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40 Cards in this Set
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CM01 [ackmo] As ambient temperature increases, heat loss increases by:
A. Radiation B. Convection C. Conduction D. Evaporation E. Vasodilatation F. None of the above |
CM01 [ack] As ambient temperature increases, heat loss increases by:
A. Radiation B. Convection C. Conduction D. Evaporation – Most likely, but depends on relative humidity E. None of the above (Also remembered as: “In hot climates, most heat is lost by:”) |
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CM02 [af] All are ways of measuring O2 in a gas mixture EXCEPT:
A. Paramagnetic analyser B. Clark electrode C. Infrared absorption D. Mass spectroscopy |
ANSWER C
Infrared is only absorbed when there is two dissimilar atoms. Therefore it cannot be used for O2 analysis |
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CM03 [aefhk] With regard to oxygen:
A. The only gas that can reignite a glowing splint B. Causes pulmonary (?oxygen toxicity/?hypertension) at less than 100 kPa C. Some CNS toxicity occurs at 100 kPa (? or: < 100kPa) D. Medical grade is 95% pure E. Produced commercially by hydrolysis of water F. May result in the reduction of alveolar lung volume if given at an FIO2 of 1.0 |
CM03 [aefhk] With regard to oxygen:
A. The only gas that can reignite a glowing splint – No, Nitrous oxide can do the same (it supports combustion) B. Causes pulmonary (?oxygen toxicity/?hypertension) at less than 100 kPa – No C. Some CNS toxicity occurs at 100 kPa (? or: < 100kPa) – No D. Medical grade is 95% pure – No, medical grade is 99.5% pure (according to BOC gases) E. Produced commercially by hydrolysis of water – No, it is produced by liquefaction of atmospheric air and separation of the oxygen by fractionation. Very little is produced by hydrolysis of water F. May result in the reduction of alveolar lung volume if given at an FIO2 of 1.0 – Yes, absorption atelectasis |
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CM04 [cdhlr] A naked 70kg man in a theatre at 20C will lose most heat by:
A. Conduction to air molecules next to the patient B. Conduction to the table C. Radiation to OT equipment and walls D. Convection E. None of the above |
CM04 [cdhl] A naked 70kg man in a theatre at 20C will lose most heat by:
A. Conduction to air molecules next to the patient – Probably, given the flow rates of some of the airconditioners…. B. Conduction to the table C. Radiation to OT equipment and walls – Most correct D. Convection E. None of the above |
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CM05 [ci] A pulse oximetry reading is underestimated by:
A. Methaemoglobinaemia B. Carboxyhaemoglobinaemia C. Foetal haemoglobin D. Sickle cell anaemia Also remembered as: |
ANSWER A
A. Methaemoglobinaemia – Correct (reading approaches 85% as the Red & Infrared absorption levels are the same for MetHb – hence the R value approaches 1) |
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[i] Normal two-wavelength pulse oximetry will underestimate oxygen saturation in the presence of:
A. Methaemoglobinaemia B. Carboxyhaemoglobinaemia C. Hyperbilirubinaemia D. Haemoglobin F E. Haemoglobin S |
[i] Normal two-wavelength pulse oximetry will underestimate oxygen saturation in the presence of:
A. Methaemoglobinaemia – Correct (reading approaches 85% as the Red & Infrared absorption levels are the same for MetHb – hence the R value approaches 1) B. Carboxyhaemoglobinaemia C. Hyperbilirubinaemia D. Haemoglobin F E. Haemoglobin S |
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CM06 [c] With respect to one mole each of CO2 and N2O, which is untrue?
A. Same weight B. Same density C. Same viscosity D. Same volume at STP (Note: Both have MW of 44, so one mole of each will weigh 44G) |
CM06 [c] With respect to one mole each of CO2 and N2O, which is untrue?
