GI - Lower and diffuse abdominal pain, Peritonitis, Abdominal emergencies Flashcards
3 physiological origins of abdominal pain
Visceral pain
Parietal
Referred pain
Visceral abdominal pain
Origin and innervation
Cause
Site
Character
Origin and innervation: Visceral peritoneum innervated bilaterally by autonomic nerves
Cause: Stretching, inflammation, ischaemia
Site: Midline in upper (foregut), central (midgut) or lower abdomen (hindgut)
Character: Dull, poorly localized
Parietal abdominal pain
Origin and innervation
Cause
Site
Character
Origin and innervation: Parietal peritoneum innervated unilaterally by somatic nerves
Cause: Irritation (inflammatory or mechanical)
Site: Well-localized over irritated area
Character: Sharp, severe
Referred abdominal pain
Origin and innervation
Cause
Site
Character
Origin and innervation: Innervation shared by both somatic nerves and visceral organs
Cause: same as visceral pain - Stretching, inflammation, ischaemia
Site: Well-localized in a distant area
Character: Sharp
Causes of RLQ pain
Ileum: ileitis (Crohn’s disease, Yersinia), Meckel’s diverticulitis
Caecum/Rt colon: acute appendicitis, diverticulitis, caecal ischaemia, colitis (infective, IBD, radiation), CA colon/caecum
O/G: torsion/ruptured of ovarian cysts, ectopic pregnancy
Urological: ureteric colic, testicular torsion
Others: strangulated inguinal/femoral hernia, mesenteric adenitis
Causes of LLQ pain
Sigmoid colon/Lt colon: colitis (infective, IBD, radiation), diverticulitis, CA Lt colon/sigmoid
O/G: torsion/rupture of ovarian cyst, ectopic pregnancy, PID
Urological: ureteric colic, testicular torsion
Others: strangulated inguinal/femoral hernia
Ddx peri-umbilical pain
Small bowels: small bowel obstruction, gastroenteritis, early appendicitis, mesenteric ischaemia, IBD
Retroperitoneal: ruptured AAA, pancreatitis
Ddx hypogastric/ suprapubic area pain
Large bowels: large bowel obstruction, colorectal CA
Urological: AROU, bladder stones, cystitis/UTI
O/G: PID, degenerating fibroid, adenomyosis/endometriosis, ectopic pregnancy
Ddx diffuse/ non-specific abdominal pain
Bowels: gastroenteritis, constipation, uncomplicated bowel obstruction
Peritoneum: generalized peritonitis, intra-abdominal haemorrhage, ruptured viscus\
Medical causes: DKA, hypercalcemia, herpes zoster, anaphylaxis, porphyria
Ddx Right flank pain
Kidney: pyelonephritis, renal infarct, obstructive uropathy (hydronephrosis), renal stone, RCC
(Biliary)
Ddx Left flank pain
Kidney: pyelonephritis, renal infarct, obstructive uropathy (hydronephrosis), renal stone, RCC
(Splenic
Ddx RUQ pain
Liver: hepatitis, hepatomegaly, liver abscess
Biliary: cholangitis, cholecystitis, cholelithiasis, choledocholithiasis
Thoracic: pneumonia, pleural effusion
Others: subphrenic abscess
Ddx epigastric pain
Oesophagus: oesophagitis, GERD, Boerhaave’s syndrome
Stomach: gastritis, peptic ulcer, gastric volvulus, gastric outlet obstruction, CA stomach
Pancreas: pancreatitis, CA pancreas
Thoracic: MI, pericarditis
(Hepatobiliary)
Others: rAAA,
Ddx LUQ pain
Spleen: rupture, infarct, splenomegaly
Pancreas: pancreatitis
Thoracic: pneumonia, pleural effusion, MI
Most common causes of acute, severe abdominal pain
- *1.Inflamed viscus**
- Appendicitis
- Ileitis
- Colitis
- Diverticulitis
- *2. Perforated viscus**
- Peptic ulcer
- Ischaemic bowel
- *3. Obstructed viscus**
- IO, strangulation
- (Ureteric colic)
- (Biliary colic)
- *4. Infarcted viscus**
- Mesenteric ischemia
- Ischemic colitis
- *5. Intra-abd or retroperitoneal haemorrhage**
- Ruptured AAA
- Ruptured spleen
- Ectopic pregnancy
- *6. Extra-GI causes**
- Pleurisy
- MI
- DKA…
Ddx the following S/S with abdominal pain
Signs of local inflammation (early) or generalized peritonitis (late):
- Pain, tenderness, guarding, rebound tenderness
- ↓bowel sounds
- Tachycardia, fever
Inflamed viscus
- Appendicitis
- Ileitis
- Colitis
- Diverticulitis
Ddx the following S/S with abdominal pain
Colicky pain, vomiting, distension, absolute constipation
Local/generalized peritonitis
Obstructed viscus
- IO: Luminal obstruction or strangulation
Ddx the following S/S with abdominal pain
