Flashcards in Measurement and monitoring Deck (195)
Loading flashcards...
1
In pulse oximetry
the SpO2 is determined by the absorbance of light wavelengths 660nm and 940nm
True
2
In pulse oximetry
Methaemaglobinaemia causes the SpO2 to approach 85%
True
3
In pulse oximetry
Fetal haemaglobin gives an inaccurately high reading of saturation
False
4
In pulse oximetry
oxyhaemoglobin absorbs better at the longer wavelength
True
5
In pulse oximetry
The pulse oximeter is less accurate at low rather than high saturations
True
6
In pulse oximetry
The arterial a.c (pulsatile) component of the signal is approximately 20% of the total absorption
False
7
In pulse oximetry
functional saturation is defined as the ratio of oxyhaemoglobin to oxyhaemoglobin plus reduced haemoglobin
True
8
In pulse oximetry
beers law relates the intensity of transmitted light to the path length
False
9
In pulse oximetry
infrared light is only absorbed by small molecules with symmetric bonds
False
10
In pulse oximetry
motion artifacts produces a high a.c to d.c signal ratio
True
11
Causes of inaccuracies on pulse oximetry include
methaemoglobinaemia
True
12
Causes of inaccuracies on pulse oximetry include
fetal haemoglobin
False
13
Causes of inaccuracies on pulse oximetry include
hypothermia
True
14
Causes of inaccuracies on pulse oximetry include
blue nail polish
True
15
Causes of inaccuracies on pulse oximetry include
extraneous light
True
16
Concerning the measurement of oxygen
A clark electrode requires a polarising voltage
True
17
Concerning the measurement of oxygen
fuel cells can be affected by the presence of nitrous oxide
True
18
Concerning the measurement of oxygen
paramagnetic analyser has a slower response time than a clark electrode
False
19
Concerning the measurement of oxygen
A polarographic technique is used in normal blood gas analysers
True
20
Concerning the measurement of oxygen
oxygen saturation is directly measured using co-oximeter
False
21
The following are directly measured in a standard blood gas analyser
pH
False
22
The following are directly measured in a standard blood gas analyser
bicarbonate
False
23
The following are directly measured in a standard blood gas analyser
oxygen tension
True
24
The following are directly measured in a standard blood gas analyser
partial pressure of CO2
False
25
The following are directly measured in a standard blood gas analyser
oxygen saturation
False
26
Arterial blood gas samples
storage at room temp causes a rise in pH
False
27
Arterial blood gas samples
a hypothermic patient will have inaccurately high pO2 if temperature-correction is not employed
True
28
Arterial blood gas samples
Air bubbles in the sample may lead to a fall in the pO2
True
29
Arterial blood gas samples
excessive heparin will cause an inaccurately high pH
False
30
Arterial blood gas samples
storage at room temp causes a fall in pO2
True
31
The oxygen electrode in a blood gas analyser
incorporates on a lead anode
False
32
The oxygen electrode in a blood gas analyser
the cathode is usually platinum
True
33
The oxygen electrode in a blood gas analyser
potassium hydroxide is the usual electrolyte in the electrode
False
34
The oxygen electrode in a blood gas analyser
current flow depends on oxygen tension at the cathode
True
35
The oxygen electrode in a blood gas analyser
is of the fuel cell type
False
36
The fuel cell
contains a lead anode
true
37
The fuel cell
has a faster response time than a polargraphic electrode
False
38
The fuel cell
is not affected by temperature
False
39
The fuel cell
nitrous oxide in the gas mixture reacts with the anode to produce nitrogen
True
40
The fuel cell
is used to measure oxygen tensionin a blood gas analyser
False
41
Concerning the clark PO2 electrode
is composed of a platinum cathode and a gold anode
False
42
Concerning the clark PO2 electrode
an oxygen consuming electrochemical reaction takes place at the anode
False
43
Concerning the clark PO2 electrode
it can be used to measure oxygen partial pressure in gases and liquids
True
44
Concerning the clark PO2 electrode
it requires a voltage of 0.6V to be applied between its electrode
True
45
Concerning the clark PO2 electrode
it is sensitive to changes in temperature
True
46
The Severinghaus CO2 electrode
