Exam 3 Material Flashcards
List the 4 steps of hemostasis
- Vascular spasm
- Formation of platelet plug (primary hemostasis)
- Coagulation and fibrin formation (secondary hemostasis)
- Fibrinolysis
Platelets contain the following components
Actin
Adenosine diphosphate
Calcium
Where and how are platelets produced
By megakaryocytes in the bone marrow
Normal platelet levels
150,000-300,000mm3
How long do platelets live
8-12 days (1-2weeks)
apex
How are platelets cleared
Macrophages in the reticuloendothelial system and the spleen
What’s the function of actin
Helps the platelet contract to form a platelet plug
What is the function of glycoproteins
Adheres to injured endothelium, collagen and fibrinogen
What is the function of ADP
Platelet activation and aggregation
What is the function of serotonin in the platelet
Activates nearby platelets
What is the function of growth factor in the platelet
Helps repair damaged vessel walls
Which substance is responsible for adhering the platelet to the damaged vessel
Von Willebrand Factor
What substance is responsible for platelet activation and aggregation
ADP
Thromboxane A2
apex
list the 3 steps required to produce a platelet plug
adhesion
activation
aggregation
Von Willebrand factor binds to the platelet during which step
adhesion (step 1)
How does the injured blood vessel initially activate the platelet plug
endothelial injury exposes collagen which activates platelets
what are the vitamin K dependent factors
2
7
9
10
What is the first coagulation factor activated in the extrinsic pathway?
Tissue Factor (3)
what factors are part of the extrinsic pathway
3 and 7
how fast can a clot form via the extrinsic pathway
~ 15 seconds
what is the first factor to be depleted in the patient with vit K deficiency
factor 7
a deficiency of what factor causes hemophilia A
factor 8
how long does it take to form a clot via the intrinsic pathway
up to 6 min
what factors make up the intrinsic pathway
12
11
9
8
what is the role of thrombin
it converts fibrinogen to fibrinogen monomer
what must be present to convert fibrinogen monomer to fibrin fibers
calcium (factor 4)
2 true statements regarding fibrinolysis
- D dimer measures fibrin split products
-alpha 2 antiplasmin inhibits the action of plasmin on fibrin
what are 4 mechanisms that counterbalance clot formation
- vasodilation and washout of ADP and TxA2
- Antithrombin inactivating thrombin
- tissue factor pathway inhibitor neutralizes tissue factor
4 release of protein C and S
what are 2 enzymes that convert plasminogen to plasmin
1 tPa
2 Urokinase
what 2 enzyme inhibitors turn off the fibrinolytic process
- tPa inhibitor (TPAI)
- alpha 2 antiplasmin
how are plasmin activators used therapeutically
they help dissolve thrombi to restore blood flow
Identify the best predictor of bleeding during surgery
History and physical
What is a normal platelet count
150,000-300,000mm3
A platelet count less than 20,000mm3 increases the risk of?
Spontaneous bleeding
What lab test measures for fibrinolysis
D dimer
Heparin inhibits which pathway(s)
Intrinsic and common pathway
Where is endogenous heparin produced
Liver
Basophils
Mast cells
On what part of the coagulation cascade does heparin work
Intrinsic and common pathways
Where should the aPTT be maintained for active VTE
1.5-2.5 times normal
What is a normal ACT
90 seconds
Apex
What are 3 contraindications to heparin administration
- Neurosurgical procedures
- HIT
- Regional anesthesia
Warfarin inhibits factors
2, 7, 9, 10
Proteins C and S
Where do we obtain inactive vitamin K?
Diet
Manufactured in the gut via bacteria
How does warfarin work
Inhibits vitamin K epoxide reductase complex 1 (an enzyme)
This directly inhibits production of vitamin K dependent factors 2,7,9,10 and proteins C and S
What are the antidotes for warfarin
Vitamin k
FFP
What is the therapeutic level for PT/INR for patient on warfarin
2-3 times normal
What is the dose for exogenous vitamin K
10-20mg PO, IM or IV
Apex
What risk is associated with IV phytonadione
Life threatening anaphylaxis
IV admin is best avoided, if have to give IV rate should not exceed 1mg/min
Apex
What is MOA for clopidogrel
ADP receptor antagonist
What is MOA of Abciximab
GpIIb/GpIIIa receptor antagonist
Warfarin MOA
Vitamin K antagonist
Enoxaparin MOA
Antithrombin cofactor
A patient scheduled for coronary revascularization is diagnosed with type 3 von willebrand disease. What is the best treatment for this patient?
vWF/ factor 8 concentrate
Which type of vWF disease responds best to desmopressin?
