Anesthesia/Perioperative Management Flashcards
How long should you delay elective non cardiac surgery after
- balloon angioplasty?
- bare metal stent?
- drug eluting stent?
- angio: 2 weeks
- bare metal: 1 month
- drug eluting: 1 year if dual platelet therapy needs to be discontinued or 180 days (if the risk of delay is greater than risk of ischemia)
What is an “acute MI?”
What is a “recent MI?”
How long do you wait to do surgery after an MI?
Acute MI: within last 7 days
Recent MI: happened in the last 8 days to 1 month
After an MI, wait > 60 days
For a 70kg guy, how much local can you give?
- lidocaine with epi
- lidocaine alone
After giving a maximum dose, how long do you wait until giving more?
What about how much volume of 1% lido?
- lido with epi: 70 x 7 = 490 mg
- lido alone: 70 x 4.5 = 300 mg
90 minutes
1% lido: 10mg/mL. 10g/1000mL
For 490mg -> 49mL
For 300mg -> 30mL
For pts who are taking steroids, what do you do with steroid management for moderate surgeries (elective colectomy)?
What about for major surgeries (total procto, open heart surgery, esophagectomy, etc)?
Take the usual morning dose
Give 50mg hydrocortisone IV just before the procedure
Give 25mg hydrocortisone IV every 8 hrs for 24 hrs
Resume usual dose thereafter
* For elective colectomies it is also okay to just continue home dose and not give additional doses.
Take the usual morning dose
Give 100mg hydrocortisone IV just before the procedure
Give 50mg hydrocortisone IV every 8 hrs for 24 hrs
Taper dose by 1/2 per day then resume usual dose thereafter
In 1L of D5 how many kcal are there?
D5 means how many grams of sugar in 1L?
How many kcal per g?
50g in 1L
3.4kcal/g
170 kcal per 1L of D5
What is zoledronic acid?
One of the most potent bisphosphanates.
Can be used to treat really bad hypercalcemia from like bony prostate cancer mets
What EKG changes can hypercalcemia cause?
QT shortening
Bony pain, renal failure, abdominal pain
What can you use to treat hypercalcemia in pts with renal failure?
Can’t use zoledronic acid because it can worsen renal failurecan use DENOSUMAB. mab for RANKL
What do steroids do to calcium?
Reduce intestinal absorption and increase renal excretion
Essentially lowers serum calcium
EKG changes with hypocalcemia?
QT prolongation
Tetany seizure, psychosis
What is the difference between cerebral salt wasting and SIADH in terms of volume status?
both are hyponatremic
Cerebral salt wasting is a hypovolemic state.
SIADH is euvolemic
cerebral salt wasting = hypovolemic, hyponatremia. due to increased BNP
What does demeclocycline do?
Makes the distal tubules less sensitive to ADH
Also acts as an antagonist of ADH
How many days of hyponatremia qualifies as chronic?
How fast can you correct this?
More than 3 days.
1mEq every 2 hours.
12mEq over 24hrs
What is diabetes insipidus?
neprhogenic: Insensitivies of the kidneys to ADH. NOW YOU JUST PEE AND PEE AND PEE. osmotic diuresis
central: brain doesn’t make ADH
What effect does hypophosphatemia have on hemoglobin binding to oxygen?
Low phos -> low 2,3 DPG -> O2 binds more tightly to hemoglobin
What’s the chloride gonna be in pancreatic leak? What acid base?
Non anion gap metabolic acidosis. Because your losing bicarb.
Bicarb is negatively charged. If your using a ton of negative charge, you have to have something negative. Chloride. Hyperchloremic.
What happens in old blood.
2,3 DPG? Oxygen unloading capacity?
Decreased 2,3 DPG. O2 unloading is decreased. Hemoglobin holds on to O2
RNYGB pt with numbness and tingling. What electrolyte derangement? Why?
Calcium. Due to decreased vit D. Because of decreased fat absorption
hypocalcemia causes prolonged QT
hypercalcemia causes shortened QT
Crohn’s disease with nephrolithiasis. Intestinal malabsorption of what can lead to kidney stones?
Fat
Oxalate stone.
Calcium oxalate normally gets excreted through your intestines.
