Acute abdomen
Prof. M K Alam M S ; F R C S
Learning objectives
 Definition of acute abdomen
 Anatomy and physiology of abdominal pain.
 Pathophysiology of common causes of acute abdomen.
 Symptoms and signs of acute abdomen in relation to
the underlying pathology
 Laboratory and imaging investigations
 Initial and definitive management
Definition
Acute abdomen
A clinical presentation of
abdominal pain and tenderness,
that often requires emergency
surgical therapy.
• Some non-surgical or non intra-abdominal
diseases, can present as an acute abdomen.
• A correct diagnosis so important for an
appropriate therapy.
Anatomy and Physiology
of
Abdominal pain
Types of abdominal pain
• Visceral
• Parietal
Visceral pain
• Vague, poorly localized ( patient directs with full hand)
• Splanchnic nerves
• Usually the result of distention of a hollow viscus
• Depending on the origin of the affected organ from the
primitive foregut, midgut, or hindgut, the pain is localized to
epigastrium, periumbilical , or hypogastrium respectively
Parietal pain
-Corresponds to the segmental nerve roots
(somatic nervous system) innervating the
peritoneum.
-Sharper and better localized.
Referred pain
Definition:
Pain perceived at a site distant from
the source of stimulus.
Common examples of referred pain:
Right shoulder- Gall bladder
Left shoulder- Heart, tail of pancreas, spleen (Kehr's sign)
Scrotum and testis- ureter
Pain location according to organs
(Great degree of overlap)
• Right hypochondrium.- gallbladder
• Left hypochondrium.- pancreas
• Epigastrium.- Stomach and duodenum
• Lumber- kidney
• Umbilical- small bowel, caecum, retroperitoneal
• Right iliac fossa- Appendix, caecum
• Left iliac fossa- Sigmoid colon
• Hypogastrium- Colon, urinary bladder, adenexae
Pain location in
common acute abdominal conditions
• Right hypochondrium: Acute cholecystitis, Hepatitis
• Epigastrium: Acute pancreatitis, Perforated duodenal ulcer
• Left hypochondrium: Splenic infarction, acute pancreatitis
• Right lower quadrant: Ac. Appendicitis, Crohn’s disease
Ectopic pregnancy, mid-cycle pain- female
• Left lower quadrant: Diverticulitis
• Periumbilical: appendicitis (initial), small bowel obstruction
• Lumber (flank): pyelonephritis, renal colic
• Hypogastrium: Colonic obstruction
Pathophysiology
Surgical Acute Abdominal Conditions
• Infection- Appendicitis, cholecystitis
• Perforation- Perforated duodenal ulcer
• Obstruction- Small bowel adhesions, obstructed hernia,
sigmoid volvulus
• Ischemia- Mesenteric ischemia (thrombosis/ embolism)
strangulated hernia
• Hemorrhage- Ruptured ectopic pregnancy, ruptured
aneurysm, solid organ trauma
Nonsurgical Causes of Acute
Abdomen
• Diabetic crisis
• Uremia
• Hereditary Mediterranean fever
• Sickle cell crisis
• Acute leukemia
Pathophysiology: Acute appendicitis
• Most common general surgical emergency
• Derived from the midgut
• Obstruction of the lumen (fecalith, lymphoid hyperplasia,
vegetable matter or seeds, parasites) is
the major cause of
acute appendicitis.
• Obstruction contributes to bacterial overgrowth,
Pathophysiology: Acute appendicitis
• Continued secretion of mucus leads to intraluminal distention.
• Distention produces the visceral pain sensation as
periumbilical pain.
• Promote a localized inflammatory process
• May progress to gangrene and perforation.
• Inflammation of the adjacent peritoneum- localized pain in the
right lower quadrant.
• Perforation usually occurs after 48 hours from the onset of
symptoms
Bacterial flora in appendicitis
• Polymicrobial nature of perforated
appendicitis.
• Escherichia coli, Streptococcus viridans, and
Bacteroides and Pseudomonas
Part II
Pathophysiology: Perforated peptic
ulcer
• 5% of peptic ulcers penetrate through the
duodenal wall into the peritoneal cavity
• Most common site: anterior wall of 1st part of
the duodenum
• Produce chemical peritonitis
Pathophysiology- peritonitis
• Introduction of bacteria or irritating chemicals
into the peritoneal cavity cause peritoneal
inflammation
• A localized inflammation (appendicitis) produce
sharply localized pain and normal bowel sounds
• A diffuse process (perforated viscus) produces
generalized peritonitis causing generalized
abdominal pain with a quiet abdomen
• Peritonitis is peritoneal inflammation
from any cause.
