Intraperitoneal free fatty acids induce severe hypocalcemia in rats: a model for the hypocalcemia of pancreatitis

Gut microbiota interacts with inflammatory responses in acute pancreatitis

Acute pancreatitis (AP) is one of the most common acute abdominal conditions, and its incidence has been increasing for years. Approximately 15-20% of patients develop severe AP (SAP), which is complicated by critical inflammatory injury and intestinal dysfunction. AP-associated inflammation can lead to the gut barrier and function damage, causing dysbacteriosis and facilitating intestinal microbiota migration. Pancreatic exocrine deficiency and decreased levels of antimicrobial peptides in AP can also lead to abnormal growth of intestinal bacteria. Meanwhile, intestinal microbiota migration influences the pancreatic microenvironment and affects the severity of AP, which, in turn, exacerbates the systemic inflammatory response. Thus, the interaction between the gut microbiota (GM) and the inflammatory response may be a key pathogenic feature of SAP. Treating either of these factors or breaking their interaction may offer some benefits for SAP treatment. In this review, we discuss the mechanisms of interaction of the GM and inflammation in AP and factors that can deteriorate or even cure both, including some traditional Chinese medicine treatments, to provide new methods for studying AP pathogenesis and developing therapies.

New insights into the etiology, risk factors, and pathogenesis of pancreatitis in dogs: Potential impacts on clinical practice

While most cases of pancreatitis in dogs are thought to be idiopathic, potential risk factors are identified. In this article we provide a state‐of‐the‐art overview of suspected risk factors for pancreatitis in dogs, allowing for improved awareness and detection of potential dog‐specific risk factors, which might guide the development of disease prevention strategies. Additionally, we review important advances in our understanding of the pathophysiology of pancreatitis and potential areas for therapeutic manipulation based thereof. The outcome of pathophysiologic mechanisms and the development of clinical disease is dependent on the balance between stressors and protective mechanisms, which can be evaluated using the critical threshold theory.

Hypocalcemia in COVID-19: Prevalence, clinical significance and therapeutic implications

COVID-19 extra-pulmonary features include several endocrine manifestations and these are becoming strongly clinically relevant in patients affected influencing disease severity and outcomes.At the beginning of COVID-19 pandemic no population data on calcium levels in patients affected were available and in April 2020 a first case of severe acute hypocalcemia in an Italian patient with SARS-CoV-2 infection was reported. Subsequently, several studies reported hypocalcemia as a highly prevalent biochemical abnormality in COVID-19 patients with a marked negative influence on disease severity, biochemical inflammation and thrombotic markers, and mortality. Also a high prevalence of vertebral fractures with worse respiratory impairment in patients affected and a widespread vitamin D deficiency have been frequently observed, suggesting an emerging "Osteo-Metabolic Phenotype" in COVID-19.To date, several potential pathophysiological factors have been hypothesized to play a role in determining hypocalcemia in COVID-19 including calcium dependent viral mechanisms of action, high prevalence of hypovitaminosis D in general population, chronic and acute malnutrition during critical illness and high levels of unbound and unsaturated fatty acids in inflammatory responses.Since hypocalcemia is a frequent biochemical finding in hospitalized COVID-19 patients possibly predicting worse outcomes and leading to acute cardiovascular and neurological complications if severe, it is reasonable to assess, monitor and, if indicated, replace calcium at first patient hospital evaluation and during hospitalization.

Contributing Factors for Calcium Changes During Hospitalization in COVID-19: A Longitudinal Study

BACKGROUND

Hypocalcemia is highly prevalent in Coronavirus disease 2019 (COVID-19). There is limited evidence about the course and roles of different parameters in the occurrence of new or worsening hypocalcemia.

OBJECTIVES

This prospective longitudinal study was conducted on hospitalized COVID-19 patients in Qazvin, Iran, in 2021.

METHODS

Serum levels of calcium, albumin, parathormone (PTH), 25(OH)D (vitamin D), magnesium, and phosphate were assessed on the first day (time one), as well as fourth to sixth days (time two) of hospitalization. Paired t-test, McNemar's test, and multivariate logistic regression test were used to compare data at two times and evaluating the independent roles of different variables in the occurrence or worsening of hypocalcemia.