When you have fat malabsorption then fat binds to the calcium instead of the oxalate
Then oxalate has no partner. It gets intestinally absorbed and then excreted in kidneys and form oxalate stones.
Explain the hemoglobin dissociation curve. What does it mean when the curve shifts to the left? Right?
Left shift -> hemoglobin binds tighter to the oxygen.
Right shift -> easier for hemoglobins to let go/unload oxygen
Does increased temperature make it easier or harder for hemoglobins to unload?
Higher temperature -> easier to unload. Downright shift.
Think hemoglobins are more restless so they drop O2
Effect of pH on o2 hgb dissociation curve?
More acidotic -> easier to unload. Downright shift.
Low pH -> downright shift. Easier to unload O2
Effect of pCO2 ON O2-Hgb dissociation curve?
Higher pCO2 -> downright shift. Unloads O2 easier
Effect of carboxyhemoglobin on O2-Hgb dissociation curve?
Treatment of carboxyhemoglobin toxicity?
treatment of carbon monoxide toxicity?
treatment of methemoglobinemia?
treatment for cyanide toxicity?
Left shift. Harder for hgb to let go of O2
carboxy hemoglobin: 100% O2 or hyperbaric
carbon monoxide: 100% oxygen
methemoglobinemia: methylene blue
cyanide toxicity: sodium nitrite
What is winter’s formula?
(Bicarb x 1.5 + 8) +/- 2
It’s when there’s a metabolic acidosis and you’re trying to see if the respiratory compensation is enough
When is it appropriate to give bicarb during CPR?
Cardiac arrest secondary to hyperkalemia
How many hours of metabolic derangement qualifies do one as “chronic” respiratory acidosis for example
how long of having hyponatremia classifies it as chronic?
respieratory acidosis: ~12 hours
hyponatremia: 3 days
For respiratory acidosis how much does kidney/bicarb compensate. Let’s say pCO2 is 65. What should the bicarb be?
For every 10 increase in pCO2 bicarb should go up by 2
Bicarb should go up by (65-40)/10 x2 = 5. Go up by 5
What is the main purpose of early enteral feeds?
Not nutrition. It’s to get just the bare minimum into the gut so the gut still has to work and not atrophy
Atrophy -> leads to breakdown of the barrier and enteric organism into the bloodstream
For child’s pugh, how many points are needed for each class? What is the according surgical mortality?
Child A: 6 or less -> 10% surgical mortality
Child B: 7-9 pts -> 30%
Child C: more than 10 pts -> 75-80%
What is the appropriate DVT prophylaxis for a healthy guy after lap appy? He’s already ambulating
Nothing. Not even SCD. Once they ambulate they don’t need SCD’s.
After a laparoscopic surgery when can a pt get on a flight?
Give at least 96hrs. There is a small chance of venous air embolism.
For laparoscopic procedures, try to keep the insufflation pressure around what?
~15
Why is ketamine contraindicated for somebody with unstable angina?
Ketamine increases myocardial o2 consumption
What drug for benzo overdose and how much?
Flumanezil 0.2mg IV over 30 seconds can be given up to 3mg
Crohn’s pt just had an operation now looks like death.
What is the metabolic derangement? What electrolyes derangement?
Adrenal insufficiency.
No aldo -> can’t absorb sodium. Can’t excrete potassium. Hyponatremia hyperkalemia. Proton can’t be excreted. Acidemia.
Who needs preop EKG?
Asymptomatic pts with diabetes alone vs hypertension: who needs ekg?
Males > 45 with 2 or more atherosclerotic risk factor
Females > 55 with 2 or more atherosclerotic risk factor
Diabetes needs ekg. HTN alone doesnt
Old person needs surgery. Able to groom herself. How many METs?
1-3
Old person needs surgery. Can only climb 1 flight of stairs. How many METs?
4
Old person needs surgery. Can garden. How many METs?
Light garden: 3-4
Heavy garden: 5-6
Old person needs surgery. Able to take a shower herself How many METs?
3-4 METs
In malignant hyperthermia calcium releases and increases intracellular vs extracellular calcium?
Intracellular calcium increases.
Calcium releases from endoplasmic reticulum.
Mechanical bowel prep and ventral hernia repair?
It actually increases wound infection rate. don’t give bowel prep for ventral hernia repair
Statins perioperatively? Why?
Continue.
