Dräger Narkomed 2B Assembly instructions

North
A
merica
n
Dräger
Operator’s Instruction Manual
Part Number: 4113918-002
Rev: B
Date: 20 November 1998
© 1998 N.A.D., Inc.
Narkomed 2B
Anesthesia System

Narkomed 2B
Operator’s Instruction Manual
Table of Contents
Section 1: Introduction
Operator’s Responsibility for Patient Safety ................................... 1-1
Limitation of Liability ................................................... 1-2
Restriction .......................................................... 1-2
Symbol Definition ..................................................... 1-2
How This Manual Is Organized ........................................... 1-3
Conventions Used in This Manual ......................................... 1-4
General Warnings and Cautions ........................................... 1-4
Recommendations ..................................................... 1-5
Section 2: General Description
Overview ........................................................... 2-1
Gas Delivery System ................................................... 2-1
Vaporizers ......................................................... 2-11
Absorber .......................................................... 2-12
Bain Circuit Adapters .................................................. 2-15
Scavenger Systems ................................................... 2-17
AV2+ Ventilator ...................................................... 2-19
Main Switch Panel .................................................... 2-20
Power Supply System ................................................. 2-22
System Interface Panel ................................................ 2-24
Monitoring System .................................................... 2-25
Alarm System ....................................................... 2-26
Manual Sphygmomanometer ............................................ 2-27
O.R. Data Manager®.................................................. 2-28
Section 3: Daily Checkout
Daily Checkout Procedure ............................................... 3-1
Section 4: Preuse Checkout
Preuse Checkout Procedure ............................................. 4-1
Section 5: Operation
Gas Delivery System
Overview .................................................... 5-1-1
Connecting the Pipeline Gas Supply ................................. 5-1-1
Connecting the Gas Cylinders ..................................... 5-1-2
Connecting the Fresh Gas Hose .................................... 5-1-4
Adjusting the Gas Flow .......................................... 5-1-4
Using the Oxygen Flush .......................................... 5-1-4
i

Narkomed 2B
Operator’s Instruction Manual
Table of Contents
Vaporizer
Overview .................................................... 5-2-1
Filling Systems ................................................ 5-2-1
North American Dräger Exclusion System ............................. 5-2-2
Operating the Vaporizers ......................................... 5-2-3
Filling the Vaporizer ............................................. 5-2-4
Filling the Vaporizer During a Case .................................. 5-2-5
Draining the Vaporizer .......................................... 5-2-11
Absorber System
REFER TO SEPARATE MANUAL .................................. 5-3-1
Bain Circuit Adapter
REFER TO SEPARATE MANUAL .................................. 5-4-1
Open Reservoir Scavenger
Overview .................................................... 5-5-1
Connecting the Open Reservoir Scavenger System ...................... 5-5-2
Operating the Open Reservoir Scavenger System ....................... 5-5-3
Scavenger Interface for Passive Systems
Overview .................................................... 5-6-1
Operating the Scavenger Interface for Non-active Systems ................ 5-6-2
Main Switch Panel
Overview .................................................... 5-7-1
System Power Switch ........................................... 5-7-1
Testing the Battery ............................................. 5-7-2
AV2+ Anesthesia Ventilator
Overview .................................................... 5-8-1
Activating the Ventilator .......................................... 5-8-2
Adjusting the Tidal Volume ........................................ 5-8-4
Setting the Respiratory Frequency .................................. 5-8-4
Setting the Inspiratory/Expiratory (I:E) Phase Time Ratio .................. 5-8-5
Setting the Inspiratory Flow Rate ................................... 5-8-5
Setting the Inspiratory Pressure Limit ................................ 5-8-5
Problem Resolution ............................................. 5-8-6
Monitoring System
Overview .................................................... 5-9-1
Power-On Screen .............................................. 5-9-1
Monitor Screens and Controls ..................................... 5-9-2
Configuring the Anesthesia Machine ................................. 5-9-4
Controlling Continuous Audible Alarms ............................... 5-9-6
Working with Trace Data ......................................... 5-9-7
Working with Trend Data ......................................... 5-9-8
Working with Numerical Data ..................................... 5-9-10
ii

