Biliary excretion of ciprofloxacin and piperacillin in the obstructed biliary tract

Differential impact of incrementally elevated CA 19-9 levels on prognosis of resected pancreatic ductal adenocarcinoma

BACKGROUND

CA 19-9 is an extremely useful biomarker for pancreatic ductal adenocarcinomas (PDACs). However, the optimal cut-off and prognostic significance at higher cut-offs are yet to be determined.

METHODS

Retrospective analysis included patients with PDAC who underwent curative resection from January 2010 to May 2020 at Tata Memorial Centre, Mumbai. The pretherapy CA 19-9 was dichotomized using various cut-off levels and analysed.

RESULTS

In 244 included patients, the median overall survival (OS) for those with CA19-9 level (IU/ml) < or >78, 200, 500, 1000, and 2000 was 27, 24, 23, 22, 21 months versus 18, 16, 15, 14, 13 months; respectively, and was statistically significant (p-value- 0.002, 0.001, 0.002, 0.002 and 0.004, respectively). The number of recurrences and mortality had significant correlation with CA 19-9 cut-offs. On multivariate analysis, adjuvant treatment completion (p-0.004) and decreasing or stable CA19-9 after Neoadjuvant therapy (NAT) (p- 0.031) were associated with improved OS.

CONCLUSION

The prognostic significance of CA 19-9 was observed at all the cut-off levels examined, beyond mere elevated value as per the standard cut-off level. In patients with high CA19-9 level, surgery should be offered if technically and conditionally feasible, only when a response in CA19-9 level to NAT is achieved.

Hepatic impairment as a risk factor of adverse drug reactions

There are a lot of clinical variants of hepatic impairment ranging from asymptomatic increase in transaminases to acute liver failure and fulminant hepatitis. Hepatic impairment is a polietiologic syndrome. According to the epidemiological study conducted in the United States (19982008), the main causes of hepatic impairment were paracetamol overdose (46%), idiopathic liver dysfunction (14%), other drugs (excluding paracetamol, 11%), viral hepatitis B (7%), other infectious and non-infectious diseases with liver damage (except for viral hepatitis) 7%, autoimmune hepatitis (5%), ischemic hepatitis (syn. hypoxic hepatitis, liver infarction) 4%, viral hepatitis A (3%) and Wilson's disease (2%). Hepatic impairment have a direct impact on the pharmacokinetics and pharmacodynamics of drugs decreasing clearance, elimination and excretion of drugs. Also Transjugular intrahepatic porto-systemic shunts, which are often used to treat portal hypertension in patients with liver cirrhosis, can significantly reduce the presystemic elimination of drugs, thereby increasing their absorption. Moreover, in patients with liver cirrhosis, concomitant renal dysfunction also requires an adjustment of the dose of drugs. Correction of pharmacotherapy in accordance to pharmacokinetic and pharmacodynamic changes of drugs ingested by patients with impaired liver function will improve the quality of medical care and reduce the risks of adverse drug reactions.

Antibiotics in the Biliary Tract: A Review of the Pharmacokinetics and Clinical Outcomes of Antibiotics Penetrating the Bile and Gallbladder Wall

Biliary tract infections (BTIs), including cholangitis and cholecystitis, are common causes of bacteremia. Bacteremic BTIs are associated with a mortality rate of 9-12%. The extent to which antibiotics are excreted in the bile and the ratio of their exposure to the minimum inhibitory concentration of the infecting organism are among the important factors for the treatment of BTIs. This review updates health care professionals on the distribution of antibiotics in the common bile duct, gallbladder, and gallbladder wall. Antibiotic efficacy in treating BTIs based on the latest available clinical studies is also discussed. The efficacy and pharmacokinetics of 50 antibiotics are discussed. Overall, most antibiotic classes exhibit biliary penetration that translates into clinical efficacy. Only seven antibiotics (amoxicillin, cefadroxil, cefoxitin, ertapenem, gentamicin, amikacin, and trimethoprim/sulfamethoxazole) had poor biliary penetration profiles. Three antibiotics (ceftibuten, ceftolozane/tazobactam, and doripenem) had positive clinical outcomes despite the lack of pharmacokinetic studies on their penetration into the biliary tract. Conflicting efficacy data were reported for ampicillin despite adequate biliary penetration, whereas conflicting pharmacokinetic data were reported with cefaclor and moxifloxacin. Even in the absence of supportive clinical studies, antibiotics with good biliary penetration profiles may have a place in the treatment of BTIs.

Changes in causative pathogens of acute cholangitis and their antimicrobial susceptibility over a period of 6 years

BACKGROUND/AIMS

We evaluated changes of causative pathogen in acute cholangitis and their antimicrobial susceptibility over six years and differences between community-acquired and hospital-acquired acute cholangitis at our institution.