Type 1
What is the first line agent for patient with type 3 vWF disease?
Purified 8-vWF concentrate
What coagulation factors are in cryoprecipitate
8
13
Factor 1 (fibrinogen)
vWF
Cryo is useful in treating which type of vWB disease
Type 1,2,3
What coagulopathies present with prolonged PTT and normal PT
Hemophilia A and B
Hemophilia A and B affect what factors?
8 hemophilia A
9 hemophilia B
Which type of hemophilia is more severe
Hemophilia A
Which pathway in coag cascade is affected by hemophilia A and B?
Intrinsic pathway
PTT will be prolonged with severe disease, slightly prolonged with mild disease
What should always be performed before surgery with a severe hemophilia?
Type and cross
6 treatments for hemophilia A
Factor 8
FFP
Cryo
DDVAP
Antifibrinolytics
Recombinant factor 7
Recombinant factor 7 increases risk of
Arterial thrombosis (MI and stroke)
Venous thrombosis (DVT and PE)
Define DIC
Disordered clotting and fibrinolysis that leads to hemorrhaging and systemic thrombosis
Conditions with high risk of DIC
Sepsis
Ob
Cancer (adenocarcinoma, leukemia, lymphoma)
Signs of DIC
Ecchymisis
Petechiae
Mucosal bleeding
Bleeding at Iv site
Prolonged PT/PTT
Increased D dimer and fibrin split products
Decreased fibrinogen and antithrombin
Side effects of cisplatin
Acoustic nerve injury
Nephrotoxicity
Side effect of vincristine
Peripheral neuropathy
Side effect of bleomycin
Pulmonary fibrosis
Side effect of doxorubicin
Cardiotoxic
Side effects of methotrexate
Bone marrow suppression
What meds can increase risk of hyperkalemia when used with K sparing diuretics?
ACE
ARBs
NSAIDs
Beta blockers
Apex says beta blockers, his ppt said the others
Which potassium sparing diuretic antagonizes aldosterone at the mineral cortical is receptors
Spironolactone
Side effects of potassium sparing diuretics
Hyperkalemia
Metabolic acidosis
Gynecomastia
Libido changes
Nephrolithiasis
How can loop diuretics affect nondepolarizing neuromuscular blockade
Potentiates it
What cross sensitivity can happen with furosemide
Cross sensitivity with allergies to sulfunamides
Thiazide diuretics can ___ nondepolarizing neuromuscular blockade
Potentiate
NSAIDs and thiazide diuretics
NSAIDs decrease effectiveness of thiazide diuretics
Which hormones are released by the anterior pituitary gland
Prolactin
Luteinizing hormone
Melanin
Growth hormone
ACTH
Tsh
Anesthetic considerations for the patient with diabetes insipidus
DDAVP to treat
When compared to T4 which statements best describe T3
T 3 has:
Shorter half life
Higher potency
Less protein bound
Smaller conc in the blood
What are 2 CV side effects of hypocalcemia
-hypotension
-prolonged QT interval
What are the 4 Bs when treating the patient with thyroid storm?
- Block synthesis (methimazole, carbimazole, PTU, potassium iodine)
- Block release (radioactive iodine, potassium iodine)
- Block T3 to T4 conversion (PTU, propranolol, glucocorticoids)
- Beta-blocker (propranolol, Esmolol)
List 4 ways the body responds to hypocalcemia
-parathyroid gland releases PTH
-osteoclasts in bone release Ca2+
-Ca is reabsorbed in the kidneys
-Ca absorption in the gut increases in the presence of vitamin D
How does aldosterone affect renal function
-increases Na and water reabsorption
-increases K and H excretion
How much cortisol does the body produce each day
Average cortisol production is 15-30mg/day, dr p s says 10 to 20
with a normal serum level of 12 mcg/dL
How does cortisol production change in response to perioperative stress
Major perioperative stress can increase cortisol production upwards of 100mg/day, with serum level up to 30-50mcg/dL
what are the hemodynamic effects of cortisol
cortisol improves myocardial performance by increasing the number and sensitivity of beta receptors on the myocardium
cortisol is also required for the vasoconstrictive effects of catecholamines
what are the 3 most relevant endogenous steroids
cortisol
cortisone
aldosterone
what steroid has the greatest mineralocorticoid effect
aldosterone
its 3000 times more potent than cortisol
which synthetic steroid is best suited to treat addisons disease
Prednisone
of all the synthetic steroids, it most closely resembles cortisol
what herbal supplement can cause a syndrome that resembles hyperaldosteronism
Licorice
4 signs of Cushing’s syndrome
HTN
HYPOkalemia
metabolic alkalosis
hyperglycemia
a patient with adrenal insufficiency and sepsis requires an emergency intubation in the intensive care unit. which drug should be avoided
etomidate
by inhibiting 11BH a single induction dose of etomidate can cause adrenocortical suppression for >8hrs
this could cause acute adrenal crisis.
