Foot - Procedural, perioperative management

Question 1

clindamycin is metabolized and excreted by

Answer 1

liver

Question 2

rheumatoid panel

Answer 2

• RF
• anti-CCP
• ESR
• CRP
• ANA
• CBC with diff

Question 3

why discontinue furosemide before surgery?

Answer 3

One of the adverse effects of chronic intake of furosemide, a loop diuretic, is hypokalemia. Loop diuretics inhibit the Na-K-Cl pump, resulting in increased sodium delivery to the distal tubule, resulting in kaliuresis. When it is used with muscle relaxants during anesthesia, it may result in profound muscle relaxation due to hypokalemia and thus complicating the intraoperative period. There is an increased risk of cardiac arrhythmias. Generally, it is advised to omit the morning dose of diuretics on the day of surgery

Question 4

Pletal
treats

Answer 4

“Cilostazol (Pletal) , a phosphodiesterase III inhibitor, is indicated to treat the symptoms of intermittent claudication and increase walking distance in patients with peripheral arterial disease (PAD).

Question 5

what is prolonged in Von Willebrand disease?

Answer 5

hereditary deficiency; which leads to platelet dysfunction.
* normal platelet count,
* prolonged bleeding time, and a
* prolonged partial thromboplastin time (PTT)

Question 6

fat emoboli syndrome
sxs triad

Answer 6

1. petechiae in skin
2. respiratory depression
3. altered state of consciousness

Question 7

fat emboli syndrome:
mechanism

Answer 7

develops 24-72 hours following trauma; can be detected early by continuous pulse oximetry in high-risk patients.
* when fractures of long bones occur, fat droplets are released into the venous system which are then embedded in the pulmonary capillary bed.
* From there, they travel to the brain via AV shunts.
* This results in local ischemia and inflammation, with concomitant release of inflammatory mediators and vasoactive amines and platelet aggregation.

Question 8

compartment syndrome

Answer 8

a pressure higher than 30 mmHg of the diastolic pressure is associated with this; recommend fasciotomy

(or if 20mmHg higher than intra-compartmental pressure)

Question 9

preop

What is the minimal level of hemoglobin prior to elective foot surgery (regardless of gender)?

Answer 9

<10 mg/dl (or <30%)

Question 10

Which of the following factors is the most important in the postoperative recovery period for an ankle fracture?

Answer 10

early mobilization and range of motion

( 1) active exercises accelerate return to work and daily activities compared to immobilization, 2) early weight-bearing tends to accelerate return to work and daily activities compared to late weight-bearing. Active exercises in combination with immediate weight-bearing may be a safe option.)

Question 11

Wells score

Answer 11

calculates risk of developing VTE

Question 12

factors for Wells Score

Answer 12

• Various factors are taken into account like** older ag**e >75 years (particularly ≥85 years),
• poor** ambulation (prior to surgery), **
• obesity, and
• cardiovascular disease.
• Duration of postoperative immobilization and the type of surgery performed also have an effect.
• The risk of developing VTE is greatly increased in polytrauma.

Question 13

which local anesthetic increases risk of cardiotoxicity?

Answer 13

BUPIVICAINE

an amide, is associated with increased risk of cardiotoxicity. At toxic levels, the sodium channel specifity is lost, the agent binds to other cation channels as well. Rapid infusion of bupivacaine 0.5–2 mg/kg has been shown to inhibit baroreflex sensitivity, has negative inotropic effect on the heart, and results in dilatation of blood vessels and inhibition of the firing rate of the sinoatrial node. Typical effects on the electrocardiogram (ECG) include widening of the QRS complex and lengthening of the PR interval.

Question 14

INR for elective surgery

Answer 14

<1.5

Question 15

acute hypovolemic shock

Answer 15

1. start w/ fluid resuscitation of crystalloids
2. if continues to fall, start vasopressors (norepi or dopamine) to maintain blood pressure through vasoconstriction and increase total peripheral resistance

Question 16

lab findings with hypoparathyroidism

Answer 16

decreased blood CALCIUM
increased PHOSPHORUS

Question 17

thrombophlebitis

Answer 17

an inflammatory process that causes a blood clot to develop and block one or more veins. This is most common in the lower extremities. Symptoms often include redness, swelling, and pain.

