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NBME Surgery Form 1 - Answers & Explanations

Updated: Nov 16, 2019

1) Needle-localized open biopsy • Percutaneous core biopsy, localization with needle and surgically sampling, is preferred for evaluation of microcalcifications • Fine-needle aspiration is inadequate as it may miss the cancer cells

2) Clostridium perfringens • Crepitus = gas-forming = clostridium

3) Lack of normal joint sensation • Neuropathic (Charcot) arthropathy

4) Avascular necrosis of the femoral head • Legg-Calvé-Perthes disease • Common in males between 5-8 years old

5) Low-dose heparin prophylaxis • Heparin is best choice for pre-surgical VTE prophylaxis because it has a short half-life (~45 mins) and is easily reversed with protamine sulfate

6) Cardiogenic shock • SOB, JVD, hypotension, hepatomegaly, ST elevation in anterior leads

7) Surgical decompression • Compartment syndrome

• Paresthesia and pain on passive stretch are early sxs

8) Fat embolism • Associated with long bone fractures and liposuction • Triad: Neurologic dysfunction, petechial rash (usually in axilla), respiratory distress (hypoxemia)

• Therapy is supportive

9) Melanoma • Subungual hematoma, unlike melanoma, will gradually clear as the nail heals

• Subungual hematoma will form a transverse groove across the surface as the nail heals

10) Testicular tumor • Young age, painless progressive enlargement over 8 months = cancer

• Hydrocele and Spermatocele both transilluminate • Epididymitis is painful

11) Appropriate in view of the medical necessity to remove the inflamed appendix

• Acutely inflamed appendix is a medical emergency and therefore doesn’t require consent

12) Ruptured spleen • Kehr sign: referred pain in shoulder due to irritants (eg, blood) in the peritoneal cavity • Kehr sign in the left shoulder is a classic sxs of a ruptured spleen

13) Rapid infusion of 0.9% saline

• Patient is unstable

14) Sphenopalatine artery • Sphenopalatine artery is the MCC of posterior nosebleeds • 90% of nosebleeds are anteriorly located at Kiesselbach’s plexus

15) Ovarian adenocarcinoma

• Nulligravid → uninterrupted menstrual cycles (follicular rupture and tissue damage) → ↑ risk of ovarian cancer

• Advanced ovarian cancer → peritoneal seeding and inflammation → ascites

• Meigs syndrome: triad of ovarian fibroma, ascites, and pleural effusion

16) Increase positive end-expiratory pressure

• Normal PO2 is between 80-10

• FiO2 and PEEP determine PO2; TV and RR determine CO2

17) Slipped capital femoral epiphysis

• Classically presents in teens/pre-teens that are obese or above 90th percentile in weight

18) Incision and drainage of the lesion

• Abscesses must be drained

19) Increased serum aldosterone concentration

• Renin increases on the affected side due to ↓ blood supply → ↑ aldosterone

• Blood supply to unaffected side is normal, so no need to release renin

20) Proctocolectomy with an ileoanal reservoir

• Prophylactic colectomy is the best long-term management in FAP because 100% of cases will eventually progress to CRC

• FAP patients should be screened with a colonoscopy every year starting at age 10-12

21) 15 L of lactated Ringer solution

• Parkland formula: 4 x weight in kg x % area

• 4 x 75 x 50 = 15000 ml = 15L

22) Epidural hematoma • The middle meningeal artery runs underneath the pterion, the weak region of the skull where the frontal, parietal, temporal, and sphenoid bones join together

• Traumatic blows to this area classically cause an epidural hematoma

23) Aortic arteriography

• Mild tenderness over the chest and a ‘somewhat’ widened mediastinum warrant an aortic arteriography

• If the patient had presented with “tearing chest pain radiating to the back” and a widened mediastinum following a MVC, then an immediate thoracotomy would be indicated

24) Carotid duplex ultrasonography

• B/L carotid bruits indicate stenosis in the carotids → compromised blood flow → cerebral ischemia → TIA

• Carotid U/S should be performed to determine the level of stenosis and the corresponding treatment

25) Determination of ankle brachial indices • ABI is the preferred initial step in diagnosis of peripheral arterial disease (PAD)

• Arterial U/S of the lower extremities is less sensitive and specific than ABI for the diagnosis of PAD

26) Vasoactive-inhibitory peptide-secreting tumor

• WDHA: Watery Diarrhea, Hypokalemia, Achlorhydria

• VIPoma is associated with MEN 1 syndrome

• Glucagonomas present with necrolytic migratory erythema, usually in the 5th decade of life