METHODS

Medical records of 1,596 patients with acute cholangitis and biliary drainage between August 2006 and August 2012 were reviewed retrospectively. Cases were divided according to time: period 1 (August 2006-December 2008, n=645, 40.4%), period 2 (January 2009-August 2012, n=951, 59.6%). Cases were divided according to community-acquired cholangitis (n=1,397, 87.5%) and hospital-acquired cholangitis (n=199, 12.5%). Causative pathogens and antimicrobial susceptibility were investigated in each group.

RESULTS

Causative pathogen was isolated from bile culture in 1,520 out of 1,596 cases (95.2%). The three most frequently isolated Gram-negative bacteria were extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli (n=485, 30.4%), E. coli (n=237, 13.2%), and Citrobacter freundii (n=110, 6.9%). Between periods 1 and 2, prevalence of ESBL-producing E. coli and Klebsiella pneumoniae did not show significant change (36.7% vs. 32.1%, p=0.073; 6.6% vs. 6.2%, p=0.732). C. freundii showed a significant increase from period 1 to period 2 (1.7% vs. 13.2%, p=0.000). In both time periods, imipenem was the antimicrobial agent showing the highest rate of susceptibility (93.3% vs. 93.9%, p=0.783). Higher prevalence of ESBL-producing E. coli and C. freundii was observed in the hospital-acquired cholangitis group (52.1% vs. 31.2%, p=0.000; 15.9% vs. 7.3%, p=0.001).

CONCLUSIONS

The most common causative pathogen of acute cholangitis was ESBL-producing E. coli. Prevalence of C. freundii increased over the time period. Imipenem should be reserved as an alternative for resistant pathogens.

Bacterial biliary tract infections in liver transplant recipients

PURPOSE OF REVIEW

The purpose of this study is to provide an overview of bacterial biliary tract infections in liver transplant recipients with a focus on pathogenesis and conservative treatment strategies.

RECENT FINDINGS

The development of interventional endoscopic and radiologic interventions has improved the outcome of conservative treatments for bile tract strictures and bilomas. However, recent data show an important rise of infections with multidrug-resistant (MDR) pathogens in liver transplant recipients.

SUMMARY

Both recurrent cholangitis and infected bilomas are bacterial biliary tract infections in liver transplant recipients responsible for significant morbidity and graft loss, which require a multidisciplinary approach. Risk factors for biliary tract strictures and bilomas formation have recently been identified. With the improved outcome of a conservative management including prolonged and/or recurrent antibiotic treatments, the risk of selecting resistant pathogens is increased. There is an urgent need to develop new strategies to reduce the risk of secondary infections by MDR isolates in liver transplant recipients.

Isolated microorganisms in plastic biliary stents placed for benign and malignant diseases

BACKGROUND

Biliary stenting is a well-established method to treat patients with malignant and benign biliary diseases. However, occlusion of plastic biliary stents is considered as a drawback and bacterial colonization seems to be the key factor in this process.

METHODS

During a 3-year period, 51 plastic biliary stents were extracted from 42 patients. Twenty three stents were inserted for treating malignant and 28 for benign diseases. Stent samples were taken under a strict protocol, and were immediately sent to microbiological laboratory for culturing.

RESULTS

A polymicrobial growth was present in nearly all stents. The most frequently isolated organisms were Enterococcus spp (74%), Escherichia coli (E. coli) (62%), and Klebsiella spp (58%). E. coli was more frequently encountered in benign vs. malignant disease (78% vs. 43%, P<0.05). Klebsiella spp, Pseudomonas spp, and Candida spp were more frequently isolated in occluded vs. non-occluded stents, 68% vs. 37%, 22% vs. 0 and 40% vs. 6% respectively (P<0.05). E. coli and Pseudomonas spp had 34% and 50% resistance rate to quinolones respectively. Enterobacter spp expressed Amp-C derepression in 35%. Enterococcus spp, Klebsiella spp and Pseudomonas spp had a low resistance rate.

CONCLUSION

Enterococcus spp, E. coli and Klebsiella spp are the most frequently associated organisms in plastic biliary stents. In occluded stents Pseudomonas spp and Candida spp should be taken into account. Quinolones may not be adequate for the treatment of cholangitis associated with stent occlusion. In patients under chemotherapy for malignancy and stent occlusion-related biliary sepsis, antifungal and enterococcal covering should be considered.

