COMBINATION CPAP AND RESUSCITATION SYSTEMS AND METHODS
BACKGROUND OF THE INVENTION
Field of the Invention
[0001] The present invention relates to breathing assistance systems and
methods. In particular, the present invention relates to systems and methods for
providing positive airway pressure therapy or resuscitation therapy to an infant.
Description of the Related Art
[0002] Under certain circumstances it is necessary or desirable to provide
breathing assistance to a patient under respiratory distress. For example, breathing
assistance is often a necessary therapy to treat respiratory distress syndrome (RDS) in
infants, which can also be referred to as neonatal respiratory distress syndrome or
respiratory distress syndrome of newborn. The breathing assistance provided is often in
the form of providing breathing gases at a positive pressure, or a pressure somewhat
greater than atmospheric pressure. Such treatments may be referred to in general as
positive airway pressure (PAP) therapy. Often, the positive pressure is provided by a
continuous flow of breathing gases, which is referred to as continuous positive airway
pressure (CPAP) therapy. Infants on CPAP therapy to treat respiratory distress syndrome
may also be likely to stop breathing and require resuscitation therapy.
SUMMARY OF THE INVENTION
[0003] A preferred embodiment is a combination positive airway pressure and
resuscitation system and, preferably, a continuous positive airway pressure and
resuscitation system, as well as methods relating to the set-up and use of such a system.
Conventionally, in response to RDS, an infant is treated with a PAP system for an
extended period of time. If necessary, a separate resuscitation system is utilized to
provide resuscitation. Subsequently, the use of the PAP system is resumed. This method
results in inefficiencies caused by the switchover from one system to the other. In
particular, the patient interface is usually switched when going from one system to the
other, which can be time consuming and disruptive to the infant. The preferred systems
and methods allow PAP or CPAP therapy for extended periods, along with intermittent
resuscitation, in a quick and efficient manner and without requiring the patient interface
to be changed.
[0004] A preferred embodiment involves a combination infant positive airway
pressure and resuscitation system, including an integrated inspiratory pressure device
comprising a resuscitator and a humidifier. The resuscitator is capable of regulating a
flow of breathing gas to a desired peak inspiration pressure. The humidifier humidifies
the flow of breathing gas. An expiratory pressure device is configured to receive
expiratory gases from an expiratory circuit and regulate the expiratory gases to a positive
end expiration pressure. An occlusion device is within the expiratory circuit upstream
from the expiratory pressure device and is configured to permit occlusion of the
expiratory circuit at desired times such that the pressure within the inspiratory circuit rises
to the peak inspiration pressure of the resuscitator.
[0004] In some embodiments of the above-described system, the resuscitator
is separable from the humidifier. The resuscitator can be integrated with a first housing
and the humidifier can be integrated with a second housing. Some of the above-described
system can include a flow generator that generates the flow of breathing gas. The flow
generator can be integrated with the second housing.
[0005] A preferred embodiment involves a combination infant positive airway
pressure and resuscitation system. The system includes an inspiratory pressure device
that outputs a flow of breathing gas at a desired peak inspiration pressure to an inspiratory
circuit. A patient interface receives the flow of breathing gas from the inspiratory circuit,
wherein the patient interface is configured to deliver the flow of breathing gas to an infant
patient and receive expiratory gases from the patient. An expiratory circuit receives the
expiratory gases from the patient interface. An expiratory pressure device receives
expiratory gases from the expiratory circuit and regulates the expiratory gases to a
positive end expiration pressure. An occlusion device is positioned within the expiratory
circuit upstream from the expiratory pressure device. The occlusion device is configured
to permit occlusion of the expiratory circuit at desired times such that the pressure within
the inspiratory circuit rises to the peak inspiration pressure.
[0006] Another preferred embodiment involves a combination infant positive
airway pressure and resuscitation system. The system includes a supply of breathing gas
and an inspiratory pressure device that receives a flow of breathing gas from the supply of
breathing gas. The inspiratory pressure device is capable of outputting the flow of
breathing gas at a desired peak inspiration pressure to an inspiratory circuit. A patient
interface receives the flow of breathing gas from the inspiratory circuit, wherein the
patient interface is configured to deliver the flow of breathing gas to an infant patient and
receive expiratory gases from the patient. An expiratory circuit receives the expiratory
gases from the patient interface. An oscillatory expiratory pressure device receives
expiratory gases from the expiratory circuit and regulates the expiratory gases to a mean
positive end expiration pressure with pressure oscillations relative to the mean pressure.
An occlusion device is positioned within the expiratory circuit and is configured to permit
occlusion of the expiratory circuit at desired times such that the pressure within the
inspiratory circuit rises to the peak inspiration pressure.
[0007] In some arrangements of the above-described systems, the expiratory
pressure device is or includes a water resistance valve, which can be adjustable to permit
adjustment of the positive end expiration pressure. The occlusion device can be a manual
push button valve or a clamp valve, among other possible valve types. In some
arrangements, the system can include a humidifier positioned within the inspiratory
circuit between the inspiratory pressure device and the patient interface. Preferably, the
occlusion device is located less than 500 millimeters from the patient end of the
expiratory circuit. In some arrangements, the expiratory circuit can include an expiratory
hose coupled to the patient interface and the occlusion device can be located within the
expiratory hose.