incorporates KCL and NaHCO3 in the electrolyte solution
True
47
The Severinghaus CO2 electrode
directly measures the Pa CO2
False
48
The Severinghaus CO2 electrode
incorporates hydrogen ion sensitive glass
True
49
The Severinghaus CO2 electrode
incorporates a platinum wire cathode
False
50
The Severinghaus CO2 electrode
is affected by temperature
True
51
Recognised methods of measuring anaesthetic vapour concentration include
Raman scattering
True
52
Recognised methods of measuring anaesthetic vapour concentration include
Paramagnetism
False
53
Recognised methods of measuring anaesthetic vapour concentration include
ultraviolet absorption
True
54
Recognised methods of measuring anaesthetic vapour concentration include
mass spectrometry
True
55
Recognised methods of measuring anaesthetic vapour concentration include
photoacoustic spectrophotometry
True
56
The following can be used to measure carbon dioxide in expired gases (capnography)
clark polargraphic electrode
False
57
The following can be used to measure carbon dioxide in expired gases (capnography)
paramagnetic analyser
False
58
The following can be used to measure carbon dioxide in expired gases (capnography)
infrared absorption spectrometry
True
59
The following can be used to measure carbon dioxide in expired gases (capnography)
mass spectrometry
True
60
The following can be used to measure carbon dioxide in expired gases (capnography)
Ramen analyser
True
61
The following have infrared absorption spectra which overlap with that of carbon dioxide
water vapour
True
62
The following have infrared absorption spectra which overlap with that of carbon dioxide
sevoflurane
True
63
The following have infrared absorption spectra which overlap with that of carbon dioxide
nitrous oxide
True
64
The following have infrared absorption spectra which overlap with that of carbon dioxide
nitrogen
False
65
The following have infrared absorption spectra which overlap with that of carbon dioxide
helium
False
66
Concerning the measurement of expired CO2 using the infrared absorption technique
the wavelength of infrared light used is 4.3 micrometers
True
67
Concerning the measurement of expired CO2 using the infrared absorption technique
the absorption of infrared light by CO2 is based on the beer-lambert law
True
68
Concerning the measurement of expired CO2 using the infrared absorption technique
the windows on the sample chamber are made of lead crystal glass
False
69
Concerning the measurement of expired CO2 using the infrared absorption technique
nitrous oxide interferes with infrared absorption by CO2
True
70
Concerning the measurement of expired CO2 using the infrared absorption technique
O2 interferes with infrared absorption by CO2
True
71
Concerning spectrophotometric absorption spectra or reduced and oxygenated haemoglobin
at the isobestic point the absorption coefficient is the same
True
72
Concerning spectrophotometric absorption spectra or reduced and oxygenated haemoglobin
the isobestic point occurs at a wavelength around 650nm
False
73
Concerning spectrophotometric absorption spectra or reduced and oxygenated haemoglobin
the amount of oxygenated haemoglobin is directly proportional to the shift in the isobestic point
False
74
Concerning spectrophotometric absorption spectra or reduced and oxygenated haemoglobin
the maximum difference in the absorption of the two forms of haemoglobin occurs at a wavelength around 940nm
False
75
Concerning spectrophotometric absorption spectra or reduced and oxygenated haemoglobin
The pulse oximeter usess the difference between the absorption spectra of the two forms of Hb to quantify their relative concentrations
True
76
Refractometers:
are capable of measuring vapour concentration in gas mixture
True
77
Refractometers:
require calibration
True
78
Refractometers:
directly measure the vapour concentration
False
79
Refractometers:
are not influenced by water vapour
False
80
Refractometers:
are used to calibrate vapourisers
True
81
Blood-gas analysis:
The base excess is the amount of strong acid required to return the pH of 1 litre of blood to 7.40 at a PCO2 of 5.3 kPa and 37C
True
82
Blood-gas analysis:
too much heparinised saline tends to cause a falsely low reading of the PCO2
True
83
Blood-gas analysis:
Too much heparing tends to cause a falsely lo reading of potassium concentration
