Obstetric anesthesia for patients with opioid use disorder or opioid tolerance

INTRODUCTION — Opioid use during pregnancy has increased in parallel with the opioid epidemic. Providing peripartum analgesia and anesthesia may be uniquely challenging in patients who use opioids or who have opioid use disorder (OUD) due to opioid tolerance, opioid induced hyperalgesia, and the potential for withdrawal. This topic will discuss anesthesia and analgesia for labor and delivery in patients with OUD or opioid tolerance.

The management of OUD during pregnancy is discussed separately.

●(See "Substance use during pregnancy: Screening and prenatal care".)

●(See "Opioid use disorder: Overview of treatment during pregnancy".)

●(See "Opioid use disorder: Pharmacotherapy with methadone and buprenorphine during pregnancy".)

ANTENATAL ANESTHESIA CONSULTATION — Screening for substance use and misuse is part of routine obstetric care (see "Substance use during pregnancy: Screening and prenatal care", section on 'Screening for substance use'). Once identified, parturients who chronically use opioids may benefit from antenatal high-risk anesthetic consultation in order to address patient concerns and to create a plan for peripartum analgesia or anesthesia, often in coordination with the clinicians who prescribe opioids or manage OUD [1,2].

Evaluation of pregnant patients with OUD for concomitant medical and psychosocial disorders is discussed separately. (See "Opioid use disorder: Overview of treatment during pregnancy", section on 'Pretreatment maternal evaluation'.)

In addition to routine obstetric preanesthesia evaluation, the following areas are of particular focus during the anesthesia consultation for patients with OUD or who are currently prescribed opioids.

Current opioid therapy — Patients with chronic pain or OUD may be taking prescription opioids, including buprenorphine or methadone for OUD. The quantity of opioids used daily should be ascertained as accurately as possible, including individual doses, intervals, and total daily dose, and should be reconfirmed at the time of delivery. In general, the patient's baseline medication regimen for OUD, including buprenorphine or methadone, should be continued in the peripartum period in order to prevent maternal or neonatal withdrawal and if applicable, to maintain the existing level of chronic pain control. However, the baseline medication for OUD (MOUD) regimen is not sufficient to treat peripartum pain. (See "Opioid use disorder: Pharmacotherapy with methadone and buprenorphine during pregnancy", section on 'Intrapartum and postpartum buprenorphine dosing' and "Opioid use disorder: Pharmacotherapy with methadone and buprenorphine during pregnancy", section on 'Intrapartum and postpartum methadone dosing'.)

For patients with OUD that is untreated, baseline opioid dose may be impossible to determine, particularly in the setting of illicit opioid use. Management to prevent withdrawal for patients with untreated OUD is discussed below. (See 'Continue baseline opioid' below.)

Concomitant medications — Up to 35 percent of opioid-dependent pregnant patients report use of additional pain or psychotropic medications [3]. The use of any illicit, psychotropic, or additional pain medication should be determined to anticipate both increased risk of withdrawal during the hospitalization, and a compounded risk of respiratory depression.

Patients should be asked about nicotine use, which is more common in patients with OUD and may be an independent risk factor for increased postpartum pain after delivery in patients with OUD [4].

Concurrent psychiatric conditions or social stressors — Coexisting depression and anxiety are common in patients with OUD, and these conditions and potential psychosocial stressors should be identified during the preanesthetic consultation [4,5]. (See "Opioid use disorder: Psychosocial management" and "Substance use disorders: Psychosocial management" and "Treatment of co-occurring anxiety-related disorders and substance use disorders in adults".)

Both pre-delivery anxiety and depression and severe acute postdelivery pain are associated with increased risk for chronic pain 3, 6, and 12 months after cesarean delivery [6]. Furthermore, higher intensity of immediate postpartum pain after vaginal or cesarean delivery is predictive of postpartum depression. [7]. Taken together, optimizing pre-delivery anxiety and depression and acute postdelivery pain are important priorities for patients with OUD. Resources including psychology or psychiatry consultation and social support networks may be beneficial and should be explored.

