This study was undertaken to investigate the effects of blood flow rate and heparin dosage on blood clot formation of extracorporeal circulation on hemodialysis in dogs. Six healthy dogs of 11-23 kg body weight were anesthetized with pentobarbital-sodium, and single-lumen catheters were inserted temporarily into bilateral external jugular veins. Experiment I had the constant blood flow rate (30 mL/min) with three different heparin regimens (40 U/kg+30 U/kg/hr, 70 U/kg+50 U/kg/hr, 100U/kg+70 U/kg /hr). Experiment II had one heparin regimen (70 U/kg+50 U/kg /hr) with two different blood flow rate regimens (30 mL/min, 100mL/min). Hemodialysis was performed when the dogs were recovered from anesthesia. Each session lasted for 3 hours. The results revealed increased heparin regimens can significantly prolong APTT values (100 U+70 U > 70 U+50 U>40 U+30 U. p <0.01) from the arterial and venous sides of the blood tubing set, and there were no significant differences (p> 0.05, n=5) of the residual dry blood weights within the dialyzer in experiment I. However, many blood clots were found in the chambers of the blood tubing set that was used in one dog with low heparin regimen (40 U +30 U), no blood clots were observed in the blood tubing set used in both blood flow rate regimens (30 mL/min, 100 mL/min). Nevertheless, higher blood flow rate did result in less residual dry blood weight (p < 0.01, n=4), though the APTT values (100 mL/min) from the venous side of the blood tubing set were lower significantly than 30 mL/min regimen (p<0.05). Based on the results, we conclude that appropriate heparin dosage and increasing of blood flow rate can reduce clot formation in extracorporeal circulation on hemodialysis in dogs.
This study was undertaken to investigate the effects of blood flow rate and heparin dosage on blood clot formation of extracorporeal circulation on hemodialysis in dogs. Six healthy dogs of 11-23 kg body weight were anesthetized with pentobarbital-sodium, and single-lumen catheters were inserted temporarily into bilateral external jugular veins. Experiment I had the constant blood flow rate (30 mL/min) with three different heparin regimens (40 U/kg+30 U/kg/hr, 70 U/kg+50 U/kg/hr, 100U/kg+70 U/kg /hr). Experiment II had one heparin regimen (70 U/kg+50 U/kg /hr) with two different blood flow rate regimens (30 mL/min, 100mL/min). Hemodialysis was performed when the dogs were recovered from anesthesia. Each session lasted for 3 hours. The results revealed increased heparin regimens can significantly prolong APTT values (100 U+70 U > 70 U+50 U>40 U+30 U. p <0.01) from the arterial and venous sides of the blood tubing set, and there were no significant differences (p> 0.05, n=5) of the residual dry blood weights within the dialyzer in experiment I. However, many blood clots were found in the chambers of the blood tubing set that was used in one dog with low heparin regimen (40 U +30 U), no blood clots were observed in the blood tubing set used in both blood flow rate regimens (30 mL/min, 100 mL/min). Nevertheless, higher blood flow rate did result in less residual dry blood weight (p < 0.01, n=4), though the APTT values (100 mL/min) from the venous side of the blood tubing set were lower significantly than 30 mL/min regimen (p<0.05). Based on the results, we conclude that appropriate heparin dosage and increasing of blood flow rate can reduce clot formation in extracorporeal circulation on hemodialysis in dogs.