12. Surgical Diagnosis: Physical Signs, Laboratory, Imaging Devices; Interventions: Endoscopy, US/CT-Guided Interventions

I. Surgical Diagnostic Thinking and Physical Signs

Basic Surgical Diagnostic Sequence

Goal → Decide whether the patient needs observation, further investigation, urgent intervention or operation
Always start with clinical assessment; imaging confirms and localizes, but does not replace examination
In emergency → ABCDE first, then focused history/examination, labs, imaging and source control
Main surgical questions

Is there bleeding, perforation, ischemia, obstruction, sepsis or trauma?
Is the patient stable or unstable?
Is non-operative, interventional radiology/endoscopy or operative treatment needed?

History: Exam-Focused Points

Pain → Site, onset, migration, character, radiation, progression
GI symptoms → Vomiting, dysphagia, hematemesis, melena, hematochezia, constipation, diarrhea, jaundice
Urinary/gynecological symptoms when relevant
Fever, weight loss, anorexia, night sweats → Infection/malignancy suspicion
Previous operations, adhesions, hernias, scars, implanted devices
Drugs → Anticoagulants, antiplatelets, steroids, NSAIDs, immunosuppression
Comorbidities → Diabetes, cardiac/pulmonary disease, renal/liver disease, malignancy

General Inspection

General condition → Well, toxic, septic, shocked, cachectic
Color → Pallor, jaundice, cyanosis, flushing
Hydration/perfusion → Dry mucosa, cold extremities, sweating, capillary refill
Body habitus → Obesity, cachexia, sarcopenia
Scars → Previous operations, stomas, drains, hernia repairs
Abdomen → Distension, asymmetry, visible peristalsis, hernia, skin changes

Palpation

Tenderness → Localized, diffuse, superficial/deep
Defense/guarding → Voluntary or involuntary muscle contraction
Rebound tenderness / Blumberg sign → Peritoneal irritation
Rigidity → Board-like abdomen; diffuse peritonitis until proven otherwise
Mass → Site, size, shape, consistency, tenderness, mobility, pulsation, relation to skin/deep tissues
Organomegaly → Liver, spleen, enlarged gallbladder, kidney
Hernial orifices → Inguinal, femoral, umbilical, incisional; reducibility and strangulation signs

Percussion and Auscultation

Percussion

Tympany → Dilated bowel, ileus/obstruction
Dullness → Mass, full bladder, organomegaly, fluid
Shifting dullness/fluid wave → Ascites
Liver dullness absent → Free intraperitoneal air possible

Auscultation

Absent bowel sounds → Paralytic ileus, peritonitis, late obstruction
High-pitched/tinkling sounds → Mechanical bowel obstruction
Bruits → Aneurysm, vascular stenosis, arteriovenous fistula

Important Surgical Physical Signs

Sign	Meaning	Typical condition
Murphy sign	Inspiratory arrest during right subcostal palpation	Acute cholecystitis
McBurney tenderness	Tenderness at McBurney point	Acute appendicitis
Rovsing sign	Right lower quadrant pain during left lower quadrant palpation	Appendicitis/peritoneal irritation
Psoas sign	Pain with right hip extension or resisted flexion	Retrocecal appendicitis, psoas irritation
Obturator sign	Pain with flexed hip internal rotation	Pelvic appendicitis/abscess
Cullen sign	Periumbilical ecchymosis	Hemoperitoneum, severe pancreatitis
Grey-Turner sign	Flank ecchymosis	Retroperitoneal hemorrhage, severe pancreatitis
Courvoisier sign	Painless jaundice + palpable gallbladder	Distal biliary obstruction, pancreatic/periampullary cancer

II. Laboratory Diagnosis

Basic Surgical Laboratory Panel

Test	What it shows	Surgical relevance
CBC	WBC, Hb/Hct, platelets	Leukocytosis/infection; anemia/bleeding; thrombocytopenia/bleeding risk
CRP, ESR	Inflammation markers	Appendicitis, cholecystitis, abscess, postoperative infection; CRP trend useful
Electrolytes	Na, K, Cl, Ca, Mg	Vomiting, ileus, bowel obstruction, dehydration, arrhythmia risk
Renal function	Creatinine, urea/eGFR	Dehydration, shock, contrast risk, drug dosing
Liver tests	AST/ALT, ALP, GGT, bilirubin, albumin	Hepatitis, cholestasis, biliary obstruction, liver reserve
Amylase/lipase	Pancreatic enzyme elevation	Acute pancreatitis; lipase more specific
Coagulation	INR/PT, aPTT, fibrinogen	Bleeding risk, liver disease, anticoagulant effect, preoperative planning
Blood gas/lactate	Acidosis, hypoxia, lactate elevation	Shock, sepsis, bowel ischemia, severe bleeding
Blood group/screen	ABO/Rh and antibodies	Prepare transfusion for bleeding or major operation