A. Same weight - Correct B. Same density – Almost correct (see D) C. Same viscosity - No D. Same volume at STP – This is almost correct… (the universal gas equation – but this is for an IDEAL gas) (Note: Both have MW of 44, so one mole of each will weigh 44G) |
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CM07 [dh] Remains constant with adiabatic expansion of a gas:
A. Density B. Pressure C. Volume D. Temperature E. None of the above |
CM07 [dh] Remains constant with adiabatic expansion of a gas (which is not possible in reality):
A. Density – No, it will decrease B. Pressure – No, it decreases C. Volume – No. This is given in the question – adiabatic EXPANSION – although it can technically be done with vacuums without a volume change D. Temperature – No, it decreases (but HEAT is constant) E. None of the above – Correct • When a gas expands, it does work (opposite of work done on it) -W so the work done on it is negative and therefore the internal energy decreases therefore temperature decreases. • When a gas expands adiabatically, no heat is supplied to it so energy to do work is taken from its internal energy. Ie. HEAT is the same • A perfectly adiabatic expansion is not actually possible. But a change is almost adiabatic when the gas is in a container which has bad conducting walls. Example of an adiabatic expansion is the escape of air when a tyre bursts. |
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CM08 [dh] At an altitude of 5,500m (barometric pressure 380mmHg), assuming a normal
pCO2 of 40mmHg, pAO2 will be: A. 20mmHg B. 30mmHg C. 40mmHg D. 50mmHg E. 60mmHg |
CM08 [dh] At an altitude of 5,500m (barometric pressure 380mmHg), assuming a normal
pCO2 of 40mmHg, pAO2 will be: A. 20mmHg – Correct, and arterial pO2 will be even lower… B. 30mmHg C. 40mmHg D. 50mmHg E. 60mmHg (see also RE29) PAO2= (FIO2 * (Pb – Pwater)) – PCO2 / 0.8 = (0.21*(380-47) – (40 / 0.8) = 69.93 – 50 = 19.93mmHg |
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CM09 [d] According to the Hagen-Pouseille Law:
A. Flow varies inversely with resistance B. Viscosity varies inversely with length C. ? |
CM09 [d] According to the Hagen-Pouseille Law:
A. Flow varies inversely with resistance – Correct, provided that the flow is laminar B. Viscosity varies inversely with length C. ? |
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CM10 [d] Turbulence is more likely with:
A. Small tube diameter B. High density fluid C. ?Increased/decreased length of tube D. ?Increased/decreased viscosity E. None of the above |
CM10 [d] Turbulence is more likely with:
A. Small tube diameter – No, less likely B. High density fluid - Yes C. ?Increased/decreased length of tube – No, length of the tube is irrelevent D. ?Increased/decreased viscosity – If you decrease viscosity, turbulence is more likely E. None of the above R=ρdv/η |
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CM11 [dfh] Pneumotachograph:
A. Can be used to measure peak airflow B. Measures velocity and not flow (??accurate in turbulent & laminar flow) C. Is accurate at all flow rates D. Variable orifice flowmeter E. Can be used to measure volume F. Unaffected by temperature |
CM11 [dfh] Pneumotachograph
A. Can be used to measure peak airflow – Correct, if designed for those flow rates… B. Measures velocity and not flow (??accurate in turbulent & laminar flow) C. Is accurate at all flow rates D. Variable orifice flowmeter E. Can be used to measure volume – Correct, need to integrate flow over time… ? (A) more correct F. Unaffected by temperature |
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CM12 [fhimn] Cardiac output measurement is most accurate with which method?
A. Direct Fick B. Radionuclide angiocardiography C. Gated pooling D. LV angiogram E. Transthoracic echocardiography F. Thermodilution |
Answer A, as confirmed by uncle wiki.