Patient concerns — During the pre-anesthesia visit, the anesthesia clinician should elicit and address patient concerns, which may include anxiety over and fear of pain, possibility of withdrawal, and the possibility of negative interactions with medical staff. The visit should be empathetic and nonjudgmental, with a focus on building a strong patient-provider relationship, lifting any stigma associated with opioid use, and establishing appropriate expectations for care. The discussion should include the patient's pain tolerance and her expectations for labor analgesia or cesarean delivery.

It may be helpful to discuss any prior history of withdrawal, and to reassure the patient that preventing withdrawal is a key focus throughout the peripartum period.

CREATING A MANAGEMENT PLAN — Effective management of patients who chronically use opioids or with OUD requires an integrated approach that includes the patient, obstetrician, and anesthesiologist, and may include the pain management clinician and psychiatrist or addiction medicine specialist. The goal is to develop a patient-centered individualized plan that is realistic, safe, and attainable, recognizing the variability of analgesic requirements and unpredictability of labor and delivery [8,9].

The limited available literature on management of analgesia and anesthesia for labor and delivery for patients with OUD consists of small case series and retrospective reviews which reflect heterogenous management strategies [4,10-16]. Some studies have reported increased need for postpartum analgesia in patients who chronically use opioids, while others have not. Examples include the following:

●In a single institution retrospective case control study of 68 pregnant patients maintained on methadone for OUD (35 after vaginal delivery, 33 after cesarean delivery), peripartum analgesia was compared with controls [13]. Patients on methadone for OUD had similar pain and analgesia during pregnancy, and similar opioid use after vaginal delivery despite reporting increased pain after delivery. After cesarean delivery, patients on methadone had increased postoperative pain (5 versus 3 on a scale of 0 to 10) despite increased opioid use that was in addition to their maintenance methadone dose (92 versus 54 oxycodone milligram equivalents/24 hours). Eighty percent of patients in both study groups received neuraxial analgesia. Of note, all cesarean delivery patients received spinal anesthesia, but only 27 and 21 percent received long-acting intrathecal opioid in the OUD and control groups, respectively. Furthermore, no alternate truncal blocks such as a transversus abdominis plane (TAP) were performed in the OUD or control groups. The external validity of these findings may be limited, however, as intrathecal opioids are now rarely withheld and truncal blocks have increased in use.

●A separate retrospective case control study from the same institution showed similar results for pregnant patients with OUD on buprenorphine; 63 patients who delivered while on buprenorphine for OUD (44 vaginal, 19 cesarean) had similar intrapartum pain scores compared with controls [14]. Again, patients maintained on buprenorphine reported more pain following vaginal delivery, without an increase in opioid use; after cesarean delivery, buprenorphine as medication for opioid use disorder (MOUD) was associated with increased pain and a 47 percent increase in opioid use (89 versus 81 oxycodone milligram equivalents). Similar to the study above, over 80 percent of all patients received neuraxial labor analgesia, but very few patients received long-acting intrathecal opioids for cesarean delivery.

●A retrospective analysis of data collected as part of the Maternal Opioid Treatment: Human Experimental Research trial analyzed data for 37 patients receiving treatment for OUD with buprenorphine versus methadone, compared with patients who were not opioid dependent [4]. Pain and analgesic use after vaginal delivery were similar between groups; patients on MOUD received more nonsteroidal antiinflammatory drugs (NSAIDs) but fewer opioids after cesarean delivery than patients who were not opioid dependent. Patients on MOUD requested epidural labor analgesia more often (38.1 versus 14.3 percent), though generalizability is uncertain due to the low epidural utilization rate in both groups.

●In a single institution retrospective review of 2979 patients who underwent cesarean delivery, 123 of whom were taking buprenorphine or methadone for treatment of OUD, patients who were taking MOUD consumed more additional opioids (median total 99 versus 30 milligram morphine equivalents) and had higher peak pain scores (8.2 versus 5.5/10) in the first 24 hours after surgery [17]. Outcomes were similar in patients who were taking buprenorphine versus methadone.