Question 18

hemophilia

Answer 18

difficult to control nose bleeds
*recurrent atraumatic joint swellings since childhood

(will have increased APTT)

Question 19

what risks are increased with allogeneic blood transfusion

Answer 19

• increased risk of volume overload,
• hypothermia,
• hyperkalemia,
• hypocalcemia,
• acute transfusion reactions,
• hypersensitivity and anaphylaxis, and
• increased risk of infection. Risk of periprosthetic and surgical site infection

Question 20

During the perioperative period: the risk of spontaneous bleeding increases with which platelet count level?

Answer 20

<10,000/microliter

Question 21

what supplement to treat iron deficiency anemia?

Answer 21

vitamin c
(ascorbic acid) aids in iron absorption

Question 22

HLA-B27 arthridities

Answer 22

inflammatory arthritis:
* ankylosing spondylitis,
* reactive arthritis,
* inflammatory bowel disease and
* psoriatic arthritis.

Question 23

what is Ketorolac

Answer 23

an NSAID for pain management

Question 24

half-life of plavix

Answer 24

6 hours

(clopidogrel)

Question 25

antibiotic treatment after contamination with standing water

Answer 25

• preferred: pip/tazo 4.5 g IV q8h
• (if beta-lactamase allergy) levofloxacin 500 mgIV q24h + metronidazole 500 mg IV q8h
• if known mrsa colonication, add vanc 15 mg/kg IV q12hr

Question 26

adrenal crisis/ HPA axis failure is most commonly seen at what dose

Answer 26

high dose glucocorticoids >20 mg per day for more than 3 weeks

Question 27

sxs of malignant hyperthermia

Answer 27

• Tachycardia Cardiac arrhythmia
• Hyperthermia to 104 to 106°F.
• Hypotension and cardiovascular collapse
• may develop Muscular signs (generalized rigidity, masseter spasm, rhabdomyolysis, and hyperkalemia).

Question 28

Which of the following anti-diabetic agents should be avoided during post-operative period if there is a risk of renal insufficiency?

Answer 28

Metformin.

EXPLANATION: Metformin is generally considered a safe drug with minimal side effects. However, it is recommended to avoid metformin postoperatively in patients who have high risk of renal insufficiency due to concerns of lactic acidosis. If contrast medium is to be used in surgery or GFR is less than 60 ml.min−1.1.73 m−2, then it is advised to stop intake the night before surgery and 48 hours post operatively.

Question 29

Which of the following should be most avoided in patients with adrenal insufficiency intraoperatively?

Answer 29

etomidate.

EXPLANATION: Etomidate is a commonly used sedative during rapid sequence intubation. It has been seen that etomidate inhibits 11-beta hydroxylase enzyme that inhibits the production of cortisol and aldosterone. Thus it results in profound hypotension, further aggravating the adrenal insufficiency and adrenal crisis intraoperatively.

Question 30

What is considered a safe minimum CD4 count for a patient undergoing an elective foot and ankle surgery?

Answer 30

200 CD4 cells/mm3.

EXPLANATION: “Specific risk factors influencing operative morbidity include an absolute CD4 count of less than 200 cells/cc3 or viral load greater than 10,000 copies/ml.

Question 32

heparin: periop

Answer 32

• hold 6-12 hours prior to surgery
• restart at 200-400 U/h at 4-6 hours after surgery

Question 33

Which enzyme should be ordered in a patient with a family history of malignant hyperthermia?

