Surgery OSCE

Discuss Dx for Acute Cholecystitis
RUQ pain; first US look for gallstones, GBW>3mm thick; Pericholecystic fluid, US Murphy’s sign. If US equivocal do HIDA scan. If complications such as perf, abscess or cancer suspected do CT
Side 1
Side 2

Acute cholecystitis presenting signs and symptoms?
RUQ pain may radiate to R flank and back; sharp, stabbing, unremitting. N/V/F/C
DDx for acute cholecystitis
GERD; Peptic ulcer perforation; acute pancreatitis; cholangitis; choledocholithiasis; acute hepatitis; hepatic abscess; nephrolithiasis; pyelonephritis; RLL pneumonia.
Treatment plan for cholecystitis?
During first 5-7 days of sx, operative management perferred. After 7 days tx w/ fluids & antibiotics and readmit for surgery in 6 weeks. Surgery must decide lap vs. open. Open indicated in severe inflammation of Calot’s triangle or difficult antomy, risk of CBD high, malignant possibility.
Acute cholecystitis?
Inflammation of gallbladder of sudden onset 2/2 obstruction. 90% due to GS lodged in neck or cystic duct. ONly 10-20% of those w/ GS will get acute cholecystitis. Mortality <5% due to extremes of age, gangrenous or acalculous cholecystitis.
Differential Dx of Anterior Mediastinal mass?
6 Ts: Thymoma, thyroid, teratoma, testicular tumors, “Terrible” Lymphoma, paraThyroid tumor.
Dx byCXR and CT. 25% malignant, dx by invasion at surgery; Ass’d w/ Myasthenia gravis. Role of surgery is treatment +/- diagnostic.
Signs and sx of anterior mediastinal mass?
Cough; dyspnea; dysphagia; hoarseness; facial swelling (SVC syndrome)
How do you dx a substernal goiter?
Symptoms; CXR; CT scan; functional scans such as Iodine 131 uptake.
Tumor of brachial cleft cells: endoderm, ectoderm, mesoderm. 15% malignant. Surgery is diagnostic/tx
Usually large bulky mass, symptomatic. Tx: chemo/rad. Surgery is diagnostic
Can create mass anywhere in mediastinum. Sx: cough, fever, chest pain, wt. loss, SVC syndrome, chylothorax. Dx by CXR, CT, mediastinoscopy w/ node biopsy. Tx w/ chemo +/-rad. surg is diagnostic.
Mediastinal parathyroid?
Primary hyperparathyroidism. Will p/w increased PTH, serum Ca2+ and 24hr urine Ca2+. parathyroidectomy is tx.
Differential Dx when considering choledocholithiasis?
Choledocho; Mirizzi’s syndrome (physical obstruction of common hepatic ducts), pre-ampullary pancreatic mass (cancer, pseudocyst, duodenal diverticulum), gangrenous cholecystitis, liver abscess or hepatitis, Gilbert’s, gallstone panc, choledochol cyst, Ascaris (worm) infection
Management when suspecting choledocholithiasis?
Keep NPO, serial labs, Biliary imaging: MRCP, ERCP, lap/open chole +/- intraoperative cholangiogram
Surgical options for choledocholithiasis?
1) ERCP followed by elective lap-chole; 2) Lap chole w/ CBD exploration
Signs/sx of choledocholithiasis?
Many asymptomatic, RUQ pain/biliary colic; N/V, jaundice/scleral icterus, dark urine/clay-colored stools, increased LFTs. pain worse w/ food, radiates to back
Diagnosis of choledocholithiasis?
RUQ US; ERCP, MRCP, intraoperative cholangiogram
What will you find on US for choledocho?
Gallstones; 20-30% of CBD stones visualized, bile duct dilatation >8mm or 10% of age
ERCP vs MRCP for choledocho?
ERCP: dx & tx, sphincterotomy, 85-95% stones removed, 2-10% morbidity, 1%mortality. Comp: pancreatitis, bleeding, cholangitis, duodenal perf, stone recurrence. MRCP: >95% accurate for dx of choledocholithiasis, used if choledocho is unlikely but must be r/o
Lap CBD exploration?
Performed during lap chole, either trancystic duct approach or lap choledochotomy. T-tube placement.
Diagnosis of inguinal hernia?
Protuberant groin mass, manually reducible or may spontaneously reduce; pain, “pops out”, Perform physical upright and supine, exam w/ valsalva. Labs nonspecific, but if strangulated: leukocytosis, increased base deficit and lactate
Reduction of incarcerated inguinal hernias?
icepack; trendelenberg, relax the pt, gentle continuous pressure. Contraindications: erythema, induration, significant tenderness, leukocytosis
Surgical repair of inguinal hernia?
