108 Questions
What does the ASA Standards for Basic Anesthetic Monitoring emphasize regarding the presence of anesthesia personnel?
It mandates the presence of qualified personnel throughout different types of anesthesia.
What does the concept of respiration include?
Transport of O2 from the environment to body cells and transport of CO2 from body cells to the environment
What does respiratory monitoring refer to?
Continuous or periodic assessment of processes related to respiratory gas exchange
In respiratory monitoring, what is assessed regarding the exchange of gases between the environment and subcellular pathways?
Convective and diffusive gas transport
Where does cellular respiration involve the use of O2 and production of CO2?
Mitochondria
What is the essential role of the physical examination in perioperative respiratory monitoring?
It offers crucial details for diagnosis and treatment, often signaling changes in patient status requiring intervention.
In elective cases, why does the anesthesiologist have the time to investigate causes for abnormal presentations?
Because the procedure is planned, allowing time for further investigation.
What should the observation of respiratory distress prompt in terms of anesthetic management?
Immediate search for specific causes.
How is respiratory rate correlated with disease severity during certain conditions like sepsis?
It is significantly correlated with disease severity.
Which of the following is NOT considered an anatomical sign relevant to respiration during a physical examination?
Wheezing
Which of the following is functional element ?
Difficulty of inspiration and expiration
Why should neck vein distension be examined in patients with respiratory distress?
To assess for a potential cardiovascular contribution to respiratory distress
Why is it important to pay attention to painful respiration in trauma patients?
To detect signs of flail chest, pericardial tamponade, or tension pneumothorax
What influences an anesthesiologist's clinical judgment when auscultating the lungs?
Ambient noise, individual hearing limitations, and stethoscope acoustic properties
Why is a stethoscope of sufficient quality important in identifying breath sounds?
To recognize normal and abnormal breath sounds distinctly
Why is a clear understanding of acoustic mechanisms for various breath sounds essential?
To ensure an accurate clinical evaluation based on sound characteristics
What is the formula for calculating arterial O2 content (CaO2) as described in the text?
(1.34 × SaO2 × Hb) + 0.0031 × PaO2
What is the normal concentration range of sulfhemoglobin (SHb) under normal circumstances in adult blood?
Less than 1%
Which components are highlighted as the major determinants of O2 content in the blood according to the text?
SaO2 and Hb concentration
Functional O2 saturation (SaO2) refers to which concept as mentioned in the text?
amount of O2Hb as a fraction of the total amount of O2Hb and deO2Hb
What is the O2 binding capacity of Hb as presented in the text?
1.34 mL/g
fractional saturation O2 saturation (SaO2) refers to which concept as mentioned in the text?
amount of O2Hb as a fraction of the total amount of Hb
Which of the following Hb species is expected to have the lowest concentration under normal circumstances in adult blood?
Sulfhemoglobin
What is the typical concentration range of carboxyhemoglobin (COHb) in adult blood under normal circumstances?
1%-3%
Which type of Hb has the highest expected concentration under normal circumstances in adult blood?
Oxygenated Hb
What is the primary function of methemoglobin (MetHb) in the blood?
NO transport
Under normal circumstances, which Hb species is expected to have a concentration closest to that of sulfhemoglobin (SHb) in adult blood?
Methemoglobin
How does a high SaO2 differ in its ability to discriminate between normoxic and hyperoxic conditions?
It cannot differentiate between normoxic and hyperoxic conditions
How do increase in temperature, PaCO2, and 2,3-DPG concentration affect the O2Hb dissociation curve?
They shift the curve to the right
Why is it difficult to determine the partial pressure of oxygen at the higher range of oxygen saturations?
Because of the nonlinear nature of the O2Hb dissociation curve
How can 2,3-diphosphoglycerate (2,3-DPG) concentration affect the O2Hb dissociation curve?
It can shift the curve to the right or left
Considering the O2Hb dissociation curve, what happens if there is a large numeric change in PaO2 at the flat portion of the curve?
It has minor consequences on blood O2 content
Considering the O2Hb dissociation curve, at which point approximately start the flat portion of the curve?
approximately above 70 mm Hg
which of the following can shift the curve to the right ?
Acidosis
which of the following can shift the curve to the left ?
Alkalosis
Based on the absorption spectra in the text, what is the minimum number of wavelengths of light that must be measured to determine the concentrations of all five species of Hb in a blood sample?
