Exam 2 part II Flashcards
when succinylcholine is metabolized by _________________________, it produces the active metabolite _______________________.
pseudocholinesterase; succinylmonocholine
DOA of succinylcholine
10 minutes; with full recovery within 12-15 min (normal Tv breathing)
ED95 of succinylcholine
0.3 - 0.5 mg/kg
ED95 of muscle relaxants refers to what ?
a decrease in 95% of twitch height comparing twitch one to twitch four
adult dose of succinylcholine (IV)
0.5-1.5 mg/kg
pediatric IV dose of succinylcholine
2.0 - 2.5 mg/kg
pediatric IM dose of succinylcholine
4-5 mg/kg
when would you typically give succinylcholine to pediatric patients IM?
if they are experiencing a laryngospasm
succinylcholine will typcially not cause fasciulations in children under age _____________, or in __________________
10; elderly
CNS effects succinylcholine
- fasiculations 2. myalgias 3. increased IOP and ICP
why do pts experience myalgia 2/2 to succinylcholine?
prolonged depolarization of muscle cell causes lactic acid release
respiratory effects of succinylcholine
- apnea 2. vocal cord paralysis 3. relaxation of airway musculature
CV effects of succinylcholine
- increase or decrease in HR 2. profound bradycardia in children 3. adult bradycardia with 2nd dose 4. dysrhythmias 5. hyperkalemia
what is the only muscle relaxant medication that has a ultra rapid onset and ultra short duration of action
succinylcholine
neuromuscular blockade effect of succinylcholine is terminated by its diffusion __________________ from the NMJ
away
GI effects of succinylcholine
- increases intragastric pressure 2. increases lower esophageal tone
T/F: succinylcholine only causes masseter rigidity if malignant hyperthermia is occuring
false; masseter rigidity is a s/e of succinylcholine
if you give a second dose of succinylcholine for an adult, what would expect to happen?
bradycardia
________________ decreases the hydrolysis of succinylcholine via pseudocholinesterase 2/2 decreased metabolism
hypothermia
what drugs decrease pseudocholinesterase (thus would increase the duration of action of succinylcholine)
- echothiophate 2. neostigmine 3. pyridostigmine 4. phenelzine 5. cyclophosphamide 6. metoclopramide 7. esmolol 8. pancuronium 9. oral contraceptives
conditions that decrease pseudocholinesterase levels
- pregnancy 2. severe liver disease 3. acute infections* 4. PE 5. muscular dystrophy* 6. active MI 7. renal failures/uremia 8. elderly males 9. burns * 10. plasmapheresis 11. certain drugs * ones that are most likely to be seen
conditions that increase pseudocholinesterase levels (thus may decrease effects of succ)
- nepritic syndrome 2. thyrotoxicosis* 3. hemochromatosis 4. obese pts with DM* 5. anxiety d/o* *ones most likely to see
pregnancy (at term) decreases pseudocholinesterase levels by ___________% and is d/t ______________
40; increase in pts blood volume (i.e. it gets diluted out)
what is “atypical pseudocholinesterase”
having 1 or 2 abnormal pseudocholinesterase genese
heterozygous atypical pseudocholinesterase
having one normal and one abnormal pseudocholinesterase gene
if your pt has a heterozygous pseudocholinesterase, you would expect your neuromuscular block to be prolonged by _______________
20-30 min
Homozygous atypical pseudocholinesterase
two abnormal pseudocholinesterase genes
if someone has homozygous atypical pseudocholinesterase, you would expect the neuromuscular block to be prolonged by ____________
3-8 hours; would require extended mechanical ventilation
_________________ is a blood tests that determines the presence of normal pseudocholinesterase (i.e. determines how well its working)
dibucaine number
T/F: dibucaine number determines the number of pseudocholinesterase enzymes
false; determines the presence of normal P-AchE, NOT the number
___________________ is a local anesthetic (you will never see clinically) that inhibits normal pseudocholinesterase
dibucaine
Normal pseudocholinesterase will have __________% inhibition by dibucaine
80
heterozygous (atypical) pseudocholinesterase will have _____________ inhibition by dibucaine
40-60%
homozygous (atypical) pseudocholinesterase will have ___________% inhbition by dibucaine
20
Adverse effects of succinylcholine
- dysrhythmias/Bradycardia 2. fasiculations 3. hyperkalemia 4. muscle pain/myalgia 5. increased intragastric pressure & increased lower esophageal sphincter tone 6. increased IOP 7. increased ICP 8. masseter muscle rigidity 9. histamine release 10. MH
which adverse effects of succinylcholine can be diminished with “pretreatment” dose of NDMR
- fasiculations 2. muscle pain/myalgia 3. increased intragastric pressure/increased lower esophageal sphincter tone 4. increased ICP
low doses of succinylcholine typically causes what CV effects?
