📚 Internal Medicine Osce Clinical Skills Git Osce Cases Added Merged

📚 Lecture Overview

This summary covers key clinical gastroenterology skills for internal medicine OSCEs, focusing on systematic abdominal inspection, palpation and percussion of the liver and spleen, and ascites evaluation. It also details comprehensive history-taking frameworks for gastrointestinal bleeding, diarrhea, and inflammatory bowel disease (IBD). Mastering these physical exam techniques, diagnostic criteria, and clinical history templates is essential for clinical competency and OSCE success.

🎯 Key Concepts & Definitions

• Caput Medusa: Dilated paraumbilical veins radiating from the umbilicus, indicating portal hypertension (filling up-to-down) or inferior vena cava (IVC) obstruction (filling down-to-up).
• Grey Turner Sign: Ecchymosis or pigmentation of the flanks indicating retroperitoneal hemorrhage (e.g., acute hemorrhagic pancreatitis, ruptured splenic or aortic aneurysm).
• Cullen Sign: Periumbilical ecchymosis indicating intraperitoneal hemorrhage.
• Sister Mary Joseph Nodule: A palpable nodule at the umbilicus resulting from metastasis of an intra-abdominal malignancy (typically GI tumors).
• SAAG (Serum Ascites Albumin Gradient): A calculation used to distinguish portal hypertension ascites (SAAG $≥$ 1.1 g/dL) from non-portal hypertension causes (SAAG < 1.1 g/dL).
• Melena: Black, tarry, foul-smelling stool resulting from digested blood, typically originating from upper GI bleeding.
• Hematochezia: The passage of fresh, bright red blood per rectum, usually indicating lower GI bleeding or massive, rapid upper GI bleeding.
• Hypersplenism: A syndrome characterized by splenomegaly, cytopenia (mono- or pancytopenia) in the peripheral blood, compensatory hypercellular bone marrow, and correction of cytopenia after splenectomy.

📖 Main Content

1. Abdominal Inspection (The "First Spot")

To perform a correct inspection, always stand on the patient's right side and view the abdomen from the foot of the bed to evaluate symmetry. The patient must be exposed from the nipple to the knee.

• Contour & Flanks:
  • Symmetrical distension is caused by the 5Fs: Flatus (gases), Feces (constipation), Fetus (pregnancy), Fluid (ascites), or Fat (obesity).
  • Asymmetrical distension suggests hernia or organomegaly.
  • Flanks are full in ascites, but empty in obesity.
• Subcostal Angle:
  • Narrow (<70 degrees): Indicates cachexia or pigeon-shaped chest.
  • Wide (>110 degrees): Indicates obesity, ascites, COPD, or emphysema.
  • Unequal angles: Indicates visceroptosis (laxity of ligaments holding the liver/spleen), unilateral atelectasis, or unilateral emphysema.
• Divarication of Recti: Separation of the rectus abdominis muscles due to prolonged increased intra-abdominal pressure (e.g., ascites). Test this by asking the patient to perform a partial sit-up.
• Umbilicus Evaluation: Assess using the "2S, 2D, 2P + N" framework:
  • Site: Normally midway between the xiphisternum and symphysis pubis. Displaced upward (pelvic mass, pregnancy), downward (ascites, hepatomegaly), or laterally (scar, tumor).
  • Shape: Inverted (normal), everted (ascites, hepatosplenomegaly), slit-like (scar), or distorted (hernia).
  • Discharge: Pus (abscess), blood (endometriosis), urine/feces/bile (fistula), or fluid (bursting abdomen).
  • Dilated Veins (Caput Medusa): Perform the milking test to determine the direction of flow. Up-to-down filling = portal hypertension. Down-to-up filling = IVC obstruction.
  • Pigmentation: Cullen sign (intraperitoneal bleed).
  • Paraumbilical Hernia: Look for expansile impulse on cough.
  • Nodules: Sister Mary Joseph nodule.
• Epigastric Pulsations: Have the patient hold their breath. Palpate to determine the origin:
  • Hepatic (felt with thenar/hypothenar): Tricuspid regurgitation/stenosis, hemangioma, hypervascular HCC.
  • Aortic (felt under the flat hand): Aortic aneurysm, hyperdynamic circulation.
  • Right Ventricular (felt at the fingertips): RV hypertrophy, constrictive pericarditis.
• Skin Signs:
  • Striae: White (Striae Alba: old surgery, obesity); Red/Purple (Striae Rubra: Cushing syndrome, recent surgery).
  • Spider Naevi: Located above the nipple line; caused by liver cirrhosis and hyperthyroidism.
  • Purpura/Petechiae: Caused by liver cell failure. Petechiae (1 mm - 0.5 cm), Purpura (0.5 cm - 1 cm).

