Ketamine is one of the recommended anesthetics in pediatric septic shock [17] [18] [19] , which is frequently caused by staphylococci [12, 20] . The reasoning for ketamine's use in staphylococcal septic shock is its blood pressure supporting effect. It increases cardiac output and blood pressure, possibly via a catecholamine release mechanism [17, 21] . Some data suggest that ketamine has anti-inflammatory effects [22] [23] [24] [25] . For example, it has been reported that ketamine suppresses macrophage TNF secretion in response to Gram-negative bacterial LPS in vivo and in vitro [22, 23, 25] . There is also one report that ketamine suppresses TNF production by human whole blood in vitro after exposure to staphylococcal enterotoxin B [24] . The mechanisms responsible for the anti-inflammatory effects of ketamine are not known [22] [23] [24] [25] .The present study examined the hypothesis that ketamine could suppress macrophage TNF production in response to whole bacteria, in this case clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA). Given the important role of TNF in sepsis [26] [27] [28] [29] , and the importance of staphylococcal sepsis in children, such suppression could have a therapeutic impact.