ITE CA-2 Monitors/machine Flashcards
CVP waveform
CVP waveform
A wave - RA contraction (atrial systole or kick, ventricular diastole)
C wave - Tricuspid bulging
x descent - downward slope of a wave (RA relaxation)
V wave - Filling of RA (ventricular systole)
y descent - downward slope of v wave (RV relaxation and RA emptying); early ventricular filling
standard 1
anesthesia personnel present all times even in MAC
pulse ox based on what law
beer-lambert
cannon a-wave
a-v dissociation
tall a-wave and no y-descent
tricuspid stenosis
MAC is only valid at
pressure of 1 atmosphere or 760 mmHg
increased diameter of the tubing does what to a-line frequency
increase natural frequency
decreased cannula length does what to a-line frequency
increase natural frequency
decreased tubing compliance does what to a-line frequency
increase natural frequency
decreased fluid density in the system does what to a-line frequency
increase natural frequency
overdamping of the a-line will lead to ______ of true art syst BP
underestimation
pules ox 90% = what paO2
60
method of detecting relies on unpaired electrons in outer shell
paramagnetic oxygen analysis
safety system between machine and hospital line
DISS
independent of drug plasma concentration
zero order
increased sample size will ______ the possibility of making type 2 error
decrease
ACCORDING TO NATIONAL INSTITUTE FOR OCCUPATIONAL SAFETY AND HEALTH (NIOSH), WHAT IS THE MAXIMUM TRACE CONCENTRATION OF VOLATILE ANESTHETIC CONTAMINANT PERMITED IN THE OPERATING ROOM WHEN ADMINISTERED IN CONJUNCTION WITH NITROUS OXIDE?
0.5 ppm
ACCORDING TO NATIONAL INSTITUTE FOR OCCUPATIONAL SAFETY AND HEALTH (NIOSH), WHAT IS THE MAXIMUM TRACE CONCENTRATION OF NITROUS OXIDE CONTAMINANT PERMITTED IN THE OPERATING ROOM?
25 ppm
WHAT IS THE CORRECT PRESSURE (PSI) AND VOLUME (L) OF OXYGEN DELIVERED TO THE PATIENT WHEN THE FLUSH VALVE IS PRESSED?
55 PSI/50L
what type of circuit is modern day breathing system
semi-closed
draw the anesthesia machine diagram and label it
draw it
color codes
oxygen - green air - yellow nitrous - blue CO2 - gray helium - brown
prevents incorrect connection from hospital to machine
diss
prevents incorrect connection from cylinder to machine
piss
maximum halogenated agent allowed in OR
2 ppm
draw diagram of scavenging system
draw it
oxygen tank PSI
2000
O2 tank L
625
air tank PSI
1800
air tank L
625
Nitrous tank PSI
745
Nitrous tank L
1590
CO2 tank PSI
840
CO2 tank L
1500
Helium tank PSI
1600
Helium tank L
500
best mapelson spontaneous
A
best mapelson controlled
D
fail safe valve
THE FAIL-SAFE VALVE ‘SHUTS OFF’ OR PROPORTIONALLY DECREASES THE FLOW OF ALL GASES WHEN PRESSURE IN THE OXYGEN DELIVERY LINE DECREASES BELOW 15 P.S.I.
Poiseuille’s law
Laminar flow
Q = (P pi r^4)/(8 visc L)
Reynolds number less than 2300
laminar flow
reynolds number greater than 3000
turbulent flow
reynolds equation
Re = (densityvelocityL)/(viscosity)
a scavenging system that vents waste gas to the atmosphere passively is known as a ____ system
open
YOU NOTICE THAT THE TRANSFER TUBING OF THE SCAVENGING SYSTEM IS KINKED PROXIMAL TO THE POSTIVE PRESSURE RELIEF VALVE. WHICH OF THE FOLLOWING WILL RESULT FROM THE KINK?
barotrauma
flow meters
FLOWMETERS ON THE ANESTHESIA MACHINE PRECISELY CONTROL AND MEASURE GAS FLOW TO THE COMMON GAS OUTLET.
