Renal failure complicating obstructive jaundice

The effect of bile duct manipulation and pair-feeding on peripheral vascular neuroeffector mechanisms: in vitro studies

Investigators studying the pathophysiological sequelae of bile duct ligation use different species of laboratory animals at varying postoperative times. There is also considerable variation in the type of control animal used for these experiments. In this study, we have attempted to validate our choice of the 3-day bile-duct-manipulated rat as the most appropriate control to study peripheral vascular neuroeffector mechanisms in bile-duct-ligated rats. We have compared the in vitro contractile response to norepinephrine in the absence and presence of cocaine, and the accumulation of the amine using 3H-norepinephrine of arterial rings and portal veins prepared from three different types of control rats--unoperated control, the 3-day bile-duct-manipulated and the 3-day pair-fed, bile-duct-manipulated rats. In vitro arterial reactivity to norepinephrine in the sham-operated rats was significantly attenuated and was associated with a cocaine-sensitive increase in norepinephrine uptake. Portal veins from the same animals showed no changes in in vitro reactivity to norepinephrine, although bile-duct manipulation and pair-feeding enhanced amine uptake. This study has demonstrated that bile-duct manipulation and pair-feeding attenuate in vitro vascular reactivity and enhance norepinephrine uptake. These in vitro changes are more pronounced in arterial tissue than venous tissue. In conclusion, these data indicate that bile-duct manipulation is the control of choice when measuring in vitro vascular neuroeffector mechanisms in 3-day bile-duct-ligated rats. Furthermore, these data emphasize the need to validate the control when experiments involving bile-duct ligation are undertaken.

Renal dysfunction in obstructive jaundice

The association between renal dysfunction and obstructive jaundice is well established. Despite a substantial number of clinical reviews and prospective studies, the exact incidence and extent of the problem has not been determined accurately. Various pathogenic mechanisms and therapeutic strategies have been proposed but renal dysfunction remains a persistent problem in hepatobiliary practice. The intention of this review is to determine the current extent of the problem, outline the proposed pathophysiological mechanisms and assess the current therapeutic options.

Increased renal susceptibility to gentamicin in the rat with obstructive jaundice. Role of lipid peroxidation

To study whether renal susceptibility to nephrotoxic stimuli is increased in obstructive jaundice, the effect of gentamicin on the renal function in bile duct-ligated rats was investigated. Gentamicin (50 mg/kg/day, subcutaneously) or saline was given to bile duct-ligated rats or sham-operated rats for six days. Mortality in the bile duct-ligated group that received gentamicin was 64% whereas that in the other groups was 0%. In the bile duct-ligated group, although serum creatinine and blood urea nitrogen were minimally affected, focal granulo-vacuolar degeneration in the proximal tubule was observed, which was accompanied by an increase in renal malondialdehyde. Gentamicin significantly increased serum creatinine and blood urea nitrogen levels and caused marked degeneration in the proximal tubule in the bile duct-ligated group, which was accompanied by a further increase in renal malondialdehyde, while these changes were not observed in the sham group. The kidney in obstructive jaundice appears to be susceptible to gentamicin. Enhanced production of oxygen radicals may be responsible for this effect.

Failure of macrophage activation in experimental obstructive jaundice: association with bacterial translocation

Bacterial translocation from the gastrointestinal tract and macrophage activation are central to current theories of sepsis. The relevance of both in obstructive jaundice is unclear. The effect of bile duct ligation for 7 days on bacterial translocation to mesenteric lymph nodes and on macrophage activation in a rat model was examined. Compared with an incidence of zero in sham-ligated controls, bile-duct ligated rats had a 67 per cent incidence of Gram-negative colonization of mesenteric lymph nodes. This was associated with a significant (P < 0.001) decrease in macrophage tumour necrosis factor, superoxide anion and nitric oxide production compared with that in sham controls. Spontaneous bacterial translocation occurs in experimental obstructive jaundice and is associated with marked suppression of macrophage activation. This suggests a mechanism whereby jaundiced patients may be more susceptible to persistent infection but relatively protected against uncontrolled sepsis.

