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Query: UMLS:C0036690 (sepsis)
 59,461 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To determine if concentration of plasma arginine vasopressin (AVP) is inappropriate for the plasma Na+ concentration in hyponatremic burned patients, we obtained 32 plasma samples from 20 patients with total burn size (TBS) 15 to 80% of body surface on or after postburn day (PBD) 4 in the morning following all-night recumbency. In the 25 samples (17 patients) with hyponatremia, AVP was elevated, 1.6 to 14.3 (normal less than 0.5) pg/ml. Most patients with normal serum Na+ had normal AVP values. Out of the total, nine patients (12 samples) without renal failure or sepsis, selected also for hyponatremia and urinary Na+ greater than or equal to 20 mEq/L, were considered separately. BUN of 11.7 +/- 1.8 mg/dl and plasma glucose of 130 +/- 5.6 mg/dl, Na+ of 130 +/- 1.1 mEq/L, calculated osmolality of 272 +/- 1.6 mosm/kg, and cortisol of 20.4 +/- 1.6 micrograms/dl were associated with a 24-hour fluid intake of 4.3 +/- 0.26 L and urinary output of 2.7 +/- 0.33 L, Na+ of 80 +/- 14 mEq/L, and osmolality of 520 +/- 73 mosm/kg (mean +/- SE). In all of the plasma samples, AVP was markedly elevated (6.9 +/- 1.1 pg/ml). In another study, four hyponatremic burned patients were given a standard water load. Excretion of the water was delayed, and further dilution of the initially hypotonic plasma resulted in a fall of urinary osmolality and plasma AVP. Cutaneous thermal injury can cause resetting of the mechanism linking plasma tonicity and AVP secretion resulting in dilutional hyponatremia. This syndrome occurs in the absence of gross physiologic perturbations such as volume depletion or adrenal insufficiency.
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PMID:Inappropriate vasopressin secretion (SIADH) in burned patients. 683 44

The aetiology of hyponatremia in tetraplegic patients is multifactorial and includes not only general factors such as the use of diuretics and the intravenous infusion of hypotonic fluids, but also certain mechanisms which operate in the spinal cord injured: decreased renal water excretion due to both intrarenal and arginine vasopressin dependent mechanisms (resetting of the osmostat), coupled with habitually increased fluid intake, and the ingestion of a low salt diet. Between 1984 and 1993 we treated 28 episodes of hyponatremia in 19 patients (males: 10; females: 9). Fourteen were tetraplegic and five paraplegic (thoracic lesion in four and lumbar lesion in one). Six patients were asymptomatic during seven episodes of hyponatremia which were detected during routine blood tests. Seven patients were suffering from an acute chest infection, three had an acute urinary tract infection, one had an infected ischial pressure sore and a 69 year old paraplegic patient had bronchopneumonia as well as sepsis from a gangrenous pressure sore in the supraanal region. The time interval between the onset of paralysis and occurrence of the first episode of hypnoatremia was less than a month in only four of the patients. The lowest plasma sodium level observed was less than 100 mmol/l in two, between 100 and 110 mmol/l in four, between 111 and 120 mmol/l in eight patients, and between 121 and 128 mmol/l in 14 cases. Six patients also had hypokalemia (K+ < 3 mmol/l). Only one patient had and elevated plasma creatinine (201 umol/l). Treatment of sepsis and fluid restriction were the mainstay of treatment with only two patients receiving hypertonic saline. All patients with underlying sepsis were treated with antibiotics, usually administered intravenously. The outcome was good in 26 of the 28 episodes. Two patients died: a 68 year old tetraplegic patient with consolidation of the left lung, cystadenocarcinoma of both ovaries and squamous cell carcinoma of the forehead who presented with generalised oedema, with a plasma sodium level of 118 mmol/l, and potassium of 2.4 mmol/l and who was treated with 2 N saline + potassium + frusemide; she died 1 day later. The only other death was that of a 78 year old female tetraplegic patient who 2 days after sustaining cervical trauma developed hyponatremia because of intravenous infusion of hypotonic fluids given at another hospital, presumably to correct hypotension. She recovered from hyponatremia with fluid restriction, but 3 days later she succumbed to bronchopneumonia and respiratory insufficiency. No patient developed central pontine myelinolysis.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:A retrospective study of hyponatremia in tetraplegic/paraplegic patients with a review of the literature. 799 39

