Major pathological mechanisms of acute pancreatitis are prevented by N-acetylcysteine

Research Progress of Antioxidant Nanomaterials for Acute Pancreatitis

Acute pancreatitis (AP) is a complex inflammatory disease caused by multiple etiologies, the pathogenesis of which has not been fully elucidated. Oxidative stress is important for the regulation of inflammation-related signaling pathways, the recruitment of inflammatory cells, the release of inflammatory factors, and other processes, and plays a key role in the occurrence and development of AP. In recent years, antioxidant therapy that suppresses oxidative stress by scavenging reactive oxygen species has become a research highlight of AP. However, traditional antioxidant drugs have problems such as poor drug stability and low delivery efficiency, which limit their clinical translation and applications. Nanomaterials bring a brand-new opportunity for the antioxidant treatment of AP. This review focuses on the multiple advantages of nanomaterials, including small size, good stability, high permeability, and long retention effect, which can be used not only as effective carriers of traditional antioxidant drugs but also directly as antioxidants. In this review, after first discussing the association between oxidative stress and AP, we focused on summarizing the literature related to antioxidant nanomaterials for the treatment of AP and highlighting the effects of these nanomaterials on the indicators related to oxidative stress in pathological states, aiming to provide references for follow-up research and promote clinical application.

Systematic Review of Calcium Channels and Intracellular Calcium Signaling: Relevance to Pesticide Neurotoxicity

Pesticides of different chemical classes exert their toxic effects on the nervous system by acting on the different regulatory mechanisms of calcium (Ca2+) homeostasis. Pesticides have been shown to alter Ca2+ homeostasis, mainly by increasing its intracellular concentration above physiological levels. The pesticide-induced Ca2+ overload occurs through two main mechanisms: the entry of Ca2+ from the extracellular medium through the different types of Ca2+ channels present in the plasma membrane or its release into the cytoplasm from intracellular stocks, mainly from the endoplasmic reticulum. It has also been observed that intracellular increases in the Ca2+ concentrations are maintained over time, because pesticides inhibit the enzymes involved in reducing its levels. Thus, the alteration of Ca2+ levels can lead to the activation of various signaling pathways that generate oxidative stress, neuroinflammation and, finally, neuronal death. In this review, we also discuss some proposed strategies to counteract the detrimental effects of pesticides on Ca2+ homeostasis.

N-Acetylcysteine Reduces the Pro-Oxidant and Inflammatory Responses during Pancreatitis and Pancreas Tumorigenesis

Pancreatitis, an inflammation of the pancreas, appears to be a main driver of pancreatic cancer when combined with Kras mutations. In this context, the exact redox mechanisms are not clearly elucidated. Herein, we treated mice expressing a Kras^G12D mutation in pancreatic acinar cells with cerulein to induce acute pancreatitis. In the presence of Kras^G12D, pancreatitis triggered significantly greater redox unbalance and oxidative damages compared to control mice expressing wild-type Kras alleles. Further analyses identified the disruption in glutathione metabolism as the main redox event occurring during pancreatitis. Compared to the wild-type background, Kras^G12D-bearing mice showed a greater responsiveness to treatment with a thiol-containing compound, N-acetylcysteine (NAC). Notably, NAC treatment increased the pancreatic glutathione pool, reduced systemic markers related to pancreatic and liver damages, limited the extent of pancreatic edema and fibrosis as well as reduced systemic and pancreatic oxidative damages. The protective effects of NAC were, at least, partly due to a decrease in the production of tumor necrosis factor-α (TNF-α) by acinar cells, which was concomitant with the inhibition of NF-κB(p65) nuclear translocation. Our data provide a rationale to use thiol-containing compounds as an adjuvant therapy to alleviate the severity of inflammation during pancreatitis and pancreatic tumorigenesis.

Influence of daily oral prophylactic selenium treatment on the dibutyltin dichloride (DBTC)-induced pancreatitis in rats

