Howe L M, Boothe D M, Boothe H W
Department of Small Animal Medicine, Texas Veterinary Medical Center, College of Veterinary Medicine, Texas A&M University, College Station 77843-4474, USA.
Am J Vet Res. 1997 Jan;58(1):83-8.
To document presence of endotoxin in portal and systemic blood in a model of canine multiple portosystemic shunts (PSS), and compare values in clinically normal dogs, before and after vena caval banding.
6 control dogs and 10 dogs with dimethylnitrosamine-induced multiple PSS that were subjected to vena caval banding.
Dimethylnitrosamine was administered orally (2 mg/kg of body weight, twice weekly) to the 10 dogs in the diseased group until multiple PSS developed. Surgery was then performed on all 16 dogs (both groups), and shunts were confirmed in the diseased dogs. Blood was collected from the portal vein, hepatic vein, and caudal vena cava baseline endotoxin determination and aerobic and anaerobic blood culturing. Baseline pressure measurements were taken from the portal venous catheter; then vena caval banding was performed. Blood for endotoxin determinations was taken from all vessels 20, 40, 60, 120, 240, and 360 minutes after banding; portal pressure measurements were taken at the same time as sample acquisition. Blood for culturing was taken from the portal and hepatic venous catheters at 120, 240, and 360 minutes after banding.
Dogs in the diseased group had significantly greater overall presence of endotoxin in the portal vein (P < or = 0.0002), hepatic vein (P < or = 0.0001), and caudal vena cava (P < or = 0.0004) than did control dogs. With respect to time, endotoxin presence was greater in the diseased group before banding (P < or = 0.0002), and at 20 (P < or = 0.0008), 40 (P < or = 0.002), 60 (P < or = 0.006), and 120 (P < or = 0.01) minutes after banding.
Endotoxemia is more frequently present in catheterized dogs with dimethylnitrosamine-induced hepatic disease and multiple PSS, compared with clinically normal dogs. Additionally, portal pressure changes induced by vena caval banding did not affect endotoxemia.
Endotoxemia may exist in dogs with hepatic disease and multiple PSS, and should be kept in mind when formulating treatment (particularly antimicrobial selection) for dogs with suspected endotoxemia.
在犬多门体分流（PSS）模型中记录门静脉和体循环血液中内毒素的存在情况，并比较腔静脉结扎前后临床正常犬的内毒素值。
6只对照犬和10只由二甲基亚硝胺诱导产生多PSS并接受腔静脉结扎的犬。
对患病组的10只犬口服二甲基亚硝胺（2mg/kg体重，每周两次），直至出现多PSS。然后对所有16只犬（两组）进行手术，并在患病犬中确认分流情况。从门静脉、肝静脉和尾腔静脉采集血液用于基线内毒素测定以及需氧和厌氧血液培养。从门静脉导管进行基线压力测量；然后进行腔静脉结扎。在结扎后20、40、60、120、240和360分钟从所有血管采集用于内毒素测定的血液；在采集样本的同时进行门静脉压力测量。在结扎后120、240和360分钟从门静脉和肝静脉导管采集用于培养的血液。
患病组犬门静脉（P≤0.0002）、肝静脉（P≤0.0001）和尾腔静脉（P≤0.0004）内毒素的总体存在量显著高于对照犬。在时间方面，患病组在结扎前（P≤0.0002）以及结扎后20分钟（P≤0.0008）、40分钟（P≤0.002）、60分钟（P≤0.006）和120分钟（P≤0.01）时内毒素的存在量更高。
与临床正常犬相比，患有二甲基亚硝胺诱导的肝脏疾病和多PSS的插管犬更常出现内毒素血症。此外，腔静脉结扎引起的门静脉压力变化不影响内毒素血症。
患有肝脏疾病和多PSS的犬可能存在内毒素血症，在为疑似内毒素血症的犬制定治疗方案（特别是抗菌药物选择）时应予以考虑。
