Drugs Flashcards
What are the disadvantages of using etomidate on induction?
Inhibitor of endogenous steroid synthesis thru inhibition of 11-beta hydroxylase
Does not block sympathetic response to tracheal intubation (need beta blocker or opioid too)
PONV
Myoclonus
What antibiotics cover for pseudomonas ?
Piperacillin/tazobactam Cefepime Imipenem/meropenem Cipro Moxi Levofloxacin
What antibiotics due gram negative coverage?
Gentamicin
Tobramycin
Amikacin
What antibiotics for gram positive coverage?
Cefazolin for skin flora
Linezolid or vanc for MRSA
What about anaerobic coverage?
Metronidazole
Clindamycin
What is AMICAR?
Anti fibrinolytic
Decreases plasminogen to plasmin so that it cannot break up fibrin clot
What are the American Red Cross transfusion guidelines for platelets?
They do not have to ABO or Rh compatible.
They should be when possible.
You should consider anti-Rh globulin when you have given Rh+ platelets to a female patient who is Rh - to avoid erythroblastosis fetal is in the future
What are the transfusion guidelines for FFP ?
Must be ABO compatible
Do not have to cross matched or Rh compatible
What is the transfusion threshold for patients that are hemodynamically stable ?
7 g/DL
What is the transfusion threshold for patient undergoing orthopedic, cardiac surgery or pre-existing cardiac disease?
8 g/DL
What are the transfusion guidelines for someone with sickle cell preoperatively?
Transfuse to Hgb of 10 g/DL (use leukocyte reduction!)
If at 8.5 g/DL and on hydroxyurea, undergoing high risk surgery - consult heme
For an untreated SCD patient, what are the preop guidelines?
Avoid transfusion to greater than 10 g/DL due to risk of hyper viscosity
When do you give platelets preoperatively?
When platelet count is less than 50K if bleeding may be an issue.
Do NOT have to do this for minor surgeries or vaginal deliveries
What are the transfusion thresholds for a patient with multiple trauma or CNS injury?
< 100K
What is FFP deficient in?
Factor V and VIII
What does cryoprecipitate contain?
Concentrated levels of fibrinogen (150 mg in 5-20 ml of plasma) Factor VIII (80 IU) VWF Factor XIII Fibronectin
What are the transfusion guidelines for cryoprecipitate?
Do not need to be ABO compatible
Do not need to be Rh compatible
CMV testing and leukocyte reduction are not required
What is the advantage of using propofol over a barbiturate in a patient with liver disease?
Propofol has a high extraction ratio, does not depend on hepatocytes,
Barbiturates are highly bound to albumin, in liver disease you will have low albumin causing increased FF of barbiturates so longer duration or action. Additionally barbs rely on P450 system for metabolism which is impaired in liver disease
Why are the differences of LMWH compared to unfractionated heparin?
Stronger inhibitors of factor Xa Lower risk of osteopenia Smaller molecular structure Less release of vwf (better for patients with NSTEMI or unstable angina) Lower incidence of HIT Longer half life so less frequent dosing
What are the indications for erythropoietin administration?
Reduce need for RBC transfusions for patients with Hgb > 10 g/DL but less than 13 who are high risk for periop blood loss
Need to give daily for 10 days before surgery, DOS, and 4 days after
Or 4 doses administered 21, 14, and 7 days before surgery and DOS.
What is platelet transfusion threshold for major elective surgery?
Less than 50K
What is the therapeutic range for patients with mechanical valves of warfarin?
2.5-3.5
What herbal medicine inhibit platelet aggregation
Bilberry Bromelain Dong Quoi Feverfew Fish oil Flaxseed oil Garlic Ginger Ginkgo Grape seed extract Saw palmetto
What herbals inhibit clotting?
Chamomile
Dandelion
Dong Quoi
Horse chestnut
What do you do if you suspect ABO incompatibility?
Stop the transfusion
Support!
Aggressive transfusions of platelets, FFP and cryogenic to counteract consumptive coagulopathy
What is the cause of TRALI?
Donor anti-HLA antibodies to plasma components of blood (FFP or platelet) causing complement activation
What do you suspect with hypotension and hyperthermia after giving platelets?
Sepsis from bacterial contamination
Stop transfusion! Start antibiotics and supportive measures
Why is Isoflurane best for liver cases?
Preserves splanchnic blood flow
Vasodilates hepatic vessels
What is in the preservation fluid for a liver transplant?
