Caring for the Obstetrical Patient with Opioid Use Disorder

Anesthesiologists care for many patients as their peri-delivery physicians by providing labor analgesia and anesthesia during caesarean sections. Obstetric anesthesiologists provide peripartum care to healthy parturients as well as those with multiple co-existing conditions. Women with a dependence on opioids or opioid use disorder (OUD) who present for delivery can present unique challenges to the safe delivery of obstetrical care.

Provisional data from the Centers for Disease Control and Prevention’s National Center for Health Statistics indicate that there were an estimated 100,306 drug overdose deaths in the United States during 12-month period ending in April 2021. This was an increase of 28.5% from the 78,056 deaths during the same period the year before.¹ Over 70% of these deaths involved an opioid. In Texas, cases of drug related deaths are increasing as well with a reported 14.1/100,00 death rate related to drug overdose in 2020.²

Harris County is the most populated county in Texas. Recent data shows that, in Harris County alone, illicit fentanyl use kills an average of greater than one person every day. Fatal drug overdoses increased 52% from 2019 to 2021 according to Harris County Institute of Forensic Sciences data. Deaths involving fentanyl skyrocketed by a whopping 341% in the same period, from 104 to 459.³ Illicitly manufactured fentanyl is being laced with other recreational drugs such as benzodiazepines and other legal prescription opioids, unbeknownst to many users. This opioid pandemic has also impacted the obstetric population. Data shows that 9.4/1000 births were affected by substance use disorder in Texas in 2016.⁴ Anesthesiologists need to be prepared to care for even more parturients with chemical addiction, especially in relation to opioids, as the number of affected patients continues to grow. We will discuss important aspects of this care as it relates to our obstetrical population.

Pregnancy related complications

Pregnant women with an opioid use disorder (OUD) frequently have limited or absent prenatal care and may suffer from a variety of coexisting conditions such as fetal growth restriction, increased risk of placental abruption, intra-uterine fetal demise, or preterm labor. Patients who are acutely intoxicated with opioids and stimulant drugs such as cocaine or amphetamines during the peripartum period have a higher risk of acute hypertensive emergency or maternal hemorrhage (e.g., placental abruption). Ideally, pregnant women with OUD should be referred to a specialized center for addiction treatment, however, their lack of prenatal care often makes this challenging.⁵ In addition, patients may present to the labor suite with symptoms of withdrawal from opioids or other substances.

Infectious diseases

Intravenous drug abuse predisposes these patients to infective endocarditis and valvular abnormalities along with difficult intravenous access. In addition, these patients are at higher risk for other infectious diseases such as sexually transmitted infections, hepatitis or human immunodeficiency virus related illnesses and should be carefully screened. Achieving intravenous access above the diaphragm in pregnant intravenous drug abusing parturient is challenging and requires the anesthesiologist to be facile with the use of ultrasound.

Psychiatric conditions

Many patients with addiction to opioids have coexisting psychiatric illnesses such as depression, anxiety or post-traumatic stress disorders (PTSD). Coordination with an addiction psychiatrist and a psychologist is ideal, if available, during the prenatal period. Anesthesiologists should be familiar with drug interactions with common anti-depressants and anti-psychotic drugs. Although supervised detoxification is not recommended during pregnancy, one may encounter patients in acute withdrawal from opioids. Many patients are co-using other substances and a urinary drug screen should be performed to identify these substances.

Trauma informed care

An important aspect to consider while caring for patients with OUD is past trauma. Past physical or sexual abuse may contribute to distrust of others, including healthcare personnel and the entire medical system. The care team should attempt to develop a rapport with a patient to establish trust in order to improve patient engagement in care throughout the pregnancy. Having transparency and establishing realistic goals is essential for safe care of both mother and baby. Information about past experiences with pain management is important for development of a personalized plan for comfortable delivery. A shared decision-making model between the anesthesiology team and the patient is vital. In some circumstances, engagement of family members in care-planning can be helpful.

Treatment of addiction in the peripartum period

Patients in treatment for opioid addiction are initiated on Medication Assisted Treatment (MAT) with an opioid agonist. For pregnant women with an OUD, opioid agonist pharmacotherapy is the recommended therapy and is preferable to medically supervised withdrawal because withdrawal is associated with high relapse rates, ranging from 59% to more than 90%, and poorer neonatal outcomes.5 Relapse poses grave risks, including communicable disease transmission, accidental overdose because of loss of tolerance, obstetric complications, and lack of prenatal care.^5,6 Opioid agonist treatment is known to prevent opioid withdrawal symptoms, reduce relapse risk, improve adherence to prenatal care and substance use disorder (SUD) treatment programs and reduces the risk of obstetric complications.⁵ Methadone or buprenorphine/naloxone (Suboxone®) are the most common drugs that are used to treat OUD during pregnancy. It is recommended to continue the MAT in the peri-partum period. It is important to avoid use of opioid agonist-antagonist such as nalbuphine and butorphanol in patients on MAT as this will precipitate acute withdrawal. During the third trimester, metabolic changes and rapid drug metabolism may necessitate dose adjustment with a split dosing for methadone and buprenorphine. This ensures adequate bioavailability of MAT drugs and prevents withdrawal symptoms. It is important to recall that methadone has significant pharmacokinetic interactions with many other medications, such as anti-retroviral agents, and can prolong the QTc interval in a dose-related fashion.⁵