Lichtenstein: tension free mesh w/ low recurrence and risk of infection of 1%. Laparascopic: preperitoneal or transperitoneal. More serious complications (vascular or bladder)
Post operative complications of inguinal hernia repair?
Scrotal hematoma, bleeding, difficulty voiding, scrotal swelling, neuroma/neuritis, infection
Direct inguinal hernia?
Passes through Hasselbach’s triangle. medial to the inferior epigastric artery. Etiology: acquired weakness in floor of Hasselbach’s triangle.
Indirect inguinal hernia?
Sac lies anteromedial to cord. Exits through internal ring laternal to the inferior epigastric artery. Congenital patency of processus vaginalis. herniation through internal ring facilitated by weak inguinal floor.
Risk fx of inguinal hernias
Obesity, COPD, Pregnancy, Constipation, BPH, ascites. Males: females 7:1
Cholelithiasis: biliary colic or chronic cholecystitis; PUD; coronary artery disease; Diffuse esophageal spasm; zenker’s; Esophageal motor disorder; cacner; chronic panc.
Pathophysiology of GERD
LES fails either 1) chronically weak and hypotensive or 2) it opens too readily (transient LES relaxations). Manometry may ID resting dysf. showing pressure <6mm or short LES length. pH probe most accurate measurement. DeMeester score >14.72
Types of hiatal hernia:
type 1) sliding hernia may be reducible when upright 2)paraesophageal herniation of stomach w/ GE jnct at normal position 3) Paraesophageal herniation of stomach w/ GE jnct above normal 4) paraesophageal herniation of stomach and other abdominal contents, GE jnct above normal
Complications of GERD
Esophagitis: erosions or penetrating ulcer; barrett’s; esophageal stricture (or peptic); adenocarcinoma from Barrett’s; recurrent pneumonia, asthma; laryngitis, subglottic stricutre; esophageal perf. Incarceration can call gastric obstruction, chronic iron deficiency anemia, gastic pouch ulcer, space occupation/dyspnea
Management of GERD
Lifestyle: elevate HOB (4-6in), sleep on L side; wt loss; avoid bedtime snacks, chocolate, fatty food, cigs, EtOH. Med mgmt: PPIs, prokinetic agents
Indications for urgent surgery in GERD
Obstruction, Gastric necrosis; malignancy. Relative indications: paraesophageal hiatal hernia, complications of reflux (ulcerative peptic esophatitis, stricture, chornic ulcer), disabling sx (uncomplicated)
What is the gold standard surgery for GERD?
Nissen fundoplication. Most effective antireflux but highest risk of side effects. Other surgical options: Posterior partial wrap (Toupet), anterior partial wrap (Dor), Linx procedures w/ magnests around the GEJ, mucosal ablation for barrett’s
Signs/sx of Necrotizing fasciitis
Fever, tachycardia, hypotension, edema (outside involved area), pain out of proportion, blisters/bullae, crepitus/gas, leukocytosis, marked hyperglycemia, acidosis, “wooden” tissue. Can do finger test + frozen section: 2cm incision w/ local, lack of bleeding, dishwater fluid, probe along deep fascia. Section will show obliterative vasculitis, subQ necrosis
Imaging findings for nec fasc
CT: gas in tissues, fluid collections; MRI: soft tissue contrast, high sensitivity to detect soft tissue fluid. but don’t delay surgery for tests
Surgical tx of nec fasc
prompt and aggressive surgical debridement. All necrotic tissue should be radically debrided at initial surgery. Excise all tissue that gives way to moderate digital probing. Inpsect deep fascia and muscle w/ fluid and tissue for immediate gram stain and cx. 2nd look <24hrs later
What ABX do you use for nec fasc?
Gram (+): PCN or extended sepcturm PCN; Gram (-): aminoglycoside, carbapenam, cephalosporin; Anaerobe: Clindamycin. MRSA: Vancomycin. Cont. for 3 days after sx resolve. Also note that mortality is 100% w/ ABX tx alone.. must have surgery
How does clindamycin tx anaerobic nec fasc?
Inhibits bact. protein (toxin) synthesis. Efficacy not affected by innoculum size orstage of bact. growth. Facilitates phagocytosis. Suppresses synthesis of TNF-alpha.
Types of nec fasc?
Type 1: Mixed infection of aerobic + anaerobic; multibacterial symbiosis; ass’d w/ surgery, trauma, diabetes, peripheral vascular dz; Type 2: monobacterial usually GAS, MRSA, clostridium, otherwise healthy w/ h/o trauma.