Potassium
Lactobionate and raffinose - prevent cell swelling
Hydroxyethyl starch - increase oncotic pressure
Allopurinol and glutathione - reduce oxygen free radicals
Adenosine - promote ATP production
At what dose and duration of prednisone are patients considered HPA suppressed?
20 mg/day for over 3 weeks
What are the periop guidelines of steroid administration for someone who is suppressed and undergoing major surgery?
Give daily dose plus 100 mg IV hydrocortisone before incision
Then give infusion of 200 mg of hydrocortisone over 24 hour in D51/2NS
Then taper
What are the periop guidelines of steroid administration in patient undergoing minor surgery who are suppressed?
Give 50 mg IV before incision
Then 25 mg IV q8h X 24 hours
Then taper over 1-2 days to daily dose
What are the periop guidelines of steroid administration in patient undergoing moderate surgery who are suppressed?
Give 50 mg IV before incision
Then 25 mg IV q8h X 24 hours
Then taper over 1-2 days to daily dose
What are the alternative anticoagulants in HIT?
Argatroban
Bivalirudin
Lepirudin
MOA: direct thrombin inhibitors
What is the loading dose of bivalirudin and maintenance dose?
1 mg/ kg loading dose
2.5 mg/kg/ hr infusion
Half-life of 25 minutes
Renally cleared
Can still use ACT
No reversal agent - can use PCC, FFP
What is the difference in lepirudin and bivalirudin?
Lepirudin has a longer half life of 80 minutes and
Bivalirudin is safer, more evidence behind it
What is HIT?
IgG mediated antibody reaction to Plt factor 4 and heparin complexes resulting in arterial thrombosis and TCP
Happens within 4-14 days of heparin administration
What it type 1 HIT?
Drop in platelets without thrombosis
Not immune mediated
What are the problems if someone takes ephedra?
Increased circulating levels of norepinephrine, decreased stores –> may have hypotension refractory to vasopressors due to receptor down regulation
What are the problems if someone takes St John’s wort?
Delayed emergence due to hypericin (GABAergic)
What drugs do you want to avoid if a patient is on MAOi?
Ephedrine
Meperidine
Methylene blue
What is the difference between NMS and serotonin syndrome?
Serotonin syndrome symptoms are clonus and hyperreflexia
NMS has rigidity but hyperreflexia
When should removal of a neuraxial catheter happen after discontinuation of IV heparin?
2-4 hours
How long should you wait to start IV heparin after epidural placement?
Subq heparin?
1 hour
Can do immediately for subq because peak drug effect is 2 hours
What is low dose LMWH and how long do you need to wait to place neuraxial?
Lovenox 30-40 mg subq BID or q day
Dalteparin 5,000 u q day
Wait 12 hours for removal or placement
Restart 2 hours after removal
How long do you need to hold ticlodipine for neuraxial?
14 days
How long do you need to delay neuraxial for clopidogrel or prasugrel?
7-10 days
How long do you delay restarting Plavix or prasugrel after neuraxial?
At least 6 hours
How long do you delay for ticagrelor to do neuraxial?
To restart?
5-7 days
6 hours
How long do you wait if they’re on abciximab? What is abciximab?
24-48 hours
It’s a G2b/3a inhibitor
When is it safe to do neuraxial after eptifibitide or tirofiban? What are these?
4-8 hours
g2b/3a inhibitors
What are ticlodipine, prasugrel, clopidogrel, ticagrelor?
P2Y12 receptor inhibitors
Thienopyridine derivatives
What is the safe time to wait for neuraxial placement or removal if the patient is on antifibrinolytics?
No one knows
Can monitor fibrinogen to guide management
How long do you wait for neuraxial placement or removal with direct thrombin inhibitors (pradaxa, lepirudin, argatroban, bivalirudin)?
5 days
Wait 6 hours to redose after catheter removal
What is the safest time for neuraxial with fondapari nix and apixaban or rivaroxaban? What are these drugs?
72 hours
Resume after 2 hours
Factor Xa inhibitors
What drugs should you avoid in renal failure?
Pancuronium Glycopyrrolate Atropine Ketamine Meperidine Morphine Diazepam
What does cyclosporine do to NMB?
Potentiation of effect of atracurium and vecuronium
What does azathioprine do to muscular blockade?
Competitive antagonism
What can bromocriptine cause?
Gastroparesis
What is the mechanism of action of bromocriptine?
