3Learning 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 pathologyLaboratory and imaging investigationsInitial and definitive management
4DefinitionAcute abdomen A clinical presentation of abdominal pain and tenderness, that often requires emergency surgical therapy.
5Some non-surgical or non intra-abdominal diseases, can present as an acute abdomen. A correct diagnosis so important for an appropriate therapy.
8Visceral painVague, poorly localized ( patient directs with full hand)Splanchnic nervesUsually the result of distention of a hollow viscusDepending on the origin of the affected organ from the primitive foregut, midgut, or hindgut, the pain is localized to epigastrium, periumbilical , or hypogastrium respectively
9Parietal pain-Corresponds to the segmental nerve roots (somatic nervous system) innervating the peritoneum.-Sharper and better localized.
10Referred painDefinition: Pain perceived at a site distant from the source of stimulus.Common examples of referred pain:Right shoulder- Gall bladderLeft shoulder- Heart, tail of pancreas, spleen (Kehr's sign)Scrotum and testis- ureter
11Pain location according to organs (Great degree of overlap) Right hypochondrium.- gallbladderLeft hypochondrium.- pancreasEpigastrium.- Stomach and duodenumLumber- kidneyUmbilical- small bowel, caecum, retroperitonealRight iliac fossa- Appendix, caecumLeft iliac fossa- Sigmoid colonHypogastrium- Colon, urinary bladder, adenexae
17Pathophysiology: Acute appendicitis Most common general surgical emergencyDerived from the midgutObstruction of the lumen (fecalith, lymphoid hyperplasia, vegetable matter or seeds, parasites) is the major cause of acute appendicitis.Obstruction contributes to bacterial overgrowth,
18Pathophysiology: Acute appendicitis Continued secretion of mucus leads to intraluminal distention.Distention produces the visceral pain sensation as periumbilical pain.Promote a localized inflammatory processMay 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
19Bacterial flora in appendicitis Polymicrobial nature of perforated appendicitis.Escherichia coli, Streptococcus viridans, and Bacteroides and Pseudomonas
21Pathophysiology: Perforated peptic ulcer 5% of peptic ulcers penetrate through the duodenal wall into the peritoneal cavityMost common site: anterior wall of 1st part of the duodenumProduce chemical peritonitis
22Pathophysiology- peritonitis Introduction of bacteria or irritating chemicals into the peritoneal cavity cause peritoneal inflammationA localized inflammation (appendicitis) produce sharply localized pain and normal bowel soundsA diffuse process (perforated viscus) produces generalized peritonitis causing generalized abdominal pain with a quiet abdomen
23Peritonitis is peritoneal inflammation from any cause. Recognized by severe tenderness , with or without rebound tenderness, and guarding.
24Types of peritonitisSecondary peritonitis: more common, secondary to an inflammatory insult from within abdomen, most often gram-negative infections with enteric organisms or anaerobes. Example- appendicitisPrimary 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)
25Pathophysiology: Small bowel obstruction Post-operative adhesion- most commonHernia, tumour, Crohn’s disease- other causesEarly- 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.
26Pathophysiology: Mesenteric Ischemia Arterial: embolism, thrombosisVenous: thrombosisSuperior mesenteric vessel distributionIntestinal mucosal sloughing within 3 hours of onsetFull-thickness intestinal infarction by 6 hours
28Main symptom- Abdominal pain Location: finger vs hand (visceral)Severity:Onset: sudden in perforation, ischemia, biliary colicProgress: develops and worsens over several hours is typical of progressive inflammation or infection such as appendicitis, cholecystitisSpasmodic: Biliary colic, or genitourinary obstructionRadiation and shift: cholecystitis, appendicitisExacerbating factors: food worsen pain of bowel obstructionRelieving factors: food relieves pain of non-perforated peptic ulcer disease or gastritis.
29Associated symptomsVomiting 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 contaminationBloody diarrhea- IBD, Colonic ischemia
30Past 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)
31PHYSICAL 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.
32Inspection of the abdomen DistensionRestricted mobility- ?peritonitisScars of previous surgeryHerniasMass effectEcchymosis ? Acute pancreatitis (Cullen’s, Grey Turner’s sign)
33Palpation of the abdomen Start gently, away from the area of pain.Severity and exact location of tenderness- localized/ generalizedInvoluntary guardingOrganomegaly, massMurphy’s sign, Rovsing’s sign,Rebound tenderness (Blumberg’s sign)
34Percussion of the abdomen Hyperresonance :distended bowel loopsDullness due to organomegaly or massLiver dullness lost- free intra-abdominal air is suspected.Shifting dullnessTenderness
35Auscultation of the abdomen Quiet abdomen- ileusHyperactive bowel sounds- enteritis, ischemic intestineMechanical bowel obstruction- high-pitched “tinkling” sounds that come in rushes and are associated with painBruits- high-grade arterial stenosis
36Digital rectal examination Performed in all patients with acute abdominal painChecking for mass, pelvic pain, or intraluminal bloodPelvic examination in female
40WBC count: confirm infection Electrolytes, blood urea nitrogen, and creatinine: the effect of vomiting or third-space fluid lossesSerum amylase and lipase- acute pancreatitis (high level), small bowel infarction or duodenal ulcer perforation (mild to moderate rise)Liver function tests: biliary tract disease.
