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respected authorities based on clinical experiences, descriptive studies, case reports, or reports of experts. Two articles were Level I-II – experimental studies. Results of the review showed that traditional supportive interventions also have a body of evidence for their use. Although there is much research regarding neonatal abstinence syndrome (NAS), the majority of future research needs to be at a higher level of evidence. Nursing applications include obtaining evidence for best practice through diligent searches of the literature and expert guidelines. Evidence-Based Interventions For Neonatal Abstinence Syndrome Nancy J. MacMullen, Laura A. Dulski, and Paul Blobaum Objectives and instructions for completing the evaluation and statements of disclosure can be found on page 172. Nancy J. MacMullen, PhD, APN/CNS, RNCHROB, CNE, is an Associate Professor, Governors State University, Department of Nursing, University Park, IL. Laura A. Dulski, MSN, APN/CNS, RNCHROB, CNE, is an Assistant Professor, Resurrection University, School of Nursing, Chicago, IL. Paul Blobaum, MA, MS, is a Full Professor and Library Liaison to Nursing, Governors State University, University Park, IL. Drugs and Crime (UNODC) reported that approximately 3.6% to 6.9% of the world’s population 15 to 64 years of age abused illicit drugs at least once in the previous year (UNODC, 2013). In the United States, 5.9% of pregnant women 15 to 44 years of age used illicit drugs during the past month (Substance Abuse and Mental Health Administration [SAMHSA], 2012). Infant/Neonatal Incidence In the United States, approximately 225,000 infants yearly are exposed to illicit substances (Keegan, Parva, Finnegan, Gerson, & Belden, 2014). The prevalence of prenatally exposed newborns to one or more illicit drugs averages approximately 5.5%, with a range of 1.3% to 50% (Wang, 2014). Greater than 75% of infants exposed to drugs have major medical problems, compared with 27% of unexposed infants. Seventeen percent of drug-exposed versus 6% of unexposed babies are delivered prematurely (Huestis & Choo, 2002). Cost In addition to the personal costs in relationships, health, and the future development of neonates with NAS, there is a financial cost as well. It is common for neonates with NAS to experience longer stays in the hospital than NAS-free neonates (Oei & Liu, 2007). Data from the AHRQ Health - care Cost and Utilization Project (HCUP) Nationwide Inpatient Sample (2009) show that aggregate charges for substance-related disorders in the age category of less than one year were over 96 million dollars ($96,440, 575). The cost of keeping a drugexposed child in a neonatal unit is estimated at $2,700 per child per day (Cooper, 2004). Etiology There are two major types of NAS (Hamdan, 2010). The more recognized type is prenatal NAS, which is due to prenatal maternal use of substances. The abuse may result in withdrawal symptoms in the neonate once the placental access to the substance is no longer available. Drugs commonly implicated in prenatal NAS are opiates, barbiturates, cocaine, sedatives, ethan - ol, marijuana, and nicotine (Davison, Worsley, & Husband, 2007; Wang, 2010). Postnatal NAS results when an abrupt discontinuation of analgesia, such as Fentanyl or morphine, occurs usually after prolonged drug exposure for post-procedure pain management and/or sedation (Hamdan, 2010). The focus of this article is on prenatal NAS. 166 PEDIATRIC NURSING/July-August 2014/Vol. 40/No. 4 Pathophysiology Drugs are transferred from the mother to the fetus via the placenta. Huestis and Choo (2002) describe the mechanisms responsible for the transfer: active transport (requires energy to move fluids into the cell), passive diffusion (requires no energy for movement), and pinocytosis (moves fluids by invagination of cell membrane). The authors also report that the ease of transport depends upon the size of the drug molecule, its lipophilicity, the pKa (acid ionization constant) of the compound and the pH of the blood. At delivery, the transplacental passage of the drug is interrupted, resulting in the development of a withdrawal syndrome in the neonate (Oei & Liu, 2007). The pathophysiology and mechanisms of withdrawal are poorly understood (Jansson, 2008). It is theorized that withdrawal can cause molecular and cellular alterations that produce systemic, behavioral, and cognitive symptoms (Wang, 2010). Effects of Drugs On the Neonate Symptoms and length of withdrawal vary according to the amount and type of drug used. For example, cocaine withdrawal occurs over a short period of time, whereas opiates can produce a longer and more threatening withdrawal (Greene & Goodman, 2003). The effect of drugs on body systems is also influenced by the type of drug, the combination of drugs, the amount and frequency of use, the trimester in which the drug is used, the timing of withdrawal, and the genetic susceptibility of the fetus/ neonate (Oei & Lui, 2007; Sun, 2004). Withdrawal symptoms relate to the type of drug ingested (see Table 1) (Davison et al., 2007; Hamdan, 2010; Huestis & Choo, 2002; Oei & Lui, 2007; Wang, 2010).