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