MVP 10 Instruction Manual Rev 122706

UNPACKING When received, the instrument should be immediately unpacked and checked to see that all component parts have been received, and that there is no apparent damage. If the MVP-10 was shipped directly to you, and damage due to shipment is found, notify the carrier at once. Only you, the consignee can make a claim against the carrier for damage in shipment. If you received the equipment from a BMD dealer, return it to him for adjustment. The following items are shipped as part of the MVP-10 equipment. Check to assure that all items have been received. • • • • • •

MVP-10 Pediatric Neonatal Ventilator Two (2) Patient Circuits, Catalog #2030 Two (2) supply hoses (1/4" ID x 3/8" OD x 10' long) with attached DISS fittings; one hose for air and one for oxygen. Bracket (for mounting MVP-10 to column) Instruction Manual and Warranty Card Infant Test Lung

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WARRANTY The Model MVP-10 Neonatal Pediatric Ventilator is warranted to be free from defects in workmanship and material for one (1) year from the date of purchase. To insure that its performance is maintained, any necessary repair during the warranty period must be performed by BMD or an authorized agent. The warranty does not apply to the patient circuit and hoses supplied with the instrument. Nor does the warranty cover abuse or misuse of the instrument, or damage due to unauthorized servicing. If service is required, the instrument must be properly packed and shipped pre-paid, directly or through your dealer, to:

Bio-Med Devices, Inc. 61 Soundview Road Guilford, CT 06437

An explanation of the problem should accompany the equipment. Please include your name and telephone number in the paperwork. There is no oral or implied warranty of the instrument's fitness for a particular purpose other than its intended use.

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WARNINGS Clean, dry, regulated gas supplies at 50 ±5 psi (345 ±34.5 kPa) must be used at all times or malfunction may result. Note carefully that the logic (power) gas supply should be 100% oxygen at all times to give the greatest accuracy of the control settings and to assure the most trouble-free operation. If the ventilator is to be used unattended or without remote monitoring, a high/low pressure alarm must be used at all times with the user within visual and/or audible range of this alarm. Recommended monitors for this purpose are Bio-Med Devices’ M-1 or M-10. A TWO-WAY SAFETY RELIEF VALVE is installed internally. This valve opens when pressure in the hose delivering gas to the patient rises above 70 cmH2O ±10 cmH2O or falls below -4 cmH2O. Its purpose is to limit maximum circuit pressure and to allow patient inspiration in the unlikely event of failure of the gas supply. It is meant to allow spontaneous breathing for a short time only until the operator can respond to the disconnect alarm and rectify the supply malfunction. In such a situation, its use in a contaminated environment could be hazardous. The SAFETY RELIEF VALVE must not be removed; and must be maintained with its screened port up and unobstructed. Any HUMIDIFIER used with the MVP-10 must be a "flow-through" type having a low pressure drop. Use of a humidifier with a "bubbler" tube or pressure jet will render the SAFETY RELIEF VALVE ineffective. Do not re-use disposable breathing circuits. Do not use in a MRI room unless the MVP-10 has been built by Bio-Med Devices for such an environment. This will be indicated by a MRI plaque on top of the unit and an “M” at the end of the serial number.

CAUTIONS The BMD MVP-10 Ventilator is intended for use by qualified clinical personnel only. This Instruction Manual should be read before using the equipment. As noted later in the text of this Manual, the MVP-10's time cycle settings are affected by large changes in barometric pressure, flow rates, and gas composition. They are repeatable, however, within 5% under constant conditions. As with any ventilator, periodic blood gas studies should be made to insure proper levels of ventilation. A patient filter should always be used with the MVP-10 to prevent cross contamination and protect the patient. A high/low pressure alarm must be used if the ventilator is to be used unattended. Antistatic or electrically conductive hoses or tubing should not be used.

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I. GENERAL A. INTENDED USE The model MVP-10 Ventilator is for respiratory support of neonatal and pediatric patients both in hospital and during transport. It is intended primarily for use in all applications requiring tidal volumes in the range up to 660 milliliters. It may be used with a wide range of I/E ratios, including inspiratory time greater than expiratory time. WARNING: Do not use in a MRI room unless the MVP-10 has been built by BioMed Devices for such an environment. This will be indicated by a MRI plaque on top of the unit and an “M” at the end of the serial number.

