Surgery Flashcards
AAA is defined as >
3cm. Definitely operate when > 5.5cm. Weigh risks and benefits when 4 - 5.5cm. Surveillance every 6 months to 3 years when 3 - 4 cm.
Why patients with AAA can get gross hematuria
Retroperitoneal rupture -> aortocaval fistula -> severe venous distension in bladder -> venous rupture in bladder
ABG in atelectasis
Respiratory alkalosis, hypocapnea and hypoxemia
Strategies to reduce post-op pulmonary complications
Stop smoking, control COPD, treat respiratory infection pre-op, spirometry, pain management and early mobilization.
Physical exam findings used to diagnose coma
Pupillary light reflex, EOM, corneal reflexes and posturing.
Mechanism of post-op ileus
Increased splanchnic nerve tone, local inflammatory mediator release and use of narcotic analgesics.
Metoclopramide mechanism of action
DA antagonist that causes LES contraction and gastric emptying.
Differential for an anterior mediastinal mass
“The terrible T’s”: teratoma, thymoma, thyroid neoplasm and terrible lymphoma.
AFP and beta-hCG in seminomas vs. non-seminomas
AFP is almost always normal in seminomas. The beta-hCG is variable in both types of tumors.
Area of the bladder most susceptible to rupture.
The dome. This was where the urachus originated in embryonic life and is an area of weaker tissue.
Definition of a massive hemothorax
> 1.5L
Muscles innervated by the axillary nerve
Deltoid and teres minor
Management of a stable patient with a contained appendiceal abscess for > 5 days.
IV abx, bowel rest and percutaneous drainage with elective appendectomy 6-8 weeks later.
When is surgery indicated for diverticulitis?
Fluid collection > 3cm can go for percutaneous drainage or surgery. Also, if symptoms are not controlled with bowel rest and antibiotics by day 5, surgery is indicated.
Pressure threshold to perform an escharotomy in a burn patient or fasciotomy in a patient with compartment syndrome
30mmHg
Management of a duodenal hematoma
Diagnose with contrast CT. Treat with NG suction and TPN. Most will resolve with this alone by 1-2 weeks.
Management of a first-time provoked DVT
Heparin to warfarin bridge 48-72 hours post-op. Warfarin for at least 3 months.
Physical exam for patients with trochanteric bursitis
Pain with direct pressure, resisted abduction and external rotation of the hip
Physical exam for patients with hip OA
Pain with internal rotation
Complications of the two different types of hip fractures
Intracapsular fractures have a higher chance of avascular necrosis. Extra capsular fractures have a greater need for implant devices.
How long can you delay repair of a hip fracture to medically stabilize you patient?
Up to 72 hours.
Danger space of head and neck infections
The retropharyngeal space is between the alar and prevertebral fascia, which drains directly into the mediastinum and can cause mediastinitis.
Ludwig’s angina
Infection of the submandibular space that begins in the floor of the mouth and spreads to the sublingual space
Major complication of parapharyngeal head and neck infections
Carotid sheath involvement
Risk factors for post-op pulmonary complications
Smoking, COPD, age > 50, thoracoabdominal surgery, surgery > 3 hours and poor general health.
Next step if incentive spirometry fails to improve post-op pulmonary function
CPAP
1 risk factor for development of aortic dissection
Hypertension
How long does it take for strictures to develop after ingestion of acid?
6-12 weeks
How long does it take for a diabetic to develop gastroparesis?
10 years
Treatment of acalculus cholecystitis
Antibiotics + percutaneous cholecystostomy until medical condition improves, then cholecystectomy.
Tetanus prophylaxis guidelines
3+ toxoid doses = repeat toxoid vaccine if clean or minor wound and last dose was 10+ years ago. If wound is dirty or severe, repeat toxoid vaccine if last dose was 5+ years ago.
Definition of massive hemoptysis and management of these patients. Management of patients with mild-moderate hemoptysis?
> 600mL/day or >100mL/hour. These patients get bronchoscopy with therapeutic interventions. If this doesn’t work move to pulmonary arteriography. If embolization doesn’t work, urgent surgical thoracotomy. Patients with mild or moderate hemoptysis can first have a CT chest.
SBO patients who go to the OR emergently
Those who do not improve with bowel rest, NG tube, pain control and correction of metabolic derangement and become unstable. Also those who develop signs/symptoms of strangulation.
SBO patients that can be managed conservatively
Stable patients can get a small-bowel follow-through study done if they have a partial obstruction and fail conservative management.
When should you be concerned about post-op adrenal suppression
When patients have been taking 20+ mg prednisone for > 3 weeks, have Cushingoid features and recently received etomidate.
Diagnosing pancreatic cancer in the head vs. tail and body?
Head = u/s. Tail/body = CT.
Common cause of nasal septum perforation after septoplasty
Septal hematoma expansion
Treatment for most cases of ischemic colitis
Bowel rest, fluids and IV antibiotics. Surgery if there is perforation.
Colonoscopy of patients with ischemic colitis
Sharply demarcated areas of hemorrhagic ulcerations and cyanotic mucosa.
