- Pancreatitis is a sterile inflammatory process. Bacterial infection may coexist or develop in previously sterile sites. However, the routine use of antibiotics is not recommended in national guidance.
- In a forward medical location, limited access to investigations are likely to mean that it is impossible to definitively establish the diagnosis. In the context of this diagnostic uncertainty and due to the risk of other infective causes (such as cholangitis), empirical antibiotic therapy is likely to be justified.
- At higher levels of care where further investigations are likely to be available to confirm a diagnosis of acute pancreatitis, antibiotics may be stopped unless there is a high suspicion of infection.
Acute Pancreatitis
Warning
Objectives
To guide the management and investigations of suspected acute pancreatitis in the deployed environment.
Scope
This guideline describes the management of patients with suspected acute pancreatitis in a forward medical context or deployed Emergency Department.
The clinical presentation of pancreatitis mimics other upper abdominal conditions including gastritis, peptic ulcers, perforation and biliary disease; the diagnosis cannot be established or refuted without CT scanning and amylase testing. Accordingly, these guidelines specify a safe approach to management of suspected pancreatitis in a forward location that deviates from standard management in some respects. At higher echelons of care, investigations are likely to be available to allow confirmation of diagnosis and more thorough assessment of severity or complications.
There are separate guidelines for cholecystitis and biliary tract pathologies.
Audience
This guideline is intended for the use of registered healthcare professionals fulfilling a general role in a forward medical location or in an Emergency Department on deployed operations.
Initial Assessment & Management
Background
Acute pancreatitis is a relatively common, potentially life-threatening condition characterised by inflammation and auto-digestion of the pancreas.
Patients with acute pancreatitis can present anywhere along the spectrum of illness severity, from ambulatory to critically unwell.
In a civilian population 70% of acute pancreatitis cases are caused by gallstones and alcohol misuse. In the deployed environment other less common causes (such as toxins, drugs, viral infections and scorpion stings) should also be considered.
History
Usually, severe abdominal pain: continuous and boring in nature, upper abdominal pain; 50% have band-like radiation to the back.
Often, nausea and vomiting, anorexia, fever and chills.
Rarely, dyspnoea, steatorrhoea (late).
Examination
Usually, tenderness/guarding in upper abdomen.
Often, tachycardia, pyrexia.
Unusually, jaundice.
In severe disease, hypotension, oliguria, altered mental state, ascites.
Severity scoring is discussed in the accordion content below, but for the purposes of this guideline, in a forward medical location, a mild case is one characterised by pain with normal observations, preserved urine output, normal mental state and continued ability to drink.
Management
Oxygen: Utilise supplemental oxygen to aim for SaO2 >94%.
Fluid resuscitation: in mild pancreatitis, intravenous fluids may not be required if the patient is tolerating oral fluids and is clinically euvolaemic. Where this is not the case, Hartmanns or other balanced crystalloid are preferred, or otherwise normal saline, with a bolus of 20ml/kg if evidence of shock. Larger volumes may be required in more severe cases: the patient should be catheterised and the urine output monitored. Fluid input should be as titrated to maintain urine output, and consideration should be given to environmental conditions to account for insensible losses. Fluid infusions can be stopped once adequate oral fluids are tolerated.
Monitoring goals: urine output of 0.5ml/kg/hr. In mild cases, 4 hourly observations; if there is evidence of organ dysfunction, hourly observations.
Analgesia: analgesic requirements are likely to be significant in patients with acute pancreatitis, requiring opioids. NSAIDS should be avoided. Avoid paracetamol if jaundice present.
Antibiotics: empirical antibiotics are a reasonable adjunct in the undifferentiated/suspected pancreatitis patient in a forward location. IV antibiotics should be administered in accordance with deployed antimicrobial guidance for non-traumatic intra-abdominal infection.
Anti-emetics: nausea and vomiting are likely to be present. Anti-emetics should be used routinely to reduce these symptoms.
Nutrition: Patients with mild disease can eat. Others should be kept nil by mouth until discussion with a specialist or transfer to a higher echelon of care. Following adequate resuscitation, intravenous maintenance fluids may be utilised to maintain fluid status.