Local/generalized peritonitis Signs of hypovolemic shock (late)
Infarcted viscus
- Mesenteric ischemia
- Ischemic colitis
Ddx the following S/S with abdominal pain
Signs of generalized peritonitis
Cullen’s sign, Grey Turner’s sign, shifting dullness, shoulder pain
Signs of hypovolemic shock (early)
Intra-abd or retroperitoneal haemorrhage
- Ruptured AAA
- Ruptured spleen
- Ectopic pregnancy
Ddx acute abdomen by onset/ duration of second, minutes or over hours
Within seconds:
→ Infarction, eg. MI, mesenteric occlusion
→ Haemorrhage, eg. ruptured AAA
→ Perforation, eg. PPU
Within minutes:
→ Inflammatory, eg. acute appendicitis, pancreatitis, diverticulitis
→ Colic, eg. biliary colic, ureteric colic, IO
→ Ischaemia, eg. mesenteric ischaemia, strangulated IO, volvulus
Over hours:
→ Inflammatory, eg. appendicitis, cholecystitis
→ Obstruction, eg, non-strangulated IO, urinary retention
→ Mechanical, eg. ectopic pregnancy, perforating tumours
Differentiate causes and character of constant vs colicky vs stretching abdominal pain
Constant pain due to inflammation, infiltration, ischaemia or infarction
→ Severe, persistent, made worse by local or general movement
Colicky pain due to hyperperistalsis against obstruction
→ Waxing and waning gripping pain
→ Intestinal obstruction/ureteric colic: with periods of complete cessation (true colic)
→ Biliary colic: severe, constant with painful exacerbations but no complete pain-free periods
Stretching pain due to prolonged obstruction to outflow of hollow viscus
→ Constant stretching pain but not colicky
Ddx the following abdominal pain radiation patterns
- Back
- Right Shoulder tip
- Right Scapular spine
- Loin to groin
- Testicles to flank
- Flank
Radiation:
□ Back: pancreatitis, AAA, aortic dissection, posterior stomach/duodenal ulcer
□ R Shoulder tip: haemoperitoneum (eg. ruptured ectopic, splenic ruptured)
□ R Scapular spine: gallbladder
□ Loin to groin: renal colic
□ Testicles to flank: testicular pain
□ Flanks: pyelonephritis, retroperitoneal haematoma, AAA
Outline history taking approach to acute abdomen
- Onset/ duration/ progression
- Quality: constant/ colicky/ stretching
- Site and radiation
- Severity
- Exacerbating and relieving factors
- Associated symptoms: Screen UGI, LGU, Urology, vascular and O/G pathologies
- PMH: Risk factors for IO, Perforation, AAA, LMP…etc
- Drug history
- Social and family history
- Menstrual and sexual history
First-line investigations and rationale for acute abdomen
Bedside
Bloods
Imaging
Bedside: Urinalysis (UTI, stones), pregnancy test (ectopic preg.)
Blood count: RBC for chronic bleed, WBC for infection
LFT: hepatic vs obstructive jaundice
RFT: Hydration status, HypoK + HypoCl for chronic vomiting, HypoK + HypoCa for ileus, Cr for scans
Amylase: acute pancreatitis
ABG: Metabolic acidosis + lactate for ischemia, Metabolic alkalosis for vomit
Clotting profile, T/S for transfusion prep and surgery
Imaging:
Erect CXR (free gas under diaphragm for perforation)
Erect and supine AXR (IO, air-fluid levels, coffee bean sign, stones, sentinel loop sign, pancreatic calcification)
USG: Gallstones, cholecystitis
CT Contrast: mesenteric ischemia, retroperitoneal leaks or stones
Endoscopy
Acute appendicitis
Pathology
Demographic
Pain character
Associated S/S
Pathology: Unknown, likely obstruction by faecolith, lymphoid hyperplasia, stricture, carcinoid tumour
Demographic: young adults and teenagers
Pain:
- Begins as vague ‘colicky’ paraumbilical pain
- Shifts to Rt iliac fossa and becomes more severe, constant and localized after a few hours-days
S/S:
- Anorexia (~75%) before onset of pain
- Nausea, vomiting after onset of pain
- Fever often after 6h
- Generalized peritonitis if progressed
- Retrocaecal (64%) → RLQ, flank pain
Pelvic (32%) → bladder (dysuria, frequency), large bowel (diarrhoea) S/S
Acute appendicitis
Signs: general, abdomen
General:
- Unwell, low-grade pyrexia
- Tachycardia
- Fetor oris (halitosis)
- Limited lower abd resp movt
Abdomen:
- RLQ tenderness and guarding (max over McBurnley’s point)
- Tenderness at Flank (retrocaecal), RUQ (subhepatic)
