The penetration of antibiotics into human pancreas

Selective and Concentrative Enteropancreatic Recirculation of Antibiotics by Pigs

Antibiotics that are efficacious for infectious pancreatitis are present in pancreatic exocrine secretion (PES) after intravenous administration and above minimal inhibitory concentrations. We measured concentrations of four antibiotics by tandem liquid chromatography-mass spectroscopy in plasma and PES after enteral administration to juvenile pigs with jugular catheters and re-entrant pancreatic-duodenal catheters. Nystatin, which is not absorbed by the intestine nor used for infectious pancreatitis (negative control), was not detected in plasma or PES. Concentrations of amoxicillin increased in plasma after administration (p = 0.035), but not in PES (p = 0.51). Metronidazole and enrofloxacin that are used for infectious pancreatitis increased in plasma after enteral administration and even more so in PES, with concentrations in PES averaging 3.1 (±0.5)- and 2.3 (±0.6)-fold higher than in plasma, respectively (p's < 0.001). The increase in enrofloxacin in PES relative to plasma was lower after intramuscular administration (1.8 ± 0.5; p = 0.001). The present results demonstrate the presence of a selective and concentrative enteropancreatic pathway of secretion for some antibiotics. Unlike the regulated secretion of bile, the constitutive secretion of PES and intestinal reabsorption may provide a continuous exposure of pancreas tissue and the small intestine to recirculated antibiotics and potentially other therapeutic molecules. There is a need to better understand the enteropancreatic recirculation of antibiotics and the associated mechanisms.

Vancomycin Concentrations in Necrotic Pancreatic Tissue: A Pilot Study

Purpose:

To determine vancomycin concentrations in necrotic pancreatic tissue of intensive care unit (ICU) patients with acute necrotizing pancreatitis.

Methods:

The prospective, observational pilot study was conducted at a university-based tertiary hospital. The patient population consisted of 11 patients with necrotizing pancreatitis receiving vancomycin and undergoing necrosectomy. Tissue samples taken during surgical debridement were assayed for vancomycin by immunoassay. Patients were divided into steady state and nonsteady-state groups. Two patients were excluded because necrosectomy was not performed, and one tissue sample could not be assayed because of contamination.

Results:

The mean tissue concentration was 5.84 mcg/mL (ranging from 3.1 mcg/mL to 8.94 mcg/mL). Four patients in the nonsteady-state group, who each received a single dose of vancomycin, had a mean tissue concentration of 4.5 ± 1.68 mcg/mL, compared with 7.76 ± 1.05 mcg/mL for the four steady-state patients.

Conclusion:

The data shows that vancomycin is detectable in necrotic pancreas tissue but possibly not in concentrations sufficient to prevent or treat bacterial contamination in patients with pancreatic necrosis.

The role of open necrosectomy in the current management of acute necrotizing pancreatitis: a review article

The optimal management of necrotizing pancreatitis continues to evolve. Currently, conservative intensive care treatment represents the primary therapy of acute severe necrotizing pancreatitis, aiming at prevention of organ failure. Following this mode of treatment most patients with sterile necroses can be managed successfully. Surgery might be considered as an option in the late phase of the disease for patients with proven infected pancreatic necroses and organ failure. For these patients surgical debridement is still considered the treatment of choice. However, even for this subgroup of patients, the concept of operative strategy has been recently challenged. Nowadays, it is generally accepted that necrotizing pancreatitis with proven infected necroses as well as septic complications directly caused by pancreatic infection are strong indications for surgical management. However, the question of the most appropriate surgical technique for the treatment of pancreatic necroses remains unsettled. At the same time, recent advances in radiological imaging, new developments in interventional radiology, and other minimal access interventions have revolutionised the management of necrotizing pancreatitis. In light of these controversies, the present paper will focus on the current role of surgery in terms of open necrosectomy in the management of severe acute necrotizing pancreatitis.