[0008] In some arrangements, a source of breathing gas is provided separately
from the inspiratory pressure device, such as via a bottle or wall source. In other
arrangements, the source of breathing gas is ambient air and a flow of air is generated by
a flow generator or blower. The blower can be provided in an integrated unit with the
inspiratory pressure device (e.g., resuscitator) and the humidifier. In some arrangements,
the blower and humidifier are contained or associated with a first housing and the
inspiratory pressure device (e.g., resuscitator) can be integrated with a second housing,
which can be removed from the first housing. In some arrangements, the humidifier is
contained or associated with a first housing and the inspiratory pressure device (e.g.,
resuscitator) can be integrated with a second housing, which can be removed from the
first housing. In some arrangements, the blower can be integrated with the humidifier and
the inspiratory pressure device (e.g., resuscitator) can be a separate component.
[0009] Another preferred embodiment involves a combination infant positive
airway pressure and resuscitation system. The system includes a patient interface that
receives expiratory gases from the patient and an expiratory circuit that receives the
expiratory gases from the patient interface. An expiratory pressure device receives
expiratory gases from the expiratory circuit and regulates the expiratory gases to a
positive end expiration pressure. An occlusion device is positioned within the expiratory
circuit upstream from the expiratory pressure device and is configured to permit occlusion
of the expiratory circuit at desired times such that the pressure within the system rises
above the positive end expiration pressure.
[0010] A preferred embodiment involves a breathing circuit for a combination
infant positive airway pressure and resuscitation system. The circuit includes an
expiratory circuit that is configured for connection to a patient interface to receive
expiratory gases from the patient interface and an inspiratory circuit that is configured for
connection to the patient interface to deliver a flow of breathing gas to the patient
interface. An occlusion device is configured to permit occlusion of the expiratory circuit
at desired times such that the pressure within the system rises above the positive end
expiration pressure.
[0011] In some arrangements of the above-described circuits, the expiratory
circuit is further configured for connection to an expiratory pressure device that receives
expiratory gases from the expiratory circuit and regulates the expiratory gases to a
positive end expiration pressure. The occlusion device can comprise a manual push
button valve. The occlusion device can comprise a clamp. The occlusion device can be
located less than 500 millimeters from the patient interface along the expiratory circuit.
The occlusion device can be located in the expiratory circuit. In some embodiments, the
occlusion device can be located in the patient interface.
[0012] Another preferred embodiment involves a method of providing
continuous positive airway pressure and resuscitation to an infant, including using an
inspiratory pressure device to provide a flow of breathing gas, the inspiratory pressure
device capable of generating a peak inspiratory pressure in the flow of breathing gas. The
flow of breathing gas is supplied to an infant patient through a patient interface and
expiratory gases are received from the infant patient through the patient interface. A
water resistance valve or other type of oscillatory resistance valve is utilized to vent the
flow of breathing gas and expiratory gases and maintain a mean positive end expiration
pressure within the patient interface that is less than the peak inspiratory pressure. A
resuscitation breath is provided to the infant patient by blocking the flow of breathing gas
and expiratory gases between the patient interface and the water resistance valve such that
the pressure within the patient interface increases to the peak inspiratory pressure.
[0013] In some applications, the method can include providing repeated
resuscitation breaths to the infant patient by repeatedly alternating between blocking and
allowing the flow of breathing gas and expiratory gases between the patient interface and
the water resistance valve. In some applications, the blocking of the flow of breathing gas
and expiratory gases between the patient interface and the water resistance valve can be
accomplished by actuating a push button occlusion valve or by clamping a portion of an
expiratory tube. In some applications, the flow of breathing gas can be passed through a
humidifier after the inspiratory pressure device and before the patient interface. The
positive end expiration pressure can be adjusted by adjusting a depth of an outlet of the
flow of breathing gas and expiratory gases within a water reservoir of the water resistance
valve.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Preferred embodiments, having certain features, aspects and
advantages of the present invention, are described with reference to the accompanying
drawings. The drawings contain six (6) figures.
[0015] Figure 1 is an illustration of an infant patient receiving CPAP therapy
and/or resuscitation therapy from a system including an inspiratory pressure device, a
humidifier, a patient interface and an expiratory pressure device.
[0016] Figure A is an illustration of an infant patient and an alternative
patient interface.
[0017] Figure 2 is a partial cross-sectional view of a linear motion, push
button occlusion valve.
[0018] Figures 3A and 3B are partial cross-sectional views of a clamp-type
occlusion valve in which a tube can be collapsed or occluded by a clamp. Figure 3A
shows the tube in an open configuration and Figure 3B shows the tube in a collapsed or
occluded configuration.
[0019] Figure 4 is an illustration of a modification of the system of Figure 1,
in which the inspiratory pressure device is integrated with the humidifier.
[0020] Figure 5 is a partial sectional view of the integrated inspiratory
pressure device and humidifier of Figure 4.
[0021] Figure 6 is an illustration of another modification of the system of
Figure 1, in which a flow generator is integrated with the humidifier.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0022] Figure 1 illustrates a combination infant positive airway pressure
(PAP) or continuous positive airway pressure (CPAP) and resuscitation system, generally
referred to by the reference numeral 10. The system 10 is capable of providing PAP or
CPAP therapy to a neonate or an infant patient 2 for an extended period of time, while
also permitting resuscitation breaths to be delivered to the infant patient 12 if or when
necessary. Preferably, both the PAP or CPAP therapy and the resuscitation breaths are
delivered through a single patient interface 14 without requiring removal of the interface
14 from the infant patient 12. The present system 10 is disclosed herein in the context of
continuous positive airway pressure (CPAP) therapy; however, the system 1 could also
provide other types or modes of positive airway pressure (PAP) therapy. Accordingly,
references to CPAP therapy herein are understood to also include other types of PAP
therapies, unless specifically noted otherwise.