D2 agonist
Inhibits release of prolactin and GH
What is the mechanism of action of octreotide?
Somatostatin analogue
Inhibits release of lots of hormones including GH
Can shrink pituitary adenoma size
What are the signs of lithium toxicity?
Polyuria AV block, widened WRS Seizure Hypotension Skeletal muscle weakness Ataxia Sedation
What we the anesthetic considerations for someone taking lithium?
Prolongation of neuromuscular blockade
Reduces MAC requirement
Drugs that increase lithium levels: thiazides, ACEi, NSAIDs
Can cause vasopressin resistant diabetes insipidus
Use sodium solution to prevent renal reabsorption of lithium (exchanged in proximal tubule for Na)
Which drugs can raise lithium levels?
ACEi
NSAIDs
Thiazides
What does PTU do?
Stops synthesis of thyroid hormone
Decrease the conversion of T4 to T3
Takes 6-8 weeks to work!
What does iopanic acid do?
Inhibits thyroid hormone release
Inhibits conversion of T4 to T3 (can reduce T3 levels within 6-12 hours by 50-75%)
Should be given within 1 hour of PTU in thyroid storm
Don’t give preop unless euthyroid already
What is the treatment for hypocalcemia from thyroidectomy?
10 ml of 10 % calcium gluconate over 10 minutes
Treat hyperkalemia and hypomagnesemia
Get EKG to monitor for symptoms
Why would you not use aspirin to treat fever due to thyrotoxicosis
Because it displaces thyroid hormone from binding proteins in the blood
What are the catecholamine depleting agents you can use in thyroid storm?
Reserpine
Guanethidine
What are the contraindications ft cell saver?
Hemoglobin apathy
Amniotic fluid
Contamination with meds, methyl methacrylate, bone chips, urine,
Pheochromocytoma
Cancer (can do is process, wash and use a leukodepletiom filter)
Sepsis
What are the complications of cell saver?
Hemolysis
Systemic contamination
Nephrotoxicity (high levels of free hemoglobin)
Coagulopathy
Pulmonary injury 2/2 leukocyte activation
Gas embolism
Fever
What drugs are safe to give with porphyria?
Ketamine Propofol NMBs Opioids Volatile
What anesthetic drugs are known to induce the P450 system?
Thiopental
Ketorolac (Toradol)
Etomidate
Methohexital
What is hematite used for?
Increasing the pool of heme and thereby decreasing the activity of ALA synthetase in porphyria crisis
What drugs should be given based on IBW on induction and maintenance?
Vecuronium
Rocuronium
Remifentanil
Why is diltiazem used over verapamil?
Because it produces significantly less myocardial depression
How does epinephrine treat anaphylaxis?
Alpha vasoconstriction
Beta bronchodilation
Increases intracelluar cAMP thereby restoring membrane permeability and decrease of vasoactive mediators
What is the dose of epi for anaphylaxis without complete cardiac collapse?
10 Mcg IV
What is the dose of epi in anaphylaxis with cardiac collapse?
100 Mcg - 1 mg
What is antithrombin III?
Serine protease that binds thrombin, factor X, XI, XII and XIII and enhances Anticoagulation
Heparin binds this and increases its activity 1000X
At what dose is developing cyanide toxicity is low with nitroprusside?
Less than 0.5 mg/kg/hr
What are the risks of giving Rh + blood to a male patient if Rh type is unknown?
Delayed transfusion reaction
Alloimmunization - would type after surgery and administered Rhogam within 72 hours if Rh negative
Do platelets have to ABO compatible?
If they are apheresis platelets, then YES because they are suspended in plasma containing anti- and B antibodies
Can you give a FFP with AB blood type to a patient with unknown blood type?
Yes, because this plasma does not have antibodies to A or B
Would you proceed with a surgery after traumatic needle placement of an epidural?
Yes, if they were not going to be fully heparinization
If fully heparinization - must wait for 24 hours
What should you do if the INR is less than 4.5 and there needs to be urgent reversal?
Consider vitamin K 2.5 mg po
What should you do if there is life-threatening bleeding and INR is < 4.5?
Hold warfarin
Vitamin K 10 mg IV over 30 minutes
4 units of FFP or Kcentra
What should you do if INR is between 4.5-10 and needs urgent reversal?
Vit K 2.5 mg po
1 mg IV
What should you do if INR is over 10 and you need urgent reversal?
Vit K 1-2 mg IV over 30 minutes
Repeat every 6-24 hours as needed