Dibutyltin dichloride (DBTC) is an organotin compound used as model for acute and chronic pancreatitis. Oxidative stress is one of the mechanisms of propagation of acinar cell injury in acute pancreatitis. Selenium is an essential cofactor in the antioxidant glutathione peroxidase pathway. Selenium levels are described to be subnormal in patients with acute and chronic pancreatitis. The aim of our studies was to determine the prophylactic effect of Na-selenite [5 mg kg^-1 body weight (b.w.) per os (p.o.) 7 days] on the pathogenesis and course of DBTC- induced pancreatitis. Male inbred rats (LEW-1W Charles River) of 150 g body weight were used in this study. Experimental pancreatitis was induced by intravenous administration of 6 mg kg^-1 b.w. DBTC in rats. Na-selenite was administered as daily oral dose of 5 mg kg^-1 b.w. 7 days before induction of DBTC-pancreatitis. Malondialdehyde (MDA) was measured for monitoring levels of oxidative stress. Elimination of DBTC was reflected as tin concentration in bile and urine. Organ changes were indicated by serum parameters as well as histology. A prophylactic Na-selenite application significantly diminished MDA- and bilirubin concentration in serum, activities of lipase and transaminases as well as organ injuries compared to DBTC- treated rats in the absence of Na-selenite. The prophylactic oral treatment with Na-selenite in the scope of DBTC-induced pancreatitis points to a reduced oxidative stress characterized by diminished MDA serum levels and a milder course of pancreatitis suggesting prophylactic substitution with Na-selenite to probably elicit beneficial effect on the clinical outcome in patients with endoscopic retrograde cholangiopancreatography (ERCP).

Experimental and clinical evidence of antioxidant therapy in acute pancreatitis

Oxidative stress has been shown to play an important role in the pathogenesis of acute pancreatitis (AP). Antioxidants, alone or in combination with conventional therapy, should improve oxidative-stress-induced organ damage and therefore accelerate the rate of recovery. In recent years, substantial amounts of data about the efficiency of antioxidants against oxidative damage have been obtained from experiments with rodents. Some of these antioxidants have been found beneficial in the treatment of AP in humans; however, at present there is insufficient clinical data to support the benefits of antioxidants, alone or in combination with conventional therapy, in the management of AP in humans. Conflicting results obtained from experimental animals and humans may represent distinct pathophysiological mechanisms mediating tissue injury in different species. Further detailed studies should be done to clarify the exact mechanisms of tissue injury in human AP. Herein I tried to review the existing experimental and clinical studies on AP in order to determine the efficiency of antioxidants. The use of antioxidant enriched nutrition is a potential direction of clinical research in AP given the lack of clues about the efficiency and safety of antioxidant usage in patients with AP.

Hyperbaric oxygen and N-acetylcysteine treatment in L-arginine-induced acute pancreatitis in rats

BACKGROUND

This study was designed to evaluate the combined effects of hyperbaric oxygen (HBO) and N-acetylcysteine (NAC) on acute necrotizing pancreatitis in rats.

METHODS

Experiments were performed in 50 male Wistar rats, which were divided into five groups (N = 10 for each group). The first group received normal saline (0.9% NaCl) intraperitoneal and served as the control group. In the second group, acute pancreatitis was induced by 3.2-g/kg body weight L-arginine intraperitoneal twice at an interval of 1 hr, which has been shown previously to produce severe necrotizing acute pancreatitis. In the third group, NAC treatment (1000 mg/kg) was given after 1 hr of the induction of acute pancreatitis twice 24 hr apart. In the fourth group, animals received HBO, 6 hr after the induction of pancreatitis twice 12 hr apart. In the fifth group, animals received together NAC as in Group 3 and HBO treatment as in Group 4. Groups 1, 2, and 3 were left under normal atmospheric pressures. Twelve hours after last treatment, the animals were killed by exsanguinations. Blood samples were studied for amylase, calcium, and lactate dehydrogenase (LDH), pancreatic histology, pancreatic tissue malondialdehyde, superoxide dismutase, and glutathione levels.

RESULTS

Acute pancreatitis is reduced by the treatment of NAC, HBO, NAC + HBO. HBO + NAC groups performed statistically the best in preventing L-arginine-induced acute necrotising pancreatitis.

CONCLUSIONS

NAC especially combined with HBO, decreases oxidative stress parameters, serum amylase, calcium, and LDH levels, as well as histopathologic score.

Multidrug strategies are effective in the treatment of severe experimental pancreatitis

BACKGROUND

Trypsinogen activation, oxygen radicals, cytokines, leukocyte infiltration, and pancreatic ischemia are important steps in the pathogenesis of necrotizing pancreatitis and associated systemic complications. Several drugs that inhibit those pathogenetic steps attenuated biochemical and histologic changes, while survival remained low. The aim of the present study was to evaluate the benefit of multidrug approaches compared to monotherapies on organ injury and survival in acute experimental pancreatitis in the rat model of retrograde bile injection combined with intravenous cerulein.

