Foot - Procedural, perioperative management Flashcards
1
Q
clindamycin is metabolized and excreted by
A
liver
2
Q
rheumatoid panel
A
- RF
- anti-CCP
- ESR
- CRP
- ANA
- CBC with diff
3
Q
why discontinue furosemide before surgery?
A
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
4
Q
Pletal
treats
A
“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).
5
Q
what is prolonged in Von Willebrand disease?
A
hereditary deficiency; which leads to platelet dysfunction.
* normal platelet count,
* prolonged bleeding time, and a
* prolonged partial thromboplastin time (PTT)
6
Q
fat emoboli syndrome
sxs triad
A
- petechiae in skin
- respiratory depression
- altered state of consciousness
7
Q
fat emboli syndrome:
mechanism
A
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.
8
Q
compartment syndrome
A
a pressure higher than 30 mmHg of the diastolic pressure is associated with this; recommend fasciotomy
(or if 20mmHg higher than intra-compartmental pressure)
9
Q
preop
What is the minimal level of hemoglobin prior to elective foot surgery (regardless of gender)?
A
<10 mg/dl (or <30%)
10
Q
Which of the following factors is the most important in the postoperative recovery period for an ankle fracture?
A
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.)
11
Q
Wells score
A
calculates risk of developing VTE
12
Q
factors for Wells Score
A
- 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.
13
Q
which local anesthetic increases risk of cardiotoxicity?
A
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.
14
Q
INR for elective surgery
A
<1.5
15
Q
acute hypovolemic shock
A
- start w/ fluid resuscitation of crystalloids
- if continues to fall, start vasopressors (norepi or dopamine) to maintain blood pressure through vasoconstriction and increase total peripheral resistance
16
Q
lab findings with hypoparathyroidism
A
decreased blood CALCIUM
increased PHOSPHORUS
17
Q
thrombophlebitis
A
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.
18
Q
hemophilia
A
difficult to control nose bleeds
*recurrent atraumatic joint swellings since childhood
(will have increased APTT)
19
Q
what risks are increased with allogeneic blood transfusion
A
- 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
20
Q
During the perioperative period: the risk of spontaneous bleeding increases with which platelet count level?
A
<10,000/microliter
21
Q
what supplement to treat iron deficiency anemia?
A
vitamin c
(ascorbic acid) aids in iron absorption
22
Q
HLA-B27 arthridities
A
inflammatory arthritis:
* ankylosing spondylitis,
* reactive arthritis,
* inflammatory bowel disease and
* psoriatic arthritis.
23
Q
what is Ketorolac
A
an NSAID for pain management
24
Q
half-life of plavix
A
6 hours
(clopidogrel)
25
antibiotic treatment after contamination with standing water
* 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
26
adrenal crisis/ HPA axis failure is most commonly seen at what dose
high dose glucocorticoids >20 mg per day for more than 3 weeks
27
sxs of malignant hyperthermia
* Tachycardia Cardiac arrhythmia
* Hyperthermia to 104 to 106°F.
* Hypotension and cardiovascular collapse
* may develop Muscular signs (generalized rigidity, masseter spasm, rhabdomyolysis, and hyperkalemia).
28
Which of the following anti-diabetic agents should be avoided during post-operative period if there is a risk of renal insufficiency?
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.
29
Which of the following should be most avoided in patients with adrenal insufficiency intraoperatively?
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.
30
What is considered a safe minimum CD4 count for a patient undergoing an elective foot and ankle surgery?
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.
31
32
heparin: periop
* hold 6-12 hours prior to surgery
* restart at 200-400 U/h at 4-6 hours after surgery
33
Which enzyme should be ordered in a patient with a family history of malignant hyperthermia?
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
34
Rheumatoid factor targets which immunoglobulin?
IgG.
EXPLANATION: “Rheumatoid factors (RFs) are the first autoantibodies described in rheumatoid arthritis (RA), which target the Fc region of IgG.”
35
Abrupt discontinuation of which of the following antihypertensive in perioperative period results in rebound hypertension?