Effects of ursodeoxycholic acid on hemodynamic and renal function abnormalities induced by obstructive jaundice in rats

The mechanism of renal function abnormalities in experimental biliary cirrhosis can be partially explained by the absence of gastrointestinal bile flow, which predisposes to translocation of intestinal endotoxin, a potent renal vasoconstrictor. Since bile acids prevent the absorption of intestinal endotoxins, we aimed to evaluate the effects of ursodeoxycholic acid (UDCA) administration on renal function and hemodynamic abnormalities induced by 1 week of obstructive jaundice in rats.

METHODS

Fifty-two rats were used; 30 had ligation of the common bile duct, 22 were sham operated. Bile duct ligated rats were randomly and blindly assigned to receive UDCA (25 mg/kg/day, n = 14) or placebo (n = 16) during 1 week. Sham rats received no treatment. Portal pressure (PP) as well as creatinine clearance (CrCl), urinary sodium (US), and plasma renin activity (PRA) were evaluated. Results are mean +/- SEM, with a significant value of p < 0.05.

RESULTS

Portal pressure (10.4 +/- 1.1 vs. 12.1 +/- 0.8 mm Hg) was significantly lower in UDCA than in placebo-treated rats. ALT serum levels were also significantly lower in bile duct ligated rats receiving UDCA (77.3 +/- 28 IU/L) than in placebo-treated rats (162 +/- 65 IU/L). US (1.1 +/- 0.5 vs. 2.1 +/- 0.3 mEq/24 h) was significantly lower and PRA (6.0 +/- 2.6 vs. 1.9 +/- 1.0 ng Ang 1/mL/h) higher in bile duct ligated than in sham-operated rats. No differences were found between UDCA or placebo-treated bile duct ligated rats. CrCl was similar between sham (0.39 +/- 0.12 mL/min/100 g BW) and UDCA (0.32 +/- 0.16) but significantly lower in placebo-treated (0.28 +/- 0.07) than sham-operated rats (p < 0.05).

CONCLUSION

UDCA administration had very mild effects on renal function abnormalities induced by experimental obstructive jaundice in rats. However, portal hypertension and biochemical abnormalities were partially improved.

Prospective study of postoperative renal function in obstructive jaundice and the effect of perioperative dopamine

A prospective study was undertaken to assess postoperative renal dysfunction in patients with obstructive jaundice and to determine the effectiveness of dopamine in reducing its incidence. A total of 23 patients undergoing surgical relief of obstructive jaundice (serum bilirubin level above 100 mumol l-1) were randomized into two groups. Those in the control group (n = 10) received 3 litres 5 per cent dextrose intravenously during the 24 h before surgery plus a bolus of intravenous frusemide 1 mg kg-1 at induction of anaesthesia. The second group (n = 13) received a similar fluid and frusemide regimen plus an infusion of dopamine 3 micrograms kg-1 min-1 starting at induction of anaesthesia and continuing for 48 h after surgery. Postoperative oliguria occurred in two of the ten patients in the control group and in three of the 13 given dopamine (P = 0.74). No patient developed acute renal failure. There was no significant difference in mean levels of serum bilirubin, urea and creatinine, creatinine clearance and 24-h urinary output, on the day before and on days 1-5 after operation, between the two groups. It is concluded that, with careful preoperative resuscitation and control of fluid and electrolyte balance, the incidence of postoperative renal dysfunction in patients with obstructive jaundice is not as high as in some previous studies and is unaltered by administration of perioperative low-dose dopamine.