GENERAL PRINCIPLES — General principles of management for obstetric patients who chronically use opioids are similar to those that apply to nonpregnant patients who chronically use opioids. For most patients, baseline opioid should be continued. Neuraxial anesthesia techniques are preferred for both labor analgesia and operative delivery, supplemented with multimodal nonopioid analgesics, and additional opioids added as necessary. Overarching goals are to provide adequate analgesia, and to avoid withdrawal, oversedation, and respiratory depression (table 1). (See "Management of acute pain in the patient chronically using opioids for non-cancer pain", section on 'Treatment goals'.)

Continue baseline opioid — For all patients who chronically use opioids or who have OUD, baseline opioid therapy should be continued throughout the peripartum period to prevent withdrawal and to maintain the antepartum level of analgesia, if applicable. For patients who are unable to swallow or absorb oral medications, an oral dose can be converted to a parenteral equivalent (table 2). Important safeguards and details regarding opioid conversion are discussed separately. (See "Cancer pain management with opioids: Optimizing analgesia", section on 'Equianalgesic opioid dose conversion'.)

While it was previously recommended that medication for opioid use disorder (MOUD) be stopped prior to surgery or other episodes associated with acute pain, this is no longer recommended. Discontinuation may precipitate a relapse in the peripartum period, and can expose the patient and the newborn to potential risks of withdrawal. (See "Opioid use disorder: Pharmacotherapy with methadone and buprenorphine during pregnancy".)

For patients on MOUD admitted for labor and delivery, we typically continue the patient’s prescribed MOUD dose; while methadone dosing is typically once daily, a more frequent dosing regimen for buprenorphine (three to four times daily) has been recommended during pregnancy to prevent withdrawal and sustain adherence, due to its altered pharmacokinetics during gestation [18,19]. In addition to baseline MOUD, we use the typical analgesic regimens used for patients without opioid tolerance (ie, neuraxial labor analgesia, multimodal post-cesarean delivery analgesia including neuraxial opioids). Options for managing breakthrough pain include supplemental doses of MOUD if the baseline dose was not maximized, use of other opioids, or for cesarean delivery, peripheral nerve blocks. (See 'Post-cesarean delivery analgesia' below.)

The decision to continue or modify the dose of buprenorphine before surgery or an acute pain episode is discussed in detail separately. (See "Management of acute pain in adults with opioid use disorder", section on 'Whether to continue buprenorphine during pain management'.)

Patients with untreated OUD are at high risk for withdrawal when hospitalized without access to opioids they regularly consume outside of the hospital. For patients who use illicit opioids, baseline opioid dose may be impossible to determine. In this setting, patients admitted for delivery with untreated OUD who are willing to start MOUD can be initiated on methadone or buprenorphine to minimize withdrawal, with additional rescue opioid treatment for analgesia as needed. Patients who are unwilling to start MOUD and who receive standard anesthesia and analgesia for labor and delivery should be closely monitored for withdrawal.  

Use multimodal analgesia — Multimodal analgesia should be used for all patients, including neuraxial analgesia, nonpharmacologic strategies, regional anesthesia techniques as applicable, nonopioid analgesics, and opioids when necessary. (See 'Labor analgesia' below and 'Postpartum analgesia' below.)

Avoid using opioid antagonists — Opioid antagonists or agonist-antagonists can precipitate acute withdrawal and should be avoided [13,20]. Examples of these drugs are nalbuphine hydrochloride, pentazocine, butorphanol tartrate, and naloxone. If any of these drugs are given inadvertently, withdrawal can be reversed with any full opioid agonist. Obstetric and nursing teams who may be accustomed to administering nalbuphine or butorphanol to obstetric patients to treat labor pain or itching should be cautioned against its use in this population, given the risk of acute withdrawal [13].

Monitor for sedation, respiratory depression, and withdrawal — Patients who chronically use opioids may be at increased risk of respiratory depression when additional opioids or sedatives are administered. These patients should be monitored similarly to high-risk patients receiving neuraxial morphine or hydromorphone (algorithm 1).

Increased risk of adverse peripartum outcomes in patients with opioid dependence or abuse were reported in a large database study that used the US Nationwide Inpatient Sample [21]. Opioid dependence was associated with increased odds of maternal death (0.03 versus 0.006 percent) and cardiac arrest (0.04 versus 0.01 percent) during hospitalization for delivery compared with patients without opioid abuse or dependence, though the absolute risks of these events were very low. Whether these outcomes were the result of respiratory depression, withdrawal, or other confounding events or patient characteristics could not be determined.

