What are the recommendations for general anesthesia in women at risk of preterm birth?

General Anesthesia Management in Women at Risk of Preterm Birth

For women at risk of preterm birth requiring general anesthesia, comprehensive multidisciplinary planning involving anesthesiologists and high-risk obstetrical teams is essential to minimize maternal and fetal morbidity and mortality. 1

Preoperative Assessment and Planning

• Women with anticipated airway difficulties should be identified during antenatal care and referred for specific anesthetic and obstetric management planning 1
• A thorough airway assessment should document Mallampati grade, neck movement, mouth opening, thyromental distance, and jaw protrusion to predict potential difficulties with tracheal intubation, mask ventilation, or supraglottic airway device insertion 1
• Antenatal planning should consider equipment and personnel available for safe airway management, especially during out-of-hours emergencies 1
• For women at risk of preterm labor, early consultation with anesthesia is critical to develop contingency plans for emergency delivery 1

Anesthetic Technique Selection

• Neuraxial anesthesia (epidural or spinal) is strongly preferred over general anesthesia for cesarean delivery in women at risk of preterm birth 2
• General anesthesia should be reserved for situations where neuraxial techniques are contraindicated or in extreme emergencies 2
• When general anesthesia is required, careful attention must be paid to attenuating the hypertensive response to intubation 3
• If significant airway difficulties are predicted, awake tracheal intubation should be considered rather than rapid sequence induction 1

Specific Considerations for Preterm Birth Risk

• For women receiving tocolytic therapy (particularly beta-2 agonists or magnesium sulfate), be aware of potential drug interactions with anesthetic agents 4
• Magnesium sulfate can potentiate neuromuscular blocking agents, requiring dose adjustments and careful monitoring 4
• The volume of distribution for fluids and medications may need adjustment based on the patient's size and physiological status 1
• Continuous epidural analgesia initiated early in labor provides optimal flexibility for both vaginal delivery and potential emergency cesarean section 4

Airway Management

• Rapid sequence induction remains the standard technique when general anesthesia is required for cesarean delivery 1
• Proper positioning is crucial - the "ramped" position optimizes laryngoscopic view in pregnant patients 1
• Have difficult airway equipment immediately available, including video laryngoscopes and supraglottic airway devices 1
• Front-of-neck access equipment should be prepared in case of "can't intubate, can't oxygenate" scenario 1

Fasting and Aspiration Prophylaxis

• Women at high risk for preterm delivery should follow more restrictive oral intake guidelines - clear fluids only, no solid food 1
• H2-receptor antagonists should be administered every 6 hours during labor for women at high risk of requiring general anesthesia 1
• For emergency cesarean delivery, administer sodium citrate immediately before induction 1
• If general anesthesia is required, an H2-receptor antagonist should be given intravenously if not already administered 1

Team Communication and Planning

• Before induction of anesthesia, the anesthesiologist should discuss with the obstetric team whether to wake the woman or continue anesthesia in the event of failed tracheal intubation 1
• The World Health Organization surgical checklist should be used before each procedure, often modified locally for cesarean section 1
• A clear procedure for contacting a second anesthesiologist should be established, and induction delayed if appropriate while awaiting their attendance 1
• Intrauterine fetal resuscitation should be employed as appropriate before emergency operative delivery 1

Maternal and Fetal Monitoring

• Continuous monitoring of maternal vital signs including arterial pressure, ECG, and oxygen saturation is essential 3
• Perianesthetic recording of the fetal heart rate reduces fetal and neonatal complications 1
• For high-risk cases, invasive hemodynamic monitoring may be warranted 3
• Careful attention to maternal blood pressure is critical, as hypotension can compromise uteroplacental perfusion 5

Common Pitfalls and Caveats

• Spinal anesthesia has been associated with increased risk of neonatal mortality in very preterm infants compared to general anesthesia in some studies, possibly due to maternal hemodynamic instability 5
• Failure to recognize the need for specialized equipment and personnel for difficult airway management can lead to adverse outcomes 1
• Underestimating the physiological changes of pregnancy can complicate airway management 1
• Delaying anesthesia consultation until an emergency arises limits options and increases risks 1

By following these recommendations and maintaining a high index of suspicion for potential complications, anesthesiologists can optimize outcomes for both mother and baby when general anesthesia is required in women at risk of preterm birth.