BARALYME DIFFERS FROM SODA LIME BY THE ADDITION OF _______
BARALYME DIFFERS FROM SODA LIME BY THE ADDITION OF BARIUM HYDROXIDE.
open circle system
fresh gas flow from atmosphere
semi-open circle system
increased fresh gas flow with NO rebreathing
semi-closed circle system
decreased fresh gas flow with SOME rebreathing
closed circle system
fresh gas flow matches patient consumption (complete rebreathing)
oxygen supply failure alarm
alarms within 5 seconds of increased/decreased o2
YOU NOTICE THAT THE TRANSFER TUBING OF THE SCAVENGING SYSTEM IS KINKED DISTAL TO THE POSTIVE PRESSURE RELIEF VALVE. WHICH OF THE FOLLOWING WILL RESULT FROM THE KINK?
excess pressure vented from anesthesia machine
PRESSING THE OXYGEN FLUSH VALVE bypasses what
PRESSING THE OXYGEN FLUSH VALVE DOES NOT BYPASS THE PRESSURE REGULATORS BUT DOES BYPASS THE FLOWMETERS.
what is the only safety device located after the flowmeters
oxygen analyzer
how many liters are left in nitrous tank when PSI starts to decrease
400
WHICH STATEMENT ACCURATELY DESCRIBES THE FUNCTION OF THE COMMON GAS OUTLET CHECK VALVE ON THE ANESTHESIA MACHINE?
confirms anterograde flow
THE SCAVENGING SYSTEM RESERVOIR BAG SHOULD INFLATE DURING _______ AND CONTRACT DURING _____.
THE SCAVENGING SYSTEM RESERVOIR BAG SHOULD INFLATE DURING EXPIRATION AND CONTRACT DURING INSPIRATION.
WHICH STATEMENT ACCURATELY DESCRIBES THE FUNCTION OF THE VENTILATOR DISCONNECT ALARM ON THE ANESTHESIA MACHINE?
senses inspiratory airway pressure
thorpe tube cross sectional area
increases from bottom to top
are flow meters gas specific
yes
A ____________ VALVE PREVENTS RETROGRADE FLOW OF GAS FROM THE ANESTHESIA MACHINE OR THE TRANSFER OF GAS FROM A COMPRESSED GAS CYLINDER AT HIGH PRESSURE INTO A CONTAINER AT LOW PRESSURE.
check
_______ technique can be used to detect intraoperative “awareness” (meaning connected consciousness) independently of postoperative explicit recall.
The isolated forearm technique can be used to detect intraoperative “awareness” (meaning connected consciousness) independently of postoperative explicit recall.
Why some absorbents more risk for CO
Unlike older carbon dioxide absorbents, newer absorbents containing calcium hydroxide and calcium chloride (e.g. Amsorb ®) lack strong bases that react with volatile anesthetics to produce carbon monoxide.
First thing in power failure
If a power failure occurs in the operating room the provider should switch to the red plate electrical supply system, which is the emergency power system in the United States. Nearly all life-support devices, including the anesthesia machine, have battery backup capability and will continue to function.
Back up power kicks in within
When the power fails, a sensor will detect this and trigger a transfer switch that will activate an internal emergency generator that should supply the red face plates within 15 seconds.
Hypocalcemia on EKG
Hypocalcemia prolongs phase 3 of the cardiac myocyte action potential which lengthens repolarization time. These effects can manifest as a prolongation of the QT interval on ECG.
Myocyte action potential
Recall that the standard myocyte action potential is made up of five phases. Phase 0 is a fast inward depolarizing current caused by opening of sodium channels. Phase 1 is the partial repolarization phase caused by inactivation of the sodium channels and a transient outward current of potassium ions. Phase 2 is the plateau during which the membrane slowly repolarizes from opening of sarcolemmal L-type calcium channels (L for long-lasting). Phase 3 involves the completion of repolarization. This occurs due to the outward flow of potassium via two types of ion channels: voltage-gated channels causing a delayed outward potassium current and calcium-activated potassium channels that open due to elevated calcium levels within the sarcoplasmic reticulum (SR).