All providers must recognize symptoms of opioid withdrawal, which may occur during admission for labor and delivery if patients do not reveal a history of OUD, if they are under treated during hospitalization, or if they inadvertently receive mixed agonist-antagonist or antagonist therapy that precipitates withdrawal (table 3). Some institutions use a tool for standardized monitoring for withdrawal (eg, the Clinical Opioid Withdrawal Scale (table 4)).

LABOR ANALGESIA — We suggest the use of neuraxial analgesia for parturients with OUD or chronic opioid use to provide optimal analgesia and minimal side effects for the parturient and fetus. For patients with contraindications to neuraxial analgesia or for those who refuse it, patient-controlled analgesia (PCA) may be offered (table 1). (See "Neuraxial analgesia for labor and delivery (including instrumental delivery)" and "Pharmacologic management of pain during labor and delivery", section on 'Patient controlled analgesia (PCA)'.)

A priority for managing patients with OUD or on chronic opioid therapy is to minimize the need for systemic opioids over and above their baseline. Thus, we counsel patients on the benefits of neuraxial analgesia, both to optimize pain relief and to avoid systemic opioids.

Neuraxial analgesia — We initiate labor epidurals for patients with chronic opioid use or OUD at the time of patient request, dosed according to standard institutional protocol, with administration of additional boluses or increased infusion rate as needed. (See "Neuraxial analgesia for labor and delivery (including instrumental delivery)".)

For patients taking methadone or buprenorphine for OUD, existing data do not suggest the need to alter doses of epidural or spinal opioids for vaginal or cesarean delivery. Patients on MOUD have pain and analgesic requirements during labor similar to patients who were not on MOUD [13,14].

Systemic analgesics — For patients with contraindications to neuraxial analgesia or who refuse it, baseline opioid dose can be increased, or other systemic opioids or nitrous oxide can be administered. For patients who receive systemic opioids, opioids with high potency or a high mu-opioid receptor affinity such as fentanyl, hydromorphone, or morphine may be preferable, particularly for patients on buprenorphine. The risks of return to substance abuse should be considered in determining whether to administer systemic opioids, given that such relapse can be associated both with exposure to systemic opioids or with poor pain control that ensues from avoidance of opioids [22]. (See "Pharmacologic management of pain during labor and delivery", section on 'Systemic analgesics'.)

●Importantly, avoid using opioid agonist/antagonist drugs for labor analgesia. (See 'Avoid using opioid antagonists' above.)

●Nitrous oxide should be used with caution in patients who take opioids because of added risk of respiratory depression. (See "Pharmacologic management of pain during labor and delivery", section on 'Nitrous oxide'.)

ANESTHESIA FOR CESAREAN DELIVERY — We do not typically modify our usual choice of anesthetic technique for cesarean delivery for patients with OUD or who chronically use opioids. We use neuraxial anesthesia with multimodal analgesia based on the doses of long-acting hydrophilic neuraxial opioids we use for patients who do not chronically use opioids. We choose the type of neuraxial anesthesia (ie, spinal, combined spinal-epidural, epidural) based on patient and obstetric factors. We may rarely offer epidural catheter placement specifically for postoperative analgesia for patients who have high levels of anxiety regarding pain control, who request maximal opioid avoidance, or who are taking very high doses of opioids. Doses of neuraxial opioids and options for post-cesarean analgesia are discussed below (table 1). (See 'Post-cesarean delivery analgesia' below.)

Patients with OUD or chronic opioid use may experience increased anxiety during neuraxial anesthesia for cesarean delivery compared with other patients. In our experience, these needs can usually be met with nonpharmacologic support, and increased need for anxiolytic medication has not been reported in the literature. We occasionally administer ketamine (eg, 10 to 30 mg IV with midazolam 1 to 2 mg IV pretreatment) as an adjunctive sedating medication in patients with OUD, if the patient has an adequate block but poor coping mechanisms during cesarean delivery.

POSTPARTUM ANALGESIA — The postpartum period is a critical time for patients with OUD or chronic opioid use as postpartum pain may be more difficult to control. Severe acute postpartum pain may be associated with increased risk of persistent pain and depression [7]. Maintenance doses of medication for opioid use disorder (MOUD) should be continued throughout the postpartum period.

