Dmacs questions

Question 1

The Aide Mémoire for Recording and Transmission of Medical Data to Shore consists in 3 parts. What are they?

Answer 1

Part 1: obtain the initial essential information for transmission ashore in event of a medical emergency enable the onshore doctor to advise on immediate management of the casualty.

Part 2: collects more detailed information to provide a permanent record of the incident and to assist in accident analysis.

Part 3: provides a form for recording this information. This part will need to be used initially for the first examination and may need to be used repetitively at the request of the onshore doctor.

Note 1: useful to attempt to get photos
Note 2: For consistency, please use local time throughout.

Question 2

DMAC considers the only currently desirable form of physiological monitoring of a diver is …

a. respiration
b. heart rating
c. temperature

Answer 2

a. Respiration

Question 3

For divers operating below 50m, a speech processing system using oxy-helium breathing mixtures is …..

Answer 3

obligatory

Question 4

For monitoring purposes the partial pressure of a diver should be done at the point of delivery.
True or False

Answer 4

True

Question 5

A diver injured with HPWJ with no complaints should be?

Answer 5

Treated immediately and in remote locations watched for 4 or 5 days for signs of fever, rise pulse rate.
Indications of infection.

Question 6

What is the minimum partial pressure recommended for a supply on bailout for diving with oxy helium mixtures?

Answer 6

Maximum: 1.4 bar
Minimum: Same as primary breathing gas mixture, with a minimum of 0.4 bar.

Question 7

7. What is the absolute minimum oxygen helium mixtures allowed offshore?

Answer 7

The choice of mixture supplied should be left to the diving contractor but a minimum of perhaps 2% of oxygen should present no problems operationally from 50 to 150 metres, and from 150 metres a smaller percentage may be appropriate.
Note: It is recognised however that contractors may need to use pure helium as a calibration gas.

Question 8

What is the single most important criterion related to diver safety resulting from low frequency sonar?

Answer 8

Disorientation due to vestibular stimulation.

Question 9

About Sonar frequency attenuation.

Answer 9

Above 500 Hz: sufficient attenuation for helmeted divers

Below 500 Hz: Helmeted divers offers no advantage over hooded wetsuit in low frequencies

Between 400 - 500Hz: A 3mm neoprene wet-suit hood provides some hearing protection (10 dB) at shallow depth (<10 msw).

Question 10

After a successful completion of treatment in the chamber, how long does a diver has to wait before an intercontinental flight?

Answer 10

72h for all intercontinental flights

Note: for flights with 600m - 24h

Question 11

In nitrox diving operation, a diver spend 2h in the water, after he spends another 2h in the chamber for decompression. How long he should wait until fly home?

Answer 11

24h - for flights 600m
48h - for intercontinental flights

Note: Same procedure for Trimix and Air for exposure more than 4h under pressure

Question 12

Attempting to rewarm a hypothermic diver in the bell that can be recovered with a pressure seal intact could cause?

Answer 12

Vasodilation of the skin could be accompanied by hypovolemic shock and collapse.

Question 13

Any diver who has suffered from neurological decompression sickness should be allowed to continue diving as long as he has no clinical evidence of a significant neurological deficit.
Trueor False

Answer 13

TRUE

Question 14

It is not a requirement for the supervisor to hold a valid first aid qualification. Why?

Answer 14

In most circumstances responsibility for the provision of first aid will be delegated to a designated first aider

Question 15

During saturation diving, the number of diver medic trained required to be at pressure?

Answer 15

2 DMTs

Note:
Systems operating with chambers at different depths, all divers must retain rapid access to a trained DMTs.
One DMT must remain outside the chamber at all times for purposes of communications and provision of equipment. This role can be met by a rig medic or nurse or by a member of the dive team with medic training.

Question 16

What is the minimum distance allowed for seismic and diving activity to occur?

Answer 16

Within a distance of 30km (18.6 miles) a joint risk assessment should be conducted, between the clients/operators involved and the seismic and diving contractors in advance of any simultaneous operations.
The minimum safe distance, as determined from the risk assessment.

Note: Where diving and seismic activity are scheduled to occur within a distance of 45km (28 miles), it would be good practice for all parties to be made aware of the planned activity where practicable.

Question 17

Diving operation within 30km of a seismic vessel should be terminated if the noise exposure level….

Answer 17

• interferes with diver communications;
• is considered to exceed acceptable noise exposure levels;
• induces discomfort; or
• places the diver at risk in any other way.

Question 18

After a successful recovery treatment of a diver with a limb pain, how long should he wait until go back to diving?

Answer 18

7 days

Note: after recurrence or relapse requiring further recompression: 14 days

Question 19

A diver is diagnosed with Neurological sensory disturbance, how long should he wait until going back to diving after full treatment in the chamber?