Narkomed 2B
Operator’s Instruction Manual
Table of Contents
Oxygen Monitoring
Overview ................................................... 5-10-1
Monitor Displays .............................................. 5-10-2
Monitor Controls .............................................. 5-10-3
Setting Alarm Limits ............................................ 5-10-4
Calibrating the Oxygen Sensor .................................... 5-10-5
Unsuccessful Calibration ........................................ 5-10-7
Oxygen Alarm Messages ........................................ 5-10-9
Low Oxygen Supply Whistle ..................................... 5-10-10
Problem Resolution ........................................... 5-10-11
Respiratory Volume Monitoring
Overview ................................................... 5-11-1
Monitor Displays .............................................. 5-11-2
Monitor Controls .............................................. 5-11-3
Setting the Minute Volume Low Alarm Limit ........................... 5-11-4
Controlling Volume Alarms ....................................... 5-11-4
Respiratory Volume Alarm Messages ............................... 5-11-5
Problem Resolution ............................................ 5-11-7
Breathing Pressure Monitoring
Overview ................................................... 5-12-1
Choice of Breathing Pressure Monitoring Location ...................... 5-12-1
Installing the Breathing Pressure Pilot Line ........................... 5-12-2
Monitor Displays .............................................. 5-12-4
Monitor Controls .............................................. 5-12-6
Setting the Pressure High Alarm Limit ............................... 5-12-6
Setting the Threshold Pressure Alarm Limit ........................... 5-12-7
Controlling the Apnea Alarm ...................................... 5-12-9
Breathing Pressure Alarm Messages .............................. 5-12-10
Problem Resolution ........................................... 5-12-11
Manual Sphygmomanometer
Overview ................................................... 5-13-1
Selecting a Blood Pressure Cuff ................................... 5-13-2
Connecting the Cuff ............................................ 5-13-2
Placing the Cuff ............................................... 5-13-3
Section 6: Cleaning and Routine Maintenance
Overview ........................................................... 6-1
Routine Maintenance ................................................... 6-1
Removing Parts for Cleaning and Disinfection ................................. 6-7
Disassembling Parts for Cleaning and Disinfection ............................. 6-10
General Guidelines for Cleaning and Disinfection ............................. 6-12
Reassembly Instructions ............................................... 6-19
iii

Narkomed 2B
Operator’s Instruction Manual
Table of Contents
Section 7: Specifications
General ............................................................ 7-1
Environmental ........................................................ 7-1
Electrical ........................................................... 7-1
Gas Delivery System ................................................... 7-2
Vaporizers .......................................................... 7-3
Ventilator ........................................................... 7-3
Absorber System ...................................................... 7-3
Oxygen Monitoring .................................................... 7-4
Breathing Pressure Monitoring ............................................ 7-4
Respiratory Volume Monitoring ............................................ 7-4
Serial Interface ....................................................... 7-5
Appendix - Spare and Replacement Parts ........................................ A-1
Index ..................................................................... I-1
iv

Section 1
Introduction
Operator’s
Responsibility for
Patient Safety
North American Dräger anesthesia products are designed to provide the
greatest degree of patient safety that is practically and technologically
feasible. The design of the equipment, the accompanying literature, and
the labeling on the equipment take into consideration that the purchase
and use of the equipment are restricted to trained professionals, and
that certain inherent characteristics of the equipment are known to the
trained operator. Instructions, warnings, and caution statements are
limited, therefore, to the specifics of the North American Dräger design.
This publication excludes references to hazards which are obvious to a
medical professional, to the consequences of product misuse, and to
potentially adverse effects in patients with abnormal conditions. Product
modification or misuse can be dangerous. North American Dräger
disclaims all liability for the consequences of product alterations or
modifications, as well as for the consequences which might result from
the combination of North American Dräger products with products
supplied by other manufacturers if such a combination is not endorsed
by North American Dräger.
The operator of the anesthesia system must recognize that the means of
monitoring and discovering hazardous conditions are specific to the
composition of the system and the various components of the system. It
is the operator, and not the various manufacturers or suppliers of
components, who has control over the final composition and
arrangement of the anesthesia system used in the operating room.
Therefore, the responsibility for choosing the appropriate safety
monitoring devices rests with the operator and user of the equipment.
Patient safety may be achieved through a variety of different means
depending on the institutional procedures, the preference of the
operator, and the application of the system. These means range from
electronic surveillance of equipment performance and patient condition
to simple, direct contact between operator and patient (direct
observation of clinical signs). The responsibility for the selection of the
best level of patient monitoring belongs solely to the equipment operator.
To this extent, the manufacturer, North American Dräger, disclaims
responsibility for the adequacy of the monitoring package selected for
use with the anesthesia system. However, North American Dräger is
available for consultation to discuss monitoring options for different
applications.
1-1

