Miscellaneous Equipment

Front 1

[May09] What is true regarding arterial pressure transducer systems
A. Underdamping overestimates systolic BP
B. Underdamping underestimates MAP
C. Compliant tubing?

Back 1

A. Underdamping overestimates systolic BP
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see also EM68 - alternative wording
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Front 2

[May09][Oct09]
What is the appropriate LMA size for an 8kg child:
A. 1
B. 1.5
C. 2
D. 2.5
E. 3

Back 2

B. 1.5
-
I always remember LMA 4 for females and 5 for males if going by RECOMMENDED weight.
5 = 70-100kg
4= 50-70kg
3 = 30-50kg
2.5 = 20-30kg
2 = 10-20kg
1.5 = 5-10kg
1 = <5kg
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Front 3

[Oct08] The Line Isolation Transformer

a. ?

b. ?

c. Provides low current to the line isolation monitor

d. Separates earth from the OT electrical supply (similar wording)

e. ?

Back 3

d. Separates earth from the OT electrical supply (similar wording)
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Front 4

EM69 ANZCA version [Apr08] [Oct08] [Aug09] [Mar 10]

The systolic blood pressure may be overestimated by the auscultatory method of blood pressure measurement if:

A. the cuff is deflated too slowly
B. the patient has severe arteriosclerosis
C. the patient's arm is very thin
D. there is severe peripheral vasoconstriction
E. too wide a cuff is used

Back 4

B. the patient has severe arteriosclerosis
-
Undersized cuffs OVERestimate, Oversized cuffs UNDERestimate.

*** Patients who are older or have a long history of diabetes may have non-compressible brachial arteries, producing pseudohypertension.***

Proper cuff size selection is critical to accurate measurement. The bladder length and width of the cuff should be 80% and 40%, respectively, of the arm circumference.

Korotkoff sounds should be used to measure blood pressure. Compared with intra-arterial blood pressure, these sounds generally produce REDUCED systolic blood pressure values and HIGHER diastolic values.

Hypertension. 2005;45:2-21
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Front 5

EZ12

Soda lime contains:

A. Ca(OH)2 80%, NaOH 20%

B. Ca(OH) 2 94%, NaOH 4%, KOH 1%

C. Ca(OH) 2 80%, Ba(OH) 2 20%

D. Ca(OH) 2 40%, NaOH 60%

Back 5

B. Ca(OH) 2 94%, NaOH 4%, KOH 1%
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Front 6

EZ36a ANZCA version [2003-Aug] Q132, [2004-Apr]
The values of static vacuum and minimum gas flow recommended for satisfactory anaesthetic and surgical suction are
A. 40 Kpa and 40 l.min-1
B. 40 Kpa and 60 l.min-1
C. 50 Kpa and 30 l.min-1
D. 60 Kpa and 40 l.min-1
E. 60 Kpa and 50 l.min-1

Back 6

D. 60kpa and 40 l.min-1
-
Ref. Chris Thompson. Suction systems. 2010

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Front 7

EZ45

Third wire in a mains power supply is:

A. Needed so fuse will blow if fault from active to case of equipment

B. Necessary to carry the extra power for 3-phase equipment

C. To prevent a spark

D. To prevent electrocution if the active wire is contacted

E. Coloured green and white

F. Prevents microshock

Back 7

A. Needed so fuse will blow if fault from active to case of equipment

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Front 8

EZ51

With a back-pressure compensated ball flowmeter

A. a 25 degree tilt from vertical will cause an over-reading of approximately 50%

B. increasing the outlet resistance will decrease the flow reading without affecting the flow

C. the flow control spindle is on the inlet side of the float chamber

D. accuracy of the reading is dependent on using a gas supply with the correct inlet pressure

E. a leak in the outer chamber will NOT influence the accuracy of the flow reading

Back 8

D. accuracy of the reading is dependent on using a gas supply with the correct inlet pressure

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Front 9

EZ55

When performing laser surgery on the airway

A. instruments with high reflectance are desirable

B. poly-vinyl chloride (PVC) endotracheal tubes are more easily penetrated by the laser beam than red rubber tubes

C. PVC tubes are more flammable than red rubber tubes

D. the volatile anaesthetic agents support combustion

E. the CO2 laser beam is reflected by moistened cotton swabs

Back 9

B or C?
-
B. poly-vinyl chloride (PVC) endotracheal tubes are more easily penetrated by the laser beam than red rubber tubes - depends on the type of laser: "Modern PVC strongly absorbs far-infrared light and is very sensitive to CO2 laser energy... In vitro PVC is transparent and therefore immune to Nd:YAG and visitble laser light; however a thin coating of mucus or blood in vivo can absorb energy and restore the hazard." (Miller 6th Ed p.2581)
C. PVC tubes are more flammable than red rubber tubes - probably the best answer but depends on definition of flammability: PVC definitely more easily ignited. "PVC ignited and developed intense flame the soonest, resulting in widespread deposit of carbonaceous debris... Red rubber tubes were more resistant to ignition, and produced less debris and inflammation." (Miller 6th ed p.2581) However PVC has a higher flammability index according to Wolf and Simpson who found that PVC required a higher FiO2 than red rubber or silicon to maintain combustion.
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Front 10

