Save
Busy. Please wait.
Log in with Clever
or

show password
Forgot Password?

Don't have an account?  Sign up 
Sign up using Clever
or

Username is available taken
show password


Make sure to remember your password. If you forget it there is no way for StudyStack to send you a reset link. You would need to create a new account.
Your email address is only used to allow you to reset your password. See our Privacy Policy and Terms of Service.


Already a StudyStack user? Log In

Reset Password
Enter the associated with your account, and we'll email you a link to reset your password.
focusNode
Didn't know it?
click below
 
Knew it?
click below
Don't Know
Remaining cards (0)
Know
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.

  Normal Size     Small Size show me how

SIUE: Monitoring

Kevin's lecture 10/19 - Inspiratory & Expiratory monitoring

QuestionAnswer
Four key features for monitoring 1.) Proper instrumentation 2.) observation & vigilance 3.) interpretation of data 4.) initiation of corrective therapy
What is Standard I of Anesthesia Monitoring from ASA Qualified personnel continuously present to monitor the patient and make neccessary modification
What is Standard II of Anesthesia Monitoring from ASA Continuously evaluating the patient's oxygenation, ventilation, circulation, and temperature
High tone on alarm usually indicates good perfusion
Low tone on alarm usually indicates poor perfusion
In the anesthesia circuit, what must be measured inspired and expired gases
Just because the concentration of O2 in the anesthesia circuit is measured it doesn't gaurantee what? The adequacy of arterial oxygenation
O2 sensors are located where on the anesthesia limb Inspiratory limb, closer to the machine than patient
O2 sensors protects against hypoxic mixtures
3 types of O2 analyzers 1.) Galvanic cell analyzer 2.) Polargraphic O2 analyzer 3.) Paramagnetic O2 analysis
O2 is considered a highly pragmatic gas - attracted to magnetic energy because of unpaired electrons in their outer shell.
Paramagnetic O2 analyzer Dumbell filled with inert gas and suspended on platinum wire. When O2 is processed through sensor, O2 molecules are attracted to stronger of 2 mag fields - resulting in dumbell rotating. Degree of rotation is directly porportional to the PP of O2.
In the paramagnetic O2 analyzer more current required to keep the in a normal state the higher the % of O2
Galvanic Cell Analyzer O2 analyzer. Electrochem sensor. anode and cathod are immersed in electrolyte solution of potassium hydroxide. Hydroxyl ion migrates to anode where oxidation takes place generating an electrical current proportional to the O2 concentration.
Galvanic Cell Analyzer are recognized for their accuracy
Polarographic O2 analyzer Anode and Cathode are immersed in potassium chloride, molecular O2 is consumed by sensor with an accompanying flow of electrical current directly prop. to O2 concentration
Most common O2 analyzer used in anesthesia Polargraphic O2 analyzer, because its the sensor of choice for measuring dissolved O2 measured in liquids
Which O2 analyzer is most similar to the galvanic O2 analyzer Polargraphic O2 sensor
3 ways to measure expired gas 1.) infrared absorption spectophotometry 2.) mass spectrometry 3.) Raman scattering techniques
Where does the sampling of expired gas occuring at? near the ET tube, closer to patient than the O2 analysis
Infrared Absorption Spectrophotometry IRAS is based on the fact that asymmetric molecules absorb infrared light at specific wavelengths
IRAS CAN detect & measure CO2, N2O, and the inhalation anesthetic agents
Fall back to the IRAS cannot distinguish which specific gas is which. (cannot tell if des or sevo), because all anesthetic vapors absorb infrared light at the same wavelengths
All anesthetic vapors absorb infrared light at the same wavelengths
5 components of IRAS 1.) infrared light source 2.) gas sampler 3.) optical path 4.) detection system 5.) signal processor
IRAS measures the unique energy absorbed by gaes and vaports placed into what? an optical path of infrared beam
IRAS has a memory system that correlates absorbed energy with a predicted concentration based upon the Beer-Lambert Law
Mass Spectrometry expired gas measurement. Gas mixure is bombarded with electrons which break them down into fragments given a mass and charge. Then frags are accelerated into a vaccum passing a magnetic field, they separate by mass & charge which are detected.
In mass spectrometry, there is calculation of ion/mass charge ration based on variance of deflection. Each gas has a specific landing site on the detector plate. Ion impacts are prop to concentration of each gas or vapor
