Learning Objectives - Abdominal Pain

Question 1

List the 4 principle types of abdominal pain.

Answer 1

1. Parietal
2. Visceral
3. Vascular
4. Referred

Question 2

What is the pathophysiology of parietal abdominal pain?

Answer 2

Inflammation of the parietal peritoneum causes localized pain over the inflamed area.

The parietal peritoneum is innervated by somatic nerves (type A delta fibers) that terminate in the thalamus, allowing for localization of pain.

Question 3

How does parietal abdominal pain present?

Answer 3

• Pain worse with movement or changes in position (patient may lie still and resist movement)
• Rigid abdomen due to spasm of muscles over the affected peritoneum

Question 4

What is the pathophysiology of visceral abdominal pain?

Answer 4

Obstruction of a hollow viscera leads to deep, poorly localized pain. The viscera are innervated by type C sensory fibers that terminate in the brainstem.

Question 5

How does visceral abdominal pain present?

Answer 5

Pain may be colicky and come and go in waves (as in SBO) or it may be constant (acute biliary tree obstruction)

The patient may be restless as they attempt to find a comfortable position.

Question 6

What is the pathophysiology of vascular abdominal pain?

Answer 6

Viscera that are deprived of blood will inevitably cause pain. This can be sudden and intense in onset or gradual, depending on the vessel and structures involved.

Question 7

How does vascular abdominal pain present?

Answer 7

Inexorable worsening of symptoms and progression of the severity of the pain in a patient with VTE risk factors (hypercoagulability, smoking, HTN, pVD, AF).

If chronic, it may cause postprandial pain analogous to angina.

If acute, it may cause severe abdominal pain disproportionate to physical findings.

Question 8

What is the pathophysiology of referred abdominal pain?

Answer 8

Due to the innervation pattern of the viscera, pain from diseases of the heart, lungs, and testicles can be referred to the abdomen.

Question 9

How does referred abdominal pain present?

Answer 9

Poorly localized

Question 10

What are 4 causes of referred abdominal pain?

Answer 10

Pneumonia, empyema
MI
Testicular torsion

Question 11

What 3 major systems should be considered in the differential of abdominal pain?

Answer 11

GI
GU
CV

Question 12

DDx - GI causes of abdominal pain (16)?

Answer 12

1. Acute cholecystitis
2. Acute cholangitis
3. Small bowel obstruction
4. Spontaneous bacterial peritonitis
5. Appendicitis
6. Gastroenteritis
7. Gastritis
8. Pancreatitis
9. Hepatitis
10. PUD
11. Gastric outlet obstruction
12. Diverticulitis
13. Pseudomembranous colitis (C. difficile infection)
14. IBD (UC or Crohn’s)
15. IBS
16. Colon Cancer

Question 13

DDx - GU causes of abdominal pain (6)?

Answer 13

1. Pyelonephritis
2. Nephrolithiasis
3. PID
4. Ectopic pregnancy (if pre-menopausal)
5. Endometriosis (if pre-menopausal)
6. Ruptured ovarian cyst (if pre-menopausal)
7. Ovarian torsion

Question 14

DDx - CV causes of abdominal pain (4)?

Answer 14

1. Angina
2. ACS
3. Vasculitis
4. Mesenteric ischemia

Question 15

Pathophysiology of diverticulitis?

Answer 15

Inflammation caused by trapping of particulate matter and/or microperforation of a diverticulum

Question 16

Presentation of diverticulitis?

Answer 16

Fever, change in bowel habits (C or D)
Acute LLQ tenderness
Leukocytosis

Question 17

How is diverticulitis diagnosed?

Answer 17

CT Abdomen and Pelvis showing inflamed diverticula with thickening of the colon wall. May also identify complications, including abscess and perforation

Question 18

What is diverticulosis and how does it present?

Answer 18

Formation of diverticula when the mucosal layer of the intestine herniates through the muscularis propia, weakening the intestinal wall

Presents most commonly in older patients (>60) without symptoms or with chronic mild LLQ cramping relieved by defecation

Question 19

Diverticulosis is most common in the ___ colon in Western countries and in the ___ colon in Asian countries.