Transfusion risks include the possibility of ABO/Rh incompatibility, sepsis, febrile reactions, immunosuppression, and viral transmission; incidences and consequences of these complications are reviewed. Predonation of autologous blood generally reduces the need for homologous blood by about 30% to 40%, but relatively few coronary artery bypass surgery (CABG) patients predonate blood. Drug products to decrease blood use include 1-deamino-8-D-arginine vasopressin (DDAVP), tranexamic acid, epsilon-aminocaproic acid, and aprotinin. A recent study suggests that a subgroup of patients with abnormal platelet function may benefit from a platelet therapy such as DDAVP. The prophylactic use of tranexamic acid reduces cardiac surgery postoperative blood loss, as measured by chest-tube output, by about 30%; unfortunately, data demonstrating a reduction in transfusion requirements are not available. Aprotinin use is associated with major reductions in blood transfusion requirements. Aprotinin provides platelet protection during cardiopulmonary bypass. Duration of stay in the intensive care unit was not increased by use of aprotinin, thus alleviating some concerns that aprotinin might promote coronary thrombosis. A recent report cites early graft closure as a major concern with aprotinin therapy, but data from other studies show no significant differences in rates of graft closure between patients receiving and those not receiving aprotinin. Routine use of a thromboelastogram with all cardiopulmonary bypass surgery at the University of Washington Hospital has reduced use of blood products by 30%.
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PMID:Cardiac anesthesia risk management. Hemorrhage, coagulation, and transfusion: a risk-benefit analysis. 816 99

Immune neuroendocrine interactions are vital for the individual's survival in certain physiopathological conditions, such as sepsis and tissular injury. It is known that several animal venoms, such as those from different snakes, are potent neurotoxic compounds and that their main component is a specific phospholipase A type 2 (PLA2). It has been described recently that the venom from Crotalus durissus terrificus [snake venom (SV), in the present study] possesses some cytotoxic effect in different in vitro and in vivo animal models. In the present study, we investigated whether SV and its main component, PLA2 (obtained from the same source), are able to stimulate both immune and neuroendocrine functions in mice, thus characterizing this type of neurotoxic shock. For this purpose, several in vivo and in vitro designs were used to further determine the sites of action of SV-PLA2 on the hypothalamo-pituitary-adrenal (HPA) axis function and on the release of the pathognomonic cytokine, tumor necrosis factor alpha (TNF alpha), of different types of inflammatory stress. Our results indicate that SV (25 microg/animal) and PLA2 (5 microg/animal), from the same origin, stimulate the HPA and immune axes when administered (i.p.) to adult mice; both preparations were able to enhance plasma glucose, ACTH, corticosterone (B), and TNF alpha plasma levels in a time-related fashion. SV was found to activate CRH- and arginine vasopressin-ergic functions in vivo and, in vitro, SV and PLA2 induced a concentration-related (0.05-10 microg/ml) effect on the release of both neuropeptides. SV also was effective in changing anterior pituitary ACTH and adrenal B contents, also in a time-dependent fashion. Direct effects of SV and PLA2 on anterior pituitary ACTH secretion also were found to function in a concentration-related fashion (0.001-1 microg/ml), and the direct corticotropin-releasing activity of PLA2 was additive to those of CRH and arginine vasopressin; the corticotropin-releasing activity of both SV and PLA2 were partially reversed by the specific PLA2 inhibitor, manoalide. On the other hand, neither preparation was able to directly modify spontaneous and ACTH-stimulated adrenal B output. The stimulatory effect of SV and PLA2 on in vivo TNF alpha release was confirmed by in vitro experiments on peripheral mononuclear cells; in fact, both PLA2 (0.001-1 microg/ml) and SV (0.1-10 microg/ml), as well as concavalin A (1-100 microg/ml), were able to stimulate TNF alpha output in the incubation medium. Our results clearly indicate that PLA2-dependent mechanisms are responsible for several symptoms of inflammatory stress induced during neurotoxemia. In fact, we found that this particular PLA2-related SV is able to stimulate both HPA axis and immune functions during the acute phase response of the inflammatory processes.
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PMID:A phospholipase A2-related snake venom (from Crotalus durissus terrificus) stimulates neuroendocrine and immune functions: determination of different sites of action. 944 33

