Cost effectiveness of selective decontamination of the digestive tract in liver transplant patients.

OBJECTIVE: To assess the cost effectiveness of selective decontamination of the digestive tract (SDD) in liver transplant patients. DESIGN: Randomised, placebo-controlled, double-blind trial with an integrated economic evaluation. SETTING: Two university hospitals in The Netherlands. Cost effectiveness was assessed from a societal perspective. PATIENTS AND PARTICIPANTS: 58 patients who underwent liver transplantation and received SDD (n = 29) or placebo (n = 29) pre- and postoperatively. INTERVENTIONS: SDD medication and placebo. MAIN OUTCOME MEASURES: Infection episodes, days of infection, costs of SDD and routine cultures, mean other direct medical costs per patient and additional costs of severe infection. RESULTS: Costs of SDD medicine and routine cultures were on average 3,100 US dollars ($US; 1997 values) per patient who underwent SDD. Both preoperatively and postoperatively, costs other than SDD and cultures did not significantly differ between the SDD and the placebo groups (preoperative, $US2,370 vs $US2,590; postoperative, $US25,455 vs $US24,915). Additional postoperative costs of severe infections were $US250 per day per patient. There were no significant differences in the mean number of infection episodes between groups. CONCLUSIONS: SDD leads to the additional costs of SDD medication and routine cultures, whereas no savings in other costs and no improvement in infection episodes are realised. Consequently, SDD may be considered as a nonefficient approach in patients undergoing liver transplantation. The additional costs of severe infection are considerable.

The capability of isolated hepatocytes and liver slices of donor livers to predict graft function after liver transplantation.

AIMS/BACKGROUND: In liver transplantation, adequate function tests for donor livers and transplanted livers are of utmost importance to provide an objective basis for decision-making. Isolated hepatocyte and/or slice preparations from human donor liver tissue may be suitable to test the quality of the organ to be transplanted. METHODS: Surgical waste material remaining after reduced size or split liver transplantation in children was used to prepare slices and isolated hepatocytes. The viability of these preparations as well as drug transport and metabolism functions were determined and related to graft function in 32 liver recipients. RESULTS: The in vitro tests used in the present study apparently did not select non-viable livers. In vitro preparations of the primary non-function grafts which occurred in the investigated group showed normal viability, metabolic and uptake function. CONCLUSION: These results indicate that either the presently used viability tests are not sensitive enough to detect potential organ failure or that other factors besides the hepatocyte viability at the time of transplantation are of paramount importance to the graft function of the recipient, such as complications during and after transplantation or the viability of the non-parenchymal cells.

Endotoxins and cytokines during liver transplantation: changes in plasma levels and effects on clinical outcome.

Endotoxins, tumor necrosis factor-alpha (TNF-alpha), interleukin-1 (IL-1), and IL-6 are believed to have a key role in liver transplantation. The origin and course of these factors is not completely known. In this prospective study of 40 patients, we sought more understanding of the relations between these factors and their effects on clinical outcome by sampling at different sites. Endotoxemia was only present in 20% of the patients. In 75% of these patients, it was present during the anhepatic phase and quickly resolved after reperfusion. Endotoxemia was not related to a clinical adverse event. TNF-alpha was released from the graft after reperfusion, and initial levels after reperfusion were related to predonation levels in the donor. Only levels of TNF-alpha in the recipient before transplantation were found to be predictive of postoperative complications. We conclude that monitoring endotoxins and these cytokines is of very limited value in predicting outcome.

Gastric mucosal pH is associated with initial graft function but is not a predictor of major morbidity after liver transplantation.

Gastric mucosal pH reflects splanchnic perfusion. Monitoring gastric mucosal pH might be useful in predicting outcome after liver transplantation. Forty patients were included in the study. Gastric mucosal pH and gastric mucosal pH corrected for systemic pH were compared with regard to initial liver function and morbidity. Eighty percent of the patients had at least one episode with a gastric mucosal pH of <7.32, and 84% of these had a concomitant arterial pH of <7.32. No differences in morbidity were found between patients with a gastric mucosal pH of <7.32 and those with a gastric mucosal pH of >7.32. If gastric mucosal pH was corrected for arterial pH, only 49% of the patients had an episode during transplantation with a corrected gastric mucosal pH of <7.32. Comparing these patients with the group that did not have such an episode, we found that flow in the venovenous bypass system was significantly lower (2.9 v 3.4 L/min; P < .02) in the first group. Also alanine aminotransferase and aspartate aminotransferase levels were higher, antithrombin III levels and lidocaine clearance rates were lower, and prothrombin times were longer in the group with corrected gastric mucosal pH of <7.32. No differences with regard to major morbidity and mortality were noted. Gastric mucosal pH during liver transplantation should be corrected for arterial pH. Patients with a corrected gastric mucosal pH of <7.32 are more likely to develop initial liver function tests disturbances, but morbidity is not different from patients with gastric mucosal pH of >7.32.