Causes of wide QRS
Causes of a widened QRS (>0.12 seconds) include left or right bundle branch blocks, hyperkalemia, ventricular rhythm (including V-pacing with a pacemaker), or ventricular preexcitation such as with Wolff-Parkinson-White syndrome
Causes of inverted t waves
Inverted T waves can result from bundle branch blocks, myocardial ischemia/infarction, left ventricular hypertrophy, pulmonary embolism, and elevated intracranial pressure. They can also be a normal finding in children.
Mapleson F system
Jackson Reese
Bain circuit
A Bain circuit is a modified Mapleson D circuit with coaxial delivery of fresh gas flow. This design has a lower volume of tubing between the fresh gas flow and the patient within the breathing circuit than does a semi closed circle system. The relatively high dead space of the circle system results in slow equilibration of changes in inspired gas concentration.
The Bain circuit allows for more rapid changes in inspired gas concentration compared to the circle system. However, this is one of the only advantages over a circle system.
How prevent microshock
The equipment ground wire is the most reliable means to prevent microshock. The ground fault interrupter can prevent macroshocks, but does not reliably prevent microshocks.
risk of microshock
v-fib
GFCI
A ground fault circuit interrupter (GFCI) is a device placed to monitor current imbalance in grounded circuits. The GFCI monitors current flow on both the “hot” and “neutral” wires, which should be equal. The GFCI breaks current flow if there is a current imbalance between the two, suggesting an alternate grounds. This is not the best method for prevention of microshock as its threshold value is closer to 5 milliamps, which is several fold above that required for microshock.
A line isolation monitor (LIM)
A line isolation monitor (LIM) is a monitor used to measure the total leakage current of the non-grounded isolated power circuit that exists in the operating room. The threshold for alarm is somewhere between 2-5 milliamps, which is again well above that needed to cause microshock. However, the LIM may be useful in preventing macroshock.
When use curvilinear probe
The curvilinear probe is a low-frequency ultrasound probe which provides deeper penetration than a linear probe.
i.e. gluteal sciatic nerve block
order of circle system components
y piece expiratory valve overflow (popoff) valve CO2 absorber fresh gas flow inspiratory valve y piece
Boyle’s law
water Boyle’s at a constant temperature and Prince Charles is under constant pressure to be king
Boyle’s law: P1V1 = P2V2 or P ∝ 1/V (at constant temperature and mass of gas)
Charles’ law: V1/T1 = V2/T2 or V ∝ T (at constant pressure and mass of gas)
Gay-Lussac’s law: P1/T1 = P2/T2 or P ∝ T (at constant volume and mass of gas)
Henry’s law: C = kP or C ∝ P (at constant temperature)
Dalton’s law: PTotal = P1 + P2 + P3 + …+ Pn
Charles’ law
Note that Charles’ law is similar to Gay-Lussac’s law: Charles’ law states that the volume of a given mass of gas is directly proportional to its temperature when at a constant pressure: V1/T1 = V2/T2 or V ∝ T.
Boyle’s law: P1V1 = P2V2 or P ∝ 1/V (at constant temperature and mass of gas)
Charles’ law: V1/T1 = V2/T2 or V ∝ T (at constant pressure and mass of gas)
Gay-Lussac’s law: P1/T1 = P2/T2 or P ∝ T (at constant volume and mass of gas)
Henry’s law: C = kP or C ∝ P (at constant temperature)
Dalton’s law: PTotal = P1 + P2 + P3 + …+ Pn
Gay-Lussac’s law
Note that Charles’ law is similar to Gay-Lussac’s law: Charles’ law states that the volume of a given mass of gas is directly proportional to its temperature when at a constant pressure: V1/T1 = V2/T2 or V ∝ T.
