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]

Diagnostic Criteria

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

• Abdominal pain consistent with acute pancreatitis (acute onset of a persistent, severe, epigastric pain often radiating to the back).
• Serum lipase or amylase ≥ 3 x ULN.
• Characteristic findings on contrast-enhanced CT, MRI, or transabdominal US.

Types

• 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

• Modified Marshall Scoring System

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 of 2 or more in any system defines the presence of organ failure.
^‡ 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.

▸ For non-ventilated patients, the FiO2 can be estimated from below:

Supplemental oxygen (l/min)	FiO2 (%)
Room air	21
2	25
4	30
6–8	40
9–10	50

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

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

Systemic Complications

▸ Defined as exacerbation of pre-existing co-morbidity, such as coronary artery disease or chronic lung disease, precipitated by the acute pancreatitis.

Grades of Severity

• Mild acute pancreatitis

▸ No organ failure

▸ No local or systemic complications

• Moderately severe acute pancreatitis

▸ Organ failure that resolves within 48 h (transient organ failure) and/or

▸ Local or systemic complications without persistent organ failure

• Severe acute pancreatitis

▸ Persistent organ failure (>48 h)

– Single organ failure

– Multiple organ failure

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

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

• Pancreatic tumor

• Post - ERCP

Do's

• 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.

• Perform abdominal USG in all patients.
• Check serum triglycerides if stones/alcohol not an etiology, consider etiology if sr. triglycerides > 1000 mg/dl
• Consider pancreatic tumor if age > 40 yrs.
• Use Ringer's Lactate(RL) as first choice agent, use normal saline if RL not available.
• Pancreatic duct stents or post-procedure NSAID's are recommended to prevent post-ERCP pancreatitis.
• Perform elective cholecystectomy for gallstones to prevent recurrences.
• Antibiotics are given for extra-pancreatic infections such as cholangitis, catheter-acuired infections, bacteremia, UTI's, pneumonia.
• Use antibiotics for infected necrosis, with high penetrance such as carbapenems, quinolones & metronidazole.
• Presence of asymptomatic pancreatic necrosis or asymptomatic pseudocysts do not warrant intervention, regardless of size, location, extension.

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.