BACKGROUND AND PURPOSE: 

• There is conflicting data as to whether oxytocin can reduce bleeding during myomectomy  
• Atashkhoei et al. (BJOG, 2018) sought to determine the effectiveness and safety of oxytocin for reducing blood loss in abdominal myomectomy

METHODS: 

• Double-blind randomized controlled trial (RCT) 
  • Participants: Otherwise healthy women who were candidates for abdominal myomectomy 
    • No prior GnRh analogues 
    • No submucous fibroids  
• Women received either 
  • Oxytocin 30 IU in 500 ml normal saline at a rate of 120 ml/hour starting during myomectomy procedure  
  • Placebo of normal saline 
• Primary outcome: Intraoperative blood loss (ml)  
  • Calculated by: sum of canisters containing irrigation fluids and suctioned blood minus used irrigation solution plus the amount of absorbed blood in used sponges 
• Secondary outcomes 
  • Transfusion | Vitals | Hemoglobin and hematocrit | Time to ambulation | Other relevant clinical outcomes  
• Statistics 
  • To detect a difference of 200 ml in blood loss, approximately y40 patients were required in each group 
  • Power of 0.9 and level of significance of 0.05

RESULTS: 

• 40 in study (oxytocin) group | 40 in placebo group   
• Uterine size (P=0.74) 
  • Study group: 14.8±0.25 weeks
  • Placebo group: 15.05±0.62 weeks
• Estimated intra-operative blood loss was significantly lower in the study group  
  • Study group: 189.5±16.72 (SD) mL 
  • Placebo group: 692.25±89.93 mL 
  • 95% CI, 672.54 to 711.96 mL (P<0.0001) 
• Blood transfusions were significantly less frequent in the study group  
  • Three (7.5%) women in the study group 
  • 10 (25%) women in the placebo group 
  • 95% CI 15.5-34.5 (P<0.001) 
• Differences also seen in the following outcomes  
  • Duration of surgery (P=0.01) and anesthesia (P=0.02) 
  • Time to ambulation (P=0.03)  
  • Hospitalization time (P<0.0001) 
• No major side effects identified in either group

CONCLUSION: 

• Intra-operative oxytocin infusion reduced blood loss and need for transfusion during abdominal myomectomy 
• Consistent with literature of approximately 20% of women requiring blood transfusion during abdominal hysterectomy 
  • In this study, 25% of placebo group and 7.5% in blood transfusion group required transfusion  
• Limitations include 
  • Investigators did not weigh fibroid mass  
  • Minimally invasive surgery is becoming the surgery of choice for fibroids, even when large

Learn More – Primary Sources: 

Effect of oxytocin infusion on reducing the blood loss during abdominal myomectomy: a double-blind randomised controlled trial

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