Highlights of the Baby Log infant ventilator

By Elizabeth Kelley Buzbee AAS, RRT-NPS, RCP

Kingwood College Respiratory Care Department

Reference:

·        Whitaker's Comprehensive Neonatal Pediatric Respiratory Care: page 529-532

·        Cairo's Respiratory Care equipment : page 593-598

·        Czervinske’s Neonatal Pediatric Respiratory Care  page 257-260

 

What is the Drager Baby Log?

It is a neonatal/pediatric ventilator designed for children up to 20 kg.

  1. Microprocessor controlled
  2. Pressure limited
  3. Time-cycled
  4. Continuous flow

 

What kind of modes does this ventilator have?

  1. CPAP
  2. A/C
  3. SIMV or IMV [with flow sensor removed]
  4. PS [please note that the Baby Log does not at this time do SIMV + PS.
  5. Volume guarantee* [preset Vt on each supported breath regardless of effort or C.]

*Volume guarantee is a mechanical ventilatory mode in which the RCP sets a PS but also sets a volume based on the pressure/volume ratio of the actual breaths. [Refer: PRVC by Todd Loftus 2003]

 

"Pressure Regulated Volume Control is really pressure controlled breaths with an automatically adjusted pressure control level similar to Volume Support. A target tidal volume is set and the pressure level changes as needed to provide the target volume.

 

In both Volume Support and PRVC, the pressure level may not go any higher than 5 cm H20 below the Upper Pressure Limit."

 [Reference:  http://www.kumc.edu/SAH/resp_care/300.html U of Kansas]

 

 

What kind of ranges can this ventilator achieve?

  1. Breath rates between 1 bpm and 150 bpm
  2. Pressure ranges between 10-80 cmH20
  3. Ti from .1 second to 2 seconds
  4. Te from .2 to 30 seconds
  5. Vt range from 2 ml to 100 ml
  6. PEEP 0-25 cmH20
  7. Inspiratory and expiratory flow rates from 1 to 30 lpm

 

How does this ventilator measure volume?

At the patient wye, there is a heated wire anemometer**.  Because it measures at the endotracheal tube, the volume measurement is quite accurate.  This machine can measure inspired Vt and expired Vt and display the amount of leak as a ‘percent leak.'

 

**Heated wire anemometer: According to page 228 of Branson’s this device actually measures flow rate by the amount of electricity needed to keep the wire heated. As flow increase, the wire cools and the heater works harder. Needless to say, these work best when they aren't subjected to turbulent flow and to water on the probe.

 

The Flow sensor is required for many actions

1.         It’s not too surprising that the flow sensor is required for the following modes: SIMV, PSV & A/C. Turning the selector knob to those settings is just not enough to get the patient to trigger breaths. You must add the flow sensor and calibrate it.

 

2.         The Ve alarm, Ve and Vt indicators will not work without the flow sensor because the volumes are measured by that device.

 

3.         The C and the RAW indictors need the volume before they can display correct information, so these parameters also need a calibrated flow sensor inline.

 

What else can this Baby Log do?

 

What kinds of alarms are set automatically?

To set the automatic alarms, you must select the Confirm after each ventilator change. Failure to do so will result in the ventilator maintaining the last alarm settings.

[PIP - PEEP]         +  PEEP

4                   

What alarms must the RCP set?

 

What do the dial panels control? And how do you make changes?

 If a parameter needs attention, its LED will blink green.

 

What do the soft-keys control?

·        The Waveforms on the screen displays: pressure or flow/time

 

·        MEASURED VALUES window digitally displays Ve, Fi02, PIP, PAW, and PEEP.

 

 

·        The STATUS key displays the mode of ventilation

 

·        MENU keys at the bottom

 

 

·        The MANUAL soft key triggers a manual breath.

 

What happens if excessive pressure rises?

Exhalation valve opens and vents excessive pressure.

 

What is the message log?

A record of the time of occurrence, this log shows the displayed text and response for the last 100 messages.

 

What is the VIVE?

The variable inspiratory variable expiratory flow is an option for continuous flow in which the inspiratory and expiratory flows can differ between inspiration & exhalation.

 

There is a venturi in the exhalation limb to prevent auto-PEEP with high expiratory flows. Remember that in the face of excessive flow rate, the neonatal circuit is subject to becoming a flow resistor PEEP device due to its narrow lumen, high Resistance and the relatively small exhalation port

 

What triggers inspiration in the A/C mode?

The Baby log is flow-sensitive, but it also senses spont volume. If the lowest sensitivity is selected, there will be a flow of .25 Lpm before it will trigger.

 

Settings above 1 on the sensitivity will result in the machine sensing the flow but waiting for a bit of volume to move before it triggers.

 

What happens in IMV?

While the IMV breath is pressure-targeted and time-triggered and pressure or flow-limited, the patient breaths off the continuous flow during the spontaneous breaths.  If the flow-sensor is added, one can safely change to the SIMV mode.

 

What must be we do to use Nasal CPAP on the Baby Log?

You must disable the flow measurement by disconnecting the flow sensor and pressing SET/CHECK button.

 

In CPAP, the RCP selects Fi02, inspiratory flow and PEEP

 

How does the Baby Log calibrate the 02 analyzer?

The 02 analyzer calibrates itself every 24 hours, but you can select CAL from the FUNCTION menu.

 

 

How do we calibrate the flow sensor?

Must be done each time the ventilator is set up, or if the sensor is replaced or seems to be malfunctioning.  Follow the prompts on the screen.

1.      turn power on in the back upper right hand corner of the machine

 

2.      select Cal, the select flow & Start

 

 

 

 

What does the panel look like?