Answer 33

Creatine kinase. EXPLANATION: “Malignant hyperthermia is a severe reaction to particular drugs that are often used during surgery and other invasive procedures. Specifically, this reaction occurs in response to some anesthetic gases, which are used to block the sensation of pain, and with a muscle relaxant that is used to temporarily paralyze a person during a surgical procedure. If given these drugs, people at risk for malignant hyperthermia may experience muscle rigidity, breakdown of muscle fibers (rhabdomyolysis), a high fever, increased acid levels in the blood and other tissues (acidosis), and a rapid heart rate. Without prompt treatment, the complications of malignant hyperthermia can be life threatening. People at increased risk for this disorder are said to have malignant hyperthermia susceptibility. Affected individuals may never know they have the condition unless they undergo testing or have a severe reaction to anesthesia during a surgical procedure

Question 34

Rheumatoid factor targets which immunoglobulin?

Answer 34

IgG.

EXPLANATION: “Rheumatoid factors (RFs) are the first autoantibodies described in rheumatoid arthritis (RA), which target the Fc region of IgG.”

Question 35

Abrupt discontinuation of which of the following antihypertensive in perioperative period results in rebound hypertension?

Answer 35

beta blockers

Sudden withdrawal of some antihypertensives like beta blockers and alpha-2 agonists can result in rebound hypertension. It occurs due to upregulation of adrenoreceptors during the blockade period. Abrupt discontinuation will result in increased release of catecholamines, resulting in sudden, uncontrolled, rebound hypertension. It is advised to continue dosage of beta blocker on the morning of surgery.

Rebound hypertension following abrupt cessation of clonidine and metoprolol. Treatment with labetalol. If it is necessary to discontinue, reduce the dose by 50% for first three days. Then reduce another 50% for the next days

Question 36

How long before non-emergent foot and ankle surgery should clear fluid intake be stopped?

Answer 36

2 hours prior to surgery.

EXPLANATION: According to the guidelines of anesthesia, clear fluid intake two hours before surgery does not increase the gastric content, reduced the gastric acid pH and thus does not increase the risk of aspiration. In patients undergoing reconstructive procedures it is recommended to hold clear intake two hours before induction of anesthesia and solid foods should be withdrawn 6 hours before induction.

Question 37

Which of the following antihypertensive medications should be withheld 24 hours prior to elective foot surgery?

Answer 37

ACE inhibitors.

EXPLANATION: Hypertension is one of the most common reasons to postpone elective foot surgery. During induction of anesthesia, systolic blood pressure increases by 40 mmHg along with a surge in pulse rate due to increased sympathetic activation. These effects are more pronounced in patients with untreated hypertension. Antihypertensives are considered safe and are recommended to be taken on the morning of surgery with small sips of water. Beta blockers have a beneficial effect in reducing risk of intra-operative myocardial ischemia. However, there are a few exceptions to this general rule. ACE inhibitors diminish the adequate response of renin angiotensin system, thus resulting in profound hypotension. It is advisable to discontinue ACE inhibitors 24 hours prior to surgery.

Question 38

Following bare-metal stent implantation due to coronary artery disease, what is the recommended length of time to defer elective foot and ankle surgery?

Answer 38

Continue antiplatelet therapy, delay the surgery for 30 days.

EXPLANATION: Dual antiplatelet therapy is recommended in patients undergoing coronary artery angioplasty for at-least 12 months. It reduces the risk of thrombosis recurrence. American heart association recommends to delay the elective non cardiac surgery for at least 30 days after bare metal stent and for at least 6 months after drug eluting stent.

Question 39

for insulin the day of surgery:

Answer 39

Give long acting insulin at ½ the normal dose, and
hold short acting insulin the morning of surgery.

Question 40

nitinol:
composition

Answer 40

45% nickel
55% titanium

Question 41

stress dosing of steroid:
perioperatively

Answer 41

Add 50mg of steroid before incision, then 25 mg of steroid three times daily for 24 hours.