what is protamine typically used for
reversing heparin
what is the MOA for the antifibrinolytic agents TXA and EACA
Competitively inhibit activation of plasminogen to plasmin
low factor 13 puts patient at risk for?
bleeding
what is the preferred treatment for vitamin K antagonist reversal in emergent situations
PCC or FFP
fibrinogen levels can increase lab measures of hemostasis including prothrombin time and partial thromboplastin time which may not be corrected with transfusing FFP. What product is better suited for transfusion in this situation
Cryoprecipitate
what is a potential risk for giving TPA for an ischemic stroke
conversion from ischemic stroke to hemorrhagic stroke
true or false: protamine works to neutralize LMWH
False
what two sites do most anticoagulants work on
10a and 2a
which medication primarily targets the chemoreceptor trigger zone
ondansetron
when should ondansetron be given in surgical patients
30 min before emergence
true or false: H2 receptor antagonists have an influence on pH of gastric fluid that is already present in stomach
False
when should oral omeprazole be given before anticipated induction of anesthesia for chemoprophylaxis (PONV)
> 3 hrs before
what is the site of action for loop diuretics
thick ascending loop of henle
true or false: Metoclopramide and other prophylactic drugs (antacids/ H2 antagonists) can replace the need for an artificial airway due to its strong effects in GI motility and pH neutralization
False
rapid administration of metoclopramide can induce what
abdominal cramping
what is the MOA for carbonic anhydrase inhibitors
noncompetitive inhibitors of enzyme activity in the PROXIMAL CONVOLUTED TUBULE
what diuretic should you avoid in a patient with gout
thiazide diuretics
which pump do the aldosterone antagonists work on
sodium/potassium pump in collecting duct
what side effect would require d/c in statin medications
muscle weakness side effects
true or false: statin medications decrease LDL levels through alterations in cholesterol synthesis and uptake of LDL in the liver
true
which statin would increase the risk of muscle myopathy and rhabdo with use if fibrates
lovastatin
what is the half life and onset for regular insulin
half life: 5-10min
onset 30-60 min
what are side effects of systemic corticosteroids
HTN
HYPERglycemia
adrenal suppression
increased risk of infections
peptic ulcers
when would a systemic corticosteroid be given
copd/asthma exacerbation
what nerve is at risk of damage during parathyroid or thyroid surgery
recurrent laryngeal nerve (vocal cord closure)
what type of anesthesia technique is preferred during parathyroid/thyroid surgery
TIVA
allows nerves to still respond to make sure recurrent laryngeal nerve is working during surgery
what type of anesthesia would be avoided if trying to monitor nerve function
paralytic
what is the onset, peak and duration of regular insulin
onset: 30-60 min
peak: 2-4 hrs
duration: 5-8 hrs
what type of insulin is used preop and post op
regular insulin
easier to have tighter control without long term effects
what are risk factors for thyroid storm
surgery
pregnancy
trauma
acute illness
what are symptoms of thyroid storm
T3 and T4 elevated, TSH low
fever, tachycardia, confusion, sweating
how can thyroid storm affect anesthesia
increases metabolism of drugs- need to increase drug administration
how can you treat thyroid storm
propylthiouracil
beta blockers- propanolol/esmolol
plasmapheresis/dialysis to remove thyroid hormone
what can severe hypothyroidism lead to and what are the symptos
myxedema coma
hypothermia, loss of conciousness
give thyroxine
what is the most common acute complication of pituitary disorders
diabetes insipidus
give DDAVP
what is a disease for acute adrenal insufficiency
addisonian crisis
what are three recommended induction agents during thyroid surgeries/hyperthyroidism
fentanyl
propofol
dexmeditomodine
true or false: general anesthesia is recommended for thyroid surgeries
false
TIVA
what meds can be given for HPA suppression
hydrocortisone, dexamethasone
what drug class is good at preventing opioid induced nausea/vomitting
antipyschotics- perphenazine
what are the four extrapyramidal symptom groups
acute dystonic
drug induced akathisia
drug induced parkisonism
tardive dyskinesia
what electrolyte imbalances can diuretics cause that potentiate NMB drugs
HYPOkalemia
HYPOcalcemia
what can diuretics cause during operation with blood pressure
hypovolemia=hypotension
true or false; daily diuretics should not be taken the day of surgery?