Infections of the biliary tract

Infection of the biliary tract, or cholangitis, is a potentially life-threatening condition. Bile duct stones are the most common cause of biliary obstruction predisposing to cholangitis. The key components in the pathogenesis of cholangitis are biliary obstruction and biliary infection. Several underlying mechanisms of bactibilia have been proposed. Characteristic clinical features of cholangitis include abdominal pain, fever, and jaundice. A combination of clinical features with laboratory tests and imaging studies are frequently used to diagnose cholangitis. Endoscopic retrograde cholangiopancreatography is the best diagnostic test. Less invasive imaging tests may be performed initially in clinically stable patients with uncertain diagnoses.

2013 WSES guidelines for management of intra-abdominal infections

Despite advances in diagnosis, surgery, and antimicrobial therapy, mortality rates associated with complicated intra-abdominal infections remain exceedingly high.The 2013 update of the World Society of Emergency Surgery (WSES) guidelines for the management of intra-abdominal infections contains evidence-based recommendations for management of patients with intra-abdominal infections.

Antimicrobial management of intra-abdominal infections: Literature's guidelines

Antimicrobial management of severe intra-abdominal infections (IAIs) involves a delicate balance of optimizing empirical therapy, which has been shown to improve clinical outcomes, while simultaneously reducing unnecessary antimicrobial use. Two sets of guidelines for the management of intra-abdominal infections were recently published. In 2010, the Surgical Infection Society and the Infectious Diseases Society of America (SIS-IDSA) created guidelines for the diagnosis and management of complicated IAIs. The new SIS-IDSA guidelines replace those previously published in 2002 and 2003. The World Society of Emergency Surgery (WSES) guidelines represent additional contributions, made by specialists worldwide, to the debate regarding proper antimicrobial drug methodology. These guidelines represent the conclusions of the consensus conference held in Bologna, Italy, in July 2010 during the first congress of the WSES.

Bile bacterial flora and its in vitro resistance pattern in patients with acute cholangitis resulting from choledocholithiasis

INTRODUCTION

Cholangitis and biliary sepsis are severe infectious diseases, which are often observed in patients with choledocholithiasis. The antimicrobial therapy is effective if started as soon as the diagnosis is made. Therefore, the profile of bile pathogens and its susceptibility to a number of antibiotics were evaluated.

MATERIAL AND METHODS

Bile cultures and antibiograms from 92 patients hospitalized between January 2006 and December 2008 in a tertiary referral center for the treatment of biliary and pancreatic diseases (Central Teaching Hospital, Medical University of Silesia) were reviewed. Specimens were obtained from patients with acute cholangitis and confirmed choledocholithiasis during endoscopic (i.e. ERCP) and surgical (i.e. percutaneus transhepatic biliary drainage) procedures. The bile specimens were examined for pathogenic aerobic and anaerobic bacteria and fungi.

RESULTS

Sixty-five of 92 analyzed cultures were positive. A total of 69 pathogens were isolated: 47 (68.1%) gram-negative bacteria, 18 (26.1%) gram-positive bacteria, 2 (2.9%) anaerobes and 2 (2.9%) Candida. The predominant gram-negative pathogens were Escherichia coli, Acinetobacter baumani complex, Klebsiella pneumoniae and Enterobacter cloacae. The most effective antibiotics against gram-negative bacteria were imipenem, cefoperazone/sulbactam, piperacillin/tazobactam and cefepime (susceptibility 97.9%, 89.4%, 85.1% and 85.1%, respectively). The expenditure on antibiotics monotherapies and combined therapies was also analyzed.

CONCLUSION

Our study shows that gram-negative bacteria were the predominant bile pathogens found in patients with acute cholangitis. Piperacillin/tazobactam or ceftazidime may be the alternative to ciprofloxacin therapeutic option. The addition of ticarcillin/clavulanic acid to ciprofloxacin could also be considered. However, imipenem should remain a back-up antibiotic in the treatment of acute cholangitis.

WSES consensus conference: Guidelines for first-line management of intra-abdominal infections

Intra-abdominal infections are still associated with high rate of morbidity and mortality.A multidisciplinary approach to the management of patients with intra-abdominal infections may be an important factor in the quality of care. The presence of a team of health professionals from various disciplines, working in concert, may improve efficiency, outcome, and the cost of care.A World Society of Emergency Surgery (WSES) Consensus Conference was held in Bologna on July 2010, during the 1st congress of the WSES, involving surgeons, infectious disease specialists, pharmacologists, radiologists and intensivists with the goal of defining recommendations for the early management of intra-abdominal infections.This document represents the executive summary of the final guidelines approved by the consensus conference.