B. MODES OF OPERATION It is a continuous flow Ventilator which may be used in any of the following operation modes: •

• •

Time cycled, with volume or pressure limitation, with or without Positive End Expiratory Pressure (PEEP). -Intermittent Positive Pressure Ventilation (IPPV). -Intermittent Mandatory Ventilation (IMV). Continuous Positive Airway Pressure (CPAP). Continuous Oxygen Administration (COAD) or constant flow.

C. FEATURES • • • • • • • •

Portable: compact and light weight May be hand carried or attached to incubator; used without interruption during transportation; compatible with masks, tents, and endotracheal tubes. Gas Powered: portable pressurized tank or wall outlet, providing 50 psi oxygen or air. Operable in Hazardous Areas: non-electric, no shock hazard, case constantly self-purged. High Reliability: controlled by miniature pneumatic logic elements; fail-safe maximum pressure limits; negligible frictional wear. Very low compliance and dead space factors. Prevention of CO2 build-up by constant flow wash-out. Readily usable with standard accessory humidifier, oxygen blender, oxygen analyzer and pressure alarms.

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D. PERFORMANCE CHARACTERISTICS Direct control is provided for inspiratory and expiratory times, air and oxygen flow rates, and maximum pressure and PEEP or CPAP levels within the patient circuit. Oxygen concentration, respiratory rate, tidal volume, and I/E ratio may also be controlled. •

Oxygen concentration…………... variable, 21% to 100%

•

Respiratory rate…………………. variable, 0 to 120 breaths/min.

•

Tidal volume……………………… variable, 0 to over 660 ml.

•

I/E ratio…………………………… variable

Oxygen concentration is determined by the air and oxygen flow rates indicated by two front panel meters. Flow rates corresponding to a desired oxygen concentration can be determined by use of CHART A. At extremely low flow rates accuracy may be reduced; for more accurate determination an auxiliary oxygen analyzer should be used. Respiratory rate and I/E ratio are determined by INSP. TIME and EXP. TIME control settings. These settings are approximate time reference points which are repeatable within 5%.* For greater accuracy, an external monitoring device may be used. The tidal volume, when operated in a time-cycled mode is the product of total flow and inspiratory time: TIDAL VOLUME (ml) = TOTAL FLOW RATE (ml/sec) X INSPIRATORY TIME (sec) NOTE: Flow rate is not Minute Volume MINUTE VOLUME = TIDAL VOLUME X RESP. RATE It should be noted that the MAX PRESSURE and PEEP/CPAP control settings are affected by flow. When flow is increased, the pressure levels set by these controls will increase somewhat. These changes may be noted on the pressure gauge and the settings readjusted. *At elevations above sea level, the intervals set by the INSP. TIME and EXP. TIME controls are increased due to lower barometric pressure. The difference is about 2½% per 1000' of elevation. With an air supply connected to the POWER OXYGEN inlet fitting, the time intervals are about 10% less than with pure oxygen connected.

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II. DESCRIPTION A. PRINCIPLES OF OPERATION The MVP-10 Ventilator provides continuous flow that maybe time-cycled for automatic ventilation with either volume or pressure limits, and with or without Positive End Expiratory Pressure (PEEP). It may also be used without time cycling to provide continuous flow past the patient at ambient pressure, e.g. Continuous Oxygen Administration (COAD), or at a positive pressure, e.g. Continuous Positive Airway Pressure (CPAP). 1. Time-Cycled Modes: A constant flow is provided past the patient WYE. The expiration valve is cycled so that it is closed for a pre-set time, (TI) and opened for a pre-set time, (TE). When it is opened, gas flows past the WYE at ambient pressure and is vented to atmosphere; when closed, exhaust to atmosphere is prevented and pressure builds up within the circuit, delivering gas to the patient. Gas flow into the system is essentially constant since the source pressure (50 psi) is much greater than the maximum possible circuit pressure (80 cm H2O, or 1.1 psi). An example of this use is for administration of Intermittent Positive Pressure Ventilation (IPPV). a. Volume-limited: The pressure developed in the patient's airway depends upon the total system-patient compliance and the tidal volume being administered. When the MAX. PRESSURE control is set at a pressure above the pressure developed in the circuit, then the automatic ventilation is volume limited, and a constant flow is delivered to the patient. In this condition the tidal volume (Vt) is the product of the total flow rate (VI) and inspiratory time (TI): Vt = T I x VI and minute volume (V) is the product of tidal volume and respiratory rate (f): V = Vt x f Should the patient compliance become less or resistance increase, then the developed pressure could increase up to the MAX. PRESSURE setting. At that point, the pressure in the patient circuit becomes limited and constant. Tidal volume is no longer delivered to the patient; excess gas is vented to atmosphere. b. Pressure-limited: With flow rate and inspiratory time set, the pressure developed in the patient's airway depends upon the system and patient compliances. This pressure is limited by the setting of the MAX. PRESSURE control. While the expiration valve is closed, pressure within the circuit builds up to the MAX. PRESSURE setting. At that point, the valve acts to allow flow past the WYE to atmosphere, while maintaining the airway pressure at the MAX. PRESSURE setting. During the expiratory time, the valve is opened.

