Please see Bibliography of References for a list of abstracts, manuscripts and posters.

Hemorrhage

Noninvasive muscle oxygenation to guide fluid resuscitation after traumatic shock

Crookes BA, Cohn SM, Burton EA, Nelson J, Proctor KG. Surgery. 2004;135(6):662-670.

Background: Three different protocols tested the hypothesis that hind limbmuscle tirsue O₂saturation (SO₂), measured noninvasively with near-infrared spectroscopy (NIRS), isas reliable as invasive systemic oxygenation indices to guide fluid resuscitation.

Methods: In SeriesI, swine (n = 30) were hemorrhaged, then received eitherno fluid, a fixed volume of colloid (15 mL/kg),or shed blood plus lactated Ringer's (LR)titrated to MAP >60mm Hg.In series2, swine (n = 16) received a penetrating femur injury, a 47% to 55% hemorrhage to determine a median lethal dose (LD₅₀) then shed blood plus LR titrated to MAP>60 mm Hg.In series 3, swine (n = 5) received the femur injury plus LD₅₀ hemorrhage, and were resuscitated with LRtitrated to StO₂ >50%.

Results: In series 1, St0₂ tracked mixed venow O₂ saturation (SvO₂), but discriminated between 3 survivor groups better than SvO₂, arterial lactate, orarterial base excess. In series 2, StO₂ tracked SvO₂ but discriminated between 2 survivor groupsbetter than SvO₂, arterial lactate, or arterial base excess. In series 3, animals survived to extubation when resuscitated to an StO₂target.

Conclusions: Noninvasive muscle StO₂ determined byNIRS was more reliable than invasive oxygenation variables as an index of shock. Because muscle StO₂ can be easily monitored in emergencysituations, it mayrepresent an improved method to gauge the severity of shock or the adequacyof fluid resuscitation after trauma.