Acute Pancreatitis

Illustration: Anatomy recall

Pancreatitis, Acute Background: The pancreas is a gland located in the upper, posterior abdomen and is responsible for insulin production (endocrine pancreas)

And the manufacture and secretion of digestive enzymes (exocrine pancreas) leading to: carbohydrate fat and protein metabolism

Pancreatitis, Acute Background: Approximately 80% of the gross weight of the pancreas supports exocrine function, while the remaining 20% is involved with endocrine function

Pancreatitis Background: As mentioned, the principal function of the exocrine pancreas is to make food-digesting enzymes The pancreas, comprising only 0.1% of total body weight

Pancreatitis Background: Enzymes are produced within the pancreatic acinar cells packaged into storage vesicles called zymogens and then released via the pancreatic ductal cells and intercalate ducts into the pancreatic duct where they are secreted into the small intestine to begin the metabolic process

Pancreatitis, Acute Background: When a meal is ingested, the: vagal nerves VIP GRP secretin and CCK stimulate enzymatic release into the pancreatic duct

Background: The pro-enzymes travel to the brush border of the duodenum, where trypsinogen, the pro-enzyme for trypsin, is activated

Background: A feedback mechanism exists to limit pancreatic enzyme activation after appropriate metabolism has occurred

It is hypothesized that elevated levels of trypsin, having become unbound from digesting food, lead to: decreased CCK and secretin levels ► thus limiting further pancreatic secretion

Background: Because premature activation of pancreatic enzymes within the pancreas leads to: organ injury and pancreatitis several mechanisms exist to limit this occurrence

Background: ► (1) First, proteins are translated into the inactive proenzymes

►(2) Zymogen granules have: an acidic pH and a low calcium concentration which are factors that guard against premature activation of pancreatic enzymes

Background: Under various conditions, these protective mechanisms are disrupted resulting: 1) in intracellular enzyme activation and 2) pancreatic autodigestion leading to pancreatitis

Pancreatitis, Acute Definition Is a common nonbacterial inflammatory disease caused by *activation, *interstitial liberation, and *autodigestion of the pancreas Remember This process may or not be accompanied by permanent:

* morphologic and * functional changes in the gland

Pancreatitis Definition Acute pancreatitis Is characterized by:

* sudden upper abdominal pain * nausea * vomiting and * elevated serum amylase

Pancreatitis Definition Chronic pancreatitis Is characterized by:

* chronic pain * pancreatic calcification on X-ray, and * exocrine (steatorrhea) or * endocrine (diabetes mellitus) insufficiency

Pancreatitis Definition Acute relapsing pancreatitis Is defined as multiple attacks of pancreatitis without permanent pancreatic scarring, a most often associated with biliary pancreatitis

Pancreatitis Definition Subacute pancreatitis Has also been used by some to describe the minor acute attacks that typically appear late in alcoholic pancreatitis

Pancreatitis Etiology Most cases of pancreatitis are causes by: * gallstone disease or * alcoholism

A) Biliary pancreatitis About 40% of cases of acute pancreatitis are associated with gallstone disease which, if untreated, usually gives rise to additional acute attacks

Pancreatitis Etiology B) Alcoholic pancreatitis In the USA, alcoholism accounts for about 40% of cases of pancreatitis Characteristically, the patients have been heavy users of:

* hard liquor or * wine

Etiology C) Hypercalcemia * hyperthyroidism and * other disorder accompanied by hypercalcemia are occasionally complicated by acute pancreatitis▼ Note:

►hypercalcemia may prematurely activated proteases ►they may also facilitate calculous precipitation in the ducts

Pancreatitis Etiology D) Hyperlipidemia In some patients especially alcoholic, hyperlipidemia appears transiently during acute attack of pancreatitis E) Familial Pancreatitis In this condition, attack of abdominal pain usually begin in childhood

Pancreatitis Etiology F) Protein deficiency In certain populations where dietary protein intake is markedly deficient, ►the incidence of chronic pancreatitis is high

G) Postoperative (Iatrogenic) pancreatitis

Pancreatitis Etiology H) Drug-induced pancreatitis Drugs are probably responsible for more cases of acute pancreatitis than is generally suspected ►The most commonly: corticosteroids contraceptives diuretics and tetracyclines

I)

Idiopathic pancreatitis and miscellaneous causes

Pathogenesis The following are the most popular theories that attempt to link the known etiology factors with autodigestion

► Obstructive secretion ► Common Channel Theory if the bile is mixed with bacteria if the bile salts are deconjugated ► bile is rendered more harmful)

► Duodenal Reflux (after bilroth II gastrectomy)

Pancreatitis Pathogenesis ► It must be admitted that a satisfactory explanation of the pathogenesis of pancreatitis is not presently available ► In biliary pancreatitis, transient obstruction of the ampulla of vater by a gallstone is most likely the first event

Pancreatitis Pathogenesis Alcoholic pancreatitis probably has several causes, including: ► partial ductal obstruction ► secretory stimulation and ► chronic toxic actions of alcohol on parenchymal cells

Pancreatitis Pathogenesis Once a cellular injury pattern has been initiated, macrophages release cytokines that further mediate local inflammatory responses

The early mediators defined to date are: * tumor necrosis factor-alpha * interleukin-6 and * interleukin-8

Pancreatitis Pathogenesis These mediators of inflammation cause an increased pancreatic vascular permeability, leading to: hemorrhage edema and eventually pancreatic necrosis

Background: systemic complications can arise, such as: 1) bacteremia due to gut flora translocation 2) acute respiratory distress syndrome 3) pleural effusions 4) gastrointestinal hemorrhage and 5) renal failure

Background: The systemic inflammatory response syndrome can also develop, leading to the development of systemic shock Eventually, the mediators of inflammation can become so overwhelming to the body that: * hemodynamic instability and * death ensue

Pancreatitis, Acute Frequency: Internationally In the US: In 2002, 230,000 patients with acute pancreatitis were admitted to nonfederally funded hospitals In Luneburg, Germany, the frequency is 17.5 cases per 100,000 people In Finland, the frequency is 73.4 cases per 100,000 people

Pancreatitis, Acute

Frequency: Internationally In India Bengal and Tamyl Nadou 55% has alcohol related pancreatitis

Pancreatitis, Acute Mortality/Morbidity: The overall mortality rate of patients with acute pancreatitis is 10-15%

In patients with severe disease (necrosis and/or organ failure), the mortality rate is approximately 30%

Pancreatitis, Acute Sex: In general, acute pancreatitis affects males more often than females ► The etiology in males is more often related to alcohol in females, to biliary tract disease

Age: The median age at onset depends on the etiology

Clinical Presentation History: The cardinal symptom of acute pancreatitis is abdominal pain Which is characteristically ▼ dull, boring and steady

Usually the pain is: sudden onset and gradually intensifies in severity until reaching a constant ache

Clinical Presentation History: The acute attack frequently begins following a large meal Most often it located in the upper upper abdomen, usually in the epigastrium region ► But it may be perceived more on the left or right side, depending on which portion of the pancreas is involved

Clinical Presentation History: ► The pain radiated directly through the abdomen to the back in approximaltely one half of cases

► Nausea and vomiting are often present along with accompanying anorexia

► Diarrhea can also occur

Clinical Presentation History: Positioning can be important, because the discomfort frequently improves with the patient in the supine position The duration of pain varies but typically lasts more than a day

It is the intensity and persistence of the pain that usually causes patients to seek medical attention

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