Ch. 1 Pre- and Postop Care Flashcards
A 48 y/o woman develops constipation postop and self-medicates with milk of magnesia. She presents to clinic, at which time her serum electrolytes are checked, and she is noted to have an elevated serum magnesium level. Which of the following represents the earliest clinical indication of hypermagnesemia?
a. Loss of DTR
b. Flaccid paralysis
c. Respiratory arrest
d. Hypotension
e. Stupor
b. Flaccid paralysis
Five days after an uneventful cholecystectomy, an asymptomatic middle-aged woman is found to have a serum sodium level of 125 mEq/L. Which of the following is the most appropriate mgmt strategy for this patient?
a. Administration of hypertonic saline solution
b. Restriction of free water
c. Plasma ultrafiltration
d. Hemodialysis
e. Aggressive diuresis with furosemide
b. Restriction of free water
The initial, and often definitive, management of hyponatremia is free-water restriction. Acute severe hyponatremia sometimes occurs following elective surgical procedures due to a combination of appropriate stimulation of ADH.
Symptomatic hyponatremia, which occurs at serum sodium levels less than or equal to 120 mEq/L, can result in headache, seizures, coma, and signs of increased ICP –> require infusion of hypertonic saline
Rapid correction should be avoided so as not to cause central pontine myelinolysis.
A 50 y/o patient presents with symptomatic nephrolithiasis. He reports that he underwent a jejunoileal bypass for morbid obesity when he was 39. Which of the following is a complication of jejunoileal bypass?
a. Pseudohyperparathyroidism
b. Hyperuric aciduria
c. Hungry bone syndrome
d. Hyperoxaluria
e. Sporadic unicamerical bone cysts
d. Hyperoxaluria
Any pt who has lost much of the ileum is at high risk of developing enteric hyperoxaluria if the colon remains intact. Calcium oxalate stones can subsequently develop due to excessive absorption of oxalate from the colon.
Normally, fatty acids are absorbed by the terminal ileum, and calcium and oxalate combine to form an insoluble compound that is not absorbed. In the absence of the terminal ileum, unabsorbed fatty acids reach the colon, where they combine with calcium, leaving free oxalate to be absorbed.
Subsequently, the excess oxalate is excreted by the kidneys, promoting calcium oxalate stone formation.
Unicamerical bone cysts are benign and found in children.
Following surgery a patient develops oliguria. You believe the oliguria is due to hypovolemia, but you seek corroborative data before increasing IV fluids. Which of the following values supports the diagnosis of hypovolemia?
a. Urine sodium of 28 mEq/L
b. Urine chloride of 15 mEq/L
c. Fractional excretion of sodium less than 1
d. Urine/serum creatinine ratio of 20
e. Urine osmolality of 350 mOsm/kg
c. Fractional excretion of sodium less than 1
A FENa less than 1% supports a prerenal etiology for the pt’s oliguria. When oliguria occurs postop, it is important to differentiate between low output caused by physiologic response to intravascular hypovolemia and that caused by ATN. A FENa of less than 1% in an oliguric setting indicates aggressive sodium reclamation in the tubules. Values above this suggest a tubular injury such that Na cannot be appropriately reclaimed.
A 45 y/o woman with Crohn disease and a small intestinal fistula develops tetany during the 2nd week of parenteral nutrition. The laboratory findings include:
Na: 135
K: 3.2
Cl: 103
HCO3: 25
Ca: 8.2
Mg: 1.2
PO4: 2.4
Albumin: 2.4
An ABG sample reveals a pH of 7.42, PCO2 of 38 mm Hg, and PO2 of 84 mm Hg. Which of the following is the most likely cause of the patient’s tetany?
a. Hyperventilation
b. Hypocalcemia
c. Hypomagnesemia
d. Essential fatty acid deficiency
c. Hypomagnesemia
Magnesium deficiency is common in malnourished pts and pts with large GI fluid losses. The neuromuscular effects resemble those of calcium deficiency–namely, paresthesia, hyperreflexia, muscle spasm, and ultimately, tetany. The cardiac effects are more like those of hypercalcemia.
Hypomagnesemia also causes potassium wasting by the kidney. Many hospital pts with refractory hypocalcemia will be foundt o be magnesium deficient.
The serum calcium in this pt is normal when adjusted for the low albumin (add 0.8 mg/dL per 1 g/dL decrease in albumin).