• Recognized by severe tenderness , with
or without rebound tenderness, and
guarding.
Types of peritonitis
• Secondary peritonitis: more common, secondary to an
inflammatory insult from within abdomen, most often gramnegative infections with enteric organisms or anaerobes.
Example- appendicitis
• Primary peritonitis: uncommon.
Children: Pneumococcus or hemolytic Streptococcus.
Adults: peritoneal dialysis for end-stage renal dis.(gram+ve cocci),
ascites and cirrhosis(Escherichia coli and Klebsiella)
• Noninfectious inflammation- pancreatitis (chemical peritonitis)
Pathophysiology: Small bowel obstruction
• Post-operative adhesion- most common
• Hernia, tumour, Crohn’s disease- other causes
• Early- the intestinal contraction increases to propel contents past
the obstructing point (colicky pain)
• Later- the intestine becomes fatigued and dilates, contractions
becoming less intense.
• Bowel dilates, water and electrolytes accumulate in lumen and in
the bowel wall.
• Massive third-space fluid loss: dehydration and hypovolemia.
• Intraluminal pressure increases in the bowel, a decrease in mucosal
blood flow occurs.
Pathophysiology: Mesenteric Ischemia
• Arterial: embolism, thrombosis
• Venous: thrombosis
• Superior mesenteric vessel distribution
• Intestinal mucosal sloughing within 3 hours of
onset
• Full-thickness intestinal infarction by 6 hours
Symptoms & Signs
in
Acute abdomen
Main symptom- Abdominal pain
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Location: finger vs hand (visceral)
Severity:
Onset: sudden in perforation, ischemia, biliary colic
Progress: develops and worsens over several hours is
typical of progressive inflammation or infection such as
appendicitis, cholecystitis
Spasmodic: Biliary colic, or genitourinary obstruction
Radiation and shift: cholecystitis, appendicitis
Exacerbating factors: food worsen pain of bowel
obstruction
Relieving factors: food relieves pain of non-perforated
peptic ulcer disease or gastritis.
Associated symptoms
• Vomiting likely to precede significant abdominal pain in medical
conditions whereas pain presents first in acute surgical abdomen.
• Constipation or obstipation can be a result of either mechanical
obstruction or decreased peristalsis (ileus).
• Diarrhea is associated with several medical causes of acute
abdomen, including infectious enteritis, inflammatory bowel
disease (IBD), and parasitic contamination
• Bloody diarrhea- IBD, Colonic ischemia
• Past medical history: passage of stone(ureteric colic)
previous surgery (intestinal obstruction)
• Gynecologic history: LMP (ectopic pregnancy),
mid cycle pain (mittelschmerz)
• Medications: create acute abdominal conditions or
mask their symptoms. NSAID (bleeding, perforation),
narcotics (constipation), steroids (mask inflammation)
PHYSICAL EXAMINATION
(Inspection)
• Inspection of the patient:
• Ischemic bowel and ureteral and biliary colic, typically cause
patients to continually shift and fidget in bed while trying to find a
position that lessens their discomfort.
• Patients with peritonitis lie very still in the bed during the
evaluation and often maintain flexion of their knees and hips to
reduce tension on the anterior abdominal wall.
Inspection of the abdomen
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Distension
Restricted mobility- ?peritonitis
Scars of previous surgery
Hernias
Mass effect
Ecchymosis ? Acute pancreatitis (Cullen’s, Grey
Turner’s sign)
Palpation of the abdomen
• Start gently, away from the area of pain.
• Severity and exact location of tendernesslocalized/ generalized
• Involuntary guarding
• Organomegaly, mass
• Murphy’s sign, Rovsing’s sign,
• Rebound tenderness (Blumberg’s sign)
Percussion of the abdomen
• Hyperresonance :distended bowel loops
• Dullness due to organomegaly or mass
• Liver dullness lost- free intra-abdominal air is suspected.
