Anesthesia for nondelivery obstetric procedures

INTRODUCTION — Nondelivery obstetric-related procedures, including cerclage, external cephalic version (ECV), and postpartum tubal ligation (PPTL), may be necessary during pregnancy or in the early postpartum period. This topic will discuss anesthetic management for these procedures.

Obstetric management of cervical incompetence, and obstetric issues related to ECV and PPTL are discussed separately. (See "Cervical insufficiency" and "External cephalic version" and "Postpartum permanent contraception: Procedures".)

Anesthesia for nonobstetric surgery during pregnancy is also discussed separately. (See "Anesthesia for nonobstetric surgery during pregnancy", section on 'Management of anesthesia'.)

PREANESTHESIA EVALUATION — A medical and obstetric history and anesthesia-directed physical examination, including airway assessment, should be performed for all pregnant patients who undergo any type of anesthesia. When considering neuraxial anesthesia, the assessment should include a focus on medical conditions that may alter the physiologic response to neuraxial anesthesia or increase the risk of complications (eg, coagulopathy, systemic and local infection, spine abnormalities, neurologic disease). (See "Overview of neuraxial anesthesia", section on 'Preoperative evaluation' and "Airway management for induction of general anesthesia", section on 'Airway assessment'.)

Laboratory evaluation — In anticipation of neuraxial anesthesia, we review prenatal laboratory results, and order further testing selectively, as follows:

●Cerclage – Testing according to comorbidities (eg, complete blood count [CBC] if there is a history of thrombocytopenia).

●External cephalic version – Laboratory testing is the same as for cesarean delivery, in case cesarean delivery is planned or emergency cesarean delivery becomes necessary. (See "Cesarean birth: Preoperative planning and patient preparation", section on 'Laboratory testing'.)

●Postpartum tubal ligation – Testing based on patient factors and blood loss at delivery (eg, CBC if postpartum hemorrhage occurred or if thrombocytopenia is a concern due to preeclampsia).

PREPARATION FOR ANESTHESIA — Preparation for anesthesia includes placement of an intravenous (IV) catheter and standard physiologic monitors, measures to prevent pulmonary aspiration, and in some cases, premedication.

●Preoperative fasting – Preoperative fasting for pregnant patients is similar to nonpregnant patients (ie, two hours for clear liquids, six hours for a light meal, and eight hours after a heavy meal) [1]. (See "Preoperative fasting in adults", section on 'Pregnant patients'.)

●Pharmacologic aspiration prophylaxis – Pregnant patients may be at increased risk of aspiration during induction of (or emergence from) general anesthesia, especially in cases of difficult or failed intubation when mask ventilation may be required. However, the incidence of aspiration is low, and the need for pharmacologic prophylaxis for aspiration should be assessed on an individual basis depending on patient- and anesthesia-related factors. This issue is discussed separately. (See "Anesthesia for nonobstetric surgery during pregnancy", section on 'Preoperative aspiration mitigation'.)

Pregnant patients at term have a high incidence of symptomatic gastroesophageal reflux disease (GERD), which may increase the risk of aspiration. (See "Maternal adaptations to pregnancy: Gastrointestinal tract", section on 'Gastroesophageal reflux'.)

The authors administer preoperative prophylaxis for patients with symptomatic GERD, and for pregnant patients for whom general anesthesia is planned beyond 18 weeks of pregnancy (this needs to be evaluated on an individual basis). For prophylaxis we administer a gastrointestinal prokinetic agent (eg, metoclopramide 10 mg IV bolus 60 minutes prior to induction of anesthesia), a histamine-2 receptor blocker (eg, famotidine 20 mg IV 60 to 90 minutes prior to induction or 20 mg orally the night prior to surgery and again the morning of surgery), and nonparticulate antacid (eg, sodium citrate-citric acid 30 mL orally just prior to induction). Others administer aspiration prophylaxis for all pregnant patients beyond 18 to 20 weeks gestation, regardless of the type of anesthesia used.

●Premedication – Sedative premedication is not usually required or indicated prior to nonobstetric procedures. If anxiolysis is required, small doses of a sedative should be titrated to effect (eg, midazolam 0.5 mg IV, repeated as necessary).

AIRWAY CONCERNS — In most cases in which neuraxial or general anesthesia are possible in pregnant patients, particularly later in pregnancy, neuraxial anesthesia is preferred, primarily to avoid the need for airway management. For general anesthesia, the plan for airway management must take into account not only pregnancy, but also assessment of the other risk factors for difficulty with airway management. (See "Management of the difficult airway for general anesthesia in adults".)

The reported incidence of failed intubation is much higher in obstetric patients (see "Airway management for the pregnant patient", section on 'Incidence and consequences of airway problems'). In addition, the consequences of difficulty with airway management (ie, hypoxemia, hypercarbia, cardiac compromise) are greater in pregnant patients and their fetuses. Desaturation occurs more rapidly during apnea with increasing oxygen consumption and decreasing functional residual capacity as pregnancy progresses.

