Evaluation of silver coated hemostatic dressing to control hemorrhage in a porcine model of lethal vascular injury.

THE AIM OF THE STUDY

An ideal hemostatic dressing that would control bleeding and protect the wound from further contamination is still being sought for combat casualty care. The new SilverLeaf™ (SL) bandage was made of material containing active hemostatic property and possible antimicrobial property from silver coating. This study was conducted to compare and ascertain the hemostatic properties of SL and compare it with known hemostatic dressings: Combat Gauze® (CG) and WoundStat™ (WS) in a swine model with punch, vascular injury.

MATERIAL AND METHODS

Three hemostatic dressings were evaluated in anesthetized Yorkshire swine hemorrhaged for 45 sec in a femoral arterial puncture model. The hemostatic dressings SL, CG, or WS were applied on an actively bleeding wound, followed by 5 minutes of compression at 200 mm Hg. The pressure was then released to baseline and skin closed with towel clamps. After 15 minutes, 500 ml of (Hextend) resuscitation fluid infused over a period of 30 minutes. The animal's vital signs were monitored for the 3-hour experiment period. Primary outcomes documented were incidence of bleeding after application of the dressing, restoration of MAP and rate of survival.Results. The pre-treatment blood loss for WS was 375.66 ml (16.49%), SL 282.08 ml (12.15%) and CG 307.24 ml (12.68%) and was comparable between groups (p>0.56). The post-treatment blood loss for WS was 286.05 ml (10.65%), SL 386.81 ml (16.92%), and CG 525.76 ml (21.52%). There was no significant difference in post-treatment blood loss (p>0.37) between groups. The Mean Arterial Pressure (MAP) did not significantly differ between the groups at all time points compared. The SL and CG had comparable MAPS during the first hour. The SL had a slight advantage, but didn't reach statistical significance. This suggests that all the bandages were comparable. The two time points at which the post-treatment bleeding occurred in the three groups after the release of manual compression and after restoration of blood pressure. The post-treatment re-bleeding rates were 22.22% (2/9) for WS and SL, 44.44% (4/9) for CG. The survival rates were 100% for WS, 88.89% for SL, and 77.78% for CG.

CONCLUSION

The findings indicate that SilverLeaf, WoundStat and Combat Gauze were comparable in controlling bleeding, preventing re-bleeding, maintenance of mean arterial pressure and improving survival following treatment.