Before de novo synthesized von Willebrand factor (vWF) leaves the endothelial cell, it undergoes endoproteolytic cleavage of its propeptide (vW antigen II). The processed vWF and propeptide are either released constitutively or, following activation of the endothelium, released through the regulated pathway. In a recent study (Borchiellini et al, Blood 88:2951, 1996), we showed that the half-life of mature vWF and of its propeptide differ fourfold to fivefold. We postulated that the molar ratio of the propeptide to mature vWF could serve as a tool to assess the extent of endothelial cell activation under physiologic and clinical conditions. To test this hypothesis, we measured mature vWF and propeptide in patients with documented acute and chronic vascular disease, including patients with thrombotic thrombocytopenic purpura (TTP), acute septicemia, and diabetes mellitus. These data were compared with experimental conditions in healthy subjects in which perturbation of the endothelium was simulated by physical exercise or by administration of 1-deamino-8-D-arginine vasopressin (DDAVP) or endotoxin. In all individuals of the latter study group, both vWF and propeptide levels were elevated during the acute phase of the experimentally induced vascular perturbation; at later time points after stimulation, only vWF levels remained elevated. In patients with sepsis and TTP, both vWF and propeptide were elevated several-fold. Thus, this pattern can readily be explained in terms of acute perturbation of the endothelium. In contrast, in patients with diabetes mellitus propeptide levels were only slightly elevated, whereas vWF levels were elevated twofold to threefold. This pattern is a typical feature of chronic, low-grade activation of the endothelium. These observations support our hypothesis that measurement of both propeptide and vWF levels allows to discriminate between chronic and acute phases of endothelial cell activation in vivo. Measurement of only vWF is less indicative in this respect.
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PMID:von Willebrand factor propeptide in vascular disorders: A tool to distinguish between acute and chronic endothelial cell perturbation. 1038 11