Answer 19

Sigmoid; ascending

Question 20

How does diverticular bleeding present?

Answer 20

Painless hematochezia, does not usually occur at the same time as diverticulitis

Question 21

Pathophysiology of pseudomembranous colitis?

Answer 21

Antibiotics kill healthy GI flora. This leads to overgrowth of C. difficile bacteria, which produce exotoxins, leading to mucosal injury, inflammation, and diarrhea

Question 22

Presentation of pseudomembranous colitis?

Answer 22

Watery diarrhea (cardinal symptom) with a low grade fever, abdominal cramping, and leukocytosis, often in patients with a recent history of antibiotic use or hospitalization. Note that community-acquired C. difficile is increasingly common.

Question 23

How is C. difficile diagnosed?

Answer 23

Toxin assay

Question 24

How is C. difficile managed?

Answer 24

IV fluids
Pain medication
Antibiotics (metronidazole or vancomycin)

Question 25

Etiology of acute mesenteric ischemia in the colon and small bowel?

Answer 25

Colitis - usually caused by an acute hypotensive event where blood flow to the colon is temporarily compromised Small bowel/mesentery - thrombosis or embolization of a mesenteric vessel, often in the setting of cardiac disease

Question 26

Which part of the colon is at highest risk for ischemic colitis?

Answer 26

Splenic flexure (pain in LUQ)

Question 27

Presentation of acute mesenteric ischemia?

Answer 27

``` Diffuse periumbilical abdominal pain Peritoneal signs (if advanced), absent/diminished bowel sounds, rigidity, may show signs of shock, pain out of proportion to the exam, distention, lactic acidosis ```

Question 28

How is acute mesenteric ischemia diagnosed?

Answer 28

CT with angiography

Question 29

How is acute mesenteric ischemia managed?

Answer 29

``` Admit to the ICU Notify surgery - depending on the cause, embolectomy, anticoagulation, stenting, or surgery may be appropriate Antibiotics IV fluids Oxygen Reversal of acidosis Vasopressor support ```

Question 30

Presentation of appendicitis?

Answer 30

Vague periumbilical pain that gradually increases in intensity and travels to the RLQ, vomiting fever Peritoneal findings if inflammation spreads to the parietal peritoneum More common in patients in their teens or twenties

Question 31

Presentation of gastroenteritis?

Answer 31

Fever, diarrhea, crampy abdominal pain, tenderness (usually generalized), increased suspicion if recent travel or suspicious food ingestion

Question 32

Presentation of IBD?

Answer 32

Fever, abdominal pain, diarrhea, chronic symptoms

Question 33

Compare the presenting complaints of CD and UC.

Answer 33

Both: diarrhea, fever, weight loss CD: abdominal pain, palpable mass UC: rectal bleeding

Question 34

Compare intestinal involvement of CD and UC.

Answer 34

Both: colon CD: ileum, rarely the jejunum/duodenum, esophagus

Question 35

Compare intestinal complications of CD and UC.

Answer 35

Both: cancer, perforation (rare) CD: perforation, abscesses, fistula UC: toxic megacolon

Question 36

Compare extra-intestinal complications of CD and UC.

Answer 36

Both: skin disease (erythema nodosum, pyoderma gangrenosum), arthritis (pauciarticular, large joints), hepato-biliary, renal calculi, anemia, thromboembolism risk, iritis/episcleritis (rare)

Question 37

Presentation of IBS?

Answer 37

Episodes of abdominal pain that can vary in nature and severity from patient to patient (functional, not associated with an anatomic cause, diagnosis of exclusion), chronic history of constipation, diarrhea, or both More common in younger females

Question 38

Most common causes of small bowel obstruction?

Answer 38

Adhesions from previous abdominal surgery (most common), hernias, tumors

Question 39

Presentation of small bowel obstruction?

Answer 39

Decreased or absent stool and flatus output (if there is a partial obstruction, liquid stool may be present), N/V, distended abdomen, diffuse tenderness, abdominal pain, +/-peritoneal signs, fever if perforation

Question 40

Presentation of ureteral stones?