CM12 [fhi] Cardiac output measurement is most accurate with which method? A. Direct Fick – Probably… B. Radionuclide angiocardiography – Who knows… C. Gated pooling – Could be… D. LV angiogram – No… obviouisly E. Transthoracic echocardiography – No, there are much more accurate methods F. Thermodilution |
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CM13 [f] Impedance:
A. Increases as the frequency of an AC current increases across a capacitor B. Decreases as the frequency of an AC current increases across an inductor C. Is constant across a resistor D. All of the above E. None of the above |
ANSWER C
CM13 [f] Impedance: A. Increases as the frequency of an AC current increases across a capacitor – No, decreases B. Decreases as the frequency of an AC current increases across an inductor – No, increases C. Is constant across a resistor – Correct D. All of the above E. None of the above |
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CM13b This question was also remembered as:
As the frequency of an alternating current increases: A. Impedance increases in a resistor B. Impedance increases in a capacitor C. Impedance increases in an inductor D. All of the above E. None of the above |
CM13b Also remembered as:
As the frequency of an alternating current increases: A. Impedance increases in a resistor – No, no change B. Impedance increases in a capacitor – No C. Impedance increases in an inductor - Correct D. All of the above E. None of the above |
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CM13c [g] Impedance as AC frequency increases:
A. In a resistor - no change B. In a capacitance - increases C. In an inductor - decreases D. All of the above E. None of the above |
CM13c [g] Impedance as AC frequency increases:
A. In a resistor - no change - Correct B. In a capacitance - increases C. In an inductor - decreases D. All of the above E. None of the above |
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CM14 [f] Oxygen manufacture:
A. Hydrolysis of water B. ?? 95% pure C. ? |
CM14 [f] Oxygen manufacture:
A. Hydrolysis of water – Not for medical use but it can be! B. ?? 95% pure – No C. ? By fractional distillation of air… and is 99.5% pure according to BOC gases (www.boc.com.au) |
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CM15 [f] According to Fick’s law, diffusion is related:
A. Directly to thickness B. Inversely to concentration gradient C. Inversely to surface area D. Inversely thickness |
ANSWER D
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CM16 [gi] Stroke volume is most accurately measured with:
A. Thermodilution B. Thoracic bioimpedance C. Doppler D. Electromagneto-. . ? . . E. Echocardiography |
CM16 [gi] Stroke volume is most accurately measured with:
A. Thermodilution – Possibly, but doesn’t take into account stroke volume that may not exit through the aortic valve… B. Thoracic bioimpedance C. Doppler D. Electromagneto-. . ? . . E. Echocardiography – Probably, and loss of volume through incompetent mitral valves may be evident…? |
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CM17 [gk] When indocyanine green is used to measure hepatic blood flow, levels are taken from:
A. Hepatic vein & portal vein B. Hepatic artery & portal vein C. Radial artery & hepatic vein D. Hepatic artery & hepatic vein E. Radial artery & right atrium |
CM17 [gk] When indocyanine green is used to measure hepatic blood flow, levels are taken from:
A. Hepatic vein & portal vein B. Hepatic artery & portal vein C. Radial artery & ?hepatic vein – Most correct D. Hepatic artery & hepatic vein E. Radial artery & right atrium |
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CM18 [fj] Specific heat capacity of which of the following is the highest?
A. Stored whole blood B. Red blood cells C. Muscle tissue D. Water E. Air |
ANSWER D
A. Stored whole blood – No, 85% of (D) (3.5 kJ/kg/K) B. Red blood cells – No, 85% of (D) (3.5 kJ/kg/K) C. Muscle tissue – No, 85% of (D) (3.5 kJ/kg/K) D. Water – Correct (4.2 kJ/kg/K) E. Air |
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July 00 version: The specific heat capacity is greatest in:
A. Packed red blood cells B. Whole blood C. Water D. Saline |
ANSWER C
A. Packed red blood cells – No, 85% of (D) (3.5 kJ/kg/K) B. Whole blood – No, 85% of (D) (3.5 kJ/kg/K) C. Water – Correct (4.2 kJ/kg/K) D. Saline? |
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CM20 [hk] Solubility of gases in blood (?at 37C):
A. O2 > CO2 > N2 B. N2O > CO2 C. CO2 > N2 > O2 D. . . (etc) E. N20 < 02) |
CM20 [hk] Solubility of gases in blood (?at 37C):
A. O2 > CO2 > N2 – No B. N2O > CO2 – No C. CO2 > N2 > O2 – No D. . . (etc) E. N20 < O2) – No |
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Apr 2001 version: Regarding the solubility of gases in PLASMA
A Nitrous oxide is less soluble than carbon dioxide B Carbon dioxide is less soluble than oxygen C Carbon dioxide is less soluble than Nitrogen D Nitrous oxide is less soluble than oxygen E Nitrous oxide is less soluble than Nitrogen F Oxygen is less soluble than Nitrogen |
Apr 2001 version: Regarding the solubility of gases in PLASMA
A Nitrous oxide is less soluble than carbon dioxide – Correct (see below) B Carbon dioxide is less soluble than oxygen – No C Carbon dioxide is less soluble than Nitrogen – No D Nitrous oxide is less soluble than oxygen – No E Nitrous oxide is less soluble than Nitrogen – No F Oxygen is less soluble than Nitrogen – No Nunn 209: relative to O2 in water, CO2 (24) > N2O (16) > NO (1.7) > O2 (1) > CO (0.75) > N2 (0.5) > He (0.4) Therefore Solubility = CO2 > N2O > O2 > N2 Interestingly though λB:G = 0.03 - 0.45 - 0.003 - 0.015 (for CO2 - N2O - O2 - N2 respectively) |
