The Neurologic and Adaptive Capacity Score: a systematic review of its use in obstetric anesthesia research.

THE Neurologic and Adaptive Capacity Score (NACS) was described in 1982 by Amiel-Tison et al. It was developed to evaluate the neurobehavior of term, healthy newborns; specifically, to detect central nervous system depression from drugs administered to the mother during labor and delivery and to differentiate these effects from those associated with perinatal asphyxia and trauma at birth. The 20-item instrument contains items from the Brazelton Neonatal Behavioral Assessment Scale (NBAS), the Scanlon Early Neonatal Neurobehavioral Scale (ENNS), and the Amiel-Tison Neurologic Evaluation. Several review articles have described these tests in detail and compared the NBAS and ENNS to the NACS. The NACS emphasizes muscle tone more than the ENNS and NBAS. It takes less time to complete without subjecting neonates to aversive stimuli such as pinpricks and repeated Moro maneuvers. The original article provided instructions on how to use the scale, outlining the appropriate testing environment, the state of the neonate at the time of testing, and the order in which to conduct the test items. Instructional text and photographs illustrated the correct technique for performing the assessments. The NACS items are organized into two scales: adaptive capacity and neurologic assessment. The latter is further divided into four subscales: passive tone, active tone, primary reflexes, and a general neurologic status assessment. Items are scored 0 (absent or grossly abnormal), 1 (mediocre or slightly abnormal), or 2 (normal), for a maximum score of 40. A score of $ 35 was arbitrarily deemed to be normal. The NACS has been used extensively for research purposes during the past 16 yr to evaluate the neurobehavior of neonates. We undertook this systematic literature review to examine how it has been used in obstetric anesthesia research and to determine whether there is evidence that it is a reliable and valid tool for detecting drug effects in neonates. In addition, we assessed whether the scale had been used as originally described, paying particular attention to the timing of the tests and the neonatal environment. This article is accompanied by an Editorial View. Please see: Camann W, Brazelton TB: Use and abuse of neonatal neurobehavioral testing. ANESTHESIOLOGY 2000; 92:3–5. r