2. Palpation and Percussion Techniques

Liver Palpation

1. Stand on the patient's right side. Ensure exposure from nipple to knee.
2. Ask the patient to bend their knees to relax the abdominal muscles.
3. Start superficial palpation from the right iliac fossa (RIF) to build patient trust.
4. For deep palpation of the Right Lobe: Start at the RIF, move your hand inward and upward with the patient's inspiration. Repeat until you feel the liver edge or reach the costal margin.
5. For deep palpation of the Left Lobe: Start from the suprapubic area and move upward.
6. Hepatojugular Reflex: Press on the liver for 10-20 seconds. Normal is transient jugular vein congestion. No filling indicates IVC obstruction.
7. Tidal Percussion: Used to find the upper border of the liver (normally the 5th intercostal space in the midclavicular line). Percuss down from the 2nd ICS. Mark the point of dullness. Ask the patient to take a deep breath and hold it, then percuss again.
   • If resonant: Positive tidal percussion (indicates an infradiaphragmatic lesion like hepatomegaly).
   • If dull: Negative tidal percussion (indicates a supradiaphragmatic/lung lesion).
8. Normal Liver Span: 6-12 cm.

Spleen Palpation

• The spleen grows diagonally downward and medially due to restriction by the phrenicocolic ligament.
• Start palpating from the RIF, moving diagonally and upward toward the left costal margin.
• Try to feel the splenic notch on the medial border.

Spleen vs. Kidney Differentiation

3. Ascites Assessment

Classification by Volume

• Minimal Ascites (<500 ml): Detected only via ultrasound.
• Mild Ascites (500-1500 ml): Detected via Modified Shifting Dullness (patient rolls toward the examiner).
• Moderate Ascites (1500-5000 ml): Detected via Shifting Dullness.
• Massive Ascites (>5000 ml): Detected via Transmitted Thrill.

Shifting Dullness Technique

1. Percuss from the umbilicus out to the flanks with the patient supine.
2. Mark the point where the sound changes from resonant to dull.
3. Keep your finger on this point and have the patient turn to the opposite side.
4. Wait 10 seconds for fluid to gravitate.
5. Percuss again. If the area is now resonant, shifting dullness is positive.

Transmitted Thrill Technique

1. Patient lies supine.
2. Place the patient's or assistant's hand firmly on the abdominal midline (umbilicus) to block subcutaneous fat transmission.
3. Place your hand flat on one flank and tap/flick the opposite flank.
4. A felt impulse on the resting hand indicates a positive thrill.

4. Gastrointestinal Bleeding

History Taking Framework

• Personal Data: Age (alarm sign if >50), Gender, Occupation (farmers: Bilharziasis), Habits (smoking: ulcers; alcohol: varices).
• Analysis of Hematemesis: Frequency, amount, color (coffee ground = digested blood/peptic ulcer; fresh red = active bleeding/esophageal varices), presence of food particles (differentiates from hemoptysis).
• Associated Symptoms: Melena, abdominal pain (burning epigastric in ulcers), weight loss (malignancy), dysphagia.
• Sequelae: Syncope, ICU admission, transfusion history, hepatic encephalopathy signs (confusion, asterixis).
• Drug History: Ask about NSAIDs, corticosteroids, antiplatelets, and anticoagulants.

Differentiating Hematemesis vs. Hemoptysis

Obscure GI Bleeding

Defined as bleeding from the ligament of Treitz to the terminal ileum with negative upper endoscopy and colonoscopy.
- Overt: Patient sees active bleeding but endoscopies are negative.
- Occult: Bleeding is invisible; patient presents with iron-deficiency anemia and positive Fecal Occult Blood Test (FOBT).
- Diagnostic Tools: Capsule endoscopy or enteroscopy.

5. Diarrhea and Inflammatory Bowel Disease (IBD)

Diarrhea vs. Incontinence

• Diarrhea: >2 bowel movements/day, stool weight >200g/day, and loose/watery consistency.
• Incontinence: Loss of sphincter control (neurological history, pelvic surgery).

Pathophysiological Types of Diarrhea

• Osmotic: Caused by unabsorbed solutes (e.g., lactose intolerance, Mg antacids). Improves with fasting. High osmotic gap (>120).
• Secretory: Caused by active ion secretion (e.g., cholera, carcinoid). Does not improve with fasting. Low osmotic gap (<50).
• Inflammatory: Mucosal destruction with blood/mucus (e.g., IBD, dysentery).
• Motility: Rapid transit (e.g., hyperthyroidism, diabetic neuropathy).

