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 30%

• Gallstones 35-40%

• Hypertriglyceridemia 1-4% cases

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

• Pancreatic tumor

• Post - ERCP

Management

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

Hemodynamic stability?

Unstable

{{{ E03 }}}

Stable

Trans abdominal USG

Labs: BUN, CBC, CXR, HCT, serum amylase, serum lipase, serum triglycerides, sr. creatinine

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

Acute Pancreatitis

SIRS?

{{{ yes }}}

No

Risk stratification (Marshall scoring)

Lower risk

Higher risk

Admit to medical ward

Admit to ICU

Fluids: Aggressive hydration at 250-500 ml/hr with Ringer's lactate in first 12-24 hrs Reassess within 6 hrs after admission and for next 24-48 hrs Analgesics: Opioids are preferred, Mepridine & Morphine may be used as IV drips/pt. controlled analgesia Nutrition: Immediate oral feeding as soon as pain, vomiting, nausea subside

Fluids: Initiate with a fluid bolus Aggressive hydration at 250-500 ml/hr with Ringer's lactate in first 12-24 hrs Reassess within 6 hrs after admission and for next 24-48 hrs Analgesics: Opioids are preferred, Mepridine & Morphine may be used as IV drips/pt. controlled analgesia Nutrition: Nasogastric or nasojejunal feeding may be initiated once pain, vomiting, nausea subside Consider enteral feeding if above not tolerated

Cholangitis or biliary obstruction

{{{ YES }}}

ERCP within 24 hrs/Cholecystectomy to prevent recurrence

No

Consider MRCP/EUS

Clinical improvement within 48-72 hrs

{{{ YES }}}

Assess for ability to maintain oral feeding at the end of 1 week

N o

CECT/MRI

Recovery

Pancreatic necrosis

Failure to improve clinically after 7-10 days of hospitalization

Yes

Supportive treatment

No

Suspect Infected necrosis

CT guided FNA Empiric antibiotics, necrosis penetrating: meropenem 1g IV Q8h ciprofloxacin 400mg IV Q12h plus metronidazole 500 mg IV Q8h for 14 days

Gram stain & Culture (-)

Supportive treatment Consider repeat CT FNA every 7 days if no improvement

Gram stain & Culture(+)

Infected Necrosis

Clinically stable

Clinically unstable

Continue antibiotics & observe If asymptomatic no debridement, else consider surgical consultation

Prompt surgical consultation

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-acquired 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

• ERCP is not needed in most pts. with gallstone pancreatitis, esp. if they lack clinical or laboratory evidence of ongoing biliary obstruction.
• Do not shift patients with sepsis/organ failure to general ward.
• Do not perform emergency surgery, radiologic or endoscopic drainage in stable patients with infected necrosis, wait for 3-4 weeks for the development of a fibrous wall around the necrosis.
• Routine use of antibiotics as prophylaxis is not recommended in acute pancreatitis.
• In pts. with sterile necrosis, routine antibiotics are not recommended to prevent development of infected necrosis.
• Anti-fungal agents are not recommended for prophylaxis or therapeutic use along with routine antibiotics.
• In a pt. with necrotizing biliary AP, cholecystectomy should be delayed until active inflammation has subsided to prevent infection.