Acute pancreatitis resident survival guide

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Vidit Bhargava, M.B.B.S [2]

Definition

Diagnostic Criteria

• Diagnosis is established by the presence of two of the three following criteria:

[1] Abdominal pain consistent with acute pancreatitis.

▸ Acute onset of a persistent, severe, epigastric pain often radiating to the back.

[2] Serum lipase or amylase ≥ 3 x ULN.

[3] Characteristic findings on contrast-enhanced CT, MRI, or transabdominal US.

Types of Acute Pancreatitis

Interstitial Edematous Pancreatitis

• Acute inflammation of the pancreatic parenchyma and peripancreatic tissues, but without recognizable tissue necrosis.

CECT criteria

▸ Pancreatic parenchyma enhancement by intravenous contrast agent.

▸ No findings of peripancreatic necrosis.

Necrotizing Pancreatitis

• Inflammation associated with pancreatic parenchymal necrosis and/or peripancreatic necrosis.

CECT criteria

▸ Lack of pancreatic parenchymal enhancement by intravenous contrast agent.

▸ Presence of findings of peripancreatic necrosis.

Infected Pancreatic Necrosis

• Should be considered in patients with necrotizing pancreatitis who deteriorate or fail to improve after 7–10 days of hospitalization.

• May be presumed by the presence of extraluminal gas on CECT or when fine-needle aspiration is positive for bacteria and/or fungi on Gram stain and culture.

• Antibiotics able to penetrate pancreatic necrosis (such as carbapenems, quinolones, and metronidazole) may be useful in delaying or sometimes totally avoiding intervention.

Complications

Organ Failure

• Organ failure is defined as a score of 2 or more for one of these three organ systems using the modified Marshall scoring system.

• Transient organ failure = organ failure resolves within 48 h
• Persistent organ failure = organ failure persists for >48 h

Modified Marshall Scoring System

Organ System	0	1	2	3	4
Respiratory PaO2/FiO2	>400	301-400	201-300	101-200	≤101
Renal† Creatinine (μmol/l) Creatinine (mg/dl)	≤134 <1.4	134-169 1.4-1.8	170-310 1.9-3.6	311-439 3.6-4.9	>439 >4.9
Cardiovascular Systolic Blood Pressure (mmHg)	>90	<90, fluid responsive	<90, not fluid responsive	<90, pH <7.3	<90, pH <7.2

^† A score for patients with pre-existing chronic renal failure depends on the extent of further deterioration of baseline renal function. No formal correction exists for a baseline creatinine ≥134 μmol/l or ≥1.4 mg/dl.

Local Complications

• Should be suspected when there is persistence/recurrence of abdominal pain, secondary increases in pancreatic enzyme, increasing organ dysfunction, or the development of signs of sepsis.

Acute Peripancreatic Fluid Collection (APFC)

• Peripancreatic fluid associated with interstitial edematous pancreatitis with no associated peripancreatic necrosis. This term applies only to areas of peripancreatic fluid seen within the first 4 weeks after onset of interstitial edematous pancreatitis and without the features of a pseudocyst.

CECT criteria

▸ Occurs in the setting of interstitial edematous pancreatitis.

▸ Homogeneous collection with fluid density.

▸ Confined by normal peripancreatic fascial planes.

▸ No definable wall encapsulating the collection.

▸ Adjacent to pancreas (no intrapancreatic extension).

Pancreatic Pseudocyst

• An encapsulated collection of fluid with a well defined inflammatory wall usually outside the pancreas with minimal or no necrosis. This entity usually occurs more than 4 weeks after onset of interstitial edematous pancreatitis to mature.

CECT criteria

▸ Well circumscribed, usually round or oval.

▸ Homogeneous fluid density.

▸ No non-liquid component.

▸ Well defined wall; that is, completely encapsulated.

▸ Maturation usually requires >4 weeks after onset of acute pancreatitis; occurs after interstitial edematous pancreatitis.

Acute necrotic collection (ANC)

• A collection containing variable amounts of both fluid and necrosis associated with necrotizing pancreatitis; the necrosis can involve the pancreatic parenchyma and/or the peripancreatic tissues.