Answer 19

28 days

Note: All other Neurological: 3 months

Question 20

You are at the diving control, who is responsible for the fisrt aid kit available in the room?

Answer 20

Diving Superintendent or Vessel Medic

Note: The Diving Supervisor needs to have access to this Medical Kit at all times.

Question on the final exam

Question 21

DMAC suggests there should be how many sets of first aid kit per living chamber?

Answer 21

1 set per 3 chambers stored in sat control and accessible

Question 22

What is the absolute minimum quantity of oxygen available to enable normobaric therapy required to reach any therapeutic facilities?

Answer 22

4 hours for each diver

Question 23

Diver inspired gas should be heated at what depth?

Answer 23

150m

Question 24

Lockout time should be limited to

Answer 24

4 hours - anyone bell run

6 hours - 3 man bell run: individual diver acting as the bell man on each third dive.

Question 25

Deep saturation dives in excess of 200m. What is the recommended surface interval?

Answer 25

28 days.

Question 26

What is the maximum recommendation of saturation exposure in normal circumstances?

Answer 26

28 days.
In exceptional circumstances it may be appropriate to consider a brief extension, but only with the written agreement of the diving contractor’s medical advisor, the divers and diving supervisors.

Note: A diver’s cumulative saturation exposure should not exceed 182 days in any 12 calendar months.

Question 27

After a 10 days saturation exposure, how long the diver has to wait to recommitted to another saturation?

Answer 27

5 days

Note:
The surface interval should not be less than 50% of the duration of the preceding saturation dive or 10 days whichever is the lesser.

Where a diver carries out two saturation dives separated by a shorter surface interval, the surface interval subsequent to the two dives should be not less than the duration of the longer of the two saturations.

Question 28

After surfacing from an oxy-helium saturation dive, symptoms tend to appear within….

Answer 28

6 hours of surfacing

Note: it is not possible to define the point in time after which there is effectively a zero risk: traditionally this has been set at 36 hours but there are exceptions.

Question 29

After a completion of oxy-helium or other saturation decompression, surface-orientated dives requiring decompression stops how far should the diver remain in a proximity of a two compartment chamber.

Answer 29

Within 20 minutes (Vicinity) for 4 hours.

They should then remain within two hours travelling time of a two compartment chamber until 12 hours post-surfacing.

Question 30

DCI symptoms appearing after finished saturation decompression can normally be treated using USN treatment table 6.

True or False

Answer 30

True

Note: No industrial standard has been established for such treatment

Question 31

State the higiene living measures to avoid infection in saturation.

Answer 31

shower once daily and after the bell run

Prophylactic ear drops each ear, 2 x day

Chamber walls and bulkheads and BIBS masks, 2 x week

Shower-heads should be removed and locked out for cleansing on the surface twice weekly.

Question 32

Routine swabs for microbe analysis from the ear canals of divers is not advisable.

True or False

Answer 32

True

Note: Such swabs should be reserved for use in divers with clinical features of otitis externa, such as pain, itch, or discharge.
Routine swabs from chamber surfaces both pre-dive and during saturation can be helpful as guides to the efficacy of cleansing regimes.

Question 33

A chamber in which any medical treatment will be carried out for saturation divers should be accessible by any diver in the system in a reasonable time of?

Answer 33

30-60 minutes, taking into account any need to change chamber pressure

Question 34

What are the requirements for a chamber in which any medical treatment will be carried out?

Answer 34

A minimum internal diameter of 1.8m but preferably exceeding 2.15m

The ability to remove, or move out of the way, bunks and other equipment normally fitted to the chamber but not needed directly for a medical emergency;

A bunk for the patient which should:

be waist high

have access from at least one side and preferably both, from the head end, have a firm base and be able to tilt the patient to 30° both at the foot and head ends

be provided with a mattress;

A tray or working surface for medical instruments;

A means for suspending IV drips overhead the patient;

A convenient medical lock of at least 300mm diameter;

A good communications system with connections in a suitable location for personnel beside the casualty;

Suitable extra lighting for the area of the casualty. This may be the normal bunk lights fitted with long leads to reach the treatment area;

Sufficient additional gas and electrical hull penetrations (in order to ensure that in an emergency appropriate gas and electrical supplies can be rapidly connected) as agreed with the specialist medical adviser (see sections below);

Sink facilities (with foot or elbow operated taps) to be provided in the vicinity of the patient’s bunk.

Question 35

In case of a disease diver body in saturation what action should be taken?

Answer 35

Notify regulatory authority (Police)

place the body in a body bag with the application of large amounts of absorbent material adjacent to all body orifices.

isolate the chamber.

reduce any heating.

decompress the body over a period of three to four hours.

do not freeze the body

Photos should be taken

Question 36

DMAC 31 State de Accelerated Emergency Decompression (AED) from Saturation. When this procedure offer the best opportunity for the divers’ survival?