[0023] The illustrated system 10 includes a source of breathing gas 20, which
can be a gas cylinder (not shown), a wall supply 20, or any other suitable source of
breathing gas. The breathing gas can be air, oxygen, a blend of air and oxygen, or any
other suitable gas for use in respiratory therapy. The source of breathing gas 20 provides
a flow of breathing gas at an initial feed pressure or within an initial feed pressure range.
The flow rate of the flow of breathing gas can be adjusted by a suitable flow meter or gas
blender 22 to a suitable level for the desired therapy.
[0024] A suitable conduit, such as a gas supply line 24 supplies the flow of
breathing gas to an inspiratory pressure device 26, which can be a resuscitator. More
preferably, the inspiratory pressure device 26 is an infant resuscitator, such as an infant
resuscitator sold by Fisher and Paykel Healthcare, the Assignee of the present application,
under the NEOPUFF trademark. Although referred to herein as a "resuscitator" for
convenience, it is understood that the term can encompass other suitable types of
inspiratory pressure devices capable of providing a breathing gas at a controlled output
pressure.
[0025] Preferably, the resuscitator 26 is capable of receiving a flow of
breathing gas from the source of breathing gas 20 and outputting the flow of breathing gas
at a controlled pressure greater than atmospheric pressure. In particular, the resuscitator
26 can output the flow of breathing gas at a peak inspiratory pressure (PIP), which
preferably can be up to about 75 cmH 0 or greater. Preferably, the resuscitator 26
includes an adjustment mechanism, such as an adjustment valve 28, which allows the PIP
to be adjusted to a desired pressure level. Preferably, the resuscitator 26 also incorporates
a pressure relief valve 30 that regulates a maximum pressure within the system 10. The
pressure relief valve 30 can be adjustable such that the maximum system pressure can be
adjusted. For example, an adjustment range can be between about 5-70 cmH20 . The
pressure relief level can be factory set to a particular value, such as about 40 cmH20 , for
example. However, in alternative arrangements, a separate pressure regulator could be
provided within the system 10 to regulate the maximum system pressure. Such a pressure
regulator is described in U.S. Patent No. 6,644,313, which is incorporated by reference
herein in its entirety. In embodiments having a blower unit, a pressure relief valve may
not be necessary because the maximum achievable pressure of the system can be
regulated by the blower unit. The blower unit can be designed so that the maximum
pressure it can produce is lower than a desired pressure relief level. In other
embodiments, the maximum achievable pressure of the blower unit can be limited by
software in the system.
[0026] The flow of breathing gas outputted from the resuscitator 26 preferably
is delivered to an optional humidifier system 32 by a suitable conduit, such as an
inspiratory tube or supply tube 34. In some embodiments, the resuscitator and the
humidifier system can be integrated into a single unit, as discussed below. The humidifier
system 32 provides humidity or vaporized liquid, such as water, to the flow of breathing
gas received from the resuscitator 26 to output a flow of humidified breathing gas to the
patient interface 14 through a suitable conduit, such as a supply tube 36. The humidifier
system 32 can include a humidifier unit or humidifier 40 and a humidity chamber 42.
The humidity chamber 42 holds a volume of liquid, such as water, which is heated by the
humidifier 40 to create a vapor within the humidity chamber 42 that is transferred to the
flow of breathing gas. The humidity chamber 42 can be an auto-fill variety, in which a
source of liquid 44 is connected to the humidity chamber 42 to refill the volume of liquid,
as appropriate. A suitable humidifier 40 is the MR850 Humidifier sold by the Assignee
of the present application. A suitable humidity chamber 42 is the MR225 or MR290
humidity chamber sold by the Assignee of the present application. The humidifier system
32 can output a flow of humidified breathing gas at a desired temperature and absolute
humidity, such as an optimal temperature of about 37 degrees Celsius and absolute
humidity of about 44 mg/L, or within a desirable or acceptable range of the optimal
temperature and absolute humidity.
[0027] The supply tube 36 can be a heated supply tube such that a temperature
of the flow of breathing gas is maintained at an elevated level within the supply tube 36
and to avoid or limit condensation within the supply tube 36 or patient interface 14. A
heating element cable 46 can connect a heating element of the supply tube 36 to the
humidifier 40 (or other power/heat source) to power the heating element. A sensor or
probe 48 can be coupled to the humidifier 40 and supply tube 36 to detect the temperature
and/or flow rate of the flow of breathing gas through the supply tube 36. Preferably, the
sensor 48 is spaced from the inlet end of the supply tube 36 and can be located at the
outlet end of the supply tube 36. The sensor 48 can include a wire that couples the sensor
48 to the humidifier 40. The humidifier 40 can utilize information from the sensor 48 to
control the operating parameters of the humidifier 40, for example, to maintain the
temperature and/or humidity of the flow of breathing gas within the supply tube 36 at a
desirable level or range.
