Simplified Neonatal Abstinence Tool May Identify Infants Who Need Treatment

By Marilynn Larkin

April 17, 2020

NEW YORK (Reuters Health) - A shortened version of the Finnegan Neonatal Abstinence Scoring Tool (FNAST) may simplify the assessment and management of infants experiencing opioid withdrawal, researchers suggest.

"The FNAST is a comprehensive but lengthy tool that is prone to scoring variability in the absence of extensive training," Dr. Lori Devlin of the University of Louisville School of Medicine in Kentucky told Reuters Health by email.

The simplified tool, she said, "focuses on a few key symptoms of opioid withdrawal that are strongly associated with the receipt of pharmacologic therapy. (It) looks for the presence or absence of eight key signs of withdrawal and is able to identify infants who qualify for pharmacologic therapy nearly as well as the original FNAST."

"Validation of our findings in an independent group of infants with neonatal abstinence syndrome supports the generalizability of this simplified tool and sets our findings apart from other shortened tools."

As reported in JAMA Network Open, Dr. Devlin and colleagues analyzed medical records for 424 neonates (51% female) with opioid exposure and a gestational age of at least 36 weeks (derivation cohort) and 109 neonates with opioid exposure from the Maternal Opioid Treatment: Human Experimental Research Study (validation cohort).

Convulsions were not observed in the derivation cohort, and high-pitched cry and the hyperactive Moro reflex had "extremely different" frequencies across cohorts, according to the authors. Therefore, they removed those FNAST items. In addition, they combined the two tremor items.

Further analysis revealed that eight of the remaining 17 items were independently associated with needing pharmacologic treatment, with an area under the curve of 0.86, compared with 0.90 for the 21-item FNAST.

The eight selected items are:

- Sleeps <3 h after feeding;

- Any tremors;

- Increased muscle tone;

- Body temperature of 37.2 C or higher;

- Respiratory rate >60 min;

- Excessive sucking;

- Poor feeding; and

- Regurgitation

In the validation cohort, the eight selected items resulted in an area under the curve of 0.86. Further, thresholds of 4 and 5 on the simplified scale yielded the closest agreement with FNAST thresholds of 8 and 12.

Dr. Devlin said, "The results of this study move us one step closer to a simplified clinical tool that will accurately identify infants who qualify for pharmacologic therapy for neonatal abstinence syndrome. The next step in this research is the development of prospective studies to establish clinical utility and determine validity and reliability of this simplified tool in comparison to other tools and approaches. Such studies are currently in development."

Dr. Ju Lee Oei of the University of New South Wales, in Sydney, coauthor of a related editorial, commented in an email to Reuters Health, "The Finnegan's score has been used for more than 40 years to provide an objective measure of withdrawal symptoms in newborn infants affected by intrauterine exposure to maternal opioids. It is a complex assessment tool and fraught with subjective differences."

"Its relevance to other problems - e.g., exposure to non-opioid drugs, prematurity, and importantly, to long-term outcomes like neurodevelopment or behavior - is unknown," she said. "A simplify the scoring system is well-meaning and may reduce human error, hospitalization and medications for neonatal abstinence syndrome, but again, its relevance to important outcome measures such as survival and neurodevelopment is unknown."

"I suggest priorities in neonatal abstinence syndrome research should focus on outcomes beyond the nursery, especially for neurodevelopment and behavioral disorders, which are highly prevalent in children with a history of (the syndrome)," she concluded.

SOURCE: and JAMA Network Open, online April 8, 2020.