E. Which neuraxial anesthetic is best for postpartum tubal sterilization?
KEYPOINTS | |
1.Although postpartum tubal ligation is considered an “urgent” procedure1 because of the consequences of failure to sterilize, the procedure should not be attempted when it could compromise other aspects of patient care.2 2.Timing of the procedure should be based on anesthetic and obstetric risk factors as well as patient preferences. 3.If postpartum tubal sterilization is anticipated within 8 hours of delivery, neuraxial anesthesia should be encouraged during labor and delivery. 4.There should be no oral intake of solid foods within 6 to 8 hours of surgery. 5.Aspiration prophylaxis should be considered. 6.Neuraxial techniques are preferred. 7.Epidural catheters placed for labor may be more likely to fail with longer postdelivery time intervals. | |
POSTPARTUM TUBAL LIGATION (PPTL) also known as postpartum tubal sterilization, is a common and effective form of birth control used in the United States. It ranks after the oral contraceptive pill as the second most common form of birth control method used by women today.3 Although estimates suggest that it is performed in approximately 10% of hospital deliveries,3 only 50% of the women who request postpartum sterilization at the time of contraception counseling receive the procedure. Postpartum sterilization is technically easier for obstetricians and avoids the inconvenience and cost of a second hospital visit. Although the procedure should not compromise other aspects of patient care,2 there is a significant cost to the patient and health care system when the request for sterilization is unfulfilled.4 PPTL is considered an “urgent” procedure by the American College of Obstetricians and Gynecologists (ACOG)1 because of the consequences of failure to sterilize. However, both obstetric and anesthetic considerations can influence the timing of tubal sterilization. This chapter reviews timing as well as surgical and anesthetic considerations of PPTL.
I.American Society of Anesthesiologists Practice Guidelines for Obstetric Anesthesia: recommendations for postpartum sterilization
The American Society of Anesthesiologists (ASA) Task Force on Obstetric Anesthesia has published Practice Guidelines for Obstetric Anesthesia, which include recommendations for postpartum sterilization (see Table 21.1).2
II.Postpartum anatomic and physiologic changes
A. Cardiovascular changes. Cardiovascular changes occur immediately after delivery.
1. For several days following delivery, there is a period of relative hypervolemia, increased venous return, and a shift of fluid from the interstitium into the circulation. The hypervolemia and increased venous return result from release of vena caval compression and reduced lower extremity venous pressure. Removal of the placenta results in (i.e., volume returned to the circulation exceeding blood loss).
2. In the immediate postpartum period, cardiac output and stroke volume increase as much as 75% above predelivery levels. Within 1 hour, both stroke volume and heart rate decrease, reducing cardiac output to approximately 30% of prelabor values. Cardiac output decreases to prelabor values within 48 hours of delivery. Heart rate decreases rapidly immediately after delivery and reaches a prepregnant rate 2 weeks following delivery. Stroke volume is elevated above prelabor levels for 48 hours and gradually declines over the next 24 weeks.
3. Doppler and M-mode echocardiographic evaluations of postpartum patients have determined that left ventricular wall thickness and mass remain elevated up to 24 weeks’ postpartum. However, multiparous patients (more than four pregnancies) who were studied approximately 13 years after their last pregnancy demonstrated complete reversibility of all changes (e.g., left ventricular mass, cardiac chamber size, diastolic and systolic function) when compared with age-matched nulliparous controls.5
B.Gastrointestinal changes. Gastrointestinal changes during pregnancy predispose parturients to reflux of gastric contents. Reflux is a well-known risk factor for acid aspiration. Do these changes persist in the postpartum period and increase risk for aspiration?