[0028] From the humidifier system 32, the flow of breathing gas is supplied to
the patient interface 14, which can be any suitable type of interface capable of supplying a
breathing gas to the respiratory system of the patient. The illustrated interface 14 is a
lateral nasal interface, which includes nasal cannula or nasal prongs that are inserted into
the nostrils of the infant patient 12. In a lateral interface, the inlet and outlet are laterally
spaced on opposing sides of the nasal cannula or prongs and a midline of the infant
patient 12. Figure 1A illustrates an alternative nasal interface 14A, which can be referred
to as a midline nasal interface. The midline nasal interface 14A positions the inlet and the
outlet of the interface 14A are located in line with the nasal cannula or nasal prongs and
substantially along the midline of the infant patient 12. The inlet and outlet of the
interface 14A can be positioned side-by-side; however, in a preferred arrangement, the
inlet and outlet are stacked one on top of the other. One suitable interface 14A is an
infant nasal tube or mask in combination with nasal prongs sold by the Assignee of the
present application under the trademark FLEXITRUNK. However, other suitable patient
interfaces 14 can also be used, such as a face mask that covers both the nose and mouth of
the infant patient 12 (e.g., RD Series Infant Resuscitation Masks sold by the Assignee of
the present application) or an appropriate interface device in combination with an
endotracheal tube. An infant resuscitation mask is described in U.S. Patent No.
7,341,059, which is hereby incorporated by reference in its entirety.
[0029] Preferred interfaces 14 provide a sealed system that delivers the flow
of breathing gas to the infant patient 12 and receives expiratory gases from the patient 12.
Preferably, the system 10 is a biased flow system in which breathing gas is constantly
flowing within the system 10 generally in a direction from the inlet of the patient interface
14 to the outlet of the patient interface 14. Thus, the infant patient 12 can inhale a portion
of the flow of breathing gas and the remainder is passed through the patient interface 14.
Exhaled or expiratory gases can mix with the flow of breathing gas and exit the patent
interface 14 along with the unused portion of the flow of breathing gas. For convenience,
the gases exiting the patient interface 14 are referred to as expiratory gases or the flow of
breathing gas, although it is understood that either or both of patient exhaled gases and
unused breathing gases can be present at any particular point in time.
[0030] Expiratory gases flow from the patient interface 14 to an expiratory
pressure device 60, which is configured to regulate the minimum pressure within the
system 10, preferably to a level above ambient or atmospheric pressure. Preferably, the
expiratory pressure device 60 is connected to the patient interface 14 by a suitable
conduit, such as an expiratory hose 62. However, in an alternative arrangement, the
expiratory pressure device 60 can be connected directly to or integrated with the patient
interface 14.
[0031] Preferably, the expiratory pressure device 60 is configured to provide a
minimum pressure or minimum backpressure within the system 10 and, in particular, at
the patient interface 14, which can be referred to as the positive end expiration pressure
(PEEP). In the illustrated system 10, the PEEP is equivalent to, or generally equivalent
to, the continuous positive airway pressure (CPAP). Accordingly, such a device can be
referred to as a CPAP generator. However, preferably, the expiratory pressure device 60
is an oscillatory valve capable of providing pressure oscillations relative to a mean PEEP
pressure. It is believed that such pressure oscillations are beneficial to the infant patent
12 and may result in improved gas exchange and reduce the infant patient's 12 work of
breathing. Thus, an oscillatory pressure expiratory pressure device 60 is particularly
preferred. One type of oscillating pressure expiratory pressure device 60 is a fluid
resistance valve, in particular a liquid or water resistance valve, which is often referred to
as a bubbler. In general, a water resistance valve delivers the expiratory gases to an outlet
that is submerged in a water reservoir resulting in a resistance to the exit of the expiratory
gases that is greater than that caused by ambient or atmospheric pressure and related to
the depth of the outlet relative to a surface of the water within the water reservoir. In
some arrangements, the depth of the outlet is adjustable to allow the PEEP to be adjusted
to a desired level. One suitable bubbler is the Bubble CPAP generator sold by the
Assignee of the present application. Additional details of a suitable bubbler device are
described in U.S. Patent No. 6,805,120, which is incorporated by reference herein in its
entirety. Preferably, the bubbler (or other oscillatory pressure device) is capable of
producing vibrations in the infant patient's chest at a frequency of between about 5-30
Hz.
[0032] The illustrated system 10 also includes an occlusion device or
occlusion valve 70 that is configured to selectively block the flow of gases within the
system 10 and preferably block the flow of expiratory gases, such as within the patient
interface 14, expiratory tube 62 or expiratory pressure device 60. Preferably, the
occlusion valve 70 is located upstream of the expiratory pressure device 60 and
downstream of the patient interface 14, such as within the expiratory tube 62. Preferably,
the occlusion valve 70 is located at or near the patient interface 14, such as within about
500 millimeters or less of the patient interface 14. However, in other arrangements, the
occlusion valve 70 can be integrated with the patient interface 14 or expiratory pressure
device 60. The occlusion valve 70 is configured to block the exit of gases from the
system 10 to a sufficient extent such that the gas pressure within the system 10 rises
above the PEEP. With the exit of gases from the system 10 blocked, the inspiratory
pressure device 26 can increase the pressure in the system 10 preferably to or near the set
PIP level. The occlusion valve 70 can completely or substantially completely block the
flow of gas within the system 10, or can block or interrupt the flow to a sufficient extent
to allow the inspiratory pressure device 26 or integrated unit 90 to raise the pressure
toward the PIP. Preferably, the occlusion valve 70 can block the flow of gas within the
system 10 to a sufficient extent that the inspiratory pressure device 26 or integrated unit
90 can raise the pressure within the system 10 to or substantially to the PIP pressure.