Additional Tests by Clinical Suspicion

Urinalysis → UTI, stones, hematuria, dehydration
Pregnancy test in women of reproductive age → Ectopic pregnancy must not be missed
Cardiac markers/ECG → Chest pain, elderly acute abdomen, preoperative risk
Procalcitonin → Selected severe infection/sepsis; adjunct, not standalone
Blood cultures → Fever/sepsis before antibiotics if this does not delay treatment
Tumor markers → CEA, CA19-9, AFP, CA-125; adjunct for baseline/follow-up, not primary diagnosis alone

Important Interpretation Principles

Normal WBC/CRP does not exclude early appendicitis, ischemia or perforation
High lactate suggests tissue hypoperfusion/ischemia/sepsis but can be late or nonspecific
Trend is often more useful than one value → Hb fall, CRP rise, lactate clearance
Preoperative labs guide anesthesia risk, bleeding risk, renal contrast risk and antibiotic/drug dosing

III. Imaging Devices / Modalities

Plain X-Ray

Fast, cheap, available; limited soft tissue detail
Erect chest X-ray → Free subdiaphragmatic air in perforation
Abdominal X-ray → Bowel obstruction, ileus, volvulus signs, foreign body, radiopaque stones
Trauma/orthopedics → Fractures, dislocations, foreign bodies
Air-fluid levels + dilated loops → Mechanical bowel obstruction possible

Ultrasound (US)

First-line for many abdominal and superficial surgical problems
Advantages → No radiation, bedside possible, cheap, repeatable, Doppler vascular assessment
Limitations → Operator-dependent; difficult with obesity, bowel gas, severe pain
Typical uses

Gallstones, cholecystitis, biliary dilatation
Appendicitis in children/pregnancy or thin patients
Abdominal aortic aneurysm screening/rupture suspicion
FAST in trauma → Free intraperitoneal/pericardial fluid
Abscess, fluid collection, hernia, soft tissue infection
Doppler → DVT, arterial/venous flow, pseudoaneurysm

Computed Tomography (CT)

Cross-sectional imaging of choice in many surgical emergencies
Fast, high anatomical detail, good for intra-abdominal and thoracic pathology
CT with IV contrast → Inflammation, ischemia, bleeding, abscess, tumor staging, vascular assessment
Oral/rectal contrast can help selected leak/fistula/bowel questions, depending on urgency and protocol
Typical uses → Trauma, appendicitis, diverticulitis, perforation, bowel obstruction, abscess, pancreatitis complication, cancer staging
Limitations → Radiation, iodinated contrast allergy, renal risk, pregnancy considerations

Magnetic Resonance Imaging (MRI)

Best soft tissue contrast; no ionizing radiation
Slower, expensive, less available in emergency, contraindications with some implants
Typical uses → Liver lesions, rectal cancer staging, pelvic fistulas, soft tissue tumors
MRCP → Non-invasive biliary/pancreatic duct imaging; stones, strictures, obstruction
MRI useful in pregnancy when US is inconclusive and CT should be avoided if possible

Contrast Studies and Nuclear Medicine

Water-soluble swallow/meal/enema → Leak, perforation suspicion, obstruction, anastomosis check
Barium studies → Strictures, motility, fistulas; avoid if perforation risk because barium peritonitis is dangerous
Fistulography/sinography → Defines tract in selected fistulas
HIDA scan → Selected unclear cholecystitis/bile leak question
PET-CT → Cancer staging/restaging in selected tumors; not first-line emergency test

Choosing Imaging in Common Surgical Scenarios

Scenario	Often first / key imaging	Why
Acute abdomen, unclear cause	CT abdomen/pelvis with contrast if stable	Finds inflammation, perforation, ischemia, obstruction, abscess
Right upper quadrant pain/jaundice	US, then MRCP/CT/ERCP as needed	Gallstones and duct dilatation first; duct details by MRCP/ERCP
Suspected perforation	Erect CXR/CT	Free air; CT localizes source and complications
Bowel obstruction	Abdominal X-ray initially; CT for cause/ischemia	Level, cause, closed loop, strangulation signs
Major trauma	FAST if unstable; whole-body CT if stable	Rapid triage vs definitive injury mapping
Suspected abscess	US or CT	Diagnosis and possible image-guided drainage