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c. Intermittent Mandatory Ventilation (IMV): Respiratory rate is set to allow one or more voluntary breaths between machine-controlled breaths. With sufficient flow, the patient's minute volume and the voluntary tidal volumes are not necessarily limited by the machine parameters. The respiratory rate may be set to support the patient, but less than the anticipated voluntary respiration rate. The lower respiratory rate is normally set by increasing the Expiratory Time. d. Positive End Expiratory Pressure (PEEP): By use of the PEEP/CPAP control, a pressure may be maintained in the patient's airway during the expiratory time in any of the above time-cycled modes (i.e. PEEP), or during a non-cycled mode with continuous flow-past the patient (i.e. CPAP). Adjustment of this control places a controlled pressure on the diaphragm of the expiration valve maintaining the patient circuit at this pressure during the expiratory time. 2. Non-Cycled Modes: A constant flow is provided past the patient WYE, without cycling the expiration valve. a. Continuous Positive Airway Pressure (CPAP): A pre-set pressure is maintained across the expiration valve. Continuous flow is provided past the patient WYE, allowing the patient to inhale from this flow while maintaining the airway at the pre-set constant positive pressure. b. Continuous Flow, or Constant Oxygen Administration (COAD): No pressure is maintained across the open expiration valve (PEEP/CPAP control fully clockwise), and a continuous flow is provided past the patient WYE, allowing the patient to inhale from the flow at ambient pressure. Figure 2 is a flow diagram showing the interconnections within the MVP-10. The expiration valve is controlled by a pneumatic logic circuit which is comprised of four (4) (early models had three (3)) miniature diaphragm devices, four (4) adjustable valves, several fixed flow resistances and a flow accumulator. The diaphragm device is a gas actuated, double-piloted, spring-offset, three- way valve. The entire logic circuit is isolated from the patient circuit by the diaphragm of the expiration valve. Gas flowing into the logic circuit cannot enter the patient circuit, and the exhalation gas cannot enter the logic circuit. A 40-micron filter is incorporated in the input of the logic circuit. The pneumatic switching elements have a rated life of over one-billion switching operations, at rated supply pressure. The logic circuit controls the two time intervals for inspiration and expiration and controls the pressure in the patient circuit.

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FIGURE 2 - FLOW DIAGRAM

AIR FITTING

AIR FLOW CONTROL TWO-WAY RELIEF VALVE

GAS SUPPLIES 50 PSI

O2 FITTING

ADJUSTABLE RELIEF VALVE HUMIDIFIER (OPTIONAL)

PATIENT CONNECTION

O2 FLOW CONTROL

GAUGE CONNECTION

PATIENT AIRWAY

PRESSURE GAUGE

PRESSURE ALARM (OPTIONAL)

