Pancreatitis

The most common symptoms of pancreatitis are severe upper abdominal or left upper quadrant burning pain radiating to the back, nausea, and vomiting that is worse with eating. The physical examination will vary depending on severity and presence of internal bleeding. Blood pressure may be elevated by pain or decreased by dehydration or bleeding. Heart and respiratory rates are often elevated. The abdomen is usually tender but to a lesser degree than the pain itself. As is common in abdominal disease, bowel sounds may be reduced from reflex bowel paralysis. Fever or jaundice may be present. Chronic pancreatitis can lead to diabetes or pancreatic cancer. Unexplained weight loss may occur from a lack of pancreatic enzymes hindering digestion. Complications Early complications include shock, infection, systemic inflammatory response syndrome, low blood calcium, high blood glucose, and dehydration. Blood loss, dehydration, and fluid leaking into the abdominal cavity (ascites) can lead to kidney failure. Respiratory complications are often severe. Pleural effusion is usually present. Shallow breathing from pain can lead to lung collapse. Pancreatic enzymes may attack the lungs, causing inflammation. Severe inflammation can lead to intra-abdominal hypertension and abdominal compartment syndrome, further impairing renal and respiratory function and potentially requiring management with an open abdomen to relieve the pressure. Late complications include recurrent pancreatitis and the development of pancreatic pseudocysts—collections of pancreatic secretions that have been walled off by scar tissue. These may cause pain, become infected, rupture and bleed, block the bile duct and cause jaundice, or migrate around the abdomen. Acute necrotizing pancreatitis can lead to a pancreatic abscess, a collection of pus caused by necrosis, liquefaction, and infection. This happens in approximately 3% of cases or almost 60% of cases involving more than two pseudocysts and gas in the pancreas. ==Causes==

About 80 percent of pancreatitis cases are caused by gallstones or alcohol. Choledocholithiasis (gallstones in the bile duct) are the single most common cause of acute pancreatitis, and alcoholism is the single most common cause of chronic pancreatitis. Serum triglyceride levels greater than 1000 mg/dL (11.29 mmol/L, i.e., hyperlipidemia) is another cause. The mnemonic "GET SMASHED" is often used to help clinicians and medical students remember the common causes of pancreatitis: Gallstones, Ethanol, Trauma, Steroids, Mumps, Autoimmune, Scorpion sting, Hyperlipidemia, hypothermia or hyperparathyroidism, ERCP, Drugs (commonly azathioprine, valproic acid, liraglutide). Various oral hypoglycemic agents are associated with pancreatitis including metformin, but glucagon-like peptide-1 mimetics such as exenatide are more strongly associated with pancreatitis by promoting inflammation in combination with a high-fat diet. Atypical antipsychotics such as clozapine, risperidone, and olanzapine can also cause pancreatitis. Infection A number of infectious agents have been recognized as causes of pancreatitis including: • Viruses • Coxsackie virus • Cytomegalovirus • Hepatitis B • Herpes simplex virus • Mumps • Varicella-zoster virus • Bacteria • Legionella • Leptospira • Mycoplasma • Salmonella • Fungi • Aspergillus • Parasites • Ascaris • Cryptosporidium • Toxoplasma Other Other common causes include trauma, autoimmune disease, high blood calcium, hypothermia, and endoscopic retrograde cholangiopancreatography (ERCP). Pancreas divisum is a common congenital malformation of the pancreas that may underlie some recurrent cases. Diabetes mellitus type 2 is associated with a 2.8-fold higher risk. Less common causes include pancreatic cancer, pancreatic duct stones, vasculitis (inflammation of the small blood vessels in the pancreas), and porphyria—particularly acute intermittent porphyria and erythropoietic protoporphyria. There is an inherited form that results in the activation of trypsinogen within the pancreas, leading to autodigestion. Involved genes may include trypsin 1, which codes for trypsinogen, SPINK1, which codes for a trypsin inhibitor, or cystic fibrosis transmembrane conductance regulator. ==Diagnosis==

The differential diagnosis for pancreatitis includes but is not limited to cholecystitis, choledocholithiasis, perforated peptic ulcer, bowel infarction, small bowel obstruction, hepatitis, and mesenteric ischemia. Diagnosis requires 2 of the 3 following criteria: • Characteristic acute onset of epigastric or vague abdominal pain that may radiate to the back (see signs and symptoms above) • Serum amylase or lipase levels ≥ 3 times the upper limit of normal • An imaging study with characteristic changes. CT, MRI, abdominal ultrasound, or endoscopic ultrasound can be used for diagnosis. Amylase and lipase are 2 enzymes produced by the pancreas. Elevations in lipase are generally considered a better indicator for pancreatitis as it has greater specificity and a longer half-life. For imaging, abdominal ultrasound is convenient, simple, non-invasive, and inexpensive. It is more sensitive and specific for pancreatitis from gallstones than other imaging modalities. However, in 25–35% of patients the view of the pancreas can be obstructed by bowel gas making it difficult to evaluate. ERCP or an endoscopic ultrasound can also be used if a biliary cause for pancreatitis is suspected. ==Treatment==

