Abdominal Pain¶
Chapter 16 | Part 2: Cardinal Manifestations and Presentation of Diseases · Part 2 – Cardinal Manifestations & Presentation · Chapter 16
Key Clinical Points¶
- Pain severity does not necessarily correlate with disease severity; mild pain can be catastrophic.
- Parietal peritoneal inflammation causes steady, aching pain transmitted by somatic nerves.
- Hollow viscus obstruction typically presents as colicky/intermittent pain (early) or steady pain (late).
- Vascular occlusion often presents as 'pain out of proportion' to physical findings.
- Referral from thoracic sources must be considered in all patients with upper abdominal pain.
- Immunocompromised patients may lack standard responses like fever or leukocytosis.
- Leukocytosis is not a reliable indicator of surgical necessity; counts >20,000/μL can occur in pancreatitis or cholecystitis.
- Functional disorders like IBS are diagnosed by clinical criteria after excluding structural abnormalities.
- Analgesics should not be withheld; they do not mask the underlying diagnosis.
- In cases of massive intraabdominal hemorrhage, there are no absolute contraindications to operation.
DEFINITION & OVERVIEW¶
• Core Challenge: Distinguishing conditions requiring urgent intervention from those managed nonoperatively. • Terminology Warning: The term 'acute surgical abdomen' is often misleading and should be avoided due to its inconsistent connotations. • Clinical Correlation: Pain severity eq disease severity; mild symptoms can mask severe pathology.
ETIOLOGY & PATHOPHYSIOLOGY¶
Mechanisms of Pain Origin¶
• Parietal Peritoneal Inflammation: ◦ Character: Steady and aching. ◦ Transmission: Somatic nerves. ◦ Intensity Factors: Dependent on type/amount of irritant (e.g., acidic juice > neutral feces; blood/urine only severe if sudden/massive). • Hollow Viscus Obstruction: ◦ Early Phase: Intermittent or colicky pain; less localized. ◦ Late Phase: Steady pain due to distension and loss of muscle tone. ◦ Small Bowel: Poorly localized → periumbilical or supraumbilical. ◦ Colonic Obstruction: Lower intensity → infraumbilical location → radiate to lumbar region. • Vascular Disturbances: ◦ Common Misconception: Not always sudden/catastrophic. ◦ Early Presentation (2-3 days): Mild continuous or cramping pain → caused by hyperperistalsis rather than peritoneal inflammation. ◦ Key Sign: 'Pain out of proportion' to physical findings (e.g., SMA occlusion). ◦ Aortic Aneurysm: Pain radiating to sacral region, flank, or genitalia → signal possible rupture. • Abdominal Wall Pain: ◦ Character: Constant and aching; exacerbated by movement, standing, and pressure. ◦ Differentiation: Muscle spasm in other body parts suggests myositis rather than intraabdominal disease. • Referred Pain: ◦ Thoracic Origin: Must be considered in all patients with upper abdominal pain (e.g., AMI, pneumonia). ◦ Distinction: Subscapular pain → extrahepatic biliary tree distention; Supraclavicular pain → pulmonary/pleuritic issues. ◦ Respiratory Behavior: Abdominal origin → persists through both respiratory phases; Referred origin → diminishes during inspiration. ◦ Palpation: Often does not accentuate, and in some cases, may relieve the pain of referred origin. • Metabolic Causes: ◦ Characteristics: Can mimic any intraabdominal disease. ◦ Specifics: Hyperlipidemia can coexist with pancreatitis; C1 esterase deficiency causes severe pain; Porphyria/Lead colic → hyperperistalsis (mimics obstruction). ◦ Uremia/Diabetes: Non-specific, shifting location and intensity. ◦ Black Widow Bite: Intense pain and rigidity of abdominal muscles and back. • Neurologic/Psychiatric Causes: ◦ Causalgic Pain: Burning character; limited to specific nerve distribution; triggered by touch or temperature change. ◦ Spinal Nerve/Root: Lancinating type; not related to food, distention, or respiration; often associated with hyperesthesia. • Toxic & Uncertain Mechanisms: ◦ Toxic: Lead poisoning, insect/animal envenomation, black widow bites, snake bites. ◦ Uncertain: Narcotic withdrawal, heat stroke.