Boyle’s law: P1V1 = P2V2 or P ∝ 1/V (at constant temperature and mass of gas)
Charles’ law: V1/T1 = V2/T2 or V ∝ T (at constant pressure and mass of gas)
Gay-Lussac’s law: P1/T1 = P2/T2 or P ∝ T (at constant volume and mass of gas)
Henry’s law: C = kP or C ∝ P (at constant temperature)
Dalton’s law: PTotal = P1 + P2 + P3 + …+ Pn
Henry’s law
Henry’s law indicates that at a constant temperature, the concentration of a gas dissolved in a solution is directly proportional to the partial pressure of that gas: C = kP (where k is a solubility constant) or C ∝ P. As the volume percentage of a volatile anesthetic is increased, the alveolar partial pressure increases. An increased alveolar partial pressure, therefore, leads to an increased concentration of the volatile anesthetic in the blood which increases the speed of induction and depth of anesthesia.
Boyle’s law: P1V1 = P2V2 or P ∝ 1/V (at constant temperature and mass of gas)
Charles’ law: V1/T1 = V2/T2 or V ∝ T (at constant pressure and mass of gas)
Gay-Lussac’s law: P1/T1 = P2/T2 or P ∝ T (at constant volume and mass of gas)
Henry’s law: C = kP or C ∝ P (at constant temperature)
Dalton’s law: PTotal = P1 + P2 + P3 + …+ Pn
Dalton’s law
Boyle’s law: P1V1 = P2V2 or P ∝ 1/V (at constant temperature and mass of gas)
Charles’ law: V1/T1 = V2/T2 or V ∝ T (at constant pressure and mass of gas)
Gay-Lussac’s law: P1/T1 = P2/T2 or P ∝ T (at constant volume and mass of gas)
Henry’s law: C = kP or C ∝ P (at constant temperature)
Dalton’s law: PTotal = P1 + P2 + P3 + …+ Pn
The Nd-YAG laser
The neodymium:yttrium-aluminum-garnet Nd-YAG laser is a general-purpose laser that thermally coagulates several millimeters of tissue upon exposure. The light passes through the cornea but can permanently damage the retina within milliseconds of exposure. Protective eyewear with green filters should be worn to prevent eye damage.
Most lasers damage what part of eye
retina
what type of laser damages cornea
carbon dioxide
laser causes most fires
carbon dioxide bc most common for airway surg
what filter color lens for type of laser CO2 Argon Krypton Nd:YAG KTP-Nd:YAG
CO2 - clear Argon - amber-orange Krypton - amber-orange Nd:YAG - green KTP-Nd:YAG - Red
Increase in cardiac output would be expected to increase/decrease the rate of rise in FA/FI for relatively soluble/insoluble inhaled agents
Increase in cardiac output would be expected to decrease the rate of rise in FA/FI for relatively soluble inhaled agents, but would not produce much effect for insoluble agents.
The gases with the highest/lowest solubilities in blood will have the fastest rise in FA/FI
The gases with the lowest solubilities in blood (e.g. desflurane) will have the fastest rise in FA/FI
The first sign of a hypoxic mixture being delivered will be alarming of
The first sign of a hypoxic mixture being delivered will be alarming of the oxygen analyzer.
first stage regulator
The oxygen pipeline and tanks have different inlet pressures, allowing the higher pressured pipeline to be preferentially used by the machine when it is functioning properly (pipeline pressure is 50-55 psig, cylinder pressure is 40-45 psig). Pressure and a mechanical switch determine which (pipeline or tank) is preferentially chosen. Thus, this system operates as usual during a power failure. This “switch” is known as the first stage oxygen regulator; when the higher pipeline pressure is sensed, it will close this regulator preventing the flow of oxygen from the tank. It is important to realize when heavy use occurs, the pipeline pressure may fall and oxygen would be drawn from the tank, which can drain the supply. This is one of the reasons for keeping the cylinder tanks in the off/closed position.