EZ60

When working with surgical lasers

A. the eyes can be protected from YAG laser emission by ordinary glasses with side shields

B. the reflected laser beam is safe to view

C. the emission from the CO2 laser is invisible

D. protective eyewear is needed for all Class 1 lasers

Back 10

C. the emission from the CO2 laser is invisible


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Front 11

EZ60b ANZCA version [2003-Aug] Q137, [2004-Apr] Q24

Correct statements regarding medical laser hazards include all of the following EXCEPT
A. carbon dioxide lasers can cause corneal opacification
B. carbon dioxide laser energy is readily absorbed by most tissues
C. in general, the shorter wavelength lasers are more strongly absorbed by tissues and the longer wavelength lasers are more scattered
D. Nd:YAG (neodymium:yttrium-aluminium-garnet) lasers can injure the retina
E. the effect that a particular laser beam has on tissue depends on its wavelength and power density

Back 11

C. in general, the shorter wavelength lasers are more strongly absorbed by tissues and the longer wavelength lasers are more scattered
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Front 12

EZ62 [Apr05][Sep05][Mar06]

Precautions when providing anaesthesia for surgery using a Nd-YAG laser should include all of the following EXCEPT

A. avoidance of nitrous oxide

B. scavenging of smoke particles because they may contain viral DNA

C. awareness that gas embolism is possible from cooling gas down laser conduit

D. use of sunglasses to protect eyes

E. avoidance of an FiO2 above 0.4

Back 12

D. use of sunglasses to protect eyes
-
A. avoidance of nitrous oxide. true - flammable

B. scavenging of smoke particles because they may contain viral DNA - true.

C. awareness that gas embolism is possible from cooling gas down laser conduit - true - From Miller 7th ed: "The Nd:YAG laser system has been associated with venous gas embolism. Embolization has been a particular problem during hysteroscopic surgery with Nd:YAG contact probes when the gas coolant for the sapphire probe tip has accidentally inflated the uterine cavity. "

D. false and answer to choose - must be laser protective glasses not sunglasses.

E. true - to reduce risk of fire

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Front 13

EZ64

The BEST way to avoid carbon monoxide accumulation in circle circuit:

A. Change sodalime each morning before list

B. Use desflurane instead of sevoflurane

C. Use baralyme instead of sodalime

D. Turn off gas flows when not in use

E. Flush system prior to use if period of non-use

Back 13

D. Turn off gas flows when not in use

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Front 14

EZ65

Factors contributing to carbon monoxide accumulation in a circle absorber anaesthetic circuit include

A. fresh baralyme

B. sevoflurane

C. exhausted baralyme

D. halothane

E. desflurane

Back 14

E. desflurane


Desflurane produces the most CO

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Front 15

EZ67

The laryngeal mask when correctly inserted

A. may be safely used in a patient with latex allergy

B. lies with the sides facing the pyriform fossa

C. lies with the upper border under the base of the tongue

D. forms a seal around the laryngeal perimeter

E. has the black line on the tube, always facing the lower lip of the patient

Back 15

A. may be safely used in a patient with latex allergy (?most true)
-
ABCD all true. E - false - black line faces upper lip.
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Front 16

EZ68

Carbon monoxide production by soda lime degradation of volatile anaesthetic agents, is LEAST likely to occur with

A. the first case of the day and the use of isoflurane

B. the first case of the day and the use of sevoflurane

C. the first case of the day and the use of desflurane

D. fresh soda lime and the use of desflurane

E. fresh soda lime and the use of sevoflurane

Back 16

E. fresh soda lime and the use of sevoflurane
-
The anesthetic used: for a given minimum alveolar anesthetic concentration (MAC)-multiple, the magnitude of CO production (greatest to least) is Desflurane > enflurane > isoflurane >> halothane = sevoflurane. (Ref: Anesth Analg 1995; 80:1187-93)


In summary regarding CO production:

Baralyme > Sodalime;
Dry > fresh
D>E>I>S=H
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Front 17

EZ69

When a circle absorption system and tracheal intubation are in use with an adult subject, rebreathing of expired gas becomes practically negligible if

A. spontaneous breathing is replaced by intermittent positive pressure breathing

B. the minute volume is 8 L.min-1 or more

C. the carbon dioxide absorbent is fresh and has an intergranular space of at LEAST one litre

D. a fresh gas flow rate of at LEAST 8 L.min-1 is used

Back 17

D. a fresh gas flow rate of at LEAST 8 L.min-1 is used
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Front 18

EZ70 [Apr08]

Significant differences between the LMA-ProSeal™ and the standard laryngeal mask (LMA-Classic™) include all of the following EXCEPT