Hypomagnesemia causes functional hypoparathyroidism, which can lower serum calcium and thus result in a combined defect.
A 25 year old woman is seen in the clinic three weeks following an appendectomy for acute appendicitis. The wound is well - healed. The pathology report identifies a 1.2 cm well-differentiated carcinoid tumor at the tip of the appendix, as well as acute appendicitis.
What would be the next most appropriate step in diagnosis?
a. CT-scan
b. MRI
c. Pet-scan
d. Ultrasonography
e. No further diagnostic studies
e. No further diagnostic studies
Well-differentiated carcinoid tumors, less than 2cm in diameter, that are incidentally found with a clear margin do not require additional diagnostic studies or workup.
A 24 year old woman presents to the office with a fever seven days following a laparoscopic appendectomy. She doesn’t feel well and complains of mild nausea. Vital signs include a blood pressure of 140/75 mmHg, a pulse of 102 per minute, respirations of 16 per minute, and a temperature of 38.5° C. On physical examination, the wound is well healed. There is tenderness in the RLQ without rebound. A digital rectal examination and bimanual examination of the pelvis suggest the presence of pelvic tenderness. There is no evidence of a palpable mass. The next most appropriate step is:
a. CT scan
b. Flat and upright films of the abdomen
c. Admit the patient for observation
d. Send the patient home with follow-up in one week
e. Intravenous antibiotics
f. Chest x-ray
a. CT scan
CT scan is the best way to assess for the presence of an intra abdominal abscess. If an abscess is documented, IV antibiotics should be started and a percutaneous drainage procedure, if possible, should be performed. Observation alone, whether at home or in the hospital is inadequate care.
You are discharging a 35 year old, otherwise healthy man following a laparoscopic appendectomy for an uncomplicated acute appendicitis. The patient has been ambulating and tolerated breakfast. On examination the wounds appear to be clean, without drainage. Vital signs include a blood pressure of 120/75 mmHg, pulse of 75 per minute, respirations of 12 per minute. Which of the following is the most appropriate advice for this patient on discharge?
a. Do not shower or bathe for three days
b. Come to the Emergency Department if you experience mild pain or constipation
c. Continue with a liquid diet until the 1st post op visit
d. A low grade fever is normal in the first 24-48 hrs after surgery
e. Redness and drainage from the incisions is normal
d. A low grade fever is normal in the first 24-48 hrs after surgery
A low grade (<38.0° C) fever is not uncommon after any surgical procedure due to the triggering of the stress response system. A higher fever or chills should be concerning. Patients should be alerted to potential complications such as wound infection characterized by erythema, increasing pain or purulent drainage. Constipation can be common while patients are taking narcotic pain medication. Showers are permitted beginning 24 hours after the procedure, once the skin has sealed. Submerging the incision underwater in a tub or pool is usually discouraged until sutures/staples are removed at the post-operative office visit.
A 24 year old man undergoes laparascopic appendectomy for a gangrenous, non perforated appendicitis. He received 1 gram of cefoxitan IV preoperatively. Postoperatively, he is awake and alert; he is tolerating a diet. On examination, the abdomen is not distended. Bowel sounds are present. There is generalized, mild abdominal tenderness to palpation. Vital signs include a blood pressure of 115/70 mmHg, a pulse of 85 per minute, respirations of 18 per minute, and a temperature of 37.5°C. Which of the following is the most appropriate plan for antibiotic management?
a. Continue for 48 hours after surgery
b. Continue for one week
c. Continue until the white blood cell count (WBC) normalizes
d. Antibiotics should be continued until intraoperative cultures have been reported
e. Antibiotics should not be continued post-operatively
e. Antibiotics should not be continued post-operatively
Antibiotics should be started within one hour prior to surgical incision to prevent wound infection. Following removal of the inflamed organ, there is no indication to continue antibiotics, certainly not for longer than 24 hours post-operatively.
