Protective Effects Of Targeted Intra-arterial Injection Of Low Temperature Liquid On The Deep-Partial Thickness Scald Of Rabbit Hind Limbs

[Objective]To investigate the cooling and protective effects of a new modality:Low temperature Liquid(0-4℃) was intra-arterial injected 30mins to 60 mins after deepⅡscald of rabbits hind limbs through femoral artery,examined the cooling and protective effects and study the machnism of this method,hoping to offer a new clue of burn first aid cooling therapy,especially for the patients who suffered deep burns of limbs and regarded as the cases unsuitable for cooling treatment up to date.[Methods]120 New Zealand white rabbits wereused in this experiments.After anesthetigation,,standardized deep second degree scald of rabbit's hind limbs with TBSA 18%were made with the hind limbs immersed in 70℃water for 10 seconds and grouped into five groups randomly.GroupⅠand 2,20ml Low temperature liquid(4.0±0.8℃) was injected with 1 ml per second through femoral artery targetedly to cool the injured limbs 30mins and 60 mins postburn respectively;Group 3 and 4,HD-L type hydrogel dressing(?) was applied on the injuried limb 30mins and 60mins repectively;Group 5 as control and on treatment post burn.Subcutaneous and deep tissue temperatures of all wounds were monitored and recorded with we designed sepical temperature meter.Pre-scald during scalding and after scalding at regular intervals for 6 hrs post burn.The skin blood perfusion of each injured limbs was detected and recorded by Laser Doppler Perfusion Imagein(LDPI) and B-mode ultrasonic echo.The wound healing time and quality were observed and recorded.the specimens of the wounds were harversted for histological assessment and SEM(Scaning Electron Microscopy) examination.[Results]Effective cooling of the burn wound and an increased rate of wound healing was showed in both cooling methods.There are obviously significanct decreases(2.8±0.3℃) in artery injection groups than hydrogel groups decrease (1.3±0.4℃).While there is no obviously difference in both groups of subcutaneous temperature decreasing.LDPI and B-mode ultrasonic echo results show femoral artery injection and hydrogel dressing can obviously decrease the blood perfusion of skin especially in 30min group.Histological assessment at 21 days indicated more rapid healing in both the hydrogel dressing and artery injection burns compared with the controls group.The time of wound healing of treatment groups was earlier for 5±1days than that of control group.Hair growth appeared in each group.[Conclusion]This result indicates that for patients with burn injuries and traditional regarding as unfit for cooling treatment,artery injection of low temperature liquid within 30min to cool limb may be a potential new and effective means to reduce tissue damage and increase wound healing...