Raman Scattering expired gas monitoring. A high intensity argon laser collides with gas molecules which causes increased vibration of the gas moecules. Can identify O2, CO2, N2, N20 & all volatile anesthetics
Raman scattering advantages can identify 02, CO2, N2, N20, all volatile anesthetics and mixtures of volatile anesthetics. very fast, easy to calibrate.
CO2 monitoring can be useful for detecting alterations in ventilation, cardiac output, distribution of pulmonary blood flow, and metabolic activity
Capnometry measurement of CO2 concentration NUMERICALLY, during inspiration and expiration
Capnogram waveform display, continuous concentration-time display of CO2 concentration during ventilation
Capnography the continuous monitoring (continuous waveforom) of the capnogram
Capnography is important because it identifies changes related to patients physiologic status, used to dx malig. hyperthermia, helps identify equip problems, gold standard for ET tube placement, predicts PaCO2.
What is the gold standard for verifying ET tube placement capnography
Capnometry is determined using infared light, with 2 different wavelengths (2600nm & 4300nm). Control gas is comparted to sample from the circuit and a NUMBER is resulted
Capnogram component A-B valley, or baseline. Represents end of inspiration and the begining of expiration. Considered the initial state of expiration. No CO2 here (why a-b is norm at zero) because of gas sample is from the dead space where is is devoid of CO2
Capnogram component B begining of the upstroke, where CO2 presents itself
Capnogram component B-C Sharp upstroke of exhalation. Gas sampld represent a mix of deadspace & alveolar gas thus measurable CO2 is available
the slope of B-C is determined by the eveness of ventilation & alveolar emptying
Capnogram component C-D the alveolar or expiratory plateau. Normally horizontal.
Capnogram component D highest CO2 value of ETCO2 because at end of plateau before inspiration occurs. best reflection of alveolar CO2.
Capnogram component D-E inspiration begins,steep downstroke (rapid decrease in CO2) fresh gas entrained.
ETCO2 may be inaccurate in the presence of significant V/Q mismatch
If V/Q mismatch ratio is large, from embolism this results in ____ of ETCO2 an decrease in ETCO2 and increase in deadspace
Small tidal volumes may relfect inadequate alveolar ventilation and produce ETCO2 readings that significately underestimate arterial CO2 levels
A waveform on capnography that fails to return to baseline, reveals that the patient is ____? which could be from? retaining CO2. Result of inadequate fresh flows or need to change soda lime absorber (CO2 scrubber).
Following esophageal intubation what will we see on the capnogram a initial slight upstroke of CO2, then waveform goes to zero
sloping of the plateau phase represents a progressing prolongation of expiration, from either an obstruction from V/Q mismatch or can be indicative of COPD, or tube kinking
Sawtooth waves on inspiratory down stroke is a result of cardiac oscillations. common in pediatric patients, or is patient is begining to wake up at end of case.
Curare cleft is what and when is it seen it is a dip in the middle of plateau segment, from spontaneous respiratiory effort. Pt needs more narcs or anesthetic.
PaCO2 is measurement of CO2 in the arteries
PACO2 is measurement of CO2 in the alveoli
In what case might the canogram be not as useful as normal? In a case of pulmonary disease, because CO2 might not diffuse as easily, or ventilation & perfusion are not matched
Capnography provides non-invasive what? continuous, real-time reflection of ventilation
During general anesthesia ETCO2 is typically 5-10mmg LOWER than PaCO2.
So under anesthesia if my ETCO2 is 35, what is the PaCO2 PaCO2 is 40-45mmHg
When might the accuracy of the ETCO2 and PaO2 relationship decrease 1.) maldistribution of V/Q 2.) problems in gas sampling 3.) shallow tidal breaths 4.) prolongation of expiratory phase of ventilation 5.) uneven alveolar emptying
If you have a non-perfused alveoli you will have a higher or lower ETCO2? and a PaCO2 of what? lower ETCO2 reading, and a PaCO2 reading of 0.
If someone has a V/Q mismatch what happens to the PaCO2 - ETCO2 gradient it will increase (meaning there will be more than a 5-10 difference between the two)
Examples of V/Q mismatch? emboli, hypoperfusion sates with reduced pulmonary blood flow, COPD
What is the standard of care for oxygenation monitoring during anesthesia? Pulse oximetry
Pulse oximetry measures pulse rate via plethysmography & oxygen saturation of hemoglobin using spectrophotometry
