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Flashcards in TIVA Deck (21)
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1
Q

what is a TIVA?

A

anesthesia including IV agents only (pure TIVA)

*may be combined with N2O and regional

2
Q

what is the ideal TIVA drug?

A

ketamine, covers everything (dissociative, analgesic)

*ketamine and propofol combined are good since they offset the cons of each other

3
Q

what are advantages of TIVA?

A
  • smooth induction with minimal coughing, hiccoughing
  • easier control of anesthetic depth
  • rapid, predictable emergence with minimal hangover
  • decreased incidence of emergence delirium (sevo/iso very insoluble, wake up FAST)
  • lower incidence of PONV
  • non triggering for malignant hyperthermia (Succs and volatile agents biggest triggers)
  • ideal for neurosurgery
  • absence of organ toxicity
  • absence of atmospheric pollution
  • avoids side effects of N2O
  • autoregulation of cerebral blood flow maintained
  • decreased bleeding in surgical field
  • improved mucociliary transport
4
Q

what are disadvantages of TIVA?

A
  • increased post op analgesic demands and cost
  • decrease in FVC after operation greater than BAL with sevo
  • cost
  • no effect on emergence delirium, but less analgesics required and decreased PONV
5
Q

what are indications for TIVA?

A
  • malignant hyperthermia susceptible (hx or family hx)
  • cystic fibrosis (mucus makes induction and emergence long for volatiles)
  • airway endoscopies, laryngeal and tracheal surgery (rigid airways cause to pollute room)
  • remote locations, during transportation
  • intracranial HTN (IV anes. agents cerebral vasoconstrictors; decrease CBF, ICP, and CMRO2 opposed to volatiles that cerebral vasodilate)
  • craniotomy (rapid awakening for neuro checks)
6
Q

compare continuous infusion technique vs. intermittent bolus for TIVA

A

continuous infusions

  • minimize swings in levels of drugs seen with bolus
  • can reduce total drug requirement by 25-30%
  • fewer side effects
  • shorter recovery times
  • decreased drug costs
  • provide stable depth of anesthesia

bolus

  • injected quickly
  • rapid onset of unconsciousness
  • side effects of decreased BP and apnea
7
Q

describe propofol

A
  • rapid onset
  • pain on injection (use lidocaine)
  • myocardial effect (don’t use with hypovolemia)
  • apnea (25-30%; even higher with opioids)
  • induction dose reduced with versed, opioids
  • no accumulation (unlike Thiopental) and early restoration of cognitive and psychomotor function
  • reduction in PONV
8
Q

describe ketamine

A
  • only IV anesthetic that can be used as the sole agent for TIVA
  • hypnosis, analgesia, amnesia
  • sympathetic stimulation (good for trauma and hypovolemia UNLESS catecholamines diminished then returns to baseline depressant)
  • HTN, tachycardia, increased ICP, psychologic reactions (no CAD, pulm HTN, neuro; pre treat with versed)
  • good for pulmonary disorders (asthma) and congenital heart babies
  • discontinue 30 min prior to emergence (allow dissociative effect to wear off)
  • increase PONV (unless with propofol)
  • unpleasant hallucinations (pre treat with versed; combine with propofol)
  • salivation (pre treat with glycopyrrolate)
9
Q

describe ketamine and propofol combined

A
  • offsets hemodynamic effects
  • offsets respiratory effects to maintain spontaneous vent
  • propofol offsets PONV and hallucinations
10
Q

how should dosing be mixed with propofol and ketamine?

A
  • mix ketamine with 2mg/ml of propofol
  • induce with 1-2 mg/kg of propofol in mixture
  • give an additional 0.5-1 mg/kg of ketamine after LOC
  • infuse 140-200 mcg/kg/min first 10 mins
  • 100-140 mcg/kg/min for next 2 hours
  • 80-120 mcg/kg/min after 2 hours
  • rate based on propofol
11
Q

describe remifentanil

A
  • rapid onset, potency 5x fentanyl
  • allows high dose opioids w/o delayed recovery, no matter length of infusion time
  • titrates easily
  • increased shivering and post op pain (give analgesic before stopping)
  • less time to emergence and less PONV
  • good for craniotomies for rapid awakening (post op pain, give analgesic in time before stopping) and carotid endarterectomy (no post op pain; rapid awakening)
12
Q

describe maintenance of remifentanil infusion

A
  • turn on a 1 mcg/kg/min
  • never bolus (stiff chest; metabolized too quickly)
  • maintain at 0.1-0.4 mcg/kg/min
  • metabolized rapidly by plasma esterases
  • turn off 5-7 min before extubation
  • start post op analgesia prior to discontinuing remifentanil (recovery 3-5 min SV)
13
Q

describe dexmedetomidine

A
  • used in sedation (not general)
  • anxiolysis and analgesia (no loss of consciousness)
  • prolonged recovery r/t higher doses required for anesthesia (compared to propofol) *good if planned to be post of ventilated
  • reduced need for opioids
  • decreased PONV
14
Q

what is the most reliable sign of inadequate anesthesia?

A

movement

15
Q

describe titration goals

A
  • maintain 1-2 twitches of ToF to allow movement (weak but to see awareness)
  • bispectral index (frontal EEG)
  • anticipate increased requirement during intubation and skin incision
  • anticipate decreased requirement during prep and drape
16
Q

describe method of titration

A
  • if no response for 10-15 min, the infusion rate may be reduced about 20%
  • watch for movement, changes in hemodynamics to determine need to titrate
  • if pt. responds, administer bolus, and increase rate to a point b/w first and second rate
  • except for remifentanil, don’t titrate opioids
  • titrate down to allow SV at the end of surgery (slowly since surgeon still working)
17
Q

what is the context sensitive half time of propofol?

A
  • up to 3 hours: 10 min
  • after 3 hours: 25 min
  • after 8 hours: 40 min
18
Q

what is the context sensitive half time of ketamine?

A

after 8 hours: 50 min

19
Q

what is the CSHT of remifentanil?

A

4 min after any duration

20
Q

what is the CSHT of sufentanil?

A

after 4 hours: 30 min

21
Q

describe target controlled infusion systems

A
  • programs pts. weight, height, age
  • based on a pharmacokinetic model which describes the elimination and redistribution of the drug
  • can titrate predicted blood concentration of the drug as simply as volatile agents for varying levels of surgical stimulation and individual pt. requirements