miscellaneous monitors and equipment Flashcards
what is the best method of assessing deep neuro muscular block
post tetanic count
clinical recovery from NMB happens when TOF achieves
> 0.9
results of TOF will not be accurate for up to ______ after sustained tetany assessment
6 minutes
when to use post tetanic count
to assess depth of NMB when no twitches are present
-6-10 post tetanic twitches suggests T1 will come back at any minute
cerebral oximetry
utilizes what to monitor
measures what O2 sat
utilizes near infrared spectrometry (NIRS)
measures venous O2
regional NOT global monitoring
placement of cerebral oximetry
sensor placed on patients scalp usually over frontal lobe
contains a light emitting diode with two light sensors
what change from baseline suggests a reduction in cerebral oxygenation?
25% change from baseline
classify this brain wave
beta
13-30 cycles/second
high frequency and low voltage
associated with awake mental stimulation and light anesthesia
classify this brain wave
alpha
frequency 8-12 cycles/second
associated with awake but restful state (eyes closed)
classify this brain wave
theta
4-7 cycles/second
associated with GA and children during normal sleep
classify this brain wave
delta
<4 cycles/second
associated with GA, deep sleep, or brain ischemia/injury
classify this brain wave
burst suppression
associated with GA, hypothermia, CPB, and cerebral ischemia (esp if its unilateral burst suppression)
classify this brain wave
isoelectricity. absence of electrical activity associated with very deep anesthesia or death
how brain waves change during anesthesia
what increases beta wave activity
what waves predominate during GA
what is associated with burst suppression
what is associated with isoelectricity
induction and light anesthesia is associated with increased beta activity
theta and delta waves predominate during GA
deep anesthesia produces burst suppression
at 1.5-2 MAC GA causes complete suppression or isoelectricity
which anesthetic agent increases beta wave activity
nitrous oxide alone
which anesthetic agent is associated with epileptiform EEG activity
sevo
(etomidate can produce myoclonus but does NOT produce epileptiform EEG activity)
how does ketamine affect EEG
can increase high frequency cortical activity and may confuse EEG interpretation- the patient may be deeper than the EEG suggests
what EEG waveform is suggestive of cerebral ischemia
unilateral burst suppression
the development of new _______ waves signify the brain is at risk for ischemia
delta waves
when does burst suppression start on BIS
20
as the level of anesthesia becomes deeper, what happens to the physical characteristics of the EEG waveform
lower frequency (slower)
higher amplitude (taller)
what can impair the accuracy of the bis (3)
hypothermia, electromyographic interference, encephalopathy
patient safety index monitor target range for GA
its similar to BIS but target range is 25-50
macroshock voltage and clinical consequences
1mA
5mA
10-20mA
50mA
100mA
microshock voltage and clinical consequences
10uA
100uA
grounded v not grounded
OR supply
equipment
OR supply: not grounded
equipment: grounded
primary purpose of line isolation monitor
ensures OR supply is not grounded but does alert when the OR has become grounded. it will alarm when 2-5mA of leak current is detected
if LIM (line isolation monitor) sounds, what should you do
un plug the last piece of equipment that was plugged in