Section 1
Introduction
Limitation of
Liability
North American Dräger’s liability, whether arising from or related to the
manufacture and sale of the products, their installation, demonstration,
sales representation, use, performance, or otherwise, including any
liability based upon North American Dräger’s product warranty, is
subject to and limited to the exclusive terms of North American Dräger’s
limited warranty, whether based upon breach of warranty or any other
cause of action whatsoever, regardless of any fault attributable to North
American Dräger and regardless of the form of action (including, without
limitation, breach of warranty, negligence, strict liability, or otherwise).
North American Dräger shall in no event be liable for any
special, incidental, or consequential damages (including loss of
profits) whether or not foreseeable and even if North American
Dräger has been advised of the possibility of such loss or
damage. North American Dräger disclaims any liability arising
from a combination of its product with products from another
manufacturer if the combination has not been endorsed by North
American Dräger. Buyer understands that the remedies noted in
North American Dräger’s limited warranty are its sole and
exclusive remedies.
Furthermore, buyer acknowledges that the consideration for the
products, equipment, and parts sold reflects the allocation of
risk and the limitations of liability referenced herein.
Restriction Federal law restricts this device to sale by, or on the order of, a
physician.
Symbol Definition The following symbols appear on the label on the back of the Narkomed
2B and are defined below.
CAUTION: Refer to accompanying documents before
operating equipment.
ATTENTION: Consulter les documents ci-joints avant de
faire fonctionner l’apparail.
CAUTION: Risk of electric shock, do not remove cover.
Refer servicing to a North American Dräger
qualified technical service representative.
ATTENTION: Risque de choc electrique, ne pas enlever le
couvercle. Ne faire reparer que par un
representant technique autorise de North
American Dräger.
Degree of protection against electric shock: Type B.
Protection contre le risque de choc electrique: Type B.
1-2

Section 1
Introduction
These additional symbols are used on other locations of the Narkomed
2B to provide quick and easy recognition of product functions.
OXYGEN CONCENTRATION
BREATHING PRESSURE
BREATHING VOLUME
AUDIBLE ALARM DISABLE
AUDIBLE ALARM ENABLE
THRESHOLD PRESSURE ALARM LIMIT
How This Manual Is
Organized
All users of the Narkomed 2B must read this manual completely before
using the machine. In order to make this document more convenient for
future reference, it has been divided into several independent sections.
“Section2-General Description”provides a summary of Narkomed 2B
features and functions.
“Section3-Daily Checkout”contains the checkout procedures that must
done on a daily basis.
“Section 4 -Preuse Checkout”contains the checkout procedures to be
performed between successive cases.
“Section5-Operation”provides detailed instructions on the use and
operation of each functional component of the system.
“Section6-Cleaning and Routine Maintenance”provides cleaning,
maintenance, and replacement procedures.
“Section 7 - Specifications”contains the specifications for all system
components.
1-3