It is well recognized that the reciprocal interaction established between the immune and neuroendocrine systems is crucial for the homeostatic adaptation of individuals during septicemia. In the present study, using an in vivo rat model, we investigated the degree of participation of central and peripheral epinergic systems in the modulation of the hypothalamic-pituitary-adrenal and immune axes' functions during endotoxemia. For this purpose, acute endotoxemia was induced in adult male rats pretreated intraperitoneally with either different inhibitors of phenylethanolamine-N-methyltransferase (PNMT) [which are active either peripherally (SKF 29661) or both peripherally and centrally (SKF 64139), thus lowering epinephrine (EPI) synthesis] or vehicle only (CTRL). Twelve hours after pretreatment, animals were intraperitoneally injected with vehicle alone (basal) or vehicle containing bacterial lipopolysaccharide (LPS) and sacrificed 2 h later. A significant (p < 0.05 vs. the respective basal value) hypoglycemia was found in all groups studied. No pretreatment modified basal plasma adrenocorticotropic hormone (ACTH), glucocorticoid and cytokine concentrations. Endotoxin-stimulated ACTH secretion was severalfold (p < 0.05) higher than the respective basal value in CTRL and in SKFs-pretreated rats; however, the plasma ACTH levels after LPS were significantly (p < 0.05 vs. CTRL and SKF-29661 values) reduced in SKF-64139-pretreated rats. All groups studied showed an appropriate adrenal response to endotoxin challenge. Although no differences were found in basal anterior pituitary (AP) ACTH content among groups, LPS treatment significantly (p < 0.05 versus the respective basal value) decreased AP ACTH in CTRL and SKF 29661 groups. No pretreatment modified the basal medial basal hypothalamus (MBH) corticotropin-releasing hormone (CRH) content. Conversely, SKF 64139 pretreatment significantly (p < 0.05 vs. CTRL and SKF 29661 values) reduced basal median eminence (ME) CRH content, and LPS administration significantly (p < 0.05) decreased ME CRH in CTRL and SKF-29661-pretreated rats. SKF 64139 pretreatment significantly (p < 0.05) enhanced basal MBH and ME arginine vasopressin (AVP) contents. LPS administration significantly (p < 0.05) decreased MBH AVP in CTRL and SKF-29661-pretreated rats and diminished (p < 0.05 vs. basal values) ME AVP in all groups. The plasma tumor necrosis factor alpha (TNFalpha) concentrations were enhanced severalfold (p < 0.05 vs. basal values) after LPS treatment in CTRL rats, but not in SKFs-treated animals. In order to explore the reduced cytokine release after LPS in PNMT-inhibited rats, additional ex vivo experiments were performed by using peripheral mononuclear cells (PMNC) from both CTRL and SKF-29661-pretreated rats. The results of these experiments confirmed an immune dysfunction after inhibition of peripheral EPI synthesis; in fact, basal and concanavalin-A-stimulated TNFalpha secretions were significantly (p < 0.05) lower in SKF-29661-treated than in CTRL PMNC, while, interestingly, addition of EPI (10(-7) M) to the medium fully restored these effects. These data demonstrate that: (1) the mechanism whereby LPS-induced hypoglycemia was independent of epinergic activity; (2) selective central inhibition of epinergic function reduced endotoxin-stimulated ACTH secretion, an effect that could mainly be due to a decrease in CRH-ergic activity; (3) the central epinergic system positively and negatively modulates CRH- and AVPergic functions, respectively, and (4) inhibition of peripheral PNMT activity reduced immune system function in vivo and ex vivo. It is further suggested that low peripheral levels of EPI could be beneficial for the body's defense mechanisms during endotoxic shock.
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PMID:Modulatory role of the epinergic system in the neuroendocrine-immune system function. 1096 35

In the current issue of Critical Care, Friesenecker and colleagues present a well-designed comparative study on the microvascular effects of arginine vasopressin (AVP) and norepinephrine (NE) in a physiological, unanesthetized hamster model. The authors clearly demonstrate that AVP, but not NE, has marked vasoconstrictive effects on large arterioles, whereas the impact on small arterioles is comparable for both vasopressors. However, it remains unclear if these results, per se, reflect a stronger vasopressive potential of AVP versus NE, as macrohemodynamic variables were not different between study groups. Since the authors did not investigate the effects of AVP and NE in vasodilatory shock states, the microcirculatory response in sepsis or systemic inflammatory response syndrome remains inconclusive. The same authors previously reported that AVP infusion in patients suffering from vasodilatory shock carries the risk for ischemic skin lesions. This in turn raises the question whether the quality of vasopressors should be judged by their potency.
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PMID:Arginine vasopressin versus norepinephrine: will the stronger one win the race? 1669 66