RESULTS

Out of a total of 123 participants, 102 patients completed the study. The mean serum calcium level significantly decreased from 8.32 ± 0.52 mg/dL to 8.02 ± 0.55 mg/dL at time two compared to time one (P < 0.001). Also, we witnessed new or worsening hypocalcemia at time two in 44 (55%) patients with normal serum calcium or mild hypocalcemia at time one (P < 0.001). The PTH level decreased from 42.17 ± 27.20 pg/mL to 31.28 ± 23.42 pg/mL (P < 0.001). The decrease in albumin and PTH levels was an independent significant factor in the occurrence or worsening of hypocalcemia at time two (OR = 1.27; 95% CI: 1.10 - 1.46; P = 0.001 for each 1 g/L decrement in albumin and OR = 1.29; 95% CI: 1.03 - 1.62; P = 0.026 for each 10 pg/mL decrement in PTH). Vitamin D deficiency or changes during hospitalization did not have a significant role in new or worsening hypocalcemia.

CONCLUSIONS

Decreased PTH secretion and hypoalbuminemia have significant roles in the occurrence of new or worsening hypocalcemia during hospitalization due to COVID-19.

Therapeutic plasma exchange for hyperlipidemic pancreatitis: Current evidence and unmet needs

With changes in lifestyle and diet worldwide, the prevalence of hyperlipidemic acute pancreatitis (HLAP) has greatly increased, and it has become the most common cause of acute pancreatitis not due to gallstones or alcohol. There are many available therapies for HLAP, including oral lipid-lowering agents, intravenous insulin, heparin, and therapeutic plasmapheresis (TPE). It is believed that the risk and severity of HLAP increase with rising levels of serum triglycerides (TG), thus a rapid decrease in serum TG level is the key to the successful management of HLAP. TPE has emerged as an effective modality in rapidly reducing serum TG levels. However, due to its cost and accessibility, TPE remains poorly evaluated until now. Some studies revealed its efficacy in helping to treat and prevent the recurrence, while some studies suggested that TG levels were not correlated with disease severity, mortality, or length of hospital stay. Thus TPE might have no beneficial effect for the outcome. This article gives an overview of the published evidence of TPE in the treatment of HLAP and outlines current evidence regarding individual outcome predictors, adverse effects of the procedure, and TPE in special occasions such as for pregnant patients and patients with diabetic ketoacidosis. Future direction of TPE research for HLAP is also discussed in this review.

Pancreatic triglyceride lipase mediates lipotoxic systemic inflammation

Visceral adipose tissue plays a critical role in numerous diseases. Although imaging studies often show adipose involvement in abdominal diseases, their outcomes may vary from being a mild self-limited illness to one with systemic inflammation and organ failure. We therefore compared the pattern of visceral adipose injury during acute pancreatitis and acute diverticulitis to determine its role in organ failure. Acute pancreatitis-associated adipose tissue had ongoing lipolysis in the absence of adipocyte triglyceride lipase (ATGL). Pancreatic lipase injected into mouse visceral adipose tissue hydrolyzed adipose triglyceride and generated excess nonesterified fatty acids (NEFAs), which caused organ failure in the absence of acute pancreatitis. Pancreatic triglyceride lipase (PNLIP) increased in adipose tissue during pancreatitis and entered adipocytes by multiple mechanisms, hydrolyzing adipose triglyceride and generating excess NEFAs. During pancreatitis, obese PNLIP-knockout mice, unlike obese adipocyte-specific ATGL knockouts, had lower visceral adipose tissue lipolysis, milder inflammation, less severe organ failure, and improved survival. PNLIP-knockout mice, unlike ATGL knockouts, were protected from adipocyte-induced pancreatic acinar injury without affecting NEFA signaling or acute pancreatitis induction. Therefore, during pancreatitis, unlike diverticulitis, PNLIP leaking into visceral adipose tissue can cause excessive visceral adipose tissue lipolysis independently of adipocyte-autonomous ATGL, and thereby worsen organ failure.