Pancreatitis in inflammatory bowel diseases

Crohn's disease and ulcerative colitis, together popularly known as inflammatory bowel disease (IBD), are characterized by a number of extraintestinal manifestations. Although infrequent, acute pancreatitis, and less often chronic pancreatitis, may occur as a result of the disease itself or secondary to the medications used in the treatment. The increased incidence of acute pancreatitis in Crohn's disease can be explained based on the high predisposition to cholesterol as well as pigment stones as a result of ileal disease, anatomic abnormalities of the duodenum, immunologic disturbances associated with IBD, and, above all, to the side effects of many medications used in the treatment. Sulfasalazine, 5-aminosalicylic acid, azathioprine, and 6-mercaptopurine are well known to cause acute pancreatitis as a result of a possible idiosyncratic mechanism. Crohn's disease and ulcerative colitis share many clinical manifestations and treatment modalities. Nonspecific elevations of serum pancreatic enzymes in IBD make it difficult to avoid over diagnosis of acute pancreatitis, particularly in patients with Crohn's disease who suffer from abdominal pain often. The IBD-pancreas association is further reflected in many reports of exocrine as well as endocrine pancreatic insufficiency.

[Antibiotic therapy in acute pancreatitis]

Infected pancreatic necrosis (IPN) is one of the main causes of mortality in patients with acute pancreatitis (AP). The choice of antibiotic therapy in AP should be based on penetration of the drug in the pancreas and the degree of coverage provided against the typical bacterial flora produced in IPN. Drugs such as imipenem, ciprofloxacin and metronidazole have been widely studied and seem to be ideal in the treatment of INP. Clinical practice guidelines recommend a carbapenem agent as the initial empirical treatment. When Gram-positive pathogens are isolated in pancreatic samples, vancomycin can be used alone or associated with a carbapenem. Currently, prophylactic antibiotic therapy for IPN is not supported by the scientific evidence, since both the best quality studies (double-blind) and the latest meta-analysis published have found no benefit of the use of this strategy.

Deferoxamine and meropenem combination therapy in experimental acute pancreatitis

INTRODUCTION

Recent data from the experimental clinical studies suggest that antibiotics having good penetration to pancreas may reduce mortality by preventing pancreatic infection, which is the most important prognostic factor in acute pancreatitis (AP). Deferoxamine is an active free oxygen radical scavenger, which has been shown to have a protective role in development of acute pancreatitis.

AIM

To determine the effects of combination of deferoxamine and meropenem in acute necrotizing pancreatitis.

METHODOLOGY

One hundred male Sprague-Dawley rats were randomly divided into 5 groups. All rats underwent laparotomy with cannulation of biliopancreatic duct. Group 1 received intraductal saline injection. Acute necrotizing pancreatitis was induced in group 2, 3, 4, and 5 by intraductal injection of 3% taurocholate. Group 1 (sham operated) and group 2 were injected with saline of 0.3 mL/kg intraperitoneally (i.p). Group 3 was injected with meropenem 60 mg/kg/d i.p, group 4 with deferoxamine 80 mg/kg/d s.c and group 5 with combination of these 2 agents at the same doses. While meropenem was started 2 hours later, all treatments were started immediately after the induction of pancreatitis. All rats were killed at the 48th hour of the treatment and blood and tissue samples were collected for amylase determinations, pathologic examinations, and culture.

RESULTS

There was no difference in serum amylase levels between AP induced groups (P > 0.05). Pancreatic histology scores were significantly low in rats treated with deferoxamine (group 4), and combination regimen (group 5) (P < 0.001). Meropenem significantly reduced the incidence of pancreatic infection. Although combination of deferoxamine with meropenem showed better effects than meropenem alone in terms of pancreatic infection, the difference did not reach to statistical significance.

CONCLUSIONS

Meropenem treatment reduces secondary pancreatic infections in acute pancreatitis. Treatment with deferoxamine and meropenem combination may be more beneficial than single therapies in reducing the severity of pancreatitis. Further studies investigating the effects of this combination on survival are needed.

Is late antibiotic prophylaxis effective in the prevention of secondary pancreatic infection?

BACKGROUND

Secondary infection of the inflamed pancreas is the principal cause of death after severe acute pancreatitis (AP). Although patients are not always managed early in the course of AP in clinical practice, prophylactic antibiotics that were used in experimental studies in rats were always initiated early after induction of pancreatitis. The effectiveness of antibiotics initiated later is unknown.

