ACUTE ABDOMINAL PAIN
- Analgesia early in assessment usually improves the accuracy of abdominal findings
- Early IV access, surgical opinion, fluid resuscitation prior to completing assessment if patient is shocked
- don’t just focus on the abdomen e.g. cardiothoracic conditions in upper abdominal pain such as acute MI, oesophageal rupture, pneumonia; or testicular pathology in lower abdominal pain
- beware of ischaemic bowel where pain is out of proportion to abdominal findings
- recurrent bouts of abdominal pain can be diagnostically challenging after standard investigation e.g. lead poisoning, porphyria
- in puzzling cases consider acute medical causes of abdominal pain e.g. DKA
ASSESSMENT
- There are many causes for acute abdominal pain so it important to follow the Principles of a Systematic Assessment
- Classic presentations do occur but there often are atypical features and specific pattern recognition is not useful
- Focus on the chronology which gives an indication of urgency alongside location and character of pain. This and the associated symptoms greatly assists at narrowing down the possibities to the likely culprit organ, the pathological process and best investigative strategy
- Beware of abrupt or rapid onset of severe abdominal pain
- Consider non intra-abdominal causes of abdominal pain
- Review risk factors for disease – previous surgical intervention, family history, alcohol use, smoking, NSAID use
- Briefly review anaesthetic / Peri-operative risk e.g. current physiological status cardio-respiratory co-morbidities, previous anaesthetics, anticogulant use, fasting status
See Acute abdomen Assessment Form (printable form)
Examination
- Abnormal vital signs give clues to serious pathology e.g. sepsis, third-spacing, internal haemorrhage
- Evaluate hydration
- Identify signs of peritonism
COMMON TRAPS
- Constipation should not be considered a diagnosis before it is a considered a symptom (of something serious)
- Diagnosing renal colic in a AAA
- Ignoring the vital signs
- Severe abdominal pain without abdominal findings = ischaemic bowel
INVESTIGATIONS
Depending on clinical assessment, severity of symptoms and likelihood of acute pathology
For more than mild symptoms in non-specific abdominal pain.
- Full blood Count
- Electrolyte and renal function
- Urinalysis (most patients)
- BHCG (if fertile woman regardless of contraceptive or sexual history)
- ECG (in upper abdominal pain without abdominal findings)
Otherwise investigations should be selective according to the suspected pathology
High patient risk groups
Examination unreliable
- Elderly and children
- Intellectually disabled
- Spinal patients
- Immuno-compromise
Persistent or recurrent symptoms
- ‘Second presentation’
- ‘Came in the middle of the night’
DISPOSITION
Immediate surgical consultation (may need urgent laparotomy without further imaging)
- Severe bleeding
- Hypotension
- Severe metabolic acidosis
Indications for admission
- Active GI bleeding
- Bilious vomiting
- Abnormal vital signs
- Elevated inflammatory markers
- Abnormal acid-base or elevated lactate
- Peritonism
- Free fluid, free gas or signs of obstruction on abdominal imaging
- Ongoing pain in high-risk patients
Discharge Criteria
- Uncomplicated infection e.g. UTI, gastroenteritis
- Mild pain
- Tolerating fluids/Not vomiting
- Afebrile
- Not tachycardic
- No peritonism
- Investigations normal