METHODS

Necrotizing pancreatitis was induced in rats. After a therapy-free interval of 6 hours, 10 treatment regimens were evaluated: multidrug regimen 1, which contained the protease inhibitor gabexate mesilate, oxygen-free radical scavengers, nitric oxide donor L-arginine, a platelet-activating factor antagonist, and antibodies against intracellular adhesion molecule-1 (ICAM-1) dissolved in dextran, was compared to multidrug regimen 2 (dextran, acetylcysteine, L-arginine, and anti-ICAM-1), monotherapies of each of the drugs, and standard intravascular volume replacement.

RESULTS

Both multidrug regimens significantly reduced pancreatic and systemic injury and microcirculatory disturbances compared to any of the monotherapies. Treatment with regimen 1 decreased 24-hour mortality to 0% and increased long-term survival to 85% (standard therapy, 70% and 15%, respectively). Multidrug regimen 2 was as effective as regimen 1.

CONCLUSION

Treatment of acute necrotizing pancreatitis with multidrug regimens significantly decreases short-term mortality compared to monotherapies. Moreover, multidrug strategies are still effective after a wide therapeutic window. Key to this effective therapy is the inhibition of microcirculatory disturbances and of the systemic inflammatory response. The experimental superiority of the multidrug approach should be confirmed in a clinical trial.

N-acetylcysteine in acute pancreatitis

Premature trypsinogen activation and production of oxygen free radicals (OFR) are early pathogenic events which occur within acinar cells and trigger acute pancreatitis (AP). OFR exert their harmful effects on various cell components causing lipid peroxidation, disturbances in calcium homeostasis and DNA damage, which lead to increased cell injury and eventually cell death. This review presents the most recent data concerning the effects of N-Acetylcysteine (NAC), in the treatment of AP. NAC is an antioxidant capable of restoring the levels of Glutathione, the most important cellular antioxidant. Studies show the beneficial effects of NAC treatment in preventing OFR production and therefore attenuating oxidative damage. Additionally, NAC treatment has been shown to prevent the increase in cytosolic Ca²⁺ concentration and reduce the accumulation of enzymes in acinar cells during AP. The prevention, by NAC, of these pathological events occurring within acinar would contribute to reducing the severity of AP. NAC is also capable of reducing the activation of transcription factors especially sensitive to the cellular redox state, such as Nuclear factor-κB, signal transducer and activator of transcription-3 and mitogen-activated protein kinase. This leads to a down-regulation of cytokines, adhesion molecules and chemokine expression in various cell types during AP. These findings point to NAC as a powerful therapeutic treatment, attenuating oxidative-stress-induced cell injury and other pathological events at early stages of AP, and potentially contributing to reducion in the severity of disease.

Mechanisms of dexamethasone-mediated chemokine down-regulation in mild and severe acute pancreatitis

This study aimed to investigate the role of therapeutic dexamethasone (Dex) treatment on the mechanisms underlying chemokine expression during mild and severe acute pancreatitis (AP) experimentally induced in rats. Regardless of the AP severity, Dex (1 mg/kg), administered 1 h after AP, reduced the acinar cell activation of extracellular signal-regulated kinase (ERK) and c-Jun-NH(2)-terminal kinase (JNK) but failed to reduce p38-mitogen-activated protein kinase (MAPK) in severe AP. In both AP models, Dex inhibited the activation of nuclear factor-kappaB (NF-kappaB) and signal transducers and activators of transcription (STAT) factors. All of this resulted in pancreatic down-regulation of the chemokines monocyte chemoattractant protein-1 (MCP-1) and cytokine-induced neutrophil chemoattractant (CINC). Lower plasma chemokine levels as well as decreased amylasemia, hematocrit and plasma interleukin-1beta (Il-1beta) levels were found either in mild or severe AP treated with Dex. Pancreatic neutrophil infiltration was attenuated by Dex in mild but not in severe AP. In conclusion, by targeting MAPKs, NF-kappaB and STAT3 pathways, Dex treatment down-regulated the chemokine expression in different cell sources during mild and severe AP, resulting in decreased severity of the disease.

Medical treatment of severe acute pancreatitis with multiple organ dysfunction syndrome

Severe acute pancreatitis (SAP) is one of the crucial acute abdominal diseases. Multiple organ dysfunction syndromes (MODS) is the main cause of death in SAP patients. The medical treatment measures include the fundamental cure such as fluid resuscitation, correction of the internal environment disorder and hyoxemia, and preferred application of somatostatin, adequate use of trypsin inhibitors, antibiotics and early enteral nutrition. In addition, immunomodulation, antioxidants, blood purification and endoscopic interventional therapy may be selective to improve the prognosis of SAP.

