TIVA Flashcards
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