• Shifting dullness
• Tenderness
Auscultation of the abdomen
• Quiet abdomen- ileus
• Hyperactive bowel sounds- enteritis, ischemic
intestine
• Mechanical bowel obstruction- high-pitched
“tinkling” sounds that come in rushes and are
associated with pain
• Bruits- high-grade arterial stenosis
Digital rectal examination
• Performed in all patients with acute
abdominal pain
• Checking for mass, pelvic pain, or intraluminal
blood
• Pelvic examination in female
Part III
Investigations
Routine laboratory investigations
• Hematology: WBC count, differential count, hemoglobin,
platelets, red blood cells
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Electrolytes, urea, creatinine
Amylase, lipase
LFTs: Bilirubin (T & D), alkaline phosphatase, aminotransferase,
Serum lactate & arterial blood gas
Urine analysis
Urine human chorionic gonadotropin
Stool for parasites
• WBC count: confirm infection
• Electrolytes, blood urea nitrogen, and creatinine: the effect
of vomiting or third-space fluid losses
• Serum amylase and lipase- acute pancreatitis (high level),
small bowel infarction or duodenal ulcer perforation (mild to
moderate rise)
• Liver function tests: biliary tract
disease.
• Lactate levels and arterial blood gas:
intestinal
ischemia or infarction.
• Urinalysis: bacterial cystitis, pyelonephritis, diabetes.
• Urinary human chorionic gonadotropin: suggest
pregnancy as a factor in the patient's presentation or aid in
decision making regarding therapy.
• Stool: occult blood, parasite, Cl. Difficile (toxin & culture).
Imaging studies
None of the imaging techniques take the
place of a careful history and physical
examination.
Plain radiographs
• Upright chest radiographs – free gas under
the dome of diaphragm
Perforated duodenal ulcer-75%
• Lateral decubitus abdominal radiographspneumoperitoneum in patients who cannot
stand
Plain x-ray abdomen
• Calcifications: renal stones 90%, chronic
pancreatic, aortic aneurysms, fecalith
• Supine and upright films: distension, fluid levels,
gas distribution (small vs large bowel), volvulus
of sigmoid colon/ cecum
Abdominal ultrasonography
• Gallbladder: stone, wall thickness, fluid around
gallbladder, diameter of bile ducts
• Liver: abscess, other masses
• Pelvis: Ovarian, adnexal & uterine pathologies
• Free fluid in peritoneum
• Limited evaluation of pancreas
• Limitations: bowel gas, person dependent, difficult
to interpret for most surgeons
CT abdomen
• Widely available
• Easier to interpret by surgeons
• Imaging modality of choice in acute abdomen,
following plain abdominal radiographs.
• Accuracy and utility of CT abdomen and pelvis
in acute abdominal pain is well established.
• Most common causes of acute abdomen are
readily identified by CT
• Highly accurate in acute appendicitis,
mechanical bowel obstruction, intestinal
ischemia
DIAGNOSTIC LAPAROSCOPY
• Ability to diagnose and treat a number of the
conditions causing an acute abdomen
• High sensitivity and specificity
• Decreased morbidity and mortality, decreased
length of stay, and decreased overall hospital costs
• Advances in equipment and greater availability
DIFFERENTIAL DIAGNOSIS
• Differential diagnosis of acute abdominal pain is extensive.
• Comprehensive knowledge of the medical and surgical
conditions that create acute abdominal pain
• Mild, self-limited illness to the rapidly progressive and fatal
• Evaluated immediately upon presentation and reassessed at
frequent intervals.
• Many acute abdomen require surgical intervention but some
abdominal pain are medical in aetiology.
Part IV
Initial management
Preoperative preparation
• Fluid and electrolyte abnormalities corrected
• Antibiotic infusions for the bacteria common in acute
abdominal emergencies (gram-negative enteric organisms and
anaerobes)
• Nasogastric tube to decrease the likelihood of vomiting
and aspiration
• Foley catheter- to assess urine output -0.5 mL/kg/hour
• Blood typed and cross matched for operation
Preoperative preparation
• Frequent evaluation of the patient
• Stabilization of co-morbid conditions
• Surgical vs non- surgical management
• Consent for surgery
Common Causes
of
Acute Abdomen
Acute appendicitis
• Most common general surgical emergency
• Derived from the midgut
• Obstruction of the lumen (fecalith, lymphoid hyperplasia,
vegetable matter or seeds, parasites) is
the major cause of
acute appendicitis.
• Obstruction contributes to bacterial overgrowth,
Acute appendicitis
• Continued secretion of mucus leads to intraluminal distention.
• Distention produces the visceral pain sensation as
periumbilical pain.
• Promote a localized inflammatory process
• May progress to gangrene and perforation.
• Inflammation of the adjacent peritoneum- localized pain in the
right lower quadrant.
• Perforation usually occurs after 48 hours from the onset of
symptoms
Acute appendicitis- symptoms
• Typical periumbilical pain (activation of visceral afferent neurons)
followed by anorexia and nausea.
• Pain localizes to the right lower quadrant (inflammatory process
progresses to involve the parietal peritoneum)
• Migratory pain is the most reliable symptom.