Simple model to differentiate between necrotizing and non-necrotizing soft tissue infection.
WBC>15; Na<135: 90% sensitivity, 76% specificity.
Physiology and etiology of compartment syndrome?
Phys: increased pressure w/i an anatomical compartment –> decreased cap perfusion (~25-30cmH20). Etiology: fx, trauma, vascular injuries, hematoma, contusions, burns, tight dressings/casts, massive fluid resuscitation.
Sx of compartment syndrome
6 Ps: pain, pressure, paresthesias, paralysis, pale (pink) pulseless. If altererd: high level of suspicion warrants routine compartment pressure monitoring. Dx is clinical, but can measre intracompartment pressure w/ Wick/Slit catheter.
Tx of compartment sx?
Address cause; administer mannitol; fasciotomy and decompression: double anterolateral & posteromedial or single lateral. 11-15% mortality; 11-21% amputation; Nerve damage, bleeding, infection, dysfunction
Airway in penetrating trauma to neck:
10% w/ penetrating neck trauma present w/ airway loss, laryngotracheal injury, hematoma status, endotracheal intubation over bronchoscope best approach and ensures definitive airway. Avoid paralyzing agents that can lose muscle tone and worsened obstruction. Always be prepared for cricothyroidotomy.
Breathing and circulation in penetrating trauma to neck
Decompress any pneumothorax, control bleeding w/ digital pressure, balloon tamponade if necessary and IV fluids. Issues: airway may be compromised if large hematoma or extensive laryngotracheal injury, always prep for cricothyroidotomy, external compression and trendelenburg position to reduce risk of air embolism, spinal cord/CNS injuries.
Work-up of penetrating trauma to neck:
CT to evaluate for C-spine injuries; FAST-cardiac tamponade; CT only after hemodynamically stable; color flow doppler and angiogram.
What are the criteria for emergency operation for penetrating trauma to neck?
Hard signs: severe hypovolemic shock, active bleeding, pulsatile or growing hematoma, bubbling of air through wounds, mental status change, dyspnea, decreased peripheral pulse. Soft signs: pain on swallowing, small amount of hematemesis, hoarseness, slight hemoptysis, subQ emphysema in absense of pneumothorax. Note only 20% of penetrating neck injuries require surgery.
What are common mistakes in treating penetrating neck injury?
Sitting pt up –> air emboli, phramacological paralysis for eT intubation in pt w/ large hematoma, failure to evaluate for other injuries, missed spinal injury.
Indications of ABG?
Eval of ventilation by measuring partial pressures of O2 and Co2 and pH of arterial blood to assess pulm. function. Indicates status of gas exchange b/t lungs and blood. Base deficit is used as resuscitation endpoint.
Contraindications of ABG(8)?
infection of radial artery; negative Allen test; coagulation defects hemophilia; hx of clotting disorder; hx of arterial spasms following previous punctures; severe PVD; arterial grafts; arterial-venous shunts.
Complications of ABG (7)?
Discomfort; infection; hematoma; arteriospasm; thrombus formation; air or clotted blood emboli; anaphylaxis form local anesthetic.
Problems w/ integrity of ABG and possible erroneous results (3)?
1) Air bubbles; 2) Delay in cooling causing blood cells to continue to consume oxygen; 3) venous blood mixed in ABG sample.
What are abcesses?
localized infection of tissue marked by collection of pus surrounded by inflamed tissue. Strep, staph, enteric bact. or combination usually cause. Hot, tender and red and may rupture and spread if untreated –> bacteremia.
Contraindications of I&D outside of OR?
Extremely large abscesses, deep abscesses in sensitive areas, palmar space or deep plantar spaces are more likely to develop complications, nasolabial folds, pts at risk for endocarditis (need ABX)
Local anesthesia technique?
Cleanse skin; anesthesize top of wound by inserting 25 gauge needle under skin, draw back to ensure not in vessel and inject anesthetic into intradermal tissues.
Key points to I&D technique?
Make sure to anesthesize. Make incision (along skin tension lines) w/ scalpel over abscess. Take culture w/ swab. Irrigate wound w/ normal saline until effluent is clear. Pack w/ firm gauze. Skin margins must remain open until wound granulates from in to out. ABX usually not necessary, remove packing 2-3 days.
Indications of IV catheter insertion?
Administer IV fluids and/or meds
Contratidincation of IV catheter insertion?
Don’t use an extremity if there’s a fistula, shunt, amputation or past surgical procedure (i.e. mastectomy)
What are the common sites fo IV catheter insertion?