Poor initial graft function after orthotopic liver transplantation: can it be predicted and does it affect outcome? An analysis of 125 adult primary transplantations.

Donor liver shortage is a persistent problem in liver transplantation. A more liberal donor acceptance policy may be a possible solution. However, this might put recipients at risk for initial poor function or even non-function of the graft. Therefore risk factors for initial graft dysfunction should be identified, preferably by using an uniform definition of primary graft dysfunction or non-function. We retrospectively analysed 125 adult liver transplantations in order to identify risk factors for initial poor function and primary non-function. Donor, recipient pretransplant and surgical parameters were evaluated. Since there is no consensus on the criteria of dysfunction we used two definitions known from literature. No risk factors for postoperative dysfunction could be identified for either of the two definition sets. Furthermore, the definition set that included ALAT, prothrombin time and bile production in the first 72 h to identify poor graft function showed no relation with graft or recipient outcome. The other set, using ASAT and prothrombin time, determined from day 2 to day 7, showed that patients with a primary dysfunction had significantly higher morbidity and mortality compared to patients with a well functioning graft. We conclude that initial poor function after liver transplantation remains unpredictable, irrespective of the way it is defined. Moreover, our analysis shows that initial poor function can also develop in recipients that receive 'non-marginal' grafts without prolonged ischemia times. These results may support a more liberal selection of donor livers.

Value of the in vitro or in vivo monoethylglycinexylidide test for predicting liver graft function.

BACKGROUND: An adequate function test for donor livers is still lacking. The monoethylglycinexylidide (MEGX) test, performed in vivo in the donor to measure the metabolic rate of lidocaine conversion to MEGX, has been proposed as a function test for donor livers to predict postoperative organ function. METHODS: In the present study, we investigated whether the MEGX formation rate measured in needle biopsy specimens in vitro correlates with the rate of MEGX formation in vivo. The in vivo MEGX test was performed in the donors and in the recipients on days 1 and 2. The in vivo and in vitro MEGX tests were compared with posttransplant liver function in the recipients in order to investigate their possible relevance as predictors of graft function. RESULTS: The MEGX formation rate in needle biopsy specimens in vitro showed a significant correlation with the MEGX serum concentration found in the donor. A low rate of MEGX formation in the biopsy specimens tended to predict initial poor function of the grafts. In the donor, the MEGX test did not correlate with general liver function after transplantation. Only the MEGX serum concentration in the recipients on day 2 gave an indication of graft function. CONCLUSIONS: MEGX formation in liver biopsy specimens in vitro properly reflects metabolic function of the particular liver. Therefore, liver biopsies may be a valuable tool to help predict liver function in vivo. However, the MEGX test alone is not sufficient to provide the gold standard to determine liver function in donor and transplantation livers.

Renal function in cancer patients treated with hyperthermic isolated limb perfusion with recombinant tumor necrosis factor-alpha and melphalan.

Hyperthermic isolated limb perfusion (HILP) with recombinant tumor necrosis factor-alpha (r-TNF alpha) and melphalan has been shown to result in a sepsis-like syndrome due to leakage of r-TNF alpha from the perfusion system to the systemic circulation. We have studied renal function parameters in 11 cancer patients, who underwent 12 perfusions. Three patients, perfused with melphalan only, served as controls. All patients treated with r-TNF alpha developed a sepsis syndrome and needed volume replacement and inotropes to remain normotensive; controls had an uneventful postoperative course. Creatinine clearance decreased transiently on the day of perfusion in both groups (mean preperfusion clearance 118 ml/min, mean post-perfusion clearance 68 ml/min, p < 0.02, n = 15). Follow-up measurements of renal plasma flow and glomerular filtration rate in 9 r-TNF alpha-treated patients did not suggest permanent damage. One patient became hypotensive and developed transient multiple organ dysfunction with renal failure needing hemofiltration. In r-TNF alpha-treated patients, but not in controls, a transient increase in clearance of beta2-microglobulin (0.05 vs. 8 ml/min, p < 0.001) and urinary excretion of phosphate (12 vs. 48 mmol/l, p < 0.05) was seen, compatible with proximal tubular dysfunction. These data suggest that HILP with melphalan decreases glomerular function, whether or not r-TNF alpha is added to the perfusion circuit. Extension of the treatment regimen with r-TNF alpha may result in additional proximal tubular dysfunction. If hypotension can be avoided, this deterioration in renal function seems to be transient, with full recovery within weeks.

