28: Substance Abuse and the Human Immunodeficiency Virus

INTRODUCTION

The prevalence of substance abuse in women of reproductive age has increased markedly over the past 20 years. Thus, it is likely that an anesthesiologist will encounter a pregnant woman who abuses illicit drugs.¹ A combination of drug abuse and related social ills can lead to poor fetal outcomes and serious maternal morbidity or even mortality.² Anesthesiologists are likely to first meet drug-abusing parturients in an acute setting, either when labor analgesia is requested or in an emergency situation such as fetal distress, placental abruption, uterine rupture, or sudden onset of maternal dysrhythmias. These women often have not had the benefit of prenatal care. Risk factors associated with drug abuse include lack of prenatal care, history of premature labor, and cigarette smoking.³ The possibility of drug abuse should also be considered if there is an unanticipated untoward reaction to an otherwise routine anesthetic.

Polysubstance abuse is common among drug abusers. It has been estimated that 50% of unregistered patients admitted to labor and delivery test positive for cocaine and that 25% of these patients also test positive for other drugs.⁴ Complication rates are significantly higher when drugs are used in concert than when one drug is used alone.⁵ When interviewed by anesthesiologists or obstetricians, drug-abusing parturients will most likely not be forthcoming about their addiction. However, the most common cause of failure to diagnose drug abuse is a failure to ask. The American College of Obstetricians and Gynecologists (ACOG) recommends that a drug history be obtained from all patients. In addition, ACOG advocates that support, aid, and counseling be made available to all women who acknowledge substance abuse. The role of caregivers should be to focus on prevention and treatment rather than punitive measures against the mother. Routine drug testing in patients with a history of drug abuse should be considered as a method to encourage abstinence.¹

COCAINE

Cocaine abuse continues to be a major problem affecting society. Although it is difficult to estimate the prevalence of cocaine use in parturients, its use appears to be on the rise. In 2008, 772,000 adolescents and adults reported first-time cocaine use.

Diagnosing the cocaine-abusing parturient poses unique challenges because the hallmarks associated with cocaine use—tachycardia, hypertension, and dysrhythmias—may also be confused with cardiac responses to normal labor. In addition to the cardiovascular symptoms, other signs of cocaine use are seizures, hyperreflexia, fever, dilated pupils, emotional instability, proteinuria, and edema. Cocaine-induced hypertension, seizures, and proteinuria can be mistakenly diagnosed as preeclampsia-eclampsia. The differential diagnosis is usually aided by toxicology screening. Most commonly, cocaine metabolites are tested for in maternal urine and can be detected for up to 60 hours after use. A rapid latex agglutination test can detect urine cocaine metabolites within a few minutes, and this test can be performed easily at the bedside in labor and delivery or in an emergent situation. ...