PNEUMATIC LOGIC CIRCUIT CYCLE/CPAP SWITCH PEEP/CPAP CONTROL

EXPIRATION VALVE CONNECTION INSP TIME CONTROL

EXP TIME CONTROL

MAX PRESSURE CONTROL

MVP - 10

EXPIRATION VALVE EXHAUST

PATIENT CIRCUIT

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WYE

B. CONTROLS, INDICATORS, AND CONNECTIONS CONTROLS (Front Panel) (1) (2) (3) (4) (5) (6) (7)

CYCLE/CPAP Switch: Selects non-cycling (CPAP) or time-cycled (CYCLE) modes of operation. PEEP/CPAP Control: Sets PEEP level when CYCLE/CPAP switch is set to CYCLE, or CPAP level when set to CPAP. EXP. TIME Control: Sets expiratory time in time- cycled modes. Calibrated in seconds from 0.25 to 2.5 (May be set to 30 seconds for IMV). INSP. TIME Control: Sets inspiratory time in time- cycled modes. Calibrated in seconds from 0.2 to 2.0. MAX. PRESSURE Control: Sets maximum pressure limit in patient circuit. Used to establish a pressure- limited mode. LPM OXYGEN Control: Sets flow rate of oxygen. LPM AIR Control: Sets flow rate of air.

INDICATORS (Front Panel) (8) PRESSURE Gauge: Indicates proximal airway pressure (in cm H2O). (9) OXYGEN Flowmeter: Indicates oxygen flow into system (in liters/minute). (10) AIR Flowmeter: Indicates airflow into system (in liters/minute). CONNECTIONS (Rear Panel) (11) AIR: Connection to pressurized source of clean, dry, oil-free air (50+/- 5 psi). Mates with female DISS air fitting. (12) POWER OXYGEN: Connection to pressurized source of 100% Oxygen, medical grade (50+/-5 psi, 345 ±34.5 kPa). When only one gas supply is used, it must always be connected to POWER OXYGEN connector, since only this line supplies the logic circuit. This mates with female DISS oxygen fitting. (13) GAUGE: Connection to patient WYE (for measurement of pressure in patient circuit). Connect 1/8" ID tubing. (14) PATIENT: Connection to patient circuit at ADJUSTABLE RELIEF VALVE and through HUMIDIFIER (if used). (15) EXP. VALVE: Connection to expiration valve (for control of time-cycling, and CPAP or PEEP or MAX. pressures). Connect 1/8" ID tubing. CAUTION: Antistatic or electrically conductive hoses or tubing should not be used. NOTE: Filtered and dried, regulated gas supplies must be used to ensure reliable operation.

C. SPECIFICATIONS Gas Supplies: Air: Clean, dry, oil-free, 50 ±5 psi (345 ±34.5 kPa) pressure Oxygen: Clean, dry, medical grade, 50 ±5 psi (345 ±34.5 kPa) pressure

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Inspiratory Time: variable 0.2 to 2.0 seconds calibrated* Expiratory Time: variable 0.25 to 2.5 seconds calibrated*; (Variable to 30 seconds, uncalibrated) Oxygen Flow Rate: variable 0 to 10.0 liters/minute meter calibration accuracy: ±3% full scale Air Flow Rate: variable 0 to 10.0 liters/minute, meter calibration accuracy: ±3% full scale Max. Pressure Setting: variable up to 70 ±10 cm H2O Pressure Gauge: -20 to +120 cm H20; ±3% full-scale accuracy Fail-Safe Pressure Limitations: TWO-WAY SAFETY RELIEF VALVE (installed internally): opens at pressures above 70 ±10 cm H2O or below –4 ±1 cm H2O ADJUSTABLE RELIEF VALVE (installed at PATIENT connection): user adjustable to open between a maximum pressure of 80 cm H2O ±10 cmH2O when turned fully clockwise to a minimum of 10 cmH2O ±5 cmH2O when turned fully counterclockwise. PEEP/CPAP Range: variable up to 18 ±3 cm H2O at flow of 6 liters/minute Compliance: less than 0.15 ml/cm H2O max. (with standard patient circuit as supplied, and without inclusion of accessory devices [humidifier]) Dead Space: 0.5 ml maximum Consumption of gas by Logic Circuits: approximately 4 liters/minute at 50 breaths per minute Weight: 2.3 kg. (5 lbs. 2 oz.) Physical Dimensions: 20 x 23 x 7.4 cm (8 x 9 x 3 in.) Storage Temperature:

32° to 122°F (0°to 50°C)

Operating Temperature:

14° to 122°F (-10°to 50°C)

NOTE: Two safety valves are provided to protect the patient from: • asphyxiation due to failure, disconnection or depletion of the gas supply • excessive pressure due to blockage or failure of the expiration valve or hose.

