1. Approach to abdominal pain
Pongkamon Tongpong

2. Outlines Introduction Types Approach to acute care
History taking and physical examination
Investigations
Differential diagnosis
Special settings
Cases

3. Introduction Abdominal pain can be a challenging complaint
Benign complaint but it can also herald serious acute pathology
Clinicians have to determine which patients can be safely observed or treated symptomatically and which required further investigation or specialist referral
Accuracy of history and physical examination for the serious causes of abdominal pain, alone or combined with focused investigations, have yield good results

4. Outlines Introduction Types Approach to acute care
History taking and physical examination
Investigations
Differential diagnosis
Special settings
Cases

5. Types Acute VS Chronic Visceral VS parietal VS referred pain
Chronic : duration more than 7 days
Visceral VS parietal VS referred pain
Surgical VS non-surgical conditions : required surgical management

6. Types of pain
Parietal pain
Visceral pain
Referred pain

7. Nerve transmission
Two distinct types of afferent nerve fibers (autonomic and somatic nervous system)
Unmyelinated C fibers - visceral
Myelinated A-δ fibers - somatic-parietal
Interplay between the two systems results in a third type of pain, referred pain

8. VISCERAL PAIN
Transmitted by C fibers - muscle, periosteum, mesentery, peritoneum, and viscera
Dull, cramping, burning, poorly localized
More gradual in onset and longer in duration than somatic pain
Usually perceived in the midline, in the epigastrium, periumbilical region, or hypogastrium

9. Distribution of autonomic nervous system

10. Abdominal visceral nociceptors
Respond to mechanical and chemical stimuli
Mechanical signal are stretch
Cutting, tearing, or crushing of viscera does not result in pain
Stretch receptors are located in muscular layers of hollow viscera
Between muscularis mucosa and submucosa
Serosa of solid organs, and in the mesentery (adjacent to large vessels)

11. Mechanoreceptor stimulation
Distention of hollow viscus (e.g., intestinal obstruction)
Forceful muscular contractions (e.g., biliary pain or renal colic)
Rapid stretching of solid organ serosa or capsule (e.g., hepatic congestion)
Torsion of mesentery (e.g., cecal volvulus)
Tension from traction on mesenteric vessels (e.g., retroperitoneal or pancreatic tumor)

12. Chemical nociceptors
Contained mainly in mucosa and submucosa of hollow viscera
Activated directly by substances released
Response to local mechanical injury, inflammation, tissue ischemia and necrosis, and noxious thermal or radiation injury

13. SOMATIC-PARIETAL PAIN
Mediated by A-δ fibers
Distributed principally to skin and muscle
Sudden, well-localized pain, such as that which follows an acute injury
Convey pain sensations through spinal nerves
Activates local regulatory reflexes and long spinal reflexes
Transmitting pain sensation to central nervous system

14. Somatic-parietal pain
Aggravated by movement or vibration
Reach spinal cord in peripheral nerves
Sixth thoracic (T6) to first lumbar (L1) vertebra

15. REFERRED PAIN
Result from adjacent structures that subsequently migrate away from each other
For example, central tendon of the diaphragm begins its development in the neck
Shows diaphragmatic irritation from a subphrenic hematoma or splenic rupture may be perceived as shoulder pain (Kehr's sign)

16. Outlines Introduction Types Approach to acute care
History taking and physical examination
Investigations
Differential diagnosis
Special settings
Cases

17. APPROACH TO ACUTE CARE A: Airway B: Breathing C: Circulation
If hemodynamic instability is apparent
Surgical consultation should be sought immediately
Consideration to endotracheal intubation and resuscitation

18. GI organs
KUB organs
Genital organs

19. Outlines Introduction Types Approach to acute care
History taking and physical examination
Investigations
Differential diagnosis
Special settings
Cases

20. History taking Onset of pain , frequency, duration
Character : visceral pain usually dull, poorly localized. Parietal pain usually sharp and very well localized.
Location of pain
Radiation of pain
Severity of pain
Aggravating or relieving factors ex. Food , exertion, defecation, antacid
Associated symptoms : fever, N/V, diarrhea, constipation, GI bleeding, jaundice, change in stool and urine color, abnormal vaginal bleeding