AIM

The aim of this study was to compare the effectiveness of ciprofloxacin and meropenem initiated early versus later in the course of acute necrotizing pancreatitis (ANP) in rats.

METHODS

100 Sprague-Dawley rats were studied. ANP was induced in rats by intraductal injection of 3% taurocholate. Rats were divided randomly into five groups: group I rats received normal saline as a placebo, group II and IV rats received three times daily meropenem 60 mg/kg i.p. at 2 and 24 h, respectively and group III and V rats received twice daily ciprofloxacin 50 mg/kg i.p. at 2 and 24 h, respectively, after induction. At 96 h, all rats were killed for quantitative bacteriologic study. A point-scoring system of histological features was used to evaluate the severity of pancreatitis.

RESULTS

Meropenem and ciprofloxacin initiated 2 h after induction of pancreatitis significantly reduced the prevalence of pancreatic infection (p < 0.001 and p < 0.04, respectively) as compared to controls. Neither of the antibiotics initiated later during the course of AP caused a significant decrease in pancreatic infection in rats (p > 0.05). Although the rats treated early infected less frequently than the rats treated later, the comparison reached statistical significance only in the meropenem group (p < 0.02).

CONCLUSION

Early antibiotic treatment reduces pancreatic infection more efficiently than late antibiotic treatment in ANP in rats.

Cefepime tissue penetration in experimental acute pancreatitis

INTRODUCTION

Antibiotic treatment represents a cornerstone in the management of severe acute pancreatitis. However, different antibiotic substances are currently used. In this study, we analyzed penetration of cefepime into pancreatic tissue in two models of acute pancreatitis.

AIMS AND METHODOLOGY

Following induction of acute pancreatitis, animals were treated with a single intravenous dose of cefepime (0.1 mg/g of body weight). At two different time points, blood and tissue samples were obtained for determination of cefepime concentration and microbiologic analysis.

RESULTS

Mean pancreatic tissue concentrations +/- SEM 30 minutes after drug administration were significantly higher in animals with either mild acute pancreatitis (113 +/- 22 mg/kg) or severe acute pancreatitis (75 +/- 22 mg/kg) than in control animals (30 +/- 6 mg/kg) (p < 0.005). The minimal inhibitory concentrations (MIC90) for organisms usually isolated from infected pancreatic necrosis vary between 0.05 and 8 mg/L, which is between nine and 1,500 times lower than the mean peak concentration found in necrotic pancreatic tissue. Seven hours 30 minutes after antibiotic administration, pancreatic cefepime concentrations were still above the MIC90 in 100% and 83% of animals with mild and severe disease, respectively. The infection rate of pancreatic tissue was significantly lower after antibiotic treatment and was similar after imipenem/cilastatin or cefepime treatment.

CONCLUSION

Because of its antibacterial coverage and proven tissue penetration in acute pancreatitis, cefepime should be studied in patients with severe acute pancreatitis.

Acute and chronic pancreatitis

Acute pancreatitis has multiple causes, an unpredictable course, and myriad complications. The diagnosis relies on a combination of history, physical examination, serologic markers, and radiologic findings. The mainstay of therapy includes aggressive hydration, maintenance of NPO, and adequate analgesia with narcotics. Antibiotic and nutritional support with total parenteral nutrition should be used when appropriate.

Infection prevention in necrotizing pancreatitis: an old challenge with new perspectives

Necrotizing pancreatitis still remains a life-threatening disease despite several improvements in diagnosis, prevention and treatment. In recent years, some important questions have been answered such as the need for early intensive medical treatment rather than early surgery, but others are still strongly debated. The aim of this paper is to present an up-to-date assessment of current challenges in the management of necrotizing pancreatitis in order to prevent infection.

