Define Acute abdomen
Recent or sudden onset of unexpected signs or symptoms including abdominal pain
What is the significance of acute abdomen?
Potential for life-threatening infection or fluid/blood loss
Name 2 causes of abdominal visceral pain
- Ischaemia
- Distension
- Tension - often colicky
What areas can be involved in Epigastric pain?
- Stomach to the 2nd part of duodenum
- Liver and biliary tree
- Pancreas and spleen
What areas can be involved in Periumbilical pain?
2nd part of duodenum to proximal 2/3 transverse colon
What areas can be involved in Suprapubic pain?
Distal 1/3 transverse colon to anal verge
Where does biliary tract pain refer to?
Right inferior scapular area
Where does diaphragmatic irritation refer to?
Ipsilateral shoulder tip pain
Categorise the types of intra-abdominal causes of abdominal pain
- Generalised peritonitis
- Localised peritonitis
- Motility disorders
- Ischaemia
- Ruptured AAA
Categorise the types of extra-abdominal causes of abdominal pain
- Thoracic
- Neurological disease
- Metabolic
- Toxins
Name two causes of generalised peritonitis ➔ abdominal pain
- Perforated viscus
- Primary infectious peritonitis
- Rupture of cyst
Name 2 causes of localised peritonitis ➔ abdominal pain
- Appendicitis
- Cholecystitis
- Pancreatitis
- Diverticulitis
- Abscess
- Salpingitis/ruptured ectopic
Name 2 motility disorders causing abdominal pain
- Obstruction - intestinal, ureteric, biliary
- Spasm - irritable colon, uterine contraction
Name 2 ischaemic causes of abdominal pain
- Mesenteric angina (chronic)
- Splenic infarction
- Torsion - testicle, ovarian cyst, omentum
- Tumour necrosis - hepatoma, fibroid
Name 2 thoracic causes of abdominal pain
- Lung disease
- Ischaemic heart disease
- Oesophageal disease
Name 1 neurological cause of abdominal pain
- Shingles (Herpes zoster)
- Spinal arthritis
- Abdominal epilepsy (Seizures ➔ abdominal symptoms)
Name 2 metabolic causes of abdominal pain
- Diabetes mellitus (Gastroparesis: delayed emptying. Commoner in T1DM)
- Chronic renal failure
- Porphyria (Porphyrin accumulation)
- Acute adrenal insufficiency
Name 2 toxin causes of abdominal pain
- Snake and insect bites
- Lead poisoning
- Strychnine (pesticide)
- Peptic ulcer (H. pylori)
- Inflammatory disease
Name 4 differential diagnoses for acute abdominal pain
- Nonspecific
- Acute appendicitis
- Acute cholecystitis and biliary colic
- Peptic ulcer perforation
- Small bowel obstruction
- Gynaecological disease
- Acute pancreatitis
What features are suggestive of abdominal malignancy?
- Intermittent pain of 48+hr
- Altered bowel habit
- Abdominal distension
- Mass
- Weight loss
What features are suggestive of bowel obstruction?
- Colicky severe pain
- No aggravating factors
- Vomiting and constipation
- Previous surgery
- Abdominal distension
- High pitched tinkling bowel sounds
What features are suggesting of a perforated viscus?
- Sudden onset of pain
- Constant severe pain
- Pain aggravated by movement, coughing, sneezing
- Diffuse tenderness
- Silent rigid abdomen
N.B. This slightly raises serum amylase
Which bedside investigations may be done in acute abdomen, and why?
- BM (DKA)
- Urinalysis
- Pregnancy test*
- ECG (exclude MI, and necessary for anaesthetic)
What laboratory investigations may be done in acute abdomen, and why?
- FBC (infection, rarely diagnostic)
- U&Es
- Serum amylase* (3x normal max ➔ acute pancreatitis)
- LFTs
- ABGs
- CRP
What radiological investigations may be done in acute abdomen and, why?
- AXR - rarely diagnostic
- Erect CXR*: pneumoperitoneum
- Upper abdo USS: assess hepatobiliary pathology
- Pelvic USS: tubo-ovarian disease
- Contrast studies
- Endoscopy
- Abdominal CT: best Ix for generalised peritonitis
- MRI
CT and MRI are not routine due to significant radiation.
Outline the general management of acute abdomen
NBM Fluid balance: IV fluids + Catheter/NG tube Analgesia + antiemetic Observations Avoid ABX until a clear diagnosis is formed Treat underlying cause once management plan established.
What radiological finding suggests viscus perforation?
Air under the diaphragm in an erect CXR
Name 3 causes of acute abdomen that are surgical emergencies?
- Generalised peritonitis (except acute pancreatitis)
- Intestinal obstruction
- Acute mesenteric ischaemia
- Viscus perforation
- Strangulated (irreducible, tender) hernia
Name 3 causes of acute abdominal pain in Right hypochondriac region
- Right lower lobe pneumonia/embolism
- Cholecystitis
- Biliary colic
- Hepatitis
Name 3 causes of acute abdominal pain in Epigastric region