Section 1
Introduction
Conventions Used
in This Manual
This manual has been set up with several conventions to help organize
the information contained in it. Please read about these conventions
carefully so that you understand their significance in the manual.
Typefaces Different typefaces are used throughout the manual to differentiate
between narrative information and machine messages and labels.
Warnings and
Cautions
All parts of this manual contain warning and caution statements about
the Narkomed 2B.
•Warning statements give important information that, if ignored,
could lead directly to a patient’s injury.
•Caution statements give important information that, if ignored, could
lead directly to equipment damage and, indirectly, to a patient’s
injury.
General Warnings
and Cautions
The following list of warnings and cautions apply to general operation
and maintenance of the Narkomed 2B. Warnings and cautions about
installing and operating specific parts appear with those topics.
WARNING: Any person involved with the setup, operation, or
maintenance of the Narkomed 2B anesthesia system must
be thoroughly familiar with this instruction manual.
WARNING: This anesthesia system will not respond automatically to
certain changes in patient condition, operator error, or
failure of components. The system is designed to be
operated under the constant surveillance and control of a
qualified operator.
WARNING: No third-party components shall be attached to the
anesthesia machine, ventilator, or breathing system
(except for certain approved exceptions). Contact the North
American Dräger technical service department for further
information.
WARNING: When moving the anesthesia machine, remove all monitors
and equipment from the top shelf, remove the absorber
system, and use only the machine handles or push/pull
bars. The anesthesia machine should only be moved by
people who are physically capable of handling its weight.
North American Dräger recommends that two people move
the anesthesia machine to aid in maneuverability. Exercise
special care so that the machine does not tip when moving
up or down inclines, around corners, and across thresholds
(for example, in door frames and elevators). Do not
attempt to pull the machine over any hoses, cords, or other
obstacles on the floor.
1-4

Section 1
Introduction
CAUTION: Although the Narkomed 2B is designed to minimize the
effects of ambient radio-frequency interference, machine
functions may be adversely affected by the operation of
electrosurgical equipment or short wave or microwave
diathermy equipment in the vicinity.
CAUTION: Communications with external equipment may be
temporarily affected by electromagnetic interference due to
the use of electrosurgical equipment.
CAUTION: Do not place sensitive electronic equipment on or adjacent
to the display screen.
CAUTION: Do not place more than 100 pounds on top of the
Narkomed 2B monitor housing.
Recommendations In the interest of patient safety, North American Dräger strongly
advocates the use of an oxygen analyzer, pressure monitor, and either a
volume monitor or an end-tidal CO2monitor in the breathing circuit at
all times.
Because of the sophisticated nature of North American Dräger
anesthesia equipment and its critical importance in the operating room
setting, it is highly recommended that only appropriately trained and
experienced professionals be permitted to service and maintain this
equipment. Please contact North American Dräger’s Technical Service
Department at [phone] for service of this equipment.
North American Dräger also recommends that its anesthesia equipment
be serviced at three-month intervals. Periodic Manufacturer’s Service
Agreements are available for equipment manufactured by North
American Dräger. For further information concerning these agreements,
contact the North American Dräger Technical Service Department at
[phone].
1-5

Section 2
General Description
Overview The Narkomed®2B is a continuous flow anesthesia system. All
Narkomed 2B machines are equipped with a monitoring system and
pneumatic circuitry for delivering gases and anesthetic vapor. A front
view of the Narkomed 2B is shown in the figure below.
MONITOR
CONTROL
KEYS
MANUAL
SPHYGMOMANOMETER
(OPTIONAL)
ALARM
DISPLAY
DATA
DISPLAY
BREATHING SYSTEM
SENSOR INTERFACE
PANEL
BOOM ARM
(OPTIONAL)
VENTILATOR
BELLOWS
VENTILATOR
O2 FLUSH
VAPORIZERS
(OPTIONAL)
AUXILIARY OXYGEN
FLOWMETER
(OPTIONAL)
MAIN SWITCH
PANEL
FLOWMETER
BANK
FRESH GAS
OUTLET
OP20001
OPEN RESERVOIR
SCAVENGER
Gas Delivery
System
The pneumatic system can simultaneously deliver up to four gases and
one anesthetic agent (from a selection of up to three). Oxygen and
nitrous oxide are standard on all Narkomed 2B machines. Optional
gases are air, carbon dioxide, and oxygen-helium. Gas is supplied to the
system through pipelines and cylinders. Connections for oxygen and
nitrous oxide are standard on all machines, and a pipeline connection for
air is also available. Gas cylinder yokes are available for up to two
oxygen cylinders and two nitrous oxide cylinders, plus one additional
cylinder for a third gas.
2-1

