Anesthesia management of neonates and infants requiring intraoperative neurophysiological monitoring: A concise review

Abstract

Intraoperative neurophysiological monitoring is currently used to prevent intraoperative spinal cord and nerve injuries during neonatal and infant surgeries. However, its use is associated with some issues in these young children. The developing nervous system of infants and neonates requires higher stimulation voltage than adults to ensure adequate signals, thereby necessitating reduced anesthesia dose to avoid suppressing motor and somatosensory-evoked potentials. Excessive dose reduction, however, increases the risk of unexpected body movement when used without neuromuscular blocking drugs. Most recent guidelines for older children and adults recommend total intravenous anesthesia with propofol and remifentanil. However, the measurement of anesthetic depth is less well understood in infants and neonates. Size factors and physiological maturation cause pharmacokinetics differences compared with adults. These issues make neurophysiological monitoring in this young population a challenge for anesthesiologists. Furthermore, monitoring errors such as false-negative results immediately affect the prognosis of motor and bladder-rectal functions in patients. Therefore, anesthesiologists need to be familiar with the effects of anesthetics and age-specific neurophysiological monitoring challenges. This review provides an update regarding available anesthetic options and their target concentration in neonates and infants requiring intraoperative neurophysiological monitoring.

Keywords: evoked potentials; infants; intraoperative neurophysiological monitoring; neonates; pharmacodynamics; pharmacokinetics; spinal instrumentation; total intravenous anesthesia.