Device, Monitoring, and Physics Flashcards
Allen’s Test
determines collateral blood flow in ulnar and radial arteries before cannulation
Amsorb
[contents]
calcium hydroxide and calcium chloride
Arterial BP Monitoring
[MAP calculation]
mean under pressure curve
Arterial BP Monitoring
[rate of downstroke]
peripheral vascular resistance
Arterial BP Monitoring
[rate of upstroke]
indicates contractility
Baralyme
[absorptive capacity]
10-20 L of CO2 per 100g absorbent
BIS
[suppression ratio]
percentage that an isoelectic condition exists over the prior monitoring time period
Blood Pressure Cuff
[ideal fit]
bladder should extend halfway around the extremity
width should be 20-50% greater than diameter of extremity
Blood Pressure Cuff
[too narrow]
large overestimation of systolic pressure
Capnography
[mechanism]
infrared light
Cardiac Index
[normal range]
2.8 - 4.2
Cardiax Index
[equation]
CO / BSA
(L/min/m2)
Central Venous Catheter
[risk of left internal jugular]
pleural effusion and chylothorax
Central Venous Catheter
[ideal placement]
right internal jugular
- catheter tip should be just superior to superior vena cava
- just above carina on chest x-ray
Central Venous Pressure
[estimation of _____]
right atrial pressure
Circle components
[in addiion to mapleson circuits]
CO2 absorber
unidirectional valves
Y-connector
Rank agents in order of carbon monoxide risk
des > iso > sevo
CO2 Absorbent
[indicator dye]
usually ethyl violet
- turns from white to purple with increasing [H+]
CO2 waveform
[phase 1]
dead space

CO2 waveform
[phase 0]
inspiratory segment

CO2 waveform
[phase II]
alveolar gas and dead space

CO2 waveform
[alpha angle]
related to ventilation-perfusion matching

CO2 waveform
[beta angle]
assess rebreathing
- should be close to 90o
CO2 Waveform
[phase III]
“plateau” of alveolar gas

CO2 waveform
[phase IV]
terminal “upswing” seen in patients with reduced thoracic compliance
- examples: obese and pregnant patients
standard compliance in adult breathing circuits
5 mL/cmH<span>2</span>O
- Thus, if PIP is 20cmH2O, about 100mL of tidal volume is lost to the circuit
decreased CVP and blood pressure
[most likely cause]
decreased venous return
CVP decreases and BP increases
[most likely cause]
increased cardiac performance
At what time is CVP measured?
between A and C waves during end-expiration
CVP measurement
[a waves]
correspond to atrial contraction
- absent in atrial fibrillation
- exaggerated in junctional rhythms
CVP Measurement
[c waves]
tricuspid valve during early ventricular contraction
CVP Measurement
[v waves]
venous return against a closed tricuspid valve
Diameter Index Safety System
prevents incorrect pipeline attachements
E-cylinder
[weight and volume]
63lbs
4.8L
Lead I best measures which coronary artery?
left circumflex
Lead II best measures which artery?
Right coronary artery (RCA)
V5 best represents which coronary artery?
Left anterior descending (LCA)
EKG p-wave
[normal time span]
0.08 - 0.10 sec
EKG PR interval
[normal time span]
0.12 - 0.20 sec
EKG QRS complex
[normal time interval]
0.06 - 0.10 sec
EKG
[waveform amplitude]
1 mV
EKG
[Lead II]
connects right arm to left leg
- parallel to electrical axis of atria
- results in largest p-wave
- enhances diagnosis of arrhythmias and detection of inferior wall ishcemia
EKG
[myocardial ischemia detection]
ST depression exceeding 1mm
- recorded 80 msec after the J point
- best seen in “diagnostic mode”
- may be seen with t-wave inversion
EKG
[V5 lead]
anterior axillary line at 5th intercostal
- detect anterior and lateral wall ischemia
Fractional Concentration of Agent at Vaporizer
(FA)
[equation]
- QV = flow of carrier gas
- QT = total flow of gas
- PA = vapor pressure of agent
- PB = barometric pressure

Fresh Gas Coupling
[definition]
increased tidal volume and PIP with increasing fresh gas flow
- O2 flush should be avoided during inspiratory phase
Recommended gas exposure according to NIOSH
25 ppm N2O
2 ppm agent (0.2 if N2O also present)
Link-25
maintains [O2] by increasing the flow of oxygen

