Special Topics in General Surgery

HEMATOLOGY/BLOOD PRODUCTS

Name common supplements that should be discontinued to avoid increased bleeding risk.

Ginko biloba, garlic, ginseng, omega-3, vitamin E, chondroitin, and saw palmetto.

How should one manage a Jehovah’s Witness patient with a low preoperative Hgb?

First evaluate the patient for cause: iron deficiency (i.e., possible GI malignancy), renal dysfunction, or folate/B12 deficiency. Once these causes of anemia are ruled out, the patient should be started on oral iron and recombinant erythropoietin.

What are the indications for RBC transfusion?

Evidence of active bleeding/hemorrhagic shock or generally Hgb <7 (Hgb <8 in patients with acute coronary syndromes). Previous guidelines to initiate transfusion for Hgb 10/Hct 30 have shown no benefit.

What is the most common acquired hypercoagulable disorder?

Smoking. Other common acquired causes: oral contraceptive pills, obesity, cancer, and antiphospholipid syndrome.

Three days after starting warfarin on a patient skin begins sloughing skin off their arms and legs. What is the most likely cause?

Warfarin induced skin necrosis may result if warfarin is started without first starting heparin. Protein C and S have shorter half-lives and decrease before the other vitamin-k dependent factors when warfarin is initiated. This leads to hypercoagulable state and skin necrosis. Treatment is heparin.

How do you treat a hemophiliac joint?

Do not aspirate. Elevate, range of motion exercises, and ice.

What is the most common location of a deep vein thrombosis?

Calf. However, iliofemoral DVTs are most likely to cause a pulmonary embolus. Left leg is twice as likely as right because the left iliac vein is compressed by the right iliac artery.

FLUIDS/ELECTROLYTES/NUTRITION

What are the indications for total parental nutrition (TPN)?

Enteral nutrition is always preferred over parenteral nutrition. TPN may be the only option for patients who require total bowel rest or do not have a functional GI tract (i.e., bowel obstruction, radiation enteritis, and congenital GI anomalies).

What does TPN formula usually consist of?

Water (30–40 mL/kg/day), protein (20% calories), fat (30% calories), dextrose (50% calories), trace minerals, vitamins, and electrolytes.

A patient presents for an elective procedure 3 months after thyroidectomy. What should you be cautious of?

A common cause of hypocalcemia is iatrogenic injury. Check for signs of hypocalcemia (perioral tingling/numbness, Chvostek’s sign, Trousseau’s sign, and prolonged QT on EKG). You may need to correct Mg before being able to correct Ca.

How can you assess a patient’s preoperative nutritional status?

Albumin (t^1/2 18 days), transferrin (t^1/2 8 days), and prealbumin (t^1/2 2 days) are all useful indicators of nutritional status. Albumin <2.5 and/or >20% weight loss in 6 months are strong risk factors for morbidity/mortality.

What is a respiratory quotient (RQ)?

RQ is a measurement of energy expenditure (ratio of CO₂ produced to O₂ consumed). RQ is important for patients who are ventilator dependent. RQ >1 (lipogenesis) indicates high carbohydrate and CO₂ buildup. Conversely, RQ <0.7 suggests fat oxidation (starvation) and carbohydrates should be increased.

What is the benefit of D51/2NS maintenance IV fluid?

5% dextrose stimulates insulin release, amino acid uptake, and protein synthesis. When given at 125 cc/hr it provides 150 g glucose/day.

ONCOLOGY

What is radiation enteritis?

GI toxicity may result when the radiation field includes GI structures (thorax, abdomen, or pelvis). Effects include early toxicity (i.e., diarrhea and nausea) and late toxicity (i.e., ulceration and stricture). Combining chemotherapy with radiation increases the risk of radiation enteritis.

What is the difference between a core needle biopsy (CNBx) and fine needle aspiration (FNA)?

CNBx gives architecture, FNA gives cytology.

Is higher energy radiation worse or better for the skin?

Better, maximal ionizing potential is not reached until deeper structures.

In which cases is it appropriate to resect a normal organ to prevent cancer?

(1) Colon (familial adenomatous polyposis), (2) Breast (BRCA I/II with strong family history), and (3) Thyroid (Ret protoncogene or MENIN gene with strong family history).

What are the guidelines for biopsy of an extremity sarcoma?

Excisional biopsy for lesions <4 cm and longitudinal incisional biopsy if >4 cm. The incisional biopsy is oriented longitudinally so that the scar can be easily resected after re-excision for margins.

THORACIC

What anatomy is relevant to thoracic outlet syndrome?

The thoracic outlet is the space between the clavicle and the first rib. The subclavian vein runs anterior to the anterior scalene, the subclavian artery and brachial plexus run between the middle/anterior scalenes. Patients can experience neurogenic, venous, or arterial manifestations of compression in this region.

What is a Pancoast tumor?

Superior pulmonary sulcus tumor. Invasion of the sympathetic chain leads to Horner’s syndrome (ptosis, miosis, and anhydrosis) or ulnar nerve symptoms (weakness of intrinsic hand muscles and pain/paresthesia of 4th and 5th digits).

What are the key features of chylothorax and its treatment?

The thoracic duct runs along the right side of the chest and crosses to the left side at T4–5 in order to drain into the left subclavian vein. Chylothorax is often due to iatrogenic injury of the thoracic duct. Management usually is conservative at first (chest tube, octreotide, and low fat diet). Surgical ligation can be performed if conservative measures fail.

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