Analgesia after vaginal delivery — Patients who are opioid tolerant may require enhanced analgesia after vaginal delivery, over and above routine care.

●Routine postpartum analgesia – We administer regularly scheduled acetaminophen and nonsteroidal antiinflammatory drugs (NSAIDs) starting after delivery in addition to standard postpartum pain control measures, and add opioids only as necessary. (See "Overview of the postpartum period: Normal physiology and routine maternal care", section on 'Vaginal birth'.)

●Patients with perineal tears – We offer long-acting neuraxial opioid (eg, morphine or hydromorphone) to patients who have third or fourth degree perineal tears with neuraxial anesthesia. We use doses similar to those that are used for post-cesarean delivery analgesia. (See 'Patients who have neuraxial anesthesia' below.)

Post-cesarean delivery analgesia — The optimal strategy for post-cesarean delivery analgesia has not been determined, and practice varies. Our approach is described here and appears in a table (table 1).

Patients who have neuraxial anesthesia — For these patients, we use a multimodal postoperative analgesic strategy similar to patients without OUD or chronic opioid use, based on hydrophilic neuraxial opioids and regularly scheduled nonopioid analgesics. (See "Post-cesarean delivery analgesia", section on 'Our approach'.)

●Neuraxial hydrophilic opioids – We administer the same doses of neuraxial opioids for patients who are opioid tolerant and for those who are opioid naïve (preservative free morphine 100 mcg intrathecal or 2 mg epidural), since not all opioid tolerant patients require increased postoperative analgesia [13-15], and higher opioid doses are associated with increased side effects, particularly respiratory depression and pruritus. (See "Post-cesarean delivery analgesia", section on 'Side effects and complications'.)  

There are no randomized trials on post-cesarean analgesia in this patient population, and the optimal dose of neuraxial opioids for opioid tolerant patients is unknown. Practice varies, and some authors suggest increasing the dose of neuraxial opioids above that which would be used for non-opioid tolerant patients [23].

Whether buprenorphine reduces the efficacy of neuraxial opioids is unknown, and no study has demonstrated this effect.

●Neuraxial adjuncts – Neuraxial clonidine may enhance analgesia after cesarean delivery, but is associated with increased intraoperative hypotension and sedation. Routine use is not warranted based on current data, though it may be appropriate in some patients who are expected to have difficulty with pain control, after consideration of possible side effects. (See "Post-cesarean delivery analgesia", section on 'Neuraxial adjuvants'.)

●Ketamine – We rarely administer ketamine as part of multimodal analgesia for cesarean delivery. We consider intraoperative ketamine (10 to 30 mg IV or an infusion at 3 to 5 mcg/kg/minute) for patients with a history of poor postoperative analgesia after prior surgery or for patients who are very motivated to maximally avoid opioids.

Patients who have general anesthesia — For these patients we administer regularly scheduled nonopioid analgesics (ie, acetaminophen and NSAIDs), offer bilateral transversus abdominis plane (TAP) or quadratus lumborum (QL) blocks (single injection or continuous), and start intravenous patient-controlled analgesia (PCA) with opioids, transitioned to oral opioids by postoperative day 1. When possible, we may place an epidural catheter postoperatively for continuous epidural analgesia, though the risks of limited postoperative mobility and subsequent thromboembolic events should be considered.

We often use long-acting liposomal bupivacaine for TAP blocks when needed for severe breakthrough pain, but the possibility that this group of patients, many of whom may suffer from opioid-induced hyperalgesia, may require further local anesthetic administration should be considered before administering liposomal bupivacaine. Additional local anesthetics should not be administered for 96 hours after liposomal bupivacaine, to avoid local anesthetic systemic toxicity. Use of liposomal bupivacaine in general and for TAP block for cesarean delivery is discussed separately. (See "Clinical use of local anesthetics in anesthesia", section on 'Liposomal bupivacaine' and "Post-cesarean delivery analgesia", section on 'Peripheral nerve blocks'.)