[Acute cholangitis]

Acute cholangitis is a potentially severe infection of the biliary tract, resulting from a biliary obstruction. The most frequent cause of cholangitis is common duct stones. Biliary tract obstruction and secondary bacterial colonization lead to infection. In most cases, the causative agents are intestinal microflora, mostly aerobic microorganisms (and, to a lesser extent, anaerobic bacteria). The Charcot triad constitutes the most frequent symptomatology. Diagnosis is confirmed by means of radiological techniques, such as ultrasonography, computed tomography scan, or magnetic resonance imaging of the liver, in which signs of obstruction of the biliary tract can be detected and its etiology can often be determined. In most patients the treatment of choice is early appropriate antimicrobial therapy and biliary drainage, generally using endoscopic techniques.

Pharmacokinetics and dosage adjustment in patients with hepatic dysfunction

The liver plays a central role in the pharmacokinetics of the majority of drugs. Liver dysfunction may not only reduce the blood/plasma clearance of drugs eliminated by hepatic metabolism or biliary excretion, it can also affect plasma protein binding, which in turn could influence the processes of distribution and elimination. Portal-systemic shunting, which is common in advanced liver cirrhosis, may substantially decrease the presystemic elimination (i.e., first-pass effect) of high extraction drugs following their oral administration, thus leading to a significant increase in the extent of absorption. Chronic liver diseases are associated with variable and non-uniform reductions in drug-metabolizing activities. For example, the activity of the various CYP450 enzymes seems to be differentially affected in patients with cirrhosis. Glucuronidation is often considered to be affected to a lesser extent than CYP450-mediated reactions in mild to moderate cirrhosis but can also be substantially impaired in patients with advanced cirrhosis. Patients with advanced cirrhosis often have impaired renal function and dose adjustment may, therefore, also be necessary for drugs eliminated by renal exctretion. In addition, patients with liver cirrhosis are more sensitive to the central adverse effects of opioid analgesics and the renal adverse effects of NSAIDs. In contrast, a decreased therapeutic effect has been noted in cirrhotic patients with beta-adrenoceptor antagonists and certain diuretics. Unfortunately, there is no simple endogenous marker to predict hepatic function with respect to the elimination capacity of specific drugs. Several quantitative liver tests that measure the elimination of marker substrates such as galactose, sorbitol, antipyrine, caffeine, erythromycin, and midazolam, have been developed and evaluated, but no single test has gained widespread clinical use to adjust dosage regimens for drugs in patients with hepatic dysfunction. The semi-quantitative Child-Pugh score is frequently used to assess the severity of liver function impairment, but only offers the clinician rough guidance for dosage adjustment because it lacks the sensitivity to quantitate the specific ability of the liver to metabolize individual drugs. The recommendations of the Food and Drug Administration (FDA) and the European Medicines Evaluation Agency (EMEA) to study the effect of liver disease on the pharmacokinetics of drugs under development is clearly aimed at generating, if possible, specific dosage recommendations for patients with hepatic dysfunction. However, the limitations of the Child-Pugh score are acknowledged, and further research is needed to develop more sensitive liver function tests to guide drug dosage adjustment in patients with hepatic dysfunction.

Pharmacokinetics and dosage adjustment in patients with hepatic dysfunction

The liver plays a central role in the pharmacokinetics of the majority of drugs. Liver dysfunction may not only reduce the blood/plasma clearance of drugs eliminated by hepatic metabolism or biliary excretion, it can also affect plasma protein binding, which in turn could influence the processes of distribution and elimination. Portal-systemic shunting, which is common in advanced liver cirrhosis, may substantially decrease the presystemic elimination (i.e., first-pass effect) of high extraction drugs following their oral administration, thus leading to a significant increase in the extent of absorption. Chronic liver diseases are associated with variable and non-uniform reductions in drug-metabolizing activities. For example, the activity of the various CYP450 enzymes seems to be differentially affected in patients with cirrhosis. Glucuronidation is often considered to be affected to a lesser extent than CYP450-mediated reactions in mild to moderate cirrhosis but can also be substantially impaired in patients with advanced cirrhosis. Patients with advanced cirrhosis often have impaired renal function and dose adjustment may, therefore, also be necessary for drugs eliminated by renal exctretion. In addition, patients with liver cirrhosis are more sensitive to the central adverse effects of opioid analgesics and the renal adverse effects of NSAIDs. In contrast, a decreased therapeutic effect has been noted in cirrhotic patients with beta-adrenoceptor antagonists and certain diuretics. Unfortunately, there is no simple endogenous marker to predict hepatic function with respect to the elimination capacity of specific drugs. Several quantitative liver tests that measure the elimination of marker substrates such as galactose, sorbitol, antipyrine, caffeine, erythromycin, and midazolam, have been developed and evaluated, but no single test has gained widespread clinical use to adjust dosage regimens for drugs in patients with hepatic dysfunction. The semi-quantitative Child-Pugh score is frequently used to assess the severity of liver function impairment, but only offers the clinician rough guidance for dosage adjustment because it lacks the sensitivity to quantitate the specific ability of the liver to metabolize individual drugs. The recommendations of the Food and Drug Administration (FDA) and the European Medicines Evaluation Agency (EMEA) to study the effect of liver disease on the pharmacokinetics of drugs under development is clearly aimed at generating, if possible, specific dosage recommendations for patients with hepatic dysfunction. However, the limitations of the Child-Pugh score are acknowledged, and further research is needed to develop more sensitive liver function tests to guide drug dosage adjustment in patients with hepatic dysfunction.