Crohn's Disease vs. Ulcerative Colitis (UC)

Extra-intestinal Manifestations of IBD

• Skin: Erythema nodosum (tender red nodules on shins, more in Crohn's); Pyoderma gangrenosum (necrotic ulcers, more in UC).
• Joints: Axial sacroiliitis, peripheral arthritis.
• Liver: Primary Sclerosing Cholangitis (PSC) (strongly associated with UC).
• Eyes: Uveitis, episcleritis.

📊 Visual Learning

Diagram 1: Ascites Volume & Diagnostic Methods

Diagram 2: GI Bleeding Classifications

Diagram 3: Diarrhea Differentiation

💡 Important Points to Remember

• Always stand on the right side of the patient during abdominal examination.
• Normal Liver Span is 6-12 cm; determined by measuring the distance between the upper border (via tidal percussion) and lower border (via palpation) in the midclavicular line.
• Grey Turner's sign indicates retroperitoneal bleeding (flanks), whereas Cullen's sign indicates intraperitoneal bleeding (umbilicus). Both can be caused by acute hemorrhagic pancreatitis, ectopic pregnancy, ruptured HCC, ruptured splenic aneurysm, or ruptured spleen.
• Sister Mary Joseph nodule is a strong sign of metastatic GI malignancy.
• Portal hypertension presents with Caput Medusa filling up-to-down, while IVC obstruction presents with filling down-to-up (milking test).
• The spleen always grows inferomedially because its downward path is blocked by the phrenicocolic ligament.
• A shrunken liver indicates liver cirrhosis, whereas an irregular, firm, and tender liver strongly points to Hepatocellular Carcinoma (HCC) or metastasis.
• Fecal Calprotectin is a highly sensitive marker for intestinal inflammation (IBD), but it can be normal in small-bowel-isolated Crohn's disease.
• In patients with Ulcerative Colitis, the presence of a stricture is highly suspicious of colorectal malignancy, whereas in Crohn's, strictures are typically inflammatory/fibrotic.
• Mnemonic for symmetrical abdominal distension: The 5Fs (Flatus, Feces, Fetus, Fluid, Fat).

⚠️ Common Exam Questions

Common Exam Traps

• The "Black Stool" Trap: Examiners will present a patient with black stools and ask for the diagnosis. Students often jump to "Melena" without checking the drug history for Iron, Bismuth, or Charcoal intake. Use the Flask Test (stool in water; if it turns black, it is true melena).
• The "Paralytic Ileus" Peristalsis Trap: Examiners ask if visible peristalsis is seen in paralytic ileus. It is only seen in mechanical bowel obstruction; it is completely absent/silent in paralytic ileus.
• The "Obesity vs. Ascites" Flank Trap: Examiners will ask how to tell them apart on inspection. Full flanks = ascites; empty flanks = obesity.
• The "Hematochezia" Location Trap: Students are taught that hematochezia is strictly a lower GI bleed. However, massive, rapid upper GI bleeding (e.g., variceal rupture) can cause hematochezia due to blood acting as a rapid peristaltic irritant.
• The "Cautery in Colonoscopy" Trap: Examiners ask if electrical catheterization/cauterization can be used during colonoscopy. It is dangerous because colonic gases + electrical sparks can cause bowel explosion.

High-Yield MCQ & Short Answer Topics

• Spleen vs. Left Kidney: Differentiating features (ballottement, Traube's area percussion, and splenic notch are highly tested in OSCE vivas).
• SAAG Interpretation: SAAG $≥$ 1.1 indicates portal hypertension (cirrhosis, cardiac failure, Budd-Chiari); SAAG < 1.1 indicates non-portal hypertension (nephrotic syndrome, TB, peritoneal carcinomatosis).
• Forrest Criteria: Endoscopic classification of peptic ulcer bleeding to assess rebleeding risk.
• Alarm Signs for Endoscopy: Age >50, unexplained weight loss, anemia, blood loss, dysphagia.

📝 Quick Review Checklist

I can perform the milking test on abdominal veins to differentiate between portal hypertension and IVC obstruction.
I understand how to perform and interpret Tidal Percussion to find the upper border of the liver.
I can list the 7 diagnostic differences between an enlarged spleen and an enlarged left kidney.
I know the volume thresholds and physical exam methods for minimal, mild, moderate, and massive ascites.
I can calculate and interpret the Serum Ascites Albumin Gradient (SAAG) score.
I understand the key history-taking questions to ask a patient presenting with hematemesis, including the critical drug history (NSAIDs, steroids, anticoagulants).
I can distinguish between osmotic and secretory diarrhea using the fasting test and osmotic gap.
I can compare Crohn's disease and Ulcerative Colitis regarding anatomy, endoscopy, histology, and complications.