- ± RLQ tender mass (Indistinct, dull on percussion)
Acute appendicitis
4 special signs elicited for confirmation
Main mode of diagnosis
Specific signs:
- Rovsing’s sign = pressure on Lt iliac fossa cause pain in Rt iliac fossa
- Cough sign = Rt iliac fossa pain on coughing due to localized peritonitis
- Obturator sign = RIF pain on internal rotation of flexed Rt hip due to spasm of obturator internus
- Psoas sign = RIF pain on Rt hip flexion due to inflamed retrocaecal appendix is lying on psoas muscles
Mostly clinical Dx, USG or CT may be helpful
Mesenteric adenitis
- Pathology, causative agents
- Demographic
- Pain
- Associated S/S
Inflammation of mesenteric LNs (common mimic of acute appendicitis)
Causative agents:
- B-hemolytic streptococcus, E. coli, Streptococcus viridans, Yersinia,
- Coxsackievirus, Rubeola, Adenovirus
Demographic: usu. children
Pain: central abd pain but can cause RLQ pain
Associated S/S:
- Preceding URTI (high fever, sore throat) and cervical LN enlargement
- Pain may move at lateral decubitus position when glands move over with mesentery
Acute diverticulitis
Pathology
Demographic
Pain character
Associated S/S
Pathology: Inflammation and microperforation of colonic diverticula at mucosal herniations, mostly at sigmoid colon
Demographic: 50-70y, Westerners
Pain:
- Gradual onset of mild intermittent lower abd pain
- Shift to L/R iliac fossa and becomes more severe and constant
Associated S/S:
- Fever, tenderness and guarding
- Nausea, poor appetite, constipation (vomiting and diarrhea are RARE)
- Dysuria, ↑frequency
Acute diverticulitis
Specific Signs
Preceding S/S
Complications
Specific signs:
- Lie still, pyrexia, tachycardia
- Iliac Fossa tenderness and guarding
- ±IF mass tender sausage-shaped dull on percussion
- Reversed Rovsing’s sign: pressure on Rt side of abdomen may induce pain on left
- PR may show pain
Preceding S/S:
- Hx of diverticular disease, flatulence, distension, L/RIF pain
Complications
- localized abscess, purulent peritonitis or fecal peritonitis
Acute diverticulitis
Main mode of Dx
Treatment
CT confirms diagnosis and assesses severity
Tx:
- Antibiotics
- Image-guided drainage
- Laparoscopy and lavage (purulent peritonitis)
- Laparotomy and bowel resection (Fecal peritonitis)
Ileitis
Causes
Main mode of Dx
Presentation
Causes:
- Crohn’s disease
- TB
- Radiation enteritis
- Bacterial infection: Campylobacter, Yersinia, Salmonella
Main mode of Dx:
- Incidental finding of inflamed terminal ileum during operations
Presentation:
Crohn’s ileitis (commonest)
- Episodic colicky abdominal pain
- Watery, fatty or inflammatory (less common) diarrhoea
- Malabsorptive features
- ± subacute/acute IO (fibrotic strictures)
- ± RLQ mass
Merkel’s diverticulum
Pathology
Demographic
Pain
associated S/S
Pathology:
- Remnant of vitelline duct adhered to umbilicus, 2 inches long, 2 feet from ileocaecal junction
- ectopic gastric or pancreatic mucosa cause inflammation at site, cause bleeding, perforation, volvulus or intussusception
Demographic: 2% population, usually present at 2 years old
Pain:
- Central abdominal pain - ectopic mucosa cause ulceration or bleeding
- Colicky abdominal pain - act as head of intussusception causing IO or volvulus
Associated S/S:
- Highly similar to acute appendicitis
Merkel’s diverticulum
Main mode of diagnosis
Treatment
Main mode of diagnosis: CT scan/ incidental finding during appendicectomy
Treatment:
Antibiotic coverage + diverticulectomy/ small bowel resection
Testicular torsion
Demographic
Pain character
Associated S/S
Specific sign on exam
Treatment
Demographic: 10-15
Pain character: Severe pain in testes and groin +/- radiation to loin
Associated S/S: preceding vague abdominal pain
Specific sign on exam: Tender and high-lying testicles
Treatment: Surgical emergency
Surgical exploration +/- Orchidopexy, Orchidectomy
Ectopic pregnancy and abdominal pain
Pathology
Demographics
Pain character
Associated S/S
Complications
Pathology: Tubal pregnancy ± rupture into abdominal cavity at 6 weeks
Demographics: Female in child-bearing age, previous PID, ectopic preg.