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CM22 [j] In a patient with pulmonary obstruction addition of helium to the inspired mixture:
A. Density is not altered B. Flammability of mixtur is increased C. Viscosity is minimally altered D. Rotameter would not need to be recalibrated E. Decreased O2 transfer F. Solubility of oxygen is decreased |
CM22 [j] In a patient with pulmonary obstruction addition of helium to the inspired mixture:
A. Density is not altered – No, it is decreased B. Flammability of mixture is increased – No, it is either no different or decreased… (still need a FUEL source) C. Viscosity is minimally altered - Correct D. Rotameter would not need to be recalibrated – Possibly, but it would depend on where in the circuit the helium is added… E. Decreased O2 transfer – No F. Solubility of oxygen is decreased – No change |
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CM23 [j] For washout curve described by ?? y = y0 . e-k T/
A. After 2 time constants 13.5% remains B. 50% of substance remaining after 1 time constant C. After 6 times constants y = e D. After 2 half lives 90% has been removed E. After 1 half life 37% remains |
CM23 [j] For washout curve described by ?? y = y0 . e-k T/τ
A. After 2 time constants 13.5% remains – Correct B. 50% of substance remaining after 1 time constant C. After 6 times constants y = e D. After 2 half lives 90% has been removed E. After 1 half life 37% remains |
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CM24 [j] Hagen-Poiseuille relationship:
A. ?? laminar flow B. ?? turbulent flow C. ? |
CM24 [j] Hagen-Poiseuille relationship:
A. ?? laminar flow – Correct, It’s to do with laminar flow “The pressure loss caused by the laminar internal flow of a fluid through a tube is directly proportional to the flow's velocity” This is the method by which LFE (laminar flow elements) can accurately measure flow rates of a gas through a tube B. ?? turbulent flow C. ? |
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CM25 [k] Pulmonary artery catheter can be used for:
A. Direct measurement of LAP B. Applying Fick’s principle, can be used to measure cardiac output C. Valve diameter D. Diastolic dysfunction |
Answer B
Pulmonary Artery Cathether is used for monitoring/measuring: Pulmonary Artery Pressures. Mixed Venous Oxygen Saturations and Blood Gas Analysis. Temperature. Pulmonary Artery Occlusion Pressure ∝ LVEDP ∝ LVEDV. Cardiac Output by Thermodilution. |
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CM26 [l] An apparatus whereby an external voltage is applied to a silver/silver chloride anode and a platinum cathode would be best used to measure
A. Oxygen content B. Oxygen partial pressure C. Carbon dioxide content D. Carbon dioxide partial pressure E. pH |
platinum cathode would be best used to measure
A. Oxygen content B. Oxygen partial pressure – Yes, this is a Clarke electrode (the anode electrolyte is actually KCl… but it does produce AgCl during the reaction) C. Carbon dioxide content D. Carbon dioxide partial pressure E. pH – No, this is with a glass (Ag/AgCl) electrode & a calomel (Hg2/Hg2Cl2) electrode |
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CM27 [l] For laminar flow:
A. Decreased by increased pressure B. Influenced by viscosity C. Influenced by density D. Proprtional to length to 4th power E. ? |
CM27 [l] For laminar flow:
A. Decreased by increased pressure – No, increased B. Influenced by viscosity – Yes, increasing viscosity decreases flow rate C. Influenced by density – No, this is for turbulent flow D. Proprtional to length to 4th power – No, it’s proportional to the radius to the 4th power E. ? |
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CM28 [l] Carbon dioxide dissolved in blood follows which law?
A. Charles law B. Avogadro’s law C. Henry’s law D. Dalton’s law E. Boyles law |
CM28 [l] Carbon dioxide dissolved in blood follows which law?
A. Charles law – No, “at a constant pressure, the volume of a sample of gas is directly proportional to the temperature of the gas.” B. Avogadro’s law – No, “the volume of a gas at a given temperature and pressure, is directly proportional to the quantity of gas. Thus, V is proportional to n, the number of moles of the gas” C. Henry’s law – Yes – “at equilibrium, at a given temperature, the amount of gas dissolved in a given volume of liquid is directly proportional to the partial pressure of that gas in the gas phase (this only holds for gases that do not react chemically with the solvent).” D. Dalton’s law – No, “Each gas in a mixture of gases exerts a pressure proportionate to the percentage of the gas and independent of the presence of the other gases present” E. Boyles law – No, “This law states that the volume of a sample of gas is, at a constant temperature, inversely proportional to the pressure of that gas” |
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CM29 [l] Electroencephalogram (EEG):
A. Reticular activating system B. Limbic system C. Thalamus D. Cortex E. ? |
CM29 [l] Electroencephalogram (EEG):
A. Reticular activating system B. Limbic system C. Thalamus D. Cortex – Correct (largest ionic fluxes, and closest to detectors) E. ? |
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CM30 [nop] Which of following utilises change in electrical resistance (wording?)