41Lactate 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).
42Imaging studiesNone of the imaging techniques take the place of a careful history and physical examination.
43Plain radiographsUpright chest radiographs – free gas under the dome of diaphragm Perforated duodenal ulcer-75%Lateral decubitus abdominal radiographs- pneumoperitoneum in patients who cannot stand
45Plain x-ray abdomenCalcifications: renal stones 90%, chronic pancreatic, aortic aneurysms, fecalithSupine and upright films: distension, fluid levels, gas distribution (small vs large bowel), volvulus of sigmoid colon/ cecum
49Abdominal ultrasonography Gallbladder: stone, wall thickness, fluid around gallbladder, diameter of bile ductsLiver: abscess, other massesPelvis: Ovarian, adnexal & uterine pathologiesFree fluid in peritoneumLimited evaluation of pancreasLimitations: bowel gas, person dependent, difficult to interpret for most surgeons
51CT 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 CTHighly accurate in acute appendicitis, mechanical bowel obstruction, intestinal ischemia
53DIAGNOSTIC LAPAROSCOPY Ability to diagnose and treat a number of the conditions causing an acute abdomenHigh sensitivity and specificityDecreased morbidity and mortality, decreased length of stay, and decreased overall hospital costsAdvances in equipment and greater availability
54DIFFERENTIAL DIAGNOSIS Differential diagnosis of acute abdominal pain is extensive.Comprehensive knowledge of the medical and surgical conditions that create acute abdominal painMild, self-limited illness to the rapidly progressive and fatalEvaluated immediately upon presentation and reassessed at frequent intervals.Many acute abdomen require surgical intervention but some abdominal pain are medical in aetiology.
59Preoperative preparation Fluid and electrolyte abnormalities correctedAntibiotic infusions for the bacteria common in acute abdominal emergencies (gram-negative enteric organisms and anaerobes)Nasogastric tube to decrease the likelihood of vomiting and aspirationFoley catheter- to assess urine output -0.5 mL/kg/hourBlood typed and cross matched for operation
60Preoperative preparation Frequent evaluation of the patientStabilization of co-morbid conditionsSurgical vs non- surgical managementConsent for surgery
62Acute appendicitis Most common general surgical emergency Derived from the midgutObstruction of the lumen (fecalith, lymphoid hyperplasia, vegetable matter or seeds, parasites) is the major cause of acute appendicitis.Obstruction contributes to bacterial overgrowth,
63Acute appendicitisContinued secretion of mucus leads to intraluminal distention.Distention produces the visceral pain sensation as periumbilical pain.Promote a localized inflammatory processMay 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
64Acute 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.
65Acute appendicitis- signs Ill looking patient, low grade feverCoughing may cause increased pain (Dunphy's sign)Tenderness at McBurney’s point, involuntary guardingSite 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
66Acute appendicitis- investigations Elevated WBC and neutrophilNormal WBC in 10%Very high WBC (>20,000/ml)- complicated appendicitisUrine analysis- exclude urinary system diseaseAbdominal x-ray- generally not indicated, ? ureteric calculi, small bowel obstruction, perforated ulcerUltrasonography: appendix of 7 mm or more in anteroposterior diameter, thick-walled, noncompressible luminal structure in cross section (target lesion), the presence of an appendicolithCT abdomen: appendix > 7mm in diameter, wall thickening, periappendiceal edema or fluid
71Perforated peptic ulcer 5% of peptic ulcers penetrate through the duodenal wall into the peritoneal cavityProduce chemical peritonitis
72Clinical features of perforated peptic ulcer Sudden onset epigastric painFever and tachycardiaAbdominal tenderness, rigidity, rebound tendernessAbsent bowel soundFree air underneath the diaphragm on an upright chest radiograph.
74Perforated peptic ulcer- treatment Fluid resuscitationEarly surgery to close the perforation by laparoscopy or open surgery
75Small bowel obstruction Post-operative adhesion- most commonHernia, tumour, Crohn’s disease- other causesEarly- 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.
