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 • • • • • • • • 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 • • • • • • 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 • • • • • • • 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 • • • • 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. • • • • • • • 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 • • • • • • • • • 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. • • • • • • 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 • 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!