Stress fracture management
Diagnose with x-ray. If x-rays are negative and suspicion is still high, may do MRI or bone scan. Manage with rest, pain control, hard-sole shoe and light activity. Plaster casting if conservative management fails. Surgery if the 5th metatarsal is involved.
Most commonly involved bone in stress fractures
2nd metatarsal
Management of a patient with a possible fat embolism
Confirm diagnosis with fat droplets in the urine or on fundoscopy 12-72 hours after surgery. Serial x-rays within 24-48 hours of onset of symptoms may show progressive pulmonary infiltrates. Treat with respiratory support.
Gold standard for evaluation of mesenteric ischemia
Mesenteric angiography
Labs in patients with Paget’s disease
Elevated alk phos and normal Ca and PO4
Cause of acute circulatory collapse in an intubated patient with PTX?
Increased intrathoracic pressure further decreases venous return to the right heart.
When is nasotracheal intubation contraindicated?
Apnea, hypopnea and basilar skull fractures.
When is needle cricothyroidotomy preferred to surgical cricothyroidotomy in an urgent airway situation?
Kids
When to convert cricothyroidotomy to a tracheostomy?
5-7 days, this will prevent tracheal stenosis
Normal respiratory quotient
Moles CO2 produced by fuel / moles O2 required to oxidize 1 mole of substrate. In normal individuals this = 0.8. 1.0 = too much carbohydrate, too much CO2 generation and it will be more difficult to wean a patient from a ventilator.
Timeline for post-op fevers
0-2 hours (immediate): prior trauma/infection, blood productions (1-6 hours), malignant hyperthermia.
1-7 days (acute): nosocomial infections (48 hours), SSI (GAS or C. perfringens), atelectasis (2-5 days), MI, PE, DVT
7-30 days (subacute): SSI (other organisms), catheter site infection, C. difficile, drug fever (anticonvulsants, allopurinol or antibiotics like beta-lactams and sulfonamides), DVT, PE
> 30 days (delayed): viral infection, SSI (indolent organisms)
Carboxyhemoglobin level when you are concerned about a patient’s airway
> 10%
Why are steroids contraindicated in severely burned patients
They are diabetogenic and immunosuppressive, increasing their risk for metabolic derangement and infections, respectively.
Benign breast lesion that does not fluctuate with the menstrual cycle like fibrocystic changes do.
Fibroadenoma
Causes of alveolar hypoventilation and respiratory acidosis
COPD, OSA, obesity hypoventilation syndrome, scoliosis, Myasthenia Gravis, Lambert Eaton, Guillan-Barre, anesthesia, narcotics, sedatives, brain stem lesion, stroke or meningitis.
Normal A-a gradient
Blood at the urethral meatus with a normal prostate exam and history of straddle injury.
Anterior urethral injury (anterior to urogenital diaphragm) is more common with blunt trauma or instrumentation.
Blood at the urethral meatus with difficulty voiding after an accident, high riding prostate and scrotal hematoma.
Posterior urethral injury is associate with pelvic fracture.
Most common causes of hypoparathyroidism
1 - surgical, #2 - autoimmune, #3 - DiGeorge syndrome, #4 - defective Ca-sensing receptor, #5 - infiltrative disease like hemochromatosis, Wilson’s and neck irradiation
Drugs that can cause vitamin D deficiency
P450 inducers like phenytoin, carbamazepine and rifampin
SIRS criteria
2 of the following:
T > 38.5C (101.3F) or 90
RR > 20
WBC > 12 or 10% bands
+source = sepsis
+oliguria, confusion = MODS
+hypotension = septic shock
Hypermetabolic changes that occur in the first week after a severe burn injury
Hyperglycemia, muscle wasting, protein loss and increased energy expenditure.
Most common causes of syringomyelia and Arnold-Chiari malformations?
Prior spinal cord injury
Why are more cardiologists doing catheterizations in the radial artery instead of femoral?
A puncture site above the inguinal ligament can cause a hematoma with retroperitoneal extension and cause hemodynamic instability.
How do diagnose a retroperitoneal hematoma
Non-contrast CT abdomen and pelvis
A patient presents with tachycardia, a new bundle branch block and a sternal fracture after an MVA. What is causing his symptoms?
Myocardial contusion
When are patients with a reperfused limb at significant risk for compartment syndrome
If the ischemia lasted greater than 4-6 hours, leading to significant soft tissue swelling and edema.
Interpretation of ABIs
- 3 or greater = calcified and non-compressible vessels, should prompt additional vascular studies (duplex u/s, CTA, MRA, angiography)
- 9 - 1.3 = normal
- 5 - 0.9 = moderate ischemia, consult vascular surgery
Structures at risk in supracondylar fracture of the humerus
Brachial artery and ulnar nerve
Management of post-CABG mediastintis
Diagnosed clinically by fever, tachycardia, chest pain, leukocytosis and sternal wound drainage.
Treated with surgical debridement and prolonged antibiotic therapy.
Management of post-CABG a-fib
Rate control with beta-blockers or amiodarone. Anticoagulation and cardioversion if lasting > 24 hours.
Post pericardotomy syndrome
Autoimmune fever, leukocytosis, tachycardia and chest pain a few weeks after the procedure.
