Microdialysis in the femoral head of the minipig and in a blood cloth of XXXX blood.

@entity1 @entity1707 @entity63 @entity653 @entity880 @entity413 @entity2388
INTRODUCTION: Microdialysis can detect @entity63 in soft tissue. In a previous study, we have shown the development of @entity63 in the femoral head removed from @entity1 undergoing total hip replacement. That study also raised some methodological questions that this study tries to answer: what is happening in the dead space around the catheter in the drill canal, and is there an equilibrium period after the insertion of the catheter? MATERIAL AND METHODS: In an ex-vivo study using 5 syringes with 5 mL @entity1 blood, a microdialysis catheter was inserted and microdialysis was performed over 3 h. In an in-vivo study, a drill hole was made in the proximal part of the femur in 6 mature G  ttingen minipigs and microdialysis was performed over 3 h. The @entity1707 were kept normoventilated during the experiment. RESULTS: The ex-vivo microdialysis results showed that @entity880 kept a steady level and @entity413 and @entity653 both fell; @entity2388 fell but leveled out. The mean @entity880 / @entity2388 ratio increased from 13 (SD 4) to 32 (SD 6) (p < 0.001). In vivo, relative recovery was 57% (SD 11). @entity880 increased, @entity2388 stayed constant, and @entity413 and @entity653 levels fell. The @entity880 / @entity2388 ratio increased from 30 (8) initially to 37 (8) after 1 h (p = 0.007) but no statistically significant change from 1 to 2 h was observed. INTERPRETATION: The ex-vivo study showed a clear washout pattern, and was different from what we see in bone. The in-vivo study indicated that an equilibrium period is necessary or that a reference measurement in healthy bone must be used when performing short measurements in bone.