A. a built in bite-block

B. a double cuff arrangement

C. an improved seal pressure at a given cuff pressure

D. an independent oesophageal drain tube

E. improved aperture bars to prevent the epiglottis occluding the airway tube

Back 18

E. improved aperture bars to prevent the epiglottis occluding the airway tube
-
A. a built in bite-block - true
B. a double cuff arrangement - true
C. an improved seal pressure at a given cuff pressure - true: "High seal pressure - up to 30 cm H20 - Providing a tighter seal against the glottic opening with no increase in mucosal pressure" [1]
D. an independent oesophageal drain tube - true: "A built-in drain tube designed to channel fluid away and permit gastric access for patients with GERD or during extended cases where endotracheal intubation is not required"
E. improved aperture bars to prevent the epiglottis occluding the airway tube - false and answer to choose

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Front 19

EZ71 [Aug04]

The most important operating theatre hazard during the use of laser for ophthalmic procedures is

A. burns to the skin of theatre personnel

B. combustion of patient drapes

C. combustion of surgical tubing

D. eye damage to theatre personnel

E. unintended burns to patient retina

Back 19

D. eye damage to theatre personnel
vs B. combustion of patient drapes
-
Stan - D
Prev grp - B
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Front 20

EZ72 ANZCA version [2004-Apr] Q147, [Jul06] Q78, [Apr07]

The output of a diathermy machine does NOT cause patient electrocution because the

A. current is too low

B. current travels on the surface of the body

C. frequency is too high

D. return electrode is never placed between the heart and the operating site

E. voltage is too low

Back 20

C. frequency is too high

-
As the frequency of the driving voltage increases, the heating effect increases and the stimulation decreases. Therefore, at frequencies above 100 kHz (i.e. radio frequencies) the effect is entirely heating.
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Front 21

EZ73 [May09][Mar10]

The electrical requirement that distinguishes a "cardiac protected area" from a "body protected area" is the

A. equipotential earth

B. isolation transformer

C. line isolation monitor

D. maximum leakage current to patient limit of 500 microamperes

E. residual current device

Back 21

A. Equipotential earth
-
Need a class A area for a cardiac protected area.

Class Z
Fuse Boxes which limit the maximum current through the active wire.
8 Amp fusewire for lighting circuits
15 Amp for power
Standards limiting the amount of current through any set of power outlets.
+ Class B
As for Class Z Areas plus:
Earth-leakage detection devices must be used, ie Earth Leakage Core Balance Relays (RCD's) or Isolating transformers with Line Isolation Monitors.
The earth wiring must be used and tested regularly for low resistance.
All equipment having patient circuits must be class BF or CF.
+ Equipotential Earth = Class A


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Front 22

EZ75

The patient plate of some diathermy units has two separate areas and two wires to allow for

A. a back-up if one area fails

B. bipolar cautery

C. capacitive coupling to the patient

D. coagulation and cutting currents

E. return electrode monitoring

Back 22

E. return electrode monitoring
-
With unipolar diathermy or cautery, the full surface of the return (grounding) pad or plate must fully contact the patient’s skin surface to minimize the risk of burns. An alarm will sound if the resistance across the pad or plate increases, indicating a reduction in the contact area.
Ref: Atlee. Complications in anesthesia.
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Front 23

EZ76

Residual Current Devices (also known as Safety Switches)

A. detect differences in current between the active and neutral wires of a circuit

B. isolate the patient from earth

C. monitor the isolation of the power line

D. must be fitted to all Cardiac Protection areas

E. must be fitted to all operating theatres

Back 23

A. detect differences in current between the active and neutral wires of a circuit
-
Pipeline pressure is 4 atmospheres which is approximately:

60 psi
4 bar or
400kPa
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Front 24

EZ77

The pressure in wall oxygen gas supply pipelines in operating theatres is

A. 100kPa

B. 200kPa

C. 300kPa

D. 400kPa

E. 600kPa

Back 24

D. 400kPa
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Front 25

EZ78 [Jul06]
Regarding ball flowmeters the

A. flow control knob cannot stop gas leakage if the glass chamber is broken

B. flowmeter maintains accuracy when tilted

C. flowmeter will over estimate gas flow if connected to a high resistance device such as a nebuliser

D. gas flow rate is read at the centre of the ball

E. gas flow lifts the ball up in a parallel sided tube in the glass chamber

Back 25

A. flow control knob cannot stop gas leakage if the glass chamber is broken
-
A. TRUE - Because the flowmeter is pressurized with the needle valve downstream of the flowmeter, fracture of the top chamber allows a free flow of gas which cannot be controlled by the flow knob.
B. FALSE - It is important that the flow tube be vertical, as the force of gas flowing up the flowmeter tube lifts the ball against the force of gravity.
C. FALSE - The chamber is pressurized by the inlet pressure and minor degrees of outlet occlusion do not alter the flow.
D. FALSE - Ref: Gopal Mandal. Measurement of volume and flow in gases. AIC 2008. 10:1:52-6. HOWEVER, American ball flowmeters are usually read at the centre of the ball. In Britain, New Zealand and Australia, flowmeters should be read usually at the top of the ball.
E. FALSE - The ball is lifted up a conical tube...
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Front 26