Thyroidectomy induces thyroglobulin formation by parotid salivary glands in rats

Structural changes in parotid gland (PG) were previously reported following ablation of thyroid gland. However, the functional alterations (especially for proteins) have not been elucidated yet. Herein, we investigated the effect of rat thyroidectomy on PG structure and protein content and studied the ability of thyroxin-supplementation to alleviate the associated structural and functional changes. Male young adult 4-month old albino rats (n = 48) were allocated equally into 4 groups (control, sham-operated, thyroidectomized, and thyroxin-supplemented). PGs were examined histologically, and their proteins expression and localization were analyzed using western blot (WB) and immunohistochemistry (IHC), respectively at 3 w and 5 w post-surgery. Functionally, PGs of thyroidectomized rats formed a newly expressed 300 KDa protein, which was confirmed to be thyroglobulin (TG) by WB and IHC, with higher expression at 5 w. TG was localized in the interstitium, within capillaries, in the cytoplasm of the intralobular ductal cells, in the secretory products within the ductal lumen, and in the cytoplasm of individual small cells at the periphery of the acini. This functional change accompanied by structural changes in PGs (presence of dark and light acinar cells, TG-like colloid material, and high periductal vasculature). Noteworthy, PG of the thyroxin-supplemented depicted vanishment of TG. From these data, it could be concluded that thyroidectomy could alter the morphology and function of the parotid that induce a thyroid-like reprogramming of the parotid to secrete TG and thyroxin supplementation could alleviate this effect.

Obesity Expands a Distinct Population of T Cells in Adipose Tissue and Increases Vulnerability to Infection

Obesity in humans is associated with poorer health outcomes after infections compared with non-obese individuals. Here, we examined the effects of white adipose tissue and obesity on T cell responses to viral infection in mice. We show that lymphocytic choriomeningitis virus (LCMV) grows to high titer in adipose tissue. Virus-specific T cells enter the adipose tissue to resolve infection but then remain as a memory population distinct from memory T cells in lymphoid tissues. Memory T cells in adipose tissue are abundant in lean mice, and diet-induced obesity further increases memory T cell number in adipose tissue and spleen. Upon re-challenge infection, memory T cells rapidly cause severe pathogenesis, leading to increases in lipase levels, calcification of adipose tissue, pancreatitis, and reduced survival in obese mice but not lean mice. Thus, obesity leads to a unique form of viral pathogenesis involving memory T cell-dependent adipocyte destruction and damage to other tissues.

Obesity is associated with increased morbidity and mortality after viral infections. Using a mouse model of obesity, Misumi et al. identify a distinct population of memory T cells in white adipose tissue and a memory cell-dependent pathogenic response to infection that leads to acute fat necrosis, pancreatitis, and lethality.

Ringer's Lactate Prevents Early Organ Failure by Providing Extracellular Calcium

OBJECTIVE

Ringer's lactate may improve early systemic inflammation during critical illnesses like severe acute pancreatitis, which are associated with hypocalcemia. Ringer's lactate is buffered and contains lactate and calcium. We, thus analyzed extracellular calcium or lactate's effects on the mechanisms, intermediary markers, and organ failure in models mimicking human disease with nonesterified fatty acid (NEFA) elevation.

METHODS

Meta-analyses and experimental studies were performed. Experimentally, extracellular calcium and lactate were compared in their interaction with linoleic acid (LA; a NEFA increased in human severe pancreatitis), and its subsequent effects on mitochondrial depolarization and cytosolic calcium signaling resulting in cell injury. In vivo, the effect of LA was studied on organ failure, along with the effect of calcium or lactate (pH 7.4) on severe acute pancreatitis-associated organ failure. A meta-analysis of human randomized control trials comparing Ringer's lactate to normal saline was done, focusing on necrosis and organ failure.