Augmented procoagulant activity in cancer patients, treated with recombinant interferon-gamma in addition to recombinant tumor necrosis factor-alpha and melphalan.

Several investigators have reported that interferon-gamma (IFN gamma) can alter tumor necrosis factor alpha induced effects in vitro. We assessed in vivo effects of recombinant interferon-gamma (rIFN gamma) on recombinant tumor necrosis factor-alpha (rTNF alpha) induced activation of systemic blood coagulation in a non-randomized study in 20 consecutive cancer patients. Eight patients were treated with rIFN gamma prior to and during hyperthermic isolated limb perfusion with rTNF alpha and melphalan (IFN gamma group). They were compared with twelve patients who did not additionally receive rIFN gamma (non-IFN gamma group). Before start of perfusion, higher levels of TNF alpha, F1+2 and TAT levels were found in the IFN gamma group. Fibrinogen and ATIII levels tended to be lower in this group. High TNF alpha levels, due to leakage during perfusion, were associated with activation of coagulation in all patients, that became obvious after the end of perfusion, when heparin treatment had been antagonized. Activation, measured by increased F1+2 and TAT levels, was significantly stronger in the IFN gamma group. Monocytic TF remained low, possibly due to shedding of TF positive vesicles and/or sequestration of TF positive activated monocytes against the vessel wall. In both groups F1+2 and TAT levels declined 24 h after the perfusion, whereas monocytic TF increased to levels that were higher in the IFN gamma group. In conclusion, our data confirm a strong activation of coagulation induced by rTNF alpha in cancer patients. They suggest that rIFN gamma may lead to a slight activation of coagulation and augments TNF alpha induced procoagulant activity. These effects may be due to rIFN gamma induced sustained monocytic TF activity.

Role of nitric oxide in recombinant tumor necrosis factor-alpha-induced circulatory shock: a study in patients treated for cancer with isolated limb perfusion.

OBJECTIVES: To analyze the mechanism of vasodilation and circulatory shock occurring in patients who are treated with isolated limb perfusion with melphalan and recombinant tumor necrosis factor (TNF)-alpha for locally advanced malignant tumors. To determine the role of nitric oxide, if any, by measuring plasma nitrite and nitrate concentrations. DESIGN: Observational survey. SETTING: A 12-bed surgical intensive care unit in a university referral hospital. PATIENTS: Eight patients treated with hyperthermic isolated limb perfusion. INTERVENTIONS: Ninety minutes of hyperthermic isolated limb perfusion with recombinant TNF-alpha (3 or 4 mg) and melphalan (10 to 13 mg/L limb volume). MEASUREMENTS AND MAIN RESULTS: All patients developed sepsis syndrome due to leakage of recombinant TNF-alpha from the perfusion circuit to the systemic circulation. Despite the presence of very high systemic TNF-alpha concentrations during and immediately after perfusion, and despite definite signs of hyperdynamic circulatory shock (increased heart rate, increased cardiac index, decreased systemic vascular resistance), nitrite and nitrate concentrations, as measured in plasma at several time points, were not increased. CONCLUSIONS: The hypothesis that in humans, TNF-alpha induces vasodilation and shock through activation of inducible nitric-oxide synthase and subsequent formation of excessive quantities of nitric oxide is not substantiated by our results. Normal nitric oxide metabolite concentrations were found in the presence of high TNF-alpha concentrations and shock. Other mechanisms that do not involve the nitric oxide pathway are likely to play a role in the generation of hypotension and septic shock in this setting.

Effects of hyperthermic isolated limb perfusion with recombinant tumor necrosis factor alpha and melphalan on the human fibrinolytic system.