Fluconazole penetration into the pancreas

Because of antibiotic prophylaxis for necrotizing pancreatitis, the frequency of fungal superinfection in patients with pancreatic necrosis is increasing. In this study we analyzed the penetration of fluconazole into the human pancreas and in experimental acute pancreatitis. In human pancreatic tissues, the mean fluconazole concentration was 8.19 +/- 3.38 microg/g (96% of the corresponding concentration in serum). In experimental edematous and necrotizing pancreatitis, 88 and 91% of the serum fluconazole concentration was found in the pancreas. These data show that fluconazole penetration into the pancreas is sufficient to prevent and/or treat fungal contamination in patients with pancreatic necrosis.

Management of Pancreatitis

Acute pancreatitis can be mild or severe. Identifying causes helps in preventing recurrent episodes, management of complications, treatment of the underlying disorder, and/ or removal of an etiologic agent. Supportive care, pain control, nutrition, and antibiotic use are discussed. Overall, the goal is to prevent and minimize complications and reduce mortality. Chronic pancreatitis is complex, and the etiology of the abdominal pain is multifactorial. The goal is to eliminate causes and treat underlying disorders that may contribute to the inflammatory process. Management of pain, pancreatic insufficiency, and complications is essential. If medical management is not successful, surgical options should be considered.

Surgical approach in patients with acute pancreatitis. Is infected or sterile necrosis an indication--in whom should this be done, when, and why?

The morbidity and mortality rates of severe acute pancreatitis are related to the degree of pancreatic necrosis that accompanies the attack and to the presence of infection. The decision about whether and when to operate on these patients is often difficult, and it requires mature clinical judgment. Proven infection of pancreatic necrosis is an absolute indication for surgical intervention, at which time surgical doffebridement and drainage should be performed. Most patients with sterile necrosis eventually respond to conservative nonsurgical medical management. In patients who remain critically ill for weeks or whose clinical course deteriorates despite maximal intensive care, surgery may be appropriate. Even when these guidelines are followed, the mortality (15% to 40%) and morbidity (approximately 80%) rates remain high.

Nonsurgical management of acute pancreatitis. Use of antibiotics

In severe AP, infected necrosis is the leading cause of death. Prevention of pancreatic infection is the major goal in the treatment of patients with necrotizing pancreatitis. Adequate early antibiotic therapy seems to be promising in these patients. Their role and the optimal timing of the antibiotic therapy (e.g., benefit of prophylactic application) are discussed. Preliminary results of a study in patients with infected pancreatic necrosis and exclusively or primarily conservative treatment also are presented.

Pharmacokinetics and pharmacodynamics of the nitroimidazole antimicrobials

Metronidazole, the prototype nitroimidazole antimicrobial, was originally introduced to treat Trichomonas vaginalis, but is now used for the treatment of anaerobic and protozoal infections. The nitroimidazoles are bactericidal through toxic metabolites which cause DNA strand breakage. Resistance, both clinical and microbiological, has been described only rarely. Metronidazole given orally is absorbed almost completely, with bioavailability > 90% for tablets; absorption is unaffected by infection. Rectal and intravaginal absorption are 67 to 82%, and 20 to 56%, of the dose, respectively. Metronidazole is distributed widely and has low protein binding (< 20%). The volume of distribution at steady state in adults is 0.51 to 1.1 L/kg. Metronidazole reaches 60 to 100% of plasma concentrations in most tissues studied, including the central nervous system, but does not reach high concentrations in placental tissue. Metronidazole is extensively metabolised by the liver to 5 metabolites. The hydroxy metabolite has biological activity of 30 to 65% and a longer elimination half-life than the parent compound. The majority of metronidazole and its metabolites are excreted in urine and faeces, with less than 12% excreted unchanged in urine. The pharmacokinetics of metronidazole are unaffected by acute or chronic renal failure, haemodialysis, continuous ambulatory peritoneal dialysis, age, pregnancy or enteric disease. Renal dysfunction reduces the elimination of metronidazole metabolites; however, no toxicity has been documented and dosage alterations are unnecessary. Liver disease leads to a decreased clearance of metronidazole and dosage reduction is recommended. Recent pharmacodynamic studies of metronidazole have demonstrated activity for 12 to 24 hours after administration of metronidazole 1 g. The post-antibiotic effect of metronidazole extends beyond 3 hours after the concentration falls below the minimum inhibitory concentration (MIC). The concentration-dependent bactericidal activity, prolonged half-life and sustained activity in plasma support the clinical evaluation of higher doses of metronidazole given less frequently. Metronidazole-containing regimens for Helicobacter pylori in combination with proton pump inhibitors demonstrate higher success rates than antimicrobial regimens alone. The pharmacokinetics of metronidazole in gastric fluid appear contradictory to these results, since omeprazole reduces peak drug concentration and area under the concentration-time curve for metronidazole and its hydroxy metabolite; however, concentrations remain above the MIC. Other members of this class include tinidazole, ornidazole and secnidazole. They are also well absorbed and distributed after oral administration. Their only distinguishing features are prolonged half-lives compared with metronidazole. The choice of nitroimidazole may be influenced by the longer administration intervals possible with other members of this class; however, metronidazole remains the predominant antimicrobial for anaerobic and protozoal infections.