RESULTS

Calcium reacted ionically with LA and reduced lipotoxic necrosis. In vivo, LA induced organ failure and hypocalcemia. During severe pancreatitis, calcium supplementation in saline pH 7.4, unlike lactate, prevented hypocalcemia, increased NEFA saponification, reduced circulating NEFA and C-reactive protein , reduced pancreatic necrosis adjacent to fat necrosis, and normalized shock (carotid pulse distension) and blood urea nitrogen elevation on day 1. This, however, did not prevent the later increase in serum NEFA which caused delayed organ failure. Meta-analysis showed Ringer's lactate reduced necrosis, but not organ failure, compared with normal saline.

CONCLUSION

Hypocalcemia occurs due to excess NEFA binding calcium during a critical illness. Ringer's lactate's early benefits in systemic inflammation are by the calcium it provides reacting ionically with NEFA. This, however, does not prevent later organ failure from sustained NEFA generation. Future studies comparing calcium supplemented saline resuscitation to Ringer's lactate may provide insights to this pathophysiology.

Multimodal Transgastric Local Pancreatic Hypothermia Reduces Severity of Acute Pancreatitis in Rats and Increases Survival

BACKGROUND & AIMS

Acute pancreatitis (AP) of different etiologies is associated with the activation of different signaling pathways in pancreatic cells, posing challenges to the development of targeted therapies. We investigated whether local pancreatic hypothermia, without systemic hypothermia, could lessen the severity of AP induced by different methods in rats.

METHODS

A urethane balloon with 2 polyurethane tubes was placed inside the stomach of rats. AP was induced in Wistar rats by the administration of cerulein or glyceryl tri-linoleate (GTL). Then, cold water was infused into the balloon to cool the pancreas. Pancreatic temperatures were selected based on those found to decrease acinar cell injury. An un-perfused balloon was used as a control. Pancreatic and rectal temperatures were monitored, and an infrared lamp or heating pad was used to avoid generalized hypothermia. We collected blood, pancreas, kidney, and lung tissues and analyzed them by histology, immunofluorescence, immunoblot, cytokine and chemokine magnetic bead, and DNA damage assays. The effect of hypothermia on signaling pathways initiated by cerulein and GTL was studied in acinar cells.

RESULTS

Rats with pancreatic cooling developed less severe GTL-induced AP compared with rats that received the control balloon. In acinar cells, cooling decreased the lipolysis induced by GTL, increased the micellar form of its fatty acid, lowered the increase in cytosolic calcium, prevented the loss of mitochondrial membrane potential (by 70%-80%), and resulted in a 40%-50% decrease in the uptake of a fatty acid tracer. In rats with AP, cooling decreased pancreatic necrosis by 48%, decreased serum levels of cytokines and markers of cell damage, and decreased markers of lung and renal damage. Pancreatic cooling increased the proportions of rats surviving 6 hours after induction of AP (to 90%, from <10% of rats that received the control balloon). In rats with cerulein-induced AP, pancreatic cooling decreased pancreatic markers of apoptosis and inflammation.

CONCLUSIONS

In rats with AP, transgastric local pancreatic hypothermia decreases pancreatic necrosis, apoptosis, inflammation, and markers of pancreatitis severity and increases survival.

A Retrospective Research of the Characteristic of Hypertriglyceridemic Pancreatitis in Beijing, China

Aim. To investigate the characteristic of hypertriglyceridemic- (HTG-) induced pancreatitis (HTG pancreatitis). Methods. We reviewed 126 cases of HTG pancreatitis and 168 cases of biliary pancreatitis as control. Results. The HTG group mean age was younger than biliary group. The number of females was a little higher than males in both groups. There were 18 cases that were recurrent in HTG group and 11 in billiary group. The mean hospitalization times were 13.7 ± 2.6 and 11.2 ± 2.3 days in two groups. Six patients received apheresis in HTG group. The proportion of severe AP was 31.0% and 26.2%, mortality 1.6% and 1.2%, comorbidity of diabetes mellitus (DM) 20.6% and 6.5% in two groups. The number of complications of gastrointestinal (GI) bleeding, sepsis, and multiple organ dysfunction syndrome (MODS) in HTG group and biliary group was 1, 1, and 2 versus 4, 12, and 4. Conclusions. The proportion of recurrent and severe AP and comorbidity of DM of HTG group was higher than billiary group. The proportion of the complications of GI bleeding, sepsis, and MODS of HTG group was less than biliary group. Apheresis could effectively reduce serum TG levels soon. There was no significant difference of the mortality between two groups.