EZ79 [May09][Mar12] [Aug12]

An infant is anaesthetised and ventilated using an endotracheal tube and circle breathing system with C02 absorber. The item which causes the most resistance to breathing is the

A. airway pressure limiting (APL) valve

B. circuit hosing

C. endotracheal tube

D. heat and moisture exchange filter

E. inspiratory and expiratory valves

Back 26

C. endotracheal tube
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Front 27

EZ80 ANZCA Version [Mar06] Q150, [Jul06] [Sep11][Mar12]

Line isolation monitoring protects against microshock

A. In no circumstances

B. Only when all equipment in region is monitored

C. As long as the hazard current is set to 30 milliamps

D. As long as the hazard current is set to 10 milliamps

E. Only if grounded equipment is used.

Back 27

A. In no circumstances

line isolation a monitor only
need equipotential grounding to protect against microshock
--
Isolating Transformers and Line Isolation Monitors.
These are the more expensive alternative to RCD's (Residual Current Devices) and are widely used in operating theatres because they do not disconnect the power when a fault is detected, yet provide safety should such a fault exist.
The first component is a large transformer (the Isolating Transformer) mounted in the wall cavity which converts the earth-referenced mains supply to a "floating" supply. The floating supply provides 240V between two active wires, but because the supply is not earth-referenced, the presence of an earth circuit through the patient or anyone else is perfectly safe and no current will flow. All the circuit to earth does is to reference the floating supply to earth; no current actually flows through the earth connection.
The Line Isolation Monitor continually checks that the floating supply is not earth-referenced, and indicates on a dial how much current could flow to earth if there was an earth connection. If the potential earth current would be more than 5mA an alarm will sound, alerting the anaesthetist to the presence of a loss of the "floating" nature of the supply. It does this by intermittently connecting one of the two active wires to ground through a very large resistance. If the other wire is connected to ground a circuit will be formed and current will flow, and this indicates how much current would flow through the circuit if either of the two active wires are connected to ground.
As with an RCD the device will not alarm under 5mA, so microshock may still occur unnoticed, however macroshock is very unlikely; only current flowing through the patient from between the active wires will no be detected. (Electricity and electrical hazards
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Front 28

EZ81 ANZCA Version [Jul06] Q116

The Classic laryngeal mask airway (LMA - Classic™)

A. contain plasticisers (phthalates), which may be carcinogenic
B. involves a significant risk of prion transfer
C. is cheaper to use than disposable LMAs
D. is less permeable to N2O than disposable LMAs
E. may be reused 40 times

Back 28

E. may be reused 40 times
-
A. contains plasticisers (phthalates), which may be carcinogenic – False. All PVC single-use laryngeal masks are made of phthalate-containing PVC.
B. involves a significant risk of prion transfer – False. A ‘worse case scenario’ of the theoretical risk of prion transfer from an anaesthetic airway to be between 1 and 10 in 100 000.
C. is cheaper to use than disposable LMAs – False. About the same.
D. is less permeable to N20 than disposable LMAs - False. PVC has two advantages over silicone: first it is cheaper and second nitrous oxide diffuses through it less readily, so intracuff pressure alters little during anaesthesia. E. may be reused 40 times
Ref: Cook. The classic laryngeal mask airway: a tried and tested airway. What now? British Journal of Anaesthesia 96 (2): 149–52 (2006).
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Front 29

EZ82

Using a Proseal LMA, properly fitted, what pressure can you ventilate to before leak occurs?

A. 10cmH20

B. 20cmH2O

C. 30cmH2O

D. 40cmH2O

E. 50cmH20

Back 29

C. 30cmH2O


JB BJA article 2000 aug
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Front 30

EZ83 [Mar06]

Regarding perioperative use of processed salvaged red blood cells,

A. malignant cells are removed by the washing process

B. storage of salvaged cells should be limited to six hours

C. the high free haemoglobin levels are associated with renal failure

D. the salvaged cells have lower oxygen carrying capacity than banked blood

E. the survival of the salvaged red blood cells is significantly impaired

Back 30

C. the high free haemoglobin levels are associated with renal failure
-
From Perioperative Cell Salvage CEACCP 2010:
A. malignant cells are removed - false - 'Cell salvage is not recommended by the manufacturers in patients undergoing surgery for malignancy because of the possibility of rein fusion of tumour cells, potentially giving rise to distant metastasis.'
B. storage of salvaged cells limited to 6 hours - false - 'The collected red cells can be rein fused immediately or for up to 4 hours after process if kept at room temperature.'
C. True - 'Other complications include haemolysis and increased amounts of free haemoglobin, which can lead to renal damage.'
D. and E. - false - Miller 7th Ed Ch 58 - 'The survival of recovered blood cells appears to be at least comparable to that of transfused allogenic red blood cells.
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Front 31

EZ84 [Apr07][Oct09]

You are performing a Level 2 check on the anaesthetic machine. The suction bulb at the common gas outlet does not stay compressed after 10 seconds. The cause of this could be:

A. leak in CO2 absorber

B. loosely seated vaporiser

C. leak in pipeline O2

D. leak in cylinder attachment to anaesthetic machine

E. malfunction in one of the valves of the ventilator circuit

Back 31

B. loosely seated vaporiser


The bulb negative pressure test is a test of the low-pressure circuit involving the vaporisers and flowmeters.