Section 2
General Description
Color Coding Each connection, valve, gauge, and flowmeter is labeled and color-coded
for the appropriate gas, as shown in the table below.
GAS SYSTEM COLOR CODING
GAS MARKING USA ISO Germany
Air AIR Yellow Black/White
Checkered
Yellow
Carbon Dioxide CO2Gray Gray Black
Nitrous Oxide N2O Blue Blue Gray
Oxygen O2Green White Blue
Oxygen-Helium O2-He Brown/Green
Diagonal Stripes
Brown/White
Diagonal Stripes
N/A
Gas Entry Via
Pipeline
Gas from the hospital pipelines enters the Narkomed 2B through hoses
connected to indexed pipeline inlets located on the side of the flowmeter
housing. The indexed connector system reduces the risk of delivering the
wrong gas to a patient by preventing incorrect connection of gas pipes.
The inlets include check valves, which prevent back flow leakage into
the atmosphere (when supply hoses are not connected) or into the
attached supply hoses (when reserve cylinders are in use). Each pipeline
connection is equipped with a filter to prevent foreign material from
entering the internal gas piping of the Narkomed 2B. Pipeline gases
should be supplied at 50–55 psi.
Pipeline Pressure
Gauges
The anesthesia machine includes pipeline pressure gauges for oxygen
and nitrous oxide. On machines equipped with air, a pipeline pressure
gauge for air is also included. The gauges are located directly below their
corresponding flowmeters and flow control valves, and are labeled and
color-coded for their respective gases. Concentric scales in psi and kPa
indicate the pipeline supply pressure. A typical pressure gauge and
flowmeter arrangement is shown in the following figure.
2-2

Section 2
General Description
10
9
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3
2
1
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9
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9
10 1000
1000
900
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300
400
500
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900
1000
COARSE FLOW
TUBE (l/min)
FINE FLOW
TUBE (ml/min)
INDICATOR
FLOATS
FLOWMETER
GUARD KNOB
FLOW CONTROL
VALVE
PIPELINE
PRESSURE
GAUGE
CYLINDER
PRESSURE
GAUGE
OP10006
THREE-GAS FLOWMETER
AND PRESSURE GAUGE ASSEMBLY
PIPELINE
CYLI NDER
PIPELINE
CYLI NDER
AIR O 2 N 2 O
PIPELINE
CYLINDER
N 2 O
AIR O
2
When the machine is connected to an active pipeline supply, each gauge
should indicate a steady pressure of 50–55 psi. A deviation from this
range indicates an improperly adjusted pipeline supply, which may
adversely affect the operation of the anesthesia machine. A fluctuating
pipeline supply pressure, for example, would cause a corresponding
fluctuation of the flow of gas delivered from that pipeline. An excessively
low pipeline pressure may activate the corresponding reserve cylinder
and deplete its contents (if the reserve cylinder valve was left in the
open position).
CAUTION: To ensure that gas supplies are at adequate pressure,
pipeline pressure gauges should indicate steady pressures
of 50–55 psi.
2-3