However, to quickly and accurately achieve the PIP pressure, it is desirable that the
occlusion valve 70 completely or substantially completely block the flow of gas within
the system 10. Although described as a sealed system, it is understood that some leakage
of gas may occur from the system 10, such as between the patient interface 14 and the
patient 12, for example. In addition, pressure losses may occur throughout the system 10
such that the pressure is not the same throughout the entire system 10. Accordingly, it is
understood that the PEEP or PIP may vary between the point of measurement and some
other point within the system 10. Therefore, it is understood that discussion of specific
pressures or pressure ranges herein, such as PIP or PEEP, incorporates a range of
acceptable variation, which can result from pressure leakage, pressure loss or
measurement error.
[0033] In operation, the occlusion valve 70 can be utilized to perform a
resuscitation procedure or resuscitation therapy by raising the pressure within the system
10 to at or near the PIP pressure to deliver a resuscitation breath to the infant patient 12 in
a manner similar to a conventional resuscitation procedure. However, advantageously,
with the present system 10, resuscitation breaths can be provided to an infant patient 12
that is undergoing CPAP therapy immediately and without requiring additional equipment
or set-up. Furthermore, the CPAP therapy can be immediately resumed after the
resuscitation procedure. Preferably, the resuscitation breaths can be provided through the
same patient interface 14 as the CPAP therapy without removal or exchange of the
interface and with breathing gases flowing in the same direction within the system 10 as
the CPAP therapy. The occlusion valve 70 can be used to provide repeated resuscitation
breaths to the infant patient 12 at or near PIP pressure with intervening periods of PEEP.
The resuscitation breaths delivered by use of the occlusion valve 70 can be at any suitable
rate, such as about 40-60 breaths per minute. The relative duration of the resuscitation
breath time at PIP pressure to the exhalation time at PEEP can be any suitable ratio, such
as 40:60, 50:50, 60:40, or any value in between. The resuscitation procedure typically
lasts for less than 30 minutes or less than 5 minutes. Often, the resuscitation procedure
lasts between about 3-5 minutes. Thus, the present system 10 is particularly
advantageous in reducing the switchover time between CPAP therapy and resuscitation
therapy, which avoids delay in providing resuscitation therapy once it is recognized as
necessary or desirable.
[0034] The occlusion valve 70 can be of any suitable arrangement or structure
to selectively accomplish a partial or complete occlusion of gas flow within the system
10. Preferably, the occlusion valve 70 allows the cycling between an occluded or closed
position and an open position at a suitable rate, such as the rates described herein. In
some arrangements, the occlusion valve 70 is a manual valve that is operated by manually
by a caregiver. Accordingly, preferably the occlusion valve 70 facilitates repeated cycling
between the open and closed position multiple times per minute.
[0035] For example, Figure 2 illustrates a push button valve arrangement 70
having a manually operated push button 72 that actuates a valve body 74 movable
between an open position and a closed position. The valve body 74 can simply move into
or out of a flow passage P of the system 10 (linear movement or translation) to selectively
allow and occlude gas flow within the system 10. In some embodiments, the valve
arrangement can include a safety feature to help prevent accidental actuation. For
example, the push button may be lockable in the open position by rotating the push button
a quarter turn. In order to use the valve arrangement, the user can rotate the push button
to unlock before actuating. Preferably, the valve body 74 is biased to the open position by
a biasing member, such as a spring 76, so that gas flow is normally unobstructed. The
valve body 74 can be movable to the closed position (e.g., using the manual push button
72) when it is desired to deliver a resuscitation breath at PIP. In other arrangements, the
valve 70 could be a rotatable valve, such as a stopcock. Figure 3 illustrates another
possible occlusion valve arrangement 70, in which a compliant section of tubing 78 that
has sufficient resilience to remain open in the absence of an external force (Figure 3A),
but can be collapsed to a closed position in response to an external squeezing force
(Figure 3B), such as a force applied by a clamping mechanism 79. In still other
arrangements, the valve 70 could be automatically movable (e.g., electronically actuated).
[0036] As described, the occlusion valve 70 can be positioned in any suitable
location within the system 10. The system 0 can be considered to have an inspiratory
circuit and an expiratory circuit. In the illustrated arrangement, the inspiratory circuit can
include all or portions of the source of breathing gas 20, the gas supply line 24, the
inspiratory pressure device 26, the supply tube 34, the humidifier system 32, and the
supply tube 36. The expiratory circuit can include all or portions of the expiratory tube
62 and the expiratory pressure device 60. A portion of the patient interface 14 can be
predominantly occupied by a flow of inspiratory breathing gas prior to inspiration by the
infant patient 1 or prior to availability to the infant patient 12, while another portion of
the patient interface 14 can be predominantly occupied by a flow of expiratory gas
exhaled by the infant patient 12 or that has bypassed the infant patient 12. Accordingly,
the patient interface 4 can be considered to form a part of each of the inspiratory circuit
and the expiratory circuit. A portion of the patient interface 14 can also include a mixture
of inspiratory gas and expiratory gas, at least for certain time durations, and may not be
considered part of either of the inspiratory circuit or the expiratory circuit or may be
considered as a part of each.