Acute appendicitis- signs
• Ill looking patient, low grade fever
• Coughing may cause increased pain (Dunphy's sign)
• Tenderness at McBurney’s point, involuntary guarding
• Site of tenderness may vary depending on the position of the
appendix.
• Pain felt in the right lower quadrant during palpation of the left
lower quadrant (Rovsing's sign)
• Perforated appendicitis: more severe and diffuse abdominal pain,
tenderness and abdominal wall rigidity
Acute appendicitis- investigations
• Elevated WBC and neutrophil
• Normal WBC in 10%
• Very high WBC (>20,000/ml)- complicated appendicitis
• Urine analysis- exclude urinary system disease
• Abdominal x-ray- generally not indicated,
? ureteric calculi, small bowel obstruction, perforated ulcer
• Ultrasonography: appendix of 7 mm or more in anteroposterior
diameter, thick-walled, noncompressible luminal structure in cross
section (target lesion), the presence of an appendicolith
• CT abdomen: appendix > 7mm in diameter, wall thickening,
periappendiceal edema or fluid
Surgical treatment (Acute appendicitis)
• Uncomplicated appendicitis:
Appendectomy - Laparoscopic vs open surgery
• Complicated appendicitis:
Localized perforation (abscess): percutaneous
drainage under CT or ultrasound guidance
Free perforation (peritonitis): laparotomy vs
laparoscopic appendectomy
Part V
Perforated peptic ulcer
• 5% of peptic ulcers penetrate through the
duodenal wall into the peritoneal cavity
• Produce chemical peritonitis
Clinical features of perforated peptic ulcer
• Sudden onset epigastric pain
• Fever and tachycardia
• Abdominal tenderness, rigidity, rebound
tenderness
• Absent bowel sound
• Free air underneath the diaphragm on an
upright chest radiograph.
Perforated peptic ulcer- treatment
• Fluid resuscitation
• Early surgery to close the perforation by
laparoscopy or open surgery
Small bowel obstruction
• Post-operative adhesion- most common
• Hernia, tumour, Crohn’s disease- other causes
• Early- the intestinal contraction increases to propel contents past
the obstructing point (colicky pain)
• Later- the intestine becomes fatigued and dilates, contractions
becoming less intense.
• Bowel dilates, water and electrolytes accumulate in lumen and in
the bowel wall.
• Massive third-space fluid loss: dehydration and hypovolemia.
• Intraluminal pressure increases in the bowel, a decrease in mucosal
blood flow occurs.
Clinical features
• Colicky abdominal pain, nausea, vomiting,
abdominal distention, and a failure to pass flatus
and feces (i.e., obstipation).
• Examination:
Distended abdomen
Surgical scars/ hernia
Hyperactive bowel sounds
Mild abdominal tenderness
Investigations
• Tests for fluid & electrolytes abnormality
• Leukocytosis may be found in patients with
strangulation
• Plain x-ray abdomen: dilated bowel loops (supine)
& multiple air-fluid levels (upright)
• Patient in whom the diagnosis is not readily
apparent- CT abdomen
Treatment
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Isotonic saline solution such as lactated Ringer's
Antibiotics-prophylactically
Nasogastric suction
Partial intestinal obstruction may be treated
conservatively with resuscitation and tube
decompression
• Operative Management:
• Adhesive obst.-laparotomy & release of adhesions.
• Hernia- operative reduction and repair
Mesenteric Ischemia
• Arterial: embolism, thrombosis
• Venous: thrombosis
• Superior mesenteric vessel distribution
• Intestinal mucosal sloughing within 3 hours of
onset and
• Full-thickness intestinal infarction by 6 hours
Symptoms & signs
• Abdominal pain- sudden onset
• Severity- out of proportion to the degree of tenderness
• The pain is colicky, most severe in the mid-abdomen.
• Associated symptoms- nausea, vomiting, and diarrhea
• Physical findings- absent early in the course.
• Later- abdominal distention, tenderness, guarding and
passage of bloody stools.
Investigations
• Leukocytosis,
• Acidosis, and
• Elevated amylase and creatine kinase- late
• CT scanning:
Acute arterial mesenteric ischemia-64 to 82%.
Acute mesenteric venous thrombosis- 90%
Mesenteric ischemia- treatment
• Fluid resuscitation
• Laparotomy
• Test for viability of bowel
• Resection of infarcted segment
• Anticoagulation for SMV thrombosis
Conclusion
• A challenging part of a surgeon's practice.
