What are the guidelines for managing obstructed labour?

Management of Obstructed Labour: Guidelines and Recommendations

The management of obstructed labour requires prompt recognition and intervention with a clear algorithmic approach, prioritizing cesarean delivery when appropriate to prevent maternal and fetal morbidity and mortality.

Definition and Recognition

• Obstructed labour occurs when the presenting part of the fetus cannot progress through the birth canal despite adequate uterine contractions, often due to mechanical obstruction 1
• Early recognition is critical through monitoring of labour progress, with active phase arrest defined as no cervical change despite adequate uterine contractions (≥200 Montevideo units) with normal fetal heart rate tracing 2, 3
• Signs of obstructed labour include prolonged labour, lack of descent of the presenting part, and formation of a pathological retraction ring 1

Initial Management Approach

• Assess for cephalopelvic disproportion (CPD), which occurs in 25-30% of active phase arrest cases, before proceeding with augmentation 2, 4
• For active phase arrest without evidence of CPD, oxytocin augmentation should be the first-line treatment with a reported success rate of 92% for vaginal delivery 2
• Oxytocin should be administered via intravenous infusion with accurate control of flow rate, starting at 1-2 mU/min and gradually increasing in increments of 1-2 mU/min until establishing a normal labour contraction pattern 5
• Continuous monitoring of fetal heart rate, uterine tone, and contraction pattern is essential during oxytocin administration 5

Duration of Augmentation

• Extend the minimum period of oxytocin augmentation for active-phase labour arrest to at least 4 hours before considering cesarean delivery, as this approach has been shown to be both effective and safe 6
• If no progress occurs after 4 hours of adequate oxytocin augmentation (>200 Montevideo units), reassess for CPD and consider cesarean delivery 2, 4
• For nulliparous women with no progress after 4 hours of oxytocin augmentation, the subsequent vaginal delivery rate is approximately 56%, while for parous women it is 88% 6

Anesthetic Considerations

• Consider early insertion of a neuraxial catheter for anticipated difficult delivery to reduce the need for general anesthesia if an emergent procedure becomes necessary 7
• Use dilute concentrations of local anesthetics with opioids for neuraxial analgesia to produce minimal motor block 7
• For cesarean delivery, neuraxial techniques are preferred over general anesthesia when possible 7
• If general anesthesia is required, ensure proper aspiration prophylaxis with timely administration of non-particulate antacids, H2-receptor antagonists, and/or metoclopramide 7, 8

Management of Impacted Fetal Head

• For cases with impacted fetal head during cesarean delivery, reverse breech extraction may be associated with better neonatal outcomes, including improved Apgar scores and reduced NICU admissions 7
• Avoid using a single forceps as a lever to disimpact the head or vacuum at cesarean delivery, as these techniques can cause significant fetal injury 7
• Ensure clinicians are familiar with disimpaction techniques to minimize complications 7

Special Considerations

• For patients with skeletal dysplasia, consider anatomical differences that may affect anesthesia administration and adjust fluid management according to the patient's size 7
• In cases of obstructed labour with fetal death, cesarean delivery remains the preferred option in most settings, though symphysiotomy may be considered in resource-limited settings 9
• Symphysiotomy shows no significant difference in maternal or perinatal mortality compared to cesarean section but has an increased risk of fistulae and stress incontinence 9

Emergency Preparedness

• Ensure immediate availability of basic and advanced life-support equipment in the labour and delivery unit 7
• In case of cardiac arrest during labour, maintain uterine displacement (usually left displacement) and if maternal circulation is not restored within 4 minutes, perform cesarean delivery 7
• Equipment for management of airway emergencies should be readily available, including pulse oximeter, qualitative carbon dioxide detector, and difficult airway equipment 7

Common Pitfalls and Caveats

• Delaying intervention in obstructed labour can lead to maternal complications including infection, obstetric fistulas, and uterine rupture 1
• Oxytocin infusion should be discontinued immediately in the event of uterine hyperactivity or fetal distress 5
• Failure to recognize the need for specialized equipment and personnel for difficult airway management can lead to adverse outcomes 8
• Underestimating the physiological changes of pregnancy can complicate airway management during emergency cesarean delivery 8