22. History taking Past medical and surgical history
Family history of bowel disorder
Alcohol intake
Medication (included over-the-counter drugs)
Menstruation and contraception in women

23. Physical examination Vital signs
General appearance : posture, degree of discomfort, facial expression, breathing pattern
Abdominal examination
Systemic examination eg. cardiac arrhythmia

25. Abdominal Examination
Inspection - entire abdomen, from the nipple line to the thighs
Assessment of bowel sounds and their character
At least two minutes and in more than one quadrant
Distinguish high-pitched of a mechanical small intestinal obstruction from the more hollow sounds of toxic megacolon

26. Abdominal Examination
Tenderness is detected, an assessment for rebound tenderness to look for evidence of peritonitis
Palpation, ask for pain location and that area should be palpated last to detect involuntary guarding and muscle rigidity
Patient with rigid abdomen rarely revealed any additional findings (eg. mass)
Genital, Rectal, and Pelvic Examinations

27. Outlines Introduction Types Approach to acute care
History taking and physical examination
Investigations
Differential diagnosis
Special settings
Cases

28. LABORATORY DATA Complete blood count, and urinalysis
Determination of serum electrolyte, blood urea nitrogen, creatinine, and glucose
Urine pregnancy testing in all women of reproductive age with abdominal pain
Liver biochemical tests and serum amylase levels for patients with upper abdominal pain or with jaundice

29. LABORATORY DATA
Metabolic acidosis, an elevated serum lactate level, or a depressed bicarbonate level
Associated with tissue hypoperfusion and shock
Likely to require urgent surgical intervention or intensive care

30. Imaging High-speed helical CT
Sensitivity and specificity of CT scanning for acute appendicitis are 94% and 95%,
Negative CT scan in the setting of acute abdominal pain has considerable value in excluding common disorders

31. Ultrasonography
Rapid, bedside test to detect fluid in the abdominal cavity

32. OTHER DIAGNOSTIC TESTS
MRI and radionuclide scanning and endoscopy
A secondary role in the evaluation
Guided by results of CT or ultrasound

33. Outlines Introduction Types Approach to acute care
History taking and physical examination
Investigations
Differential diagnosis
Special settings
Cases

34. Causes of acute abdominal pain
Etiology
Patients (%)
Non-specific abdominal pain 35
Appendicitis 17
Bowel obstruction 15
Urologic disease 6
Biliary disease 5
Diverticular disease 4
Pancreatitis 2
Medical illnesses 1
Other

35. Parietal pain

36. Parietal pain

37. Visceral pain
1. Epigastrium
2. Mid-abdomen
3. Hypogastrium

40. Outlines Introduction Types Approach to acute care
History taking and physical examination
Investigations
Differential diagnosis
Special settings
Cases

41. Extremes of Age
Cause in infancy - intussusception, pyelonephritis, gastroesophageal reflux, Meckel's diverticulitis, and bacterial or viral enteritis
In children - Meckel's diverticulitis, cystitis, pneumonitis, enteritis, mesenteric lymphadenitis, and inflammatory bowel disease are prevalent

42. Extremes of Age In adolescents – PID, IBS and other common causes
In children of all ages, two of the most common causes of pain are acute appendicitis and abdominal trauma secondary to child abuse

43. Pregnancy
Develop acute appendicitis and cholecystitis at the same rate as their nonpregnant
Placental abruption and pain related to tension on the broad ligament, must be consider
Radiation injury to the developing fetus must be considered

44. Immunocompromised Hosts
Neutropenic enterocolitis
Drug-induced pancreatitis
Graft-versus-host disease
Pneumatosis intestinalis
Cytomegalovirus (CMV) and fungal infection

45. HIV associated Primary peritonitis
Spontaneous intestinal perforation, usually secondary to CMV infection
Tuberculous peritonitis is a consideration

46. ACUTE APPENDICITIS
Overall incidence of appendicitis is approximately 11/10,000 population
Typically, begins with prodromal symptoms of anorexia, nausea, and vague periumbilical pain
Pain migrates to RLQ and peritoneal signs develop
In uncomplicated appendicitis, a low-grade fever to 38 C and mild leukocytosis
A higher temperature and WBC are associated with perforation and abscess formation

