Pretest - Pre & post operative care

Question 1

58yo woman develops constipation postoperatively 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 hypermagneesemia?

a. loss of DTRs
b. flaccid paralysis
c. respiratory arrest
d. hypotension
e. stupor

Answer 1

A

high Mg = generalized neuromuscular depression
1) decreased DTRs

(VERY HIGH levels of Mg)

• progressive weakness –> flaccid quadriplegia –> respiratory arrest
• hypotention
• alterne MS –> somnolence –> coma

Question 2

5d after an uneventful cholecystectomy, an asymptomatic middle-aged woman is found to have a serum sodium level of 125. which of the following is the most appropriate management strategy for this pt?

a. admnistration of hypertonic saline solution
b. restriction of free water
c. plasma ultrafiltration
d. hemodialysis
e. aggressive diuresis with furosemide

Answer 2

B
, likely due to appropriate stiimulation of ADH and accidental admiistration of excess free water in the first few postop days
but she has no sxs
–> woudld be HA, seizures, coma, signs of increased intracranial pressure

1) free water restriction

Question 3

a 50yo pt presents with symptomatic nephrolithiasis. he reports that he underwent a jejunoileeal bypasss ffor 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 unicameral bone cysts

Answer 3

D.
normally, FAs are absorbed by the terminal ileum, and Ca + oxalate into insoluble compound thatis not absorbed.

1) loss of ileum + intact colon –> risk of enteric hyperoxaluria –> due to excess absorption of oxalate from colon
2) unabsorbed FAs and bile acids in colon –> increased oxalate uptake by the colon

–> leading to absorbed oxalate excreted by the kidneys –> leading to kidney stones

hungry bone syndrome –> after parathyroidectomy for high PTH - chronically high levels then sudden cessation –> leads bones to take up a lot of Ca = reflextive hypocalcemia

Question 4

Following surgery a pt develops oliguria. you believe the oliguria is due to hypovolemia, but you seek corroborative data before increasing intravenous fluids. which of the following values supports the diagnosis of hypovolemia?

a. urine Na of 28
b. urine Cl of 15
c. fractional excretion of Na <1
d. urine / serum creatinine ratio of 20
e. urine osmolality of 350

Answer 4

C

intense re-absorption of water

hypovolemia

1) FeNa <1 –> prerenal
2) urine sodium <20
3) urine osmolality > 500
4) urine / serum creatinine > 20
5) BUN/creatinine > 20

Question 5

a 45yo woman with Crohn disease and a small intestinal fistula develops tetany during the second week of parenteral nutrition. the lab findings include:
Na 135
K 3.2
Cl 103
HCO3 25
Ca 8.2
Mg 1.2
PO4 2.4
Albumin 2.4
an arterial blood gas sample reveals a H of 7.42, PCO2 of 38, and PO2 of 84. which of the following is the most likely cause of the pt's tetany
a. hyperventilation
b. hypocalcemia
c. hypomagnesemia
d. essential fattty acid deficiency
e. focal seizure

Answer 5

C

hyperventilation –> low PCO2
hypomagnesemia –> <1.0
hypocalcemia –> <8

corrected Ca = 8.2 + 0.8 (4-2.4) = 8.2 + 0.8(1.6) = 9.5

hypomagnesemia is common in pts with malnutrition / large GI fluid loss
SIMILAR to hypocalcemia
- paresthesia, hyperreflexia, muscle spasm, tetany
–> prolonged QT & PR; ST segment depression, flattened / inverted p waves; torsade de pointes

hypocalcemia
- prolonged QT, T wave inversion, heart block

Question 6

a pt with nonobstructing carcinoma of the sigmoid colon is being prepared for elective resection. which of the following reduces the risk of postoperative infectious complications?

a. a single preoperative parenteral dose of antibiotic effective against aerobes and anaerobes
b. avoidance of oral antibiotics to prevent emergence of C. difficile
c. postoperative administration for 48h of parenteral Abs effective against aerobes and anaerobes.
d. postoperative administration of parenteral antibiotics against aerobe and anaerobes until the pt’s intravenous lines and all other draines are removed
e. redosing of antibiotics in the OR if the case lasts for >2h

Answer 6

A

unasyn = ampicillin + sulbactam

within an hour of the procedure

Can redose, but A is definitely a better answer

Question 7

a 75yo man with a hx of myocardial infarction 2y ago, peripheral vascular disease with sxs of claudication after walking half a block, HTna dn 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 preoperatve w/up?

a. he should undergo a ECG
b. he should undergo an exercise stress test
c. he should undergo coronary artery bypass prior to oeprative repair of his ventral heria
d. he should undergo a persantine thallium stress test and echocardiography
e. his hx of a MI within 3y is prohibitive for elective surgery. no further testing is necessary