Pharmacological approach to acute pancreatitis

The aim of the present review is to summarize the current knowledge regarding pharmacological prevention and treatment of acute pancreatitis (AP) based on experimental animal models and clinical trials. Somatostatin (SS) and octreotide inhibit the exocrine production of pancreatic enzymes and may be useful as prophylaxis against Post Endoscopic retrograde cholangiopancreatography Pancreatitis (PEP). The protease inhibitor Gabexate mesilate (GM) is used routinely as treatment to AP in some countries, but randomized clinical trials and a meta-analysis do not support this practice. Nitroglycerin (NGL) is a nitrogen oxide (NO) donor, which relaxes the sphincter of Oddi. Studies show conflicting results when applied prior to ERCP and a large multicenter randomized study is warranted. Steroids administered as prophylaxis against PEP has been validated without effect in several randomized trials. The non-steroidal anti-inflammatory drugs (NSAID) indomethacin and diclofenac have in randomized studies showed potential as prophylaxis against PEP. Interleukin 10 (IL-10) is a cytokine with anti-inflammatory properties but two trials testing IL-10 as prophylaxis to PEP have returned conflicting results. Antibodies against tumor necrosis factor-alpha (TNF-α) have a potential as rescue therapy but no clinical trials are currently being conducted. The antibiotics beta-lactams and quinolones reduce mortality when necrosis is present in pancreas and may also reduce incidence of infected necrosis. Evidence based pharmacological treatment of AP is limited and studies on the effect of potent anti-inflammatory drugs are warranted.

Treatment with anti-factor VIIa in acute pancreatitis in rats: blocking both coagulation and inflammation?

OBJECTIVE

Acute pancreatitis starts as an autodigestive process restricted to the pancreas and progresses to a systemic inflammation via cytokine release into the blood stream. Several inhibitors of the coagulation cascade, including active-site-inactivated factor VIIa, have shown anti-inflammatory properties in other inflammatory models than acute pancreatitis. Free radical scavengers have proven useful in reducing the oxidative damage during hyperinflammatory conditions. The aim of this study was to investigate whether pretreatment with FVIIai would have any effect on the multiple organ dysfunction syndrome (MODS) in severe acute pancreatitis.

MATERIAL AND METHODS

Experimental acute pancreatitis was induced by intraductal infusion of taurodeoxycholate in the pancreatic duct. The animals were pretreated with N-acetyl-cysteine and active-site-inactivated factor VIIa. Neutrophil infiltration in the lungs, ileum and colon was quantified by myeloperoxidase activity. Inflammatory markers, IL-6 and MIP-2, were measured using ELISA.

RESULTS

Tissue infiltration of neutrophils in the lungs, ileum and colon significantly increased during acute pancreatitis as compared to sham operation. These levels were reduced by pretreatment with N-acetylcysteine and active-site-inactivated factor VIIa. Levels of interleukin-6 and macrophage inflammatory protein-2 increased significantly during acute pancreatitis. Pretreatment with NAC and FVIIai reduced these levels.

CONCLUSIONS

Both N-acetylcysteine and active-site-inactivated factor VIIa showed powerful anti-inflammatory properties in experimental acute pancreatitis. As they exert their effects through different physiological mechanisms, they represent potential candidates for future multimodal treatment of acute pancreatitis.

Relationship between acute pancreatitis and oxidative stress

Under the imbalance between generation of reactive oxygen species and inadequate antioxidant defense systems, oxidative stress can cause cell damage either directly or indirectly through altering signaling pathways. It is the etiopathogenisis and also the consequence of many diseases. Oxidative injury plays an important role not only in the pathogenesis of acute pancreatitis (AP) but also in pancreatitis-induced damages of other organs such as heart, liver, lung, kidney, alimentary canal and so on. Oxidative stress can produce a higher level of reactive oxygen species (ROS) and reactive nitrogen species (RNS), which induce inflammatory reaction and microcirculation disturbance, and cell necrosis or apoptosis, leading to pancreatic inflammation and multiple organ dysfunction syndromes. The antioxidants can decrease the production of oxygen free radicals (or directly scavenge them), protect the antioxidant enzyme activity, reinforce the antioxidative capacity of bodies, and consequently play an obvious therapeutic effect on AP.