Table 16-2: Some Important Causes of Abdominal Pain¶
• Pain Originating in the Abdomen: ◦ Parietal peritoneal inflammation (Bacterial contamination, Perforated appendix/viscus, PID, Chemical irritation, Perforated ulcer, Pancreatitis, Mittelschmerz, Mechanical obstruction of hollow viscera, Obstruction of small/large intestine, Obstruction of biliary tree, Obstruction of ureter, Appendicitis, Typhoid fever, Neutropenic enterocolitis/typhlitis). ◦ Vascular disturbances (Embolism or thrombosis, Vascular rupture, Pressure or torsional occlusion, Sickle cell anemia). ◦ Abdominal wall (Distortion/traction of mesentery, Trauma/infection of muscles, Distension of visceral surfaces [e.g., hemorrhage], Hepatic/renal capsules, Inflammation). • Pain Referred from Extraabdominal Source: ◦ Cardiothoracic (Pleurodynia, AMI, Myocarditis, endocarditis, Empyema pericarditis, CHF, Pneumonia, Pulmonary embolus, Pneumothorax, Esophageal disease). ◦ Genitalia (Torsion of the testis). • Metabolic Causes: ◦ Diabetes, Uremia, Hyperlipidemia, Hyperparathyroidism, Acute adrenal insufficiency, Familial Mediterranean fever, Porphyria, C1 esterase inhibitor deficiency. • Neurologic/Psychiatric Causes: ◦ Herpes zoster, Spinal cord or nerve root compression, Tabes dorsalis, Functional disorders, Causalgia, Psychiatric disorders, Radiculitis. • Toxic Causes: ◦ Lead poisoning, Insect or animal envenomation, Black widow spider bites, Snake bites. • Uncertain Mechanisms: ◦ Narcotic withdrawal, Heat stroke.
CLINICAL FEATURES¶
History Taking¶
• Core Components (Table 16-1): ◦ Age ◦ Time and mode of onset ◦ Pain characteristics ◦ Duration of symptoms ◦ Location and sites of radiation ◦ Associated symptoms and their relationship to the pain ◦ Nausea, emesis, and anorexia ◦ Diarrhea, constipation, or other changes in bowel habits ◦ Menstrual history • Clinical Pearls: ◦ Chronology is often more important than location. ◦ Analgesics should not be withheld; they do not obscure diagnosis. ◦ Pregnancy: Must consider altered anatomy and normal physiologic leukocytosis.
Physical Examination¶
• Inspection: Observe facies, position in bed, and respiratory activity. ◦ Note: Gentle examination is critical; aggressive palpation can induce protective muscle spasm. • Palpation & Rebound Tenderness: ◦ Technique: Avoid forceful rebound; use gentle percussion or ask the patient to cough to elicit true rebound. ◦ Risk: Aggressive palpation may mask a palpable gallbladder due to muscle spasm. • Auscultation: ◦ Reliability: Low. ◦ Findings: Peristaltic sounds can be present in strangulating obstruction; silent abdomen usually indicates severe chemical peritonitis. • Pelvic and Rectal Examination: ◦ Requirement: Mandatory for all patients with abdominal pain. ◦ Significance: Essential for detecting pelvic peritonitis where abdominal signs may be minimal.
DIFFERENTIAL DIAGNOSIS¶
Differential Diagnosis by Location (Table 16-3)¶
• Right Upper Quadrant: Cholecystitis, Cholangitis, Pancreatitis, Pneumonia/empyema, Pleurisy/pleurodynia, Subdiaphragmatic abscess, Hepatitis, Budd-Chiari syndrome. ◦ Epigastric: Peptic ulcer disease, Gastritis, GERD, Pancreatitis, Myocardial infarction, Pericarditis, Ruptured aortic aneurysm, Esophagitis. ◦ Left Upper Quadrant: Splenic infarct, Splenic rupture, Splenic abscess, Gastritis, Gastric ulcer, Pancreatitis, Subdiaphragmatic abscess. ◦ Right Lower Quadrant: Appendicitis, Salpingitis. ◦ Periumbilical: Early appendicitis, Gastroenteritis, Bowel obstruction, Ruptured aortic aneurysm. ◦ Diffuse Nonlocalized Pain: Gastroenteritis, Mesenteric ischemia, Bowel obstruction, Irritable bowel syndrome, Peritonitis, Diabetes, Malaria, Familial Mediterranean fever, Metabolic diseases, Psychiatric disease.
MANAGEMENT & TREATMENT¶
Analgesia¶
• Protocol: 1. Provide analgesics/narcotics promptly. 2. Do not withhold for diagnosis; they do not obscure clinical findings.