Answer 7

D

b/c surgery is a big stress on the heart

to assess for need for coronary angiogram +/- angioplasty

can’t do a regular stress test b/c of his PAD –> so do a drug stress test instead

MI within the last 6mo would be the concern

Question 8

a previously healthy 55yo man undergoes elective R hemicolectomy for a stage I (T2N0M0) cancer of the cecum. his postoperative ileus is somewhat prolonged, and on the 5th postoperative day his NG tube is still in place. PE reveals diminished skin turgot, dry mucous membranes, and orthostatic hypotension. pertinent lab values are as follows:
arterial blood gases - pH 7.56, PCO2 50, PO2 85
Serum electrolytes Na 132, K 3.1, Cl 80, HCO3 42
Urine electrolytes Na 2, K 5 Cl 66

What is the pt’s acid-base abnormality?

a. uncompensated metabolic alkalosis
b. respiratory acidosis with metabolic compensation
c. combined metabolic and respiratory alkalosis
d. metabolic alkalosis with respiratory compensation
e. mixed respiratory acidosis and respiratory alkalosis

Answer 8

D –> PCO2 is high; it’s not adequately compensated.

PCO2 would be normal if it was completely uncompensated

very dehydrated

alkalosis, metabolic
PCO2 = 1.5 (42) + 8 = 63+ 8 = 71 –> 69-73

Question 9

a 52yo man with gastric outlet obstruction secondary to a duodenal ulcer presents with hyppochloremic, hypokalemic metabolic alkalosis. which of the following is the most appropriate therapy for this pt?

a. infusion of 0.9% NaCl with supplemental KCl until clinical signs of volume depletion are eliminated
b. infusion of isotonic (0.15N) HCl via a central venous catheter
c. clamping the NG tube to prevent further acid losses
d. administration of acetazolamide to promode renal excretion of bicarbonate
e. intubation and controlled hypoventilation on a volume cycles ventilator to further increase PCO2

Answer 9

A

likely due to excess vomiting
loss of hypertonic fluid

signifiant volume depletion –> contraction alkalosis, with excessive salt and water retension –> increased tubular aximum for bicarb reabsorption

Tx = correction of volume depletion = correction of bicarbonate –> via excretion of excess

Question 10

23yo woman is brought tot he ED from a half-way house, where she apparently swallowed a handful of pills. The pt complains of SOB and tinnitus, but refuses to identify the pills she ingested. pertinent lab values are as follows:
arterial blood gases: pH 7.45, PCO2 12, PO2 126
serum electrolytes: Na 138, K 4.8, Cl 102, HCO3 8

an overdose of which of the following drugs would be most likely to cause the acid-base disturbance in this pt?

a. phenoformin
b. aspirin
c. barbituates
d. methanol
e. diazepam (Valium)

Answer 10

B

tinnitus –> aspirin
metabolic acidosis (accumulation of organic acids)
+ respiratory alkalosis (direct stimulation of respiratory center with tachypnea)

Question 11

an 18yo previously healthy man is placed on IV heparin after having a PE after exploratory laparotomy for a small bowel injury following a motor vehicle collision. 5d later, his plt count is 90,000 and continues to fall over the next several days. the pt’s serum is positive for Abs to the heparin-plt factor complexes. which of teh following is the most appropriate next management step?

a. cessation of all anticoagulattion therapy
b. cessation of heparin and immediate institution of hihg-dose warfarin therapy
c. cessatin of heparin and institution of low-molecular weight heparin
d. cessation of heparin and institution of lepirudin
e. cessation of heparin and tranfusion with plts

Answer 11

D

Type 2 HIT –> stop heparin; add “gator” (agatroban)

warfarin should not be started until Plt > 100,000

Plt transfusion started at Plt ,10,000
–> b/c HIT results in thrombotic (NOT hemorrhagic complications)

Question 12

65yo man undergoes a technically difficult abdominal perineal resection for a rectal cancer during which he receives 3 U of pRBCs. 4h later, in the ICU, he is bleeding heavily from his perineal wound. Emergency coagulation studies reveal normal prothrombin, partial thromboplastin, and bleeding times. the fibrin degradation are not elevated, but the serum fibrinogen content is depressed and the plt count is 70,000. which of the following is the most likely cause of his bleeding?

a. delayed blood transfusion rn
b. autoimmune fibrinolysis
c. a bleeding blood vessel in the surgical field
d. factor 8 deficiency
e. hypothermic coagulopathy

Answer 12

C

low fibrinogen, low plts –> likely because of loss of blood

Postop bleeding
transfusion rxn = fever, apprehension, HA

a 65yo man would have known about bleeding d/o beforehand, and would have caused a problem in the OR (& have worse coag numbers)