• Careful history and physical examination remain the
most important part of the evaluation.
• Laboratory investigations and imaging techniques have
improved the diagnostic accuracy
• Surgeon often make the decision to perform surgery
with a good deal of uncertainty
• Morbidity and mortality associated with a delay in the
treatment demand an expeditious approach
Thank you!
Part VI
Case presentation
Case No. 1
A 19-year old male presents with abdominal pain
since last night. He has vomited once early this
morning.
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History
Examination
Differential diagnosis
Investigations
Pathophysiology
Complications of delayed presentation/ treatment
Treatment
History
• Location: Initially periumbilical, now RIF
• Severity: started mild, now severe
• Onset: gradual
• Progress: worsening
• Radiation and shift: Initially periumbilical, now RIF
• Exacerbating factors: none
• Relieving factors: none
• Associated symptoms: vomiting once, no anorexia
• Systemic inquiry, family, social, drug, past history- none
Examination
• Appearance: Looking ill
• Temperature: 38.5°C
• Abdomen: Inspection- flat, moving with
respiration, no cough tenderness
• Palpation- guarding & tenderness in RIF and at
McBurney’s point, Rovsing’s sign –ve
• Percussion- tender RIF
• Auscultation- diminished bowel sounds
• Rectal examination not done
Differential diagnosis
• Children: Meckel’s diverticulitis, intussusception,
gastroenteritis, mesenteric lymphadenitis
• Adults: Crohn’s disease, pyelonephritis,
ileo-cecal neoplasm, bowel obstruction
• Female: Ectopic pregnancy, mid cycle pain,
tubo-ovarian pathology, PID
Acute appendicitis
Investigations
• Leucocytosis with high neutrophil
• Very high WBC > 20,000 in complicated app.
• Urinalysis to rule out urinary infection
• Ultrasonography: Not done. Indicated in
children and pregnant. Thick wall, noncompressible, edema and fluid
• CT: Not done. Distended, thick wall
periappendiceal edema and fluid
Pathophysiology
• Obstruction of the lumen
• Fecalith, lymphoid hyperplasia, vegetable, seeds, parasites,
neoplasm
• Small lumen, obstruction lead to closed loop
• Bacterial overgrowth
• Continued mucous secretion lead to distension and typical
visceral pain in periumbilical area
• Inflammation of adjacent parietal peritoneum gives rise to
localized RIF (parietal) pain
Delayed presentation
• Inflammatory progress to gangrene
• Localized perforation- abscess formation
• Free perforation- peritonitis (secondary)
Treatment
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Nil orally
IV fluid
Pre-op. antibiotics: cefuroxime+ metronidazole
Non-perforated: single pre-op. dose
Perforated: continue post-op. until afebrile
Consent for surgery
Appendectomy- laparoscopic or open surgery
Appendicular abscess- image guided drainage
Free perforation- Open/ laparoscopic appendectomy
Case No. 2
A 30-year old female presents with right
hypochondrial pain for 2 days associated with
fever.
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History
Examination
Differential diagnosis
Investigations
Pathophysiology
Management
History
• Location: right hypochondrium
• Severity: started mild, now severe
• Onset: gradual
• Progress: worsening
• Radiation: back and right shoulder
• Exacerbating factors: fatty food
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Relieving factors: analgesics
• Associated symptoms: fever, no vomiting , no anorexia
• Systemic inquiry, family, social, drug history- none
• Past medical history- similar pain of shorter duration 2 months back
Examination
• Appearance: In pain
• Temp. 38.6°C
• No jaundice
• Abdomen: Inspection- normal, few striae gravidarum
• Palpation- tenderness & guarding in RH,
Murphy’s sign +ve ( tenderness & arrest of inspiration
while palpating at costal margin)
• Percussion, auscultation- none
Differential diagnosis
• Chronic cholecystitis
• Biliary colic
• Obstructive jaundice
• Liver abscess
• Viral hepatitis
Acute cholecystitis
Investigations
• Leucocytosis
• LFT: very slight elevation of bilirubin, normal
alkaline phosphatase and transaminase
• Abdominal ultrasonography: gall stones, gall
bladder wall thickening, edema,
pericholecystic fluid
Pathophysiology
• Obstruction of the cystic duct
• Bacterial inflammation
• If obstruction persists- ischemia and gangrene
of the gall bladder
• Eventually perforation
Management
• Nil by mouth
• IV fluid
• Parenteral antibiotics- (gram –ve and gram +ve
organisms)- cephalosporin
• Consent for surgery
• Early laparoscopic cholecystectomy
Thank you!