These tests, however, do not replace the negative pressure test recommended by Datex-Ohmeda and Dräger for leaks in the machine proximal to the common gas outlet. To perform this test, a no-flow state is first achieved by turning off the machine. The hose connected to the fresh gas outlet is then removed, and the leak detector device (essentially a suction bulb) is attached. After all of the gas is removed from the machine, a flowmeter is opened, and the suction bulb is compressed until it stays flat. If the bulb does not reinflate in 30 seconds, the flowmeter is considered safe. The remaining flowmeters and vaporizers are tested individually in the same way. If all pass, the machine is safe for use. If the machine does not pass, it should be removed for servicing.

Anaesthesia Secrets
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Front 32

EZ85 ANZCA version [Apr07] [Jul07] [Aug12]

In a rotameter the:

A. Bobbin spins inside a tube that has parallel sides

B. Flow is laminar at high flow rates

C. Height of the bobbin is proportional to the pressure drop across the bobbin

D. Pressure drop across the bobbin is constant at varying flows

E. Resistance increases with increasing gas flow

Back 32

D. Pressure drop across the bobbin is constant at varying flows - true:

"The Rotameter and the Wright peak flow meter are examples of variable orifice flowmeters. Constant pressure in the former is provided by the pressure of the bobbin; the pressure is the ratio of the product of the mass and gravity over the cross sectional area of the bobbin (p = F/A = m a/A). The Rotameter is tapered, and thus the magnitude of the orifice around the bobbin corresponds to the magnitude of gas flow." (Basic science for anaesthetists).

From AnaesthesiaUK website:

"Rotameters are widely used in gas delivery systems for continuous flow measurement. Several designs have been used, though now almost all use a vertical tapered tube containing a bobbin or ball which is supported by the gas flow as it passes upwards through the tube.
The weight of the bobbin (and thus the pressure drop required to support it) is constant, but as the flow increases its position in the tube rises, lowering the resistance as a larger pathway is created alongside the bobbin.

Amalgamation of the space for gas flow around the bobbin to equate to a simple pathway reveals that at the bottom of the flowmeter the resulting dimensions lead to laminar flow but at the top of the tube produce turbulent flow. The physical characteristics of the gas that determine the resulting flow are therefore viscosity at the bottom and density at the top of the tube. The main implication of this is that calibration of rotameters is gas-specific and for accuracy its use must be restricted to that gas. Calibration is usually done to read the flow rate from the top of a bobbin but the centre of a ball.

The range of gas flow measurements can be increased by using two tubes (one for low and one for high flow rates), or by varying the taper so that a greatly increased diameter results at the top of the tube.

Inaccuracy results from anything that causes the bobbin to stick in the tube, including dirt or static electricity. To prevent build-up of static, the inside walls of a rotameter and its mounting points are made of conductive material. To demonstrate that the bobbin is not stuck, it has angled flutes to produce rotation, which is made easier to see by appropriate colouring.

Back pressure caused by downstream resistance also leads to an inaccurately low reading on a rotameter, though the actual flow is the same as that shown before the resistance was applied."
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Front 33

EZ86 [Apr07][Jul07]

Adult male who is intubated and ventilated, with CVL in situ. Just before surgeon starts the Line Isolation Monitor alarms about a leak at 5mA. What do you do?

A. stop procedure and move to a safe location

B. sequentially remove non essential monitors from the circuit until fault is identified

C. unplug the CVL to electrically isolate it until fault is identified

D. ensure the patient is earthed

E. Check the diathermy pad

Back 33

B. sequentially remove non essential monitors from the circuit until fault is identified

Want to avoid macroshock

Line isolation is not for microshock!
Want to avoid microshock = VF
--
Much debate vs C. unplug the CVL to electrically isolate it until fault is identified

If LIM alarms a leak - there is a leak to the ground. If you touch the patient (and their CVL) you can theoretically complete the circuit and give them a microshock.
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Front 34

EZ87 [Sep05][Mar06]

With regard to accidental electrocution, which statement is true?