Question 13

a 78yo man with a history of coronary artery disease and an asympomatic reducible inguinal hernia requests an elective hernia repair. which of the following would be a valid reason for delaying the proposed surgery?

a. coronary artery bypass 3 mo earlier.
b. a history of cigarette smoking
c. jugular venous distension
d. hypertenion
e. HLD

Answer 13

C

Contraindications

• likely fluid overloaded –> possible heart failure (JVD, S3, ectopicbeats)
• risk to the heart up to mo after recent MI.
• age > 70y
• emergency surgery

(POD 3) most perioperative infartcts occur postoperatively when the third-space fluids return to the circulation –> increased preload, myocardial O2 consumption

Question 14

a 68yo man is admitted to the coronary care unit with an acute MI. his postinfarction course is marked by CHF and intermittent hypotension. on the 4th day in hospital, he develops severe midabdominal pain. on PE, BP 90/60 and pulse is 110 beats per minute and regular; the abdomen is soft with mild generalized tenderness and distention. BS are hypoactive, stool Hematest is positive. which of the following is the most appropriate next step in this pt’s management?

a. barium enema
b. upper GI series
c. angiography
d. ultrasonography
e. celiotomy

Answer 14

C

ischemic colitis - d/t lack of perfusion from MI

• systemic manifestations of arteriosclerotic vascular dz
• low CO states + abdominal pain OUT OF PROPORTION to physical exam
• -> embolic occlusion / thrombosis of SMA, low perfusion

Studies

1) CT scan
2) + Angiography - in the absence of peritoneal signs
- late: lactic acidosis / leukocytosis
- NOT Upper GI/ US

Treatment
1) Peritoneal signs –> emergent laparotomy

Risks
- small bowel infarction

Question 15

30yo woman in her last trimester of pregnancy suddenly develops massive swelling of the L LE. which of the following would be the most appropriate workup and treatment at this time?

a. venography and heparin
b. duplex US and heparin
c. duplex US, heparin, and venal caval filter
d. duplex US, heparin, warfarin
e. impedance plethysomography

Answer 15

B

need both diagnostic study + heparin

DO NOT give warfarin to pregnant women —> b/c can cross placenta –> spontaneous abortion, birth defect

Question 16

20yo woman with a FHx of von Willebrand disease is found to have an aPTT of 78 (nml = 32) on routine testing prior to cholecystectomy. Further investigation reveals a PT of 13 (nml = 12), a plt count of 350,000 and an abnormal bleeding time. which of the following should be administered in the perioperative period?

a. Factor 8
b. Plts
c. Vit K
d. Aminocaproic acid
e. Desmopressin (DDAVP)

Answer 16

E

PT = factor 7
aPTT = all other factors 

likely factor 8 or von willebrand deficiency

VWF deficiency

• Type I = AD; decreased vWF
• Type II = variably inherited; defective vWF
• Type III - AR; absence vWF
• -> superficial bleeding (mucosal, petechiae, epistaxis, menorrhagia)

Studies- depressed ristocetin cofactor assay

Tx : DDAVP

1) activate receptors that cause release of vWF; shortens bleeding time in Type I & II.
2) wvl prevents inactivation of Factor 8 –> normalized Factor 8

Question 17

65yo man undergoes a low anterior resection for rectal cancer. on the 5th day in the hospital, his PE shows a temp of 39C (102F) Bp 150/90, pulse of 110 BPM and regular, and RR of 28. 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

Answer 17

B

SIRS

1) high temp
2) tachycardia
3) tachypnic
4) leuks? probably also high

Sepsis = SIRS + documented infection

but not hypotensive –> NO SHOCK

Question 18

a victim of blunt abdominal trauma has splenic and liver lacerations as well as an unstable pelvic fracture. he is hypotensive and tachycardic with a HR of 150 despite receiving 2L of crystalloid en route to the hosiptal. he was intubated prior to arrivaal due ot declining mental status. he is taken emergently to the OR for exploratory laparotomy and external fixation for his pelvic fracture. which of the following is the best resuscitative strategy?

a. infusion of another L of crystalloid
b. infusion of 500mL of 5% albumin
c. infusion of pRBCs + fresh-frozen plasma + plts as indicated by the PT and plt counts in laboratory values
d. infusion of pRBCs and early administration of fresh-frozen plasma and plts prior to return of laboratory values
e. infusion of pRBCs and vitK

Answer 18

D

in distributive shock
it would take too long to get lab values

Class D heorrhagi shock = loss of >40% of circulating blood volume

large amt of banked blood transfusion

• dilutional thrombocytopenia
• deficiencies in factors 5 & 8

DO NOT

• give excessive crystalloid infusion - will dilute further
• VitK takes too long

