section name header

Information

Editors

ElisaMäkäräinen

Acute Abdomen in the Adult

Essentials

  • Decisions on the need for further investigations and on the urgency of treatment, and beginning treatment quickly, as necessary, are of primary importance.
  • Abdominal computed tomography (CT) is a basic investigation of an acute abdomen, unless cholecystitis is suspected, in which case abdominal ultrasonography should be performed.

Aetiology

Surgical causes and diagnostic clues for acute abdomen

CauseDiagnostic clues
Appendicitis Acute AppendicitisCommon.
The probability of appendicitis can be assessed using the Adult Appendicitis Score (AAS) calculator http://www.appendicitisscore.com/, for example.
Intestinal obstruction Obstruction of the Small or Large Bowel, Paralytic Ileus and Pseudo-ObstructionSmall bowel obstruction is most commonly due to adhesions from previous surgical treatment.
The most common cause of large bowel obstruction is a tumour.
Suspect intestinal ischaemia if the patient is in pain despite a functional nasogastric tube.
Intestinal perforationSeveral hours to several days from symptom onset
Often peritonitis
Mere suspicion of intestinal perforation is an indication for starting antimicrobial treatment.
Further investigations and treatment immediately
Acute cholecystitis CholelithiasisThe typical symptom is pain starting after a meal in the right upper abdomen that does not subside during follow-up.
Abdominal ultrasonography is the first-line investigation if acute cholecystitis is suspected.
Acute pancreatitis Acute PancreatitisTypically band-like pain predominantly in the left upper abdomen
An increased amylase concentration makes the suspected diagnosis more probable.
Suspect cholangitis and/or biliary pancreatitis if liver values are increased.
If the amylase level is elevated and acute pancreatitis is suspected, CT should preferably be done only after 72-96 hours from the onset of symptoms.
Mesenteric ischaemiaThe clinical picture may be vague.
In patients over 70, triphasic abdominal CT should be performed, including the arterial phase to facilitate a more specific diagnosis.
In acute mesenteric ischaemia, further treatment must be provided urgently.
Complicated diverticulitis of the colon Diverticulitis and DiverticulosisThe most common site is the sigmoid colon.
Perforation may be either restricted, forming an abscess, or spread to cause generalized peritonitis.
VolvulusThe most common site is the sigmoid colon, in the left lower abdomen, but volvulus of the caecum is also fairly common.
Typically drum-like potbelly
Testis torsion Testis PainSore testis tender on palpation particularly in children
Explorative surgery should be readily performed.
Incarcerated herniaRapid repositioning of the hernia is of primary importance.
If the hernia can be repositioned and no suspicion of irreversible intestinal ischaemia arises, the patient can usually be discharged. Nevertheless, they should be referred for assessment of need for surgery. See also Hernias in Adults.
  • See picture 1

Gynaecological causes for acute abdomen; examples and clues Lower Abdominal Pain of Gynaecological Origin

CauseDiagnostic clue/example
Ectopic pregnancy Ectopic PregnancyPain; referred pain in shoulder. Urine pregnancy test may be negative, rapid serum test is usually positive.
Ovarian originOvulation pain, oophoritis, ruptured cyst, torsion of a cyst.
Myoma Benign Gynaecological Lesions and TumoursTorsion; necrosis; bleeding into the abdominal cavity, infection
Endometriosis EndometriosisMenstrual pain

Non-surgical causes for acute abdomen (examples)