27) Femoral hernia • Protrudes through femoral canal lateral to the pubic tubercle and medial to the femoral vessels

28) Sliding hiatal hernia • Sliding hiatal hernias account for >90% of hiatal hernias • Associated with GERD and reflux esophagitis → ↑ risk of Barrett’s esophagus

29) Cholangitis, ascending • Charcot’s triad: jaundice, fever, RUQ pain • Reynolds pentad: Charcot’s triad, altered mental status, hypotension

• ↑ alkaline phosphatase and ↑ conjugated bilirubin

30) Laparotomy

• Presence of peritoneal signs in a patient with acute abdomen = indication for ex-lap

• Presence of involuntary guarding and rigidity is a contraindication for colonoscopy or sigmoidoscopy

31) Lymphoma

• Lymphatic obstruction (eg, neoplasm) → chylous ascites

32) Failure to suppress class II antigen recognition in the host

• Acute rejection has an onset of weeks to months • CD4 against MHC class II antigen

33) Intravenous administration of calcium gluconate • Hypocalcemia after parathyroidectomy is transient, but IV calcium should be given to protect the heart

34) Lactated Ringer solution

• Ranson’s criteria → pancreatitis

• Tx: fluids, analgesics, NPO

35) Initiation of dialysis

• ↑ urea nitrogen must be corrected pre-operatively because ↑ urea → platelet dysfunction → hemorrhage during surgery

• Demopressin (DDAVP) → ↑ release of factor VIII/vWf multimers, which can correct the coagulopathy in uremic patients

36) RBC 30/hpf (in sediment) • Hematuria, gross or microscopic, occurs in the majority of patients with symptomatic nephrolithiasis

37) Formation of antiplatelet antibodies

• Immune thrombocytopenia (ITP) causes destruction of platelets in the spleen due to anti-GpIIb/IIIa antibodies

• Labs: ↑ megakaryocytes, ↓ platelets

• Treatment: steroids, IVIG, rituximab, splenectomy for refractory cases

38) Water-soluble contrast upper gastrointestinal study • Rupture/perforation is a complication of esophagoscopy • Water-soluble (gastrograffin) contrast study can diagnose rupture

39) CT scan of the abdomen with contrast • Location of injury and gross hematuria suggest kidney injury • Contrast is really excreted and is used to visualize the collecting system

40) Squamous cell carcinoma • SCC → PTHrP → hypercalcemia

41) Aldosteronoma • Hyperaldosteronism → hypokalemia • Aldosterone escape → normal Na levels

42) Bladder outflow obstruction • Old male with mass in lower quadrant indicated BPH

43) Gastric bypass

• This patients has comorbidities due to morbid obesity (she is most likely bed-ridden → poor personal hygiene)

• BMI > 35 with a major comorbidity (eg, HTN, DM, etc.) qualifies for bariatric surgery; BMI > 40 qualifies without the presence of comorbidities

44) Heparin-induced thrombocytopenia • Antibody-heparin-PF4 complex activates platelets → thrombosis and thrombocytopenia

45) Thoracic spinal cord • Breast cancer metastasis to spinal cord • Decreased sensation below T4 indicates a thoracic location

46) Pseudomonas species

• Gram negative rod

47) Malignant pleural effusion • Past hx of cancer, respiratory distress, cyanotic, cachectic, decreased breath sounds, dullness to percussion • Pleural friction rub could be due to post-radiation fibrosis of the lungs

48) Atrial myxoma • Obstruction of mitral valve in diastole → diastolic murmur

• Changing of positions → movement of tumor → disappearance of murmur

• Cardiac myxoma produce IL-6 → fever and weight loss

49) Cytomegalovirus • Colitis in HIV + nuclear inclusion bodies = CMV • Presents with hematochezia, abdominal pain, weight loss, low-grade fever

50) High-output congesting heart failure • Circulatory overload → ↑ diastolic pressure in LV → pulmonary edema

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4 則留言

Hamza Tariq
Hamza Tariq

Can someone share form NBME 5 and 6 please


Lorenzo Carnio
Lorenzo Carnio

Any Updates on forms 5 and 6?


Jordan Abrams
Jordan Abrams

We're working on the explanations for the new NBME exams and hope to have them up soon!


Gracie Gustafson Willert
Gracie Gustafson Willert

can you do these for the new NBME 5 and 6?

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