Question 19

62yo woman undergoes a pancreaticoduodenectomy for a pancreatic head cancer. a jejunostomy is placed to facilitate nutritional repletion as she is expected to have a prolonged recovery. which is the best method for delivering postop nutrition?

a. institution of enteral feeding via the jejunostomy tube after return of bowel function as evidenced by passage of flatus or a BM
b. institution of enteral feeding via the jejunostomy tube within 24h postop
c. institution of supplemental enteral feeding via the jejunostomy tube only if oral intake is inadequate after return of bowel fx
d. institution of combo of immediate trophic (15mL/h) eneral feeds via the jejunostomy tube and parenteral nutrition to provide total nutritional support
e. coplete nutritional support with TPN

Answer 19

B

TPN + tube feeds?

–> early enteral nutrition in pts who have prolonged recovery after surgery

Question 20

65yo woman has a life-threatening PE 5d after following removal of a uterine malignancy. she is immediately heparinized and maintained in good therapeutic range for the next 3d, then passes gross blood from her vagina and develops tachycardia, hypotension, and oliguria. following resuscitation, an abdominal CT scan reveals a major retroperitoneal hematoma. which of the following is the best next step in management?

a. immediately reverse heparin by a calculated dose of protamine and placed a venal caval filter (eg a Greenfield filter)
b. reverse heparin with protamine, explore and evacuate the hematoma, and ligate the vena cava below the renal veins
c. switch to low-ose heparin
d. stop heparin, and observe closely
e. stop heparin, give fresh-frozen plasma, and begin warfarin

Answer 20

A

you can’t give prothrombotics –> b/c of “life-threatening PE”

you can’t give anticoagulation –> b/c she could continue to bleed into the hematoma; she’s clearly in shock now

• protamine is an anticoagulant
  1) antidote to heparin (1mg protamine / 100 U heparin) –> when hemorrhage begins shortly after bolus of heparin
  2) based on t1/2 of heparin (90 min)
  3) given only 1/2 of calculated circulating heparin to be reduced.

if you ligate the veins, you’ll get blood building up in the legs - BAD
SHOULD not try to explore retroperitoneum for bleed

indications for IVC filter placement

• failure / complication of anticoagulation
• knwon free-floating venous clot
• prior hx of PE

Question 21

71yo man develops dysphagia for both solids and liquids and weight loss of 60lb over the past 6mo. he undergoes endoscopy, demonstrating a distal esophageal lesion and biopsies are consistent with squamous cell carcinoma. he is scheduled for neoadjuvant chemoradiation followed by an esophagectomy. preoperative, he is started on TPN, given his severe manutrition reflected by an albumin <1. which of the following is most likely to be a concern initially in starting TPN in this pt?

a. hyperkalemia
b. hypermagnesemia
c. hypoglycemia
d. hypophosphatemia
e. hypochloremia

Answer 21

D

he is perpetually starved –> shift electrolytes to extracellular space to maintain adequate serum conc.

concerns about refeeding synrdrome –> increased insulin; shift electrolytes intracellularly

• hypophosphatemia + increased need for phosphorus for ATP production & glucose metabolism
• hypomagnesemia
• hypokalemia
• hyperglycemia
• hyperchloremic acidosis
• volume overload with resultant CHF..

Tx

• replete TPN slowly
• replete Mg, K, PO4
• limit dextrose infusions to prevent complications of refeeding.

Question 22

an elderly diabetic woman with chronic steroid-dependent bronchospasm has an ileocolectomy for a perforated cecum. she is taken to the ICU, intubated and is maintained on broad-spectrum antibiotics, renal dose dopamine, and rapid steroid taper. on postop day 2, she develops a fever of 39.2C (102.5F), hypotension, lethargy, and lab values remarkable for hypoglycemia dn hyperkalemia. which of teh following is the most likely explanation for her deterioration?

a. sepsis
b. hypovolemia
c. adrenal insufficiency
d. acute tubular necrosis
e. diabetic ketoacidosis

Answer 22

C

ADRENAL INSUFFICIENCY - addison’s crisis
- in pts with severe stress, infection trauma

sxs

• changing mental status
• increased temp
• CV collapse
• hypoglycemia
• hyperkalemia

Tx

• dexamethasone for steroid replacement
• volume resuscitation

Question 23

a cirrhotic pt with abnormal coagulation studies due to hepatic synthetic dysfunction requies an urgent cholecystectomy. a transfusion of FFP is planned to minize the risk of bleeding due to surgery. what is the optimal timing of this transfusioN?

a. the day before surgery
b. the night before surgery
c. on call to surgery
d. intraoperatively
e. in the recovery room

Answer 23

C

coagulation factors need time?

t1/2 of the most stable clotting factor (factor 8) = 4-6h
–> ensures that transfusion is complete prior to incision, with circulating factors to cover operative & immediate postoperative period.