Peripancreatic fat necrosis worsens acute pancreatitis independent of pancreatic necrosis via unsaturated fatty acids increased in human pancreatic necrosis collections

BACKGROUND AND AIMS

Peripancreatic fat necrosis occurs frequently in necrotising pancreatitis. Distinguishing markers from mediators of severe acute pancreatitis (SAP) is important since targeting mediators may improve outcomes. We evaluated potential agents in human pancreatic necrotic collections (NCs), pseudocysts (PCs) and pancreatic cystic neoplasms and used pancreatic acini, peripheral blood mononuclear cells (PBMC) and an acute pancreatitis (AP) model to determine SAP mediators.

METHODS

We measured acinar and PBMC injury induced by agents increased in NCs and PCs. Outcomes of caerulein pancreatitis were studied in lean rats coadministered interleukin (IL)-1β and keratinocyte chemoattractant/growth-regulated oncogene, triolein alone or with the lipase inhibitor orlistat.

RESULTS

NCs had higher fatty acids, IL-8 and IL-1β versus other fluids. Lipolysis of unsaturated triglyceride and resulting unsaturated fatty acids (UFA) oleic and linoleic acids induced necro-apoptosis at less than half the concentration in NCs but other agents did not do so at more than two times these concentrations. Cytokine coadministration resulted in higher pancreatic and lung inflammation than caerulein alone, but only triolein coadministration caused peripancreatic fat stranding, higher cytokines, UFAs, multisystem organ failure (MSOF) and mortality in 97% animals, which were prevented by orlistat.

CONCLUSIONS

UFAs, IL-1β and IL-8 are elevated in NCs. However, UFAs generated via peripancreatic fat lipolysis causes worse inflammation and MSOF, converting mild AP to SAP.

Lipolysis of visceral adipocyte triglyceride by pancreatic lipases converts mild acute pancreatitis to severe pancreatitis independent of necrosis and inflammation

Visceral fat necrosis has been associated with severe acute pancreatitis (SAP) for over 100 years; however, its pathogenesis and role in SAP outcomes are poorly understood. Based on recent work suggesting that pancreatic fat lipolysis plays an important role in SAP, we evaluated the role of pancreatic lipases in SAP-associated visceral fat necrosis, the inflammatory response, local injury, and outcomes of acute pancreatitis (AP). For this, cerulein pancreatitis was induced in lean and obese mice, alone or with the lipase inhibitor orlistat and parameters of AP induction (serum amylase and lipase), fat necrosis, pancreatic necrosis, and multisystem organ failure, and inflammatory response were assessed. Pancreatic lipases were measured in fat necrosis and were overexpressed in 3T3-L1 cells. We noted obesity to convert mild cerulein AP to SAP with greater cytokines, unsaturated fatty acids (UFAs), and multisystem organ failure, and 100% mortality without affecting AP induction or pancreatic necrosis. Increased pancreatic lipase amounts and activity were noted in the extensive visceral fat necrosis of dying obese mice. Lipase inhibition reduced fat necrosis, UFAs, organ failure, and mortality but not the parameters of AP induction. Pancreatic lipase expression increased lipolysis in 3T3-L1 cells. We conclude that UFAs generated via lipolysis of visceral fat by pancreatic lipases convert mild AP to SAP independent of pancreatic necrosis and the inflammatory response.

Acute lipotoxicity regulates severity of biliary acute pancreatitis without affecting its initiation