Role of parenteral nutrition in preventing malnutrition and decreasing bacterial translocation to liver in obstructive jaundice

Surgery in patients with obstructive jaundice is associated with significant infectious complications probably due to impaired immune function and malnutrition. Total parenteral nutrition (TPN) may alleviate malnutrition but may also promote bacterial translocation (BT) from the gut. To elucidate if TPN can prevent malnutrition without promotion of BT in obstructive jaundice, 40 dogs underwent laparotomy for tissue sampling and placement of a central venous line and were allocated into one of four groups: I (PO-control) received dog chow and water ad libitum; II (PO-CBDL) underwent ligation of common bile duct (CBDL) and was fed dog chow; III (TPN-control) received TPN; and IV (TPN-CBDL) underwent CBDL and received TPN. Body weight, blood samples for liver function tests and bacterial culture, and tissues from liver and mesenteric lymph nodes (MLN) for quantitative bacterial culture and for histology were obtained prior to and 2 weeks after the experiment. The incidence of BT to MLN was 40% in the PO-CBDL and TPN-CBDL animals, which was significantly different from the other two groups (0%; p < 0.05). The incidence of BT to liver was 70% (7/10) in the PO-CBDL animals, which was significantly higher than that in groups I, III, and IV (0%, 20%, 20%, respectively) (p < 0.05). The PO-CBDL animals showed a significant decrease in body weight and prealbumin compatible with malnutrition, whereas the TPN-CBDL animals showed a significant increase in alkaline phosphatase and a consistent cholestasis on histology. The data suggest that TPN can prevent jaundice-associated malnutrition and decrease BT to liver but should be administered cautiously because it may precipitate cholestasis.

Effect of antitumour necrosis factor treatment on circulating tumour necrosis factor levels and mortality after surgery in jaundiced mice

Tumour necrosis factor (TNF) may play an important role in the increased incidence of complications after surgery in patients with obstructive jaundice. This study evaluated the effect of three different anti-TNF treatments, a monoclonal anti-TNF antibody (TN3), pentoxifylline and lactulose, on outcome after severe surgical trauma in mice with experimental biliary obstruction. Circulating serum TNF levels and mortality rate were monitored. Severe surgical trauma, such as renal ischaemia, in jaundiced mice resulted in increased levels of circulating TNF (3.5 ng/ml) and a high mortality rate (54 per cent). The three different anti-TNF treatments caused a significant reduction in postoperative levels of circulating TNF (TN3, P < 0.001; pentoxifylline, P < 0.01; lactulose, P < 0.05). Treatment with TN3 and pentoxifylline did not lead to a significantly reduced mortality rate (36 and 44 per cent respectively). Only lactulose treatment produced a significantly reduced mortality rate (7 per cent, P < 0.01). TNF is therefore not the only mediator responsible for death after surgery in jaundiced mice. Other mechanisms affected by lactulose are also involved.

Biliary drainage in obstructive jaundice: experimental and clinical aspects

Jaundiced patients undergoing invasive diagnostic and therapeutic procedures are at increased risk of complications and death. Despite the large number of clinical and experimental investigations carried out to identify relevant risk factors, no single parameter has been found to be consistently useful in predicting morbidity or mortality. Biliary decompression was initially employed by surgeons and subsequently by interventional radiologists. More recently, endoscopic retrograde cholangiopancreatography has provided an alternative route for decompression of the biliary tree and preliminary data using this method are encouraging. Although there are enthusiastic proponents of various therapeutic techniques, controlled trials have not been convincing in highlighting the benefits of biliary drainage or in determining the best approach. This article reviews the literature pertaining to this complex surgical problem; an attempt has been made to balance the advantages and disadvantages of biliary decompression as palliation and/or preliminary treatment for extrahepatic biliary obstruction.

Factors affecting morbidity and mortality in biliary tract surgery

Thirty-six clinical and laboratory parameters in 770 consecutive patients undergoing biliary tract surgery over a 3 year period were analyzed in an effort to define the patients at greatest risk. Twelve parameters had a significant correlation with hospital mortality, while multivariate analysis revealed that septic shock, malignant obstruction, serum albumin less than 3.0 gm%, history of hypertension, and plasma urea nitrogen greater than 20 mg% had an independent significance in predicting postoperative mortality. The presence of more than 2 of these risk factors identified a group of patients with an 18% mortality rate. It is for this group of patients that adequate pre-operative preparation such as fluid resuscitation, prophylactic antibiotics, and nutritional support are essential. The controversial preoperative biliary drainage might be only indicated in this group of patients.