Question 24

on postop day 5, an otherwise healthy 55yo man recovering from a partial hepatectomy is noted to have a fever of 38.6C (101.5F). which of the following is the most common nosocomial infection postop?

a. wound infection
b. pneumonia
c. urinary tract infection
d. intra-abdominal abscess
e. IV catheter-related infection

Answer 24

C

1) most common nosocomial infection = UTI
2) pneumonia, wound infection, intra-abdominal abscess, catheter-related bloodstream infections

Question 25

10d after an exploratory laparotomy and lysis of adhesions, a patient, who previously underwent a low anterior resection for rectal cancer followed by postoperataive chemoradiation, is noted to have success draining from the wound. she appears to have adequate source control - she is afebrile with a normal WBC. the output from the fistula is approx 150cc per day. which of the following factors is most likely to prevent closure of the enterocutaneous fistula?

a. previous radiation
b. previous chemotherapy
c. recent surgery
d. history of malignancy
e. >100cc output per day

Answer 25

A

Risk factors for fistula

• foreign body
• radiation
• inflammation
• epitheliaization fo tract
• neoplasm
• distal obstruction
• steroids

Question 26

26yo man is resuscitated with pRBCs following a MVA complicated by a fractured pelvis and resultant hemorrhage. a few h later, the pt becomes hypotensive with a normal CVP, oliguric, and febrile. upon examination, the pt is noted to have profuse oozing of blood from his IV sites. which of the following is the most likely diagnosis?

a. hypovolemic shock
b. acute adrenal insufficiency
c. Gra neg bacteremia
d. transfusion reaction
e. ureteral obstruction

Answer 26

D

hypotension + DIC

Acute transfusion reaction –> complement-mediated RBC destruction

• fever, chills, pain, redness along infused vein
• oozing from IV sites, respiratory distress, anxiety
• hypotension, oliguria

Question 27

16yo adolescent boy with a x of severe hemophilia A is undergoing an elective inguinal hernia repair. which of the following is the best option for preventing or treating a bleeding complication in the setting of this dz?

a. fresh-frozen plasma
b. combo of desmopressin and fresh-frozen plasma
c. ddavp
d. combo of e-aminocaproic acid and desmopressin
e. factor 9 concentrate

Answer 27

D

b/c would give desmopressin normally to hemophiliac–> increased von willebrand = stabilized factor 8

+ e-aminocaproic acid = inhibitor of fibrinolysis

Question 28

59yo man is planning to undergo a coronary artery bypass. he has OA and consumes NSAIDs for pain. which of the following si the most appropriate treatment prior to surgery to minimize his risk of bleeding from his NSAID use?

a. begin vit K 1wk prior to surgery
b. give FFP few hours before surgery
c. stop the NSAIDs 1w prior to surgery
d. stop the NSAIDs 3-4d prior to surgery
e. stop the NSAIDs the day before surgery

Answer 28

D

platelets = 7d lifespan. NSAIDs cuase a reversible defect that lasts 3-4d

Question 29

63yo man undergoes a partial gastrectomy with Billroth II reconstruction for intractable peptic ulcer disease. he presents several months post-op with a megaloblastic anemia. which of the following is the best treatment for this surgical complication?

a. transfusion with 1U of pRBCs
b. oral iron supplementation
c. oral vitB12 supplementation
d. IV vit B12 (cyanocobalamin) supplementation
e. oral folate supplementation

Answer 29

D

megaloblastic anemia –> vitB12 or folate

antrum produces gastrin / gases & intrinsic factor for vitB12

do IV instead of oral b/c not reliable –> administered q3-4 months, for life

Question 30

52yo woman undergoes a sigmoid resection with primary anastomosis for recurrent diverticulitis. she returns to the ED 10d later with L flank pain and decreased urine output. Lab exam is significant for WBC of 20,000. She undergoes a CT scan that demonstrates new L hydronephrosis, but no evidence of an intra-abdominal abscess. which of the following is the most appropriate next step in management?

a. intravenous pyelogram
b. IV antibiotics and repeat CT in 1w
c. administration of IV methylene blue
d. no further management if UA is negative for hematuria
e. immediate re-exploration

Answer 30

A. diagnostic imaging with pyelogram / nuclear medicine.

? damage to ureters –> obstruction, with backflow into kidneys

common causes of iatrogenic ureteral injuries

• gynecologic surgeries
• colorectal surgery

Question 31

23 yo woman undergoes total thyroidectomy for carcinoma of the thyroid gland. on the second postoperative day, she begins to complain of a tingling sensation in her hands. she appears quite anxious and later complains of muscle cramps. which fo the following is the most appropriate initial management strategy?