Evacuation: Although patients may be able to be temporised in a forward location, evacuation should be considered early as there is significant potential to deteriorate. Mild cases of pancreatitis will normally require evacuation even if symptoms have fully resolved, as there is a need to investigate aetiology and seek to prevent recurrence. The management of patients in the event of delayed evacuation is described below.
Advanced Assessment & Management
Patients who present or are evacuated to a higher level care should be managed with the following additional considerations:
Monitoring goals: continue to aim for urine output of 0.5ml/kg/hr but additionally a mean arterial pressure (MAP) ≥ 65.
Bloods: when available, test venous blood gas, full blood count, liver function and either amylase or lipase as available (lipase is a more specific test than amylase but access to either investigation will depend on reagent availabity).
An amylase level or lipase level greater than 3 times the upper limit of normal range are both diagnostic of pancreatitis. Lower levels may be consistent with other upper abdominal pathologies. Be aware that amylase typically normalises within 3-5 days regardless of disease severity, and lipase within 4-8 days.
Imaging: An erect chest X-ray should be performed as the differential diagnosis includes perforation. Trans-abdominal ultrasound for gallstones and biliary dilatation is required. CT (contrast-enhanced) scan should be utilised if available where there is diagnostic uncertainty or in patients that become systemically unwell, septic or fail to improve.
Nutrition: patients with mild acute pancreatitis can eat and drink as soon as pain allows. There is no evidence to support early enteral nutritional support. Enteral feed should be considered if normal diet cannot be established within 72 hours. If enteral feeding fails then parenteral will be needed. Pancreatic exocrine replacement therapy is unlikely to be available within the deployed setting and is not required for most patients.
Advanced Analgesia: where expertise permits, erector spinae plane block (regional anaesthesia) has shown efficacy. Effective pain control is vital to preventing complications.
Pulmonary Complications: Early effective analgesia aims to prevent complications associated with ‘diaphragmatic splinting’ and hypoventilation, as acute pancreatitis is a potent stimulus for ARDS. Following initial resuscitation, fluid administration should be minimised and guided by haemodynamic monitoring. High flow nasal oxygen may avoid the need for more invasive ventilatory support.
Antibiotics: antibiotics should be rationalised once further investigations are available. In the absence of proven or high suspicion of infection, they should be stopped.
Prolonged Casualty Care
If evacuation to a higher level of care is delayed, the following considerations should be applied:
Fluid balance: intravenous fluids should be given to maintain adequate organ perfusion in those who cannot take fluids orally. Measure urine output (via urinary catheter or otherwise) and target >0.5ml/kg/hour.
Analgesia: a regular analgesia plan should be devised. IV preparations should be used unless confident of enteral absorption. NSAIDs should be avoided. Regular opioids are likely to be required.
Antibiotics: empirical antibiotics should be continued if evacuation is delayed.
Nutrition: patients with mild symptoms may trial oral nutrition as pain and nausea allows. Those with severe symptoms should remain nil by mouth pending evacuation. If over 72 hours, feeding must be attempted.
- Although a number of prognostic tools have been developed for acute pancreatitis, none have been shown to be inferior or superior to SIRS criteria at predicting mortality, and the results required to calculate most risk scores are unlikely to be available in the deployed setting, making them invalid.
- Clinical gestalt, evidence of organ failure and SIRS should be used to assess severity and inform discussions around urgency of evacuation.
Systemic Inflammatory Response Syndrome (SIRS) Criteria - two or more of
Temp >38°C or <36°C
Heart rate >90
Respiratory rate >20 or PaCO₂ <32 mm Hg
White cell count >12,000/mm³, <4,000/mm³, or >10% bands
-
CRP level at 48 hours after onset of symptoms is a good indication of severity: 150mg/l or higher is predictive of necrosis. CT imaging, one week or more after onset (when necrosis can be seen) is therefore mandatory in patients whose 48hr CRP is above 100mg/l.
Only a small minority of patients with acute severe pancreatitis will require endoscopic, radiological, or surgical intervention. Where necessary, intervention is directed at drainage of necrosis and not indicated within the first few weeks of the disease.
For patients with severe acute pancreatitis, critical care and organ support is the mainstay of treatment and relies upon early recognition and evacuation.