In vitro activity of moxifloxacin and piperacillin/sulbactam against pathogens of acute cholangitis

AIM: To analyze the in vitro activity of moxifloxacin and piperacillin/sulbactam against pathogens isolated from patients with acute cholangitis.

METHODS: In this prospective study a total of 65 patients with acute cholangitis due to biliary stone obstruction (n = 7), benign biliary stricture (n = 16), and malignant biliary stricture (n = 42) were investigated with regard to spectrum of bacterial infection and antibiotic resistance. Pathogens were isolated from bile cultures in all study patients. In 22 febrile patients, blood cultures were also obtained. In vitro activity of moxifloxacin and piperacillin/sulbactam was determined by agar diffusion.

RESULTS: Thirty-one out of 65 patients had positive bile and/or blood cultures. In 31 patients, 63 isolates with 17 different species were identified. The predominant strains were Enterococcus species (26/63), E.coli (13/63) and Klebsiella species (8/63). A comparable in vitro activity of moxifloxacin and piperacillin/sulbactam was observed for E.coli and Klebsiella species. In contrast, Enterococcus species had higher resistances towards moxifloxacin. Overall bacteria showed antibiotic resistances in vitro of 34.9% for piperacillin/sulbactam and 36.5% for moxifloxacin.

CONCLUSION: Enterococcus species, E.coli and Klebsiella species were the most common bacteria isolated from bile and/or blood from patients with acute cholangitis. Overall, a mixed infection with several species was observed, and bacteria showed a comparable in vitro activity for piperacillin/sulbactam and moxifloxacin.

Effects of biliary obstruction on the penetration of ciprofloxacin and cefotaxime

OBJECTIVE

To evaluate the biliary penetration of ciprofloxacin and cefotaxime in patients with obstructed bile ducts and to determine simple predictive markers of effective biliary concentrations of these drugs.

METHODS

Sixty-two patients treated with endoscopic biliary drainage were prospectively included in a nonrandomized way and received intravenous ciprofloxacin (200 mg twice daily) or cefotaxime (1 g three times a day) for more than 24 h before exploration. Blood and bile samples were collected at the time of drainage. Ciprofloxacin and cefotaxime concentrations were measured using high-performance liquid chromatography. Biliary penetration was assessed by the bile-to-plasma ratio of the concentrations of both antibiotics.

RESULTS

Biliary penetration ranged from 0.06 to 42.7 for ciprofloxacin and from 0.01 to 1.14 for cefotaxime. The ratio was more than one in only 10 patients (35%) and three patients (9%) in ciprofloxacin and cefotaxime groups, respectively. Biliary concentration of the drug was more than 10 times the minimal inhibitory concentration in only 10 patients (35%) and in 12 patients (35%) in ciprofloxacin and cefotaxime groups, respectively. Serum bilirubin, alkaline phosphatase or gamma-glutamyl-transpeptidase were not good predictive markers of the biliary diffusion of the antibiotics.

CONCLUSION

In patients with obstructed bile ducts, the biliary penetration of ciprofloxacin is poor and reaches effective biliary concentrations in a minority of patients. Cefotaxime biliary penetration is even poorer. No liver test can predict accurately the biliary penetration of the drugs.

The use of adjusted preoperative CA 19-9 to predict the recurrence of resectable pancreatic cancer

BACKGROUND

Despite the usefulness of CA 19-9 in the diagnosis and prognosis of pancreatic cancer, cholestasis can falsely elevate CA 19-9 levels, which contributes to limited clinical utility in patients with biliary obstruction. This study was designed to evaluate the usefulness of adjusted preoperative CA 19-9 levels in predicting a prognosis of pancreatic cancer.

METHODS

The available medical records of patients with resected pancreatic cancer from January 1990 to June 2005 were retrospectively viewed at Yonsei Medical Center, Seoul, Korea. The adjusted CA 19-9 value was obtained by dividing the serum CA 19-9 level by the values of serum bilirubin in case of bilirubin greater, similar 2 mg/dL. Disease-free survival was evaluated according to the adjusted preoperative CA 19-9 value.