a. 10mL of 10% magnesium sulfate IV
b. oral vit D
c. 100 ug of Synthroid
d. continous infusion of Ca gluconate
e. oral Ca gluconate

Answer 31

D

IV –> for severe hypocalcemia (muscle spasm). oral is okay for mild sxs (usually just tingling)

most postop = Mg problem (esp. + TPN)
post-thyroidectomy = Ca problem

Question 32

65yo man has an enterocutaneous fistula originating in the jejunum secondary to inflammatory bowel disease. which of the following would be the most appropriate fluid for replacement of his enteric losses?

a. D5W
b. 3% normal saline
c. ringer lactate solution
d. 0.9% sodium chloride
e. 6% sodium bicarbonate solution

Answer 32

C

loss mostly with diarrhea

bild and fluids in small intestine –> electrolyte content similar to Ringer lactate

Question 33

62yo man is suffering from arrhythmias on the night of his tripe coronary bypass. Potassium has been administered. his urine output is 20-30mL. which of the following medications counteracts the effects of potassium without reducing the serum potassium level?

a. sodium polystyrene sulfonate (kayexalate)
b. sodium bicarbonate
c. 50% dextrose
d. Calcium gluconate
e. insulin

Answer 33

D. calcium gluconate - causes shift; counteracts myocardial effect of hyperkalemia. First-line in hyperkalemia

–> 480-720mL in the day –> oliguria.

poor perfusion –> low flow to kidneys - prerenal AKI

Decreases serum K

• Kayexalate - cation exchange resin (Na out, K in)
• Na-bicarbonate - increased srum pH (K in)
• glucose - glycogen synthesis (K in)
• insulin (K in)

Question 34

an in-hospital workup of a 78yo hypertensive, mildly asthmatic man who is receiving chemotherapy for colon cancer reveals symptomatic gallstones. preoperative lab results are notable for a Hct of 24% and UA with 18-25 WBCs and Gram neg bacteria. on call to the OR, the pt receives IV penicillin. his abdomen is shaved in the OR. an open cholecystectomy is performed and despite a lack of indications, the common bile duct is explored. the wound is closed primariliy with a Penrose drain exiting a separate stab wound. on post-op day 3, the pt develops a wound infection. which of the following changes in the care of this pt could have decreased the chance of a post-op wound infection

a. increasing the length of the pre-operative hospital stay to prophylactically treat the asthma with steroids
b. treating the UTI prior to surgery
c. shaving the abdomen the night prior to surgery
d. continuing the prophylactic antibiotics for 3 post-op days
e. using a closed drainage system brought out through the operative incision

Answer 34

B.

definitely okay to give Abs on call to OR, to shave that day

DO NOT continue abs that long. –> C diff.

risks of postoperative wound infection

• prior infection
• Pt factors = age, obesity, steroid dependent, comorbidities
• long pt prehospital stay
• open drainage systems
• exiting the skin at or near the operative incision
• long OR time

Improved healing = optimized:

• nutritional status
• tissue perfusion
• O2 delivery

Question 35

72yo man undergoes a subtotal colectomy for a cecal perforation due to a sigmoid colon obstruction he has had a prolonged recovery and has been on TPN for 2w postoperatively. after regaining bowel function, he experienced significant diarrhea. exam of his abdominal wound demonstrates minimal granulation tissue. he complains that he has lost his taste for food. he also has increased hair loss and a new perioral pustular rash. which of the following deficiencies does he most likely have?

a. zinc
b. selenium
c. molybdenum
d. chromium
e. thiamine

Answer 35

A

lost taste for food –> zinc, low

Question 36

12 yo boy with a femur fracture after a MVA undergoes operative repair. after induction of anaesthesia, he develops a fever of 40C (104F), shaking rigors, and blood-tinged urine. which of the following is the best treatment option?

a. alkalinization of the urine, administration of mannitol, and continuation with the procedure
b. administration of dantrolene sodium and contiuation with the procedure
c. administration of dantrolene sodium and termination of the procedure
d. administration of IV steroids and an antihistamine agent with continuation of the procedure
e. administration of IV steroids and an antihistamine agent with termination of procedure

Answer 36

C. malignant hyperthermia w/ induction of anaesthesia (succinylcholine / halothane-basd inhalational anaesthetics)

take off anaesthesia + dantrolene

Question 37

24yo Jehovah’s Witness who was in a high-speed motorcycle collision undergoes emergent splenectomy. his estimated blood loss was 1500mL. which of the following strategies should be employed for his resuscitation?