Volume of blood required to cause symptoms in acute pericardial tamponade? Chronic?
Acute = 200mL
Chronic = 1-2L
Evaluation of hemoperitoneum in a stable vs. unstable patient involved in BLUNT trauma.
Unstable = FAST, then DPL if inconclusive
Stable = FAST, then CT abdomen/pelvis
***In penetrating trauma with signs of peritonitis or instability, all patients go directly to exploratory laparotomy.
Predisposing factors for emphysematous cholecystitis
Vascular compromise of the cystic artery, immunosuppression and gallstones
Management of emphysematous cholecystitis
Confirm with CT demonstrating air-fluid levels, gas in gallbladder wall and pneumobilia. Labs may show unconjugated hyperbilirubinemia due to clostridium-induced RBC hemolysis.
Treat with broad spectrum antibiotics and emergent cholecystectomy.
How to increase the FRC in the post-op period to prophylax against atelectasis
Have the patient in the upright position, incentive spirometry, chest physiotherapy and coughing.
Treatment of non-displaced scaphoid fractures? Displaced?
Non-displaced = wrist immobilization for 6-10 weeks
Displaced = ORIF
Work-up of a patient who suffers from a blunt deceleration injury to the chest
Screen for aortic injury with CXR. If equivocal, do chest CT and angiography.
Neurological risk when fixing a thoracic aortic aneurysm
Anterior cord syndrome from compromised blood flow from the artery of Adamkiewicz to the anterior spinal artery.
Risk factors for psoas abscess
HIV, diabetes, IVDU and Crohn’s disease
Diagnosis of psoas abscess
CT scan is required.
Diagnostic test of choice for meniscal injury
MRI
Most common peripheral artery aneurysm site
Popliteal
Definition of oliguria
Less than 400cc or 6cc/kg urine per day
Management of patients with new onset oliguria
1) Check Foley 2) If pre-renal azotemia is suspected (BUN:Cr > 20:1 and FeNa
Who gets ECRP?
Patients with gallstone pancreatitis who have cholangitis, visible common bile duct dilation/obstruction and increasing liver enzymes.
Lab value that points towards gallstone pancreatitis
ALT > 150
Management of patients with suspect ischemic colitis vs. mesenteric ischemia?
Ischemic Colitis: CT to determine need for surgery (perforation, extensive bowel damage). If surgery is not needed, patients can be managed with IV fluids, abx and colonoscopy to confirm the diagnosis (pale mucosa, petechial bleeding, bluish hemorrhagic nodules or cyanotic mucosa with hemorrhage).
Mesenteric ischemia: mesenteric angiography is gold standard for diagnosis. Treatment is supportive (fluids, abx, NG tube).
Differences in mesenteric vs. colonic ischemia
Small bowel has late hematochezia and is usually due to thromboembolism where ischemic colitis is typically due to hypotension and has early hematochezia.
Pre-op thresholds for packed red cell or platelet transfusion?
Hgb
How does DDAVP work?
Indirectly increases factor VIII levels by stimulating endothelial release of vWF.
Management of patients with walled off appendiceal abscess for > 5 days
IV abx, bowel rest and delayed appendectomy weeks later
When is bicarbonate given for acidosis
pH
Fevers, chills and deep abdominal pain in a patient with abdominal trauma and negative CT a few weeks ago.
Pancreatic injuries can be easily missed by early CT and turn into pseudocysts with retroperitoneal abscess later on.
Lab that can be used to track response to treatment for nasopharyngeal carcinoma
EBV titer
Middle 1/3 vs. distal 1/3 clavicular fracture management
Middle fractures get a brace, rest and ice.
Distal fractures get ORIF due to risk of non-union.
Treatment of anal fissures
Diet modification (increase fiber), stool softeners and topical anesthetic. If these fail you can do a lateral sphincterotomy.
Management of bleeding esophageal varices
If bleeding is rapid, sclerotherapy with octreotide will cause the bleeding to stop quickly. For elective procedures, variceal banding is typically done. Balloon tamponade is only done as a temporary measure to keep the patient from exsanguinating while awaiting higher level of care.
Management of dumping syndrome.
Since it is due to hyperosmolar food entering the duodenum, loss of intravascular volume and reflex sympathetic stimulation, patients should eat small meals, avoid simple carbohydrates, increase fiber and protein and abstain from drinking fluid during meals.
Aortoiliac occlusion resulting in claudication, hip pain and impotence
Leriche syndrome
Penetrating wound beneath which intercostal requires exploratory laparotomy in an unstable patient?
4th intercostal
Congenital umbilical hernia associations
Hypothyroidism, Beckwith-Wiedemann syndrome, African-American race, premature birth and Ehlers-Danlos.
When is surgery recommended for congenital periumbilical hernias?
After age 5 and > 1.5cm in diameter.
X-ray findings seen in patients with ileus, SBO and Oglivie’s
Ileus = gas-filled loops and air-fluid levels in large AND small bowel
SBO = area distal to obstruction is not distended
Ogilvie’s = massively dilated colon without dilation of small bowel.
Time from initial trauma that ARDS is typically seen
24-48 hours