This study was undertaken to determine the effects on systemic fibrinolysis of hyperthermic isolated limb perfusion with recombinant tumor necrosis factor alpha (r-TNF-alpha) and melphalan, with or without pretreatment with recombinant IFN-gamma (r-IFN-gamma). Twenty patients were treated with r-TNF-alpha and melphalan; four patients, treated with melphalan only, served as controls. Of the twenty patients treated with both r-TNF-alpha and melphalan, eight received r-IFN-gamma for two days before the perfusion and as a bolus into the perfusion circuit. A significant leak of r-TNF-alpha from the perfusion circuit to the systemic circulation was observed in all r-TNF-alpha-treated patients (mean maximum TNF-alpha, 87,227 ng/liter versus 31 ng/liter in controls; P < 0.002). In these patients, but not in controls, there was an almost instantaneous rise in systemic tissue plasminogen activator activity (from 0.26 to 5.28 IU/ml in 90 min), causing activation of fibrinolysis. After a delay of 90 min, plasminogen activator inhibitor-1 (PAI-1) antigen rose to high levels in the r-TNF-alpha-treated group (mean maximum PAI-1, 1652 ng/ml versus 211 ng/ml in controls; P < 0.02), associated with a sharp decrease of tissue plasminogen activator activity and a slower decrease of plasminogen-antiplasminogen complexes (from 5.28 to 0.02 IU/ml in 2 h and from 1573 to 347 micrograms/liter in 22 h, respectively). No additional effect of IFN-gamma pretreatment on fibrinolysis could be demonstrated. These results suggest that in isolated limb perfusion with r-TNF-alpha and melphalan an initial activation of systemic fibrinolysis, induced by leakage of r-TNF-alpha from the perfusion circuit, is set off by a subsequent inhibition of the fibrinolytic system by PAI-1. This large increase in PAI-1 could place the patient at risk for deposition of microthrombi in the systemic circulation.

High plasma tumor necrosis factor (TNF)-alpha concentrations and a sepsis-like syndrome in patients undergoing hyperthermic isolated limb perfusion with recombinant TNF-alpha, interferon-gamma, and melphalan.

OBJECTIVES: To describe the postoperative course of patients who underwent hyperthermic isolated limb perfusion with recombinant tumor necrosis factor (TNF)-alpha and melphalan after pretreatment with recombinant interferon-gamma as treatment for recurrent melanoma, primary nonresectable soft-tissue tumors, planocellular carcinoma, or metastatic carcinoma. To measure systemic TNF-alpha concentrations and relate these values with indices of disease severity. SETTING: A 12-bed surgical intensive care unit (ICU) in a university referral hospital. DESIGN: Prospective, descriptive study. PATIENTS: Consecutive patients (n=25) treated with hyperthermic isolated limb perfusion. INTERVENTIONS: Blood samples were taken at regular intervals to determine TNF-alpha concentrations during and after hyperthermic isolated limb perfusion with recombinant TNF-alpha. Hemodynamic variables were obtained with a Swan-Ganz pulmonary artery catheter. MEASUREMENTS AND MAIN RESULTS: All patients developed features of sepsis syndrome and required intensive care treatment. Most patients recovered quickly, with a median ICU stay of 2 days (range 1 to 25). Maximum systemic TNF-alpha concentrations ranged from 2284 to 83,000 ng/L (median 25,409) and returned to baseline values within 8 hrs. Despite these high concentrations of TNF-alpha, no patient died in the ICU, although the patient with the highest TNF-alpha concentration developed multiple organ failure and required continuous venovenous hemofiltration for 16 days. Linear regression analysis showed positive correlations between maximum TNF-alpha concentrations and systemic vascular resistance (p < .01), cardiac index (p < .02), Lung Injury Score (p < .02), prothrombin time (p < .02), and activated partial thromboplastin time (p < .05). CONCLUSIONS: Hyperthermic isolated limb perfusion with recombinant TNF-alpha leads to high systemic concentrations of TNF-alpha, probably due to leakage of recombinant TNF-alpha from the perfusion circuit, mainly through collateral blood flow. A sepsis-like syndrome is seen in all patients. Despite high concentrations of systemic TNF-alpha, this sepsis syndrome is short-lived and recovery is rapid and complete in most patients.