2004 OPEN FORUM Abstracts
THE EFFECT OF RADIANT WARMER/ISOLETTE HEATERS ON HUMIDIFIER TEMPERATURE AND TEMPERATURE PROBE.
Stephen G. Staib RRT. Hahnemann University Hospital, Neonatal Intensive
Care Unit
Background: It has been stated that there is an adverse effect on the
humidifier temperature when the temperature probe is placed within the
radiant warmer bed or placed inside an isolette. This was a bench study
devised to test that statement. Objective: To determine if there is any
change in patient skin temperature, humidifier temperature, and humidifier
chamber temperature when the temperature probe is placed in the center
of the radiant warmer and when placed inside the isolette. Materials:
Bird VIP ventilator with neonatal ventilator tubing, Fisher-Paykel MR730
humidifier with temperature probe and continuous water feed chamber,
Airshields IICS90 radiant warmer with skin probe, Airshields isolette
infant incubator C100, Sensormedics 3100A high frequency oscillator,
and a 50cc anesthesia bag to simulate a patient.
Methods: In a room chosen
to maintain the same environment for the study, the equipment was set
up to mimic a patient on a neonatal ventilator and oscillator. The ventilator
was set up so that the temperature probe was centered on the warmer bed
and isolette. The warmer and isolette was set up to provide a skin temperature
of at least 36ºC with the skin probe attached to the anesthesia
bag. The VIP was set as follows; SIMV, f=20bpm, Ti .35seconds, flow 10
Lpm, peak pressure 20cm, positive end expiratory pressure 5cm, FIO2 1.0,
and the humidifier were set at 36ºC. The ventilators were set at
the top of the warmer (not the side) and allowed to run for 8 hours a
day for 7 days. Measurements of skin temperature, humidifier temperature,
and chamber temperature every 30 min and recorded. One 8-h day was used
to incorporate plastic wrap that is used to maintain the body temperature
of the infants (stretched form the side partitions of the warmer). One
8-hour test day was used to determine the effects of a temperature probe
attached to the high frequency oscillator Ventilator (HFOV) with the
settings of Ti% 33, HZ 15.0, ? p 15.0cm, power 2.0, map 12cm, and bias
flow at 20Lpm (these settings were based on a patient currently on HFOV.)
Results: Warmer temperature ranged from 35.5º-36.5ºC in all
ventilator and oscillator test days. Humidifier temperature ranged from
35.8º-36.8º C on all test days. Chamber temperature ranged
from 34.0º-36.1ºC in all ventilator test days and 33.9º-34.7ºC.
Conclusion: 1) There was no significant effect on the temperature of
the humidifier by either the radiant warmer or the isolette. 2) This
shows that the temperature probe can be placed anywhere near the patient
and the humidifier will adjust the chamber temperature to provide the
set temperature. 3) The position of the temperature probe can be positioned
anywhere in the warmer or isolette to allow proper nursing care. 4) While
the study was going on, there were other patients in the NICU on the
same neonatal ventilator and oscillator that was observed to have significant
rainout compared to the study ventilators. (The temperature probes of
these ventilators were located outside the radiant warmers and isolettes)
Example; there was 300cc’s of condensation drained from the oscillator
patient (measured by syringe) during the same eight-hour period the HFOV
study was going on which yielded 30cc of condensation.