Perturbed Synaptosomal Calcium Homeostasis and Behavioral Deficits Following Carbofuran Exposure: Neuroprotection by N-Acetylcysteine

The protective effects of N-acetylcysteine (NAC) on carbofuran-induced alterations in calcium homeostasis and neurobehavioral functions were investigated in rats. Rats were exposed to carbofuran at a dose of 1 mg/kg body weight, orally for a period of 28 days. A significant decrease in Ca2+ATPase activity was observed following carbofuran exposure with a concomitant increase in K+ -induced (45)Ca2+ uptake through voltage operated calcium channels. This was accompanied with a marked accumulation of intracellular free calcium in synaptosomes. The increase in intracellular calcium levels were associated with an increased lipid peroxidation and decreased glutathione content in carbofuran exposed animals. NAC administration (200 mg/kg body weight, orally) to the carbofuran exposed animals had a beneficial effect on carbofuran-induced alterations in calcium homeostasis and resulted in repletion in glutathione levels and resulted in lowering the extent of lipid peroxidation. Marked impairment in the motor functions were seen following carbofuran exposure, which were evident by the significant decrease in the locomotor activity and reduction in the retention time of the rats on rotating rods. Cognitive deficits were also seen as indicated by the significant decrease in active and passive avoidance response. NAC treatment, on the other hand, protected the animals against carbofuran-induced neurobehavioral deficits. The results support the hypothesis that carbofuran exerts its toxic effects by disrupting calcium homeostasis, which may have serious consequences on neuronal functioning, and clearly show the potential beneficial effects of N-acetylcysteine on carbofuran induced alterations in synaptosomal calcium homeostasis.

Influence of selenium treatment on the acute toxicity of dibutyltin dichloride in rats

BACKGROUND/AIMS

Dibutyltin dichloride (DBTC) is an organotin compound used as a model for acute pancreatitis. The aim was to determine the effect of various doses of Na-selenite on the pathogenesis and course of DBTC-induced toxic changes in organs and serum of rats.

METHODS

Experimental pancreatitis was induced by intravenous administration of 6 mg kg(-1) BW DBTC. Na-selenite was applied as a single intravenous dose of 5 mg kg(-1) BW and as daily oral dose of 1 mg kg(-1) BW. Malondialdehyde (MDA) was detected to observe the level of oxidative stress. The tin concentration in bile and urine shows the elimination of DBTC. Organ changes were indicated by serum parameters as well as histology.

RESULTS

DBTC causes an acute pancreatitis, cholestasis and liver lesions determined by specific elevated serum parameters and several histological lesions. Na-selenite significantly diminished MDA concentration, lipase, bilirubin and transaminases as well as organ injuries compared to only DBTC-treated rats.

CONCLUSIONS

The treatment with Na-selenite in the scope of DBTC-induced pancreatitis points to a reduced oxidative stress characterized by diminished MDA serum levels and a milder course of pancreatitis. The generation of DBTC-Na-selenite complexes could also be a mechanism to decrease the toxicity of organotin compounds like DBTC.

Free radicals and the pancreatic acinar cells: role in physiology and pathology

Reactive oxygen and nitrogen species (ROS and RNS) play an important role in signal transduction and cell injury processes. Nitric oxide synthase (NOS)-the key enzyme producing nitric oxide (NO)-is found in neuronal structures, vascular endothelium and, possibly, in acinar and ductal epithelial cells in the pancreas. NO is known to regulate cell homeostasis, and its effects on the acinar cells are reviewed here. ROS are implicated in the early events within the acinar cells, leading to the development of acute pancreatitis. The available data on ROS/RNS involvement in the apoptotic and necrotic death of pancreatic acinar cells will be discussed.

N-acetylcysteine -- passe-partout or much ado about nothing?

In experimental studies, the old mucolytic agent N-acetylcysteine (NAC) has had beneficial effects in disorders supposedly linked to oxidative stress. Numerous, mainly small clinical trials with variable doses have yielded inconsistent results in a wide variety of diseases. NAC added to the conventional therapy of human immunodeficiency virus infection might be of benefit; in respect of chronic obstructive pulmonary disease, systematic reviews and meta-analyses suggested that prolonged treatment with NAC is efficacious, but a recent multicentre study has questioned this. In a large intervention trial on cancer recurrence, NAC was ineffective. NAC infusions have been widely used in acute hepatic failure but convincing evidence of its benefits is lacking. A preliminary study reported that NAC is effective in preventing radiocontrast-induced nephropathy but thereafter highly mixed results have been published, and even meta-analyses disagree on its efficacy. In intensive care NAC has mostly been a disappointment but recently it has 'given promises' in surgery with cardiopulmonary bypass. NAC therapy is routine only in paracetamol intoxication.