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The TWO-WAY SAFETY RELIEF VALVE is installed internally. It vents pressures above 70 cm H2O ±10 cm H2O. It also opens at negative pressures below -4 cm H2O to allow patient inspiration. (If protection at a lower negative pressure is desired, another more sensitive valve should be added.) The ADJUSTABLE RELIEF VALVE is installed externally and may be adjusted to vent pressures between 70 cm H2O ±10 cmH2O and 10 cm H2O ±5 cmH2O. * INSP. TIME and EXP. TIME control settings are calibrated at sea level and 20o C., using USP oxygen. Large changes of barometric pressure or altitude changes, or use of diluted oxygen will affect time calibration; hence, the settings should be regarded as reference points rather than precise time indicators. However, time settings are repeatable within 5%. Approach time settings in a clockwise direction.

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III. INSTALLATION CONSIDERATIONS A. EQUIPMENT REQUIRED All equipment required for use of the MVP-10 has been supplied with the instrument, except for the gas supply. No special tools are needed. It will be convenient to have available a test lung when setting the ventilator parameters before connecting to a patient. If Bio-Med Devices Infant Test Lung (BMD #1021) is not available, a simple finger cot may be attached to the patient WYE or the WYE may be occluded.

B. SUPPLY GAS The supply gas is normally a pressurized tank(s) or wall source of medical or therapy grade oxygen and/or air. The pressurized tanks should be fitted with regulators adjusted to 50 ±5 psi (345 ±34.5 kPa). No flow restricting device (e.g. flowmeter, throttling valve) can be placed in the supply line. A flow restricting device interferes with the operation of the pneumatic logic and may render the time-cycling inoperative. The MVP-10 will operate with a supply pressure outside of the 50 ±5 psi (345 ±34.5 kPa) range, but accuracy of settings may be impaired. In no case should a supply pressure less than 35 psi (242 kPa) or over 100 psi (690 kPa) be connected to the MVP-10 as it will cause malfunction of the ventilator. The operating time that may be expected from common tank sizes with different flow rates is given in Table B.

C. MOUNTING BRACKET The supplied mounting bracket may be installed on a column.

D. PATIENT CIRCUIT The patient circuit supplied with the MVP-10 incorporates approximate 3-foot lengths of hose between the MVP-10 and (1) the patient WYE and (2) the expiration valve. The hoses are medical grade PVC. CAUTION: Always use a bacterial filter. CAUTION: Do not re-use disposable breathing circuits

E. OPTIONAL EQUIPMENT Other standard equipment which may be used with the MVP-10 at the option of the user include: Oxygen Blender --connected in the supply line to the POWER OXYGEN connection, or both POWER OXYGEN and AIR connectors using BMD "Y" 13

Adapter #2022. Humidifier --connected on "down-stream" side of SAFETY RELIEF VALVE. Only a flow-through humidifier, having a low pressure drop, may be used; otherwise protection provided by the SAFETY RELIEF VALVE is rendered ineffective. A humidifier with a "bubbler" tube or pressure jet should not be used. Pressure Alarms (high and/or low) --T-connected to Gauge line. A Humidifier or Pressure Alarm connection can affect system compliance. Connecting hoses and water level in the Humidifier should be arranged so that system compliance is increased minimally. This means that extra hose lengths should be short, and water level in the Humidifier should be maintained at a high level. Some alarm units affect the volume of gas in the system. The operating characteristics of any auxiliary device should be carefully considered before using it with the MVP-10.

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IV. SET-UP CAUTION: Antistatic or electrically conductive hoses or tubing should not be used.

A. CONNECTION OF GAS SUPPLY Using the MVP-10 front-panel flowmeters for mixing: a)

Connect 50 psi (345 kPa) oxygen supply to rear-panel fitting marked POWER OXYGEN.

b)

Connect 50 psi (345 kPa) air supply to rear-panel fitting marked AIR.

c)

If only a single gas supply is used, it must be connected to the POWER OXYGEN fitting.

d)

If using an external Oxygen Blender, connect 50 psi (345 kPa) Blender output to rear-panel fitting marked POWER OXYGEN, or both POWER OXYGEN and AIR fitting. In either case, it is essential that: • The supplies are 50 psi (345 kPa) sources without flow restricting devices (e.g. flowmeter, valve). • A 50 psi (345 kPa) supply must always be connected to the POWER OXYGEN fitting for proper operation of the pneumatic logic controls. • Hose fittings should be hand tightened to avoid damage to fittings. • The gas supply should be clean and dry (If gas supply contains moisture, add a moisture trap in the supply line to the MVP-10). • When a pressurized supply is not connected to the AIR fitting, the air flowmeter valve should be turned off (fully clockwise).

