing Elective Cesarean Delivery

Exclusion Criteria

• •1. Risk factors for uterine atony including:
• •1. Overdistended uterus due to fetal macrosomia reported on prenatal ultrasound \>90th centile or \> 4000 gm, multiple gestation, grand multiparity (≥5 births at ≥ 20 weeks gestation), polyhydramnios
• •2. History of uterine atony/PPH (documented with blood loss \> 2000 ml, blood transfusion, use of surgical methods such as Bakri balloon, B-Lynch sutures, uterine artery ligation or embolization)
• •3. Obesity with body mass index (BMI) \> 40 kg/m2
• •4. Placenta previa and/or placenta accreta
• •2. Digoxin therapy within 14 days (hypercalcemia can exacerbate digoxin toxicity)
• •3. Patients needing intraoperative IV ceftriaxone or tetracycline.
• •4. Kidney disease including Stage 3 chronic kidney disease, serum creatinine above 120 mmol/L or GFR \<60 ml/min (to prevent hypercalcemia due to reduced creatinine clearance in those with impaired kidney function as calcium is renally excreted)
• •5. Calcium channel blockade within 24 hours (opposing effect)
• •6. Known history of cardiac disease including arrhythmias, ischemia, and congenital heart disease (to avoid attributing cardiac symptoms to study drugs)
• •7. Preexisting hypertension, preeclampsia or persistent elevated blood pressure above 160/100 mmHg requiring treatment
• •8. Emergency cesarean deliveries or women in labor
• •9. Planned general anesthetic for patients where neuraxial is contraindicated.