Oxygen supply failure alarm
Most modern machines are equipped with an oxygen supply failure alarm, also known as a fail-safe system. This alarm system will sense when oxygen supply pressure falls below a certain level, generally 30 psig, and creates an audible alarm. This alarm will continue to sound until the pressure is sensed to return above the preset level. The fail-safe system operation depends on the specific anesthesia machine, however, the theory is that at low (or zero) oxygen supply pressures only oxygen can be delivered to the common gas outlet. When the supply pressure of oxygen is adequate, other gases can be used. This safety mechanism does not ensure oxygen flow at the flowmeter, instead, it ensures adequate supply pressure. Therefore, 100% nitrous can be administered as long as the machine has adequate oxygen supply pressure. This is why the proportioning system is needed to prevent the 100% nitrous oxide scenario.
The hypoxic guard, or proportioning system
The hypoxic guard, or proportioning system, is the system that links oxygen flow to nitrous oxide flow to prevent a hypoxic mixture. These systems are pressure and flow based, thus a crossover will still cause a hypoxic mixture. For example, if the guard allows 80% nitrous oxide and 20% oxygen, then 100% nitrous oxide would be delivered in the above scenario involving nitrous oxide into the oxygen pipeline.
An oxygen analyzer
An oxygen analyzer is present in the patient circuit through the inspiratory limb and has become a standard of care for all modern anesthesia machines in the United States. This could potentially be the first sign of a hypoxic gas mixture being delivered thus should always be checked to be functioning properly via the machine check. In the above pipeline crossover, where nitrous oxide replaces oxygen in the pipeline, the oxygen analyzer will be the very first alarm that a hypoxic mixture occurs. Another scenario would be the addition of helium to a circuit, which could dilute oxygen in the circle system after the fail-safe system and hypoxic guard systems. The oxygen analyzer will alarm prior to the patient’s pulse oximeter decreasing unless the patient has preexisting lung disease or an abnormal pulse oximeter reading to begin with.
The management steps for loss of pipeline pressure
The management steps for loss of pipeline pressure are the same as those for pipeline crossover:
1) Open the emergency oxygen cylinder fully (not just the three or four quick turns used for checking).
2) Disconnect the pipeline connection at the wall because something is wrong with the oxygen pipeline.
3) Ventilate by hand with the anesthesia breathing circuit, rather than with the mechanical ventilator (which may use cylinder oxygen for the driving gas if the pipeline is unavailable).
light absorption by wavelength
A mnemonic to help recall light absorption by wavelength is SeXy DARLing: at SiX hundred wavelength, Deoxyhemoglobin Absorbs Red Light.
Blood PCO2 is measured by
Blood PCO2 is measured by a Severinghaus electrode using a method that builds upon the pH electrode mechanism. Carbon dioxide from the blood sample equilibrates across a semipermeable membrane with a bicarbonate solution. The reaction generates H+ ions and the PCO2 is determined by the degree of pH change resulting from the H+ ion generation.
Blood PO2 is measured by
Blood PO2 is most commonly directly measured by a Clark electrode which detects the amount of current that flows between the two electrodes (amperometric). Oxygen from the blood sample diffuses across a semipermeable membrane and is reduced at the cathode, resulting in a reaction that produces a measurable current that is directly proportional to the PO2.
Blood pH is directly measured using
Blood pH is directly measured using an optical absorbance technique or a pH electrode. The latter measures the potential difference between a measuring electrode (which contains the blood sample in contact with a special glass membrane permeable only to H+ ions) and a reference electrode with a stable, known pH.
The fail-safe system
The fail-safe system measures oxygen supply pressure. When the pressure falls (usually below 20-30 psig; normal oxygen supply pressure is 40-60 psig), or if the oxygen flow falls below a certain amount (e.g. 200 mL/min) the fail-safe system shuts off the flow of nitrous oxide (and sometimes other gases, depending on the machine). This helps prevent a decrease in the oxygen concentration of the fresh gas leaving the common gas outlet. Additionally, the fail-safe system includes an alarm for when oxygen supply pressure falls (again, usually ≤20-30 psig). Since the fail-safe system is within the high-pressure system of the anesthesia machine, it will not alarm in response to a flowmeter leak since the flowmeters are in the low-pressure system.
how does NIBP work
The point of maximal amplitude of oscillations corresponds to the mean arterial pressure (MAP). The values of systolic and diastolic pressures are determined using formulas that detect the rate of change in the oscillations.