A pt with a nonobstructing carcinoma of the sigmoid colon is being prepared for elective resection. Which of the following reduces the risk of postop infectious complications?
a. A single preop parenteral dose of abx effective against aerobes and anaerobes
b. Postop administration for 48 hrs of parenteral abx effective against aerobes and anaerobes
a. A single preop parenteral dose of abx effective against aerobes and anaerobes
No need to continue abx postop
A 75 y/o man with hx of MI 2 years ago, PVD with sx of claudication after walking half a block, HTN, and DM presents with a large ventral hernia. He wishes to have the hernia repaired. Which of the following is the most appropriate next step in his preop workup?
a. undergo ECG
b. undergo exercise stress test
c. undergo CABG prior to operative repair of his hernia
d. undergo persantine thallium stress test and echo
e. his hx of MI within 3 years is prohibitive for elective surgery. no further testing necessary
d. undergo persantine thallium stress test and echo
the pt should undergo persantine thallium stress testing followed by echo to assess his need for coronary angiogram with possible need for angioplasty, stenting, or surgical revascularization prior to repair of his hernia
although exercise stress testing is appropriate method, this pt’s functional status is limited by his PVD, and therefore pharmacologic stress test is preferred tx
An 18 y/o previously healthy man is placed on IV heparin after having a PE after ex lap for a small-bowel injury following a MVC. 5 days later, his platelet count is 90,000/mL and continues to fall over the next several days. The pt’s serum is positive for antibodies to the heparin-platelet factor complexes. Which of the following is the most appropriate next mgmt step?
a. Cessation of all anticoagulation therapy
b. Cessation of heparin and immediate institution of high-dose warfarin therapy
c. Cessation of heparin and institution of LMWH
d. Cessation of heparin and institution of lepirudin
e. Cessation of heparin and transfusion with platelets
d. Cessation of heparin and institution of lepirudin
The pt has HIT, which is a complication of heparin therapy, at both prophylactic and therapeutic doses. HIT is mediated by antibodes to the complexes formed by binding of heparin to platelet factor 4. In a previously unexposed patient, HIT typically manifests after 5 days.
Treatment of HIT consists of cessation of heparin (including LMWH), institution of a nonheparin anticoagulant such as a direct thrombin inhibitor (i.e. lepirudin, argatroban), and conversion to oral warfarin when appropriate.
Platelet transfusion is not indicated as HIT results in thrombotic rather than hemorrhagic complications.
A 65 y/o man undergoes a technically difficult abdominal-perineal resection for rectal cancer during which he receives 3 units of pRBCs. Four hours later, in the ICU, he is bleeding heavily from his perineal wound. Emergency coagulation studies reveal normal prothrombin, PT, and bleeding times. The fibrin degradation products are not elevated, but the serum fibrinogen content is depressed and the platelet count is 70,000/mL. Which of the following is the most likely cause of his bleeding?
a. Delayed blood transfusion rxn
b. AI fibrinolysis
c. A bleeding blood vessel in the surgical field
d. Factor VIII deficiency
e. Hypothermic coagulopathy
c. A bleeding blood vessel in the surgical field
A 68 y/o man is admitted to the coronary care unit with an acute MI. His postinfarction course is marked by CHF and intermittent hypotension. On the fourth day in hospital, he develops severe midabdominal pain. On exam, BP is 90/60 mm Hg and pulse is 110 bpm and regular, the abdomen is soft with mild generalized tenderness and distention. BS = hypoactive, stool Hematest is positive. Which of the following is the most appropriate next step in this pt’s mgmt?
a. Barium enema
b. Upper GI series
c. Angiography
d. U/S
e. Celiotomy
c. Angiography
In the absence of peritoneal signs, angiography is the diagnostic test of choice for acute mesenteric ischemia.
Pts with peritoneal signs should undergo emergent laparatomy. AMI may be difficult to dx. The condition should be suspected in pts with either systemic manifestations of arteriosclerotic vascular disease or low cardiac-output states associated with a sudden development of abdominal pain that is out of proportion to the physical findings.
Because of the risk of progression to small-bowel infarction, AMI = emergency and timely dx is essential
A 65 y/o man undergoes a low anterior resection for rectal cancer. On the fifth day in hospital, his exam shows a temperature of 102, BP of 150/90, pulse of 110 bpm and regular, and RR of 28 breaths per min. A CT scan of the abdomen reveals an abscess in the pelvis. Which of the following most accurately describes his present condition?
a. SIRS
b. Sepsis
c. Severe sepsis
d. Septic shock
e. Severe septic shock
b. Sepsis
- SIRS involves 2 or more of the following: T > 100, HR > 90, RR > 20, WBC count > 12,000 or <4000
- Sepsis = SIRS + documented infection
- Severe sepsis = SIRS + organ dysfunction or hypoperfusion (lactic acidosis, oliguria, AMS)
- Septic shock = sepsis + organ dysfunction + hypotension (systolic BP <90)