Section 2
General Description
Gas Entry Via
Cylinder Yokes
The Narkomed 2B can be equipped with a maximum of two oxygen and
two nitrous oxide cylinder hanger yokes. An additional yoke for an
optional third gas is also available. To prevent a cylinder from being
improperly connected, the yokes are labeled, color-coded, and keyed for
gas-specific cylinders using the pin-indexed safety system.
A filter within each yoke prevents foreign material from entering the
internal gas piping of the Narkomed 2B. A check valve in each yoke
prevents leakage into the atmosphere if the cylinder is not mounted on
the yoke. When the machine is configured with two yokes for the same
gas, the check valve prevents movement of gas from one cylinder to the
other. If a cylinder is not mounted to a yoke, the attached yoke plug
should be placed between the yoke handle’s threaded bolt and the yoke’s
gas inlet.
When attaching a cylinder, make sure that only one washer is installed
between the cylinder and the yoke gas inlet. Using multiple washers
may compromise the pin-indexed safety system. Be sure to verify the
integrity of both index pins whenever you install a new cylinder.
WARNING: Check cylinder yokes for the presence of two index pins
each time you attach a cylinder to the machine. Use only
one cylinder gasket per yoke; using more than one gasket
could cause leakage of the cylinder gas and compromise
the pin-indexed safety system.
Cylinders attached to the hanger yokes must contain gas at the
recommended pressures outlined in the table below. (Indicated pressures
are of E-size cylinders at 70°F, or 21°C.) Cylinders measuring less than
the minimum recommended pressure (PSI - MIN) should be replaced
with new, full cylinders.
GAS PSI - FULL*PSI - MIN
Air 1900 1000
Carbon Dioxide 838 600
Oxygen-Helium 1900 1000
Nitrous Oxide 745 600
Oxygen 1900 1000
* typical full load
2-4

Section 2
General Description
Cylinder Pressure
Gauges
Each cylinder gas circuit has a cylinder pressure gauge, located at the
bottom of the flowmeter panel on the front of the machine (see the
Flowmeter and Pressure Gauge Assembly figure earlier in this section.)
Each gauge is labeled and color-coded for its respective gas. When a
cylinder’s valve is open, its pressure gauge indicates the gas pressure in
the cylinder. The dial is marked with concentric scales for psi and kPa.
If two reserve cylinders of the same gas are open at the same time, the
gauge indicates the pressure in the cylinder having the higher pressure.
For nonliquefied gases (oxygen, air, oxygen-helium), the indicated
pressure is proportional to the gas content of the cylinder. For liquefied
gases (nitrous oxide, carbon dioxide), the gauge indicates the vapor
pressure of the liquefied gas in the cylinder. This pressure remains
constant until all of the liquid in the cylinder has vaporized. When the
liquid has vaporized, the cylinder pressure decreases proportionally as
gas is removed from the cylinder.
Oxygen Failure
Protection Device
(OFPD)
An oxygen failure protection device (OFPD) is a pneumatically operated
valve that protects the patient in the event of partial or complete loss of
oxygen pressure. Each gas circuit in the anesthesia machine, except the
oxygen circuit, is controlled by one of these valves. These valves, in turn,
are controlled by the gas pressure in the oxygen supply line. When
oxygen pressure is adequate, the valves remain open for an unrestricted
gas flow. Loss of oxgyen pressure causes the valves to close to a degree
that is proportional to the loss. The result is a restriction or shut down
of the flow of all gases except oxygen.
Reductions of gas flow are indicated on the flowmeters. In addition, if
the oxygen supply pressure drops below approximately 37 psi, an oxygen
supply pressure alarm is activated, causing the following events to occur:
•The Caution message LO O2SUPPLY appears on the central
alarm display.
•The red O2SUPPLY PRESSURE indicator on the main switch
panel lights.
•An intermittent audible alarm sounds.
•A 7-second whistle may sound, depending on the machine’s
configuration.
NOTE: When one source of oxygen pressure (either pipeline or
reserve cylinders) fails, but the other source is able to
maintain proper pressure within the machine’s oxygen supply
lines, the oxygen supply pressure alarm is not activated.
2-5