Antecubital- easy, fast but if pt bends arm solusion may not infuse. Hand- more painful. Wrist: more painful, mobile area may need splinting. Wrist to elbow: multiple choices, easy access.
Describe different sizes for IV cannulas/catheters?
Yellow (24G)- used in infants and children. Blue (22G)- in children and pt w/ small veins (elderly). Pink (20G) Standard size, useful for most infusions and blood. Green (18G) Better for blood. Grey (16G) Used for pts in shock- GI bleeds, trauma.
Key points to IV insertion?
Pt’s arm on pillow, prepare tubing, tourniquet, gloves. Cleanse area and allow to dry 30second. Hold catheter hub rotate 360 degrees. Anchor vein below needle at 10 degrees with hand above, after flashback lower to parallel to skin. Thread catheter to vein, release tourniquet, apply pressure above, retract needle, connect tubing. Cover w/ transparent dressing label w/ date time, gauge and initials on side of dressing.
What are the indications for NG tube placement (5)?
Decompress the stomach (obstruction, ileus), administer feedings and medications, lavage post toxic ingestion, dx GI bleeding, diaphragmentic hernias.
What are the contraindications for NG tube placement (4)?
Blunt or penetrating head injury w/ suspected basilar skull fracture; Facial fractures, suspected esophageal perforation (Boerhaave’s), GI surgery w/ orders contraindicating it.
What size NG tube do you use for adults vs children?
Adults #16-18. Children -Broselow tape.
Key points in NG tube insertion?
Explain procedure, ask about previous nasal surgery and test nostril patency, get water w/ straw. Have pt sit up or in reverse t-berg. Measure and mark with tape. Lubricate tip, insert and instruct pt to take small sips of water and swallow. Observe for signs of cyanosis. Secure w/ tape to nose. Use syringe to see if gastric contents come back. Send for CXR to confirm placement
Documentation of NG tube?
Indicate size, color, amount of drainage, complications, epistaxis, N/V. Daily documentation for feeding, amount, residual volumes (obtained every 4 hours) and recheck CXR if dislodgement suspected.
Indications for urinary catheter (4)?
Tx urinary retention and bladder outlet obstruction; For accurate UOP measurement in critically ill or post-op pt; Obtain urine specimen in pt who can’t void; Measure intra-abdominal pressures (for abdominal compartment syndrome).
Contraindications to urinary catheter?
Evidence of urethral trauma (Pelvic fx, straddle injuries or penetrating trauma)- signs and sx: blood at meatus, scrotal or perineal hematoma, high riding prostate all require retrograde urethrogram to document urethral integrity prior to insertion. Rectal and genital exam MUST be done before insertion.
Key points for foley insertion:
Make sure you prepare the sterile field. Take swabs out and lubricant and make sure tubing is connected. Test balloon. Hold labia or penis with non-dominant hand and maintain hand there until preparing to inflate balloon because now it’s not sterile. Use one swab per sweep from anterior to posterior. For males, one swab per circular motion, hold penis perpendicular to body. Females insert until you see urine and advance 2 more inches, in males insert all the way. Inflate balloon, tape catheter.
Types of suturing needles?
Curved: cutting (skin) vs. tapered (“round bodied” w/ shart wtip and smooth edges that are less traumatic using in deeper tissue). Straight: can be used w/o instruments.
How long should sutures be left in?
Face: 5-7d; Neck 7d; scalp 10d; trunk and upper extremities 10-14; lower extremities 14-21d
In what order do you draw blood?
Blood culture must always be first, then electrolyes, lFTs. Thent he next ones can be in any order: type and cross (pink), CBC (magenta), Coag (blue) Trops, ammonia (green, ammonia must be sent on ice).
General principles of Cervical collar placement?
All trauma pts assessed by physician must have spine evaluated. Clinical clearance by NEXUX low-risk criteria. If not met, pt must get radiologic evaluation. Moving pts w/ spinal precautions must be done via log-rolling.
NEXUS criteria for C-collar removal:
“NSAID”- Neurologically intact; Spinal midline cervical tenderness abscent; Alert (GCS>15) ; not Intoxicated; no Distracting injuries.
Contraindications to skin stapling?
Never be used on face or any surface that must bear weight or is subject to pressure.
General principle of wound dressing?
Keep wound tissue moist and surrounding tissue dry. Dressing functions to protect wound from contamination/trauma, provide compression if bleeding or swelling, apply medications, absorb drainage or debrided necrotic tissue, filling or pakcing wound, protecting skin surrounding wound.
What syringe/catheter should you use for irrigating a wound?
19G catheter to 35mL syringe delivers proper irrigation pressure and reduces risk of trauma and infection

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