Exam 3 part V

Question 1

which concentration of epi would have a higher plasma concentration @ 1mL (thus increased risk of toxicity) - 1% or 2%

Answer 1

2% ; 2% = 20 mg/ml which is a higher DOSE than 1%. plasma concentration of LA is directly proportional to the dose

Question 2

plasma concentration of lido is directly proportional to the ________________

Answer 2

dose

Question 3

all LA anesthetics cause vasodilation –> increased absorption, decreased DOA, and increased risk of toxicity EXCEPT _____________, __________, _____________

Answer 3

cocaine (inhibits reuptake of NE) lidocaine ropivicaine

Question 4

what is the rapid phase of the two compartment model (for LA)

Answer 4

highly perfused tissues (VRG) reach equilibrium quickly

Question 5

what is the slow phase of the two compartment model (for LA)

Answer 5

equilibrium of lesser perfused tissues happens slower

Question 6

which tissue group recieves the highest concentration of LA from redistribution

Answer 6

muscle group

Question 7

order of distribution of LA throughout the body

Answer 7

1. VRG 2. muscle group 3. fat group 4. vessel poor group

Question 8

saturated, inhibited, or atypical p-AchE can _______________ the 1/2 life of __________ LA

Answer 8

prolong; ester

Question 9

all amide LA are metabolized by the hepatic biotransformation via CYP450 except __________________, which is metabolized via _____________________

Answer 9

articaine; plasma cholinesterase

Question 10

T/F: poorly functioning P-AchE effects DOA of ester LA

Answer 10

false; the absorption away from the site of action remains unchanged

Question 11

Amides should be avoided in patients with ____________________

Answer 11

renal failure

Question 12

if pt has hepatic dysfunction you should _______________ single dose and ____________ infusions of amide LA

Answer 12

make no adjustment; decrease by 10-50%

Question 13

during pregnancy, women will have increased ______________ & __________ of the LA with spinals and epidurals

Answer 13

spread; depth

Question 14

why do pregnant women have increased spread and depth of LA with spinals and epidurals

Answer 14

1. decreased thoracolumbar CSF 2. increased susceptibility to LA d/t increased progesterone 3. gravid uterus = dilated epidural veins = narrowed SA and epidural space

Question 15

modification to dose of LA in spinals and epidurals for pregnant women

Answer 15

you decrease dose

Question 16

T/F: epi markers will prolong the DOA to the same extent with all LA

Answer 16

FALSE

Question 17

purpose of epi additives to LA

Answer 17

1. used to detect intravacular injection with PNB and epidurals 2. prolongs the intensity of the block 3. increases safety, quality, rate of onset, and reduced blood loss

Question 18

epi markers in LA will have much more pronounced effects with ____________acting LA

Answer 18

short

Question 19

how do epi markers prolong the intensity of the LA

Answer 19

local vasoconstriction which: 1. decreases rate of vascular absorption 2. decreases risk of toxicity 3. increases the LA available at the site

Question 20

what is the typical concentration of epi with LA

Answer 20

1:200,000 (5 mcg/mL)

Question 21

when testing an epidural catheter you are going to place _________ cc of LA + epi, and if you are in the right place, ______________ will happen

Answer 21

3; nothing (no raise in HR, BP, or anesthesia)

Question 22

effect of vasoconstrictive additive on the LA is influenced by:

Answer 22

1. drug (LA and vasoconstrictor) 2. dose of each 3. concentration of each 4. site of injection

Question 23

what vasopressor drugs can be used as additives to LA

Answer 23

1. epi (superior) 2. phenylephrine 3. norepinephrine

Question 24

which vasoconstricting additive is the best for the nerve stimulator technique with peripheral blocks

Answer 24

epi

Question 25

alpha2 adrenergic agonist additives to LA are most effective on ______________ & ____________ fibers

Answer 25

C (sensory); A-delta (motor)

Question 26

MOA of adding alpha 2 agonist to LA

Answer 26

1. effect spinal and supraspinal receptors 2. interrput the nerves ability to achieve resting membrane potential from the inactive state

Question 27

alpha-2 agonists are added to LA for what type of blocks

Answer 27

1. caudal (peds) 2. neuraxial 3. PNB

Question 28

s/e of adding clonidine to LA block

Answer 28

1. hypotension 2. bradycardia 3. sedation

Question 29

______________ mcg of clonidine added to LA will increase analgesic effect by about _______________ minutes

Answer 29

100; 100

Question 30

"updosing an epidural" means that you are adding _________________ to the LA

Answer 30

sodium bicarbonate

Question 31

sodium bicarb is widely used as an additive to LA in ________________ anesthesia

Answer 31

epidural

Question 32

effects of adding sodium bicarb to LA in epidural

Answer 32

1. increases the pH of the solution --> increased non-ionized form of LA 2. with injection more LA crosses the membrane --> increased speed of onset 3. also decreases pain and stinging

Question 33

if adding sodium bicarb to LA you should beware of NaHCO3 ability to __________________