Decreases all cause mortality
Not only from lipid lowering but also anti-inflammatory, decreases infection, renal failure, respiratory complications
IVC filter early complication rate:
More frequent indication? Therapeutic vs prophylactic?
Most common late complication?
How much of them are removed?
IVC filter early complication rate: ~7% hematoma/pseudoaneurysn
More frequent indication? Therapeutic vs prophylactic? Prophylactic (60%)
Most common late complication? Recurrent DVT
35-40% are removed
Which one reduces post-op ileus? Methylmaltrexone? Gum?
Gum does.
Methylmaltrexone they studied but did not see benefit
Perioperative use of h2 blockers or PPI is associated with what adverse effect?
C.diff
PPI causes hypomagnesemia
62F acute ccy. No angina. Normal ekg. Bare metal stent 1 yr ago, on plavix. What to do with surgery and plavix?
Go ahead and do surgery. Continue plavix
Lap CCY: low risk for post-op bleed
64F, 2cm DCIS left breast. Had 4 bare metal stents 2 years ago. Asymptomatic. On ASA, plavix. What to do with anti-platelets?
Dc plavix 5d before surgery, continue aspirin
Lumpectomy: low risk.
72F cecal cancer. Takes plavix for previous stroke. What to do with plavix for lap R hemi?
Can continue plavix
65M elective sigmoid for diverticular dzs. Drug eluting stent 1 yr ago. On ASA, plavix. What to do with anti-platelets?
Stop plavix 1 wk prior
Continue aspirin
Sigmoid is major surgery.
For bariatric surgery, preop prophylactic ivc filter placement is associated with what outcome?
Increased risk of VTE
Post-op pt complicated sigmoid. Epidural. Now has LLE weakness in femoral nerve distribution. Next step? Most likely diagnosis?
MRI TL spine r/o epidural hematoma
65M sigmoid cancer. Had drug eluting stent 6mo. Ago. On asa325, plavix. What to do?
D/c plavix. Continue ASA
Delaying is not appropriate
Caprini score meaning?
Pt with caprini score 7 gets a Whipple. Recommended DVT ppx?
Score to assess DVT risk for surgical pts
0-2: low risk
3-4: moderate
>5: high risk
DVT ppx: lmwh for 4 weeks because 7 is high risk
Does using ultrasound during IJ reduce:
- number of passes to cannulate
- pneumothorax
- arterial cannulation
- time to cannulate
- number of passes to cannulate: yes
- pneumothorax: no
- arterial cannulation: yes
- time to cannulate: yes
reduces everything except pneumothorax
Which one reduces SSI more?
Smoking cessation 4-6 weeks before surgery
Vs
Optimization of hemoglobin A1c?
Smoking cessation»_space;> A1c
T/F: etomidate is safe to use in malignant hyperthermia
True.
Between morphine, fentanyl and Dilaudid, which one is most likely to cause histamine release?
Morphine > Dilaudid > fentanyl
What is meperidine? What is its known side effect?
Demerol. Seizure
it’s metabolized into normeperidine. it’s a neurotoxin
Unstable angina. What ASA?
Asa4
Which of the following causes paralytic ileus?
- beta blockers
- alpha agonist
- histamine
- NSAIDs
- acetaminophen
Alpha agonist causes paralytic ileus
Also, anti-histamine, anti-chilinetgics
What is the SSI rate for
Clean procedure
Contaminated
Dirty
Clean procedure: 1-2%
Contaminated: 5-10%
Dirty: 30%
What is the initial management of beta blocker overdose?
IV fluid, 1mg atropine up to 3mg then glucagon
Treatment for cyanide toxicity
Sodium nitrite and sodium thiosulfate
Most common indication for kidney transplant?
Highest risk factor for AAA?
Highest risk factor for stroke?
Most common cause of ischemic stroke?
Most common risk factor for renal cell carcinoma?
Txp: diabetes > HTN
AAA: smoking
Stroke: hypertension
Ischemic stroke: cardioembolic disease
RCC: smoking
When you give a drug 5 half lives of continuous dosing, what percentage of the steady state concentration of this drug is present?
A) 12% B) 25% C) 50% D) 75% E) 97%
97%
what to give to somebody who is in myasthenia crisis despite neostigmine and naloxone?
plasmapheresis