Difficulty with airway management may increase over the course of pregnancy, as weight gain and upper airway edema occur. As an example, in one study of airway assessment during pregnancy, the incidence of Mallampati grade 4 airway assessments increased by 34 percent between 12 and 38 weeks gestation [2]. (See "Maternal adaptations to pregnancy: Dyspnea and other physiologic respiratory changes", section on 'Physiologic pulmonary changes in pregnancy'.)

CERVICAL CERCLAGE — Cervical cerclage is a procedure performed to decrease the incidence of preterm delivery in women who have cervical insufficiency (see "Transvaginal cervical cerclage"). The procedure can either be performed on an elective basis in women who have a history of cervical insufficiency, or on an urgent basis for patients with cervical insufficiency found by ultrasound or on physical examination. (See "Transvaginal cervical cerclage", section on 'Goal' and "Cervical insufficiency", section on 'Cerclage placement and use of progesterone supplementation'.)

Timing of cerclage — The timing of cerclage during pregnancy determines the extent of the physiologic changes of pregnancy that may affect anesthetic care. Elective transvaginal history-indicated cerclages are usually performed between 12 and 14 weeks of gestation. At this stage of pregnancy, airway edema and weight gain are usually minimal and left uterine displacement is not typically necessary. However, ultrasound-indicated and physical exam-indicated cerclage is performed up to 23 weeks of gestation, at a stage of pregnancy in which physiologic changes are of more concern. Transabdominal and laparoscopic cerclage may be performed preconception, or in the late first trimester to early second trimester of pregnancy. (See "Transabdominal and laparoscopic cervicoisthmic cerclage", section on 'Issues with preconception placement' and "Transabdominal and laparoscopic cervicoisthmic cerclage", section on 'Issues with placement during pregnancy'.)

Transvaginal cerclage

Tocolytics — Indomethacin (nonsteroidal anti-inflammatory drug [NSAID]) may be administered for prophylactic tocolysis. NSAIDs can be used in patients who receive neuraxial anesthesia, without an increase in risk of spinal or epidural hematoma. (See "Neuraxial anesthesia/analgesia techniques in the patient receiving anticoagulant or antiplatelet medication", section on 'Aspirin and other nonsteroidal antiinflammatory drugs' and "Transvaginal cervical cerclage", section on 'Prophylactic pharmacotherapy'.)

Fetal heart rate monitoring — At a minimum, the fetal heart rate should be documented pre- and postoperatively, regardless of gestational age. For viable fetuses (greater than 23 to 24 weeks of gestation), continuous fetal heart rate monitoring during the procedure should be individualized and discussed with the obstetrician and patient before the procedure. This issue is discussed separately. (See "Nonobstetric surgery in pregnant patients: Patient counseling, surgical considerations, and obstetric management", section on 'Fetal heart rate monitoring'.)

Choice of anesthetic technique — Transvaginal cerclage can be performed with neuraxial or general anesthesia. The choice of anesthetic technique should be based on patient factors and patient choice. For patients who undergo cerclage in whom either general anesthesia or neuraxial anesthesia would be appropriate, we suggest neuraxial anesthesia, and prefer single-shot spinal or combined spinal-epidural (CSE) if the procedure is expected to take longer than usual.

Neuraxial anesthesia avoids the need to manage the patient's airway, minimizes fetal exposure to anesthetic drugs, and is associated with less nausea and vomiting and sedation than general anesthesia. Time for block regression may delay discharge compared with general anesthesia.

Single-shot spinal and combined spinal-epidural anesthesia — Sensory blockade to T8 to T10 is necessary for transvaginal cerclage to anesthetize the cervix (T10 to L1) and the vagina (S2 to S4). Our usual single-shot spinal drug combination includes 7.5 mg bupivacaine (1 mL of 0.75% hyperbaric bupivacaine or 1.5 mL of 0.5% isobaric bupivacaine) plus fentanyl 15 mcg intrathecally. For procedures that are expected to be longer, we increase the dose of bupivacaine to 9 to 10.5 mg (eg, 1.2 to 1.4 mL of 0.75% hyperbaric bupivacaine) or insert an epidural catheter for possible extension of the block (ie, perform a CSE).

If neuraxial anesthesia is used for a patient with a dilated cervix or bulging membranes, we position the patient in the lateral decubitus position rather than sitting to perform the neuraxial procedure, and maintain Trendelenburg position throughout to minimize gravitational pressure on the cervix. If the patient is in a very steep Trendelenburg position and there is concern for a high block, isobaric (plain) bupivacaine is an option in this setting. (See "Spinal anesthesia: Technique", section on 'Positioning for spinal procedure' and "Spinal anesthesia: Technique", section on 'Baricity' and 'Positioning' below.)