Answer 36

• In the circumstances of the emergency may put the hyperbaric evacuation system (HES) out of action
• the sea state may prohibit launch of the HES or
• reception facilities for an evacuation system may not be available

Question 37

AODC09 states the emergency isolation of gas circuits in the event of rupture bell umbilical.

Answer 37

• The circuit supplying breathing gas to the diver(s) must be fitted with a non-return valve.
• As a principle, all gas or water circuits penetrating the bell should be equipped with shut-off valves inside and outside.
• All valves should be clearly labelled by name as well as by a number.
• An emergency water-proof list of all the valves thatmust be shuttoensure thepressure integrityinside all bells is tobeprovided inthebell. A duplicate mustbe kept onthe surface, and the contingency planmust provide for the shutting. The list shouldalso show thosevalves which must be left open.

Question 38

Bell Emergency Location Equipment Recommendations

Answer 38

• The Helle locator was incompatible with the Sonardyne transponder.
• Both systems (with the above reservation) operated well up to 545 metres, and thus exceeded the recommended specification of “maximum detectable range 500 metres”.
• The divers found the locators fairly easy to use, although they found it difficult to read the compass heading and range together, and it is recommended that on new equipment the two readings be displayed on the same panel.
• It is important that equipment be regularly serviced in accordance with the manufacturers recommendations.

Question 39

INSTRUCTIONS TO DIVERS ON SURVIVAL INSIDE A STRICKEN BELL

Answer 39

• The efficiency of passive thermal protection systems is totally dependent on their correct use. They should not be donned too early in the emergency when the bell internal atmosphere is still warm or else heavy sweating can occur leading to dampness and cold. Once the suits have been put on they should not be opened up unless absolutely necessary, as every slight opening can cause significant heat loss.
• Due to the enormous loss of body heat which would ensue, no attempt should be made to lock out of a stricken bell unless instructed to do so by the Diving Supervisor either directly, or via the rescue divers as per the tapping code.
• In the few locations which exist where bells are deployed in warm water, an assessment should be carried out locally on how to prevent the divers becoming overheated, and adequate provision made.
• Divers should ensure they are attached to whichever system of safety restraint is provided to maximise their safety during ascent and prevent blockage of the bell hatch in the event of unconsciousness.
• Ballast weights, where fitted, should not be released unless diver(s) are instructed to do so by the Diving Supervisor either directly, or via the rescue divers or in accordance with existing emergency procedures, as per the tapping code

Question 40

Emergency procedures and provisions for a included diving bell recovery

Answer 40

Provision should be made for disconnecting the bell wire and guide wires in the event that this becomes necessary.

When the bell is working at an intermediate depth consideration should be given to the operating position of the door so as to prevent flooding of the bell in the event of an uncontrolled descent.

An up-to-date photographic record and/or drawings should be available of the diving bell clearly indicating its features. In the event of an emergency, these records should be made available to whoever is in charge of the rescue.

Question 41

When sizing the bail out bottle, what should be considered in relation to the bell?

Answer 41

The diameter of the bell manway this will dictate the divers ease of entry into the bell

Question 42

What factor should be considered when deciding on the length of an umbilical?

Answer 42

• distance of the job from the proposed bell location
• duration of the divers bail out bottle at the depth.
• The diameter of the bell manway
• size of the bell in relation to the storage of the diver’s and bellman’s umbilicals.
• type of umbilical. Bulk or buoyancy
• condition of the worksite,

Question 43

The decision on whether or not to use ballast release systems must rest with ?

Answer 43

The diving contractor

Question 44

AODC61 considere the bell ballast release the least desirable option.
True or False

Answer 44

True

Question 45

State the criteria that should be applied in ballast release systems

Answer 45

• At least two independent actions are required to effect release
• no single component failure should result in buoyant ascent of the bell.
• Allowance must be made for the bell tilting either before or during deployment in which case the weights must:
  a) be incapable of inadvertent release e.g. falling off
  b) remain capable of deliberate release.
• The design of new ballast systems should be such that either the secondary system, or any independent system adopted in case of failure of primary and secondary, should be capable of taking the “in-air” weight of the ballast together with appropriate factors for shock load.

Question 46

With whom rest the decision of whether or not to use ballast release systems?

Answer 46

Must rest with the diving contractor after full consideration of all relevant factors.

Question 47

In case of lost bell, which valves should be closed by the diver inside of the bell in an emergency?

Answer 47

• gas sampling to surface for analysis;
• pressure measuring circuits, pneumos;

Circuits such as bell decompression, bell flooding, trunking equalisation, etc., which are not connected to any umbilical circuit cannot be fitted with such devices and must always be closed by hand in an emergency.