Section 2
General Description
Flowmeters Flowmeters, located directly above their corresponding flow control
valves, display the delivered flow rate of each gas in the fresh gas
mixture. Dual flowmeter tubes (fine and coarse) are used in tandem for
oxygen, nitrous oxide, and air (if provided). When other gases are
supplied, single flowmeter tubes are used. All flowmeters are labeled at
each end of the flowtube. A typical flowmeter arrangement is shown in
the Flowmeter and Pressure Gauge Assembly figure earlier in this
section.
Each flowmeter has a float indicator. To determine the flow rate, read
the flowmeter scale at the center of the float.
Low-Flow
Flowmeters
(Optional)
For low-flow anesthesia, the Narkomed 2B can be configured with low-
flow, dual-tube flowmeters for oxygen and nitrous oxide. These
flowmeters function the same way as the standard dual-tube flowmeters,
but they are calibrated to provide greater resolution for low-flow
anesthesia.
Minimum Oxygen
Flow
The oxygen dispensing system incorporates a calibrated bypass flow of
150 ±50 ml/min (at 50 psi pipeline pressure), which delivers this volume
of oxygen even if the oxygen flow control valve is fully closed.
Flow Control
Valves
A needle valve is located below the fine flowmeter tube for each gas.
This valve is used to adjust the flow of gas. Turning the valve knob
counterclockwise increases flow; turning the knob clockwise decreases
flow. A zero stop prevents damage to the flow control valve seats. If
necessary, a North American Dräger qualified technical service
representative can readjust the stop.
Each flow control knob is identified by its color code and chemical
symbol. The oxygen flow control valve is also touch-coded with a deeply
fluted knob.
CAUTION: The flow of oxygen cannot be completely shut off (see
“Minimum Oxygen Flow”earlier in this section). Do not
force the oxygen flow control knob in an effort to shut off
the minimum flow; forcing the knob can damage the valve
seat.
2-6

Section 2
General Description
Oxygen Flush A manually operated, self-closing oxygen flush valve is located on the
front of the machine. A bezel is mounted around the pushbutton in order
to prevent accidental engagement. The valve, when actuated, delivers an
unmetered oxygen flow of approximately 55 l/min directly to the
Narkomed 2B’s fresh gas common outlet. The SYSTEM POWER switch
does not have to be in the ON position to use the oxygen flush.
Oxygen Ratio
Controller (ORC)
The ORC is a pneumatic oxygen/nitrous oxide interlock system. It
maintains a fresh gas oxygen concentration of 25 ±4% and permits
independent control of the oxygen and nitrous oxide flows.
The ORC proportionally limits the nitrous oxide flow whenever the
selected oxygen and nitrous oxide flow control valve settings would
otherwise result in a hypoxic fresh gas mixture. For example, if you open
the nitrous oxide flow control valve excessively without making a
corresponding increase in the oxygen flow control valve setting, the flow
of nitrous oxide will not increase even though its flow control valve
setting has been greatly increased. Similarly, if you decrease the oxygen
flow without also decreasing the nitrous oxide flow, the nitrous oxide
flow will automatically drop in proportion to the oxygen flow.
WARNING: In circle systems the gas mixture in the patient circuit is
not necessarily the same as that in the fresh gas flow. This
is particularly true at low fresh gas flow rates when the
patient rebreathes a significant portion of previously
exhaled gases. It is important that the gas mixture in the
patient circuit be monitored, and that the fresh gas flow be
adjusted to meet the requirements of the patient as well as
to compensate for any patient uptake, system leakage, or
gas withdrawn through sample lines and not returned.
WARNING: The ORC interlocks only the flows of oxygen and nitrous
oxide. Hypoxic fresh gas concentrations are possible if
carbon dioxide is used as an additional gas.
2-7

Section 2
General Description
Fresh Gas Outlet The fresh gas outlet delivers the fresh gas mixture (consisting of oxygen,
nitrous oxide, optional gases, and vapors of a liquid anesthetic) to the
patient breathing system. It is located on the front of the anesthesia
machine.
The outlet’s 15 mm cylindrical female fitting is designed to accept a
15 mm male fitting on the absorber fresh gas hose. The male fitting
slides into a retaining slot in the spring-loaded safety locking bar to
prevent inadvertent disconnection of the fresh gas hose. The 15 mm
male fitting on the fresh gas hose is unique to North American Dräger
design, and cannot be replaced by a hose from any other manufacturer.
O2 FLUSH
CONTROL
HANDLE
FRESH GAS
LOCKING BAR
(
EXTENDED POSITION
)
RELEASE TO
LOCK
TABLETOP
FRESH GAS
OUTLET
FRESH
GAS
HOSE
OP10011
2-8