5
In co-oximetry, which of the following is a primary measurement conducted along with oxygen saturation (SaO2) in a blood sample?
Concentration of different Hb species
What does a co-oximeter primarily rely on to determine the concentration of different hemoglobin species in a blood sample?
Wavelength of light absorbed
In oximetry, which law is utilized to relate the transmission of light through a solution to the concentration of the solute?
Beer-Lambert Law
What is the primary goal of standard pulse oximetry?
Assessing O2 saturation
How are SaO2 estimates denoted in pulse oximetry?
SpO2
What is the ratio 'R' calculated in conventional pulse oximetry based on?
Light absorption ratios at two different wavelengths
What is the significance of using 660 nm and 940 nm wavelengths in pulse oximetry?
To maximize absorbance differences of O2Hb and deO2Hb
Why does the FDA recommend specific tolerances for SpO2 measurements?
To provide accuracy in O2 saturation measurements
What can reduce the accuracy of SaO2 estimates in pulse oximetry?
Pulsatility reduction
What is the recommended root mean square difference between measured values (SpO2) and reference values (SaO2) according to the text?
≤3.0% for transmittance, wrap and clip pulse oximeter sensors, ≤3.5% for ear clip and reflectance sensors
What is the accuracy range reported by most manufacturing literature regarding SpO2 values between 70% and 100% based on the text?
±2% to 3% SpO2
How are calibration curves for O2 saturation typically developed by manufacturers, as stated in the text?
By having volunteers breathe hypoxic gas mixtures
What is the range of SaO2 values typically created during the development of calibration curves for O2 saturation according to the text?
70% to 100%
What is the range of accuracy for SpO2 over normal conditions regarding transmittance, wrap, clip, ear clip, and reflectance sensors based on the text?
2.5% to 3.5% for transmittance, wrap and clip pulse oximeter sensors, 3.0% to 3.5% for ear clip and reflectance sensors
At which wavelength does deO2Hb have greater light absorption than O2Hb?
660 nm
Which hemoglobin species has greater light absorption at 940 nm?
O2Hb
What is the primary difference in light absorption between deO2Hb and O2Hb at 660 nm?
deO2Hb absorbs more light
In pulse oximetry, which wavelength of light is used for detecting greater absorption by O2Hb than deO2Hb?
940 nm
What is the primary difference between transmission pulse oximetry and reflectance pulse oximetry?
The placement of the emitter and detector
What has pulse oximetry been defined as by the World Federation of Societies of Anaesthesiologists and the WHO?
A mandatory intraoperative monitoring standard
What do multiwavelength pulse oximeters allow for?
Continuous noninvasive monitoring of total hemoglobin concentration and MetHb and COHb
In what clinical settings has SpHb shown reasonable bias and precision?
Surgical and ICU settings
What is the role of photodetector in a pulse oximeter?
To measure transmission of light at different wavelengths
What is a limitation of SpHb mentioned in the text?
It lacks precision at low oxygen levels.
Why have noninvasive COHb measurements not replaced laboratory measurements?
They are unreliable for COHb measurements below 87% SaO2.
What is the advantage of pulse oximetry-based MetHb measurements with a newer device under hypoxic conditions?
They can detect MetHb accurately even in hypoxic situations.
Why is universal pulse oximetry recommended for screening newborns by the US Health Secretary?
To screen for critical congenital heart disease.
What percentage of critical congenital heart disease lesions can be identified when using a clinical algorithm based on SpO2 levels and routine screening?
75%
What did the modality combination of SpO2 levels and newborn physical examination screening lead to?
A total of 75% sensitivity in suspected cases.
What is the historical term used to refer to the pulsatile component of light absorption by tissue in pulse oximetry?
AC ("alternating current")
Which term refers to the nonpulsatile component of light absorption by tissues in pulse oximetry?
DC ("direct current")
What is the challenge in obtaining arterial O2 saturation in vivo when compared with in vitro oximetry?
Avoiding tissue light absorption
How do changes in blood volume affect the photoplethysmographic trace?
Changes the rhythm of the trace
What factor affects the plethysmographic trace during anesthesia according to the text?
The distensibility of the vessel wall
What variable has been shown to predict fluid responsiveness in mechanically ventilated patients based on the text?
