Effects of infection on oxygen consumption and core temperature in experimental thermal injury

Oxygen consumption (V̇O₂) and colonic temperature (T(c)) were measured in groups of rats and after 30% total body surface, full thickness burns. Some wounds were seeded with Pseudomonas aeruginosa or Staphylococcus epidermidis, and some seeded wounds were treated with Sulfamylon® or Silvadene®. Three groups became bacteremic (B) during the 2-3 week period of observation. At an ambient temperature (T(a)) of 32 C, V̇O₂ of the B groups rose from 0.83 ± 0.01 to 1.20 ± 0.01 ml/hr/g (mean ± S.E., p < 0.001) versus 0.81 ± 0.01 to 0.99 ± 0.02 for nine nonbacteremic (NB) groups (p < 0.001). T(c) increased only in the B groups - from 36.8 ± 0.1 to 37.7 ± 0.1 C (p < 0.001). In the second or third week postinjury, V̇O₂ of the NB rats was reduced when T(a) was increased to 34 C; T(c) followed changes in T(a). Sulfamylon lowered V̇O₂ of P. aeruginosa seeded, NB rats. The metabolic cost of wound contamination appeared to vary with bacterial strain. The metabolic effects of infection appear to be a continuum, beginning with a modest rise in V̇O₂ and progressing to greater increases in V̇O₂ and T(c) with wound invasion and systemic infection.