Question 42

if high suspicion of heart failure perioperatively

Answer 42

serum BNP levels
(strong predictor of risk of death and CV events in pts previously diagnosed with heart failure or cardiac dysfunction)

Question 43

half life:
unfractionated subcutaneous heparin

Answer 43

1.5 hours

Question 44

MACE assessment
(major adverse cardiovascular event)

Answer 44

• age >70 years,
• insulin dependent diabetes,
• history of previous coronary artery disease,
• stroke or TIA.
• It also takes into account the type of surgery involved and the functional status of the patient

Question 45

What is the MOST appropriate reperfusion time prior to re-inflatting an ankle tourniquet for a surgery that has passed the 2 hour mark?

Answer 45

If >2 h is required, the tourniquet should be deflated for 5 min for every 30 min of inflation time

Question 47

preop ECG indications

Answer 47

• Age older than 65 years,
• history of heart failure,
• high cholesterol,
• angina,
• MI, or s
• evere valvular disease are associated with clinically significant abnormalities on ECG.

Question 48

how much intraop fluid for patient with HF

Answer 48

Total fluid in such patients should be calculated as follows: 2ml/kg/hr for insensible fluid loss and 3m fluid for each ml of blood lost.

(HF is volume overload condition; if too much fluid, risk for pulmonary edema)

Question 49

calculation for postprandial insulin

Answer 49

It can be calculated by dividing the total daily insulin (TDI) dose by 30 for every 50 mg/dL (3 mmol/L) above the glycemic goal.

eg: a patient with a total daily insulin dose of 150 units with a blood glucose reading of 350 mg/dL. Subtracting the upper end of a normal glucose measurement (200 mg/dL) from the patients reading and dividing by 50 mg/dL yields 3.

Simply multiply this number by the TDI/30 (150/30 = 5) to determine that the patient requires an additional 15 units of rapid acting insulin to restore blood glucose levels back into target range.

Question 50

Which inflammatory marker is most sensitive within the first 48 hours following postoperative implant infection?

Answer 50

C-reactive protein (CRP) level has widely replaced erythrocyte sedimentation rate (ESR) as a marker of inflammation, infection, and tissue damage. There are various important differences between CRP level and ESR, including the enhanced responsiveness and specificity of CRP test results. C-reactive protein levels rise more quickly than ESR (increasing within 2 hours and peaking at 48 hours) and are less affected by anemia, pregnancy, and elevated protein levels.

Question 51

Abnormal lab value that should be considered on all patients taking diuretics?

Answer 51

Hypokalemia.

EXPLANATION: Loop diuretics like furosemide (Lasix) block sodium reabsorption causing excess potassium secretion to occur, causing hypokalemia. The patient is at risk of metabolic alkalosis.

Question 52

How long should antibiotics be stopped before taking a bone culture in the following x-ray?

Answer 52

48 hours.

EXPLANATION: Cultures that are negative can lead to inappropriate choice of antibiotics. A negative culture can lead to unnecessary antibiotic exposure and possible renal disease. BoardWizards Note: The impact of holding antibiotics in diabetic foot infections have never been studied. 48 hours is a number we have seen on several occasions within the podiatric field, but it hasn’t been studied or proven. However, the longer period of time that preoperative antibiotics are held- may aid in a more accurate culture

Question 53

In a diabetic patient scheduled for an achilles tendon lengthening; what is the MOST likely cause of a sudden exacerbation of congestive heart failure and onset of dyspnea and edema?

Answer 53

Actos (pioglitazone).

EXPLANATION: Sudden onset dyspnea and edema in a diabetic patient may be due to medication induced congestive heart failure. Patients taking Thiazolidinediones like Actos (pioglitazone) are at increased risk of developing heart failure. This is commonly due to fluid retention. Fluid retention appears to be mediated through increased sodium reabsorption in the renal collecting tubules. These drugs should be avoided in patients at increased risk of developing heart failure.

Question 54

why does ESR remain elevated even in absence of infection months following injury or surgery?

Answer 54

it can remain elevated for several days until excess fibrinogen is removed from the serum

Question 55

coumadin (warfarin):
periop

Answer 55

• stop 5 days before surgery
• restart 12-24 hours postoperatively

Question 56

Which of the following regimes is most appropriate for acute DVT management?