General anesthesia — The principles for management of general anesthesia for transvaginal cerclage are similar to those that are used for cesarean delivery (see "Anesthesia for cesarean delivery"). The appropriate strategy for airway management may depend on the gestational age at the time of the procedure, with increasing risk of passive regurgitation (and aspiration during anesthesia) as pregnancy progresses. For patients whose pregnancy is ≥18 weeks gestational age, or who have symptoms of gastroesophageal reflux disease (GERD), we perform rapid sequence induction and intubation for general anesthesia. For patients <18 weeks gestational age, without symptoms of GERD, we place a supraglottic airway (SGA) for airway management. (See "Airway management for the pregnant patient", section on 'Choice of airway devices' and "Airway management for the pregnant patient", section on 'RSII versus routine intubation'.)

General anesthesia with volatile inhalation agents may be used to provide uterine relaxation and allow replacement of bulging membranes. Alternatively, nitroglycerin (50 to 200 mcg intravenous [IV]) can be administered to relax the uterus during general or neuraxial anesthesia, if indicated.

Positioning — The patient is positioned in lithotomy, with left uterine displacement if >20 weeks gestation (or earlier gestation if evidence of supine hypotension). The operating table may be positioned head down (ie, Trendelenburg) to optimize surgical access, and may be tipped steeply down to facilitate replacement of prolapsed fetal membranes. (See "Transvaginal cervical cerclage", section on 'Replace prolapsed membranes, if present'.)

Hemodynamic management — Blood pressure goals and the use of vasopressors in pregnancy have generally been studied in women undergoing cesarean delivery; these goals for physiologic parameters are also applicable for women having other types of surgery during pregnancy.

We aim to maintain the patient's baseline blood pressure throughout the procedure with administration of vasopressor boluses as required. A prophylactic phenylephrine infusion, which is usually administered during neuraxial anesthesia for cesarean delivery, is not routinely required for patients who are not at or near term in pregnancy. In patients who become symptomatic with nausea, vomiting, or lightheadedness, or if the fetus shows signs of distress on fetal heart rate monitoring, hypotension should be evaluated as the primary etiology. (See "Anesthesia for cesarean delivery", section on 'Hemodynamic management'.)

Postoperative analgesia — Postoperative pain is usually mild after cerclage, and is usually effectively managed with oral acetaminophen. We avoid administration of NSAIDs during pregnancy because of potential fetal effects, as well as the risk of premature closure of the ductus arteriosus in advanced gestation [3,4]. (See "Prenatal care: Patient education, health promotion, and safety of commonly used drugs", section on 'NSAIDs' and "Safety of rheumatic disease medication use during pregnancy and lactation", section on 'NSAIDs'.)

Transabdominal cerclage — Transabdominal cerclage may be performed for patients with a prior pregnancy loss despite a prior transvaginal cerclage and/or those who are unable to undergo a transvaginal cerclage. The procedure may be performed preconception, or after conception during the late first trimester or early second trimester, once fetal viability has been established. (See "Transabdominal and laparoscopic cervicoisthmic cerclage".)

Transabdominal cerclage may be performed via laparotomy or laparoscopy. The majority of these cases are performed as day-cases.

Choice of anesthetic technique — The choice of anesthetic technique for transabdominal cerclage should be based on patient factors and patient preference, with the aim of reducing fetal drug exposure if the patient is pregnant. Open procedures can be performed with neuraxial (single-shot spinal, epidural, or CSE) or general anesthesia. Laparoscopic procedures require general anesthesia.

For neuraxial anesthesia, we prefer a single-shot spinal or CSE, rather than epidural anesthesia. Compared with epidural, single-shot spinal anesthesia provides rapid onset of dense, bilateral, reliable anesthesia, using a very low dose of drug with minimal risk of maternal toxicity or fetal drug transfer. A CSE allows extension of the anesthetic with the epidural catheter if necessary.

Anesthetic management — For pregnant patients, the principles for anesthetic management for transabdominal cerclage are similar to those that are used for transvaginal cerclage. (See 'Choice of anesthetic technique' above.)

General anesthesia can be performed with an endotracheal tube or SGA. (See 'General anesthesia' above.)

For preconception procedures, an intrathecal dose of 15 mg bupivacaine (2 mL 0.75% hyperbaric bupivacaine or 3 mL 0.5% isobaric bupivacaine) plus fentanyl 15 mcg intrathecally is adequate. For procedures during pregnancy, 12 mg bupivacaine (1.6 mL 0.75% hyperbaric bupivacaine or 2.4 mL 0.5% isobaric bupivacaine) plus fentanyl 15 mcg intrathecally is adequate. A lower dose of bupivacaine is administered during pregnancy (versus preconception) as the gravid uterus enhances cephalad spread of intrathecal medications [5]. A prophylactic phenylephrine infusion is not routinely required for patients who are not pregnant or who are early in pregnancy.

Postoperative analgesia — For all surgical procedures, the optimal strategy for perioperative pain control consists of multimodal therapy to minimize the need for opioids.

●For laparoscopic procedures, postoperative pain can usually be managed with local anesthetic (LA) infiltration of the port incisions, regularly scheduled nonopioid analgesics (acetaminophen), and oral opioids as necessary. (See "Anesthesia for laparoscopic and abdominal robotic surgery in adults", section on 'Postoperative pain management'.)

