PBLD8: Maternal Substance Abuse during Pregnancy

Not only do drug-users/abusers have higher odds of in-hospital mortality, but also an extended length of delivery hospitalization (>7 days), transfusion, and oligohydramnios. In addition, well-established studies reveal a higher risk for cesarean delivery, preterm birth, and intrauterine growth restriction.

Opioid tolerance and hyperalgesia develop in women who are dependent on or abuse opioids, and they often experience more postpartum pain than the general obstetric population.

Each of these factors confers increased risk for substance use/abuse.

While each of these signs and symptoms is seen in patients with acute cocaine toxicity, a differential diagnosis of preeclampsia/eclampsia should also be explored. Urine drug toxicology should elucidate a clearer picture.

Choice of anesthetic technique depends on maternal and fetal indications for cesarean delivery as well as other mitigating factors. Timing and emergent nature of surgery secondary to fetal tracing usually determine whether general anesthesia versus neuraxial anesthesia is utilized. Maternal cocaine use can result in thrombocytopenia and/or placental abruption, both of which would contraindicate the use of a neuraxial technique. Anticipation of difficult airway, non-NPO status, lab values and other maternal factors may weigh the decision in favor of neuraxial if/when the fetal tracing has periods of recovery. Importantly, a combative, and acutely intoxicated patient may make neuraxial placement difficult. Phenylephrine has become the drug of choice to treat spinal mediated hypotension in cesarean delivery. If general anesthesia is selected, the hemodynamic response to laryngoscopy should be attenuated prior to/and during intubation with fast-acting antihypertensive medications.

Tobacco abuse in pregnancy has been associated with spontaneous abortion, ectopic pregnancy, IUGR, increased incidence of preterm premature rupture of membranes (PPROM), preterm labor, placenta previa, placental abruption, and sudden infant death syndrome (SIDS). Functional physiologic alterations, such as vascular constriction, decreased uteroplacental perfusion, and impaired oxygen exchange, may occur and adversely affect pregnancy outcomes. Interestingly, the risk of preeclampsia may be decreased in women who smoke during pregnancy. Smoking should not,however, be encouraged as a way to reduce preeclampsia risk.

Neuraxial anesthesia is preferred in tobacco users/abusers as the respiratory complications associated with general anesthesia in smokers, including bronchospasm and post-operative pulmonary complications, are avoided.

Many institutions are utilizing multimodal pain management regimens that include ERAS protocols for cesarean delivery. These protocols utilize such medications as acetaminophen, NSAIDs, gabapentin, and TAP blocks in a scheduled rather than PRN manner. Patients on medications such as Suboxone and Subutex should continue these medications throughout the hospital course. Pain-management specialists can be consulted for assistance in managing these medications.

Benzodiazepines and other sedatives, which are often used in opioid-dependent or opioid-abusing parturients to manage insomnia and anxiety, are synergistic in their respiratory depressant effects. Physician error in conversion of opioid equivalents and an association between sleep apnea and chronic opioid use may also contribute to poor outcomes. Consultation with pain-management anesthesia specialists is recommended along with maximizing multimodal perioperative pain management. More intensive intrapartum respiratory monitoring in these patients may help to prevent these complications.

When selecting amongst methadone, buprenorphine, and buprenorphine + naloxone, the decision to select a drug is based on several factors. If a single agent can be used and neonatal exposure to naloxone can be avoided, either methadone or buprenorphine should be selected. Both methadone and buprenorphine are widely used to treat opioid use disorder; however, compared with methadone, buprenorphine is associated with shorter treatment duration, less medication needed to treat neonatal abstinence syndrome (NAS) symptoms, and shorter hospitalizations for neonates. Local and state rules and regulations may impact whether a mother is placed on methadone or Subutex and familiarity with these rules can be helpful.

Women are more likely than men to be prescribed opioids, receive higher doses, and take opioids for longer durations. Emergency department visits for opioid misuse and abuse are more likely in women of childbearing age than in any other age group.

References:

1. Birnbach DJ, Stein DJ, Thomas K, et al. Cocaine abuse in the parturient: What are the anesthetic implications? Anesthesiology 1993; 79:A988 (abstr).
2. Castles A, Adams EK, Melvin CL, et al. Effects of smoking during pregnancy. Am J Prev Med 1999; 16:208-15.
3. Centers for Disease Control and Prevention. Prescription painkiller overdoses: a growing epidemic, especially among women. Atlanta, GA: Centers for Disease Control and Prevention; 2013. Available from http://www.cdc.gov/vitalsigns/prescription In killeroverdoses/index.html. Accessed January 25, 2017.
4. Hernandez M, Birnbach DJ, Van Zundert AA: Anesthetic management of the illicit-substance-using patient. Curr Opin Anaesthesiol 2005; 18:315–24.
5. McCalla S, Minkoff HL, Feldman J, et al. Predictors of cocaine use in pregnancy. Obstet Gynecol 1992; 79:641-644.
6. Meyer M, Wagner K, Benvenuto A, Plante D, Howard D. Intrapartum and postpartum analgesia for women maintained on methadone during pregnancy. Obstet Gynecol 2007; 110(2 Pt 1):261–6.
7. Nezvalová-Henriksen K, Spigset O, Nordeng H. Effects of codeine on pregnancy outcome: Results from a large population-based cohort study. Eur J Clin Pharmacol 2011; 67:1253–61.
8. Pattinson KT: Opioids and the control of respiration. Br J Anaesth 2008; 100:747–58.
9. Pinto SM, Dodd S, Walkinshaw SA, Siney C, Kakkar P, Mousa HA. Substance abuse during pregnancy: Effect on pregnancy outcomes. Eur J Obstet Gynecol Reprod Biol 2010; 150: 137–41.
10. Spence MR, Williams R, DiGregorio Gl, et al. The relationship between recent cocaine use and pregnancy outcome. Obstet Gynecol 1991; 78:326-329.
11. Stromer W, Michaeli K, Sandner-Kiesling A: Perioperative pain therapy in opioid abuse. Eur J Anaesthesiol 2013; 30:55–64.
12. Towers CV, Pircon RA, Nageotte MP, et al. Cocaine intoxication presenting as preclampsia and eclampsia. Obstet Gynecol 1993; 81:545-547.
13. Tran TH et al. Methadone, Buprenorphine, and Naltrexone for the treatment of Opioid Use Disorder in Pregnant Women Pharmacotherapy 2017;37(7):824–839) doi: 10.1002/phar.1958