A. All electrical equipment should be earthed

B. Risk of VF increases with increasing frequency

C. Risk of VF increases with greater with alternating current

D. Risk of electrocution is reduced by earthing the patient

E. Use of battery operated equipment avoids the risk of VF

Back 34

C. Risk of VF increases with greater with alternating current
-
A equipment supplied by an isolated circuit is not earthed

B diathermy does not cause electrocution because of its very high frequency

C AC is more arrhythmogenic than DC - so this is the answer

D Should not earth them

E probably not if you connect the equipment up to their pacing wires
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Front 35

EZ88 [Apr08][Oct08][Mar10][Aug10]

A device that detects a 10mA difference in active and neutral leads and causes turning off of the circuit within 40 ms. This is a:

A. Class 1 device
B. Equipotential earthing
C. Line isolation monitor
D. Residual Current Device
E. Fuse

Back 35

D. Residual Current Device
-
From wiki
A Class 1 device = earthed, insulated wires, fuses within equipment
B Equipotential earth is a mechanism where the casings of all the equipment in theatre are earthed to the same potential so there can't be a potential difference between two live casings which would be potential source for macro or microshock (green and yellow cabels)
C Line isolation monitor detects leakage currents >5mA and sounds an alarm, it does not automatically shut anything off
D = detects current leakages and then shuts off supply- not so good if there is life saving equipment being used, e.g. CPB
--
Prev grp:
*** The RCD will disconnect power within 10 to 20 milliseconds when a leak current of 5 to 10 mA is detected. Thus it will protect against most cases of macroshock. An audible alarm will sound and a loud thump will be heard when the relay is tripped, and power can only be restored manually, by pushing the switch back to the "on" position.***

Class 1 Device - earthed, Class 2 - double insulated, Class 3 - low voltage (<40V DC)

The LINE ISOLATION MONITOR continually checks that the floating supply is not earth-referenced, and indicates on a dial how much current could flow to earth if there was an earth connection. If the potential earth current would be more than 5mA an alarm will sound, alerting the anaesthetist to the presence of a loss of the "floating" nature of the supply. (ALARM ONLY)

Equipotential earthing is installed in rooms classified as 'Cardiac Protected' electrical areas. Equipotential earthing in treatment areas used for cardiac procedures is intended to minimise any voltage differences between earthed parts of equipment and any other exposed metal in the room.

This reduces the possibility of leakage currents that can cause microelectrocution when the patient comes into contact with multiple items of equipment, or if the patient happens to come into contact with metal items in the room while they are connected to a medical device.

All conductive metal in an equipotential area is connected to a common equipotential earth point with special heavy duty cable.
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Front 36

EZ89 [May09]
Why does a proseal LMA provide a better airway seal?
A. More stable position due to oesophageal tube
B. Dorsal cuff pushes ventral cuff...?
C. Presence of oesophageal lumen
D. Higher cuff pressure
E. ?

Back 36

B. Dorsal cuff pushes ventral cuff.
-
See wiki
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Front 37

EZ90 [May09]

Which of the following is the most frequent complication after use of LMA?
A. dysphagia
B. dysarthria
C. sore throat
D. hoarse voice
E. dry mouth

Back 37

E. Dry mouth
-
see wiki
Stan says E.
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Front 38

EZ91 [TMP-Jul10-065]

Which gives the BEST seal?
A. LMA classic
B. Proseal
C. Intubating LMA
D. ?Disposable Supreme
E. ?Flexible

Back 38

B. Proseal
-
see wiki.
Previous group said iLMA - study comparing seven supraglottic devices in CADAVERS and oesophageal pressures were measured in terms of determining which were the most leak proof.
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Front 39

EZ92 [TMP-Mar10-075]
Which can deliver minute ventilation of greater than 5L/min using a 14 G cannula used for needle cricothyroidotomy
A. jet ventilation using pressure 400KPA
B. oxygen flush button on anaesthetic machine
C. oxygen tubing on oxygen port on anaesthetic machine at 12L/min
D.
E. none of the above

Back 39

A. jet ventilation using pressure 400KPA
-
C. true only if 15L/min

Ref: Flint et al. Comparison of different methods of ventilation via cannula cricothyroidotomy in a trachea-lung model. BJA 2009. 103(6):891-5.
See table 2.

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Front 40

EZ93 [Sep11][Aug12]

What is the chemical used in soda lime to indicate exhaustion
A. ethyl violet
B. potassium permanganate
C. ?

Back 40

A. Ethyl violet

Ethylviolet is a pH-sensitive triarylmethane dye used as an indicator in CO2-absorbents. It changes from colorless to blue/violet.
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Front 41

EZ94 (Mar12)[Aug12]

A home handyman leaves his electricity turned on whilst fiddling with wires [repairing a power outlet]. He has a RCD. What happens if he touches the neutral and ground wires?

A. Nothing will happen
B. Receives macroshock
C. Protected from macroshock by RCD
D. Protected from microshock by domestic fuse
E Receives microshock

Back 41

A. Nothing will happen
- For current to flow, there must be a complete circuit from one voltage terminal (LIVE) via the body to the other terminal (NEUTRAL). The GROUND or earth wire returns leaks from the equipment back via the earth (instead of anyone who may touch it).
Theoretically nothing should happen if he was to touch the neutral and ground wires.