Antibiotic prophylaxis in the initial management of severe acute pancreatitis

BACKGROUND

The role of antibiotic prophylaxis in the initial management of patients with acute pancreatitis is an area of major controversy. Contrary to earlier clinical trials, recent experimental and clinical studies have accrued evidence that warrants reappraisal of current clinical practice. This article reviews these recent advances in knowledge.

METHODS

All papers derived from a Medline search for the years 1990-1997 inclusive using the text words 'acute', 'pancreatitis', 'antibiotic' and 'antibiotics' were studied. Additional papers were derived from reference lists within papers identified by the Medline search. Only experimental and clinical papers relevant to the issue of prophylactic antibiotic therapy in acute pancreatitis are included in the review.

RESULTS AND CONCLUSION

Current experimental evidence favours the use of prophylactic antibiotics in severe acute pancreatitis. The results of contemporary randomized clinical trials restricted to patients with prognostically severe acute pancreatitis have demonstrated improvement in outcome associated with antibiotic treatment.

Metronidazole. A therapeutic review and update

The nitroimidazole antibiotic metronidazole has a limited spectrum of activity that encompasses various protozoans and most Gram-negative and Gram-positive anaerobic bacteria. Metronidazole has activity against protozoans like Entamoeba histolytica, Giardia lamblia and Trichomonas vaginalis, for which the drug was first approved as an effective treatment. Anaerobic bacteria which are typically sensitive are primarily Gram-negative anaerobes belonging to the Bacteroides and Fusobacterium spp. Gram-positive anaerobes such as peptostreptococci and Clostridia spp. are likely to test sensitive to metronidazole, but resistant isolates are probably encountered with greater frequency than with the Gram-negative anaerobes. Gardnerella vaginalis is a pleomorphic Gram-variable bacterial bacillus that is also susceptible to metronidazole. Helicobacter pylori has been strongly associated with gastritis and duodenal ulcers. Classic regimens for eradicating this pathogen have included metronidazole, usually with acid suppression medication plus bismuth and amoxicillin. The activity of metronidazole against anaerobic bowel flora has been used for prophylaxis and treatment of patients with Crohn's disease who might develop an infectious complication. Treatment of Clostridium difficile-induced pseudomembraneous colitis has usually been with oral metronidazole or vancomycin, but the lower cost and similar efficacy of metronidazole, coupled with the increased concern about imprudent use of vancomycin leading to increased resistance in enterococci, have made metronidazole the preferred agent here. Metronidazole has played an important role in anaerobic-related infections. Advantages to using metronidazole are the percentage of sensitive Gram-negative anaerobes, its availability as oral and intravenous dosage forms, its rapid bacterial killing, its good tissue penetration, its considerably lower chance of inducing C. difficile colitis, and expense. Metronidazole has notable effectiveness in treating anaerobic brain abscesses. Metronidazole is a cost-effective agent due to its low acquisition cost, its pharmacokinetics and pharmacodynamics, an acceptable adverse effect profile, and its undiminished antimicrobial activity. While its role as part of a therapeutic regimen for treating mixed aerobic/anaerobic infections has been reduced by newer, more expensive combination therapies, these new combinations have not been shown to have any therapeutic advantage over metronidazole. Although the use of metronidazole on a global scale has been curtailed by newer agents for various infections, metronidazole still has a role for these and other therapeutic uses. Many clinicians still consider metronidazole to be the 'gold standard' antibiotic against which all other antibiotics with anaerobic activity should be compared.