Answer 40

Severe, colicky flank or lower quadrant pain radiating to the testicle (M) or vulva (F) Fever if complete obstruction with stasis or if struvite stones

Question 41

DDx - Upper Abdominal Pain, Vomiting, Fever, Alcohol Misuse (6)?

Answer 41

1. Cholecystitis 2. Gastritis 3. Pancreatitis 4. PUD 5. Small bowel obstruction 6. Spontaneous bacterial peritonitis

Question 42

Presentation of cholecystitis?

Answer 42

Vomiting, fever, RUQ colicky pain (may radiate under the right scapula) that steadily worsens until it is constant, may worsen with deep inspiration or jarring of the patient (if peritoneal inflammation) Would not expect shock/hypotension unless gangrene or gallbladder rupture has occurred

Question 43

Presentation of gastritis?

Answer 43

Abdominal pain, vomiting Would not expect peritoneal signs or fevers, would not expect tachycardia/hypotension unless significant Gi bleeding is present Alcohol use is a major risk factor

Question 44

Presentation of pancreatitis?

Answer 44

Vomiting, fever, peritonitis/peritoneal signs, SIRS (if release of lypolytic enzymes)

Question 45

Two most common causes of pancreatitis?

Answer 45

Heavy alcohol use (#1) | Biliary stone obstructing the pancreatic duct (#2)

Question 46

Presentation of PUD?

Answer 46

Vomiting, coffee-ground emesis if bleeding is present Would not expect fever/systemic symptoms unless bleeding/perforation present Heavy alcohol use is a risk factor

Question 47

Presentation of spontaneous bacterial peritonitis?

Answer 47

Poorly localized pain (inflammation/infection of peritoneal fluid due to gut translocation of bacteria), possible vomiting, ascites, ileus, possible guarding/rebound tenderness

Question 48

List the possible components of a work-up for abdominal pain (14).

Answer 48

1. CBC - Leukocytosis (infection/inflammation) - Anemia, macrocytosis (alcohol abuse) - Thrombotyopenia (cirrhosis or sepsis) 2. BMP - Volume status - Kidney function (kidney failure in advanced liver disease, AKI with severe infection/inflammation/hypovolemia) 3. LFTs - Hepatobiliary disease 4. Lipase - Essential to diagnose pancreatitis - More specific/sensitive than amylase (can be elevated in acute gastroenteritis/liver failure); may be elevated in renal failure 5. Hemoccult - Very sensitive, less useful if acutely ill 6. Cardiac enzymes 7. UA - Volume status, UTI 8. Pregnancy test 9. Serum/urine toxicology screen 10. Abdominal series (flat/upright abdominal radiographs, upright chest radiograph) - Perforation or obstruction 11. CT Abdomen/Pelvis - Diverticulitis, ischemic colitis, appendicitis, other intra-abdominal problems 12. C. difficile toxin assay 13. Stool cultures - Bacterial causes of gastroenteritis - Viral cultures not routinely done in immunocompetent hosts 14. Colonoscopy

Question 49

Radiographic findings of perforation/obstruction?

Answer 49

Air under the diaphragm is pathognomonic of a perforated viscus Air-fluid levels throughout the bowel can be seen in obstruction

Question 50

When is a colonoscopy contraindicated in evaluating abdominal pain?

Answer 50

If concern for diverticulitis, as increased pressure could cause a perforation

Question 51

DDx - abdominal pain with a history of alcohol abuse?

Answer 51

Pancreatitis Gastritis Hepatitis/cirrhosis

Question 52

DDx - crampy abdominal pain?

Answer 52

Diverticulitis, gastroenteritis, intermittent obstruction of a viscus (biliary colic, renal colic, bowel obstruction)

Question 53

What are the major causes of an acute abdomen?

Answer 53

Peritonitis from perforation or inflammation of an organ Obstruction

Question 54

What is the most specific exam finding for diagnosing peritonitis?

Answer 54

Rigidity (involuntary contraction of the abdominal muscles)

Question 55

What is the difference between rigidity and guarding?

