Agarwal N, Pitchumoni C S, Sivaprasad A V
Department of Surgery, Our Lady of Mercy Medical Center, Bronx, New York.
Am J Gastroenterol. 1990 Apr;85(4):356-66.
The relative merits of various serum pancreatic enzymes, ultrasonography (US), and computerized tomography (CT) have been evaluated. In practice, the diagnosis of acute pancreatitis (AP) remains hinged on the clinical picture and elevated serum amylase. The advantages of total serum amylase are its technical simplicity, ready availability, and sensitivity. Within 24 h of onset of symptoms, elevation of amylase is as sensitive as that of lipase, pancreatic isoamylase, immunoreactive trypsin, or elastase. However, after the first hospital day, it is the least sensitive of the enzymatic tests. Its greatest disadvantage is its overall low specificity. Lipase assays are now fast, reliable, practical, more specific, almost as sensitive, and not more expensive than amylase assays. The current feeling is that lipase assays should be used more often or even should replace amylase assays. However, comparative studies using objective criteria for AP are required to evaluate the utility of lipase estimations over that of amylase. Other enzymes such as P-isoamylase, immunoreactive trypsin, chymotrypsin, or elastase are more cumbersome, expensive, and not better than lipase. They should be reserved for cases of doubtful diagnoses. The levels of these pancreatic enzymes neither correlate with the severity of the disease nor can they accurately predict the subsequent clinical course of the patients. The main role of ultrasonography remains in the evaluation of the biliary tract in AP. The contrast-enhanced computed tomography (CECT) is useful for estimating the presence and extent of pancreatic necrosis. Thereby, it enables prompt recognition of patients at high risk for systemic and local complications. Routine use of CECT may aid in the identification of pancreatitis when enzyme elevations are modest, but the utility of the procedure in all clinically mild cases is questionable. Patients who are seriously ill or who present a diagnostic problem should have a CECT. A normal CT under such circumstances excludes clinically severe AP. Serial CT should be done in patients demonstrating phlegmonous extrapancreatic spread.
已对各种血清胰酶、超声检查（US）和计算机断层扫描（CT）的相对优点进行了评估。在实际操作中，急性胰腺炎（AP）的诊断仍取决于临床表现和血清淀粉酶升高。总血清淀粉酶的优点是技术操作简单、易于获得且具有敏感性。在症状出现后的24小时内，淀粉酶升高与脂肪酶、胰淀粉酶同工酶、免疫反应性胰蛋白酶或弹性蛋白酶升高的敏感性相同。然而，在入院后的第一天之后，它是酶学检测中最不敏感的。其最大的缺点是总体特异性较低。脂肪酶检测现在快速、可靠、实用、更具特异性，几乎与淀粉酶检测一样敏感，且成本并不更高。目前的看法是，脂肪酶检测应更频繁地使用，甚至应取代淀粉酶检测。然而，需要使用AP的客观标准进行比较研究，以评估脂肪酶测定相对于淀粉酶测定的效用。其他酶，如P-淀粉酶同工酶、免疫反应性胰蛋白酶、糜蛋白酶或弹性蛋白酶，操作更繁琐、成本更高，且并不比脂肪酶更好。它们应保留用于诊断存疑的病例。这些胰酶的水平既与疾病的严重程度无关，也不能准确预测患者随后的临床病程。超声检查的主要作用仍然是评估AP患者的胆道情况。增强计算机断层扫描（CECT）有助于评估胰腺坏死的存在和范围。因此，它能够迅速识别有发生全身和局部并发症高风险的患者。当酶升高不明显时，常规使用CECT可能有助于胰腺炎的诊断，但该检查在所有临床症状较轻的病例中的效用值得怀疑。病情严重或存在诊断问题的患者应进行CECT检查。在这种情况下，CT正常可排除临床严重的AP。对于出现胰腺外蜂窝织炎扩散的患者，应进行系列CT检查。