Obese patients have worse outcomes during acute pancreatitis (AP). Previous animal models of AP have found worse outcomes in obese rodents who may have a baseline proinflammatory state. Our aim was to study the role of acute lipolytic generation of fatty acids on local severity and systemic complications of AP. Human postpancreatitis necrotic collections were analyzed for unsaturated fatty acids (UFAs) and saturated fatty acids. A model of biliary AP was designed to replicate the human variables by intraductal injection of the triglyceride glyceryl trilinoleate alone or with the chemically distinct lipase inhibitors orlistat or cetilistat. Parameters of AP etiology and outcomes of local and systemic severity were measured. Patients with postpancreatitis necrotic collections were obese, and 13 of 15 had biliary AP. Postpancreatitis necrotic collections were enriched in UFAs. Intraductal glyceryl trilinoleate with or without the lipase inhibitors resulted in oil red O-positive areas, resembling intrapancreatic fat. Both lipase inhibitors reduced the glyceryl trilinoleate-induced increase in serum lipase, UFAs, pancreatic necrosis, serum inflammatory markers, systemic injury, and mortality but not serum alanine aminotransferase, bilirubin, or amylase. We conclude that UFAs are enriched in human necrotic collections and acute UFA generation via lipolysis worsens pancreatic necrosis, systemic inflammation, and injury associated with severe AP. Inhibition of lipolysis reduces UFA generation and improves these outcomes of AP without interfering with its induction.

Potential influence of intravenous lipids on the outcomes of acute pancreatitis

Parenteral nutrition (PN) has been associated with a higher rate of adverse outcomes compared with enteral feeding in patients with acute pancreatitis (AP). However, PN may be necessary when feeding via the enteral route is poorly tolerated or impossible, and PN is recommended as a second-line nutrition therapy in AP. Intravenous (IV) lipids are commonly used as a part of PN in patients with AP. While the adverse outcomes related to the use of PN in AP have commonly been attributed to infectious complications, data suggest that the unsaturated fatty acids in the triglycerides used in IV lipids may contribute to the development of organ failure. We discuss the clinical and experimental data on this issue and the alternative lipid emulsions that are being studied.

Issues in hypertriglyceridemic pancreatitis: an update

Hypertriglyceridemia (HTG) is a well-established but underestimated cause of acute pancreatitis and recurrent acute pancreatitis. The clinical presentation of HTG-induced pancreatitis (HTG pancreatitis) is similar to other causes. Pancreatitis secondary to HTG is typically seen in the presence of one or more secondary factors (uncontrolled diabetes, alcoholism, medications, pregnancy) in a patient with an underlying common genetic abnormality of lipoprotein metabolism (familial combined hyperlipidemia or familial HTG). Less commonly, a patient with rare genetic abnormality (familial chylomicronemic syndrome) with or without an additional secondary factor is encountered. The risk of acute pancreatitis in patients with serum triglycerides >1000 and >2000 mg/dL is ∼ 5% and 10% to 20%, respectively. It is not clear whether HTG pancreatitis is more severe than when it is due to other causes. Clinical management of HTG pancreatitis is similar to that of other causes. Insulin infusion in diabetic patients with HTG can rapidly reduce triglyceride (TG) levels. Use of apheresis is still experimental and better designed studies are needed to clarify its role in the management of HTG pancreatitis. Diet, lifestyle changes, and control of secondary factors are key to the treatment, and medications are useful adjuncts to the long-term management of TG levels. Control of TG levels to 500 mg/dL or less can effectively prevent recurrences of pancreatitis.

Differences in the inflammatory response induced by acute pancreatitis in different white adipose tissue sites in the rat

BACKGROUND

There is increasing evidence of the role of adipose tissue on the systemic effects of acute pancreatitis. Patients with higher body mass index have increased risk of local and systemic complications and patients with android fat distribution and higher waist circumference are at greater risk for developing the severe form of the disease. Here we evaluated the changes on different areas of adipose tissue and its involvement on the inflammatory response in an experimental model of acute pancreatitis.

METHODS

Pancreatitis was induced in male Wistar rats by intraductal administration of sodium taurocholate. Orlistat was administered to inhibit lipase activity. Activation of peritoneal macrophages was evaluated by measuring IL1β and TNFα expression. Inflammation was evaluated by measuring myeloperoxidase activity in mesenteric, epididymal and retroperitoneal areas of adipose tissue. Changes in the expression of inflammatory mediator in these areas of adipose tissue were also evaluated by RT-PCR.

RESULTS

Pancreatitis induces the activation of peritoneal macrophages and a strong inflammatory response in mesenteric and epididymal sites of adipose tissue. By contrast, no changes were found in retroperitoneal adipose tissue. Inhibition of lipase prevented the activation of macrophages and the local inflammation in adipose tissue.

