The mediators responsible for maintenance of the hyperdynamic state and the low systemic vascular resistance (SVR) observed in sepsis have not been elucidated. Nitric oxide (.N = O) is a mediator with numerous functions, including regulation of vascular tone and a role in macrophage-mediated cytostasis and microbiostasis. Thirty-nine critically ill trauma and septic patients were studied to determine the relationship between .N = O production and the hyperdynamic state. high plasma levels of NO2-/NO3- (the stable end products of .N = O) were observed in septic patients (p less than 0.02). Low SVR and high endotoxin levels were associated with high NO2-/NO3- values (p = 0.029, p = 0.002). Changes in .N = O levels may mediate the vasodilation seen in sepsis. Low NO2-/NO3- levels were observed in trauma patients (p less than 0.001) and remained low even in the presence of sepsis (p = 0.001).

A great deal has been learned about the pathophysiologic condition of hemorrhagic shock. The response of the hormonal and inflammatory mediator systems in patients in hemorrhagic shock appears to represent a distinct set of responses different from those of other forms of shock. The classic neuroendocrine response to hemorrhage attempts to maintain perfusion to the heart and brain, often at the expense of other organ systems. This intense vasoconstriction occurs via central mechanisms. The response of the peripheral microcirculation is driven by local tissue hypoperfusion that results in vasodilation in the ischemic tissue bed. Activation of the systemic inflammatory response by hemorrhage and tissue injury is an important component of the pathophysiologic condition of hemorrhagic shock. Activators of this systemic inflammatory response include ischemia/reperfusion injury and neutrophil activation. Capillary "no-flow" with prolonged ischemia and "no-reflow" with reperfusion may initiate neutrophil activation in patients in hemorrhagic shock. The mechanisms that lead to decompensated and irreversible hemorrhagic shock include (1) "arteriolar hyposensitivity" as manifested by progressive arteriolar vasodilation and decreased responsiveness of the microcirculation to alpha-agonists, and (2) cellular injury and activation of both proinflammatory and counterinflammatory mechanisms. These changes represent a failure of the microcirculation. Redistribution of cardiac output and persistent gut ischemia after adequate resuscitation may also contribute to the development of irreversible hemorrhagic shock. Treatment of hemorrhagic shock includes rapid operative resuscitation to limit activation of the mediator systems and abort the microcirculatory changes that result from hemorrhagic shock. Volume resuscitation and control of hemorrhage, should occur simultaneously. The end point in volume resuscitation of hemorrhagic shock must be maintenance of organ system and cellular function. Whether we use adequate urine output, correction of lactic acidemia, optimization of oxygen delivery, or oxygen consumption as our specific goal, the general objective is to provide adequate crystalloid solution and packed red blood cells to achieve and maintain normal organ and cellular perfusion and function.

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In 1947, a patient with metastatic islet cell tumor was treated for intractable ulcer disease at the University of Chicago Medical Center. Eight years later, in retrospect, it was recognized that he and another patient had the Zollinger-Ellison syndrome (ZE). From 1947 until the present, 30 patients with the ZE syndrome have been treated at this institution. Twenty-one (70%) were male and 9 (30%) were female. Their ages ranged from 24 to 76 years. Most (79%) had abdominal pain, however, melena (42%), hematemesis (33%), and severe diarrhea (35%) were prominent as well. Symptoms were present for a mean of 5.8 years before diagnosis. Over their entire clinical course, duodenal ulcers occurred in 96% of patients, gastric ulcers in 24%, jejunal ulcers in 29%, esophageal ulcers in 6%, and stomal ulcerations in 58%. Eleven (38%) of all gastrinomas were proved to occur in the duodenum; 10 (34%) were pancreatic in origin, including 3 with the MEN I syndrome; 3 (10%) were extrapancreatic and extraduodenal in origin, and no tumor was found in 5 (17%). Each of the 3 patients with MEN I developed a proven pancreatic islet cell carcinoma with metastases as well as hyperparathyroidism and a pituitary lesion. Of 27 patients who were explored for gastrinoma, tumor was found in 20 (74%). Excluding patients with MEN who had multiple lesions throughout the pancreas, all tumors were found in the "gastrinoma triangle." Total gastrectomy was performed in 10 (37%) of 27 of all patients who were explored, in 5 (71%) of 7 when no tumor was found, and in only 5 (25%) of 20 when tumor was present. Operative mortality was 15% (4 of 27) but no death has occurred since 1974. Long-term survival has followed both tumor resection or total gastrectomy in selected individuals (including 1 patient with known multiple liver metastases who is alive 18 years after liver biopsy and total gastrectomy); however, since malignant gastrinomas were present in 46% of all patients (or 57% in whom tumor was found) and since local metastases can sometimes be removed, we favor an aggressive approach to localization and resection when liver metastases or other distant metastases are not found. Duodenal gastrinomas are particularly favorable for resection for cure. They were malignant in only 36% and their metastases were nodal in each of 4 cases. The major problem is finding them since they are often small and "occult."(ABSTRACT TRUNCATED AT 400 WORDS)

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