Symptoms of Neonatal Abstinence Syndrome

Signs and symptoms of Neonatal Abstinence Syndrome (NAS) usually begin anywhere within 24 hours to 7 days after birth depending on what substance was used by the mother.

The Neonatal Abstinence Syndrome Scoring System (click here) lists signs and symptoms that are monitored to score the severity of NAS. The percentage of infants that experience specific symptoms is poorly reported as research on this condition has only recently received focused attention. However, more severe symptoms have been more closely monitored and it is reported that 2-11% of infants with NAS experiencing seizures and over 30% experiencing ECG abnormalities.While individual infant responses to NAS may vary on the type(s) of drugs used by the mother, some of the most common include tremors, irritability (difficulty being comfortable), excessive crying, high pitched crying, sleep problems, vomiting, diarrhea and poor feeding (Hudak, Tan, The Committee on Drugs, & The Committee on Fetus and Newborn, 2012). Below are video examples of some of these common symptoms.

Tremors - these are sometimes mistaken as shivering, but notice the infants often pull their hands to their mouths while their legs show a kicking action.

Cry- While all babies cry, the NAS cry is very distinct because it is usually high-pitched and often occurs even when the babies are being consoled by swaddling, feeding, or holding. 

Overall, these symptoms show that infants experiencing NAS suffer greatly during their withdrawal. The majority of these symptoms can have dangerous effects on the infant. Decreased sleep, ineffective feeding, seizures, fever, abnormal respiratory rate, vomiting and diarrhea all can have severe negative outcomes for the infant as they begin the first few days of their new life. As was mentioned in earlier posts, most infants diagnosed with NAS end up staying in the NICU during recovery, and their length of stay is on average longer than infants who stay in the NICU for other reasons (Tolia, Patrick, Bennett, Murthy, Sousa, Smith, Clark, & Spitzer, 2015). Supervised recovery under the care of medial professionals is the only safe way to help an infant through these dangerous symptoms. Next week's blog will go into more detail on what NAS recovery looks like.

References

Hudak, M., Tan, R., The Committee on Drugs, & The Committee on Fetus and Newborn. (2012) Neonatal drug withdrawal. Pediatrics, 129(2), 540-560. doi: 10.1542/peds.2011-3212

Tolia, V., Patrick, S., Bennett, M., Murthy, K., Sousa, J., Smith, B., Clark, R., & Spitzer, A. (2015). Increasing incidence of the neonatal abstinence syndrome in U.S. neonatal ICUs. The New England Journal of Medicine, 372(22), 2118-2126.

Diagnosing Neonatal Abstinence Syndrome

Neonatal Abstinence Syndrome is identified and diagnosed through the use of several tools including clinical presentation scoring, maternal history, and toxicology screening of tissue samples.

Figure 1. Neonatal Abstinence Scoring System.

Clinical Presentation
After birth during the first few hours/days of life, a newborn is frequently assessed by nurses, pediatricians and other medical professionals. While there are many expected behaviors from newborns such as crying, fussing, acting hungry, etc. there are some behaviors that are abnormal and may mean there is a problem. Signs and symptoms of NAS will be further discussed in another blog post, but a scoring system (Figure 1) is used to standardize documentation of

concerning behaviors that may indicate NAS (Hudak, Tan, The Committee on Drugs, & The Committee on Fetus and Newborn, 2012).

Maternal History
Questions and information about drug use history is part of almost every single hospital admission assessment. Questions about current drug use, past drug use, and drug use by partners, family, and friends are all included in an intake assessment of the mother. However, drug use is frequently under-reported so clinicians also take into account a history of unexplained term fetal demise, severe mood swing, and inconsistency in prenatal care. Additionally, toxicology screenings are done if there is suspicion of drug use based on clinical presentation or history (Hudak, et al, 2012).

Figure 2. Urine Drug Screening 

Toxicology Screenings
There has been a movement to increase the analysis of the baby’s meconium (first bowel movement) to screen for drug substances. This method of screening provides a more longitudinal look at what kinds of substances might have been used even showing substances that were used as early as the second trimester. Baby and mother urine drug screenings are extremely popular but they usually only detect substances used within the last 24-72 hours. Additional samples can be taken from maternal hair, neonatal hair, and even umbilical tissue. These are less popular because of the relatively new technology required to perform and process the screening (Murphy-Oikonen, Montelpare, Southon, Bertoldo, & Persichino, 2010).

There are many factors that contribute to the diagnosis of NAS, and medical professionals are extremely careful to use a range of objective and subjective data to confirm this diagnosis. 

References

Hudak, M., Tan, R., The Committee on Drugs, & The Committee on Fetus and Newborn. (2012) Neonatal drug withdrawal. Pediatrics, 129(2), 540-560. doi: 10.1542/peds.2011-3212

Murphy-Oikonen, J., Montelpare, W., Southon, S., Bertoldo, L., Persichino, N. (2010). Identifying infants at risk for neonatal abstinence syndrome: A retrospective cohort comparison study of 3 screening approaches. Journal of Perinatal & Neonatal Nursing, 24(4), 366-372. doi: 10.1097/JPN.0b013e3181fa13ea

Figure 1 retrieved from http://img.medscape.com/pi/emed/ckb/pediatrics_cardiac/973235-978492-156.jpg 

Figure 2 retrieved from https://www.premierintegrity.com/Images/Protocols_445.jpg

Disease Process of Neonatal Abstinence Syndrome

The exact cause of Neonatal Abstinence Syndrome is the sudden discontinuation of infant exposure of to substances that were used by mothers during pregnancy. The most common substance that causes NAS is opioids such as heroin, codeine, oxycodone, methadone, or buprenorphine. Birth initiates the cessation from whatever substance is being used by the mother and allows the onset of a dangerous withdrawal period.

Figure 1. Transfer of opioids across the placenta 

(Neonatal Abstinence Syndrome, 2010).

The pathophysiology of NAS is not completely understood, but it definitely involves multiple body systems and could have still unknown effects on the long-term health and quality of life of the infant. The drug substance makes its entry into the bloodstream of the newborn via the placenta (Figure 1). Opiates are water soluble, low molecular weight substances that can easily cross this otherwise protective barrier between the bloodstream of the mother and fetus. As the fetus grows and demands more nutrients from mom, this transfer of opioids increases.

Figure 2. Mechanism of opioid withdrawal in neonates (Kocherlakota, 2014)

All opioids act primarily on opioid receptors in the central nervous system, peripheral nervous system, and the gastrointestinal system among others. As the substance abuse continues throughout birth, the fetus's body becomes accustomed to this receptor stimulation. When the stimulation of these opioid receptors is abruptly stopped by birth, a chain reaction is triggered in the newborn body. 

The absence of opioids triggers the production of norepinepherine, acetylcholine and corticotrophin. Additionally, the production of dopamine decreases during this withdrawal period. The ability of the autonomic and peripheral nervous systems and the gastrointestinal system to work properly is also affected after extended exposure to the opioids. See a complete diagram explaining the cascade to the left (Figure 2). Next week's blog will discuss how these different neurotransmitter and hormone changes cause dangerous responses in the newborn. 

References

Kocherlakota, P. (2014). Neonatal Abstinence Syndrome. Pediatrics, 134(2), 547-561. doi: 10.1542/peds.2013-3524. 

Neonatal Abstinence Syndrome. (2010). Retrieved from http://images.walgreens.com/marketing/library/contents.jsp?docid=19888&doctype=2