CECT criteria

▸ Occurs only in the setting of acute necrotising pancreatitis.

▸ Heterogeneous and non-liquid density of varying degrees in different locations (some appear homogeneous early in their course).

▸ No definable wall encapsulating the collection.

▸ Location—intrapancreatic and/or extrapancreatic.

Walled-off necrosis (WON)

• A mature, encapsulated collection of pancreatic and/or peripancreatic necrosis that has developed a well defined inflammatory wall. WON usually occurs >4 weeks after onset of necrotising pancreatitis.

CECT criteria

▸ Heterogeneous with liquid and non-liquid density with varying degrees of loculations (some may appear homogeneous).

▸ Well defined wall, that is, completely encapsulated.

▸ Location—intrapancreatic and/or extrapancreatic.

▸ Maturation usually requires 4 weeks after onset of acute necrotizing pancreatitis.

Causes

Life Threatening Causes

Life-threatening causes include conditions which may result in death or permanent disability within 24 hours if left untreated.

Acute pancreatitis from any cause may be life-threatening especially if it progresses to necrotizing pancreatitis.

Common Causes

• Alcohol

• Gallstones

• Hypertriglyceridemia

• Idiopathic

• Infections

• Ischaemic necrosis of pancreas from vascular sources such as vasculitis and atherosclerosis

• Medication such as 5-mercaptopurine, azathioprine, 5-DDI

• Metabolic - hypercalcemia and hyperphosphatemia

• Smoking

• Pancreatic tumor

• Post - ERCP

• Pregnancy

• Toxins such as venom of brown recluse spider, certain arachnids etc.

• Trauma

Management

Acute Pancreatitis

Signs & symptoms: severe abdominal pain, breathing difficulty, hypotension, vomiting, fever, cullen's sign, grey turner sign

Check labs - serum amylase, serum lipase, serum triglycerides, abdominal USG, CBC, CECT, MRI

Diagnostic criteria: Any 2 out of 3 Abdominal pain consistent with disease serum amylase or lipase values > 3 times normal consistent findings from abdominal imaging

Risk stratification

Low risk*

High risk**

General medical ward

ICU

Initiate supportive care Aggressive fluid resuscitation with 250-500 mlRingers Lactate per hr during first 12-24 hours In sever cases give fluid bolus Mild cases - oral liquid feeds In moderate to severe cases enteral feeds, nasogastric or nasojejunal feeds are acceptable

CT scan

Provide adequate analgesia

Pancreatic necrosis

Stones?

Other causes, treat as per cause

No

Yes

Surgical consult Emergency cholecystectomy or ERCP within 24 Hrs of admission

Assess in 1 week

SIRS/Organ failure?

Tolerating oral feeds

Not tolerating oral feed

If yes, surgical consultation Think about CT guided percutaneous aspiration & culture

Recovery

Add nutritional support Consider CT scan

Lack of improvement/Worsening of clinical status

• * - Low risk: 1. Absence of organ failure. and/or 2. Absence of local complications
• ** - High risk: 1. Transient organ failure. and/or 2. local complications.

The following recommendations are based on 2013 guidelines for Acute pancreatitis treatment based on recommendations given by American college of gastroenterology.

Do's

• Perform abdominal USG in all patients.
• Check serum triglycerides if stones/alcohol not not an etiology.
• Consider pancreatic tumor if age > 40 yrs.
• Use Ringer's Lactate(RL) as first choice agent, use normal saline if RL not available.
• Refer patients with idiopathic acute pancreatitis to centers of excellence.
• Perform elective cholecystectomy for gallstones to prevent recurrences.
• Use antibiotics for infected necrosis, with high penetrance such as carbapenems, quinolones & metronidazole.
• CECT or MRI should be reserved for:

• Patients who fail to improve clinically (e.g., persistent abdominal pain, fever, nausea, unable to begin oral intake) within the first 48-72 h after admission.
• Patients in whom the diagnosis is unclear.

Dont's

• Do not shift patients with sepsis/organ failure to general ward.
• Do not perform emergency surgery in stable patients with infected necrosis, wait for 3-4 weeks.