B. CONNECTION OF PATIENT CIRCUIT a)

Place expiration valve on bracket at side of MVP-10 case.

b)

Connect short length of hose (approx. 1/8" ID x 12" long) between expiration valve control connection and EXP. VALVE fitting at rear of MVP-10. (Always connect this hose first to avoid mistakes.)

c)

Connect small diameter line(1/8" ID) in patient circuit, from WYE, to GAUGE fitting at rear of MVP-10. 15

d)

If a Humidifier is used, connect it to the down-stream side of the SAFETY RELIEF VALVE installed on the PATIENT fitting at the rear of the MVP-10. The large diameter hose (1/4" ID) of the patient circuit is then connected to the Humidifier outlet. Humidification can be provided by a heated flow-through humidifier or artificial nose. If a Humidifier is not used, connect hose of patient circuit directly to ADJUSTABLE RELIEF VALVE.

e)

Connect patient port of WYE to a test lung (Infant Test Lung BMD #1021 or occlude). After selection of parameters and adjustment of controls as described (Sec. V.), observe proper functioning before attaching to the patient. NOTE: Always be certain that the patient circuit hoses are not pinched or twisted by incubator doors, heavy instruments, etc.

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V. SELECTION OF VENTILATION PARAMETERS AND ADJUSTMENT OF CONTROLS A. TIME-CYCLED OPERATION (FOR AUTOMATIC VENTILATION (e.g. IPPV, IMV, with or without PEEP) Determine and note patient requirements for tidal volume, respiratory rate, I/E ratio, and oxygen concentration. Refer to CHART C, to find inspiratory time (TI), expiratory time (TE), and MULTIPLICATION FACTOR to compute flow rate for required tidal volume.

STEP 1 Set MAX. PRESSURE control fully counterclockwise, PEEP/CPAP control fully clockwise. STEP 2 Set INSP. TIME and EXP. TIME controls in a clockwise direction to required times. STEP 3 Determine total flow (VI) required by multiplying the required tidal volume (Vt) by the approximate MULTIPLICATION FACTOR (from CHART C) or by use of slide rule. Set flow rate controls for this total flow. STEP 4 Set CYCLE/CPAP switch in CYCLE position. STEP 5 For oxygen concentration (FIO2) other than air or 100% oxygen, set by adjusting integral flow rate controls, or by adjusting external oxygen blender: a) Using integral flow rate controls, refer to CHART A, which relates oxygen, air, and total flows to oxygen concentration. Set air and oxygen flow for required concentration and total flow determined in Step 3. b) b) Using external oxygen blender, set blender for prescribed concentration, and integral flow rate control for required total flow. (NOTE: Output from oxygen blender must be connected to POWER OXYGEN fitting. If required flow exceeds10 liters/minute, output of blender is connected to both POWER OXYGEN and AIR fittings, using a Y adapter (not supplied). BMD accessory #2022.

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EXAMPLE: Prescribed Parameters: Tidal Volume Respiratory Rate I/E Ratio Oxygen Concentration Machine Compliance Factor

= 10 ml = 40 breaths/minute = 1:2 = 60% = 0.5 ml/cm H2O

From CHART C: Respiratory Cycle Inspiratory Time Expiratory Time Multiplication Factor

= 1.5 secs. = 0.5 secs. = 1.0 secs. = 120

Total Flow (VI) = Tidal Volume (Vt) x Mult. Factor 10 ml x 120 = 1200 ml/min (1.2 liter/min) or Total Flow (VI) =

Tidal Volume (Vt) Inspiratory Time (TI)

Total Flow (VI) =

10 ml 0.5 sec

Total Flow (VI) = 20 ml/sec (1.2 liters/min.