Answer 33

precipitate

Question 34

effect of adding hyaluronidase to LA

Answer 34

increases the spread of LA via facilitating diffusion into the nerve

Question 35

MOA of hyaluronidase

Answer 35

enzyme that hydrolysis hyaluronic acid (which inhibits the spread of substances through tissues)

Question 36

hyaluronidase as an additive to LA is commonly seen with _______________ procedures

Answer 36

opthalamic

Question 37

potential adverse effects of hyaluronidase into LA

Answer 37

1. allergic response 2. shorten DOA 3. increased risk of toxicity

Question 38

what types of blocks can ketamine be added to

Answer 38

1. spinals (intrathecal) 2. epidural 3. PNB

Question 39

what is the effect of adding ketamine to LA for an intrathecal (spinal) injection

Answer 39

1. shortens onset of LA analgesia 2. shortens DOA of analgesia

Question 40

what is the effect of adding ketamine to LA for epidural

Answer 40

effect is unclear

Question 41

what is the effect of adding ketamine to LA for PNB

Answer 41

prolongs post-op analgesia

Question 42

what concentration of ketamine would you expect to add to LA for regional anesthesia?

Answer 42

50 or 100 mg/mL

Question 43

opioids as additive or single agent can only be used for _________________ blocks

Answer 43

neuraxial

Question 44

what is the other name for morphine that is specifically used in neuraxial anesthsia

Answer 44

duramorph - preservative free morphine

Question 45

which opioids can be added or used a sole agent for spinal anesthesia

Answer 45

1. intrathecal morphine 2. intrathecal fentanyl 3. intrathecal sufentanil

Question 46

what is the dose of morphine if used as additive or sole agent in spinal or epidural?

Answer 46

0.1-0.2 mg

Question 47

intrathecal morphine (spinal) can provide analgesia for ____________ hours post C-section

Answer 47

20

Question 48

s/e of intrathecal morphine (duramorph)

Answer 48

pruritus commonly atarax given with it because itching is SO bad

Question 49

dose of intrathecal fentanyl

Answer 49

10-25 mcg

Question 50

effects of intrathecal fentanyl on your block

Answer 50

1. improves spread 2. prolongs block 3. dose dependent effects

Question 51

dose of intrathecal sufentanil

Answer 51

5 mcg

Question 52

5 mcg of intrathecal sufentanil is similar to a _________ mg intrathecal dose of morphine

Answer 52

0.2

Question 53

benefit of intrathecal sufentanil over morphine / fentantyl?

Answer 53

shorter DOA with decreased pruritus

Question 54

epidural morphine is a _________________ shot that is effective for postop analgesia in ________________ & _______________ procedures

Answer 54

single; ortho; OB

Question 55

___________________ with epidural morphine can last longer than analgesic effect, monitor closely and be sure to report that you used it to recovery staff

Answer 55

respiratory depression

Question 56

dose of epidural fentanyl

Answer 56

2 - 10 mcg /mL

Question 57

dose of epidural sufentanil

Answer 57

0.75- 1.0 mcg/mL

Question 58

T/F: IV effects of sufenta = epidural effects of sufenta

Answer 58

TRUE

Question 59

dose of hydromorphone in epidural

Answer 59

20 mcg/mL

Question 60

what opioids can be added or used as sole agent in epidural

Answer 60

1. morphine (single shot) 2. fentanyl 3. sufentanil 4. hydromorphone

Question 61

respiratory depression is a common s/e with opioids in neuraxial anesthesia, but onset varies. place in order from earliest onset to latest onset respiratory depression with epidural opioids

Answer 61

1. sufentanil (earliest onset d/t most lipophillic) 2. fentanyl 3. hydromorphone 4. morphine (latest onset)

Question 62

dose of ketamine for intrathecal block

Answer 62

5-25 mg

Question 63

dose of clonidine for neuraxial or PNB block

Answer 63

max = 1 mg/kg of ideal body weight

Question 64

decadron is commonly added to ________________ blocks

Answer 64

peripheral

Question 65

dose of decadron additive to PNB

Answer 65

2-4 mg

Question 66

dose of precedex in spinal

Answer 66

10 mcg

Question 67

dose of precedex in epidural

Answer 67

0.5 mcg/kg

Question 68

dose of precedex in peripheral nerve block

Answer 68

0.5-1 mcg/kg

Question 69

ion trapping is an effect of LA that can happen with what situations ?

Answer 69

1. respiratory depression, hypoxia, acidosis 2. LA injection into infected tissues 3. storage of LA in acidic solutions 4. LA accumulation into fetal circulation

Question 70

why is there ion trapping of LA with respiratory depression, hypoxia, and acidosis

Answer 70

1. increased ionization of LA within CNS 2. decreases ability of LA to cross BBB out of the brain 3. potential to prolong and enhance CNS toxicity of LA

Question 71

effect of injecting LA into infected tissues

Answer 71

infected tissues are acidotic and have no lipid solubility --> LA ionizing and being ineffective bc it cannot absorb

Question 72

why do you have ion trapping of LA in the fetal circulation

Answer 72

fetal pH is lower than maternal pH --> LA enters fetal blood ionizes and is trapped in fetal circulation potential for high fetal levels of LA

Question 73

if LA was stored in the non-ionized form what would happen

Answer 73

1. can photodegradgate 2. forms aldehydes --> aldehyde toxicity

Question 74

which agent is MOST likely to cause LAST

Answer 74

bupiv

Question 75

causes of LAST

Answer 75

1. inadvertent IV injection or absorption of large amounts of drugs 2. occasionally d/t continuous infusions 2/2 accumulation of drug/metabolites over many days 3. high systemic blood levels

Question 76

single injection LA will have onset of LAST within ____________ minutes; continuous infusions it will take __________________ before see sx

Answer 76

5 (but as fast as 30-60 s); hours or days

Question 77

LAST occured most commonly in which type of block?