Local anesthetic wound infiltration is another option for post-cesarean delivery analgesia. The limited literature on wound infiltration suggests that benefits are modest, and likely nonexistent for patients who receive neuraxial opioids (see "Post-cesarean delivery analgesia", section on 'Wound infiltration'). We do not use wound infiltration or wound catheters in patients who receive neuraxial opioids or peripheral nerve blocks for postoperative analgesia.

Severe or ongoing pain — For severe or ongoing pain after the analgesic options described above, options include IV opioids (by intermittent bolus or PCA), rescue epidural analgesia, rescue bilateral TAP or QL blocks, and/or oral gabapentin for select patients, though there is scant evidence of efficacy of gabapentin. For patients who receive gabapentin, enhanced monitoring for sedation and respiration may be required for the mother and for breastfed neonates. Use of gabapentin for post-cesarean delivery analgesia is discussed separately. (See "Post-cesarean delivery analgesia", section on 'Adjuvant analgesics'.)

PATIENTS WITH PRIOR OUD NOW ABSTINENT — Medication for opioid use disorder(MOUD) is preferred for most patients, though some patients choose psychosocial treatment alone. Patients who are abstinent in recovery from OUD may be more vulnerable to relapse and have heightened anxiety about the medical setting, the pain of delivery, and pain relief that may be required in the peripartum period (table 1).

●There are no data to suggest that the risk of relapse is increased if neuraxial opioids are administered. Therefore, neuraxial opioids should be used for labor analgesia, for analgesia after repair of third- or fourth-degree laceration, and for post-cesarean delivery analgesia, to maximize pain relief and minimize the need for systemic opioids.

●Even patients who are currently abstinent may be opioid tolerant and may require higher doses of opioids. However, patients who have been abstinent for years likely have no increased opioid tolerance over opioid-naïve patients.

●Nitrous oxide can be offered as a nonopioid labor analgesic.

●For postpartum analgesia, we administer regularly scheduled acetaminophen and nonsteroidal antiinflammatory drugs (NSAIDs), in addition to routine care measures.

●For patients who desire maximal opioid avoidance after cesarean delivery, we may offer a combined spinal epidural technique and leave the epidural catheter in place to provide postoperative continuous epidural analgesia in addition to regularly scheduled nonopioid analgesics. Additional options include peripheral nerve blocks and/or local anesthetic wound infiltration and perioperative gabapentin. (See "Post-cesarean delivery analgesia".)

PATIENTS TAKING NALTREXONE — Naltrexone is a mu, kappa, and delta antagonist that may be used for treatment of OUD as for patients who choose to completely detoxify. If naltrexone is maintained until delivery, opioids are not likely to be effective for intrapartum and postpartum pain control. Naltrexone may over time increase the density of opioid receptors, such that the risk of side effects (eg, respiratory depression) may be increased if high doses of opioids are used (ie, the opioid antagonism is overcome), or if naltrexone is discontinued.

The efficacy of opioids is unpredictable, depending on the timing since the last dose of oral or intramuscular naltrexone. If naltrexone was not held for 48 to 72 hours or 30 days after an oral or intramuscular dose, respectively (or patients with a naltrexone implant in place), opioids will probably be ineffective. If naltrexone has been held for more than 48 to 72 hours after an oral dose or 30 days after an intramuscular dose, the patient may be more sensitive to opioids, and may be at risk for respiratory depression.

The literature on delivery in patients who are taking naltrexone is limited to small case series, with few details on peripartum pain management [24,25]. Starting naltrexone during gestation is typically avoided due to the need for detoxification and associated concerns. (See "Opioid use disorder: Overview of treatment during pregnancy", section on 'Other pharmacotherapy'.)

For patients who are taking naltrexone at the time of delivery, the following general approach is reasonable (table 1):

●Coordinate management closely with an addiction medicine specialist and the obstetric team.

●Avoid systemic and neuraxial opioids.

●Use regional anesthesia techniques with only local anesthetics for labor analgesia and post-cesarean delivery analgesia (eg, combined spinal-epidural, continuous epidural, transversus abdominis plane [TAP] or quadratus lumborum [QL] block, wound infiltration).

●If neuraxial analgesia is not possible for labor analgesia, offer nitrous oxide.