Surgical treatment of infected necrosis

Over the years, experience has shown that the cornerstone for improved survival in patients with infected pancreatic necrosis is an early, precise diagnosis followed by adequate drainage combined with modern intensive care management. In experienced hands, this goal can be achieved with different surgical approaches, provided that all septic collections are thoroughly removed and that reexploration is performed promptly if there is evidence of ongoing sepsis. If there is any concept preferable, and under what conditions, future large-scale randomized trials with precise and comparable patient stratification will have to demonstrate it.

Antimicrobial activity of human pancreatic juice and its interaction with antibiotics

Pancreatic juice (PJ) should be a factor of variability in the antimicrobial activity of antibiotics eliminated by the pancreas during pancreatic infections. We studied its effects on the activity of antimicrobial drugs with different mechanisms of action. Samples of pure PJ were collected from 16 patients with stabilized external pancreatic fistulas. The antimicrobial activity of the juice at different concentrations (from 1.25 to 100%) alone and in combination with mezlocillin, imipenem, ceftriaxone, gentamicin, ofloxacin, and ciprofloxacin was studied by a microbiological method (continuous turbidimetric recording of bacterial growth). The human PJ showed dose-dependent antimicrobial activity that increased directly with the concentration. The activity of the antibiotics at bactericidal concentrations were not modified by the PJ, while the combination with subinhibitory concentrations produced the following variable and different effects: (i) additivity with mezlocillin, ceftriaxone, gentamicin, and ciprofloxacin and autonomy (no interaction) with imipenem and ofloxacin against Providencia rettgeri and (ii) additivity with ceftriaxone, ofloxacin, gentamicin, imipenem, and mezlocillin and autonomy with ciprofloxacin against Escherichia coli. In the presence of PJ, fluoroquinolones showed constant positive effects, while beta-lactams showed more variable antimicrobial activity. Antibiotic concentrations and PJ pharmacodynamics are the main factors determining the final effect of the interaction in vitro. These results may be useful in choosing antibiotics for the treatment of pancreatic infections when they are supplemented with the pharmacokinetic data for each drug.

Penetration of ciprofloxacin into the human pancreas

The aim of this study was to determine the concentrations of ciprofloxacin in human pancreatic tissue and juice. Concentrations were measured by high-pressure liquid chromatography (HPLC). Two hundred mg of ciprofloxacin were administered as a short i.v. infusion (30 min). The median ciprofloxacin concentrations 140 min (median) after the start of infusion in pancreatic tissue as well as in pancreatic juice were 0.9 mg/kg (mg/l). The penetration ratio was 1.0 for pancreatic tissue and 0.83 for pancreatic juice. With regard to the minimal inhibitory concentrations (MIC) for the respective bacteria, ciprofloxacin seems to be an appropriate drug for the treatment of septic complications in necrotizing pancreatitis. Future clinical trials are necessary to prove this assumption.

Antimicrobial treatment of pancreatic infection in cats

An investigation examined the efficacy of antibiotics in a novel feline model of pancreatic infection in acute pancreatitis. Acute pancreatitis was induced in cats using an established technique. In control animals (no pancreatitis) and cats with pancreatitis, Escherichia coli (10(4) in 0.1 ml) was placed in the pancreatic duct. Reoperation was performed after 24 h in six controls and six cats with pancreatitis. E. coli was cultured from the pancreas in five control animals and five cats with pancreatitis. Reoperation was performed after 1 week in ten controls, in 11 cats with pancreatitis and in nine with pancreatitis that were treated with cefotaxime (50 mg/kg intramuscularly three times daily) started 12 h after the induction of pancreatitis and administration of E. coli. Pancreatic infection developed in eight cats with pancreatitis compared with none of the cefotaxime-treated animals and none of the controls (P < 0.05). Cefotaxime reached bactericidal levels in pancreatic tissue and juice. In conclusion, ductal administration of E. coli caused pancreatic infection only in cats with acute pancreatitis. Early administration of an appropriate antibiotic was effective in treating pancreatic infection in acute pancreatitis.