Pain character: Sudden onset severe lower abdominal pain on side of ectopic pregnancy
Associated S/S : Preceded by a few days of mild abd pain
Complications:
- Generalized Peritonitis
- Hypovolemic shock (fainting, collapse) if ruptured
- Shoulder tip pain if blood collects beneath the diaphragm
Ectopic pregnancy and abdominal pain
Main mode of diagnosis
Treatment
Dx: Ultrasound
Tx:
Large bore IV cannula and resuscitation
Urgent laparoscopy and salpingotomy/ salpingectomy
Pelvic inflammatory disease
Pathology
Demographics/ risk factors
Pain character
Associated S/S
Pathology: Salpingitis and associated infection of adnexa supporting tissue from ascending vaginal infection (e.g. chlamydia, gonorrhoea…)
Demographics/ risk factors: Sexually active female under 40y, history of IUCD, STD, gynaecological procedures
Pain character: Gradual onset of constant lower abd pain ± radiation into back
Associated S/S:
- Preceded by a few months of menstrual irregularities and dysmenorrhoea
- purulent yellow-white vaginal discharge by a few days
- dysuria and urinary frequency
- dyspareunia
Pelvic inflammatory disease
Signs (general, abdominal, genital)
Treatment
General Signs:
High fever (38-39.5oC) Lower abd tenderness, guarding
Vaginal exam:
- Yellow-white introital discharge
- Adnexal tenderness on bimanual palpation
- Chandelier sign - painful cervical excitation**
- Pus discharge from cervical canal in speculum examination
Treatment:
- Antibiotics
- Drainage of tubovarian abscess
Torsion/ ruptured ovarian cyst
Pathology
Pain character
Associated symptoms
Main mode of diagnosis
Treatment
Pathology: Ovarian cyst complication
Pain character: Sudden severe unilateral lower abd pain during agitating movement (eg. exercise)
Associated symptoms:
- S/S of intra-abdominal bleeding
- ± S/S of hypovolemic shock
- ± lower abd tenderness and guarding
Main mode of diagnosis: USG or CT
Treatment: Laparoscopy ovarian cystectomy/ oophorectomy
Ureteric colic
Pathology
Pain character
Associated S/S
Signs
Pathology: Obstruction in ureter due to ureteric stones
Pain character:
- Severe, gripping true colic radiating down from renal angle, parallel to inguinal ligament into groin
- Alleviate by rolling around bed or walking around
Associated S/S:
- Autonomic symptoms (sweating, N/V)
Gross or microscopic haematuria
Signs
- May have renal angle tenderness
Urinalysis shows gross or microscopic haematuria
Large bowel obstruction
Common Causes
S/S
Common causes:
- Colon cancer
- Volvulus
- Diverticular stricture
- Pseudo-obstruction
S/S:
- Cramping pain
- Vomiting
- Abdominal distension
- Constipation
Outline list of physical exams for suspects large bowel IO
General:
- Hydration status (3rd space loss)
- Tachycardia and hypotension (Hypovolemia)
Abdominal:
- Peritoneal signs/ localized tenderness
- Hernial orifices (hernia incarceration)
- Bowel sounds and percussion: Resonance over distended bowel, High-pitched tinkling BS, absent BS
- Rectal examination (impaction, mass)
Outline first-line investigations for large bowel IO
Full bloods
Imaging:
- Plain abdominal X-ray
- Abdominal CT with contrast
- Contrast study: e.g. Gastrografin follow-through enema
Distinguishing features of large and small bowel on X-ray
Xray:
Small bowel = central with valvulae conniventes
Large bowel = Peripheral with haustations
Treatment of large bowel IO
(basic, surgical)
Diet:
- Nil Per Oral
- IV fluid resuscitation: secure IV access
- NG tube decompression if IO
Definitive surgical treatment:
- Colonic stenting
- Endoscopic decompression
- Bowel resection
- Stoma
Ischemic bowel
Causes of ischemia
Thromboembolism
Venous occlusion
Non-obstructive mesenteric ischaemia
Chronic mesenteric ischemia (e.g. chronic anaemia, vasopressor use…etc)
Mechanical (volvulus, hernia)
Ischemic bowel
Demographics
Pain character
Associated S/S
Signs on PE
Complications
Demographics: Elderly, with history of AF or IHD
Pain character: Constant, severe, non-specific abdominal pain
Associated S/S: Rectal bleeding or bloody diarrhea, colic