●For laparotomy, options for pain control are similar to those that are used after cesarean delivery, and may include oral nonopioid analgesics (acetaminophen), regional anesthesia techniques (eg, transversus abdominis plane block, quadratus lumborum block), and oral opioids as necessary. For patients who are admitted to the hospital postoperatively, intrathecal opioids are another option (eg, morphine 150 mcg) if spinal or CSE anesthesia is used. (See "Post-cesarean delivery analgesia".)

Anesthesia for removal of cerclage — Transvaginal cerclages are removed at 37 weeks gestation or immediately upon onset of premature labor. A McDonald cerclage usually can be cut and removed in the office without analgesia. A Shirodkar cerclage often requires a return to the operating room for removal, either because the knot is buried under the vaginal epithelium or the Mersilene tape has been infiltrated by cervical granulation tissue.

For patients who require anesthesia for cerclage removal, the procedure may be performed with light sedation (eg, midazolam 1 to 2 mg IV and/or fentanyl 50 to 100 mcg IV) or with inhalation analgesia with 50 percent nitrous oxide with oxygen.

If the suture removal is particularly difficult, anesthetic management would be similar to management for cerclage placement, with a single-shot spinal preferred (see 'Single-shot spinal and combined spinal-epidural anesthesia' above). If the patient is in spontaneous labor (or the plan is to induce labor during the same hospital admission), a CSE technique can be considered, with the spinal component used for the suture removal, and activation of the epidural catheter when necessary for labor analgesia.

Patients who have undergone transabdominal cerclage usually have a planned cesarean delivery. The cerclage may be removed at the time of cesarean delivery, or left in place for future pregnancies. Decisions regarding removal of transabdominally placed cerclage are discussed separately. (See "Transabdominal and laparoscopic cervicoisthmic cerclage", section on 'Management of the cerclage after delivery'.)

EXTERNAL CEPHALIC VERSION — External cephalic version (ECV) is a procedure in which the fetus is rotated from a noncephalic to a cephalic presentation by manipulation through the mother's abdomen. It is typically performed as an elective procedure in non-laboring women at or near term to improve their chances of having a vaginal cephalic birth. The ECV procedure, including indications, timing, success rates and complications are discussed separately. (See "External cephalic version".)

Analgesia versus no analgesia — ECV is uncomfortable for the patient, but can be performed with or without analgesia/anesthesia. Some obstetricians and patients prefer to avoid analgesia for a first attempt at ECV, and administer analgesia only if necessary. (See "External cephalic version".)

Compared with intravenous [IV] or no analgesia, neuraxial analgesia/anesthesia (single-shot spinal, epidural, or combined spinal-epidural [CSE]) increases the likelihood of successful ECV. This is discussed in detail separately. (See "External cephalic version", section on 'Role of neuraxial anesthesia'.)

A 2023 meta-analysis of randomized trials suggests that remifentanil analgesia for ECV increases success rates [6]. Nitrous oxide has been used for analgesia during ECV, without statistically significant effects on ECV success rates compared with no analgesia [7].

Factors other than analgesia that affect the success of ECV are discussed separately. (See "External cephalic version", section on 'Outcomes'.)

Preparation and setting for ECV — Patients who undergo external cephalic version (ECV) are at a small risk of requiring emergency cesarean delivery. Therefore, in our practice, patients who undergo ECV with or without analgesia have a preanesthesia evaluation, follow preoperative fasting guidelines, and have an IV catheter placed before the procedure (see 'Preparation for anesthesia' above). However, practice varies and other UpToDate contributors do not routinely place an IV or ask patients to fast prior to ECV. (See "External cephalic version", section on 'Oral intake'.)

ECV with anesthesia/analgesia should be performed in the operating room with standard American Society of Anesthesiologists (ASA) monitoring. ECV without anesthesia/analgesia can be performed on the labor floor with an operating room and anesthesia personnel available if needed for immediate cesarean delivery.

The noncephalic presentation of the fetus is confirmed just prior to ECV. Tocolysis (eg, terbutaline) is typically administered prior to ECV to relax the uterus (see "External cephalic version", section on 'Tocolysis'). Fetal heart rate monitoring is used prior to, during (intermittently, as possible), and after ECV. (See "External cephalic version", section on 'Assessment of fetal well-being'.)

The plan for obstetric management after successful or unsuccessful ECV (eg, discharge to home for subsequent vaginal or cesarean delivery, induction of labor, immediate cesarean delivery) should be discussed with the obstetrician and patient, as this information may affect the doses of neuraxial anesthesia administered.

Choice of neuraxial technique — The choice of neuraxial technique should be based on patient factors, including the likelihood of successful version, the plan for management after the procedure, and the patient-specific risks associated with general anesthesia (ie, obesity, predicted difficult airway) if an emergency cesarean delivery is necessary. Spinal anesthesia can provide rapid effective analgesia/anesthesia to a T6 level for ECV, while epidural and CSE techniques allow extension of block to T4 for cesarean delivery, or continuation at a T10 level for labor analgesia, as indicated. The authors suggest CSE over an epidural technique due to quicker onset and block reliability, and prefer CSE over single-shot spinal due to ability to dose the epidural if needed for additional analgesia or anesthesia for cesarean delivery.