RESULTS

Sixty-one patients were investigated. Their adjusted preoperative CA 19-9 values were significantly different from the actual baseline CA 19-9 value (129.4 +/- 225.2 U/mL, versus 442.1 +/- 645.5 U/mL, P < 0.0001). On univariate analysis, peripancreatic microscopic invasion (P = 0.0142), lymphovascular invasion (P = 0.0038), and adjusted preoperative CA 19-9 > or = 50 U/mL (P = 0.0049) were predictive factors for cancer recurrence after curative resection. Adjusted preoperative CA 19-9 > or = 50 U/mL (Exp (B) = 2.097, P = 0.027) was an independent predictive factor in multivariate analysis.

CONCLUSIONS

The adjusted preoperative CA 19-9 value can predict the risk of recurrence after curative resection of pancreatic cancer. Interpreting the preoperative CA 19-9 value adjusted to the serum bilirubin values seems to be more reasonable in evaluating prognosis of pancreatic cancer.

Antimicrobial therapy for acute cholangitis: Tokyo Guidelines

Antimicrobial agents should be administered to all patients with suspected acute cholangitis as a priority as soon as possible. Bile cultures should be performed at the earliest opportunity. The important factors which should be considered in selecting antimicrobial therapy include the agent’s activity against potentially infecting bacteria, the severity of the cholangitis, the presence or absence of renal and hepatic diseases, the patient’s recent history of antimicrobial therapy, and any recent culture results, if available. Biliary penetration of the microbial agents should also be considered in the selection of antimicrobials, but activity against the infecting isolates is of greatest importance. If the causative organisms are identified, empirically chosen antimicrobial drugs should be replaced by narrower-spectrum antimicrobial agents, the most appropriate for the species and the site of the infection.

Bactobilia after liver transplantation: frequency and antibiotic susceptibility

After liver transplantation (LT), bactobilia occurs frequently in patients, leading in some cases to cholangitis and biliary sepsis. The present study is the first to investigate bactobilia after LT, and it gives an overview of predisposing factors for bactobilia, the microbial spectrum in the bile of LT patients, and the antibiotic susceptibility. A total of 172 endoscopic retrograde cholangiography (ERC) procedures were performed in 66 LT patients between 1 month and 5.8 years after LT. Bile samples were examined microbiologically. Sixty-eight nontransplanted patients without cholestasis, but requiring ERC for other reasons served as a control group. Of 172 samples obtained from LT patients, 126 (73.3%) were positive for microbes. A total of 236 organisms were isolated: 114 (48.3%) gram-positive bacteria, 92 (39.0%) aerobic gram-negative, 8 (3.4%) anaerobes, and 22 (9.3%) fungi. Ciprofloxacin and amoxycillin/clavulanic acid showed the best susceptibility results among oral antibiotics and piperacillin/tazobactam and imipenem/cilastatin among intravenous preparations. In contrast, only 15.7% of non-LT patients showed bactobilia. In conclusion, our study shows that bactobilia is a problem in patients after LT and that it is not only a contamination from endoscopic intervention. Mechanical obstruction, plastic stents, gallstones, and papillotomy increase the risk of bactobilia significantly. In our cohort we had the best antibiotic susceptibility results for positive cultures in LT patients with piperacillin/tazobactam, ciprofloxacin, or amoxycillin/clavulanic acid.

Biliary secretion of moxifloxacin in obstructive cholangitis and the non-obstructed biliary tract

BACKGROUND

Biliary secretion of antibiotic agents into the bile is considerably compromised by biliary obstruction, a precondition of bacterial cholangitis. Moxifloxacin may be advantageous according to secretion and antimicrobial spectrum.

AIM

To establish the secretion of moxifloxacin into obstructed and non-obstructed bile.

METHODS

Biliary excretion of moxifloxacin was determined in plasma and bile of 10 patients with biliary obstruction and cholangitis and 10 patients without biliary obstruction 30 min after administration of 400 mg of moxifloxacin intravenously.

RESULTS

The plasma concentration of moxifloxacin was similar in both groups (4.45 +/- 1.58 microg/mL; 4.33 +/- 1.23 microg/mL). The concentration of moxifloxacin in the bile was significantly lower in patients with biliary obstruction than without (4.63 +/- 3.94 microg/mL; range 0.71-14.40; vs. 16.90 +/- 13.77 microg/mL; range 1.79-42.50; P = 0.043). Although significantly different, the penetration index was extensively high in those without biliary obstruction (4.41 +/- 4.40; range 0.35-14.45) but still sufficient in those patients with obstructive cholangitis (1.02 +/- 0.74; range 0.29-2.83; P = 0.035).

