Which of the following in anesthesia will produce decreased EEG activities (AIIMS Nov 2009)
a. Severe hypothermia (<28°C)- CNS effects includes - loss of cerebrovascular autoregulation, decline in cerebral blood flow, coma, loss of ocular reflexes, PROGRESSIVE DECREASE IN EEG.
b. HYPOXEMIA - produces an acute increase in amplitude of EEG initially and then marked reduction in amplitude with the appearance of slow waves as hypoxemia worsens. (page 104, text book of anesthesia, Aitken head, 2nd edition)
c. KETAMINE - produces loss of alpha rhythm and predominant theta activity. The EEG picture with ketamine is unlike those seen with other IV anesthetics.