[0037] The various components of the system 10, including those described
above, can be arranged and/or mounted in any suitable manner. Some or all of the
components can be stationary (e.g., wall mounted) or movable. In the illustrated
arrangement, some of the components are mounted to a support pole 80, which includes a
base portion 82 having a plurality of rollers or casters 84 to provide mobility. A suitable
pole 80 is the 900MR292 or 900MR293 pole sold by the Assignee of the present
application. In the illustrated arrangement, the inspiratory pressure device 26, the
humidifier system 32 and the expiratory pressure device 60 are mounted to the support
pole 80. Although not specifically illustrated, the source of water 44 preferably is also
supported by the support pole 80. In other arrangements, some of the components could
be mounted on another support pole 80. The source of breathing gas 20 and the flow
meter or gas blender 22 can be mobile or can be stationary (e.g., wall mounted). In one
arrangement, for example, the resuscitator 26 can be integrated with an infant warmer,
such as the 900 Series infant warmers sold by the Assignee of the present invention.
[0038] To set up the system 10 for use, the components can be gathered and
mounted to the support pole 80 or other support structure, if necessary or desired. The
components can be connected to a power source, if necessary, and turned on. The
inspiratory pressure device 26 can be coupled to the source of breathing gas 20 through
the flow meter or gas blender 22 by the gas supply line 24. The humidifier system 32 can
be coupled to the inspiratory pressure device 26 by the supply tube 34. The source of
water 44 can be coupled to the humidity chamber 42. The patient interface 14 can be
coupled to the humidifier system 32 by the supply tube 36. The expiratory pressure
device 60 can be coupled to the patient interface 14 by the expiratory tube 62. The
occlusion valve 70 can be integrated into the expiratory tube 62; however, the occlusion
valve 70 can also be assembled to the expiratory tube 62 (such as intermediate two tube
portions of the expiratory tube 62) or otherwise assembled in a suitable location within
the system 10, as described above.
[0039] If necessary, the expiratory pressure device 60 can be filled with a
liquid, such as about 500 milliliters of water. If adjustable, the expiratory pressure device
60 can be initially adjusted to a maximum pressure level (maximum PEEP). The
humidifier system 32 can be adjusted to a desired temperature and absolute humidity,
such as about 37 degrees Celsius and 44 mg L. The flow meter or gas blender 22 can be
adjusted to a desired flow rate, preferably less than 15 liters per minute (LPM). In
embodiments having a blower unit, the flow meter or gas blender can be integrated with
the blower unit. More preferably, the flow rate is adjusted to between about 6-8 LPM.
[0040] If necessary or desirable, the pressure relief valve 30 of the inspiratory
pressure device 26 can be adjusted to a suitable pressure relief level. The pressure relief
valve 30 can be factory set to a pressure relief level, such as about 40 cmH20. The
pressure relief valve 30 can be set to a lower level, such as between about 5-70 cmH20
and, more preferably, 30-40 cmH20. To set the level of the pressure relief valve 30, the
PIP adjustment of the inspiratory pressure device 26 is adjusted to a maximum level. The
patient interface 14 can be blocked or connected to a test lung apparatus, such as the
RD020-01 test lung apparatus sold by the Assignee of the present application. The
occlusion valve 70 can be actuated to allow the pressure within the system 0 to rise to
the pressure relief level, which can be adjusted to a desired level. With the occlusion
valve 70 still actuated, the PIP can be adjusted to a desirable level, preferably less than
about 75 cmH20. More preferably, the PIP is between about 10-40 cmH20 or 20-30
cmH20. In one application, the PIP pressure is adjusted to about 20 cmH20, using the PIP
valve 28. The occlusion valve 70 can be moved to an open position such that the system
pressure is reduced to the PEEP value as determined by the expiratory pressure device 60.
The PEEP level can be adjusted to a desirable pressure, such as less than about 25 cmH20,
by adjusting a depth of the gas outlet within the water reservoir. Preferably, the PEEP
level is adjusted to less than about 15 cmH20, less than about 9 cmH20 or less than about
5 cmH20. In one application, the PEEP level is set to about 5 cmH20. If necessary, the
test lung apparatus can be removed and the system 10 is ready for use.
[0041] To use the system 10, the patient interface 14 can be applied to an
infant patient 12 following an appropriate methodology. For example, a face mask can be
positioned over the nose and mouth of the infant patient 12 and, if desired, held in place
by hand, a strap or other retention device. If an endotracheal tube is used, the interface 14
or portion of the interface 14 can be coupled to the endotracheal tube. In the illustrated
arrangement, the nasal prongs can be coupled to the nasal mask or tube and the nasal
prongs can be inserted into the nostrils of the infant patient 12. The nasal mask 14 can be
held in place by any suitable retention mechanism, such as a chin strap or head strap.
[0042] Once the patient interface 14 is in place on the infant patient 12, the
CPAP therapy can be commenced. A flow of breathing gas is supplied to the infant
patient 1 by the patient interface 14 at the CPAP or PEEP level, as regulated by the
expiratory pressure device 60. As discussed, preferably the expiratory pressure device 60
is configured to produce pressure oscillations within the system 10, which is believed to
have an improved therapeutic effect on the infant patient 1 . The CPAP therapy can
continue for a desired period of time.
[0043] If necessary or desirable, resuscitation therapy can be administered. As
described above, the occlusion valve 70 can be actuated to block the exit of expiratory
gases from the system 10 and cause the pressure within the system 10 to rise toward or to
the PIP pressure to deliver a resuscitation breath to the infant patient 12. The occlusion
valve 70 can be moved to an open position, or allowed to return to an open position, to
return the system to the PEEP. In some arrangements, the actuation of the occlusion
valve 70 is accomplished manually. The actuation and release of the occlusion valve 70
can be repeated at a desired frequency, such as between about 40-60 breaths per minute,
for a suitable duration, such as about 3-5 minutes. However, if necessary or desirable, the
duration of the resuscitation therapy can be up to 15-30 minutes, or longer. At the
conclusion of the resuscitation therapy, the system 10 can automatically return to the
CPAP mode at the PEEP. Accordingly, with the illustrated system 0, resuscitation
therapy can be immediately commenced on an infant patient 12 that is undergoing CPAP
therapy without requiring the set-up of additional equipment and without requiring the
replacement of the patient interface 14.