False
84
Blood-gas analysis:
A clark electrode requires a battery
True
85
Blood-gas analysis:
prolonged storage at 4C may lead to a falsely low vlue for PO2
True
86
The following statements are correct
visible light has a wavelength between 400 and 700 nm
True
87
The following statements are correct
CO2 has a peak absorption at 4.3 micrometers
True
88
The following statements are correct
3.3 micrometers is the commen absorption peak for the volatile anaesthetic agents
True
89
The following statements are correct
methane interferes with gas analysis in the 9-11 micrometer band
False
90
The following statements are correct
Collision broadening alters the wavelength at which infrared absorption by CO2 takes place
True
91
Concerning mass spectrometry
The analysing hamber is operated at atmospheric pressure
False
92
Concerning mass spectrometry
The ions are accelerated by an anode plate
False
93
Concerning mass spectrometry
In a quadrupole mass spectrometer there are two large electromagnets
False
94
Concerning mass spectrometry
The sample from a mass spectrometer can be returned to a circle system to allow low flow anaesthesia
False
95
Concerning mass spectrometry
mass spectrometry is less accurate than infrared absorption
False
96
The following statements are correct
fuel cells are suitable for breath to breath analysis of oxygen concentration
False
97
The following statements are correct
Unpaired elctrons are responsible for oxygens paramagnetic property
True
98
The following statements are correct
damping coefficient is inversely proportional to the amplitude ratio in invasive arterial pressure measurement
True
99
The following statements are correct
The natural frequency of a mass-string dynamic oscillator is directly proportional to its mass
False
100
The following statements are correct
fourier tranformation is a mathematical operations that deconstructs a complex signal into its constituent frequencies
True
101
The following physical properties may be used in the measurement of pressure:
Change or electrical resistance in a wire
True
102
The following physical properties may be used in the measurement of pressure:
Variable inductance
True
103
The following physical properties may be used in the measurement of pressure:
Piezoelectric effect
False
104
The following physical properties may be used in the measurement of pressure:
Change in flow through a narrow tube
False
105
The following physical properties may be used in the measurement of pressure:
Torricellian vacuum
True
106
Non-invasive measurement of blood pressure:
Tends to give lower systolic pressure than direct means
True
107
Non-invasive measurement of blood pressure:
the diastolic pressure is recorded as the pressure at which the first muffling of the sound occurs
False
108
Non-invasive measurement of blood pressure:
The mean arterial pressure is the point of maximum oscillation in the cuff pressure
False
109
Non-invasive measurement of blood pressure:
requires a cuff that is wider than the diameter of the arm
True
110
Non-invasive measurement of blood pressure:
Tends to give a lower diastolic pressure than direct means
False
111
Transducers commonly used in physiological monitoring include:
Strain gauge
True
112
Transducers commonly used in physiological monitoring include:
pH meter
True
113
Transducers commonly used in physiological monitoring include:
Ear Oximeter
True
114
Transducers commonly used in physiological monitoring include:
ECG electrode
False
115
Transducers commonly used in physiological monitoring include:
Galvanic fuel cell
True
116
Considering direct intra-arterial blood pressure measurement:
in an underdamped transducer system (D<0.5) significant overshoot and subsequent oscillation occurs
True
117
Considering direct intra-arterial blood pressure measurement:
in an optimally damped system (D=0.64) overshoot is limited to 6-7% of the initial pressure change and no oscillation will occur
True
118
Considering direct intra-arterial blood pressure measurement:
In a critically damped system (D=1.0) the change in mean pressure will be measured accurately with no overshoot
True
119
Considering direct intra-arterial blood pressure measurement:
In an overdamped system (>1.0) the response is progressively slower
