Medical Articles

Acute Abdomen

Definition

  • Way: Any sudden non traumatic condition with it’s main manifestation in the abdomen where urgent surgery may be necessary.
  • Maingot: Acute abdominal pain present for less than 8 hours
  • In Practice: Abdominal signs that are interpreted by a clinician to require urgent laparotomy after medical causes for the abdominal pain are excluded

Approach

  • History and examination
  • Side room, blood and imaging investigations
  • In equivical cases serial examinations every 4 – 6 hours may be an alternative

Etiology

1) Inflammation/Infection

  • Peritoneum - Primary or secondary peritonitis, intra-abdominal abscess
  • Hollow organ
  • Solid organs
  • Mesenteric lymphadenitis
  • Pelvic organs

2) Mechanical (Obstruction/Acute distension)

  • Hollow organs
  • Solid
  • Mesenteric
  • Pelvic organs

3) Vascular

  • Intraperitoneal bleeding
  • Ischemia

4) Diverse

Gynaecological causes

  • Ectopic pregnancy
  • ASO
  • Torsion ,bleeding, rupture of ovarial cyst or tumour
  • Complications of pregnancy

Etiology – Extra-peritoneal

  • Pancreas
  • Urinary tract
  • Vascular
  • Retro-peritoneal bleeding/tumour

Etiology – Extra-abdominal

Medical causes

These include:

  • Cardiovascular
  • Respiratory
  • Musculo-skeletal
  • CNS
  • Metabolic/toxins
  • Hematological
  • Autoimmune
  • Systemic infection
  • Psychogenic

History

  • Site
  • Spread
  • Origin and progression
  • Nature of pain
  • Relieving and precipitating factors
  • Associated symptoms
  • Pain may be visceral, parietal, referred or a progression of one to the other

Visceral pain

  • Afferent C-fibers (unmielinated)
  • Distension, inflammation, ischaemia and direct infiltration
  • Character: Slow origin, dull, poorly localised, midline
  • Localised to Epigastrium Periumbilical
  • Lower abdomen

Parietal pain

  • C and A-delta fibers
  • Acute
  • Sharp
  • Better localized (Unilateral)
  • Direct irritation of somatic innervated parietal peritoneum

Referred pain

Confluence of afferent fibers from different areas in posterior horn of spinal cord

Examples

  • Right shoulder - diaphragm, gallbladder, liver capsule, right pleura/lung
  • Left shoulder - diaphragm, spleen, pancreas tail, stomach, splenic flexure, left pleura and lung

Referred pain

Examples cont.

  • Right scapula - gallbladder, bile ducts
  • left scapula – spleen, pancreas tail
  • Groin and genitalia - kidney, ureter, aorta iliac arteries
  • Midline back - pancreas , duodenum aorta

Spread

  • “Shifting” - pain initially visceral now parietal as in appendicitis
  • Referred pain can also be interpreted as spread

History - Abdominal Pain

  • Origin and progression: Sudden, rapid progression or slow progression
  • Nature: Intensity, periodicity
  • Constant sharp as in peritonitis
  • Colic – Cramps that come and go as in bowel obstruction, urinary tract, biliary tract
  • Relieving/precipitating factors

History - Associated symptoms

  • Nonspecific
  • Vomiting : Surgical cause - pain usually first
  • Medical- Vomiting usually first
  • Nature of vomiting, reflex or spontaneous
  • Constipation : Reflex or pain vs. obstipation
  • Diarrhea : Watery - Gastroenteritis Bloody - Colitis

History - Continued

  • Menstrual and genito-urinary
  • Medication
  • Family
  • Travel 
  • Previous medical and surgical history
  • Systemic history : Fever, rigors, weightloss, cardiorespiratory etc.

Examination

  • General and systemic: Attempt to differentiate medical and surgical cause
  • General examination
    • Roll around? Colic (Visceral pain)
    • Lie still? Peritonitis (Parietal pain)
    • Signs of intra-abdominal bleeding (AAA, ectopic pregnancy)
    • Systemic: Fever, tachipnoea, tachicardia blood pressure

Abdominal examination: Observe

  • Distension obstruction
    • Bleeding
    • Ascites
    • Pregnant
    • Tumour
  • Visible peristalses Obstruction
  • Scaphoid Diaphragmatic hernia

Abdominal examination: Palpate

  • Tenderness, muscle rigidity, masses Muscle rigidity “guarding” Conscious – Relaxes with deep inspiration Unconscious - “boardlike”
  • Localised tenderness indicative of pathology
  • Diffuse tenderness without peritonitis

Abdominal examination

  • Auscultate Peristaltic “rushes” Obstruction Silent peritonitis Late obstruction or peritonitis
  • Percussion
  • Tender - Peritonitis (Parietal)
  • Absent liver dullness - Perforated viscus
  • Shifting dullness - Free fluid

Abdominal examination

  • Maneuvers Psoas – tenderness on passive extension of hip Obturator - IR/ER Flexed hip Murphy’s sign Costovertebral angle punch tenderness - Pyelonephritis
  • Hernial orifices, Rectal examination
  • Genitalia - PV, Testis

Side room

  • Urine - Dipstix leucocyte ,nitrite, blood
    • Microscopy : cylinders
    • Pregnancy test
    • Stool
  • Occult blood, Rectal scrapings
  • Warm - Ova, parasites, amoeba, bacteria
  • Culture - Dysentery cholera

Laboratory

  • Individualize
  • FBC - WCC, CRP, ESR
  • Clotting, peripheral smear
  • U/E - Hydration, Kidney failure
  • Blood gas - acidosis with dead bowel
  • Serum en urine amylase or lipase
  • LFT
  • Culture urine, stool, blood
  • Watson-Schwartz Porphyria

Imaging

  • Erect CXR – Free air, Elevation of the diaphragm, pneumonia
  • Abdominal – Erect and supine
  • Bony elements
  • Bowel gas pattern Obstruction or ileus
  • Soft tissue - psoas shadow
  • Calcification - Gallstones, kidney stones, faecolith, chronic pancreatitis, AAA
  • Hernial orifices
  • Abnormal air i.e.. Bile ducts

Imaging

  • Sonar/CT : Upper abdominal pain? Biliary tract/liver Abscess or mass
  • Angiography – rare investigation AMI
  • Contrast studies - seldom Perforation i.e. oesophagus water soluble Single contrast barium enema in Colon obstruction/volvulus

Imaging

  • Nuclear Medicine i.e. HIDA scan
  • Endoscopy Sigmoidoscopy – colon obstruction Volvulus Upper GIT endoscopy i.e. Peptic ulcer ERCP i.e. choledocholithiasis
  • Parasintesis - evaluate fluid
  • Laparoscopy especially in females of child bearing age with possible appendicitis

Guidelines

  • Surgery: Abdominal pain for more than 6 hours, well localised
  • Acute appendicitis always high on the differential
  • Gynecological problems oftenthe cause in yong women
  • High index of suspicion for bowel ischaemia
  • Medical causes especially pneumonia and MI

Guidelines

  • Nonspecific abdominal pain common - consider close observation
  • Differentiate cause by taking location into account
  • Acute abdomen
  • Exclude extraperitoneal causes
  • Exclude pancreatitis
  • Laparotomy or laparoscopy