Neonatal Abstinence Syndrome

Neonatal abstinence syndrome (NAS) describes withdrawal signs in a newborn after antenatal exposure to a substance. Neonatal opioid withdrawal syndrome (NOWS) is the more specific term when opioids are the cause. Opioids are the substance class most often associated with a neonatal withdrawal state that requires a management plan. The newborn's presentation can involve the neurologic, gastrointestinal, respiratory, and musculoskeletal systems. A useful mental model is loss of an ongoing exposure after birth. A body that has adapted to a regular substance supply can develop withdrawal when that supply stops. In an opioid-exposed newborn, the resulting dysregulation can disturb wakefulness, muscle tone, feeding, sleep, consolability, breathing, temperature control, and weight gain. Severity varies with the substance or substances involved, exposure timing and frequency, metabolism, and gestational age. Exposure history establishes risk; the newborn's function and serial clinical findings determine the care required. The first bedside priority is physiologic stability, not completion of a withdrawal score. Assess airway, breathing, circulation, temperature, feeding ability, level of alertness, and overall appearance. Withdrawal-like findings are not specific. Hypoglycemia, hypocalcemia, central nervous system injury, hyperthyroidism,...