B. Receives a macroshock - this would be the case if he touched the active and neutral simultaneously.
--
From 'Electrical hazards causes and prevention' Anaes Int Care Med:
A residual current device is much more sensitive and can break a circuit before a person perceives any pain. This relies on the principle that normally in a correctly working system there is a balance of current in the live and neutral leads. In a fault situation, there is an imbalance of current and this causes an electrically operated switch to break the circuit.

HOWEVER - if he touches active an neutral wire AT THE SAME TIME - no difference in current is detected and the current will pass through him causing a shock.

From http://www.allstatesafety.com.au/services/rcd-residual-current-device-safety-switch/
What an RCD will not protect;
If a user was to touch both active and neutral at the same time, then current flow would be even through both circuits. RCD WON’T TRIP
Scenario #1 A carpenter using a tool with an internal fault, can be electrocuted from a positive to neutral connection, because both positive and neutral would be feeding electricity evenly into the body, hence the RCD wouldn’t trip.
Scenario #2 An ice machine with a faulty earth and a positive short to it metal frame is touched by a user; positive could flow into the users hands join the neutral side within a fan or compressor. This would happen because an earth wasn’t present. Electrons always take the path of least resistance. If a good earth contact was present then as soon as a positive short was made to the frame positive would have gone to earth and its amperage would have been higher than the negative, therefore the RCD would have tripped.
In basic terms if you short;

• Positive to earth – RCD Trips
• Positive to negative with a good earth – RCD Trips
• Positive to negative – RCD wont trip
• Positive to a metal frame with no earth – RCD wont trip
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Front 42

EZ95 [Mar12]

What is the oxygen concentration in a standard bottle of heliox?

a. 21%
b. 25%
c. 30%
d. 33%

28% was NOT an option

Back 42

a. 21%
--
see blank bank wiki entry on heliox.
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Front 43

EZ96 [TMP-Mar12-036]

A size C oxygen cylinder that reads 5000kpa contains approximately how many litres of oxygen

a. 100
b. 150
c. 200
d. 350
e. 600

Back 43

b. 150
--
Cylinders for gases are filled to 13700kPa (2/3 of rated pressure)

(5000/13700) x 440L = ~150

ref: Chris Thompson Gas Supplies notes (last updated Mar 12)
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Front 44

EZ97 [Mar12]

How much air is the maximum to that should be used to inflate a 5 LMA classic cuff

a. 15

b. 20

c. 25

d. 40

e. 45

Back 44

d. 40
--
ref: BJA 1998; 80: 470-474
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Front 45

EZ98 [Mar12]

A machine with a soda lime absorber was left on overnight with oxygen running at 6 litres per minute. In the morning a desflurane vaporiser is connected. What toxic substance may be produced?

A. Substance A
B. Carbon monoxide
C. Carbon dioxide
D. Calcium hydroxide
E. Substance B

Back 45

B. Carbon monoxide
--
From Stoelting:
'Carbon monoxide formation reflects degradation of volatile anaesthetics that contain a CHF2 moiety (des, enf and iso) by the sting bases in desiccated CO2 absorbents. Factors which influence magnitude of carbon monoxide production from volatile anaesthetics include:
- dryness of CO2 absorbent with hydration preventing formation
- high temperatures of CO2 absorbent as during low fresh gas flows and/or increased metabolic production of CO2
- PROLONGED HIGH FRESH GAS FLOWS THAT CAUSE DESICCATION (DRYNESS) OF THE CO2 ABSORBENT, and
- type of absorbent

Desflurane produces the highest carbon monoxide concentration (then enf and iso).
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Front 46

New: Photograph of an Arndt endobronchial blocker. Orifice labelled 'X'. What goes in 'X'?

A. Bronchoscope

Back 46

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Front 47

Rpt: A Full Size C oxygen cylinder has pressure downregulated from?

A. 16,000 kPa to 400 kPa
B. 16,000 kPa to 240 kPa
C. 11,000 kPa to 400 kPa
D. 11,000 kPa to 240 kPa

Back 47

A. 16000 kPa to 400 kPa
-
See RAH presentation.
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Front 48

TMP-136 [Apr08] Q96

When obtaining an image using ultrasound, the most effective way to improve the spatial resolution is to increase the:

A. 2D gain
B. frame rate
C. single scatter
D. time gain compensation
E. transducer frequency

Back 48

E. transducer frequency
-
Spatial resolution of any imaging system is defined as its ability to distinguish two points as separate in space.
It is commonly further subcategorised into axial and lateral resolution.
Axial resolution is resolution in direction parallel to the US beam. The resolution at any point along the beam is the same; therefore axial resolution is not affected by depth of imaging.

Axial resolution = spatial pulse length/2 or (# cycles in the pulse x wavelength)/2

Clearly, from the above equation we can see that any measure that shortens the length of the ultrasound pulse will improve axial resolution. For example, decreasing the number of cycles in the pulse or increasing the frequency of the pulse should improve axial resolution.

