Acute Pancreatitis I

Incidence of mild vs severe acute pancreatitis

80% of cases mild, 20% severe.

Ranson's score

>70 yo, glucose >12.2 mmol/L, leukocytosis, raised AST and LDH.

Chvostek's sign and Trousseau's sign.

Chvostek's sign- facial muscle spasm when facial nerve is tapped. Trousseau's sign- carpopedal spasm when BP cuff is applied.

Treatment of pancreatic pseudocysts

Internal drainage > external drainage. 6 weeks after (allow development of pseudocapsule). Surgical or endoscopic cystogastronomy.

Anti-proteolytic factors in the pancreas

Intracellular pancreatic trypsin inhibitor protein, circulating B2-macroglobulin, alpha1-antitrypsin and Cl-esterase inhibitors.

Short term pancreatic complications of acute pancreatitis

Necrosis (secondary to inadequate fluid resus, vasoactive and toxic substances and often infected), abscess (circumscribed collection of pus- when peri-pancreatic fluid becomes infected) and pseudocyst.

Empirical antibiotics for acute pancreatitis

Not routinely given unless signs and symptoms of infection. Imipenem/cilstatin OR ceftrizone/ampicllin/ciprofloxacin.

Pathological classification of acute pancreatitis

Oedematous pancreatitis (pancreas and surrounding structures engorged with interstitial fluid) and haemorrhage pancreatitis (bleeding into the parenchyma and surrounding structures).

Symptoms of acute pancreatitis

pain, marked epigastric tenderness (guarding and rebound tenderness not in early stages), nausea and vomiting, anorexia, fever, tachycardia.

Long term pancreatic complications of acute pancreatitis

pancreatic insufficiency (usually exocrine) and chronic pancreatitis.

Ddx for acute pancreatitis

perforate viscus, acute cholecystitis and MI.

Serum amylase measurement

rises in first 2-12 hours, cleared by kidneys and may disappear 24-48 hours. 3x upper limit of normal. No prognostic value. Persistently elevated if pseudocyst.

Glasgow criteria/Imrie's criteria

score 3 or more: >55 yo, hypoxic, leukocytosis, low albumin, hypocalcaemia, hyperglycaemia (>10mmol/L), urea >16 after rehydration, raised ALT and LDH.

Cause of late death from acute pancreatitis

sepsis

Common causes of acute pancreatitis

Gallstones and alcohol most common. Idiopathic (10-20%) and post-ERCP also common.

Signs of severe acute pancreatitis

Hypoxia, hypovolaemia shock, oliguria, Grey-turner's sign, Cullen's sign, Fox's sign, abdominal distension, hypotension, signs of hypocalcaemia (Chvostek's sign and Trousseau's sign).

Treatment of pancreatic pseudocyst

If >5cm and not resolved in 12 weeks, then excision/external drainage/internal drainage.

Balthazar classification

A-E- Based on extent of pancreatic inflammation and presence of fluid collection or evidence of necrosis.

Indicators of severe acute pancreatitis on presentation

BMI >30, pleural effusion, APACHE II score >8.

Secondary prevention of acute pancreatitis

Balanced low fat diet, TAG control (statin use), reduce alcohol consumption.

Treatment of alcohol-induced pancreatic disease

Benzodiazepines as alcohol-withdrawal prophylaxis, vitamin and mineral replacement (thiamine, folic acid and cyanocobalamin).

Correction of metabolic abnormalities in acute pancreatitis

Correct hyperglycaemia with insulin (keep <8.33 mol/L), correct hypocalcaemia with IV calcium if tetany occur, magnesium replacement therapy (commonly needed in alcoholic patients- check renal function first).

Pathophysiology of ethanol-induced pancreatitis

Direct toxic insult to the acing cell causing inflammation and membrane destruction.

Fox's sign

Ecchymosis (subcutaneous bleeding) over the inguinal ligament area.

Nutritional support in acute pancreatitis

Enteral feeding required, initially nil by mouth. Reduces endotoxaemia and reduced pancreatic activation. NG or NJ tube over TPN.

Other investigations for acute pancreatitis

FBC/WBC, haematocrit, albumin, serum Ca, glucose, urea, AST/ALT, LDH, serial measurement of CRP (prognostic) ABGs, XRs (GI and pulmonary complications), MRCP, ERCP and fine needle aspiration (infection suspected).

Development of pancreatic ascites

Fluid leaks from pancreatic duct into the peritoneal cavity. Leakage into the thoracic cavity can cause pleural effusion.

Pathophysiology of acute pancreatitis

Following trigger, build up of pro-enzymes and so activated enzymes (trypsin) leading to acinar cell destruction. Inflammation often spreads to neighbouring structures.

Risk factors for acute pancreatitis

Middle-aged women, young to middle-aged men, gallstones, alcohol, hypertriglyceridemia, causative medications, ERCP, HIV/AIDS, SLE and Sjogren's syndrome.

Cause of early death from acute pancreatitis

Multi-organ failure

Treatment of infected pancreatic necrosis.

Percutaneous needle aspiration, necrosectomy (better outcomes if wait until the necrosis is organised), somatostatin analogues may reduce preoperative complications.

Cullen's sign

Peri-umbilical blue discolouration indicating haemorrhage pancreatitis.

Diagnosis of acute pancreatitis

Raised serum amylase or lipase concentration and US/CT evidence of pancreatic swelling.

Development of a pseudocyst

Rupture of the pancreatic duct allows fluid to collect in the lesser sac, fibrous capsule surrounding fluid develops over a 6-week period. Symptoms- asymptomatic or constant abdominal pain/palpable abdominal mass.

Pain of acute pancreatitis

Severe, sudden-onset, constant abdominal pain. Increasing in intensity over 15-60 minutes. Radiate to the back.

Systemic complications from acute pancreatitis

Systemic inflammatory response syndrome, Acute respiratory distress syndrome, DIC, hyperglycaemia, hypocalcaemia, reduced albumin (increased capillary permeability).

GI complications of acute pancreatitis

Upper Gi bleed, vatical haemorrhage, obstruction, obstructive jaundice.

Resuscitation in acute pancreatitis

aggressive fluid resuscitation (crystalloid- central venous line and urinary catheter in patients with shock), analgesia, antiemetic (ondansetron), correct hypoxia (oxygen or ventilator support), thromboembolism prophylaxis and blood transfusion if haemorrhagic.

Grey-turner's sign

bilateral flank blue discolouration indicating haemorrhage pancreatitis.

US findings in acute pancreatitis

confirm gross swelling, can exclude gallstones, biliary obstruction or pseudocyst formation.

Principles of acute pancreatitis treatment

early resuscitation, detect and treat underlying cause and prevent complications.

Serum lipase measurement

greater specificity than serum amylase. Levels rise 4-8 hours, last for 8-14 days.

Rare causes of acute pancreatitis

hypercalcaemia, hypertriglyceridaemia, pancreatic malignancy, trauma, infections (mumps, mycoplasma etc.), drugs (diuretics, azathioprine, valproic acid etc.), autoimmune conditions, pancreas divisum, sphincter of Oddi dysfunction, hereditary, post-surgical, renal failure, organ transplantation, severe hypothermia, petrochemical exposure, hyperparathyroidism and periempullary cancer.

Contrast enhanced pancreatic CT

if diagnosis equivocal or if persisting organ failure. May identify necrosis.

Causes of raised serum amylase

intestinal ischaemia, perforated peptic ulcer, ruptured ovarian cyst and salivary isoenzyme raised in parotitis.