[0044] Figures 4 and 5 illustrate a modification of the system 10 of Figure 1.
Because the system of Figures 4 and 5 is similar to the system 10 of Figure 1 in many
respects, the same reference numbers are used to indication the same or corresponding
components. In the system of Figures 4 and 5, the resuscitator 26 (or other inspiratory
pressure device) is integrated with the humidifier 32 in a resuscitator/humidifier unit 90
(hereinafter "integrated unit 90"). In addition, preferably, the source of breathing gas 20
is or includes ambient air from an environment adjacent the integrated unit 90. Therefore,
the integrated unit 90 preferably comprises a flow generator or flow source, such as a fan,
gas pump or blower 92 (Figure 5), which generates a flow of air. In some embodiments,
however, the integrated unit 90 can be connected to a source of breathing gas, such as a
gas cylinder or a wall supply, instead of or in addition to the flow generator. In some
arrangements, the system can utilize supplemental breathing gases (oxygen or other
suitable respiratory gases) that are blended in combination with air. However, in many
arrangements, only air is used and the source of breathing gas (reference number 20 in
Figure 1) can be omitted.
[0045] In the illustrated arrangement, the integrated unit 90 generates a flow
of breathing gas (e.g., air) and outputs the flow of breathing gas at a controlled pressure
greater than atmospheric pressure to the humidifier, which humidifies the flow of
breathing gas. The flow of humidified breathing gas is delivered to the patient 12 via the
supply tube 36 and patient interface 14. Exhaled and unused gases are delivered to the
expiratory pressure device 60 via the expiratory hose 62. The expiratory pressure device
60 can provide a minimum pressure or minimum backpressure within the system and, in
particular, at the patient interface 14 preferably to or near the PEEP pressure. The
occlusion valve 70 can be used to block the flow of breathing gas such that the inspiratory
pressure device 26 can increase the pressure in the system preferably to or near the set PIP
level. The system of Figures 4 and 5 preferably operates in substantially the same manner
as described above with respect to the system 10 of Figure 1.
[0046] With reference to Figure 5, in addition to the blower 92, the integrated
unit 90 preferably includes a filter 94 upstream from the blower 92. The filter 94 is of a
suitable arrangement to separate impurities or other undesirable elements from the
ambient air that is used to generate the flow of air within the system. The filter 94 and the
blower 92 preferably can be coupled to or contained within a housing 96 that contains
portions of the humidifier 40 and supports the humidifier chamber 42. The pressure
adjustment valve 28 and a manometer 98, or other pressure gauge or measurement device,
can be coupled to or contained within a housing 100 that is separate from the housing 96.
Preferably, the housing 100 can be removable from the housing 96. When the housing
100 is removed, the integrated unit 90 can be used as a blower 92 and humidification
system 32 without the resuscitation feature. In the illustrated arrangement, the housing
100 defines or contains a conduit 102 for delivering the flow of breathing gas from the
blower 92 to the humidification chamber 42 of the humidifier system 32. When the
housing is removed, an auxiliary conduit (not shown) can be utilized in place of the
conduit 102. Alternatively, an auxiliary conduit can be integrated with or otherwise
incorporated with the housing 96 that is utilized when the housing 100 is removed. A
valve arrangement could be configured to automatically switch between the conduit 102
and the auxiliary conduit depending on the presence or absence of the housing 100.
[0047] With reference to Figure 6, in another modification of the systems of
Figure 1 and Figures 4 and 5, the flow generator (hereinafter "blower 92") is integrated
with the humidifier 40 of the humidification system 32. However, unlike the system of
Figures 4 and 5, the resuscitator 26 is a separate system component from the humidifier
40, humidification chamber 42 or the entire humidifier system 32. Thus, in the system of
Figure 6, the blower 92 is connected to the resuscitator 26 via the supply line 24 to deliver
the flow of air (or other breathing gas) from the blower 92 to the resuscitator 26. The
flow of air then flows from the resuscitator 26 to the humidification chamber 42 of the
humidifier system 32 and to the patient 12 as described above. If the resuscitator 26 is
not necessary or desired, the blower 92 can be connected to the humidification chamber
42 of the humidifier system 32, without passing through the resuscitator 26, via a suitable
internal or external auxiliary conduit, as described above.
[0048] Although described in the context of an infant patient system, the
illustrated system can be used in, or modified for use in, other applications or contexts, as
well. Thus, although this invention has been disclosed in the context of certain preferred
embodiments and examples, it will be understood by those skilled in the art that the present
invention extends beyond the specifically disclosed embodiments to other alternative
embodiments and/or uses of the invention and obvious modifications and equivalents
thereof. In particular, the skilled artisan will appreciate, in view of the present disclosure,
that certain advantages, features and aspects of the system may be realized in a variety of
other applications, many of which have been noted above. Additionally, it is
contemplated that various aspects and features of the invention described can be practiced
separately, combined together, or substituted for one another, and that a variety of
combination and subcombinations of the features and aspects can be made and still fall
within the scope of the invention. Thus, it is intended that the scope of the present
invention herein disclosed should not be limited by the particular disclosed embodiments
described above, but should be determined only by a fair reading of the claims.