CONCLUSIONS

Our results confirm the involvement of adipose tissue on the progression of systemic inflammatory response during acute pancreatitis. However, there is a considerable diversity in different adipose tissue sites. These differences need to be taken into account in order to understand the progression from local pancreatic damage to systemic inflammation during acute pancreatitis.

Lipotoxicity causes multisystem organ failure and exacerbates acute pancreatitis in obesity

Obesity increases the risk of adverse outcomes during acute critical illnesses such as burns, severe trauma, and acute pancreatitis. Although individuals with more body fat and higher serum cytokines and lipase are more likely to experience problems, the roles that these characteristics play are not clear. We used severe acute pancreatitis as a representative disease to investigate the effects of obesity on local organ function and systemic processes. In obese humans, we found that an increase in the volume of intrapancreatic adipocytes was associated with more extensive pancreatic necrosis during acute pancreatitis and that acute pancreatitis was associated with multisystem organ failure in obese individuals. In vitro studies of pancreatic acinar cells showed that unsaturated fatty acids were proinflammatory, releasing intracellular calcium, inhibiting mitochondrial complexes I and V, and causing necrosis. Saturated fatty acids had no such effects. Inhibition of lipolysis in obese (ob/ob) mice with induced pancreatitis prevented a rise in serum unsaturated fatty acids and prevented renal injury, lung injury, systemic inflammation, hypocalcemia, reduced pancreatic necrosis, and mortality. Thus, therapeutic approaches that target unsaturated fatty acid-mediated lipotoxicity may reduce adverse outcomes in obese patients with critical illnesses such as severe acute pancreatitis.

[Water and electrolyte disturbances in critical care]

Management of critically ill patients regularly involves the treatment of water and electrolyte disturbances. Moreover, critical care itself may contribute to volume overload and electrolyte abnormalities. Initial therapy should be followed by consequent diagnostic evaluation. The shift of volume and potassium in severe pancreatitis, for example, may lead to a life-threatening situation. In brain-dead patients, successful organ donation is facilitated by careful maintenance of water and electrolyte homeostasis.

Hypocalcemia in patients with acute pancreatitis: a putative role for systemic endotoxin exposure

INTRODUCTION

Hypocalcemia is not uncommon during acute pancreatitis and is associated with a poor outcome. Whilst the mechanisms responsible for its development remain unclear, there is evidence to implicate endotoxemia in other models of sepsis.

AIM

To investigate the potential role of systemic endotoxin exposure in the development of hypocalcemia in patients with acute pancreatitis.

METHODOLOGY

Adjusted serum calcium was measured daily, and the lowest value within 72 hours of admission for acute pancreatitis was determined. Serum endotoxin and both IgG and IgM antiendotoxin core antibodies (EndoCAbs) were measured on admission. Attacks were classified as mild (n = 51) or severe (n = 21) according to the criteria of the Atlanta International Symposium of 1992.

RESULTS

Hypocalcemia was significantly more frequent (86% versus 39%, p < 0.001) and reached significantly lower levels during severe attacks than during mild attacks (median [interquartile range], 2.06 [1.78-2.17] mmol/L, versus 2.23 [2.15-2.30] mmol/L; p < 0.001). Endotoxemia was present in a significantly greater proportion of patients with severe disease (71% versus 41%; p = 0.037), and serum IgM and IgG EndoCAbs were significantly depleted during severe attacks in comparison with mild attacks (p = 0.007 and p = 0.039, respectively). A negative and significant correlation was observed between endotoxemia and both the admission and lowest serum concentrations of adjusted calcium (r = -0.424 and p = 0.022; r = -0.383 and p = 0.037, respectively), and the latter correlated significantly with serum IgG EndoCAb concentrations (r = 0.251; p = 0.036).

CONCLUSION

Systemic endotoxin exposure appears to play a significant role in the development of hypocalcemia in patients with acute pancreatitis.