Signs on PE:
- Lie still, pale, sweating, tachycardia
- Rarely peritoneal signs
Complications:
- Metabolic acidosis, renal failure, ileus, shock, death
Peritonitis
Classification by location, underlying causes
Classification by primary, secondary and tertiary
Location:
Localized vs generalized/ diffuse
Underlying causes:
e.g. Spontaneous bacterial peritonitis, Chemical peritonitis
□ Primary peritonitis: not a/w 1o pathology → bacteria often from haematogenous dissemination
□ Secondary peritonitis: secondary to pathological process in abdominal viscera, commonly perforated viscus
□ Tertiary peritonitis: persistent peritonitis after treatment, immunocompromised state or opportunistic infection of peritoneum
Peritonitis
Pathogenesis of hypovolemia and systemic shock
inflamed peritoneum becomes oedematous, hyperaemic and covered w/ fibrinous exudates → resulting in
□ Sequestration of large amount of protein-rich fluid
□ Septicaemia and endotoxaemia
□ Hypovolaemia and shock
Peritonitis
S/S - General and abdominal
General:
- Fever, tachycardia (often early), tachypnoea
- Septic shock
- Features of visceral inflammation
- Malaise, anorexia, nausea
Abdominal:
Peritoneal irritation:
- Burning pain: initially localized and later spread, often ↑ w/ movement and coughing
- Peritoneal signs: tenderness, rebound tenderness, guarding, rigidity
Paralytic ileus:
- Abdominal distension
- Absent bowel sounds (paralytic ileus)
List causes of primary bacterial peritonitis
Typical pathogens
Risk factors
- Spontaneous bacterial peritonitis
- Tuberculous peritonitis
- Peritonitis associated with Chronic Ambulatory Peritoneal Dialysis
Typical pathogens: normally monomicrobial (secondary = polymicrobial)
- Strep. pneumoniae
- Group A streptococcus
- Enteric organisms
Risk factors:
- Ascites
- Malnutrition
- Intra-abdominal malignancies
- Immunosuppression
- Splenectomy, Chronic liver disease. CKD
Outline all metrics of peritoneal fluid analysis
Appearance: serous, blood-stained, purulent, bile-stained, feculent → ‘E’ OT if bile-stained (HBP/SB perf) or feculent (LB perf)
Cell count: neutrophil >500/μL in peritonitis
Biochemistry:
- ↓Glc, ↑protein, ↑LDH cf serum → indicates bacterial inf’n
- ↑amylase → indicates perforated GI tract from pancreatitis
- ↑Cr compared to serum → indicates perforated urological tract/ urine leak
Microbiology: Gram stain, culture (aerobic, anaerobic, AFB, fungal)
Tuberculous peritonitis
S/S
Mode of investigation and diagnosis
S/S:
- Non-specific: low-grade fever, weight loss
- Insidious onset of abdominal pain
- Rare/ minimal peritoneal signs
Dx:
- Laparoscopy and biopsy of peritoneum
- AFB smear not reliable (false negatives)
Acute secondary bacteria peritonitis (most prevalent peritonitis**)
Causes
Severe inflammation of abdominal organ - e.g. diverticulitis, cholecystitis, appendicitis
Perforation of GIT - spontaneous, trauma, iatrogenic
Anastomotic leak - chemical peritonitis by gastric juice/ bile/ pancreatic secretions/ urine/ blood
Ischemia of abdominal organs
Acute secondary bacterial peritonitis
Causative agents
POLYMICROBIAL (cf monomicrobial in primary bacterial peritonitis)
Gram negative, enterobacteria: (most common)
- E.coli. Enterobacter, Proteus, Psudomonas
Gram positive:
- Streptococcus, Enterococcus
Anaerobes
- Bacteroides
Complications of peritonitis
Septicemia, endotoxemia
Hypovolemia and shock
Sequestration of protein rich fluid in peritoneum
Treatment of acute secondary bacterial peritonitis
Supportive: IV fluid resuscitation, NG tube, Foley catheter, O2, pain relief
Broad-spectrum Abx: usually 2G ceph (eg. cefuroxime (Zinacef)) + metronidazole (Flagyl)
Definitive treatment:
Drainage for stable, localized pathologies, eg. percutaneous drainage of abscess, ERCP for biliary
Surgical emergency: Laparoscopy for PPU repair, cholecystectomy, bowel resection, appendicectomy/ exploratory laparotomy
Why does peritonitis present late in elderly
Poor detailed history
Confused or demented
Peritoneal signs may be mild
