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1、1,低血糖症,蔡晓频,2010-5-21,2,Whipple三联症,1938年提出 低的血糖数值 低血糖症状 自主神经兴奋（饥饿，心悸，出汗，恶心，震颤，焦虑） 中枢神经系统功能受损（乏力，抽搐，昏迷） 纠正血糖后症状缓解,2010-5-21,3,最常见原因,糖尿病相关 DCCT：1型糖尿病患者1030%经历 1次严重低血糖 UKPDS：胰岛素治疗的2型糖尿病患者1.2% 发生严重低血糖 1型与2型相似,2010-5-21,4,糖稳态的调节,胰岛素 胰高糖素 肾上腺素 生长激素 皮质醇 调节受损（药物，糖尿病，肝衰竭，肾衰竭）,2010-5-21,5,低血糖分类,空腹低血糖 反应性低血糖（餐后
2、低血糖）,2010-5-21,6,空腹低血糖病因,药源性 高剂量水杨酸，阻滞剂，磺胺药，奎宁，奎尼丁，喹诺酮类 器官衰竭（肝，肾，内分泌病） 肿瘤（非胰岛细胞肿瘤，胰岛细胞瘤，胰岛细胞增生） 自身免疫（IAA,IRA）,2010-5-21,7,反应性低血糖,倾倒综合症（核素胃排空试验） 糖尿病前期 胰岛细胞增生,2010-5-21,8,胰岛细胞瘤,Approximately 90% of insulinomas are single and benign; 10 to 15%, usually multiple adenomas, are associated with multiple en
3、docrine neoplasia,2010-5-21,9,胰岛细胞瘤,When the clinical suspicion is present, diagnosis depends on the demonstration of hyperinsulinemic hypoglycemia.,2010-5-21,10,胰岛细胞瘤定性诊断,If spontaneous hypoglycemia is not encountered, supervised prolonged fasting may be required . In the presence of an insulinoma,
4、 the semiautonomous basal insulin secretion inhibits hepatic glucose efflux, leading to fasting hypoglycemia. The finding of hypoglycemia (plasma glucose 6 U/mL), C-peptide (0.2 nmol/L), and proinsulin (20 pmol/L) is usually considered diagnostic,2010-5-21,11,胰岛细胞瘤定性诊断,Prolonged fasting with demonst
5、ration of hypoglycemia although recognized as the gold standard of diagnosis, is uncomfortable to the patient and is potentially hazardous. Gin et al. reported on the use of euglycemic hyperinsulinemic clamp to diagnos insulinoma. Patients with insulinoma showed lack of C-peptide suppression during
6、three successive 90-minute exogenous insulin infusions of up to 8 mU/kg/min, in contrast to control subjects, whose levels progressively fell to 0.30.1 ng/mL by the third phase. Using C-peptide level at phase 3 of 0.3 ng/mL as the cut-off point, patients with insulinoma were distinguished from contr
7、ol subjects with a sensitivity of 100%. The test lasted only 270 minutes and all patients remained euglycemic throughout the study.,2010-5-21,12,胰岛细胞瘤定位诊断,Preoperative localization of tumors using conventional imaging modalities such as ultrasonography and computed tomography have been disappointing
8、, with identification of only 20 to 50% of tumors,2010-5-21,13,超声,Transabdominal ultrasonography has a reported sensitivity between 7 to 79% ，often limited by the presence of bowel gas obscuring a full view of the pancreas.,2010-5-21,14,增强CT,As most of the tumors are hypervascular, conventional dyna
9、mic contrast computed tomography detects the tumor at the early arterial phase after contrast injection, but the sensitivity reaches only 78%, with even lower detection rates for lesions under 2 cm.,2010-5-21,15,双相螺旋CT,The introduction of dual-phase spiral computed tomography allows for more rapid a
10、cquisition of early arterial and arteriovenous perfusion phase, as well as multidimensional reformatted image reconstruction. The sensitivity achieved has been reported to reach 100% with detection of tumor down to 0.8 cm,2010-5-21,16,MRI,Magnetic resonance imaging with injection of superparamagneti
11、c iron oxide particles has been shown to distinguish focal nodular hyperplasia from metastatic disease The sensitivity of magnetic resonance imaging for the detection of primary pancreatic tumor diminishes, however, with decreasing tumor size from up to 100% in large tumors to 30% when lesions are u
12、nder 2 cm,2010-5-21,17,奥曲肽扫描,Somatostatin-receptor scintigraphy has been used in the detection of neuroendocrine tumors . Unfortunately, half of insulinomas do not express somatostatin receptors, and the sensitivity at best reaches 60%. However, when a lesion is detected, the positive predictive val
13、ue can reach 100%,2010-5-21,18,血管造影,Angiography, Reported sensitivities are up to 72.2% at best with the use of digital subtraction angiography but reach 100% when combined with intra-arterial calcium stimulation test The latter depends on the functional status of the tumor and has replaced the more
14、 hazardous procedure of percutaneous transhepatic venous sampling.,2010-5-21,19,钙刺激试验,This was modified by Doppman et al. with the use of calcium for detection of insulinoma. In vitro studies show that a high extracellular calcium concentration invokes a rapid elevation of intracellular calcium conc
15、entration and almost instantaneous increase in insulin release in insulinoma cells, regardless of the glucose levela finding not seen in normal b cell lines During arterial-stimulated venous sampling, calcium gluconate is injected to each selectively cannulated artery, namely the gastroduodenal, sup
16、erior mesenteric, splenic, and hepatic arteries. Venous samples for insulin are obtained from the right hepatic vein at baseline and serially up to 3 minutes after calcium injection. A positive test result, defined as a rise of twofold or more in immunoreactive insulin level from baseline , is indicative of a functional insulinoma in the vascular territory of the selected artery,2010-5-21,20,2010-5-21,21,内镜超声,Endoscopic ultrasonography is one of the major breakthroughs in the last decade an