CONCLUSION

These findings are suggestive of an active secretion mechanism for moxifloxacin into the obstructed bile, producing a biliary concentration sufficiently above the minimal inhibitory concentrations for most of the expected bacteria.

Microbiology of bile in patients with cholangitis or cholestasis with and without plastic biliary endoprosthesis

BACKGROUND

Cholangitis is a frequent complication of biliary stents. Empiric antibiotic selection is primarily based on bile cultures obtained from patients undergoing surgery and few data are available with respect to ERCP and biliary stents. This study analyzed the microbiology of bile and the antibiotic sensitivities of the organisms identified in patients presenting with clinical cholangitis or cholestasis.

METHODS

All bile cultures collected during ERCP from January 1994 to January 2000 were identified by using an ERCP database.

RESULTS

One hundred eighty cultures from 160 patients (mean age 55 years, range 6-94 years) were identified. Sixty-nine specimens were collected at ERCPs performed in patients with no biliary stent in place (group 1). One hundred eleven specimens were obtained from patients with a biliary stent in situ (group 2). The primary diagnoses for patients in groups 1 and 2 were as follows, respectively: malignant bile duct obstruction (25 and 85), choledocholithiasis (16 and 2), benign biliary strictures (6 and 18), acquired immunodeficiency syndrome (8 and 0), and miscellaneous (14 and 6). There were 38 positive bile cultures in group 1 (55%) and 109 positive cultures in group 2 (98%; p < 0.05). A higher frequency of polymicrobial infections (90%) was found in group 2 patients (vs. group 1, 45%; p < 0.001). Escherichia coli was the most common organism found in group 1 (17%); Enterococcus the most common in group 2 (31%). Among patients with positive bile cultures, bacteremia was more frequent in group 2 patients (46% vs. 21%; p < 0.05). Ciprofloxacin and cefiriaxone were the most effective antibiotics against identified gram-negative bacilli, and vancomycin against Enterococci.

CONCLUSION

In patients with cholangitis associated with biliary obstruction, the antibiotic selected initially should be active against gram-negative bacilli. Use of quinolones is recommended because these agents effectively penetrate an obstructed biliary tree and can be administered orally. Enterococci and polymicrobial infections are found more commonly in patients with a biliary stent than those without a stent. Pending definitive biliary decompression, patients with sepsis and those who do not quickly respond to treatment with a quinolone may benefit from the addition of antibiotic coverage against gram-positive organisms, targeted against Enterococci.

Acute (ascending) cholangitis

Cholangitis is an infection of an obstructed biliary system, most commonly due to common bile duct stones. Bacteria reach the biliary system either by ascent from the intestine or by the portal venous system. Once the biliary system is colonized, biliary stasis allows bacterial multiplication, and increased biliary pressures enable the bacteria to penetrate cellular barriers and enter the bloodstream. Patients with cholangitis are febrile, often have abdominal pain, and are jaundiced. A minority of patients present in shock with hypotension and altered mentation. There is usually a leukocytosis, and the alkaline phosphatase and bilirubin levels are generally elevated. Noninvasive diagnostic techniques include sonography, which is the recommended initial imaging modality. Standard CT, helical CT cholangiography, and magnetic resonance cholangiography often add important information regarding the type and level of obstruction. Endoscopic sonography is a more invasive means of obtaining high-quality imaging, and endoscopic or percutaneous cholangiography offers the opportunity to perform a therapeutic procedure at the time of diagnostic imaging. Endoscopic modalities currently are favored over percutaneous procedures because of a lower risk of complication. Treatment includes fluid resuscitation and antimicrobial agents that cover enteric flora. Biliary decompression is required when patients do not rapidly respond to conservative therapy. Definitive therapy can be performed by a surgical, percutaneous, or endoscopic route; the last is favored because it is the least invasive and has the lowest complication rate. Overall prognosis depends on the severity of the illness at the time of presentation and the cause of the biliary obstruction.

The effects of bile duct obstruction on the biliary secretion of ciprofloxacin in piglets

OBJECTIVE

The aim of this study was to evaluate the effect of bile duct obstruction on biliary secretion of ciprofloxacin and to look for useful parameters to guide clinical use of antibiotics in patients with acute cholangitis.

METHODS

Twenty-five Landrace piglets were used in this study. Their common bile ducts were ligated, with a duration ranging from 1 to 7 days. The changes of liver biochemical tests, intrabiliary pressure, diameter of common bile duct, and concentration of ciprofloxacin in bile were compared among the piglets with different severity of bile duct obstruction.