Tumour necrosis factor alpha secretion in leporine endotoxaemia: role of the liver and effects of hepatic ischaemia

A leporine model to investigate tumour necrosis factor alpha (TNF alpha) secretion after peripheral vein or mesenteric vein lipopolysaccharide injection was devised. Mesenteric vein injection provoked lower arterial concentrations after 90 minutes (median (range), 2.81, (0.75-11.96) ng/ml) than peripheral vein injection (7.00 (4.27-14.95) ng/ml (p less than 0.05)). Mesenteric vein injection after 10 minutes' warm hepatic ischaemia, which impairs hepatic clearance, provoked higher median arterial TNF alpha values at 90 minutes (7.98 (2.85-21.48) ng/ml) than in normal animals (p less than 0.05). Portal vein endotoxaemia induced less TNF alpha production than systemic endotoxaemia unless hepatic clearance was impaired, thus the major source of TNF alpha in systemic endotoxaemia is probably extrahepatic.

Complications in obstructive jaundice: role of endotoxins

Surgical treatment of patients with obstructive jaundice is associated with a high postoperative morbidity and mortality. A correlation was suggested between endotoxins and the observed complications. The mechanism by which endotoxins affect the negative outcome in operated jaundiced patients was, however, not clear, nor was the mechanism of clinically used preventive treatments. Several experiments were therefore performed in rats with biliary obstruction, to investigate whether and how endotoxins are active. The role of endotoxins was studied in a model in which endotoxins were absent. In germfree rats (free of bacteria and thus of endotoxin) the effect of biliary obstruction was studied and compared with biliary obstruction in conventional rats. To substantiate further the role of endotoxin, anti-endotoxin treatments (oral lactulose or internal drainage) were tested in rats with obstructive jaundice undergoing a severe surgical trauma. It is shown that endotoxins are responsible for complications (suppression of cellular immunity, kidney function, mortality) and that these complications can be prevented with an anti-endotoxin treatment. These results may have implications for preoperative treatment of jaundiced patients.

Role of renal sympathetic nerve activity in renal failure associated with obstructive jaundice in the rat

The propensity for renal failure associated with obstructive jaundice and liver disease may be related to enhanced vasoconstriction of the renal vascular bed with resultant decreases in renal blood flow. Renal sympathetic nervous activity may be a mediator of this effect. The increased renal production of prostaglandins which has been observed in previous models of bile duct ligation may serve to counterbalance the effects of such vasoconstricting influences. This study was undertaken to assess the effect of bile duct ligation on renal function and prostaglandin production in the rat. Furthermore, this study was designed to determine if renal sympathetic nerve activity contributes to the development of renal failure after bile duct ligation. Sprague-Dawley rats underwent either sham operation (n = 8), bilateral renal denervation (n = 10), bile duct ligation alone (n = 11), or bile duct ligation and bilateral renal denervation (n = 10). Renal function was assessed before and 4 days after operation. Bile duct ligation resulted in a 46% decrease in creatinine clearance (p less than 0.01), a 33% decrease in urinary sodium excretion (p less than 0.01), a twofold increase in urine flow (p less than 0.01), and twofold increases in urinary excretion of PGE2, 6-keto-PGF1 alpha, and thromboxane B2 (p less than 0.01). Renal denervation did not prevent the decreases in creatinine clearance and sodium excretion seen after bile duct ligation and had no effect on the changes in urine flow and prostaglandin excretion. These findings demonstrate that bile duct ligation in the rat results in impaired renal function, accompanied by increases in renal prostaglandin production. In addition, this study indicates that the perturbations in renal function and renal prostaglandin production induced by bile duct ligation are not mediated by renal sympathetic nerve activity.