IV. Interventions: Endoscopy and Image-Guided Procedures

Flexible Endoscopy: General Concept

Endoscopy = Direct intraluminal visualization with diagnostic and therapeutic possibilities
Advantages → Visual diagnosis, biopsy, hemostasis, foreign body removal, stenting, decompression
Preparation → Consent, fasting, anticoagulant plan, sedation/anesthesia assessment, bowel prep for colonoscopy
Complications → Bleeding, perforation, aspiration, sedation-related cardiorespiratory events, pancreatitis after ERCP

Upper GI Endoscopy (EGD / Gastroscopy)

Examines esophagus, stomach and duodenum
Indications → Dysphagia, dyspepsia with alarm signs, upper GI bleeding, anemia, ulcers, tumors, foreign body
Diagnostic → Visualization + biopsy, H. pylori testing, tumor diagnosis
Therapeutic → Hemostasis, variceal banding/sclerotherapy, dilatation, stent, PEG placement, foreign body removal

Colonoscopy and Lower GI Endoscopy

Examines colon and terminal ileum if intubated
Indications → Lower GI bleeding, colorectal cancer screening/diagnosis, IBD, unexplained anemia, polyp follow-up
Therapeutic → Polypectomy, biopsy, hemostasis, decompression of sigmoid volvulus/Ogilvie syndrome, stenting in selected obstruction
Contraindication/relative risk → Suspected perforation, severe unstable colitis, poor bowel prep, unstable patient

ERCP

ERCP: Endoscopic retrograde cholangiopancreatography
Now mainly therapeutic, not just diagnostic; MRCP/EUS often used for diagnosis first
Indications → Choledocholithiasis, cholangitis with obstruction, biliary stricture, bile leak, pancreatic duct problems
Therapeutic options → Sphincterotomy, stone extraction, balloon/basket retrieval, biliary/pancreatic stent, nasobiliary drainage
Complications → Pancreatitis, bleeding, perforation, cholangitis, sedation risk

Ultrasound-Guided Interventions

US guidance gives real-time needle visualization and avoids vessels/organs
Common uses

Abscess/fluid collection drainage → Liver, pelvis, superficial collections
Biopsy → Liver lesion, thyroid, lymph node, breast, soft tissue mass
Vascular access → Central venous catheter, arterial puncture, peripheral difficult access
Paracentesis → Ascites drainage/diagnosis
Thoracentesis and pleural drainage → Pleural effusion/empyema
Regional anesthesia/nerve blocks in perioperative care

CT-Guided Interventions

Useful for deep, retroperitoneal, thoracic or poorly US-visible targets
Excellent anatomical localization; no real-time continuous view unless CT fluoroscopy available
Common uses

Deep abscess drainage → Retroperitoneal, pelvic, intra-abdominal, peripancreatic collections
Biopsy → Retroperitoneal, lung, mediastinal, bone, pancreatic or deep abdominal mass
Percutaneous nephrostomy → Obstructive uropathy, infected obstructed kidney
Percutaneous transhepatic biliary drainage (PTBD) → Obstructive jaundice/cholangitis when ERCP impossible or failed
Drain placement after postoperative leak/abscess → Source control without immediate reoperation when suitable

Principles and Contraindications of Image-Guided Drainage/Biopsy

Indication must answer a clinical question or provide source control
Before procedure → Check coagulation, platelets, anticoagulants, allergies, renal function if contrast used
Plan route → Avoid bowel, vessels, pleura, solid organs if possible
Send samples → Culture, cytology, histology depending on indication
Contraindications/risks → Uncorrected coagulopathy, no safe access route, unstable patient needing operation, non-cooperative patient without anesthesia plan
Complications → Bleeding, infection, perforation, pneumothorax, bile/urine leak, tumor seeding rarely

Exam focus: Surgical diagnosis begins with inspection, palpation, percussion and auscultation; know peritonitis signs, named abdominal signs, basic labs, and when to use US, X-ray, CT, MRI/MRCP and contrast studies. For interventions, explain endoscopy, ERCP, US-guided drainage/biopsy/access and CT-guided deep drainage/biopsy/nephrostomy/PTBD.