|
Why is there no top inner wall on the Giraffe® Incubator?
First, we need to look at the function of an inner wall. Convective airflow
within a Care Plus® incubator (as well as some other types of incubators)
has traditionally been unidirectional. This means that warm air must traverse
from its origin underneath a mattress deck, up the front wall, over the top
wall, and down the rear walls of the device. As the air travels along the Plexiglas
surface of the device wall from the point that it enters the infant compartment,
it (the air) progressively cools slightly along the path. Air cooling results
in a temperature decrement of the upper, top, and back walls. This decreased
wall surface temperature acts as a potential source of radiant heat loss to
the infant in a single-wall device. The addition of a second wall inside the
incubator coupled with active channeling of the warm air between the Plexiglas
layers has been found to be an excellent method of reducing this source of radiant
heat loss. A second wall inside the incubator can maintain a higher temperature
than the outer wall because the cooler nursery air temperature does not affect
the inner wall. In summary, airflow patterns are partially responsible for the
need of an inner wall. Second, we need to look at how the airflow design of
the Giraffe® Incubator can reduce the need for an inner wall. In this new
microenvironment, the effect of warming the hood surface is accomplished through
bi-directional airflow. This reduces the distance that the warm air must travel
in order to heat the hood. The Giraffe® Incubator airflow patterns are directed
up both the side Plexiglas walls. Air returns are relocated to the ends of the
beds. The longest path the air must take to warm the Plexiglas surface is now
half way around the hood instead of all the way around the hood. Third, we validated
the effectiveness of this design in laboratory and clinical conditions. An experiment
was conducted to compare thermal performance inside an GE Healthcare Giraffe
Incubator, GE Healthcare Care Plus® 4000 Incubator, Hill-Rom/Air-Shields
Isolette® Incubator and a Drager 8000 IC Incubator. The experiment measured
the core temperature of an infant simulator when placed in an incubator set
to 37 degrees C. These results showed that the Giraffe® Incubator was comparable
to the Care Plus® 4000 incubator in thermal performance and better than
the Isolette or 8000 IC Incubators. The advantages of eliminating the inner
wall without significant sacrifice in thermal performance are: simplified cleaning,
reduced parts, less attenuation of phototherapy light transmission, and improved
patient visibility.
> 
Can the Giraffe® Incubator be used to transport from labor and delivery
or to the operating room?
If any incubator were properly pre-warmed before being disconnected from power,
the thermal chamber would maintain the internal temperatures for a short period
of time. The magnitude and duration of the integrity of this environment has
not been studied in conventional devices. Currently, most hospitals use pre-warmed
incubators to transport babies within the hospital. Data collected during our
user validation trials showed that thermal stability of an extremely low birthweight
baby was generally preserved if the transit time between power sources was under
10 minutes. Therefore, it is our recommendation that good clinical judgment
should be exercised when transporting an infant in an un-powered warming device.
Of course, the clinician could always consider use of chemical blankets to help
preserve thermal stability during an un-powered transport.
>
What is the best way to admit a baby to the Giraffe® Incubator?
GE Healthcare has developed admission guidelines to support the proper use
of Giraffe® products. The admission guidelines are available on this website
in the “Clinical Practice Guidelines” section.
>
Does the Giraffe® Incubator maintain temperature with both doors
open?
Part of the purpose of the “boost air” curtain is to protect against
entrainment of ambient cool nursery air. Of course, the entrainment becomes
greater with multiple doors and/or portholes open.
>
Has the humidifier been tested to avoid the spread of pseudomonas aeruginosa?
Historically, pseudomonas aeruginosa was the most common pathogen linked to
use of ambient relative humidity. However, there are at least 3 other microorganisms
which are of concern to neonatal caregivers: serratia marcescens, candida albicans,
and eschericia coli. To determine the role of humidity in microbial colonization
of an enclosed micro-environment, laboratory research was conducted on the Giraffe®
products. A Giraffe® humidification system was cleaned with a germicidal
detergent utilizing a dilution of one ounce per gallon of water at the start
of the study (Cavicide, active disinfecting ingredient: diisobutylphenoxyethyl
dimethyl benzyl ammonium chloride). The enclosed micro-environment was run in
air control mode at 35 degrees C and actively humidified at 65% RH through a
servo-controlled mechanism. Sterile, distilled water was added at the start
of the study and as needed to the water reservoir. After reaching temperature
and humidity equilibration, a known inoculum of one of four different micro-organisms
(P. aeruginosa, S. marcesens, E. coli, or C. albicans) reconstituted to 106
to 108 cfu/ml H2O was placed into the reservoir on day 0 and baseline cultures
were obtained. Bacterial cultures were taken at five points including the humidification
reservoir near the immersion heater, the reservoir seal at entry to the Giraffe®,
along the path of airflow at both the east and west doors, and the center of
the mattress. Semi-quantitative bacterial swabs were repeated at 24h, 48h, 72h,
and 168h. The testing of each micro-organism was done serially over a four week
period. Results showed that pseudomonas aeruginosa and candida albicans could
be cultured from the water bath for only up to 24 hours. It was never cultured
at any point that could be accessed by the baby and was never recovered after
24 hours.
>
Is the humidifier reservoir autoclavable?
Yes. The reservoir may also be chemically disinfected. Refer to the operators’
manual that was shipped with the incubator for instructions.
>
Why is the humidifier reservoir so hot?