1. Anesthesiologists have been concerned about the risk of maternal aspiration associated with PPTL in the postpartum period. However, a review of anesthetic-related maternal mortality determined that there were no maternal deaths associated with maternal aspiration during PPTL.6
2. Several factors contribute to lower esophageal sphincter tone and reflux during pregnancy. However, many of these changes resolve soon after delivery.
a. During pregnancy, plasma progesterone concentrations increase resulting in relaxation of the lower esophageal sphincter and reflux. Because progesterone is produced primarily by the placenta, progesterone concentrations decline rapidly in the first 2 hours after delivery and approach levels seen during the luteal phase of the menstrual cycle by 24 hours postpartum.7
b. During pregnancy, the gravid uterus alters the position of the stomach, displacing the esophagus into the thorax. This mechanical change reduces lower esophageal sphincter tone resulting in reflux before delivery.
3. Several studies have assessed gastric emptying during labor and postpartum.8 Parturients who are >18 hours postpartum demonstrate gastric emptying, volume, and pH similar to nonpregnant women. However, data is limited on the first 8 hours postpartum.
a. All parturients demonstrate delayed gastric emptying of solids during labor.
b. Parenteral, intrathecal, and bolus-dose epidural opioids can delay gastric emptying during labor. These effects likely continue into the early postpartum period.
c. Gastric emptying of clear liquids, including isotonic sports drinks, does not appear to be delayed unless opioids have been administered.
4. The preponderance of evidence suggests that if only pregnancy-induced changes in gastrointestinal function are considered, postpartum patients are not at increased risk of aspiration.
CLINICAL PEARLMajor anatomic and physiologic changes occur during pregnancy and labor and delivery. Some changes extend into the postpartum period and can affect timing and choice of anesthetic for tubal sterilization.
III.Timing of postpartum tubal sterilization
A. Interval versus postpartum tubal sterilization. The timing of PPTL can be affected by medical and nonmedical issues (see Table 21.2). Women who request PPTL and do not receive it are more likely to become pregnant within 1 year of delivery (47%) compared to women who did not request the procedure (22%).9 An immediate tubal sterilization performed within 8 hours of delivery may decrease length and cost of hospital stay but there may be reasons to delay the PPTL beyond the 8-hour time period.
1. Consent. Tubal sterilization is considered a permanent form of contraception. A patient’s desire for permanent sterilization is often discussed with her obstetrician before labor and delivery, but some patients request tubal sterilization during labor and delivery or the early postpartum period. Medicaid Title XIX requirements, state laws, and insurance regulations may require a specific time interval between the tubal sterilization and when the obstetrician obtains consent. Such requirements may limit access to tubal sterilization in low-income and underserved groups, but recently, these regulations have been questioned10 and the ACOG Committee on Health Care for Underserved Women has recommended revising the Medicaid Title XIX requirements to establish fair and equitable access to sterilization procedures.1 Currently, specific Medicaid Title XIX requirements include11:
a. The patient must be 21 years of age and mentally competent when the consent is signed.
b. Consent must be obtained 30 days prior to sterilization. A signed copy of the consent form must be available or verified at the time of the procedure.
c. In cases of preterm delivery or emergency abdominal surgery, the 30-day waiting period may be waived. However, 72 hours must lapse between the time of the consent and procedure.
d. The consent is valid for 180 days after the consent is obtained.
e. Consent is invalid if it is obtained during childbirth or while the patient is in labor.
f. Consent must not be obtained while the patient is undergoing abortion or is under the influence.
2. Patient uncertainty. Patients may be unsure about postpartum sterilization. These patients should be aware that many factors affect the incidence of successful pregnancy following tubal sterilization. In such cases, reanastomosis and/or extracorporeal fertilization may be required unless there are medical, financial, or religious considerations.
3. Patient regret. In addition to these considerations, there are other concerns that may affect a woman’s decision to proceed with postpartum tubal sterilization. Patients with postpartum sterilization have reported increased rates of menstrual dysfunction and subsequent hysterectomy compared with nonsterilized women. In these cases, sterilized women may choose hysterectomy as a therapeutic alternative more frequently than nonsterilized women. Patient regret (i.e., dissatisfaction with permanent sterilization) is also a recognized long-term concern. Although the risk of regret is increased when patients are younger (aged 20 to 24 years), the odds of regret are similar in women who have undergone postpartum sterilization (1 year after sterilization) compared to women who undergo interval sterilization.12 In all cases, the patient needs to be appropriately counseled and committed to her decision. This requires prenatal dialogue between the patient and her physician.
