How to manage uterine atony during cesarean section (CS)?

Management of Uterine Atony During Cesarean Section

Begin with immediate bimanual uterine massage while simultaneously administering oxytocin as the first-line uterotonic agent, then escalate through a stepwise protocol of additional uterotonics, mechanical interventions, and surgical procedures if bleeding persists. 1, 2

Immediate First-Line Management

Uterine Massage

• Perform bimanual uterine massage immediately upon recognition of atony to mechanically stimulate contractions 1
• This should be initiated simultaneously with pharmacologic management, not as a sequential step 1

Oxytocin Administration (First-Line Uterotonic)

• Administer 10-40 units of oxytocin added to 1,000 mL of non-hydrating diluent via IV infusion at a rate necessary to control atony 3
• Alternatively, give 10 units intramuscularly after placental delivery 3
• Oxytocin is the uterotonic of choice for both prophylaxis and treatment of uterine atony 2, 4
• Avoid bolus administration; use continuous infusion to minimize cardiovascular side effects (hypotension, tachycardia) 5
• Advanced maternal age (≥35 years) may require higher oxytocin doses, with ED50 approximately double that of younger patients 6

Second-Line Pharmacologic Management

Methylergonovine

• Administer 0.2 mg intramuscularly if oxytocin fails to achieve adequate uterine tone 7
• Absolutely contraindicated in hypertensive patients due to severe vasoconstriction risk 1, 2
• Also contraindicated in patients with respiratory disease (asthma, bronchiectasis) due to bronchospasm risk 8, 2

Carboprost Tromethamine (15-Methyl PGF2α)

• Use 250 mcg intramuscularly for refractory uterine atony that has not responded to oxytocin 9
• Can repeat every 15-90 minutes up to a maximum of 8 doses 9
• Contraindicated in patients with asthma due to bronchoconstriction 2
• Prior treatment with oxytocin should be documented before carboprost use 9

Tranexamic Acid

• Administer 1 gram IV within 1-3 hours of bleeding onset for massive hemorrhage 1, 2
• This antifibrinolytic agent reduces mortality from bleeding when given early 2

Mechanical/Tamponade Interventions

Intrauterine Balloon Tamponade

• Insert intrauterine balloon or uterine packing for refractory atony not responding to uterotonics 1
• This provides direct mechanical compression to control bleeding 1
• Should be attempted before proceeding to surgical interventions in hemodynamically stable patients 1

Surgical Interventions (Refractory Cases)

Conservative Surgical Options

• B-Lynch compression suture: Highly effective technique with 95.3% success rate in avoiding hysterectomy 10
• Bilateral uterine artery ligation: Can be performed alone or in combination with compression sutures 1, 10
• These fertility-sparing procedures should be attempted before hysterectomy 1, 10

Uterine Artery Embolization

• Consider in hemodynamically stable patients who have failed medical management and non-surgical interventions 1
• Requires interventional radiology availability and patient stability for transport 1

Hysterectomy

• Reserved for extreme cases when all other measures have failed 1
• This is the definitive treatment but results in loss of fertility 1

Critical Concurrent Management

Hemorrhage Protocol

• Implement massive transfusion protocol early with blood products at 1:1:1 ratio (packed red cells:fresh frozen plasma:platelets) 1
• Establish large-bore IV access immediately 1
• Monitor for and treat coagulopathy, which commonly develops following cardiovascular collapse or massive transfusion 1

Diagnostic Evaluation

• Thoroughly inspect the cervix and vagina to rule out lacerations that may be contributing to bleeding 1
• This is a critical step as bleeding may be multifactorial, and atony may coexist with surgical trauma 1

Surgical Technique Considerations to Prevent Atony

Intraoperative Prophylaxis

• Use blunt expansion (not sharp incision) of the transverse uterine hysterotomy to reduce surgical blood loss 8
• Close the hysterotomy in 2 layers, which may reduce future uterine rupture risk 8
• Administer prophylactic oxytocin 5-10 IU via slow IV or IM at time of shoulder delivery or immediately postpartum 2

Common Pitfalls to Avoid

• Never use methylergonovine in hypertensive patients—this can cause life-threatening hypertensive crisis 1, 2
• Avoid ergometrine and prostaglandin F2α in patients with respiratory disease (asthma, CF, bronchiectasis) due to bronchospasm risk 8, 2
• Do not delay escalation of therapy—move quickly through the treatment algorithm if bleeding continues 1
• Do not misdiagnose amniotic fluid embolism based solely on persistent atony with secondary coagulopathy 1
• Avoid rapid oxytocin bolus administration, which causes severe hypotension; use continuous infusion instead 5
• Do not overlook cervical or vaginal lacerations as concurrent sources of bleeding 1