RESULTS

The bile-to-serum ratio of the ciprofloxacin concentration was 586.4% +/- 140.3% before the ligation of bile duct and was reduced significantly to 94.5% +/- 118.0% after 1-day obstruction. The biliary secretion of ciprofloxacin was greatly affected by the intrabiliary pressure in that the bile-to-serum ratio of ciprofloxacin concentration was reduced to 12.2% +/- 14.8% when the intrabiliary pressure reached to 32 cm H2O. The change in the intrabiliary pressure was correlated with the diameter of common bile duct, with a correlation coefficient of 0.90 (p < 0.001).

CONCLUSIONS

Biliary secretion of ciprofloxacin is decreased in proportion to the increase of intrabiliary pressure. In obstruction, a markedly dilated common bile duct usually indicates high intrabiliary pressure, and thus biliary concentrations of antibiotics will be lower than expected. Hence, our observations suggest that choosing an antibiotic with high antimicrobial activity, or establishing a biliary drainage to lower the intrabiliary pressure, would be beneficial for patients suffering from cholangitis with a dilated biliary tree.

Review article: antibiotic prophylaxis for endoscopic retrograde cholangiopancreatography (ERCP)

This review examines the evidence for antibiotic prophylaxis in endoscopic retrograde cholangiopan-creatography (ERCP), and provides detailed advice about suitable antibiotic regimens in appropriate high-risk patients. Ascending cholangitis and infective endocarditis are potential complications of endoscopic ERCP. The pathophysiology of these two complications is quite separate and different sub-groups of patients require prophylaxis with appropriate antibiotic regimens. Ascending cholangitis results from bacterial infection of an obstructed biliary system, usually from enteric Gram-negative microorganisms, resulting in bacteraemia. There is incomplete drainage of the biliary system after ERCP in up to 10% of patients who require stenting. Antibiotics started in these patients will probably reduce the frequency of cholangitis by 80%. If antibiotics are restricted to this group, approximately 90% of all patients having an ERCP will avoid antibiotics, but 80% of cholangitic episodes will be prevented. Infective endocarditis may result from the bacteraemia caused at the time of the ERCP in patients with an abnormal heart valve. Antibiotic prophylaxis, in particular covering alpha-haemolytic streptococci, should be started before the procedure in this defined high-risk group.

Biliary tract infections: a guide to drug treatment

Initial therapy of acute cholecystitis and cholangitis is directed towards general support of the patient, including fluid and electrolyte replacement, correction of metabolic imbalances and antibacterial therapy. Factors affecting the efficacy of antibacterial therapy include the activity of the agent against the common biliary tract pathogens and pharmacokinetic properties such as tissue distribution and the ratio of concentration in both bile and serum to the minimum inhibitory concentration for the expected micro-organism. Antimicrobial therapy is usually empirical. Initial therapy should cover the Enterobacteriaceae, in particular Escherichia coli. Activity against enterococci is not required since their pathogenicity in biliary tract infections remains unclear. Coverage of anaerobes, in particular Bacteroides spp., is warranted in patients with previous bile duct-bowel anastomosis, in the elderly and in patients in serious clinical condition. In patients with acute cholecystitis or cholangitis of moderate clinical severity, monotherapy with a ureidopenicillin--mezlocillin or piperacillin--is at least as effective as the combination of ampicillin plus aminoglycoside. In severely ill patients with septicaemia, an antibacterial combination is preferable. Therapy with aminoglycosides, mostly for Pseudomonas aeruginosa-related infections, should not exceed a few days because the risk of nephrotoxicity seems to be increased during cholestasis. Relief of biliary obstruction is mandatory, even if there is clinical improvement with conservative therapy, because cholangitis is most likely to recur with continued obstruction. Emergency invasive therapy is reserved for patients who fail to show a clinical response to antibacterial therapy within the first 36 to 48 hours or for those who deteriorate after an initial clinical improvement. Immediate surgery is indicated for gangrenous cholecystitis and perforation with peritonitis. Long-term administration of antibacterials is required for recurrent cholangitis, as seen in bile duct-bowel anastomosis. Oral cotrimoxazole (trimethoprim/sulfamethoxazole) is the preferred agent. Wound infection rates after biliary tract surgery can be significantly reduced by preoperative administration of prophylactic antibacterials. Newer generation beta-lactams have not proven to be of greater benefit than older agents such as cefuroxime or cefazolin. Antibacterial prophylaxis before endoscopic retrograde cholangiopancreatography (ERCP) should be reserved for patients with obstructive jaundice, since the risk of infectious complications seems to be strongly associated with this clinical condition. Failure to achieve full biliary drainage is the most important factor in predicting septicaemia, and prophylaxis should be prolonged until the bile duct is unobstructed. Piperacillin, cefazolin, cefuroxime, cefotaxime and ciprofloxacin are effective for this indication.