Which of the following in anesthesia will produce decreased EEG activities
A i.e. Hypothermia Hypothermia causes progressive slowing of brain activity at core temperatures below 35degC. Severe hypothermia (progressive decrease in EEGQ. Situation Effect On EEG - Hypothermia (<35degC) Progressive slowing of EEGQ - Profound hypothermia (7- 20degC) Complete electrical silent CO2 level - Hypocarbia - Slowing of EEG - Hypercarbia (5-20%) - Decreased cerebral excitability & increased electroshock seizure threshold - Hypercarbia (>30% above normal) - Increased cerebral excitability & epileptiform discharge - Hyper carbia (>50% above normal) - EEG depression. 02 levels - Hyperoxia - Cerebral excitation 1/t low amplitude fast frequency EEG - Early thypoxia - Cerebral excitability (d/t peripheral cemoreceptor stimulation) - Persistent Hypoxia Vt. acute increase in amplitude of EEGQ - Late Hypoxia approching anoxia - Diffuse slowing of EEGQ Vt marked reduction in amplitude with appearance of slow wavesQ - EEG silence Sensory stimulation (in awake) Desynchronization of EEG patterns, increased amplitude, and increased frequency. Narcotic Analgesics - Low dose - Increase amplitude of both a & p bands. - High dose - Theta & delta frequencies develop heralding the onset of sedation Enflurane Dose dependent depression of EEG activity, but at moderate high concentration (>3%), it produces epileptiform paroxymal spike activity and burst suppressionQ. It should be avoided in epileptic patientsQ. - No seizure activity on EEG & excitatory effects (as seen in Isoflurane, Desflurane and enflurane) ) - Dose dependent depression of EEG activity Sevoflurane - Does not cause seizure activity at any level of anesthesia with or without hypocapnia. Propofol - EEG frequency decreases & amplitude increase Ketamine - Unlike those seen with other IV. anesthetics, and consists of loss of alpha rhythm and predominant theta activityQ.
Hypothermia
Early Hypoxia
Ketamine
N20