2. Acute abdomen
Prof. M K Alam M S ; F R C S

3. 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

4. Definition
Acute abdomen A clinical presentation of abdominal pain and tenderness, that often requires emergency surgical therapy.

5. Some non-surgical or non intra-abdominal diseases, can present as an acute abdomen.
A correct diagnosis so important for an appropriate therapy.

6. Anatomy and Physiology of Abdominal pain

7. Types of abdominal pain
Visceral
Parietal

8. 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

9. Parietal pain
-Corresponds to the segmental nerve roots (somatic nervous system) innervating the peritoneum.
-Sharper and better localized.

10. 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

11. 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

13. 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

14. Pathophysiology

15. 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

16. Nonsurgical Causes of Acute Abdomen
Diabetic crisis
Uremia
Hereditary Mediterranean fever
Sickle cell crisis
Acute leukemia

17. 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,

18. 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

19. Bacterial flora in appendicitis
Polymicrobial nature of perforated appendicitis.
Escherichia coli, Streptococcus viridans, and Bacteroides and Pseudomonas

20. Part II

21. 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

22. 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

23. Peritonitis is peritoneal inflammation from any cause.
Recognized by severe tenderness , with or without rebound tenderness, and guarding.

24. Types of peritonitis
Secondary peritonitis: more common, secondary to an inflammatory insult from within abdomen, most often gram-negative 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)

25. 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.

26. 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

27. Symptoms & Signs in Acute abdomen

28. Main symptom- Abdominal pain
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.

29. 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

30. 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)

31. 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.

32. Inspection of the abdomen
Distension
Restricted mobility- ?peritonitis
Scars of previous surgery
Hernias
Mass effect
Ecchymosis ? Acute pancreatitis (Cullen’s, Grey Turner’s sign)

33. Palpation of the abdomen
Start gently, away from the area of pain.
Severity and exact location of tenderness- localized/ generalized
Involuntary guarding
Organomegaly, mass
Murphy’s sign, Rovsing’s sign,
Rebound tenderness (Blumberg’s sign)

34. 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

35. 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

36. Digital rectal examination
Performed in all patients with acute abdominal pain
Checking for mass, pelvic pain, or intraluminal blood
Pelvic examination in female

37. Part III

38. Investigations

39. Routine laboratory investigations
Hematology: WBC count, differential count, hemoglobin, platelets, red blood cells
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

40. 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.

41. 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).

42. Imaging studies
None of the imaging techniques take the place of a careful history and physical examination.

43. Plain radiographs
Upright chest radiographs – free gas under the dome of diaphragm Perforated duodenal ulcer-75%
Lateral decubitus abdominal radiographs- pneumoperitoneum in patients who cannot stand

45. 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

49. 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

51. 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

53. 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

54. 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.

57. Part IV

58. Initial management

59. 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

60. Preoperative preparation
Frequent evaluation of the patient
Stabilization of co-morbid conditions
Surgical vs non- surgical management
Consent for surgery

61. Common Causes of Acute Abdomen

62. 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,

63. 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

64. 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.

65. 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

66. 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

68. 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

70. Part V

71. Perforated peptic ulcer
5% of peptic ulcers penetrate through the duodenal wall into the peritoneal cavity
Produce chemical peritonitis

72. 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.

74. Perforated peptic ulcer- treatment
Fluid resuscitation
Early surgery to close the perforation by laparoscopy or open surgery

75. 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.

76. 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

77. 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

78. Treatment 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

79. 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

80. 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.

81. Investigations Leukocytosis, Acidosis, and
Elevated amylase and creatine kinase- late
CT scanning:
Acute arterial mesenteric ischemia-64 to 82%.
Acute mesenteric venous thrombosis- 90%

83. Mesenteric ischemia- treatment
Fluid resuscitation
Laparotomy
Test for viability of bowel
Resection of infarcted segment
Anticoagulation for SMV thrombosis

85. 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

86. Thank you!

87. Part VI

88. Case presentation

89. Case No. 1
A 19-year old male presents with abdominal pain since last night. He has vomited once early this morning.
History
Examination
Differential diagnosis
Investigations
Pathophysiology
Complications of delayed presentation/ treatment
Treatment

90. 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

91. 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

92. 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

93. Acute appendicitis

94. 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, non-compressible, edema and fluid
CT: Not done. Distended, thick wall periappendiceal edema and fluid

95. 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

96. Delayed presentation Inflammatory progress to gangrene
Localized perforation- abscess formation
Free perforation- peritonitis (secondary)

97. Treatment 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

98. Case No. 2
A 30-year old female presents with right hypochondrial pain for 2 days associated with fever.
History
Examination
Differential diagnosis
Investigations
Pathophysiology
Management

99. History Location: right hypochondrium
Severity: started mild, now severe
Onset: gradual
Progress: worsening
Radiation: back and right shoulder
Exacerbating factors: fatty food
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

100. 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

101. Differential diagnosis
Chronic cholecystitis
Biliary colic
Obstructive jaundice
Liver abscess
Viral hepatitis

102. Acute cholecystitis

103. Investigations Leucocytosis
LFT: very slight elevation of bilirubin, normal alkaline phosphatase and transaminase
Abdominal ultrasonography: gall stones, gall bladder wall thickening, edema, pericholecystic fluid

104. Pathophysiology Obstruction of the cystic duct Bacterial inflammation
If obstruction persists- ischemia and gangrene of the gall bladder
Eventually perforation

105. Management Nil by mouth IV fluid
Parenteral antibiotics- (gram –ve and gram +ve organisms)- cephalosporin
Consent for surgery
Early laparoscopic cholecystectomy

106. Thank you!