Peripartum analgesia

Pregnant women with an OUD should not be denied appropriate pain relief. Labor analgesia can be successfully provided with a lumbar epidural with a dilute local anesthetic and small dose of opioid in the epidural solution (e.g., 0.1 ropivacaine with 2 mcg/mL fentanyl). Neuraxial anesthesia with local anesthetic and preservative free morphine for acute post-cesarean pain is the preferred anesthetic for cesarean delivery. Scheduled non-opioid adjuncts such as acetaminophen and non-steroidal anti-inflammatory drugs should be utilized as first line agents for breakthrough pain. Epidural analgesia with a patient controlled epidural anesthesia infusion and regional blocks such as a transversus abdominis plane or quadratus lumborum blocks should be considered in patients with difficult to manage post-cesarean pain. For post-operative pain, short-acting full opioid agonists can be used if needed. Physicians should anticipate that higher than usual doses may be required to achieve adequate pain control due to tolerance. Effective management of acute post-operative pain is known to decrease the incidence of post-traumatic stress disorder, development of chronic pain, or relapse into addiction. Unnecessary opioids at discharge should be avoided.

Social and environmental factors

Many social and environmental factors may present barriers to caring for pregnant mothers with OUD. Many of these women may be dealing with the legal system and may have open Child Protection Services cases for their other children. There is always a fear that the active use of illicit substances during pregnancy may result in separation of the newborn and the mother soon after birth of the child. Hence, many women may be highly motivated during pregnancy to start and stay in treatment programs for their SUD. The psycho-social component is best managed by group therapy, possibly at a residential in-patient treatment center specifically dedicated to pregnant and post-partum women.

Neonatal care

Neonates born to mothers with OUD may have low birth weight and lower Apgar scores at birth.⁵ The neonates need to be monitored for development of an abstinence syndrome called Neonatal Opioid Withdrawal Syndrome (NOWS) by neonatology team. NOWS is a constellation of symptoms that vary in severity and can include seizures, irritability, diarrhea, vomiting, sleep issues, fever, and in rare cases, death. Neonates diagnosed with NOWS have significantly longer hospital stays (~3.5 times as long as non-NAS newborns) leading to increased medical costs and long-term neurodevelopmental morbidity. Approximately 50-90% of neonates born to OUD mothers develop the abstinence syndrome. Non-pharmacological treatment options such as ‘Eat, Sleep, Console’ are utilized initially and adjuvant opioids are used as needed.⁷ Interestingly, the use of naloxone to treat neonates who have respiratory depression at birth due to the maternal opioid use has fallen out of favor and is no longer recommended due to the complexities related to indications, dosing, and the limited duration of action naloxone.⁷ For women on MAT, breast feeding is still encouraged if there are no other contraindications.

Management of pregnant women with OUD requires the anesthesiologist to closely collaborate with multi-faceted team of maternal fetal medicine, neonatology, addiction psychiatry, social work, recovery coaches and inpatient/outpatient treatment centers. There is significant stigma associated with opioid abuse among various healthcare teams. Education to address this stigma and an understanding that safe and effective analgesia can be provided for patients with OUD is vital. Anesthesiologists can lead a patient-centered and value-based care approach during this national public health crisis for this challenging subset of patients.

References:

1. Hedegaard H, Miniño AM, Warner M. Drug overdose deaths in the United States, 1999–2019. NCHS Data Brief, no 394. Hyattsville, MD: US Department of Health and Human Services, CDC, National Center for Health Statistics; 2020

2. CDC.gov

3. https://www.houstonchronicle.com/news/houston-texas/houston/article/Deaths-tied-to-fentanyl-jump-in-Harris-County-17001856.php

4. Van Horne B, Mandell D, Vinez, M, Nong Y, Correa N, Keefe R; Supporting mothers and infants impacted by perinatal opioid use: a cross-sector assessment Houston and San Antonio, Texas; Perinatal Opioid Report March 2019. Accessed at https://www.texaschildrens.org/sites/default/files/uploads/documents/Perinatal%20Opioid%20Report%20Final_%20march%202019.pdf

5. Committee Opinion No. 711: Opioid Use and Opioid Use Disorder in Pregnancy. Obstet Gynecol. 2017 Aug;130(2):e81-e94. doi: 10.1097/AOG.0000000000002235. PMID: 28742676.

6. Strang J, McCambridge J, Best D, Beswick T, Bearn J, Rees S et al. Loss of tolerance and overdose mortality after inpatient opiate detoxification: follow up study BMJ 2003; 326 :959 doi:10.1136/bmj.326.7396.959

7. Anbalagan S, Mendez MD. Neonatal Abstinence Syndrome. [Updated 2021 Jul 22]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK551498/