True
120
Considering direct intra-arterial blood pressure measurement:
A fast fluch test can be used to assess the level of damping
True
121
Distortion of the trace seen in direct arterial monitoring is increased by:
Bubbles
True
122
Considering direct intra-arterial blood pressure measurement:
Connections in the tubing
True
123
Considering direct intra-arterial blood pressure measurement:
Shortening the tubing
False
124
Considering direct intra-arterial blood pressure measurement:
increasing the diameter of the tubing
False
125
Considering direct intra-arterial blood pressure measurement:
clots in the cannula
True
126
Measuring cardiac output by the thermodilution method:
Injecting less than the required volume of injectate leads to an over-estimation of the cardiac output
True
127
Measuring cardiac output by the thermodilution method:
injection should be performed over about 10 sec
False
128
Measuring cardiac output by the thermodilution method:
Looping of the catheter in the right ventricle may cause inaccuracies in the measurement
True
129
Measuring cardiac output by the thermodilution method:
The cardiac output is assessed by measuring the area under the temperature change curve
True
130
Measuring cardiac output by the thermodilution method:
Cardiac output measurements will be unchanged by wedging of the pulmonary artery catheter
False
131
The following may be employed in the measurement of cardiac output:
Lithium Dilution
True
132
The following may be employed in the measurement of cardiac output:
thermal conductivity
False
133
The following may be employed in the measurement of cardiac output:
Indocyanine green indicator dilution
True
134
The following may be employed in the measurement of cardiac output:
Impedance cardiography
True
135
The following may be employed in the measurement of cardiac output:
Aortic Doppler Ultrasound
True
136
Using Fick principle to measure cardiac output, with oxygen as the indicator gas, it it essential to know the:
oxygen uptake
True
137
Using Fick principle to measure cardiac output, with oxygen as the indicator gas, it it essential to know the:
arterial oxygen content
True
138
Using Fick principle to measure cardiac output, with oxygen as the indicator gas, it it essential to know the:
respiratory quotient
True
139
Using Fick principle to measure cardiac output, with oxygen as the indicator gas, it it essential to know the:
mixed venous oxygen content
True
140
Using Fick principle to measure cardiac output, with oxygen as the indicator gas, it it essential to know the:
arterial carbon dioxide content
False
141
Bispectral index:
Is measured in Hertz
False
142
Bispectral index:
is used as a measure of the depth of anaesthesia
True
143
Bispectral index:
is not affected by natural sleep
False
144
Bispectral index:
preoperative opioids decrease the value
False
145
Bispectral index:
is a reliable monitor to predict recall under anaesthesia
False
146
With reference to the principles of oesophageal doppler cardiac output monitoring:
The volume of blood flowing in the descending aorta is measured
False
147
With reference to the principles of oesophageal doppler cardiac output monitoring:
The angle of insonation between the ultrasound waves and the blood stream must be known
True
148
With reference to the principles of oesophageal doppler cardiac output monitoring:
The cross sectional area of the aorta must be known
True
149
With reference to the principles of oesophageal doppler cardiac output monitoring:
The probe should be positioned so the tip faces anteriorly
False
150
With reference to the principles of oesophageal doppler cardiac output monitoring:
The probe measures total cardiac output
False
151
Regarding depth of anaesthesia monitoring:
Auditory evoked potentials are a composite waveform
True
152
Regarding depth of anaesthesia monitoring:
Entropy is calculated from the amount of disorder in the power spectrum of the EEG
True
153
Regarding depth of anaesthesia monitoring:
Bispectral index is agent specific
False
154
Regarding depth of anaesthesia monitoring:
Entropy is reported using a dimensionless scale
True
155
Regarding depth of anaesthesia monitoring:
Auditory evoked potentials exhibit minimal hysteresis
True
156
The following are true of nerve stimulators:
The applied electrical potential can be as high as 150V
True
157
The following are true of nerve stimulators:
The apparatus uses a square wave electrical signal
True
158
The following are true of nerve stimulators:
The pulse current should be between 0.5 and 5.0mA when the skin electrodes are used
False
159
The following are true of nerve stimulators:
At a constant voltage, an increase in resistance is associated with an increase in current flow
False
160
The following are true of nerve stimulators:
Stimulation at a constant current is preferable to stimulation at a constant volatage
True
161
When using a train of four to monitor a non-depolarising block:
The stimulator should deliver four supramaximal stimuli at 4Hz
False
162
When using a train of four to monitor a non-depolarising block:
The fourth twitch (T4) will be smaller than the first twitch
True
163
When using a train of four to monitor a non-depolarising block:
Post-tetanic facilitiation is due to accumulation of acetylcholine in the synaptic cleft
True
164
When using a train of four to monitor a non-depolarising block:
The response to muscle relaxants of the facial muscles is similar to that of the diaphragm
True
165
When using a train of four to monitor a non-depolarising block:
Presence of all four twitches indicates a patient who is adequately reversed for extubation
False
166
The following statements are true of double burst stimulation neuromuscular monitoring:
It consists of two burst of tetanus at 100Hz
False
167
The following statements are true of double burst stimulation neuromuscular monitoring:
each impulse is separated by 20sec
False
168
The following statements are true of double burst stimulation neuromuscular monitoring:
The 2 bursts are separated by 750msec
True
169
The following statements are true of double burst stimulation neuromuscular monitoring:
The DBS ration has similar properties to the TOF ratio
True
170
The following statements are true of double burst stimulation neuromuscular monitoring:
DBS is accurate at detecting deep neuromuscular block
False
171
Concerning temperature measurement:
A mercury thermometer is suitable for measuring temperatues from -30C to at least 200C
True
172
Concerning temperature measurement:
A resistance thermometer is normally used in a wheatstone bridge configuration
True
173
Concerning temperature measurement:
Thermistors are metal oxide superconductors
False
174
Concerning temperature measurement:
Thermistors are resistant to heat sterilisation
False
175
Concerning temperature measurement:
A thermocouple relies on the seebeck effect
True
176
The fleisch Pneumotachograph:
is a constant pressure flowmeter
False
177
The fleisch Pneumotachograph:
is not useful for breath-to-breath measurements
False
178
The fleisch Pneumotachograph:
is designed to measure laminar flow
True
179
The fleisch Pneumotachograph:
uses a pressure transducer to measure flow
True
180
The fleisch Pneumotachograph:
becomes inaccurate because condensation is common
False
181
Concerning rotameters:
It consists of a vertical tube with even diameter
False
182
Concerning rotameters:
The pressure drop across the bobbin increases with increasing flow
False
183
Concerning rotameters:
At low flows, the viscosity of the gas becomes important
True
184
Concerning rotameters:
At high flows the density of the gas becomes important
True
185
Concerning rotameters:
In a hyperbaric chamber, a flowmeter will deliver less gas than the setting indicate
True
186
Concerning rotameters:
Are a form of variable orifice flowmeter
True
187
Concerning rotameters:
Are susceptible to static electricty
True
188
Concerning rotameters:
Should be accurate to within 0.2%
False
189
Concerning rotameters:
Consists of a bobbin in a parallel-sided tube
False
190
Concerning rotameters:
The bobbin has vanes to help it to spin freely
True
191
Regarding humidity:
Absolute humidity = volume of water vapour in unit volume of air at specified pressure & temp
False
192
Regarding humidity:
Relative humidty = partial pressure of water vapour divided by the SVP of water at specified temp
True
193
Regarding humidity:
Absolute humidity can be measured by a Regnault's hygrometer
False
194
Regarding humidity:
The Regnault's hygrometer relies on evaporation
True
195