Surgical Indications¶
• Decision Logic: 1. Identify signs of peritonitis or obstruction. 2. Assess for vascular compromise (e.g., 'pain out of proportion'). 3. Evaluate for life-threatening conditions (e.g., ruptured aneurysm, perforated viscus).
Immunocompromised Management¶
• Approach: 1. Recognize that standard signs (fever, leukocytosis) may be absent. 2. Monitor for atypical infections (CMV, Mycobacteria, Protozoa, Fungi). 3. Perform serial examinations to monitor for progression of perforation.
KEY PEARLS & CLINICAL TRAPS¶
• Pain vs. Severity: Low pain eq low risk. • Somatic vs. Visceral: Somatic (peritoneal) is steady/aching; Visceral (hollow organ) is colicky/intermittent. • Vascular Warning: 'Pain out of proportion' to physical exam findings is a hallmark of vascular occlusion. • Thoracic Rule: Every patient with upper abdominal pain must be screened for myocardial infarction, pneumonia, or pulmonary embolism. • Examination Technique: Use cough for rebound; avoid aggressive palpation to prevent muscle spasm from masking underlying pathology (e.g., gallbladder). • Immunocompromised Patients: Lack of leukocytosis/fever does not rule out surgical emergencies like perforated viscus.
Reference Tables¶
TABLE 16-1 Some Key Components of the Patient’s History Age Time and mode of onset of the pain Pain characteristics…¶
Harrison's 22e, p.109
- Age
- Time and mode of onset of the pain
- Pain characteristics
- Duration of symptoms
- Location of pain and sites of radiation
- Associated symptoms and their relationship to the pain
- Nausea, emesis, and anorexia
- Diarrhea, constipation, or other changes in bowel habits
- Menstrual history
TABLE 16-2 Some Important Causes of Abdominal Pain Pain Originating in the Abdomen Parietal peritoneal inflammation¶
Harrison's 22e, p.110
| Pain Originating in the Abdomen | |
|---|---|
| Parietal peritoneal inflammation Bacterial contamination Perforated appendix or other perforated viscus Pelvic inflammatory disease Chemical irritation Perforated ulcer Pancreatitis Mittelschmerz Mechanical obstruction of hollow viscera Obstruction of the small or large intestine Obstruction of the biliary tree Obstruction of the ureter |
Vascular disturbances Embolism or thrombosis Vascular rupture Pressure or torsional occlusion Sickle cell anemia Abdominal wall Distortion or traction of mesentery Trauma or infection of muscles Distension of visceral surfaces, e.g., by hemorrhage Hepatic or renal capsules Inflammation Appendicitis Typhoid fever Neutropenic enterocolitis or “typhlitis” |
| Pain Referred from Extraabdominal Source | |
| Metabolic Causes | |
| Diabetes Uremia Hyperlipidemia Hyperparathyroidism |
Acute adrenal insufficiency Familial Mediterranean fever Porphyria C1 esterase inhibitor deficiency (angioneurotic edema) |
| Neurologic/Psychiatric Causes | |
| Toxic Causes | |
| Lead poisoning Insect or animal envenomation Black widow spider bites Snake bites |
|
| Uncertain Mechanisms |
TABLE 16-3 Differential Diagnoses of Abdominal Pain by Usual Location Right Upper Quadrant Cholecystitis Cholangitis…¶
Harrison's 22e, p.112
| Right Upper Quadrant | Epigastric | Left Upper Quadrant |
|---|---|---|
| Cholecystitis Cholangitis Pancreatitis Pneumonia/empyema Pleurisy/pleurodynia Subdiaphragmatic abscess Hepatitis Budd-Chiari syndrome |
Peptic ulcer disease Gastritis GERD Pancreatitis Myocardial infarction Pericarditis Ruptured aortic aneurysm Esophagitis |
Splenic infarct Splenic rupture Splenic abscess Gastritis Gastric ulcer Pancreatitis Subdiaphragmatic abscess |
| Right Lower Quadrant | Periumbilical | Left Lower Quadrant |
| Early appendicitis Gastroenteritis Bowel obstruction Ruptured aortic aneurysm |
||
| Diffuse Nonlocalized Pain | ||
| Gastroenteritis Mesenteric ischemia Bowel obstruction Irritable bowel syndrome Peritonitis Diabetes |
Malaria Familial Mediterranean fever Metabolic diseases Psychiatric disease |