The treatment for acute pancreatitis will depend on whether the diagnosis is mild pancreatitis, which typically resolves without treatment, or the severe form, which can cause serious complications. Patients with mild AP should still be hospitalized, at least briefly, to receive IV fluids and clinical monitoring. While the mildest cases of pancreatitis may be managed exclusively with NSAIDs (which are preferred in such scenarios due to the anti-inflammatory effects and the better safety profile), most patients with pancreatitis require heavy opioid regimens for pain therapy. Severe cases often require continuous IV infusions of opioid medications. It is appropriate for emergent cases of pancreatitis to be treated with these medications immediately, rather than attempting to control the pain with lesser medications first. Fluid resuscitation Regardless of disease severity, moderately aggressive fluid resuscitation is advisable for all patients with acute pancreatitis, especially if they can be diagnosed and treated early in the course of the disease. The preferred fluid for administration is lactated Ringer solution, but saline may also be used. Patients with acute pancreatitis of any severity are typically hypovolemic (decreased blood volume), and this hypovolemia can result in hypoperfusion of pancreatic cells. Without an adequate blood supply, pancreatic cells can become necrotic, resulting in tissue death, which can be further worsened by the strong inflammatory response that occurs following necrosis. Mild acute pancreatitis The treatment of mild acute pancreatitis is admission to a general hospital ward for fluid resuscitation and patient monitoring. Opioids may be used for pain. When the pancreatitis is due to gallstones, or even for patients without gallstones and no other identifiable cause, early gallbladder removal also appears to improve outcomes. Severe acute pancreatitis Severe pancreatitis can cause organ failure, necrosis, infected necrosis, pseudocyst, and abscess. If diagnosed with severe acute pancreatitis, people will need to be admitted to a high-dependency unit or intensive care unit. The levels of fluids inside the body will likely have dropped significantly as it diverts bodily fluids and nutrients to repair the pancreas. A drop in fluid levels can lead to a rapid and severe reduction in blood volume, which is known as hypovolemic shock. This condition represents a major life threat and may be prevented in some cases by prompt and aggressive fluid resuscitation. The systemic inflammatory response may inflame the lungs and manifest as acute respiratory distress syndrome (ARDS). As with mild pancreatitis, it will be necessary to treat the underlying cause—gallstones, discontinuing medications, cessation of alcohol, etc. If the cause is gallstones, an ERCP procedure or removal of the gallbladder will likely be recommended. There is also evidence that, even for patients without gallstones, surgical removal of the gallbladder may reduce the risk of recurrence. As of 2024, guidelines recommend the procedure for any patient with severe pancreatitis with no clear cause. Patients whose pancreatitis can be linked to alcoholism are known to have a much higher risk of recurrence. ==Prognosis==

Severe acute pancreatitis has mortality rates around 2–9%, higher where necrosis of the pancreas has occurred. Several scoring systems are used to predict the severity of pancreatitis. They each combine demographic and laboratory data to estimate severity or probability of death. Examples include APACHE II, Ranson, BISAP, and Glasgow. The Modified Glasgow criteria suggests that a case be considered severe if at least three of the following are true: • Age > 55 years • Blood levels: • PO2 oxygen 15,000/μL • Calcium 16 mmol/L • Lactate dehydrogenase (LDH) > 600iu/L • Aspartate transaminase (AST) > 200iu/L • Albumin 10 mmol/L This can be remembered using the mnemonic PANCREAS: • PO2 oxygen 55 • Neutrophilia white blood cells > 15,000/μL • Calcium 16 mmol/L • Enzymes lactate dehydrogenase (LDH) > 600iu/L aspartate transaminase (AST) > 200iu/L • Albumin 10 mmol/L The BISAP score (blood urea nitrogen level >25 mg/dL (8.9 mmol/L), impaired mental status, systemic inflammatory response syndrome, age over 60 years, pleural effusion) has been validated as similar to other prognostic scoring systems. ==Epidemiology==

Globally, the incidence of acute pancreatitis is 5 to 35 cases per 100,000 people. The incidence of chronic pancreatitis is 4–8 per 100,000, with a prevalence of 26–42 cases per 100,000. In 2013 pancreatitis resulted in 123,000 deaths up from 83,000 deaths in 1990. ==Costs==

In adults in the United Kingdom, the estimated average total direct and indirect costs from chronic pancreatitis is roughly £79,000 per person annually. Acute recurrent pancreatitis and chronic pancreatitis occur infrequently in children, but are associated with high healthcare costs due to substantial disease burden. ==Other animals==

Fatty foods may cause canine pancreatitis in dogs. == See also ==