Neuraxial analgesia/anesthesia drug doses — We base neuraxial drug doses for ECV on the plan for obstetric management after the procedure (ie, discharge whether ECV successful or not, versus cesarean or vaginal delivery during same hospitalization), patient factors, and the likelihood of successful ECV. In general, we increase the dose of intrathecal local anesthetic (LA) for patients at higher risk of cesarean delivery, and/or higher risks associated with general anesthesia if it is required, and/or patients who will undergo cesarean delivery during the same hospitalization following unsuccessful ECV.

For the purpose of this approach, high-risk patients are defined as those with anesthetic risk factors (eg, obesity, risk factors for difficulty with airway management) and with high probability of requiring emergency cesarean birth (eg, a primiparous patient with a large fetus, or a patient with borderline amniotic fluid index). Low-risk patients are those without anesthetic risk factors, and with low or average probability of emergency cesarean birth.

The authors' approach to intrathecal drug doses for is as follows:

●Low-risk patients

•Plan for discharge whether ECV is successful or not – We use low doses of intrathecal LA to allow rapid resolution of the neuraxial block, as follows:

1 mL of 0.75% hyperbaric bupivacaine (7.5 mg); or 1.5 mL of 0.5% isobaric bupivacaine (7.5 mg) plus fentanyl 15 to 20 mcg or sufentanil 2.5 to 5 mcg

•Plan for vaginal birth during the same hospitalization if ECV is successful – We administer an intrathecal dose of LA that is likely to provide adequate anesthesia for ECV:

1 mL of 0.75% hyperbaric bupivacaine (7.5 mg); or 1.5 mL of 0.5% isobaric bupivacaine (7.5 mg) plus fentanyl 15 to 20 mcg or sufentanil 2.5 to 5 mcg

Supplemental doses of epidural LA (10 to 20 mL 2% lidocaine with epinephrine 1:200,000) will be required in the event of an emergency cesarean delivery

•Plan for cesarean birth during the same hospitalization if ECV is unsuccessful, discharge if ECV is successful – We administer an intrathecal dose of LA slightly less than the dose that would be used for elective cesarean birth to facilitate rapid discharge if ECV is successful, as follows:

10.5 mg bupivacaine (1.4 mL of 0.75% hyperbaric bupivacaine, or 2.1 mL of 0.5% isobaric bupivacaine), plus fentanyl 15 to 20 mcg or sufentanil 2.5 to 5 mcg

●High-risk patients – For high-risk patients, we administer a dose of intrathecal LA that is close to the full dose that would be used for cesarean birth, regardless of the plan for delivery or discharge. We accept the prolonged duration of neuraxial block that will be unnecessary if ECV is successful, in order to minimize the possible need for general anesthesia for emergency cesarean birth. We administer intrathecal medication as follows:

1.4 mL of 0.75% bupivacaine (10.5 mg), or 2.1 mL of 0.5% isobaric bupivacaine (10.5 mg), with fentanyl 15 to 20 mcg or sufentanil 2.5 to 5 mcg

The optimal single-shot spinal or epidural drug doses for ECV is not known, the need for surgical anesthesia rather than analgesia to improve success for ECV has not been determined, and data are conflicting. Subgroup analysis from a meta-analysis of randomized trials that compared neuraxial techniques with no neuraxial analgesia for ECV suggested that LA doses capable of producing a motor block (intrathecal bupivacaine 7.5 mg or epidural lidocaine 2% 10 to 15 mL to induce a sensory level of T6) were necessary to increase ECV success, rather than analgesic neuraxial doses [8]. In contrast, a randomized trial that compared four doses of intrathecal bupivacaine ranging from analgesic to anesthetic doses (2.5, 5.0, 7.5, and 10 mg) combined with intrathecal fentanyl 15 mcg for CSE for ECV reported no difference in the ECV success rate or cesarean delivery rate among groups [9].

Pain after ECV is usually mild and is managed effectively with oral acetaminophen.

Patient positioning for ECV — The patient is positioned supine with left uterine displacement.

Hemodynamic management — Hemodynamic management, including IV fluids, standard ASA monitoring, blood pressure goals, and administration of vasopressor boluses as required, should be performed to maintain maternal blood pressure parameters at baseline. The spinal doses discussed above rarely cause hypotension that requires a phenylephrine infusion. These issues are discussed separately. (See "Adverse effects of neuraxial analgesia and anesthesia for obstetrics", section on 'Hypotension' and "Anesthesia for cesarean delivery", section on 'Hemodynamic management'.)

POSTPARTUM TUBAL LIGATION — Postpartum tubal ligation (PPTL) for female sterilization can be performed during a cesarean delivery or as a surgical procedure after a vaginal delivery. PPTL after vaginal delivery, which is discussed here, is usually performed via an infraumbilical mini-laparotomy, and is typically performed within hours to days after delivery.