low HR/BP
high doses of succinylcholine typically causes what CV effects
higher HR/BP & catecholamines
__________________ may experience profound bradycardia with succinylcholine. Pretreat with IV atropine to prevent
children (peds)
if you are going to give succinylcholine to a pediatric pt you would pretreat with __________mg/kg of atropine
0.02
T/F: adults typically do not experience bradycardia with succinylcholine, unless subsequent dose is given
TRUE
dysrhythmias that may be seen with succinylcholine administration
- sinus arrest 2. PVCs 3. AV nodal blockade with jx’al rhythm 4. peaked T waves (d/t hyperK - tx with CaCl)
fasiculations with succinylcholine administration is produced by the _______________ receptors
presynaptic
___________________ are disorganized muscle activity resulting from depolarization of the nerve terminal after succinylcholine administration
fasiculations
fasiculations with succinylcholine are not typically observed in whom?
- children < 10 2. elderly
fasiculations 2/2 succinylcholine administration may cause _______________ in pts with osteoporosis and may worsen pre-existing ____________
pathologic fractures; fractures
what is a “self-taming” dose of succinylcholine
giving a small dose of succinylcholine 1 min prior to the intubating dose to prevent fasiculations (ineffective, no longer used)
succinylcholine will increase potassium levels by _______________mEq/L within __________ min of admin, and will last less than ____________ min
0.5-1.0; 3; 10-15
T/F: administration of succinylcholine is not threatening to potassium levels, if the pts potassium is normal
TRUE
conditions that cause susceptibility to succinylcholine induced hperkalemia
- burn injury 2. severe intra-abdominal infection 3. encephalitis 4. GullianBarre syndrome 5. prolonged immobilization 6. polyneuropathy 7. hemorrhagic shock with metabolic acidosis 8. massive trauma/peripheral denervation 9. SCI/transection 10. stroke 11. tetanus 12. ruptured cerebral aneurysm 13. closed head injury 14. myopathies
myalgias and muscle pains 2/2 succinylcholine are most common in what patients
female and inactive
where is the myalgia and muscle pain 2/2 succinylcholine administration typically located
“neck to hips” 1. subcostal region 2. trunk 3. neck 4. upper abs 5. shoulders
how can you prevent/decrease myalgias/muscle pain 2/2 succinylcholine administration
- NDMR pre-tx 2. NSAIDs
myalgia and muscle pain 2/2 succinylcholine typically presents __________ hours after administration, but can last ____________
24-48; 2-7 days
T/F: decreased fasciculations with succinylcholine = decreased myalgias
TRUE
what is the theory behind myalgias and muscle pain 2/2 succinylcholine administration
initial unsynchronized contractions increase myoglobin levels and creatinine kinase (indicates muscle damage/muscle injury)
_____________________ is a rare complication after extensive fasciculation or in malignant hyperthermia
myoglobinemia
why is there an increase in intragastric pressure and LES with the administration of succinylcholine
2/2 the abdominal wall fasiculations
lower esophageal sphcinter may open spontaneously at intragrastric pressure of > ______________ cmH20
28
what can cause increase in IOP and ICP with anesthesia?
- inadequate anesthesia 2. inadequate relaxation (muscle relaxants) 3. stimulation from intubation 4. administration of succinylcholine
