Purpose of review: There is now more than a decade of mounting animal data that anesthetic drugs can cause apoptosis during a critical period of brain development and that this correlates with later behavioral disturbances. Initial articles examining the effects of early anesthesia on human infants have recently been published. Prospective studies are underway.
Recent findings: Several retrospective studies in humans have been published over the last year using different methodologies. Although most raise some concern that anesthetic use in infants and young children may be problematic, all have inherent limitations in methodology that prevent clinicians from drawing firm conclusions regarding the risk of anesthesia on brain development in humans.
Summary: Although the evidence from animal studies is clear and continuing to mount that anesthetic drugs given at the right time and in sufficiently high and prolonged doses do cause increased neuronal apoptosis and later problems with learning, evidence in humans that this is of clinical concern is both weak and mixed. Additional studies are ongoing to try to better define the risk.