4. Sterilization failure. Despite these concerns, patients should also be aware that tubal sterilization failures do occur at a rate of 7.5 pregnancies per 1,000 sterilizations. Postpartum sterilizations have the lowest failure rate of any other method of tubal sterilization, especially if fallopian tube resection occurs.13
5. The anesthesiologist should consider the following factors when immediate tubal ligation is planned within 8 hours of delivery:
a. The decision to administer general anesthesia within 8 hours of delivery should be considered carefully.
b. What is the duration of the fast for solids?
c. Did the patient receive opioids during labor?
d. Is a functional epidural catheter in place?
B. Timing from the obstetrician’s perspective
1. Obstetricians often prefer postpartum sterilization because interval procedures require laparoscopic visualization of the fallopian tubes. However, hysteroscopic Essure™ tubal sterilization is now very popular and avoids the laparoscopic approach for tubal sterilization remote from delivery. This approach also avoids abdominal incisions and the procedure can be performed in an office-based setting with paracervical block and sedation. However, a recent review of all randomized controlled trials determined that for hysteroscopic Essure™ tubal sterilization overall pain scores were not significantly reduced by either paracervical block with lidocaine or conscious sedation.14
a. Laparoscopic interval complications. Postpartum procedures are technically easier, require less equipment, and are associated with fewer serious complications (e.g., subcutaneous emphysema, pneumothorax, pneumomediastinum, venous gas emboli) compared with laparoscopic interval sterilization.
b. Postpartum tubal complications are rare and include:
(1) Difficult identification and mobilization of the tube, skin infections, intraoperative bleeding, or delayed hemorrhage.
(2) Delayed hemorrhage can result in retroperitoneal hematoma, but this is an infrequent complication.
(3) Other rare but serious complications include bowel laceration and vascular injury.
2. Two important considerations may affect the decision to proceed with postpartum sterilization.
a. Uterine atony and hemorrhage. Although multiparous patients are more likely to request these procedures, they are at increased risk for uterine atony and associated postpartum hemorrhage. Fortunately, atony usually subsides within 12 hours of delivery, making postpartum sterilization possible if the hematocrit is stable and within normal limits.
b. Newborn assessment. A major obstetric disadvantage of an early postpartum procedure is inadequate time to assess the newborn. If newborn resuscitation is necessary or the newborn is transferred to the intensive care unit, postpartum sterilization may be delayed.
3. High-risk patients. If patients have serious medical comorbidities (e.g., cardiovascular disease) or complicated obstetric histories, an obstetric concern is the risk of subsequent pregnancy. If the obstetrician fears that a patient may not return for interval sterilization 6 weeks’ postpartum, the decision to proceed with tubal sterilization in such a high-risk patient must be weighed against the risk of a subsequent pregnancy. Because of continuing resolution of the physiologic changes of pregnancy in the early postpartum period, some women with serious medical comorbidities may benefit from interval sterilization. However, general anesthesia, obesity, diabetes mellitus, and a previous history of abdominal or pelvic surgery have been identified as independent predictors for complications in women undergoing interval sterilization.15
4. The ASA Practice Guidelines for Obstetrical Anesthesia state that a PPTL should not be attempted when it might compromise other aspects of care.2 However, PPTL is considered an “urgent” procedure1 because of the consequences of failure to sterilize.
a. Timing of the tubal sterilization will depend on the adequacy of labor and delivery staffing.
b. Patients should be aware that tubal sterilization cannot be guaranteed despite the best attempts of the hospital team.
c. To avoid rescheduling and interval sterilization, hospitals may employ temporary mechanisms to increase staffing when labor and delivery is busy and a tubal sterilization is requested.
CLINICAL PEARLThe timing of the procedure should be individualized and based on anesthetic risk factors (e.g., delayed gastric emptying in patients who have received opioids during labor), obstetric risk factors (e.g., maternal fever, chorioamnionitis, sepsis, blood loss, hemodynamic instability), and patient preferences.2
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