Prevention of postoperative renal dysfunction in patients with obstructive jaundice: a multicentre study of bile salts and lactulose

The role of preoperative lactulose and bile salts in the prevention of postoperative renal failure in patients with obstructive jaundice has been evaluated in a prospective randomized trial. One hundred and two patients undergoing surgery for obstructive jaundice (bilirubin greater than 100 mumols/l) were randomized into three groups: those receiving preoperative oral lactulose (n = 35), those receiving oral sodium deoxycholate (n = 32) and a control group of patients receiving no specific treatment (n = 35). All patients received intravenous fluids commencing the night before surgery. One patient in the control group and none in the treatment groups developed postoperative renal failure. Postoperative deterioration of renal function in patients with normal preoperative function was significantly more common in the control group than in the treatment groups (chi 2 = 8.1, d.f. = 2, P less than 0.02). The incidence of renal failure and impairment was lower in this control group than that reported in previous studies. This may be due to the introduction of adequate preoperative hydration. Additional protection occurs by the preoperative administration of either lactulose or sodium deoxycholate.

Renal function in obstructive jaundice in man: cholangiocarcinoma model

Renal function with respect to water clearance and renal hemodynamics was studied in 15 patients with obstructive jaundice due to cholangiocarcinoma. The results were compared with those of the control normal subjects. There was no change in renal function in the patients with mild to moderate jaundice, with total serum bilirubin from 8.0 to 15.1 mg/dl. Increased urinary sodium excretion and decreased free water and negative water clearances were observed in the patients with severe jaundice with total serum bilirubin from 27.0 to 40.4 mg/dl and normal serum albumin. Renal blood flow was normal, but creatinine clearance was decreased. In severely jaundiced patients with serum bilirubin from 30.5 to 40.1 mg/dl and hypoalbuminemia urinary sodium excretion, free water clearance, negative water clearance, renal blood flow and creatinine clearance were decreased. There was salt and water retention in this group. The findings suggest that in severe jaundice there is inhibition of sodium chloride reabsorption in the thick ascending limb of Henle's loop. ADH and increased hydraulic conductivity of the collecting tubules possibly contribute to decreased free water clearance. In severely jaundiced patients with hypoalbuminemia this salt losing effect is converted to salt retention by increased proximal tubular reabsorption of sodium.

Prevention of postoperative complications in jaundiced rats. Internal biliary drainage versus oral lactulose

In an experiment mimicking a severe surgical trauma by deliberate renal ischemia, the postoperative outcome in jaundiced rats was studied. Intervention studies were performed with preoperative oral lactulose (to reduce endotoxin toxicity) or preoperative internal biliary drainage. Compared to control, obstructive jaundice in rats significantly reduced survival time (p less than 0.001) and enhanced renal impairment (p less than 0.001) after renal ischemia. Preoperative supportive therapy of jaundiced rats with oral lactulose increased survival time (p less than 0.01) but did not reduce deterioration of renal function. Preoperative internal biliary drainage proved to be superior, with a significant reduction of renal impairment (p less than 0.001) and an improved survival time (p less than 0.001). Our experiments provide further evidence that obstructive jaundice increases the complication rate following major surgical procedures. Based on our results in rats, we suggest that in obstructive jaundice preoperative internal biliary drainage is the supportive therapy of choice. However, if adequate drainage is not possible, oral treatment with lactulose may help reduce postoperative complications.

Gut barrier function and the surgeon

There is accumulating evidence that multiple organ failure is not always the result of an established septic focus. Increasing attention has centred on the gut as a reservoir of bacteria (and bacterial endotoxins) that can traverse the intestinal mucosal barrier (a process called 'bacterial translocation') and initiate the septic state. Although the link between haemorrhagic shock and sepsis was recognized decades ago, the full experimental demonstration of this phenomenon is more recent. It was shown to occur in three main settings: physical disruption of the gut mucosa, impaired defence mechanisms and altered gut microbial ecology. Conditions such as haemorrhagic shock, burns, protein malnutrition and sepsis are seen in the severely ill surgical patient or the multiply injured, and are known to cause various combinations of circumstances favourable to bacterial translocation and endotoxin absorption. These may play an important role in the mortality of the critically ill.