Preparation for anesthesia — A preanesthesia evaluation and consent for anesthesia should be performed after delivery for patients scheduled for PPTL (for epidural catheter reactivation, block replacement, or a primary neuraxial block). Assessment should include an estimate of blood loss at delivery, hemodynamic status, airway evaluation, and the status of pregnancy-related conditions (eg, preeclampsia). Excessive blood loss, hemodynamic instability, or infection may require delay of surgery. Timing of PPTL in patients with ongoing obstetric-related issues (ie, preeclampsia with severe features) should be individualized after discussion with the obstetric team.

All patients who undergo PPTL should be considered at risk for aspiration, particularly within 24 hours of delivery, as the gastrointestinal physiologic changes of pregnancy may still be present at the time of the procedure. Preoperative fasting, aspiration prophylaxis, and laboratory evaluation are discussed above. (See 'Preparation for anesthesia' above and 'Laboratory evaluation' above.)

Timing of postpartum tubal ligation — PPTL is considered an urgent procedure by the American College of Obstetrics and Gynecology [10]. In this setting, urgency is defined as the need to complete the procedure within the postpartum stay, without delaying discharge. Delays that result in discharge without the procedure can result in future unwanted pregnancy. Timing of PPTL is discussed separately. (See "Overview of female permanent contraception", section on 'Postpartum permanent contraception'.)

The optimal timing of tubal ligation after delivery is controversial, and practice varies [11]. Many clinicians favor waiting 6 to 24 hours after delivery so that adequate assessment of the neonatal health and postpartum complications, including maternal hemorrhage, can be made. This time frame allows major gastrointestinal physiologic changes of pregnancy to partially resolve to lessen the gastric aspiration risk associated with pregnancy. There are no data suggesting that risk is decreased by waiting for a specific interval, or that risk is increased by performing PPTL immediately after delivery. At the authors' institution, PPTL is performed on the day of delivery (including in some patients, immediately after delivery) or the next day.

The physiologic changes of pregnancy and labor and delivery resolve to a varying degree during the immediate postpartum period. Changes particularly relevant for anesthesia care resolve as follows:

●Airway swelling and edema related to pregnancy and labor and delivery can take longer than 48 hours to resolve. These issues are discussed separately. (See "Airway management for the pregnant patient" and "Airway management for the pregnant patient", section on 'Anatomic and physiologic changes of pregnancy'.)

●Functional residual capacity increases and oxygen consumption decreases significantly immediately after delivery, but takes a few weeks to return to pre-pregnancy physiologic baseline.

●Cardiac output increases markedly immediately after delivery, and then decreases to the pre-labor level at 24 hours postpartum [12]. Thereafter, cardiovascular physiologic changes of pregnancy resolve slowly and return to prepregnancy levels by 12 to 24 weeks postpartum [13]. (See "Maternal adaptations to pregnancy: Cardiovascular and hemodynamic changes", section on 'Postpartum changes'.)

●Pregnant and postpartum patients may be at increased risk of aspiration partly as a result of gastroesophageal reflux disease (GERD). Symptoms of GERD are the result of both mechanical and intrinsic factors that adversely affect lower esophageal sphincter pressure (see "Maternal adaptations to pregnancy: Gastrointestinal tract", section on 'Gastroesophageal reflux'). Some mechanical factors (eg, increased intra-abdominal pressure) resolve immediately after delivery, whereas lower esophageal sphincter tone resolves over the course of one to four weeks [14,15].

Pregnancy does not delay gastric emptying, however labor and parenteral/neuraxial opioids contribute to delayed gastric emptying, which returns to pre-pregnancy levels by 18 hours postpartum [16].

●The local anesthetic (LA) requirement for neuraxial anesthesia is reduced during pregnancy, and increases to a clinically significant degree within 24 hours of delivery [17-19]. Thus a dose of LA that would be adequate for spinal anesthesia for cesarean delivery may be inadequate for PPTL. Reasons for a rapid return to prepregnant LA sensitivity have not been determined, but may be related to the rapid fall in progesterone levels after delivery of the placenta [20].

For patients who require postpartum antithrombotic therapy, the timing for PPTL should be discussed with the obstetrician. PPTL may best be performed immediately after delivery for patients who require ongoing anticoagulation prophylaxis or treatment. (See "Use of anticoagulants during pregnancy and postpartum", section on 'Resuming or initiating anticoagulation postpartum'.)

Choice of anesthetic technique — The choice of anesthetic technique should be based on patient factors (eg, comorbidities, patient-specific risks of general anesthesia, patient preference), and the existence (or lack) of an in situ labor epidural catheter. For patients in whom either neuraxial anesthesia or general anesthesia would be appropriate, we suggest the use of neuraxial anesthesia for PPTL.