Mapleson A
Mapleson A
[uses]
spontaneous ventilation

Mapleson B

Mapleson C

Mapleson D

Mapleson E

Mapleson F
Mapleson F
[uses]
neonates and small infants
Methemoglobin
[pulse oximetry reading]
85%
- same absorption coefficient at both red and infrared wavelengths, resulting in a 1:1 ratio
Myer Overton Rule
anesthetic potency of inhalational agent correlates directly with their lipid solubility
N2O
[liters in full tank]
1,590
N2O
[tank pressure]
745 psig
O2 Tank
[liters and psig]
660L at 2200 psig
ORMC
[acronym]
Oxygen Ratio Monitor Controller
Oxygen Analyzers
[3 types]
polarographic (Clark electrode)
galvanic (fuel cell)
paramagnetic
Oxygen Ratio Monitor Controller
reduces [N2O]
- Drager
Oxygen
[1L of liquid oxygen equals ____L in gas]
862L
PA Catheter
[contraindications]
left bundle branch block and conditions with increased risk of arrhythmias
- Example: Wolff-Parkinson-White
PA Catheter
[insertion tips and tricks]
- have patient inhale deeply
- head-up, right lateral tilt position
- injet cold saline through proximal lumen
- inotropic agent to increase CO
PA Catheter
[placement distance]
35-45 cm
- should see a sudden increase in diastolic pressure
PA waveform
[causes of large A waves]
a-fib
left ventricular hypertropy
PA waveform
[large V wave]
mitral regurge
Passy-Muir Valve
[definition]
redirects air flow through the vocal folds to enable speaking
Passy-Muir Valve
[errors to avoid]
remove before ventilation
- if left on, will cause repeated inflation of pateint’s lungs without ability to exhale
Peak Inspriatory Pressure
highest circuit pressure generated during inspiration
- dynamic compliance
Pin Index Safety System
prevents incorrect cylinder attachments
Piston Ventilators
[advantages]
delivers accurate tidal volumes
- good for patients with poor lung compliance and infants
Plateau Pressure
pressure measured during inspiratory pause
(time of no gas flow)
- static compliance
Pressure Sensory Shut-off Valve
“fail safe” in Datex
- shuts off other gases when O2 falls below 26psig
- upstream of 2nd regulator
- based on threshold
Pulmonary Artery Catheter
[distance to PAWP]
50 cm
Pulmonary Artery Catheter
[distance to pulmonary artery]
40 cm
Pulmonary Artery Catheter
[distance to right atrium]
20 cm
Pulmonary Artery Catheter
[distance to right ventricle]
30 cm
pulmonary artery measurement
[predictors of pulmonary embolism]
increased PAP, but no change in PAWP
Pulmonary Artery Wedge Pressure
[estimation of _____]
left ventricular end-diastolic pressure
Pulmonary Vasular Resistance
[equation]
(dynes*sec*cm-5)

Pulmonary Vascular Resistance
[normal range]
100 - 250
dynes * sec * cm-5
Pulse Ox
[wavelength absorption]
660 and 940 nm
“any increase in dead space must be accompanied by a corresponding increase in _____, if alveolar ventilation is to remain unchanged”
tidal volume
“An increase in PIP and plateau pressure implies _____ or _____”
increase in tidal volume
or
decrease in pulmonary compliance
“For each mmHg rise in PaCO22, normal awake patients increase their minute ventilaiton by ____ L/min”
2 - 3
- general anesthesia decreases this response, paralysis eliminates it
“an increase in PIP without any change in plateau pressure corresponds to _____”
an incrase in airway resistance or inspiratory gas flow rate
Resuscitation Bags
[disadvantages]
- FiO2 is directly proportional to [O2] and flow rate while inversely proportional to MV
- requires high fresh gas flow
Resuscitation Bag
[key difference compared to other systems]
contains a non-rebreathing valve
Soda Lime
[contents]
calcium-, sodium-, and potassium hydroxide
Soda Lime
[absorptive capacity]
15 - 25 L of CO2 per 100g absorbant
Somatosensory Evoked Potentials (SSEPs)
[purpose]
evaluates ascending sensory tracts
(primarily dorsal spinal column)
Somatosensory Evoked Potentials (SSEPs)
[significant changes]
50% amplitude decrease
and
10% latency prolongation
Somatosensory Evoked Potentials
[commonly monitored peripheral nerves]
ulnar
median
posterior tibial
Stroke Volume
(normal range)
60 - 90
Stroke Volume
[equation]
(CO/HR) * 1000
(mL/beat)
Systemic Vasular Resistance
[equation]
(dynes*sec*cm-5)
- same as total peripheral resistance

Systemic Vasular Resistance
[normal range]
900 - 1400
dynes*sec*cm-5
Thermodilution
[correlation with change]
degree of change is inversely proportional to CO
- temperature change is minimal during high clow
transmural pressure
[equation/definition]
atrial pressure - extracardiac pressure
Baralyme
[contents]
20% barium hydroxide and 80% calcium hydroxide
Oxygen Failure Protection Device
gradually reduces other gases until oxygen supply is lower than 12 psig
- Draeger
- base on proportioning
Primary Pressure Regulator
[change in psi]
2200 psi from cylinder to 45-50 psi
Secondary Regulator
[change in psi of O2 and N2O]
lowers O2 to 14 psi
lowers N2O to 26 psi
Visual Evoked Potentials
[uses]
monitor optic nerve and occipital cortex during resection of large pituitary tumors