Plethysmographic waveform amplitude variation
What index incorporated into a pulse oximeter quantifies amplitude variation during a respiratory cycle?
Pleth Variability Index (PVI)
What condition compromises the accuracy of photoplethysmography for predicting fluid responsiveness?
Presence of cardiac arrhythmias
In which patients' group has photoplethysmography been shown to have greater reliability for fluid responsiveness?
Mechanically ventilated patients
In which patients' group has photoplethysmography been shown to have greater reliability for fluid responsiveness?
better for 500 mL fluid challenges
Goal-directed fluid management based on PVI has been shown to improve outcomes in ? major abdominal surgery.
major abdominal surgery.
What can significantly affect the accuracy of SpO2 measurements?
Low SaO2
What condition can prevent the detection of hyperoxia with SpO2?
High SaO2
What is important for correct interpretation of SaO2 and PaO2 according to the text?
Knowledge of the individual Hb dissociation curve
Pulse oximetry does not provide information about which critical parameter?
tissue oxygenation
Which of the following can lead to inaccuracies in pulse oximeter readings?
Presence of intravascular dyes
What does evidence suggest about the use of pulse oximetry in patient outcomes?
Reduces the incidence of hypoxemia
What is the effect of systematic errors in SpO2 as SaO2 falls below 90%?
They tend to increase
How does the presence of other Hb variants affect the accuracy of SpO2 measurement?
It significantly affects accuracy
At SaO2 levels under 70%, what bias can be observed in the SpO2 value based on the pulse oximeter manufacturer?
positive or negative bias
What level of SaO2 indicates limited accuracy for pulse oximeters based on experimental calibration data?
Below 70%
what is the effect of motion artifact on SpO2 ?
Decreased saturation levels
At what systolic blood pressure level may erroneous SpO2 reductions be observed?
Below 80 mm Hg
What could lead to inaccuracy of SpO2 values With continued clinical use?
Degradation of LEDs in the probe
What would be the expected SpO2 range in a patient with methemoglobinemia?
80-85%
How does the presence of severe cases of sulfhemoglobinemia affect SpO2 readings based on the text?
Results in a SpO2 value of 85%
In a patient with carbon monoxide poisoning, how is SpO2 affected according to the information provided?
SpO2 will be falsely elevated
Which hemoglobin species has the highest light absorption at 660 nm?
Sulfhemoglobin (SHb)
Why may additional clinical laboratory testing be necessary for patients suspected of having sulfhemoglobinemia?
Most co-oximeters cannot detect SHb
What can cause venous O2Hb saturation to be detected by the pulse oximeter, leading to a reduction in the measured arterial SpO2?
Severe tricuspid regurgitation
What does the absorption of light at 660 nm by COHb result in when compared to O2Hb?
Similar absorption
What is a factor that may result in pulse oximeter errors due to venous pulsations despite the lack of hypoperfusion?
Adhesive finger probe placement on healthy skin
What can cause an underestimation of arterial O2 saturation in anemic patients ?
Presence of hypoxia
Which type of Hb variants has a reduced affinity for O2 and leads to appropriate changes in SaO2 and SpO2 readings?
Hb Canabiere
What effect does the administration of methylene blue have on SpO2 readings?
Transient decrease to 65%
In patients with sickle cell disease, what physiological change in Hb occurs during hypoxia?
Low O2 affinity
Which variant of Hb has altered absorption spectra, resulting in low SpO2 readings with normal SaO2?
Hb Bonn
When considering pulse oximetry readings in sickle cell disease patients, what can result in inaccurately high SpO2 values?
Elevated fetal Hb
Which nail polish colors can have the greatest effect on SpO2 readings?
Black, purple, and dark blue
What does increased skin pigmentation lead to in terms of SpO2 estimates?
Overestimation of SaO2
In the presence of severe hyperbilirubinemia, what may result in more accurate SpO2 measurements?
Falsely low fraction of oxygenated hemoglobin due to MetHb and COHb increase
How might the placement of the probe interfere with SpO2 readings when using pulse oximetry?
Allow direct detection of LED light
How does the accuracy of SpO2 readings vary in patients with continuous flow ventricular assist devices?
No SpO2 measurements possible
Test your knowledge on the processes of respiration and respiratory monitoring. Learn about the transport of gases in the body and the exchange of respiratory gases with the environment.
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