From CHART A: For 60% oxygen concentration Oxygen Flow (VIO2) = 600 ml/min (0.6 liters/min) Air Flow (VAir) = 600 ml/min (0.6 liters/min) STEP 6

Attach test lung to WYE and observe proper cycling. If operation is normal, remove test lung and determine compliance of system as follows: a) Plug WYE port, which connects to patient airway. b) With parameters set for prescribed tidal volume, observe maximum reading on pressure gauge during inspiratory time. If gauge reading is over 70 cm H2O, temporarily reduce tidal volume by lowering flow rate and/or inspiratory time so that 18

gauge reading is less than 70 cm H2O. c) Compliance factor (CM) of system, without patient connected, is:

CM =

Tidal Volume (Vt) Pressure Gauge Reading (P) Note: Vt= VI x TI

The compliance factor of the MVP-10 with patient circuit is approximately 0.12 ml/cm H2O. With a humidifier connected, it is between 0.2 and 0.5 ml/cm H2O, depending upon the humidifier, its water level and connecting hoses. A compliance factor of 0.5 ml/cm H2O means that 0.5 ml of gas is stored in the patient circuit and humidifier for each cm H2O of pressure during the respiratory cycle, and does not go to the patient. In the example in STEP 5, assume that the pressure gauge reaches 10 cm H2O during the cycle. This would mean that 10 x 0.5 or 5 ml is stored in the circuit. The apparent tidal volume is 10 ml, but only a 5 ml tidal volume would be delivered to the patient. STEP 7

Compensate for the compliance of the system by increasing total flow. In the previous example, 5 ml must be supplied for the compliance in the system, as well as the prescribed 10 ml tidal volume for the patient. Therefore, adjust flow rate to supply a 15 ml tidal volume: Adjusted Flow = 15 ml x 120 = 1800 ml/min (1.8 liters/min) The pressure gauge reading will increase a little, because of the greater volume in the system, to say, 12 cm H2O. Compliance volume would now be 12 x 0.5, or 6 ml, and a tidal volume of 9 ml would be supplied to the patient. To more closely obtain the prescribed tidal volume, a second compensatory increase in flow is necessary. With flow increased to 2 liters/min, or about 33 ml/sec., the pressure gauge may indicate 13 cmH2O. The volume per cycle would now be 33 ml/sec. x 0.5 sec., or 16.5 ml. The compliance volume would be 13 x 0.5, or 6.5 ml, and the prescribed tidal volume of 10 ml would be supplied to the patient.

STEP 8

Volume-limited or pressure-limited operation may be established as follows: a) For Volume-limited operation - Set the MAX. PRESSURE control fully counterclockwise. 19

With patient airway connected to WYE, observe maximum pressure during cycle. Detach patient airway from WYE and block patient port of WYE. Adjust MAX. PRESSURE control so cycle pressure is 5 to 10 cm H2O higher than max. pressure with patient connected. Re-connect the patient airway to WYE. The MVP-10 will now be limited to the tidal volume determined by the flowmeter and INSP. TIME settings, and will be limited to a maximum pressure in case resistance or compliance characteristics change. b)

For Pressure-limited operation - Observe maximum pressure during inspiratory time. Adjust ADJUSTABLE RELIEF VALVE (pre-set at factory to open at 70-80 cmH2O depending on flow) by occluding patient port of WYE and turning knurled adjusting cap counterclockwise until valve relieves pressure at 5 to 10 cmH2O above desired pressure limit. Use lock ring to secure adjusting cap. Adjust MAX. PRESSURE control until the desired pressure limit is seen during inspiration. Note that the MAX. PRESSURE level is somewhat affected by the flow rate. It should be set with the particular flow rate used. The MVP-10 will now be limited to the pressure set. When operating in this mode, the exact Tidal Volume is unknown, since gas is vented to the atmosphere as soon as the pre-set pressure limit is reached during each inspiration. Calculation of and compensation for compliance losses are unnecessary.

STEP 9

If PEEP is to be used, set the desired level using the PEEP/CPAP control. Adjust control until the pressure gauge indicates the desired level during the expiratory time. Note that the PEEP level is somewhat sensitive to flow rate. The PEEP control should be set with the flow rate used.

STEP 10 For Intermittent Mandatory Ventilation (IMV) determine prescribed tidal volume, inspiratory time, and rate of automatic cycles. Calculate flow rate: Flow (VI) =

Tidal Volume (Vt) Inspiratory Time (TI) 20