WHAT IS CLAIMED IS:
1. A combination infant positive airway pressure and resuscitation system,
comprising:
an integrated inspiratory pressure device comprising a resuscitator and a
humidifier, wherein the resuscitator is capable of regulating a flow of breathing
gas to a desired peak inspiration pressure, and wherein the humidifier humidifies
the flow of breathing gas;
an expiratory pressure device configured to receive expiratory gases from
an expiratory circuit and regulate the expiratory gases to a positive end expiration
pressure;
an occlusion device within the expiratory circuit upstream from the
expiratory pressure device, wherein the occlusion device is configured to permit
occlusion of the expiratory circuit at desired times such that the pressure within
the inspiratory circuit rises to the peak inspiration pressure of the resuscitator.
2. The combination infant positive airway pressure and resuscitation system
of Claim 1, wherein the resuscitator is separable from the humidifier.
3. The combination infant positive airway pressure and resuscitation system
of Claim 2, wherein the resuscitator is integrated with a first housing and the humidifier is
integrated with a second housing.
4. The combination infant positive airway pressure and resuscitation system
of Claim 3, further comprising a flow generator that generates the flow of breathing gas.
5. The combination infant positive airway pressure and resuscitation system
of Claim 3, wherein the flow generator is integrated with the second housing.
6. The combination infant positive airway pressure and resuscitation system
of Claim 1, wherein the expiratory pressure device comprises a water resistance valve.
7. The combination infant positive airway pressure and resuscitation system
of Claim 12, wherein the water resistance valve is adjustable to permit adjustment of the
positive end expiration pressure.
8. The combination infant positive airway pressure and resuscitation system
of Claim 1, wherein the occlusion device comprises a manual push button valve.
9. The combination infant positive airway pressure and resuscitation system
of Claim 1, wherein the occlusion device comprises a clamp.
10. The combination infant positive airway pressure and resuscitation system
of Claim 1, wherein the occlusion device is located less than 500 millimeters from a
patient end of the expiratory circuit.
11. A combination infant positive airway pressure and resuscitation system,
comprising:
an inspiratory pressure device that outputs a flow of breathing gas at a
desired peak inspiration pressure;
an inspiratory circuit that receives the flow of breathing gas from the
inspiratory pressure device;
a patient interface that receives the flow of breathing gas from the
inspiratory circuit, wherein the patient interface is configured to deliver the flow
of breathing gas to an infant patient and receive expiratory gases from the patient;
an expiratory circuit that receives the expiratory gases from the patient
interface;
an expiratory pressure device that receives expiratory gases from the
expiratory circuit and regulates the expiratory gases to a positive end expiration
pressure;
an occlusion device within the expiratory circuit upstream from the
expiratory pressure device, wherein the occlusion device is configured to permit
occlusion of the expiratory circuit at desired times such that the pressure within
the inspiratory circuit rises to the peak inspiration pressure.
12. The combination infant positive airway pressure and resuscitation system
of Claim 11, wherein the expiratory pressure device comprises a water resistance valve.
13. The combination infant positive airway pressure and resuscitation system
of Claim 12, wherein the water resistance valve is adjustable to permit adjustment of the
positive end expiration pressure.
14. The combination infant positive airway pressure and resuscitation system
of Claim 1, wherein the occlusion device comprises a manual push button valve.
15. The combination infant positive airway pressure and resuscitation system
of Claim 1, wherein the occlusion device comprises a clamp.
16. The combination infant positive airway pressure and resuscitation system
of Claim 1 , further comprising a humidifier positioned within the inspiratory circuit
between the inspiratory pressure device and the patient interface.
17. The combination infant positive airway pressure and resuscitation system
of Claim 11, wherein the occlusion device is located less than 500 millimeters from the
patient interface along the expiratory circuit.
18. The combination infant positive airway pressure and resuscitation system
of Claim 11, wherein the expiratory circuit comprises an expiratory hose coupled to the
patient interface and the occlusion device is located within the expiratory hose.
. A breathing circuit for a combination infant positive airway pressure and
resuscitation system, comprising:
an expiratory circuit that is configured for connection to a patient interface
to receive expiratory gases from the patient interface;
an inspiratory circuit that is configured for connection to the patient
interface to deliver a flow of breathing gas to the patient interface;
an occlusion device configured to permit occlusion of the expiratory
circuit at desired times such that the pressure within the system rises above a
positive end expiration pressure.
20. The breathing circuit for a combination infant positive airway pressure and
resuscitation system of Claim 19, wherein the expiratory circuit is further configured for
connection to an expiratory pressure device that receives expiratory gases from the
expiratory circuit and regulates the expiratory gases to a positive end expiration pressure.
21. The breathing circuit for a combination infant positive airway pressure and
resuscitation system of Claim 19, wherein the occlusion device comprises a manual push
button valve.
22. The breathing circuit for a combination infant positive airway pressure and
resuscitation system of Claim 19, wherein the occlusion device comprises a clamp.
23. The breathing circuit for a combination infant positive airway pressure and
resuscitation system of Claim 19, wherein the occlusion device is located less than 500
millimeters from the patient interface along the expiratory circuit.
24. The breathing circuit for a combination infant positive airway pressure
and resuscitation system of Claim 19, wherein the occlusion device is located in the
expiratory circuit.