Answer 56

Apixaban (Eliquis) 10 mg twice a day for 7 days , then 5 mg twice daily.

EXPLANATION: Deep venous thromobsis results in conditions associated with prothrombotic states. It increases the risk of pulmonary embolism, which is associated with increased morbidity and mortality. Different regiemes are available for the management of acute DVT : 1) Apixaban (Eliquis) 10 mg twice a day for 7 days, then 5 mg twice a day; 2) Dabigatran (Pradaxa) 150 mg twice a day after a 5- to 10-day lead-in course of LMWH; 3) Edoxaban 60 mg daily (30 mg if creatinine clearance 30-50 ml/min or potent proton pump inhibitor use) after a 5- to 10-day lead-in course; 4) Rivaroxaban (Xarelto) 15 mg twice a day for 21 days, then 20 mg daily; or 5) Warfarin with a goal international normalized ratio (INR) 2-3 and LMWH for 5-10 days (until INR >2). Underlying etiology should be assessed and treated to avoid recurrent thrombosis.

Question 57

short-term corticosteroid use: risks

Answer 57

generally mild side effects, including:
* cutaneous effects,
* electrolyte abnormalities,
* hypertension,
* hyperglycemia,
* pancreatitis,
* hematologic,
* immunologic, and
* neuropsychologic effects, although occasionally, clinically significant side effects may occur.

Question 58

long-term corticosteroid use: risks

Answer 58

associated with more serious sequela, including:
* osteoporosis,
* aseptic joint necrosis,
* adrenal insufficiency,
* gastrointestinal,
* hepatic and ophthalmologic effects,
* hyperlipidemia,
* growth suppression, and
* possible congenital malformations.” Steroids also cause hyperglycemia, which in turn, can impair wound healing. Finally, steroids do not decrease the chance of an infection

Question 59

clinical standards to prevent post op decubitus ulcers

Answer 59

• consume a high protein, high calorie diet,
• use of air fluidized mattress
• continued support and positioning (every 2 hours) in order to avoid development of pressure ulcers in patients who are immobilized

Question 60

MC sites for postop decubitus ulcer

Answer 60

sacrum, heels, trochanters, and malleoli

Question 61

In patients with rheumatoid arthritis, which of the following should be assessed preoperatively?

Answer 61

Revised cardiac risk index

(rheumatoid arthritis and the medications that are used to treat it have widespread effects on body including the heart, lungs, liver and hematology. Patients with RA are at increased risk of intraoperative myocardial infarction. Therefore, it is necessary to perform a preoperative cardiac risk assessment in patients with RA - using a revised cardiac risk index score)

Question 62

NSAIDs

Answer 62

• containdicated in severe renal disease
• antiplatelet effect
• anti-inflammatory effect
• target both COX-1 and COX-2 inhibitors

Question 63

BLAST for DVT management

Answer 63

• Bleeding risk,
• Life expectancy,
• Anatomy,
• Severity
• Time of symptoms of the DVT before treatment is offered.

For example: Patients with acute thrombus located in the cava or iliac vessels should primarily be considered for these lytic treatments. Patients with popliteal or calf DVT should be anticoagulated. Patients who are pregnant, have active bleeding, or have a very short life expectancy should not be considered for thrombolysis therapy.

Question 64

Which of the following antibiotics is MOST sensitive in treating an infected, Wagner grade 3 diabetic foot ulcer?

Answer 64

Moxifloxacin. EXPLANATION: Diabetic foot ulcer infections are largely polymicrobial in nature. Broad spectrum antibiotics like IV moxifloxacin are commonly used for treating these infections. Other commonly used regimes provide coverage against gram positive, gram negative, and anaerobic bacteria.

Question 65

hypernatremia:
sxs and tx

Answer 65

Hypernatremia leads to pyrexia, nausea, vomiting, convulsions, coma and FOCAL NEUROLOGICAL SIGNS.