a. vasopressors should be primarily utilized for maintenance of his BP
b. synthetic colloids should be administered as the primary resuscitation fluid in a 3:1 ratio to replace the volume of blood lost.
c. 0.9% normal saline should be administered in a 1:1 ratio to replace the volume of blood lost.
d. 0.45% normal saline should be administered in a 3:1 ratio to replace the volume of blood lost
e. lactated Ringer solution should be administered in a ratio of 3:1 to replace the blood lost

Answer 37

E

lost a lot of blood and products –> would usually give albumin / colloids or blood

Question 38

a 60kg, 53yo with no significant medical problems undergoes lysis of adhesions for a small bowel obstruction. postoperatively, he has high nasogastric output and low urine output. what is the most appropriate management of his fluids?

a. infusion of D5 0.45% normal saline at 100mL/h
b. infusion of D5 0.9% normal saline at 100mL/h
c. infusion of D5 lactated Ringer at 100mL/h
d. replacement of NG tube losses with lactated Ringer in addition to maintenance fluids
e. replacement of NG tube losses with 0.45% normal saline with 20 mEq/L of KCl in addition to maintenance fluids

Answer 38

D

60*0.6 = 36

4mL/kg/h for first 10kg, 2mL/kg/h for next 10kg, 1mL/kg/h for each additional 10kg

60kg * 4mL * 1h = 100mL/h

Question 39

4d after surgical evacuation of an acute subdural hematoma, a 44yo man becomes mildly lethargic and develops asterixis. he has received 2400mL of 5% dextrose in water IV each day since surgery, and he appears well-hydrated. pertinent lab values are as follows:
serum electrolytes: Na 118, K 3.4, Cl 82, HCOe 24
Serum osmolality: 242 mOsm/L
urine sodium: 47 mEq/L
urine osmolality: 486 mOSm/L
which of the following is the best treatment of his hyponatremia?
a. insulin infusion to keep his glucose level <110
b. slow infusion of 3% normal saline until neurologic sxs are improved
c. rapid infusion of 3% normal saline to correct the sodium to normal
d. desmopressin (DDAVP) administration
e administration of a loop diuretic

Answer 39

B. SIADH –> CNS dz; chest dz; excess ADH present in post-op patients –> intense retention of free water; concentrated urine

very hyponatremic

DO NOT correct rapidly (b/c central pontine myelinolysis)–> slow infusion until Na is normalized

Question 40

43yo woman develops acute renal failure following an emergency resection of a leaking abdominal aortic aneurysm. one week after surgery, the following labs are obtained:
serum electrolytes: Na 127, K 5.9; Cl 92; HCO3 15
BUN: 82
Serum creatinine 6.7.
The pt has gained 4kg since surgery and is mildly dyspneic at rest. 8h after these values are reported, the following electrocardiogram is obtained: widended QRS complexes in II, III, avF, with large QRS complexes in V4-V5. which of the following is the most appropriate initial treatment in the management of this pt?
a. 10mL of 10% calcium gluconate
b. 0.25mg digoxin every 3h for 3 doses
c. oral kayexalate
d. 100mg lidocaine
e. emergent hemodialysis

Answer 40

A

hyperkalemia; hyponatremia
kidney injury

1) discontinue exogenous K
2) calcium gluconate
3) Na bicarb
4) glucose, insulin
5) Kayexalate –> remove K from body - decrease total K

Dialysis

Acidosis
Electrolytes (K)
Intoxication
Overload of fluids = SOB due to pulmonary edema; weight gain
Uremia / altered mental status

Question 41

63y man with a 40 pack per year smoking history undergoes a low anterior resection for rectal cancer and on post-op day 5 develops a fever, new infiltrate on CXR and leukocytes. he is transferred to the ICU for treatment of his pneumonia b/c of clinical deterioation. which of the following is an sign of early sepsis?

a. respiratory acidosis
b. decreased cardiac output
c. hypoglycemia
d. increased arteriovenous O2 diffeerence
e. peripheral vasodilation

Answer 41

E

1) physiological hyperdynamic, hypermetabolic state –> peripheral vasodilation; high catecholamines, cortisol
2) altered MS, tachypnea –> respiratory alkalosis; flushed skin
3) increased CO, decreased SVR, decreased peripheral use of O2

Question 42

60yo woman with no previous medical problems undergoes a total colectomy with diverting ileostomy for a cecal perforation secondary to a sigmoid stricture. postop, she has 2L of ileostomy output per day. her HR is 110 BPM, her RR 24, O2 sat is 98% on 2LNC. Her Hgb levels have been stable post-op at 9. her other lab values on post-op day 6 are as follows:
Na 128
K 3
Cl 102
HCO3 20
which of the following statements is the best strategy for correcting her acid-base disorder?
a. .her maintenance fluids should be changed to 0.9% normal saline with 20 mEq/L of KCl
b. she should be intubated to correct her tachypnea and prevent respiratory acidosis
c. she should be transfused 2U of pRBCs
d. she should be treated with fluid replacemenent and stool-bulking agents
e. she should undergo immediate dialysis