Behavior of antibiotics during human necrotizing pancreatitis

The aim of the study was to verify whether antibiotics excreted by the normal pancreas are also excreted in human necrotizing pancreatitis, reaching the tissue sites of the infection. Twelve patients suffering from acute necrotizing pancreatitis were treated with imipenem-cilastatin (0.5 g), mezlocillin (2 g), gentamicin (0.08 g), amikacin (0.5 g), pefloxacin (0.4 g), and metronidazole (0.5 g). Serum and necrotic samples were collected simultaneously at different time intervals after parenteral drug administration by computed tomography-guided needle aspiration, intraoperatively, and from surgical drainages placed during surgery. Drug concentrations were determined by microbiological and high-performance liquid chromatography assays. All antibiotics reached the necrotic tissues, but with varying degrees of penetration, this being low for aminoglycosides (13%) and high in the case of pefloxacin (89%) and metronidazole (99%). The concentrations of pefloxacin (13.0 to 23 micrograms/g) and metronidazole (8.4 micrograms/g) in the necrotic samples were distinctly higher than the MICs for the organisms most commonly isolated in this disease; the concentrations in tissue of imipenem (3.35 micrograms/g) and mezlocillin (8.0 and 15.0 micrograms/g) did not always exceed the MICs for 90% of strains tested, whereas the aminoglycoside concentrations in necrotic tissue (0.5 microgram/g) were inadequate. Repeated administration of drugs (for 3, 7, 17, and 20 days) seems to enhance penetration of pefloxacin, imipenem, and metronidazole into necrotic pancreatic tissue. The choice of antibiotics in preventing infected necrosis during necrotizing pancreatitis should be based on their antimicrobial activity, penetration rate, persistence, and therapeutic concentrations in the necrotic pancreatic area. These requisites are provided by pefloxacin and metronidazole and to a variable extent by imipenem and mezlocillin.

Penetration of ceftazidime into human pancreas

The use of antibiotics in patients with severe acute pancreatitis (stage II and III) is indicated since bacterial complications are the most common cause of death in these patients. In the present study the penetration of ceftazidime into pancreatic juice, into healthy and chronically inflamed pancreatic tissue as well as into necrotic regions in cases of severe acute pancreatitis was investigated. A peak concentration of 12.9 +/- 5.9 mg/l was found 60 min after intravenous administration of 35 mg/kg of the drug, which is 32% of the corresponding serum levels. Pancreatic tissue concentrations varied between 9 and 79% of the corresponding serum levels, depending on the stage of inflammation. After five days of antibiotic treatment with doses of 2 g t.i.d., concentrations between 1.8 and 6.9 mg/kg were detected even in pancreatic necroses. This suggests that sufficient antibacterial levels of ceftazidime were present in all pancreatic compartments analyzed following administration of common therapeutic dosages. Therefore, from a pharmacokinetic point of view, ceftazidime could be a potentially effective drug for the treatment of pancreatitis.

Timing of intervention in acute pancreatitis

This review examines the appropriate timing of intervention in acute pancreatitis. In gallstone pancreatitis, it is now clear that cholecystectomy during the primary admission carries no greater risk of complications than delayed cholecystectomy and enables earlier recovery to normal activity. This course of action pre-empts a second, possibly fatal attack of acute pancreatitis. Cholecystectomy should be done after the acute phase has settled, before discharge from hospital. Patients with gallstones should now be offered endoscopic sphincterotomy within 48 hours of admission. This approach is safe, and reduces the risk of complications. When complications develop, early necrosectomy is only indicated if conservative measures fail. Delayed (> 10 days) necrosectomy is appropriate if there is evidence of sepsis, or clinical failure to improve. Pancreatic pseudocysts can often be managed expectantly; a high proportion will resolve spontaneously. After a delay of 12 weeks, persistent cysts require evaluation by endoscopic pancreatography, which gives crucial information in the choice between percutaneous or surgical drainage of the pseudocyst. A patient with pancreatitis is usually treated under the care of a surgeon, who has traditionally taken the decision on the timing of any intervention, and has performed such intervention at open operation. Recently, the development of alternative techniques has enabled the surgeon to call on the skills of his colleagues in endoscopy and interventional radiology. However, the availability of these alternatives to surgery should not affect the timing of intervention unless it can be clearly shown that such a change in timing combined with the minimally invasive technique can improve the outcome for the patient. Intervention may be required to deal with gallstones in the gallbladder or in the bile duct, to deal with, or ideally prevent, the deleterious systemic effects of pancreatic and peripancreatic necrosis, or to drain a peripancreatic abscess. Peripancreatic fluid collections and pancreatic pseudocysts may also require either internal or external drainage to relieve symptoms or prevent complications.