●For postpartum analgesia, administer regularly scheduled nonopioid analgesics in addition to routine care.

Management of acute pain in patients taking naltrexone is discussed in detail separately. (See "Management of acute pain in adults with opioid use disorder", section on 'Patients taking naltrexone'.)

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: Obstetric anesthesia" and "Society guideline links: Substance misuse in pregnancy".)

SUMMARY AND RECOMMENDATIONS

●Preanesthesia consultation – Important issues that should be discussed during antenatal consultation include the details of current opioid therapy, concomitant medications including illicit substances, nicotine use, and concurrent psychiatric issues. Patient concerns regarding pain management and peripartum opioid use should be explored. (See 'Antenatal anesthesia consultation' above.)

●General principles of peripartum management – Important principles for peripartum management include the following (see 'General principles' above):

•Continue baseline opioid to avoid withdrawal

•Use multimodal opioid-sparing analgesia for labor, delivery, and postpartum pain

•Avoid administering agonist-antagonist medications (eg, nalbuphine, pentazocine, butorphanol) to avoid precipitating withdrawal

•Monitor for sedation, respiratory depression, and withdrawal

Our strategy for peripartum management is shown in a table (table 1).

●Labor analgesia – We initiate neuraxial labor analgesia upon patient request, using the usual doses of local anesthetics and opioids. For patients with contraindications or who refuse neuraxial analgesia, patient-controlled analgesia (PCA) may be offered. Nitrous oxide should be used with caution because of added risk of respiratory depression (table 1). (See 'Labor analgesia' above.)

●Anesthesia for cesarean delivery – We do not modify the anesthetic for cesarean delivery for patients with chronic opioid use or opioid use disorder (OUD). We use neuraxial anesthesia, with multimodal analgesia based on usual doses of long-acting neuraxial opioids (table 1). (See 'Anesthesia for cesarean delivery' above.)

●Postpartum analgesia – For all patients we administer regularly scheduled acetaminophen and nonsteroidal antiinflammatory drugs (NSAIDs), along with routine postpartum care (table 1).

•After vaginal delivery – For patients who have third or fourth degree vaginal tears, we offer long-acting neuraxial opioids at the same doses we use for cesarean delivery. (See 'Analgesia after vaginal delivery' above.)

•Post cesarean delivery analgesia

-For patients who have neuraxial anesthesia, we administer hydrophilic neuraxial opioids at routine doses (ie, preservative-free morphine 100 mcg intrathecal or 2 mg epidural), since not all opioid tolerant patients require increased postoperative analgesia, and side effects are dose dependent. (See 'Patients who have neuraxial anesthesia' above.)

-For patients who have general anesthesia, we offer bilateral transversus abdominis plane blocks (TAP) or quadratus lumborum (QL) blocks and start IV PCA, transitioned to oral opioids by the first postoperative day. We may place an epidural catheter postoperatively for continuous analgesia. (See 'Patients who have general anesthesia' above.)

●Patients with prior OUD, now abstinent (table 1) (see 'Patients with prior OUD now abstinent' above)

•We administer neuraxial opioids for labor analgesia, for analgesia after repair of third- or fourth-degree laceration, and for post-cesarean delivery analgesia, to maximize pain relief and minimize the need for systemic opioids. There are no data to suggest that the risk of relapse is increased if neuraxial opioids are administered.

•Nitrous oxide is an option for labor analgesia for patients who prefer to delay or avoid labor epidural analgesia.

•For patients who desire maximal opioid avoidance after cesarean delivery, we may place a combined spinal-epidural for anesthesia and leave the epidural catheter in place for postoperative analgesia. Other options include TAP or QL blocks, local anesthetic wound infiltration or catheters, and/or oral gabapentin.

●Patients taking naltrexone – For patients taking naltrexone, we avoid systemic and neuraxial opioids and use neuraxial techniques with local anesthetics only. The efficacy of opioids is unpredictable depending on the timing of the last dose of naltrexone. If naltrexone still has a pharmacologic effect, opioids will probably be ineffective. If the last oral dose was >48 to 72 hours ago, the patient may be more sensitive to opioids and at risk for respiratory depression (table 1). (See 'Patients taking naltrexone' above.)