Answer 77

single shot epidurals

Question 78

LAST prevention

Answer 78

1. test doses 2. incremental dosing 3. using pharmacologic biomarkers (epi) 4. restricted use of 0.75% bupiv in OB 5. use the lowest dose possible

Question 79

sx of LAST

Answer 79

1. lightheadedness 2. tinnitus 3. circumoral and tongue numbness 4. metallic taste 5. visual disturbances 6. muscle twitching 7. unconsciousness/convulsions 8. coma 9. respiratory arrest 10. CVS depression

Question 80

which agents cause CV depression the most (with LAST)

Answer 80

1. bupiv ** (MOST) 2. tetracaine 3. etidocaine

Question 81

systemic blood levels of LA vary with?

Answer 81

1. area of blockade 2. technique 3. specific drug used

Question 82

if performing regional anesthesia you should always be prepared to manage what complication?

Answer 82

LAST

Question 83

tx of LAST

Answer 83

1. airway management - 100% FiO2 2. seizure suppression - BZ 3. BLS/ACLS 4. infuse 20% lipid emulsion 5. call cardiopulmonary bypass team & make arrangements for the possibility it is needed 6. keep epi doses < 1 mg/kg

Question 84

if you suspect LAST and your patient goes into cardiac arrest, what drugs should be avoided

Answer 84

1. vasopressin 2. CCB 3. BB 4. LA 5. propofol (if pt is grossly HD unstable)

Question 85

if you perform a regional block, you should consider LAST in any pt with:

Answer 85

1. altered mental status 2. neurologic sx 3. CV instability

Question 86

T/F: propofol is a substitute for lipid emulsion therapy in tx'ing LAST

Answer 86

FALSE

Question 87

effects of 20% lipid emulsion with LAST tx

Answer 87

1. lipid sink - captures LA in blood 2. metabolic effect - increases fatty acid uptake 3. membrane effect - interference with LA binding to VG Na channel 4. cytoprotection - activation of the Akt cascade 5. ionotropic effect - promotes Ca entry via VG Ca channels 6. pharmacokinetic effect - accelerated shunting

Question 88

recommended dosing of 20% lipid emulsion in Tx of LAST

Answer 88

DOSING ON LEAN BODY MASS 1. initiate IV bolus of 1.5 cc/kg 2. continue infusion at 0.25 cc/kg/min x 10 min after return of cardiac fx 3. if CV instability continues, consider repeating bolus and increasing infusion to 0.5 cc/kg/min 4. max = 10 cc/kg over 30 min for initial dosing

Question 89

you can redose the 20% lipid emulsion bolus _____________x

Answer 89

2-Jan

Question 90

T/F: 20% lipid emulsion therapy can be used to treat LAST in pregnant patients

Answer 90

TRUE

Question 91

which LA cause methemoglobinemia

Answer 91

1. benzocaine 2. prilocaine

Question 92

tx of methemoglobinemia

Answer 92

methylene blue 1-2 mg/kg IV over 30 min

Question 93

benzocaine and prilocaine are c/i under the age of __________ 2/2 ability to cause ___________________

Answer 93

2; methemoglobinemia

Question 94

what is methemoglobinemia

Answer 94

when Fe2+ (ferrous form of hgb) is oxidized to form Fe3+ (ferric form of hgb)

Question 95

high concentrations of metHb in the blood causes ________________ & ____________

Answer 95

1. tissue hypoxia 2/2 reduced capacity to carry O2 2. left shift of the oxyhgb curve

Question 96

s/sx of methemoglobinemia

Answer 96

1. cyanosis 2. decreased SaO2 despite O2 tx 3. chocolate colored blood 4. tachypnea/tachycardia 5. confusion 6. HA 7. dizziness 8. coma 9. death

Question 97

cauda equina syndrome

Answer 97

irritation of the sacral spinal cord

Question 98

which LA was responsible for cauda equina syndrome due to inadvertent intrathecal injection

Answer 98

chloroprocaine

Question 99

sx of cauda equina syndrome

Answer 99

1. acute loss of function to the lumbar plexus 2. saddle anesthesia (S3-S5 dermatome) --> pins and needles in perineum, genitals, anus, and lower extremities 3. bowel and bladder dysfunction 4. could be permanent

Question 100

cauda equina syndrome 2/2 LA injection disappeared when they started using ____________________

Answer 100

preservative free solutions