47. ACUTE BILIARY DISEASE Range from biliary pain to acute cholecystitis
Biliary pain is a syndrome of RUQ or epigastric pain, usually postprandial
Caused by transient obstruction of the cystic duct by gallstone
Self-limited, generally < 6 hours, persistance in cholecystitis

48. ACUTE BILIARY DISEASE Dull ache and localized to RUQ or epigastrium
Radiate around the back to the right scapula
Nausea, vomiting, and low-grade fever are common
On examination, right upper quadrant tenderness, guarding, and Murphy's sign are diagnostic
Mild elevations in serum total bilirubin and alkaline phosphatase levels

49. ACUTE BILIARY DISEASE
Ultrasound evaluation of RUQ is the key diagnostic test
Finding of stones with gallbladder wall thickening, pericholecystic fluid, and sonographic Murphy's sign
Diabetic, with WBC over 15,000/mm3, are at particular risk for gangrenous cholecystitis

50. SMALL BOWEL OBSTRUCTION
In pediatric patients, intussusception, intestinal atresia, and meconium ileus
In adults, about 70% of cases are caused by postoperative adhesions and incarcerated hernias
Small bowel obstruction is characterized by sudden, sharp, periumbilical abdominal pain
Nausea and vomiting occur soon after onset of pain

51. SMALL BOWEL OBSTRUCTION
Frequent bilious emesis with epigastric pain is suggestive of high intestinal obstruction
Cramping periumbilical pain with infrequent feculent emesis is more typical of distal intestinal obstruction
Fever, tachycardia, and orthostatic hypotension
Abdominal distention
Diffusely tender to percussion and palpation, but peritoneal signs are absent

52. SMALL BOWEL OBSTRUCTION
Plain abdomen reveal dilated loops of small intestine with air-fluid levels
Decompressed distal small bowel and colon
CT is superior for establishing the diagnosis and location of intestinal obstruction

53. ACUTE DIVERTICULITIS 80% of affected patients are older than 50 years
Usually present with constant, dull, left lower quadrant pain and fever
Constipation or obstipation

54. ACUTE DIVERTICULITIS LLQ tenderness and mass
In severe cases, generalized peritonitis may be present
CT is reliable in confirming the diagnosis, with a sensitivity of 97%
Severity of diverticulitis, as determined by CT, is described using the Hinchey grading system

55. ACUTE PANCREATITIS Typically begins as acute pain in epigastrium
To back or left scapular region
Fever, anorexia, nausea, and vomiting are typical
Flank or periumbilical ecchymoses (Grey-Turner's or Cullen's sign)
Develop in setting of pancreatic necrosis with hemorrhage
Extremities are cool and cyanotic

56. ACUTE PANCREATITIS White blood cell counts of 12,000 to 20,000
Elevated serum and urine amylase levels are usually present within the first few hours of pain
Abdominal ultrasonography for identifying gallstones
CT is reserved for patients with severe or complicated pancreatitis

57. PERFORATED PEPTIC ULCER
Acutely with excruciating abdominal pain
Abdominal examination reveals peritonitis, with rebound tenderness, guarding, or abdominal muscular rigidity
Pneumoperitoneum is identified on an abdominal radiograph in 75% of patients

58. ACUTE MESENTERIC ISCHEMIA
More common in superior mesenteric artery than celiac or inferior mesenteric artery
Because of less acute angle
Acute mesenteric embolism, mesenteric thrombosis, and nonocclusive mesenteric ischemia each account for one third of cases
A mortality rate of 60% to 100%

59. ACUTE MESENTERIC ISCHEMIA
Epigastric and periumbilical pain out of proportion
Other symptoms - diarrhea, vomiting, bloating, and melena
Shock is present in about 25% of cases
CT is the best initial diagnostic test

60. ABDOMINAL COMPARTMENT SYNDROME
Elevated intra-abdominal pressure
In a patient who survives massive volume resuscitation
Resulting visceral or retroperitoneal edema
Elevated intra-abdominal pressure in turn compromises visceral perfusion
Kidney is particularly prone to underperfusion in this setting
Kidney failure may be the first sign of ACS