Prospective comparison of C-reactive protein level, Ranson score and contrast-enhanced computed tomography in the prediction of septic complications of acute pancreatitis

Randomized clinical trials of antibiotic prophylaxis in acute pancreatitis are now warranted in the light of recent evidence of pancreatic penetration of certain antibiotics at therapeutic minimal inhibitory concentrations. The aim of the present prospective clinical study was to investigate whether there are detectable risk factors for pancreatic sepsis in acute pancreatitis that would allow better selection of patients for inclusion in clinical trials. Fifty-nine consecutive patients with acute pancreatitis were recruited and submitted to admission baseline and 48-h determinations of Ranson score, and assay of C-reactive protein at admission and weekly intervals thereafter. Contrast-enhanced computed tomography (CT) was also performed within 24 h of admission. Pancreatic sepsis, defined as infection of pancreatic and/or peripancreatic collections, was demonstrated in all cases by culture of samples obtained by needle aspiration and at laparotomy. Although all prognostic indices correlated significantly with sepsis, multivariate logistic regression analysis showed that the only variables predictive of the risk of subsequent sepsis were the presence and extent of necrosis. Early detection of pancreatic necrosis by CT should be the primary inclusion criterion in future clinical trials of antibiotic prophylaxis in acute pancreatitis.

Pancreatic infection complicating acute pancreatitis

Pancreatic infection is the leading cause of death from acute pancreatitis. Patients with severe necrotizing pancreatitis are most at risk. Early computed tomography and percutaneous fine-needle aspiration microbiology of areas of pancreatic necrosis enable early diagnosis. Pancreatic infection should be treated surgically, although sterile necrosis may be managed conservatively. The role of antimicrobial drugs is uncertain.

Human pancreatic tissue concentration of bactericidal antibiotics

Pancreatic infection represents the most important cause of fatal outcome in human acute pancreatitis. In a comparative analysis, human pancreatic tissue concentrations of 10 different bactericidal antibiotics were determined in 89 patients undergoing pancreatic surgery. Concentrations of the antibiotics were determined in the blood and pancreatic tissue using high-pressure liquid chromatography. Pancreatic tissue concentrations 120 minutes after intravenous administration were as follows: mezlocillin, 19.0 mg/kg; piperacillin, 20.3 mg/kg; cefotaxime, 9.1 mg/kg; ceftizoxime, 7.9 mg/kg; netilmicin, 0.4 mg/kg; tobramycin, 0.4 mg/kg; ofloxacin, 1.7 mg/kg; ciprofloxacin, 0.9 mg/kg; imipenem, 6.0 mg/kg; metronidazole, 3.5 mg/kg. Three groups of antibiotics were established: group A, substances with low tissue concentrations (netilmicin, tobramycin), which were below the minimal inhibitory concentrations of most bacteria found in pancreatic infection; group B, antibiotics with pancreatic tissue concentrations which were sufficient to inhibit some but not all bacteria in pancreatic infection (mezlocillin, piperacillin, ceftizoxime, cefotaxime); group C, substances with high pancreatic tissue levels as well as high bactericidal activity against most of the germs present in pancreatic infection (ciprofloxacin, ofloxacin, imipenem). These data could serve as the basis for adequate antibiotic prophylaxis or treatment of pancreatic infection.