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
36
How long before non-emergent foot and ankle surgery should clear fluid intake be stopped?
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.
37
Which of the following antihypertensive medications should be withheld 24 hours prior to elective foot surgery?
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.
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?
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.
39
for insulin the day of surgery:
Give long acting insulin at ½ the normal dose, and
hold short acting insulin the morning of surgery.
40
nitinol:
composition
45% nickel
55% titanium
41
stress dosing of steroid:
perioperatively
Add 50mg of steroid before incision, then 25 mg of steroid three times daily for 24 hours.
42
if high suspicion of heart failure perioperatively
serum BNP levels
(strong predictor of risk of death and CV events in pts previously diagnosed with heart failure or cardiac dysfunction)
43
half life:
unfractionated subcutaneous heparin
1.5 hours
44
MACE assessment
(major adverse cardiovascular event)
* 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
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?
If >2 h is required, the tourniquet should be deflated for 5 min for every 30 min of inflation time
46
47
preop ECG indications
* 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.
48
how much intraop fluid for patient with HF
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)
49
calculation for postprandial insulin
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.
50
Which inflammatory marker is most sensitive within the first 48 hours following postoperative implant infection?
**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.
51
Abnormal lab value that should be considered on all patients taking diuretics?
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.
52
How long should antibiotics be stopped before taking a bone culture in the following x-ray?
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
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?
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.
54
why does ESR remain elevated even in absence of infection months following injury or surgery?
it can remain elevated for several days until excess fibrinogen is removed from the serum
55
coumadin (warfarin):
periop
* stop 5 days before surgery
* restart 12-24 hours postoperatively
56
Which of the following regimes is most appropriate for acute DVT management?
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.
57
short-term corticosteroid use: risks
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.
58
long-term corticosteroid use: risks
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
59
clinical standards to prevent post op decubitus ulcers
* 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
60
MC sites for postop decubitus ulcer
sacrum, heels, trochanters, and malleoli
61
In patients with rheumatoid arthritis, which of the following should be assessed preoperatively?
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)
62
NSAIDs
* containdicated in severe renal disease
* antiplatelet effect
* anti-inflammatory effect
* target both COX-1 and COX-2 inhibitors
63
BLAST for DVT management
* 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.
64
Which of the following antibiotics is MOST sensitive in treating an infected, Wagner grade 3 diabetic foot ulcer?
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.
65
hypernatremia:
sxs and tx
Hypernatremia leads to pyrexia, nausea, vomiting, convulsions, coma and FOCAL NEUROLOGICAL SIGNS.
Tx: Correction is advisable over 48–72 hrs with 5% dextrose.
66
What is the most appropriate rate that insulin is infused in type 2 diabetics to control intraoperative hyperglycemia?
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.
67
What is the most appropriate rate that insulin is infused in type 1 diabetics to control intraoperative hyperglycemia?
empirically treated with continuous IV infusion of regular insulin at the rate 0.5-1U/hr.
68
How is hyperglycemia best managed during arthroscopic ankle procedures?
subcutaneous insulin
(because its minor, outpatient surgical procedure)
69
malignant hyperthermia
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
70
acute hemolytic transfusion reaction:
symptoms
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
71
Amide local anesthetics
metabolized by LIVER
include an “i” in the name lidocaine, mepivacaine, prilocaine, bupivacaine, ropivacaine, and levo-bupivacaine all include an “i” before the “-caine”.
72
ESTER local anesthetics
metabolized by KIDNEYS
procaine, chloroprocaine, and tetracaine do not contain an “i” before the “-caine”.
73
effects of epinephrine added to local anesthesia
* 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
74
pernicious anemia:
lack of
lack of INTRINSIC FACTOR (B12)
causing deficiency in RBCs
75
Which of the following is the best test to rule out suspected adrenal insufficiency preoperatively?
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.
76
What is the empirical IV insulin dose that is titarated intraoperatively to treat hyperglyemia during a prolonged foot/ankle surgery?
0.02U/kg/hr
77
Which antibiotics are most appropriate for the injury shown?
(Gustillo Anderson IIIB)
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.
78