Fluid and electrolyte abnormalities

Patients with cancer are at risk for developing a variety of fluid and electrolyte disturbances caused by the disease process or by complications from therapy. An understanding of the pathophysiology of these potential abnormalities allows the clinician to manage patients expectantly and to avoid severe metabolic disarray by correcting imbalances promptly.

Hypocalcemia during porcine endotoxemic shock: effects of calcium administration

OBJECTIVE

To evaluate the pathophysiology involved in hypocalcemia in septic shock and to investigate the value of calcium administration.

DESIGN

Prospective, randomized placebo-controlled trial with parallel groups.

SETTING

Animal research laboratory at the University Hospital of Uppsala.

SUBJECTS

Twenty-four pigs aged 12-14 wks receiving general anesthesia.

INTERVENTIONS

Twenty pigs received endotoxin infusion (10 microg/kg/hr) for 6 hrs. Ten of these pigs also received a calcium infusion (20 mmol total) in parallel. Four control pigs received only saline.

MEASUREMENTS AND MAIN RESULTS

At the end of the study, blood ionized calcium (Ca2+) had declined from 1.32+/-0.04 mmol/L (mean +/- SD) to 1.09+/-0.06 mmol/L in pigs receiving endotoxin (p < .05 vs. controls) compared with 1.38+/-0.04 mmol/L to 1.25+/-0.07 mmol/L in controls and 1.39+/-0.03 mmol/L to 1.24+/-0.07 mmol/L in endotoxemic pigs receiving calcium. In both endotoxemic groups, total calcium levels in ascites were increased by 56% (p < .005 vs. controls), and an accumulation of calcium in the liver was mainly seen in the endotoxemic group receiving calcium (p < .008 vs. controls). Total Ca2+ levels in adiposal tissue and skeletal muscle were similar in all groups. Calcium administration did not significantly alter systemic hemodynamics or survival in this model of septic shock (four survivors in the endotoxemic group and five in the calcium administration group).

CONCLUSIONS

Endotoxemia in the pig rapidly induced hypocalcemia. Calcium accumulation was found in ascites and in the liver, but not in other examined tissues. Calcium administration, restoring the Ca2+ concentration, did not improve hemodynamics or survival in this model of hypodynamic sepsis. Porcine endotoxemic shock, which replicates human septic shock, seems to be suitable for evaluating calcium turnover.

Parathyroid hormone and ionized calcium levels are related to the severity of illness and survival in critically ill patients

BACKGROUND

The present study explores serum parathyroid hormone (PTH) and blood ionized calcium (Ca2+) levels in relation to the severity of disease and mortality in the intensive care unit (ICU).

METHODS

In a pilot study, 37 consecutive critically ill patients admitted to the ICU were studied with determinations of serum PTH and total serum calcium within the first 24 h. In a following prospective study, patients suffering from sepsis (n = 13) or subjected to major surgery (n = 13) were investigated daily for 1 week with determinations of serum PTH and ionized calcium (Ca2+). Severity of disease was assessed by the APACHE II score and hospital mortality was recorded.

RESULTS

In the pilot study, serum PTH levels were elevated (> 55 ng L-1) in 38% of the patients and were not related to serum calcium but showed a significant relationship to the APACHE II score (r = 0.39, P < 0.05). In the prospective study, serum PTH was elevated in 69% of the patients in both groups at inclusion, and 6 days later 87% of the septic and 37% of the surgery patients still showed elevated levels. Hypocalcaemia was more commonly seen in the septic patients [mean Ca2+ 1.03 +/- 0.08 (SD) mmol L-1] than in the surgical patients (1.14 +/- 0.06 mmol L-1) at inclusion. Both PTH and Ca2+ levels were significantly related to the APACHE II score (r = 0.46, P < 0.03, and r = -0.54, P < 0.009, respectively). Furthermore, PTH levels were significantly increased in non-survivors (n = 5) compared with survivors (mean 161 +/- 51 vs. 79 +/- 51 ng L-1, P < 0.005).

CONCLUSION

Hypocalcaemia and increased levels of PTH were common findings in critically ill patients. These alterations in calcium homeostasis were related to the severity of disease and increased PTH levels were associated with a poor outcome.