assessment Queensland Clinical Guideline: Perinatal substance use: neonatal Refer to online version, destroy printed copies after use Page 9 of 33 3 Assessment Suspect NAS and investigate to determine diagnosis in any baby who displays signs of NAS. 3.1 Signs NAS Clinical presentation can be non-specific and variable in intensity and duration. Additionally, similar signs can occur across all substance classes and this is compounded when there is maternal polysubstance use. There may also be no signs of withdrawal. Table 5. Signs of NAS Signs7,34-36 Substances implicated Neurotransmitter7,34,35 • Sleeping problems • Opioids • TCA • SSRI • SNRI • Methamphetamines • Alcohol* • Decreased serotonin • Poor feeding • Hypertonia • Jitteriness • SSRI • SNRI • Increased serotonin • Hyperirritability • Opioids • Methamphetamines • Inhalants • Nicotine* • Alcohol* • Decreased dopamine • Hyperphagia • Increased stress • Opioids • Increased corticotrophin • Hyperthermia • Hypertension • Tachycardia • Tremors • Opioids • SSRI • SNRI • Alcohol* • Increased noradrenaline • Sweating • Vomiting • Diarrhea • Yawning • Sneezing • Sleeping problems • Opioids • TCA • SSRI • SNRI • Alcohol* • Increased acetylcholine • Jittery • Irritability • Benzodiazepines • Barbiturate • Solvents • Caffeine • Increased GABA (gamma aminobutyric acid) *Multiple or unknown/uncertain neurotransmitter involvement37 Queensland Clinical Guideline: Perinatal substance use: neonatal Refer to online version, destroy printed copies after use Page 10 of 33 3.2 Clinical assessment Table 6. Clinical assessment Aspect Consideration Clinical examination • Review maternal and newborn history and relevant pathology • Conduct a full newborn examination to exclude differential diagnoses, even if known maternal substance use • Consider concurrent illness • Review risk factors for neonatal sepsis • Investigate as required to exclude infection or metabolic disturbances • Treat identified illness Substance testing • Routine testing not recommended1 • Perform only where results will inform clinical management • If testing is indicated, discuss with parent/carer and gain consent prior to specimen collection • Pathology Queensland recommend: o Urine is the sample of choice o Plasma if urine unavailable o No validated method for screening meconium but testing may be possible if required 3.3 Differential diagnosis NAS may be difficult to differentiate from other neonatal conditions. Consider other diagnosis because many babies with NAS are at elevated risk of infections and other comorbidities. Table 7. Differential diagnosis Specific NAS sign Differential diagnosis28 Irritability • Gastro-oesophageal reflux • Pain/discomfort • Sepsis • Brain injury Fever • Sepsis (especially herpes simplex virus) • Hyperthyroidism Feeding problems • Oromotor dysfunction • Anomalies (e.g. cleft palate, micrognathia, Pierre Robin sequence, genetic syndromes such as Prader Willi) • Polycythaemia • Immaturity, including late preterm birth • Jaundice • Brain injury • Sepsis Jitteriness • Hypoglycaemia • Hypocalcaemia • Immaturity • Injury of the nervous system Myoclonic jerking • Not uncommon in opioid-exposed infants and can be mistaken for seizure activity Seizures (rare with NAS) • Hypocalcaemia • Hypoglycaemia • Hypoxic-ischemic encephalopathy • Brain haemorrhage/stroke • Meningitis • Inborn errors of metabolism • Seizure disorders Queensland Clinical Guideline: Perinatal substance use: neonatal Refer to online version, destroy printed copies after use Page 11 of 33 3.4 Assessment tools A variety of assessment tools and methods have been reviewed for usefulness in clinical practice, but high quality evidence remains limited.18 Consistent use of a preferred assessment tool at the facility level promotes familiarity, and consistency of decision making and supports quality data collection and outcome reporting. Tools for assessment of NAS aim to provide objective data about: • Requirements for additional monitoring and care • When to commence pharmacological treatment • Whether a medication dose requires alteration • Resolution of signs 3.4.1 Finnegan neonatal abstinence severity score Table 8. Finnegan neonatal abstinence severity score Aspect Consideration Context • Most widely used38,39 and the Australian standard for assessment of opioid withdrawal in term babies • Has been used (but not validated) to assess signs of non-opioid related NAS8 o Benzodiazepines and alcohol o Neonatal stimulant intoxication o SSRI and SNRI40 Benefits and limitations • Common in clinical practice in Australia • Requires initial and repetitive training to obtain inter-rater reliability • Assessment of some criteria (e.g. Moro reflex) requires baby to be disturbed which may inflate FNAS • Focuses on achieving a FNAS of less than eight • Not validated for preterm babies • May prompt earlier or later initiation and greater intensity of pharmacological treatments Elements • Assesses and allocates a FNAS to 21 signs of withdrawal across three main elements (systems) o Central nervous system o Gastrointestinal o Vasomotor and respiratory Assessment protocol41 • Assess elements half to one hour after each feed o FNAS reflects behaviour since the previous assessment averaged over three to four hours • Make allowances for babies who are preterm or beyond the initial