Patients with a labor epidural catheter in situ — For the patient with a labor epidural catheter in place, the epidural catheter can be reactivated to provide surgical anesthesia for PPTL. The reported rates of successful reactivation of labor epidural catheters vary, from approximately 75 percent to over 90 percent [11,21,22]. Successful reactivation of a labor epidural catheter is most likely if the time period between delivery and activation is short. However, successful reactivation is difficult to predict, and may also be affected by the quality of the labor analgesia it provided and the length of time the catheter was in place. We attempt reactivation of a labor epidural in the following circumstances:

●The epidural catheter worked well for labor analgesia without multiple clinician top-ups, and

●The epidural catheter does not appear to have migrated out of the epidural space (ie, the catheter marking at the skin indicates that an adequate length of epidural catheter is in the epidural space), and

●Reactivation is attempted within 24 hours of placement of the epidural catheter

The authors attempt to reactivate a labor epidural for PPTL as follows:

●Administer 10 mL of 2% lidocaine with epinephrine 1:200,000 (2 to 3 mL test dose, the remainder in two increments) via the epidural catheter.

●Assess the level of sensory block after 5 to 10 minutes.

•If there is evidence of a bilateral sensory block, administer an additional 5 to 10 mL 2% lidocaine with epinephrine 1:200,000, plus fentanyl 100 mcg via the epidural catheter, to achieve a bilateral T6 to T8 block.

•If there is evidence of a unilateral sensory block, withdraw the epidural catheter 1 to 2 cm before administering the additional epidural bolus.

•If there is no evidence of a sensory block, remove the epidural catheter, and perform an alternative neuraxial anesthesia technique (single-shot spinal or combined spinal-epidural [CSE]) or general anesthesia.

●Alternative neuraxial technique following inadequate epidural catheter reactivation (ie, unilateral, patchy, or no detectable block):

Remove the epidural catheter and administer a single-shot spinal or CSE at a reduced dose (ie, 1.0 to 1.2 mL of 0.75% hyperbaric bupivacaine plus fentanyl 15 to 20 mcg), a sequential CSE (ie, low dose spinal, completed with the epidural), or general anesthesia. The spinal level is somewhat unpredictable in the presence of any residual epidural block. Unlike anesthesia for cesarean delivery, in the postpartum patient the risk of high spinal is much lower with a single-shot spinal or CSE, as the cephalad spread of intrathecal medication is less after delivery. Prior to a cesarean delivery, a full dose spinal (eg, 1.6 mL of 0.75% hyperbaric bupivacaine) should not be administered after a failed neuraxial technique (with any evidence of a block), as a high or total spinal could result. This issue is discussed separately. (See "Anesthesia for cesarean delivery", section on 'Failed or inadequate neuraxial block'.)

Patients without an epidural catheter in place

●Single-shot spinal anesthesia – PPTL requires a spinal dermatomal level of T6 to T8 bilaterally. Spinal anesthesia usually provides surgical anesthesia adequate for the duration of PPTL. A CSE may be performed for patients with obesity, or if the surgery is expected to be technically challenging (eg, prior abdominal surgery), to allow extension of the block with the epidural catheter. There is limited literature regarding the optimal dose of LA for spinal anesthesia for PPTL, and practice varies. In the authors' experience, there is a higher failure rate of spinal anesthesia for PPTL compared with spinal anesthesia for cesarean delivery; reasons for this are unclear and may be multifactorial.

The authors perform single-shot spinal or CSE for PPTL with the following intrathecal medication, using an LA dose higher than would be used for cesarean delivery:

12 to 13.5 mg bupivacaine (1.6 to 1.8 mL of 0.75 percent hyperbaric bupivacaine, or 2.4 to 2.7 mL of 0.5 percent isobaric bupivacaine) plus fentanyl 15 to 20 mcg

●General anesthesia – We assume that patients who have PPTL soon after delivery are at increased risk of aspiration during general anesthesia, with the first 24 hours post-delivery generally considered the highest risk period. For patients who have general anesthesia for PPTL within 24 hours of delivery, we administer pharmacologic aspiration prophylaxis, and perform rapid sequence induction and intubation. After 24 hours, we assess risk factors for aspiration and individualize the decision to perform rapid sequence induction and intubation and administer aspiration prophylaxis. (See 'Preparation for anesthesia' above and "Rapid sequence induction and intubation (RSII) for anesthesia".)

Position — The patient is positioned supine. The uterus can be of sufficient size to cause aortocaval compression, so consider left uterine displacement if there is evidence of supine hypotension. (See "Anesthesia for cesarean delivery", section on 'Intraoperative positioning'.)

Slight Trendelenburg is often required during the procedure to allow bowel to fall away and optimize surgical exposure.

Postoperative analgesia — PPTL produces moderate postoperative pain that resolves over the course of several days. Similar to other surgical procedures, a multimodal opioid-sparing pain management strategy should be employed. We avoid administration of long-acting neuraxial opioids (eg, morphine or hydromorphone) because they are not usually necessary, and may delay discharge due to side effects or the need for postoperative monitoring for delayed respiratory depression. (See "Anesthesia for cesarean delivery", section on 'Spinal drugs for CD'.)

We prescribe regularly scheduled acetaminophen and nonsteroidal anti-inflammatory drugs (NSAIDs), with oral opioids only as necessary. The surgeon can provide further analgesia with local anesthetic (LA) wound infiltration [23,24].

SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: COVID-19 – Index of guideline topics" and "Society guideline links: Obstetric anesthesia".)

INFORMATION FOR PATIENTS — UpToDate offers two types of patient education materials, "The Basics" and "Beyond the Basics." The Basics patient education pieces are written in plain language, at the 5^th to 6^th grade reading level, and they answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials. Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are written at the 10^th to 12^th grade reading level and are best for patients who want in-depth information and are comfortable with some medical jargon.

Here are the patient education articles that are relevant to this topic. We encourage you to print or e-mail these topics to your patients. (You can also locate patient education articles on a variety of subjects by searching on "patient info" and the keyword(s) of interest.)

●Basics topic (see "Patient education: External cephalic version (The Basics)")

SUMMARY AND RECOMMENDATIONS

Preoperative fasting — Patients who undergo cerclage, external cephalic version (ECV), or postpartum tubal ligation (PPTL) should follow preoperative fasting guidelines, and if general anesthesia is performed, they may require pharmacologic prophylaxis for aspiration. (See 'Preparation for anesthesia' above.)

Airway concerns — Difficulty with airway management may increase over the course of pregnancy, and the incidence of failed intubation is higher in pregnant patients. Neuraxial anesthesia is preferred when possible during pregnancy, primarily to avoid the need to manage the airway. (See 'Airway concerns' above.)

Cervical cerclage

●Transvaginal cerclage can be performed with neuraxial or general anesthesia. For patients in whom either neuraxial anesthesia or general anesthesia would be appropriate for cerclage, we suggest neuraxial anesthesia (Grade 2C), and prefer single-shot spinal or combined spinal-epidural (CSE). (See 'Choice of anesthetic technique' above.)

●For neuraxial anesthesia for transvaginal cerclage, sensory blockade to T8 to T10 is necessary. (See 'Single-shot spinal and combined spinal-epidural anesthesia' above.)

●Principles for management of general anesthesia for transvaginal cerclage are similar to those that are used for cesarean delivery. For patients at <18 weeks gestational age and without risk factors for aspiration, we use a supraglottic airway (SGA) for airway management. For other patients, we perform rapid sequence induction and intubation and administer pharmacologic aspiration prophylaxis. (See 'General anesthesia' above.)

●Transabdominal cerclage may be performed prior to conception, or during early pregnancy. For pregnant patients, principles of anesthetic management are similar to transvaginal cerclage. For neuraxial anesthesia, a sensory level from sacral levels to T8 is required. (See 'Transabdominal cerclage' above.)

External cephalic version

●Neuraxial anesthesia increases the likelihood of successful ECV, compared with intravenous (IV) or no analgesia. (See 'Analgesia versus no analgesia' above.)

●Patients who undergo ECV are at a small risk of requiring emergency cesarean birth. Therefore, in our practice patients follow preoperative fasting guidelines and have an intravenous catheter placed before ECV, but practice varies and not all experts do this in their practice. (See 'Preparation and setting for ECV' above.)

●When neuraxial analgesia/anesthesia is used, we suggest the use of CSE for ECV rather than single-shot spinal, primarily to allow extension of the anesthetic for emergency cesarean birth if necessary (Grade 2C) (see 'Choice of neuraxial technique' above). We base neuraxial drug doses for ECV on the plan for obstetric management, patient factors, and the likelihood of successful ECV. In general, we increase the dose of intrathecal local anesthetic (LA) for patients at higher risk of cesarean birth, and/or higher risks associated with general anesthesia if it is required, and/or patients who will undergo cesarean birth following unsuccessful ECV. (See 'Neuraxial analgesia/anesthesia drug doses' above.)

Postpartum tubal ligation

●The physiologic changes of pregnancy and labor and delivery resolve to a varying degree during the immediate postpartum period, and may still be present when PPTL is performed. (See 'Timing of postpartum tubal ligation' above.)

●For patients in whom either neuraxial anesthesia or general anesthesia would be appropriate, we suggest the use of neuraxial anesthesia for PPTL (Grade 2C). PPTL requires a bilateral spinal dermatomal level of T6 to T8. (See 'Choice of anesthetic technique' above.)

●For patients with a labor epidural catheter in situ, we attempt to reactivate the epidural for PPTL if the epidural worked well for labor, does not appear to have migrated out of the epidural space, and if reactivation is attempted within 24 hours of placement of the epidural catheter. (See 'Patients with a labor epidural catheter in situ' above.)

●For patients in whom attempted reactivation of a labor epidural results in inadequate block (eg, partial, patchy, or unilateral), we remove the epidural catheter and perform a low dose single-shot spinal (ie, 1.0 to 1.2 mL of 0.75% hyperbaric bupivacaine plus fentanyl 15 to 20 mcg), sequential CSE, or general anesthesia. (See 'Patients with a labor epidural catheter in situ' above.)

●For patients without an epidural catheter in situ, we perform spinal anesthesia. If general anesthesia is necessary, we perform rapid sequence induction and intubation for patients within 24 hours of delivery, or with risk factors for aspiration. (See 'Patients without an epidural catheter in place' above.)