Acute Pancreatitis | Acute Pancreatitis made easy

 Acute Pancreatitis. if you want to understand the topic of acute pancreatitis, then this is best place for you. Because we teach medicine for preparation of exams. we will teach you core concepts of acute pancreatitis...!

What is Acute pancreatitis?

Acute pancreatitis is a condition where the pancreas gets inflammed(swollen)  in short period of time.

Pancreas is an organ which secretes different metabolic enzymes and chemicals which help in digestion.

Causes:

• Idiopathic, 
• Gallstones, 
• Ethanol, 
• Trauma, 
• Steroids, 
• Mumps, 
• Autoimmune disease, 
•  Scorpion sting, 
• Hypercalcemia/Hypertriglyceridemia (> 1000 mg/dL), 
• ERCP, 
• Drugs (eg, sulfa drugs, NRTIs, protease inhibitors)

Clinical Features:

• Fever, tachycardia, hypotension
• Dyspnea, tachypnea &/or basilar crackles
• Abdominal tenderness &/or distension
• Cullen sign: periumbilical bluish coloration indicating hemoperitoneum
• Grey Turner sign: reddish-brown coloration around flanks indicating retroperitoneal bleed

Diagnosis (requires 2 of the follow)

• Acute epigastric pain radiating to the back
• Amylase or lipase >3 times normal limit
• Abnormalities on imaging consistent with
  pancreatitis

Other findings

• ALT level >150 U/L suggests gallstone pancreatitis
• Severe disease: fever, tachypnea, hypoxemia, hypotension

Associated with ↑ risk of severe pancreatitis:

• Age >75
• Obesity
• Alcoholism
• C-reactive protein >150 mg/dL at 48 hr after presentation
• Rising blood urea nitrogen & creatinine in the first 48 hr
• Chest x-ray with pulmonary infiltrates or pleural effusion
• CT scan/magnetic resonance cholangiopancreatography with pancreatic necrosis & extra pancreatic inflammation

Gallstone pancreatitis:

Gallstone pancreatitis develops when a gallstone passes through the biliary tree and obstructs the ampulla or flow from the pancreatic duct, allowing bile to reflux into the pancreas.  In addition to the classic manifestations of pancreatitis (eg, abdominal pain, nausea/vomiting, elevated serum lipase or amylase), patients with obstruction of the ampulla may also demonstrate cholestatic liver function studies (eg, elevated bilirubin, alkaline phosphatase, transaminases). 

If the stone remains in the biliary tract, the resultant bile stasis can allow bacteria to ascend from the duodenum, leading to acute cholangitis.  In addition to cholestatic liver function studies (due to stasis and obstruction), the presence of Charcot triad (right upper quadrant pain, jaundice, fevers) suggests the diagnosis, and altered mental status and hypotension (ie, Reynolds pentad) indicate particularly severe disease.  Common bile duct dilation  or choledocholithiasis on a right upper quadrant ultrasound further support the diagnosis. 

Management includes aggressive intravenous hydration and antibiotics.  Endoscopic retrograde cholangiopancreatography (ERCP) is indicated to relieve the biliary obstruction, during which a sphincterotomy, stone extraction, and/or biliary stent placement can be performed. 

Drugs Induced Pancreatitis:

Diuretics, including thiazides (eg, hydrochlorothiazide) and most loop diuretics (eg, furosemide), are among the most common offenders.  These drugs may trigger pancreatitis via 

•  hypersensitivity to the sulfonamide molecule (a structural component of thiazides and most loop diuretics)
•  pancreatic ischemia due to reduced blood volume 
•  increased viscosity of pancreatic secretions.   

   Other medications  statins (eg, simvastatin)which may act through similar or other pathophysiologic mechanisms (eg, direct toxicity). 

In addition to discontinuation of the offending agent, management of DIP is identical to that of other causes of acute pancreatitis, involving aggressive intravenous hydration, pain control, and diet advancement as tolerated. 

Complications of pancreatitis:

• Pseudocyst
• Peripancreatic fluid collection
• Necrotizing pancreatitis
• Acute respiratory distress syndrome
• Acute renal failure
• Gastrointestinal bleeding

Pancreatic Pseudocyst:

Acute pancreatitis can be complicated by a peripancreatic pseudocyst, a fluid collection (containing pancreatic enzymes, blood, fluid, and tissue debris) surrounded by a necrotic or fibrous capsule.  Pseudocysts typically take 3-4 weeks to develop after acute pancreatitis 

Pseudocysts are surrounded by a thick fibrous capsule .  They can leak amylase-rich fluid into the circulation and increase serum amylase.  

Complications include 

• spontaneous infection, 
•  duodenal or biliary obstruction,  
• pseudoaneurysm (due to digestion of adjacent vessels), 
•  pancreatic ascites 
•  pleural effusion.   

Abdominal imaging usually confirms the diagnosis. 

In patients with minimal or no symptoms and without complications (eg, pseudoaneurysm), expectant management (eg, symptomatic therapy, nothing by mouth) is preferred initially.  Endoscopic drainage is typically reserved for those  with significant symptoms (eg, abdominal pain, vomiting), infected pseudocyst, or evidence of pseudoaneurysm (usually embolized before drainage procedure).