By way of contrast, lateral resolution is defined as the ability of the system to distinguish two points in the direction perpendicular to the direction of the ultrasound beam. Lateral resolution is affected by the width of the beam and the depth of imaging. Wider beams typically diverge further in the far field and any ultrasound beam diverges at greater depth, decreasing lateral resolution. Therefore, lateral resolution is best at shallow depths and worse with deeper imaging.
--
B. frame rate - relevant for temporal resolution not spatial?
Temporal resolution is the ability to detect that an object has moved over time. For the purposes of medical ultrasound, temporal resolution is synonymous with frame rate. Typical frame rates in echo imaging systems are 30-100 Hz. The temporal resolution or frame rate = 1/(time to scan 1 frame). The time to scan one frame is equal to the pulse repitition period x number of scan lines per frame.

Common means of improving frame rate include 1) narrowing the imaging sector, which decreases the time it takes to scan one frame 2) decreasing the depth which decreases the PRP 3) decreasing the line density, which requires fewer lines to scan one frame (at the cost of spatial resolution) 4) turning of multifocus, which decreases the number of pulses needed per line.
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Front 49

TMP-Mar11-030
Flow with the O2 flush button pressed and volatile agent turned on will give you:
A: 20-30l/min O2
B: 30-70l/min O2
C: volatile agent + 30l/m O2
D: volatile agent + 40l/m O2
E: volatile agent + 50l/min O2

Back 49

B: 30-70l/min O2
-
From Complications in Anesthesiology (online textbook via anzca):
'An O2 flush valve that is held open for a prolonged time period exposes the breathing circuit to high gas flows (35-75L per minute) and excessive airway pressures can rapidly develop.'
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Front 50

TMP-Mar11-043
What is the most common way to measure end tidal gas concentrations on our anaesthetic machines?
A: mass spectometry
B: Raman scattering
C: ultrasonic
D: infrared
E: piezoelectric

Back 50

D: infrared
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Front 51

TMP-Mar12-014

Where should the tip of an IABP lie

a. 2cm distal to the left subclavian

b. 2 cm proximal to the left subclavian

c. 2cm proximal to the renal artery

d. 2 cm distal to the renal artery

Back 51

a. 2cm distal to the left subclavian

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Front 52

TMP-Mar12-018 [Aug12]

What is a contraindication to an IABP?

A. Aortic regurgitation

B. Aortic stenosis

Back 52

A. Aortic regurgitation
--
CEACCP 2009 article:
CONTRAINDICATIONS
Absolute - AR, aortic dissection, Chronic end-stage heart disease with no anticipation of recovery, aortic stents
Relative - uncontrolled sepsis, AAA, tachyarrhythmias, severe peripheral vascular disease, major arterial reconstruction surgery

INDICATIONS
AMI, cardiogenic shock, Acute MR and VSD, Catheterization and angioplasty, refractory unstable angina, refractory LV failure, refractory ventricular arrhythmias, cardiomyopathies, sepsis, infants and children with complex cardiac anomalies.
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Front 53

TMP-Oct09-032
In body protected OR with a Line Isolation Monitor reading 0 mA. If you touch one active wire what will happen.
a. nothing, because no connection to earth is completed
b. you get shocked
c. nothing because the floor is insulated
d. nothing because your shoes are nonconductive
e. RCD trips

Back 53

a. nothing, because no connection to earth is completed
-
0mA means everything is fine and properly isolated so the circuit is not earth referenced.
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Front 54

TMP-Oct09-045
Endotracheal tube to circuit connectors
a. 15/22 mm
b. lots of other wrong combo's

Back 54

a. 15/22 mm

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Front 55

TMP-Oct09-046
Appropriate infection control measures when anaesthetising a patient with suspected variant-CJD, the airway equipment should be

a. thrown away
b. plastic sheath, reuse
c. sterilization with ethylene oxide
d. sterilization with heat at 134 degrees for 3 minutes
e. Autoclave

Back 55

a. thrown away
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Front 56

TMP-Sep11-031

The safe maximal pressure for endotracheal cuff at the lateral side of the trachea
A. 0-10 cm water
B. 10-20 cm water
C. 20-30 cm water
D. 30-40 cm water
E. 40-50 cm water

Back 56

C. 20-30 cm water

Previous group said D - I disagree. See BMC Anesthesiology 04 article.
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Front 57

TMP-Sep11-110
NEW
Indicates autonomic neuropathy except
A. Sinus arrhythmias
B. Gastric reflux
C. Postural hypotension

Back 57

all of these can occur

Orthostatic hypotension is often the first recognised symptom and is typically most disabling

GI - constipation, episodic diarrhoea, early satiety, increased gastric motility, dysphagia, bowel atony, bowel incontinence, gastroparesis in DM (which may cause food stasis and subsequent vomiting), hypo salivation, altered taste, pre syncope with micturition and defacation

CVS - orthostatic onset of palpitations, nausea, presyncope

Sinus arrhythmias
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