Multimodal management - of value in fulminant acute pancreatitis?

Acute lung injury and ARDS in acute pancreatitis: Mechanisms and potential intervention

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) in acute pancreatitis still represents a substantial problem, with a mortality rate in the range of 30%-40%. The present review evaluates underlying pathophysiological mechanisms in both ALI and ARDS and potential clinical implications. Several mediators and pathophysiological pathways are involved during the different phases of ALI and ARDS. The initial exudative phase is characterized by diffuse alveolar damage, microvascular injury and influx of inflammatory cells. This phase is followed by a fibro-proliferative phase with lung repair, type II pneumocyte hypoplasia and proliferation of fibroblasts. Proteases derived from polymorphonuclear neutrophils, various pro-inflammatory mediators, and phospholipases are all involved, among others. Contributing factors that promote pancreatitis-associated ALI may be found in the gut and mesenteric lymphatics. There is a lack of complete understanding of the underlying mechanisms, and by improving our knowledge, novel tools for prevention and intervention may be developed, thus contributing to improved outcome.

Effect of severe acute pancreatitis on pharmacokinetics of Da-Cheng-Qi Decoction components

AIM: To investigate the effect of severe acute pancreatitis (SAP) on pharmacokinetics of Da-Cheng-Qi Decoction (DCQD) components in rats.

METHODS: Rats were divided into SAP group and sham-operation group as a control group (n = 6). Rhein, chrysophanol, rheochrysidin, magnolol, hesperidin and naringin in DCQD were quantified in rat serum by high performance liquid chromatography tandem mass spectrometry for studying their pharmacokinetics.

RESULTS: Early absorption of each DCQD component was tended to degrade in SAP group after treatment with DCQD by gavage. The C_max (chrysophanol, P = 0.0059; rheochrysidin, P = 0.0288; magnolol, P = 0.0487; hesperidin, P = 0.0277; naringin, P = 0.0023) and AUC (rhein, P = 0.0186; chrysophanol, P = 0.0013; magnolol, P = 0.001; hesperidin, P = 0.0081; naringin, P = 0.0272) of DCQD component were obviously lower in SAP group than in control group. The T_1/2α of chrysophanol and rheochrysidin (P = 0.0467 and 0.0005, respectively) and T_max of chrysophanol and rheochrysidin (P = 0.0101 and 0.0037, respectively) lasted longer in SAP group than in control group.

CONCLUSION: SAP can significantly impact the absorption of DCQD components in rats and their pharmacokinetic parameters.

Activation of nuclear factor-κB and intervention of NBD peptides in rats with severe acute pancreatitis

AIM: To study the role of nuclear factor-kappa B (NF-κB) and reactive oxygen species (ROS) in rats with severe acute pancreatitis (SAP), and to evaluate the effect of NF-κB essential modifier binding domain (NBD) peptides on this model.

METHODS: Sodium taurocholate (50 g/L, 1 mL/kg body weight) was retrogradely injected into rats' biliopancreatic ducts to induce the SAP model. Sixty-four rats were randomly divided into 4 groups: sham operation group, SAP group, TAT-NBD (WT) peptides group and TAT-NBD (MT) peptides group. The drugs were intraperitoneally injected into the rats 30 minutes before the operation. The changes of NF-κB P65 protein in pancreas, pancreatic histopathology, serum amylase, and malondialdehyde (MDA), total-superoxide dismutase (T-SOD) in pancreas were evaluated 6 and 12 h after operation.

RESULTS: In comparison with that in the sham operation group, the expression of NF-κB p65 protein was significantly enhanced in the SAP group at 6 or 12 h (49.3 ± 2.2 vs 4.3 ± 1.4, 65.8 ± 1.8 vs 5.0 ± 1.3, both P < 0.05); the production of MDA was also increased (212.7 ± 12.5 vs 87.7 ± 7.5, 296.8 ± 13.3 vs 96.2 ± 8.3, both P < 0.05); however, the activity of T-SOD was lowered (88 ± 10 vs 183 ± 10, 65 ± 7 vs 194 ± 10, both P < 0.05). In comparison with that in the SAP group, the expression of NF-κB p65 protein (25.9 ± 2.3, 38.9 ± 2.6) or the production of MDA (102.5 ± 10.4, 164.5 ± 12.2) was markedly decreased in the TAT-NBD (WT) group, while the activity of T-SOD was notably increased (153 ± 11, 168 ± 12) (P < 0.05); the histological scores for pancreas were also reduced (5.04 ± 0.41 vs 8.71 ± 0.45, 5.45 ± 0.34 vs 10.31 ± 1.23, both P < 0.05); the level of serum amylase had no obvious change. The above indexes had no marked changes in the TAT-NBD (MT) group.