Intravenous N-acetylcysteine does not prevent post-ERCP pancreatitis

BACKGROUND

Acute pancreatitis remains the most common complication of ERCP. Prophylactic administration of N-acetylcysteine (NAC) probably decreases the incidence and the severity of experimental pancreatitis. The aim of the present study was to assess the efficacy of intravenous NAC for prevention of post-ERCP pancreatitis in humans, who represent an appropriate model to study the potential role of NAC in this setting.

METHODS

A prospective, double-blind, placebo-controlled trial was conducted in 256 patients who underwent ERCP. Patients were randomized to receive intravenous NAC at a loading dose of 70 mg/kg 2 hours before and 35 mg/kg at 4-hour intervals for a total of 24 hours after the procedure, or to receive normal saline solution as placebo. Patients were clinically evaluated, and serum amylase levels were measured before and 6 hours and 24 hours after the procedure. Standardized criteria were used to diagnose and to grade the severity of post-ERCP pancreatitis.

RESULTS

A total of 249 patients were included in the analysis. The two groups were matched for age, gender, underlying disease and indication for treatment, ERCP findings, and type of treatment. The overall incidence of post-ERCP acute pancreatitis was 10.8%, with 12.1% in the NAC group and 9.6% in the placebo group. There were no statistical differences in the incidence or severity grades between the groups. The mean duration of hospitalization for pancreatitis also was similar in the NAC group and the placebo group (3.6 +/- 0.9 and 3 +/- 1.5 days, respectively).

CONCLUSIONS

The results of this trial show the absence of any beneficial effect of NAC on the incidence and the severity of ERCP-induced pancreatitis.

Actin overexpression parallels severity of pancreatic injury

Among the three major cytofilament proteins, keratin (K8/K18/K19) expression increases nearly threefold upon pancreas or liver injury, while actin and tubulin expressions are considered relatively stable. K8/K18 serves essential hepatocyte cytoprotective functions yet appears dispensable in K8-null mouse pancreata, which led us to hypothesize that actin or tubulin expressions may increase after pancreatic injury. Balb/c and FVB/n mice manifested different susceptibility to injury in two pancreatitis models, with significant induction of actin protein (threefold) and RNA after moderate or severe but not mild injury. Alterations in tubulin expression were less prominent. Basally, K8-null and wild-type pancreata expressed similar actin and tubulin levels, while the injury-induced actin protein but not RNA was more pronounced in K8-null mice. K7/K18/K19/K20 were also induced in K8-null mice after injury. Ex vivo, caerulein-triggered pancreatitis caused protein degradation (actin approximately or = tubulin > keratins) and mRNA up-regulation that was blocked by actinomycin-D (act-D) (actin approximately or = tubulin approximately or = keratin) or by NF-kappaB inhibition (keratins > actin approximately or = tubulin). Hence, actin is not as static as previously held and is overexpressed after moderate to severe pancreatic injury while keratins are induced after minimal injury. Keratin and actin induction may serve protective roles in pancreatic injury.

Hyperamylasaemia and acute pancreatitis in paracetamol poisoning

BACKGROUND

Hyperamylasaemia and even acute pancreatitis have been reported in patients with paracetamol poisoning.

AIMS

To describe the incidence, clinical characteristics, and prognostic implications of hyperamylasaemia in paracetamol poisoning.

PATIENTS

Six hundred and two patients transferred to a specialized unit with severe paracetamol poisoning and 212 unselected patients admitted from the local region.

METHODS

Retrospective study based on hospital charts. The optimum threshold of serum amylase to discriminate non-survivors was identified.

RESULTS

An elevated serum amylase (>100 U/L) occurred in 28 of the unselected patients (13%), in 218 of the transferred patients (36%), and in 118 of 148 patients (80%) with fulminant hepatic failure. Only 33 cases of paracetamol-associated acute pancreatitis were diagnosed. A threshold serum amylase of 150 U/L to discriminate non-survivors had sensitivity 76%, specificity 85%, positive predictive value 33%, and negative predictive value 97%. In a logistic regression analysis, a serum amylase > 150 U/L was associated with an excess mortality (odds ratio 5.0, 2.6-9.7).

CONCLUSIONS

Hyperamylasaemia is frequent in patients with paracetamol poisoning, whereas clinical acute pancreatitis occurs rarely. The incidence of hyperamylasaemia increases with the degree of hepatic dysfunction. A serum amylase exceeding 1.5 times the upper normal limit indicates a poor prognosis.