CauseExamples
Metabolic disorders
Diabetic ketoacidosis Diabetic Ketoacidosis
Porphyria Porphyrias
Hypertriglyceridaemia (pancreatitis)
Hyperparathyroidism (pancreatitis) Hypercalcaemia and Hyperparathyroidism
Uraemia
Pain conditions associated with haematological diseases
Haemochromatosis Haemochromatosis
Addisonian crisis Addison's Disease and other Conditions Inducing Hypocortisolism
Mushroom and heavy metal poisonings
Infectious causes
Gastroenteritis Acute Diarrhoeal Disease in a Traveller
Inflammatory bowel disease (IBD; Crohn's Disease Ulcerative Colitis
Hepatitis Viral Hepatitis
Perihepatitis
Mononucleosis Mononucleosis
Herpes zoster Shingles (Herpes Zoster)
Pyelonephritis Urinary Tract Infections
Prostatitis, epididymitis, orchitis Testis Pain
Sepsis Sepsis
Referred pain
Myocardial infarction Acute Coronary Syndrome
Pericarditis Pericarditis
Pneumonia Pneumonia
Pleuritis Pleural Effusions and Thoracentesis
Pulmonary infarction or embolism Pulmonary Embolism
Spontaneous pneumothorax Pneumothorax
Heart failure (hepatic stasis) Acute Heart Failure and Pulmonary Oedema
Renal calculi Urinary Calculi
Haematoma of the rectus abdominis muscle
Immunological disorder
Angioneurotic oedema Hereditary Angioedema (HAE) and ACE Inhibitor-Induced Angioedema
Polyarteritis nodosa Vasculitides
Henoch-Schönlein purpura Henoch-Schönlein Purpura
Allergy
Eosinophilic gastroenteritis, enteritis or colitis

Investigations

History

  • Pain history
  • Any underlying diseases and regular medication
  • History of abdominal surgery
  • Is this a new acute problem or an exceptionally severe exacerbation of prolonged pain?
  • Vomiting, nausea, bladder and bowel function
  • Obstipation is most often chronic. A change in bowel habits is an important symptom.

Clinical examination

  • An always careful general examination
    • Auscultation of the heart and lungs
    • Measurement of blood pressure and heart rate
    • General neurological examination
  • Inspection of the abdomen
    • Form and plumpness of the abdomen
    • Surgical scars
    • Skin changes
    • Hernias (visible or palpable)
  • Palpation of the abdomen
    • Abdominal wall (tender or pain-free, soft or tense suggesting peritoneal irritation, guarding)
    • The location of maximal pain
    • Palpable masses, hernial orifices, tautness and ascites
  • Palpation of the genitals
    • Hernias
    • Pain or swelling of the testes or epididymis
    • Scrotal hydrocele
  • Digital rectal examination
    • Palpable masses, bleeding
    • Prostate: size, consistency, nodules
    • Any faeces in the rectal ampulla, the colour of the faeces

Laboratory tests

  • If the patient is unwell or clearly ill, further investigations should be arranged without waiting for laboratory results.
  • Today, accident and emergency clinics commonly use laboratory packages.
  • It is usually sufficient to do basic blood count with platelet count, CRP, chemical screening of urine, in suspected pancreatitis plasma pancreatic amylase, in suspected cholecystitis ALT, ALP, bilirubin, glucose, sodium and potassium. Also note blood glucose and, as necessary, blood gas analysis.
  • If a cardiac cause is suspected, an electrocardiogram (ECG) and TnI/TnT test should always be taken.
  • In women below 50, hCG should be tested.
  • Normal laboratory results do not exclude conditions such as mesenteric ischaemia; if this is suspected, laboratory results should not be waited for.

Imaging

  • Ultrasound examination
    • The primary examination in the diagnostic workup for acute cholecystitis
    • Ultrasonography (or "sonopalpation") is also useful when performed by a doctor on call Ultrasonographic Examinations.
  • Abdominal CT scan is the primary imaging method in the diagnostic workup of abdominal pain
    • If there is clear suspicion of pancreatitis, to improve the diagnostic results CT should preferably only be performed 72-94 hours after the onset of symptoms.
    • In patients over 70, the possibility of mesenteric ischaemia should be kept in mind and the arterial phase included in imaging..
  • Chest x-ray as necessary
    • Look for pleural effusion, pericarditis or heart failure, pulmonary infections or shadows.

Emergency treatmentAnalgesia in Patients with Acute Abdominal Pain

  • During the diagnostic investigations, the degree of metabolic disorder should be assessed and fluid therapy should be started before transport to a hospital, unless the distance is very short.
  • Start measuring urine output.
  • A nasogastric tube should be inserted without hesitation if the patient keeps vomiting.