Most accurate measurement of pulse Ox is when probe is applied to R ear
Goal of pulse ox is to detect early hypoxemia and initated tx before serious complications occur
Pulse ox is based on several premises 1.) color of blood is a function of o2 sat 2.) the change i ncolor resuls from optical properties of Hbg interaction with O2 3.) Oxyhemoglobin:deoxyhemoglobin can be determined by absorption spectrophotometry
pulse oximetry and blood gases assess arterial oxygen
Steps for reading a capnogram 1.) look at y axis (is CO2 norm range 35-45) 2.) look at your x axis (is CO2 returning to baseline with each breath 3.) look at expiratory upstroke and inspiratory downstroke (are they normal?) 4. Look at RR rate (is it normal)
Factors to increase ETCO2 shivering, malignant hyperthermia, increased CO, bicarb infusion, effective tx of bronchospasm, decreased minute ventilation
Factors to DECREASE ETCO2 decreased muscular activity, hypothermia, decreased CO, pulmonary embolism, bronchospasm, incresed minute ventilation
Capnography uses: determine ET vs tracheal intubation, monitor changes in dead space or perfusion, used to dectect ciruit issues and leaks
We would expect and increase in ETCO2 when CO2 production exceeds ventilation
Spectrophotometry of pulse ox based on beer lambers law says at a consant light intentisity and hbg concentration, the intensity of light emitted through tissue is a logarthimic function of the O2 satuaration of the hgb
spectrophotometry of pulse ox includes 2 wavelengths to distinguish between deoxyhemoglobin and oxyhemoglobin. The ratio of deoxyhgb : oxyhbg is determined by measuring the ration of infrared and red light sensed
Oxyhemoglobin absorbs infrared light (940nm)
Deoxyhemoblobin absorbs red light (660nm)
Sa02 is ______ to Sp02 NOT EQUAL
Sp02 will not distinguish between 02 Hb and carboxyhemoglobin or methemoglobin
Methemoglobin Sp02 will measure what and why? Sp02 of 85 because it absorbs infrared and red light equally
Carboxyhemoglobin SpO2 will meausre false high (absorbs light at the same wavelength, normally the infrared oxyhemoglobin is faster)
Factors that decreased pulse ox reliability dyshemoglobins, low CO, anemia, vital dyes (methylene blue & indocarmine), nail polish, ambient liht, light emitting diode variability, motion artifact, background noise
A smokers pulse ox reading is usually a false high, smokers Sp02 is 7 points below what they read
Pulse Ox troubleshooting is red light visible, is there thickening of skin on site, cold or vasoconstriction, pt moving or shivering, surgeon using cautery, room light interference, fake nails or dark polish, is there a pulse?
Oxyhemoglobin dissociation curve measures the relationship of hemoblogin saturation & O2 tension
On the steep part of the oxyhemoblogin curve what predictable correlation exists between PO2 and Sa02
Shifts in the curve to the right or left define changes in the affinity of Hb for O2
Causes of LEFT shift in oxyhemoglobin diss. curve increased pH (alkalosis), decreased temp, decreased PaCO2
Causes of a RIGHT shift in the oxyhemoglobin diss curve decreased pH (acidosis, increased temp, increased PaCO2
normal oyxhemoglobin diss curve predictions of SP02 & Pa02 Sp02 97% = Pa02 97%, Sp02 90% = Pa02 60%, Sp02 80% = Pa02 50%, Sp02 70% = Pa02 40%
If patient is at risk for malignant hyperthermia precautions would be change entire curciut out including CO2 scrubber, run 10L O2 for 60 min prior, use total IV anesthesia if has had MH in the past.
Created by: asaranita
Popular Nursing sets

 

 



Voices

Use these flashcards to help memorize information. Look at the large card and try to recall what is on the other side. Then click the card to flip it. If you knew the answer, click the green Know box. Otherwise, click the red Don't know box.

When you've placed seven or more cards in the Don't know box, click "retry" to try those cards again.

If you've accidentally put the card in the wrong box, just click on the card to take it out of the box.

You can also use your keyboard to move the cards as follows:

If you are logged in to your account, this website will remember which cards you know and don't know so that they are in the same box the next time you log in.

When you need a break, try one of the other activities listed below the flashcards like Matching, Snowman, or Hungry Bug. Although it may feel like you're playing a game, your brain is still making more connections with the information to help you out.

To see how well you know the information, try the Quiz or Test activity.

Pass complete!
"Know" box contains:
Time elapsed:
Retries:
restart all cards