Image 1 : Front view of the Babylog 8000 neonatal ventilator. |
The Babylog 8000™ (Draeger Medical, Telford , PA ) is a neonatal specific ventilator that has been in use for over twenty years. At inception the Babylog was a unique platform providing high-tech applications in regards to breath delivery. This advance technology surpassed the available devices and provided a foundation for present day neonatal ventilators. Even with the success of this ventilator platform there are reasons one may consider trading in their machines.
The rationale for replacing the Babylog is related to technological advances, the lack of upgrade availability, and safety concerns.
- There is no room to expand the pneumatics or software platform; there is no input port that would allow for additional software configuration. Newer ventilators allow for continuous software upgrades.
- The Babylog screen is very small & only displays one waveform at one breath at a time. This making it difficult to analyze waveforms and read alarm messages. Additional monitoring can be provided by mounting a touch screen computer, which runs “VentVieW®” software. Conversely, this is a meager solution since the computer & software is independent of the ventilator. The operator has to turn on each device separately and there is a lag time between the ventilator graphics and the graphics displayed with VentView.
- There are safety concerns in relation to the Babylog’s control knobs. Once a knob is turned the change has been made there is no confirmation process.
- The operator also has to view multiple screens to fine tune ventilator set-points & manipulate expiratory time to change the frequency.
- Another safety concern revolves around emergency air & power sources, this is especially important for areas which are prone to inclement weather. The BabyLog has a short internal battery lasting ~ 20 minutes; an additional external battery is not available and must be purchased from a third party. An air compressor is available however, it is large & cumbersome.
- Tidal Volume Delivery: The accuracy of delivered Vt was perceived to be superior when using the Babylog due to the flow sensor at the patient wye. Conversely, Jaecklin & colleagues showed that all tested neonatal ventilators frequently deliver inaccurate tidal volume [1]. The devices regularly delivered excessive tidal volume in response to sudden increases in compliance or decreases in resistance, potentially putting neonates at risk for barotrauma & volutrauma. New technology is now available, Neurally Adjusted Ventilatory Assist (NAVA) in which the neonate self regulates breath delivery, allowing for the natural lung protective reflexes (Herring-Breur) to terminate the breath, instead of a preset target tidal volume, pressure limit, time-cycle, or flow deceleration criteria.
- Leak compensation: The Babylog can compensate for leaks up to 50% and adjusts the triggering threshold as well as the flow termination criteria automatically to adjust for leaks. When utilizing NAVA, leaks are not an issue since breaths are triggered and terminated based on diaphragmatic impulses.
- Medication delivery: During surfactant and nebulized medication delivery the flow sensor has to be unplugged from the cable and removed from the ventilator circuit. While the flow sensor is out of line the Babylog can only provide a PC-CMV or PC-IMV breath. Continuous breaking of the ventilator circuit may lead to lung de-recruitment and increase the risk for nosocomial infections.
- Modes: One of the Babylog’s popular modes is Pressure Support Volume Guaranteed (PSVG). PSVG is an Adaptive Pressure Control mode in which the operator sets a target tidal volume and the machine will titrate the pressure support to maintain the target tidal volume. This is ideal as long as the patients’ ventilatory demand remains constant. However, this may be problematic in the patient with a very high ventilatory demand. Jaber & colleagues demonstrated with a fixed level of volume guaranteed, an increase in ventilatory demand results in a decrease in pressure support provided by the ventilator, opposite to the desired response [2]. Volume Guaranteed may conceivably result in respiratory distress in the clinical setting. NAVA technology prevents this scenario. NAVA continuously adjusts support based on the patients’ inspiratory drive.
- Expiratory Resistance: The Babylog has the least expiratory resistance compared to other neonatal ventilators tested [3]. Conversely, the Babylog doesn’t have a floating (active) exhalation valve, so the neonate can only end the breath if the time criteria is met or if the flow decelerates to 85% of the peak inspiratory flow (spontaneous breaths). Practitioners who are over concerned with expiratory resistance should focus on how the breath terminates & how this can affect patient ventilator synchrony. In the Babylog mandatory breaths end by meeting a certain time cycle. During spontaneous breaths the breath will terminate 1st due to flow deceleration criteria & second a time criteria if a large leak is present. The flow termination criteria is 15% (85% of the peak inspiratory flow), which cannot be changed, if a large leak is present this results in cycling asynchrony. In regards to NAVA you do not have cycle asynchronies associated with leaks, flow termination criteria, and/or timing. In NAVA the breath termination is determined by the patient.
[1]. Jaecklin, T. et. Al. (2007). Volume-Targeted Modes of Modern Neonatal Ventilators: How Stable is the Delivered Tidal Volume? Intensive Care Medicine. 33 (11): 326-335.
[2]. Jaber, S. et. Al. (2005). Volume-Guaranteed Pressure-Support Ventilation Facing Acute Changes in Ventilatory Demand. Intensive Care Medicine. 31: 1181-1188.
[3]. Di Blasi, R. et. Al. (2008). The Impact of Imposed Expiratory Resistance in Neonatal Mechanical Ventilation: a Laboratory Evaluation. Respiratory Care. 53 (11): 1450-1460.