Vasodilatory shock is the most common form of shock in the critically ill patient. As a consequence of overwhelming and prolonged mediator production, vasodilatory shock can be the common final pathway of primary non-vasodilatory shock (e.g. cardiogenic or hypovolemic shock). A supplementary infusion of arginine vasopressin (AVP) showed beneficial effects on hemodynamics and potentially on the outcome in patients with vasodilatory shock due to sepsis or after major surgery. In this case series, successful administration of AVP in three surgical patients with primary cardiogenic shock forms is reported. The hemodynamic effects of AVP were comparable to those AVP-induced alterations described in septic shock and seem to be predominantly mediated by potent vasoconstriction and the facilitated reduction of higher, potentially toxic catecholamine doses. Thus, an AVP-induced decrease in heart rate and pulmonary arterial pressures may be particularly beneficial in patients with impaired cardiac function.
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PMID:[Vasopressin as a rescue vasopressor agent. Treatment of selected cardiogenic shock states]. 1759 65

Infusing arginine vasopressin (AVP) in advanced vasodilatory shock is usually accompanied by a decrease in cardiac index and systemic oxygen transport. Whether or not such a vasoconstriction impedes regional blood flow and thus visceral organ function, even when low AVP is used, is still a matter of debate. Krejci and colleagues now report, in this issue of Critical Care, that infusing 'low-dose' AVP during early, short-term, normotensive and normodynamic fecal peritonitis-induced porcine septicemia markedly reduced both renal and portal blood flow, and consequently total hepatic blood flow, whereas hepatic arterial flow was not affected. This macrocirculatory response was concomitant with reduced kidney microcirculatory perfusion, whereas liver micro-circulation remained unchanged. From these findings the authors conclude that the use of AVP to treat hypotension should be cautioned against in patients with septic shock. Undoubtedly, given its powerful vasoconstrictor properties, which are not accompanied by positive inotropic qualities (in contrast with most of the equally potent standard care 'competitors', namely catecholamines), the safety of AVP is still a matter of concern. Nevertheless, the findings reported by Krejci and colleagues need to be discussed in the context of the model design, the timing and dosing of AVP as well as the complex interaction between visceral organ perfusion and function.
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PMID:Vasopressin in vasodilatory shock: hemodynamic stabilization at the cost of the liver and the kidney? 1807 8

Recent studies revealed that vasopressinergic neurons have a high content of cys-leukotriene C(4) (LTC(4)) synthase, a critical enzyme in cys-leukotriene synthesis that may play a role in regulating vasopressin secretion. This study investigates the role of this enzyme in arginine vasopressin (AVP) release during experimentally induced sepsis. Male Wistar rats received an i.c.v. injection of 3-[1-(p-chlorobenzyl)-5-(isopropyl)-3-tert-butylthioindol-2-yl]-2, 2-dimethylpropanoic acid (MK-886) (1.0 microg/kg), a leukotrienes (LTs) synthesis inhibitor, or vehicle, 1 h before cecal ligation and puncture (CLP) or sham operation. In one group of animals the survival rate was monitored for 3 days. In another group, the animals were decapitated at 0, 4, 6, 18 and 24 h after CLP or sham operation, and blood was collected for hematocrit, serum sodium and nitrate, plasma osmolality, protein and AVP determination. A third group was used for blood pressure measurements. The neurohypophysis was removed for quantification of AVP content, and the hypothalamus was dissected for LTC(4) synthase analysis by Western blot. Mortality after CLP was reduced by the central administration of MK-886. The increase in plasma AVP levels and hypothalamus LTC(4) synthase content in the initial phase of sepsis was blocked, whereas the decrease in neurohypophyseal AVP content was partially reversed. Also the blood pressure drop was abolished in this phase. The increase of serum nitric oxide and hematocrit was reduced, and the decrease in plasma protein and osmolality was not affected by the LTs blocker. In the final phase of sepsis, the plasma AVP level and the hypothalamic LTC(4) synthase content were at basal levels. The central administration of MK-886 increased the hypothalamic LTC(4) synthase content but did not alter the plasma and neurohypophysis AVP levels observed, or the blood pressure during this phase. These results suggest that the central LTs are involved in the vasopressin release observed during sepsis.
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PMID:Blocking central leukotrienes synthesis affects vasopressin release during sepsis. 1928 13


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