Answer 42

D. she is volume depleted

hyponatremia; hypokalemia

Na - Cl - HCO3 = 128-102-20 = 6

hyperchloremic metabolic acidosis –> likely due to high output from ileostomy; GI losses of bicarb (pancreatic)

NS + KCl –> will increase the non-anion gap acidosis

Question 43

39yo man is undergoing resuscitation with blood products for an upper GI bleed. he is suspected of having a hemolytic transfusion rxn. which of the following is appropriate in the management of this pt?

a. removal of nonessential foreign body irritants, for example, Foley.
b. fluid restriction
c. 0.1M Hcl infusion
d. steroids
e. fluids and mannitol

Answer 43

E

Hemolytic transfusion rxn –> hypotention, oliguria.

1) discontinue transfusion
2) aggressive fluid resuscitation to support BP, increase UO –> will also help clear hemolyzed RBC membranes
3) alkalinization of urine –> prevent Hgb clumping and renal damage

Question 44

45yo woman undergoes an uneventful laparoscopic cholecystectomy for which she receives 1 dose of cephalosporin. 1w later, she returns to the ED with fever, nausea, and copious diarrhea and is suspected of having pseudomembranous colitis. she is afebrile and has no peritoneal signs and abd exam. she has a mild leukocytosis with a L shift. which of the following is the most appropriate initial management strategy?

a. administration of an antidiarrhea agent
b. exploratory laparotomy + L hemo-colectomy and colostomy
c. exploratory laparotomy with subtotal abdominal colectomy and ileostomy
d. administration of IV vanco
e. administration of oral metronidzole

Answer 44

E

oral vanco and oral metronidazole (then IV if recurrent)

Question 45

42yo man sustains a gunshot wound to the abdomen and is in shock. multiple units of pRBCs are transfused in an effort to resuscitate him. he complains of numbness around his mouth and displays carpopedal spasm. an electrocardiogram demonstrates a prolonged QT interval. which of the following is the most appropriate treatment?
a. IV bicarbonate
b. IV potassium
c. IV Ca
d. IV digoxin
E. IV parathyroid hormone

Answer 45

C

high potassium or low Ca –> likely low Ca due to infusion of lots of blood products, where the citrate can decrease

Question 46

A pt has a calculated basal energy expenditure of 2000 kcal/day. Match the following clinical situation with an appropriate daily energy requirement. each lettered option may be used once, more than once, or not at all:
A. 1800 kcal/day
B. 2000 kcal/day
C. 2200 kcal/day
D. 3000 kcal/day
e. 4000 kcal/day
--> Starvation

Answer 46

A

during starvation –> metabolic rate decreases by 10%

avoid refeeding syndrome

Question 47

A pt has a calculated basal energy expenditure of 2000 kcal/day. Match the following clinical situation with an appropriate daily energy requirement. each lettered option may be used once, more than once, or not at all:
A. 1800 kcal/day
B. 2000 kcal/day
C. 2200 kcal/day
D. 3000 kcal/day
e. 4000 kcal/day
--> multiple organ failure

Answer 47

D

Trauma, tress, sepsis, burns and surgery –> increase metabolic rate
Routine operation = 1.1x
Multiple organ failure / severe injury = 1.5x
>50% body surface burns = 2.0x

Question 48

A pt has a calculated basal energy expenditure of 2000 kcal/day. Match the following clinical situation with an appropriate daily energy requirement. each lettered option may be used once, more than once, or not at all:
A. 1800 kcal/day
B. 2000 kcal/day
C. 2200 kcal/day
D. 3000 kcal/day
e. 4000 kcal/day
–> third degree burns involving 60% of body surface area

Answer 48

e

need lots of healing

Trauma, tress, sepsis, burns and surgery –> increase metabolic rate
Routine operation = 1.1x
Multiple organ failure / severe injury = 1.5x
>50% body surface burns = 2.0x

Question 49

A pt has a calculated basal energy expenditure of 2000 kcal/day. Match the following clinical situation with an appropriate daily energy requirement. each lettered option may be used once, more than once, or not at all:
A. 1800 kcal/day
B. 2000 kcal/day
C. 2200 kcal/day
D. 3000 kcal/day
e. 4000 kcal/day
--> after surgery

Answer 49

C

About the same, if not a little higher

Trauma, tress, sepsis, burns and surgery –> increase metabolic rate
Routine operation = 1.1x
Multiple organ failure / severe injury = 1.5x
>50% body surface burns = 2.0x