76Clinical featuresColicky abdominal pain, nausea, vomiting, abdominal distention, and a failure to pass flatus and feces (i.e., obstipation).Examination:Distended abdomenSurgical scars/ herniaHyperactive bowel soundsMild abdominal tenderness
77Investigations Tests for fluid & electrolytes abnormality Leukocytosis may be found in patients with strangulationPlain x-ray abdomen: dilated bowel loops (supine) & multiple air-fluid levels (upright)Patient in whom the diagnosis is not readily apparent- CT abdomen
78Treatment Isotonic saline solution such as lactated Ringer's Antibiotics-prophylacticallyNasogastric suctionPartial intestinal obstruction may be treated conservatively with resuscitation and tube decompressionOperative Management:Adhesive obst.-laparotomy & release of adhesions.Hernia- operative reduction and repair
79Mesenteric Ischemia Arterial: embolism, thrombosis Venous: thrombosis Superior mesenteric vessel distributionIntestinal mucosal sloughing within 3 hours of onset andFull-thickness intestinal infarction by 6 hours
80Symptoms & signs Abdominal pain- sudden onset Severity- out of proportion to the degree of tendernessThe pain is colicky, most severe in the mid-abdomen.Associated symptoms- nausea, vomiting, and diarrheaPhysical findings- absent early in the course.Later- abdominal distention, tenderness, guarding and passage of bloody stools.
81Investigations Leukocytosis, Acidosis, and Elevated amylase and creatine kinase- lateCT scanning:Acute arterial mesenteric ischemia-64 to 82%.Acute mesenteric venous thrombosis- 90%
85Conclusion 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 accuracySurgeon often make the decision to perform surgery with a good deal of uncertaintyMorbidity and mortality associated with a delay in the treatment demand an expeditious approach
89Case No. 1A 19-year old male presents with abdominal pain since last night. He has vomited once early this morning.HistoryExaminationDifferential diagnosisInvestigationsPathophysiologyComplications of delayed presentation/ treatmentTreatment
90History Location: Initially periumbilical, now RIF Severity: started mild, now severeOnset: gradualProgress: worseningRadiation and shift: Initially periumbilical, now RIFExacerbating factors: noneRelieving factors: noneAssociated symptoms: vomiting once, no anorexiaSystemic inquiry, family, social, drug, past history- none
91Examination Appearance: Looking ill Temperature: 38.5°C Abdomen: Inspection- flat, moving with respiration, no cough tendernessPalpation- guarding & tenderness in RIF and at McBurney’s point, Rovsing’s sign –vePercussion- tender RIFAuscultation- diminished bowel soundsRectal examination not done
94Investigations Leucocytosis with high neutrophil Very high WBC > 20,000 in complicated app.Urinalysis to rule out urinary infectionUltrasonography: Not done. Indicated in children and pregnant. Thick wall, non-compressible, edema and fluidCT: Not done. Distended, thick wall periappendiceal edema and fluid
95Pathophysiology Obstruction of the lumen Fecalith, lymphoid hyperplasia, vegetable, seeds, parasites, neoplasmSmall lumen, obstruction lead to closed loopBacterial overgrowthContinued mucous secretion lead to distension and typical visceral pain in periumbilical areaInflammation of adjacent parietal peritoneum gives rise to localized RIF (parietal) pain
97Treatment Nil orally IV fluid Pre-op. antibiotics: cefuroxime+ metronidazoleNon-perforated: single pre-op. dosePerforated: continue post-op. until afebrileConsent for surgeryAppendectomy- laparoscopic or open surgeryAppendicular abscess- image guided drainageFree perforation- Open/ laparoscopic appendectomy
98Case No. 2A 30-year old female presents with right hypochondrial pain for 2 days associated with fever.HistoryExaminationDifferential diagnosisInvestigationsPathophysiologyManagement
99History Location: right hypochondrium Severity: started mild, now severeOnset: gradualProgress: worseningRadiation: back and right shoulderExacerbating factors: fatty foodRelieving factors: analgesicsAssociated symptoms: fever, no vomiting , no anorexiaSystemic inquiry, family, social, drug history- nonePast medical history- similar pain of shorter duration 2 months back
100Examination Appearance: In pain Temp. 38.6°C No jaundice Abdomen: Inspection- normal, few striae gravidarumPalpation- tenderness & guarding in RH, Murphy’s sign +ve ( tenderness & arrest of inspiration while palpating at costal margin)Percussion, auscultation- none
103Investigations Leucocytosis LFT: very slight elevation of bilirubin, normal alkaline phosphatase and transaminaseAbdominal ultrasonography: gall stones, gall bladder wall thickening, edema, pericholecystic fluid
104Pathophysiology Obstruction of the cystic duct Bacterial inflammation If obstruction persists- ischemia and gangrene of the gall bladderEventually perforation
105Management Nil by mouth IV fluid Parenteral antibiotics- (gram –ve and gram +ve organisms)- cephalosporinConsent for surgeryEarly laparoscopic cholecystectomy