CONCLUSION: NF-κB is over-activated and the production of ROS increases in SAP rats. NBD peptides could selectively inhibit the activation of NF-kappa B, the production of ROS, and thus lessen the inflammatory inury during SAP.

Immunomodulation in surgical practice

BACKGROUND

Immunomodulation may represent a potential way to improve surgical outcome. These types of interventions should be based on detailed knowledge of the underlying mechanisms involved. The aim of the present review is to summarize some experience on the acute phase response, potential ways of intervention and experiences from critical illness and HPB disease.

DISCUSSION

Mechanisms of the acute phase response are discussed including the individual parameters and local changes that take part. Mechanisms involved in failure of the gut barrier are presented and include changes in gut barrier permeability, effects on gut-associated immunocompetent cells, and systemic implications. As examples of HPB disease, mechanisms of the acute phase response and potential ways of intervention in obstructive jaundice and acute pancreatitis are discussed. Nutritional pharmacology and lessons learned from immunomodulation and immunonutrition in critical illness and major abdominal surgery, including upper GI and HPB surgery, are referred to. Overall, immunomodulation represents a potential tool to improve results but requires a thorough mapping of underlying mechanisms in order to achieve individualized treatment or prevention based on patients' specific needs.

Effects of N-acetylcysteine on acute necrotizing pancreatitis in rats

The aim of this study was to investigate the influence of N-acetylcysteine (NAC) on acute necrotizing pancreatitis (ANP) induced by glycodeoxycholic acid in rats. The induction of ANP resulted in significant increase in mortality rate, pancreatic necrosis and serum activity of amylase, alanine aspartate transferase (ALT), interleukin-6 (IL-6), lactate dehydrogenase (LDH) in bronchoalveolar lavage (BAL) fluid, serum concentration of urea, tissue activity of myeloperoxidase (MPO) and malondialdehyde (MDA) in the pancreas and lung, and significant decrease of concentrations of calcium, blood pressure, urine output and pO(2). The use of NAC inhibited the changes in urine output, pO(2), tissue activity of MPO and MDA in pancreas and lungs, and the serum activity of IL-6, ALT, and serum concentrations of urea and calcium. NAC reduced the mortality and pancreatic damage. The use of NAC has a beneficial effect on the course of ANP in rats. It may be used in the treatment of acute pancreatitis.

Potential role of reactive oxygen species in pancreatitis-associated multiple organ dysfunction

BACKGROUND

Severe acute pancreatitis is still associated with substantial morbidity and mortality. Experimental and clinical studies have demonstrated that reactive oxygen species (ROS) represent early occurring inflammatory mediators contributing to cell dysfunction, both locally in the pancreas and remote organs.

METHOD

A systematic literature review was conducted to investigate the potential roles of intra- and intercellular, as well as interorgan signaling of ROS in the development of pancreatitis-associated multiple organ dysfunction syndrome (MODS). A text word search of the Medline, PubMed and Cochrane databases, and a manual search of the citations from these references, was performed.

RESULTS

ROS directly compromise cellular damage and regulate intercellular signals in pancreatitis-associated MODS. ROS are involved in leukocyte activation, production of cytokines, endothelial barrier dysfunction, and microcirculatory barrier dysfunction in acute pancreatitis. Beside effects on intercellular signaling, ROS also affect intracellular events and activate the transcription factor nuclear factor kappa B that regulates inflammatory cytokine expression.

CONCLUSION

ROS is a critical factor responsible for the development of pancreatitis-induced remote organ dysfunction via intercellular and interorgan signaling. The role of antioxidant treatment, included as a part of multimodal management, remains to be investigated.