Childhood Anesthesia and Cognitive Function

Contrary to a longstanding belief, anesthesia has lasting effects on the neonatal brain. In rats anesthesia causes death of brain cells, ill-timed conversion of stem cells to nerve cells and a certain kind of brain defect up to 8 months later. This brain defect is called a hippocampal deficit because it resembles the type of defect that people have when a structure in the brain called the hippocampus has been injured, removed or is no longer functioning. However, to date it is unknown if anesthesia given to human infants causes a lasting hippocampal deficit, which might manifest itself as memory problems and academic failure despite normal intelligence. The investigators will test the hypothesis that anesthesia for more than 2h given to children of less than 2 years of age without coexisting diseases of the brain or the heart causes long-term impairment of hippocampal function. Using state of the art hippocampal and general brain function testing the investigators will compare hippocampal dependent and hippocampal independent memory as well as general cognitive function and emotional state in 10 year-old children that underwent at least a 2h anesthetic at less than 2 years with that of a matched control group that did not undergo an anesthetic.

Inclusion criteria

• Anesthesia at less than 2 years of age
• Anesthetic time greater than 2 hours
• ASA I or II
• Induction with Propofol or Sevoflurane +/- N2O
• Maintenance with a volatile agent (sevoflurane, isoflurane, desflurane) +/- N2O

Exclusion criteria

• Neurosurgery
• Known genetic syndrome
• Any other anesthetic agents (ketamine, meperidine, barbiturates, etomidate, methoxyflurane, methadone, lorazepam)
• Low birthweight (<25%ile)
• Gestational age , 36 weeks
• color blindness
• h/o CNS disease
• cancer
• head trauma
• congenital heart disease
• ASA III or IV
• intra-operative hypotension (<30% baseline for > 5 min)
• Bradycardia (<30% baseline for > 5 min)
• Hypoxemia (Blood Oxygen Saturation <93% for > 5 min)
• Hypercarbia (pCO2 > 60 mm Hg > 5 min)
• Dysthermia (deviation from 36.5 deg C by > 1.5 deg C at any time)
• Puberty