Answer 55

Rigidity - involuntary Guarding - voluntary contraction of abdominal wall, muscles will relax if the patient is relaxed or distracted (less specific, more sensitive)

Question 56

What is Murphy's sign?

Answer 56

Abrupt cessation of inhalation when palpating deeply under the liver edge, indicates cholecystitis

Question 57

Which peritoneal sign is non-specific and does very little to narrow a differential?

Answer 57

Rebound tenderness

Question 58

When should surgeons be consulted in the setting of abdominal pain?

Answer 58

Cholecystitis, small bowel obstruction, perforation of an abdominal organ

Question 59

What is the cornerstone of management for uncomplicated diverticulitis?

Answer 59

Antibiotics for 7-10 days

Question 60

What bacteria must be covered in treating diverticulitis?

Answer 60

Bowel flora: GN rods (E. coli), enteric GP streptococci, anaerobes (B. fragilis)

Question 61

What is the initial antibiotic therapy of choice for diverticulitis?

Answer 61

Metronidazole + FQ (like ciprofloxacin)

Question 62

List 2 other reasonable combinations for antibiotic treatment of diverticulitis.

Answer 62

1. Metronidazole + 3rd generation cephalosporin (like ceftriaxone) 2. Single agent therapy with ertapenem, moxifloxacin, or cefoxitin

Question 63

What are 3 oral treatment options for diverticulitis?

Answer 63

1. Metronidazole + FQ 2. Metronidazole + TMP-SMX 3. Moxifloxacin

Question 64

2010 IDSA guidelines recommend what antibiotics for diverticulitis because of high rates of resistance among community-acquired E. coli?

Answer 64

Ampicillin-Sulbactam (Unasyn) Amoxicillin-Clavulanate (Augmentin)

Question 65

In addition to antibiotics, discuss additional management of diverticulitis.

Answer 65

1. Supportive care (NPO or bowel rest, IV fluids) 2. IV narcotics for severe pain 3. Follow-up colonoscopy in 2-6 weeks to explore the extent of diverticulosis and rule out polyps/cancer 4. High-fiber diet (decrease constipation/intraluminal pressure, decrease chance of recurrence)

Question 66

When may surgery be indicated for diverticulitis?

Answer 66

Recurrent diverticulitis | Management of complications (free air from perforation, complicated abscess or phelgmon, obstruction, fistula)

Question 67

Prognosis of diverticulitis?

Answer 67

~1/3 will have recurrent abdominal cramps 1/3 will have another frank episode Some with recurrent episodes may require surgery to resect the diseased portion of bowel

Question 68

Recommend a basic management plan for uncomplicated pancreatitis (no vomiting, no ileus)

Answer 68

Medical management with IV fluids, pain control, and a soft, low fat diet as tolerated

Question 69

When should surgery be consulted in a patient with pancreatitis?

Answer 69

Impacted gallstone not extracted with ERCP, pancreatic abscess, necrotic pancreatitis, symptomatic pancreatic pseudocyst

Question 70

When is imaging indicated for pancreatitis?

Answer 70

Confirm the diagnosis when presentation or labs are confusing Detect gallstones as a possible cause Detect pancreatitic necrosis, abscesses, and other complications Guide percutaneous drainage if needed

Question 71

Management of chronic pancreatitis?

Answer 71

1. Narcotic analgesics for pain 2. Pancreatic enzymes 3. H2 blockers (prevent degradation of pancreatic enzymes by gastric acid) 4. Insulin (if severe endocrine insufficiency) 5. Alcohol abstinence 6. Frequent small volume low fat meals

Question 72

What is the role of antibiotics in pancreatitis?

Answer 72

Remains controversial For mild cases, prophylaxis is clearly not indicated. With increasing severity of illness, organ dysfunction, and worsening pancreatic necrosis, some studies have shown benefit with prophylaxis and some have not. Empiric therapy should be used in those who appear to have infection complicating a severe pancreatitis course, such as infected pseudocyst or pancreatic abscess complicating extensive necrosis