Tx: Correction is advisable over 48–72 hrs with 5% dextrose.

Question 66

What is the most appropriate rate that insulin is infused in type 2 diabetics to control intraoperative hyperglycemia?

Answer 66

2-3 U/hr.

EXPLANATION: In patients with type 2 diabetes who are undergoing major surgery, intraoperative hyperglycemia is empirically treated with continuous IV infusion of regular insulin at the rate of 2-3 U/Hr.

Question 67

What is the most appropriate rate that insulin is infused in type 1 diabetics to control intraoperative hyperglycemia?

Answer 67

empirically treated with continuous IV infusion of regular insulin at the rate 0.5-1U/hr.

Question 68

How is hyperglycemia best managed during arthroscopic ankle procedures?

Answer 68

subcutaneous insulin

(because its minor, outpatient surgical procedure)

Question 69

malignant hyperthermia

Answer 69

hypermetabolic response to potent inhalation agents (such as halothane, sevoflurane, desflurane), the depolarizing muscle relaxant succinylcholine, and rarely, in humans, to stresses such as vigorous exercise and heat

Question 70

acute hemolytic transfusion reaction:
symptoms

Answer 70

described as a triad of symptoms; fever, flank pain, and red or brown urine.

Other symptoms are chills, hypotension, renal failure, back pain, or signs of disseminated intravascular coagulation

*STOP TRANSFUSION IMMEDIATELY

Question 71

Amide local anesthetics

Answer 71

metabolized by LIVER

include an “i” in the name lidocaine, mepivacaine, prilocaine, bupivacaine, ropivacaine, and levo-bupivacaine all include an “i” before the “-caine”.

Question 72

ESTER local anesthetics

Answer 72

metabolized by KIDNEYS

procaine, chloroprocaine, and tetracaine do not contain an “i” before the “-caine”.

Question 73

effects of epinephrine added to local anesthesia

Answer 73

• dec bleeding at surgical site
• increased effects of local anesthetics (bc vasoconstrictors reduce absorption of local anesthetic)
• dec minimum quantity of local anesthetic use
• dec peak plasma concentration of local anesthetics

Question 74

pernicious anemia:
lack of

Answer 74

lack of INTRINSIC FACTOR (B12)
causing deficiency in RBCs

Question 75

Which of the following is the best test to rule out suspected adrenal insufficiency preoperatively?

Answer 75

ACTH stimulation test.

EXPLANATION: Intraoperative adrenal crisis has uncontrollable detrimental effects and can cause death. In patients with high suspicion of HPA (hypothalamic–pituitary–adrenal axis) axis suppression or adrenal insufficiency, it is recommended to assess them preoperatively with ACTH stimulation test. 250ug of Cosyntropinis injected and levels of cortisol and ACTH are measured in the blood after 30-60 minutes. Normal levels of cortisol are 18-25 mcg/dl. Any level below 18 mcg/dl is considered diagnostic for adrenal insufficiency.

Question 76

What is the empirical IV insulin dose that is titarated intraoperatively to treat hyperglyemia during a prolonged foot/ankle surgery?

Answer 76

0.02U/kg/hr

Question 77

Which antibiotics are most appropriate for the injury shown?

(Gustillo Anderson IIIB)

Answer 77

CEFAZOLIN AND TOBRAMYCIN

This question is testing two concepts, the first being knowledge of Gustillo Anderson. The injury shown would be classified as a Gustillo Anderson III B injury. The wound obviously does not have adequate soft tissue coverage, and while there is bleeding, the foot is not cyanotic and does not appear to be profusely bleeding. Given only the information gathered from this picture, the most appropriate answer would be IIIB. The second part of the question is testing antibiotic knowledge. The correct answer is D since ONLY D includes a first generation cephalosporin + aminoglycoside. The remaining choices are either 3rd or 4th generation cephalosporins. For Gustillo Anderson III injuries, A,B, and C type injuries all require a first generation cephalosporin + aminoglycoside.