Risks versus benefits are critical to the decision making process before implementing
any therapeutic intervention such as humidity. The clinician should be guided
by clear evidence that the benefit outweighs the risk. When one considers the
research, it is important to know that as a result of the infectious outbreaks
in the 1950’s and 1960’s, GE Healthcare changed its methodology
of providing micro-environmental humidity. The humidification system with the
Giraffe® Incubator is an immersion heater that sits within a bath of sterile,
distilled water. The temperature of this water bath reaches a temperature of
52 degrees C to 58 degrees C which by itself is bactericidal to most mesophilic
microorganisms (that is, organisms which tend to thrive at human body temperature
and act as pathogens. Therefore, the temperature to which the water bath of
the humidifier was designed to achieve was purposeful. As an added measure of
safety, engineers designed the immersion heater so that a small amount of water
is boiled just before the humidity is disbursed into the air circulation within
the infant compartment. By using this technology, sterile humidity is created
and offered to the infant in a gaseous vapor state, leaving no airborne water
droplets to act as vectors of infectious microorganisms.
>
What is the typical time between refills in the humidifier?
Different environmental conditions, temperature and humidity set points will
determine the length of time between reservoir refills. During user validation
of the Giraffe products, GE Healthcare determined that the reservoir will require
refilling approximately every 12 hours in a 22.5 C environmental temperature,
with a 34 C air temperature set point and a 70% relative humidity set point.
>
When does the Giraffe® Incubator rainout?
The answer to this question depends upon nursery temperature conditions. Under
static laboratory conditions, rainout occurred @ a set point of 75-80% under
ambient test conditions of 23 degrees C, 45% RH. Dynamic testing in nurseries
during our user validation study showed that when the Giraffe was set to 65-70%
RH in typical nursery conditions of 72.7 + 2.2 degrees C (22.5 degrees C), 27.9
+ 12.5% RH, no rainout was documented by the clinicians. Interestingly, it has
been noted that during evaluations in Germany and Sweden, no Giraffe rainout
was noted when the devices were set to 85-90% RH while Drager 8000 IC in the
same nurseries at the very same time had significant rainout. Use of the Giraffe
hood cover should permit the clinician to use even higher levels of humidity
without rainout due to the insulation effect around the Plexiglas hood.
>
Should the “boost air curtain” button always be used for
open door procedures?
In most cases, the answer is yes. However, in philosophies surrounding developmental
care, neutral thermal requirements are different for each baby. Larger babies
may not require the support of the “boost air curtain”. The advantage
of not making the feature automatic, but rather under the control of the clinician
means that the clinician may use their judgment about the infant’s needs
and may also avoid the commonly noted phenomenon of “overshoot”
that has been a historical problem in incubator care.
>
How long does the Giraffe® Incubator operate in boost air mode?
The boost air curtain operates for 20 minutes with clinician activation of
the “boost air curtain” button; 45 minutes when the bed is being
converted from open to closed bed state; 90 minutes when the bed is started
and warmed as an incubator.
>
What effect does swaddling have on “COMFORT ZONE” chart?
The “Comfort Zone” temperature recommendations were developed to
assist the clinicians in making decisions while caring for an infant in air
control mode. The chart was derived from research conducted by Sauer, Dane,
and Visser (1984). This table assumed no swaddling and no added humidification.
However, in a recent study conducted by Mary Short (1998) and funded by Ohmeda
Medical, data suggest that slightly lower air temperature settings (up to 2.9
degrees C) may be required for swaddled babies cared for in air control mode.
While there is little clinical data to support the necessary adjustment in a
humidified environment, consultants available to Ohmeda have suggested that
a reduction in air set temperature may also be necessary if the infant is nursed
in a humidified environment.
>
Can X-rays be taken through the incubator canopy?
Yes. No hardware, longitudinal lines, or holes obstruct a clean x-ray shot.
An x-ray cassette tray is provided to place the cassette without disturbing
the baby. Use the grid pattern to properly position the cassette relative to
the baby. The tray is tucked up very close to the mattress to minimize x-ray
magnification. The in-bed scale contains a central window that will not obstruct
x-rays. Currently, the products do not have exterior aligning markings for the
x-ray cassette. However, the mattress support is made of clear plastic and the
mattress can be raised on one end slightly to see the cassette and position
it properly.
>
How should I use the two temperature probes?
The flexible design of the Giraffe® family of products is such that it
supports use of two temperature probes. Common applications for two temperature
probes include the practices of co-bedding or two-point (tummy-toe differential)
temperature monitoring. If the Giraffe® Incubator is used for co-bedding
twins, two temperature probes should be used. Two probe inputs have been provided
to monitor both babies. The temperature from the probe plugged into jack # 1
will display on the left thermal display, while the temperature from the probe
in jack # 2 will appear in the right upper corner of the graphics accessory
control screen. We recommend constant temperature monitoring of both babies
while co-bedding. Since the Giraffe® products cannot choose which baby to
use for temperature control, the unit will default to air control mode and will
lock out the baby mode when the second probe is inserted. The clinician will
have to determine which infant should guide selection of the air temperature.
The second probe also may be used to measure a second skin temperature on the
same baby, such as “tummy-toe” measurements. Some experts suggest
that a widening gap between the core and peripheral temperature may be an early
marker of infection. Again, air mode must be used whenever two probes are inserted
into the jack panel.
>
Do fitted sheets need to be used for the round mattress?
No, you can use your standard sheets that you currently use as sheets for your
radiant warmer or incubator, but custom fitted sheets are available through
GE Healthcare (part no. 6600-0850-800).
>
| 