TRUE
where does osmotic diuretics work
proximal convoluted tubule
where does loop diuretics work
thick ascending loop of henle
where do thiazide diuretics work
early distal tubule/distal convoluted tubule
where do sodium channel blocker diuretics work
collecting tubule
where do aldosterone antagonist diuretics work
collecting tubule
what can omega 3 fatty acid (fish oil) cause
increased risk of bleeding
what can vitamin B3 (niacin) in nondiabetic patients cause
HYPERglycemia
how long should fish oil be d/c’d for surgery
at least a week
true or false: pt can continue statins all the way up to surgery
true
what can happen if you touch scopolamine patch and dont wash your hands then touch eyes
dry eyes and dilate them
what anesthetics increase PONV
NO
opioids
volatiles
neostigmine
what surgical factors increase risk of PONV
length/type of surgery
what patients are more at risk for PONV
women
non-smoker
hx motion sickness
past episode of PONV
when should you not give metoclopramide
small bowel obstruction
major bowel surgery
intrabdominal surgery where high motility will cause problem
what patients may benefit from metoclopramide before a surgery
DM
obese
pregnant
trauma
any pt recently ingested food
what does activation of the HPA axis in response to surgical stimulus cause
increased secretion of catabolic hormones
what is the pathway for HPA axis to release more cortisol
1- hypothalamus- corticotrophin releasing hormone stimulates
2-anterior pituitary to release adrenocorticotropin releasing hormone (ACTH) which stimulates
3- adrenal cortex to release cortisol
cortisol has what effects?
mineralocorticoid and glucocorticoid effects
how does cortisol promote HYPERglycemia
promotes gluconeogenesis in liver
protein catabolism
reduces peripheral glucose utilization
what are four meds that can affect release of adrenocortical hormones
opioids
midazolam
dexmedetomidine
etomidate
what are two ways to suppress release of cortisol to prevent surgical stimulus
high dose opioids
extensive dermatological blockade during regional anesthesia
what disease causes excessive release of growth hormone from pituitary gland
acromegaly
what are anesthetic considerations during acromegaly surgery
difficult airway
blood sugar monitoring
hydrocortisone replacement post op
what is the drug of choice for preop optimization for thyroidectomy
carbimazole
optimize hormone levels
what are anesthetic considerations for thyroidectomy
carbimazole preop
difficult airway equipment
atropine/glyco to dry secretions
opioid/dex/propofol
monitor NMB for myasthenia gravis
multiple endocrine neoplasia syndrome
what are three keys in periop management of DM
normal glucose, electrolytes, and volume
what medication should be avoided in patients with HYPERkalemia
succs
use ROC
what med can decrease cortisol levels and suppress hyperglycemic response to surgery
midazolam
what opioid if preferred in DM pt with kidney disease
fentanyl
true or false: pain can lead to increased glucose levels in DM patient
TRUE
true or false: metformin and ace inhibitors should be avoided periop in DM patient
TRUE
what electrolyte imbalances may need treatment post op parathyroid surgery
HYPOcalcemia
HYPOmagnesemia
what patient population is more likely to have hypoglycemia during surgery
geriatric patients
who has an increased allergic reaction risk to protamine
fish allergy
vasectomy
DM
what are the indirect Xa inhibitors
LMWH
heparin
what are the direct IIa inhibitors
bivalirudin
argatroban
dabigatran
what are the direct Xa inhibitors
rivaroxaban
apixaban
what are the indirect IIa inhibitors
heparin