A.. “something about wire” B. Strain gauge C. Katharometer D. Bourdon gauge E. Thermocouple |
ANSWER D
A.. “something about wire” B. Strain gauge - A device for determining the amount of strain (change in dimensions) when a stress is applied – it is a resistor whose resistance changes as a function of the ‘deformation’ C. Katharometer - an instrument used for the analysis of gases by measurement of thermal conductivity D. Bourdon gauge - A pressure gage consisting of a tube bent into an arc which straightens out under internal pressure actuating a pointer on a scale. E. Thermocouple - a kind of thermometer consisting of two wires of different metals that are joined at one end; a potential difference (voltage) is generated between the other two ends which changes as the temperature of the joined end is altered… |
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CM32 [q] Which combination of pulmonary artery catheter values is consistent with cardiogenic shock ?
A. High PCWP, low CI, high SVR B. Low EF, high PCWP, low MAP C. High EF, low PCWP, low MAP |
Cardiogenic shock leads to a low output state.
Consequently; the CO or CI will drop- due to low output PCWP will likely increase due to low output EF is likely to fall MAP may initially be maintained due to increased SVR SVR will increase- to try and compensate for the low output So I think the answere is A in both cases |
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CM32b [r] Features of Cardiogenic shock CO PCWP Peripheral vessels
A decrease increase v.constriction B decrease decrease v.constriction C increase increase v.dilation D decrease increase v.dilation E increase decrease v.dilation |
Cardiogenic shock leads to a low output state.
Consequently; the CO or CI will drop- due to low output PCWP will likely increase due to low output EF is likely to fall MAP may initially be maintained due to increased SVR SVR will increase- to try and compensate for the low output So I think the answere is A in both cases |
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CM33 [q] When estimating LVEDV from PCWP, all of the following are assumptions except :
A. Normal Mitral valve B. Normal LV compliance C. Normal airway pressures D. Normal LV systolic function |
ANSWER D
Measured PCWP overestimates LVEDV if there is abnormal mitral valve (MR or MS) Measured PCWP underestimates LVEDV if the LV is noncompliant Measured PCWP overestimates LVEDV if there is increased PEEP (or airway pressure) LV systolic dysfunction does not interfere with the end diastolic point in the pressure-volume loop. Clinically, LV systolic dysfunction can be an indication for the use of PA catheters for the purposes of optimising LV preload (eg for cardiac surgery). |
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CM34 [qr] The attenuation of ultrasound is NOT affected by :
A. Frequency B. Velocity C. The number of interfaces D. Wavelength E. Type of tissue |
B velocity is an intrinsic property of the tissue
A Increasing frequency increases attenuation (ie decreases penetration) but increases resolution C Some energy is reflected at each interface D Wavelength is result of frequency (ie velocity = frequency x wavelength) E Tissue can absorb or scatter sound energy variably |
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CM35 [r] Which is the derived SI unit for pressure measurement?
A. mmHg B. cmH2O C. atm D. torr E. pascal |
Answer E.
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CM36 Which of the following is NOT a base SI unit?
A. metre B. ampere C. candela D. kelvin E. Newton |
Answer E. Newton
Newton = m·kg·s^-2 and is not an SI unit but an SI derived Unit. |
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CM37 Which is true regarding the Clarke electrode?
A. Has a Ag/AgCl cathode and a platinum anode. B. Can measure pO2 in both gas and blood sample. C. Uses a 0.6 amp polarising current. D. Is accurate despite changing temperature. E. Is calibrated using a special electrical device. |
Answer B.
A: Ag/AgCl anode, Platinum Cathode B: True according to Davis et al, but Protein deposition on cathode occurs therefore plastic membrane separates blood from an electrolyte surrounding Cathode. C: 0.6 Volt Potential, current is what is measured. D: Electrode must be maintained at 37deg C E: Standardised Gas misxtures are used for calibration |