The High-pressure circuit contains
The High-pressure circuit consists of those parts which receive gas at cylinder pressure
- hanger yoke (including filter and unidirectional valve)
- yoke block
- cylinder pressure gauge
- cylinder pressure regulators
The Intermediate pressure circuit contains
The Intermediate pressure circuit receives gases at low, relatively constant pressures (37-55 psi, which is pipeline pressure, or the pressure downstream of a cylinder regulator)
- pipeline inlets and pressure gauges
- ventilator power inlet
- Oxygen pressure-failure device (fail-safe) and alarm
- flowmeter valves
- oxygen and nitrous oxide second-stage regulators
- oxygen flush valve
The Low-pressure circuit contains
The Low-pressure circuit includes components distal to the flowmeter needle
- valves
- flowmeter tubes
- vaporizers
- check valves (if present)
- common gas outlet
The following are characteristics of Line isolation Monitors (LIM):
The following are characteristics of Line isolation Monitors (LIM):
1) Monitors the integrity of the ungrounded power source in the operating room.
2) The primary circuit is attached to ground, but the secondary circuit is not.
3) The LIM alarms when the leakage current is greater than 5 milliamps.
4) A first fault is not a shock hazard, but a second fault is a hazard to operating room personnel.
Line isolation montor alarm
If there is an alarm after the procedure has begun, the most appropriate next step is to unplug the electrical device which was most recently plugged in.
Type of heat loss from the breathing circuit
Heat loss through the breathing circuit can be explained by evaporation; for this reason, inspired gases, particularly in vulnerable pediatric patients, are humidified to minimize this loss. For anesthesia machines, a heat-moisture exchanger (HME) is commonly used.
Best ways to measure volume status
Static measurements (CVP, wedge pressure) are not reliable indicators of volume status. Dynamic measurements such as arterial pressure variation, which includes SVV and PPV, are more reliable indicators. The typical SVV cutoff used is 13%
CVP waveform in afib
The central venous pressure tracing contains three systolic components (c wave, v wave, x descent) and two diastolic components (a wave, y descent). In patients with atrial fibrillation, two characteristic findings are the loss of the a wave and a prominent c wave.
The pulse pressure (PP = SBP - DBP) ________ as the cuff is moved distally.
what is estimated by NIBP cuff
The automated sphygmomanometer most accurately estimates the mean arterial pressure (MAP), which is at the point of maximum amplitude of oscillations. The pulse pressure (PP = SBP - DBP) increases as the cuff is moved distally.
The order of accuracy for automated sphygmomanometers is
The order of accuracy for automated sphygmomanometers is MAP > SBP > DBP.
type of ETT material most susceptible to ignition
PVC (polyvinyl chloride)
what does a magnet do to a pacemaker
A magnet would set a permanent pacemaker at a preset asynchronous mode
For pacemaker-dependent patients who have an AICD, placing a magnet will not affect pacing function thus they will need device reprogramming.
Self-limited ventricular arrhythmias are common during placement of a PAC and occur most commonly when the balloon tip passes through the
Self-limited ventricular arrhythmias are common during placement of a PAC and occur most commonly when the balloon tip passes through the right ventricle.
what measures O2
Oxygen concentration is measured via a paramagnetic oximeter, galvanic cell, Clark cell, or polarographic oxygen analyzer
Severinghaus electrode measures CO2.
Sanz electrode measures pH.
what measures CO2
Infrared (IR) absorption spectrophotometry is used to detect volatile anesthetics, CO2, and N2O (C). Each of these gases absorbs a different wavelength of infrared light, and can be used to identify them. This specific method cannot measure oxygen or xenon, as they are non-polar molecules. Contemporary respiratory multigas analyzers use some form of IR spectroscopy to measure carbon dioxide, nitrous oxide, and the potent inhaled anesthetic agents.
what measures volatiles
Infrared (IR) absorption spectrophotometry is used to detect volatile anesthetics, CO2, and N2O (C). Each of these gases absorbs a different wavelength of infrared light, and can be used to identify them. This specific method cannot measure oxygen or xenon, as they are non-polar molecules. Contemporary respiratory multigas analyzers use some form of IR spectroscopy to measure carbon dioxide, nitrous oxide, and the potent inhaled anesthetic agents.
what measures N2O
Infrared (IR) absorption spectrophotometry is used to detect volatile anesthetics, CO2, and N2O (C). Each of these gases absorbs a different wavelength of infrared light, and can be used to identify them. This specific method cannot measure oxygen or xenon, as they are non-polar molecules. Contemporary respiratory multigas analyzers use some form of IR spectroscopy to measure carbon dioxide, nitrous oxide, and the potent inhaled anesthetic agents.
what measures CO2
Clark, galvanic, and paramagnetic electrodes measure oxygen.
Severinghaus electrode measures CO2.
Sanz electrode measures pH.
what measures pH
Clark, galvanic, and paramagnetic electrodes measure oxygen.
Severinghaus electrode measures CO2.
Sanz electrode measures pH.
The Avogadro law
The Avogadro law states equal volumes of all gases at the same pressure and temperature will contain the same number of molecules.
high, medium, low pressure portions of anesthesia machine, what is in each one
Gas supply for anesthesia machines can be divided into high-pressure, intermediate-pressure, and low-pressure sections. The high-pressure section includes auxiliary E cylinders, which are drawn from when there is pipeline failure. Intermediate-pressure includes the hospital pipeline supply and portions of the anesthesia machine with pressures reduced by secondary pressure regulators in the 15-30 psig range. The low-pressure section begins at the flow control valves and includes the flowmeters, vaporizers, and fresh gas supply line.
what is the ETT cuff made of
Endotracheal tube (ETT) cuffs made from ultra-thin polyurethane have been shown to prevent liquid flow around an endotracheal tube (ETT) cuff while inflated to only 15 cm H2O, and thus are the most likely of the answer choices to be incorporated into modern ETTs.
what is the ETT made of
PVC polyvinyl chloride
standard universal ventilating circuit adapter size
15mm or 22mm, usually 15
open waste gas scavenging interface
and required vacuum rate
An open waste gas scavenging interface does not utilize positive-pressure or negative-pressure relief valves but is instead open to the atmosphere. Because of this, the vacuum rate within the canister must exceed the rate of waste gas flow into the reservoir chamber. Inadequate vacuum flow will result in waste gas spilling into the procedural environment through the atmospheric ports.
Near-infrared spectroscopy (NIRS)
Near-infrared spectroscopy (NIRS) utilizes longer wavelengths of light to penetrate deeper into tissue and analyze the tissue oxygenation of a larger volume of tissue than visible light spectroscopy (VLS). NIRS measures primarily venous saturation, a deviation of greater than 20% from baseline may raise concerns for decreased cerebral oxygen delivery.
The following findings on capnography are suggestive of (but not specific for) an incompetent inspiratory valve and should prompt the examination of the valve.
The following findings on capnography are suggestive of (but not specific for) an incompetent inspiratory valve and should prompt the examination of the valve.
1) Elevated inspired carbon dioxide baseline, indicated by red markings in figure below.
2) Prolonged expiratory plateau, orange markings below.
3) Gradual (instead of sharp) inspiratory down stroke, orange markings below.
blood cooled to room temperature will have a
Because partial pressure is proportional to temperature, blood cooled to room temperature will have a lower PaO2, lower PaCO2, and higher pH compared to body temperature.
