SensorMedics high-frequency oscillatory ventilator
The SensorMedics High-Frequency Oscillatory Ventilator is a patented high-frequency (>150 Rf) mechanical ventilator designed and manufactured by SensorMedics Corp. of Yorba Linda, California. After a series of acquisitions, Vyaire Medical, Inc. marketed the product as 3100A/B HFOV Ventilators.[1] Model 3100 (later 3100A) received premarket approval from the United States Food and Drug Administration (FDA) in 1991 for treatment of all forms of respiratory failure in neonatal patients.[2] In 1995, it received pre-market approved for Pediatric Application with no upper weight limit for treating selected patients failing on conventional ventilation.
3100A[edit]
The 3100A model is used for infants and children under 35 kilograms (<35 kg).[3]
3100B[edit]
The 3100B model is used for all other people weighing more than 35 kilograms.[3]
Controls and settings[edit]
Bias flow[edit]
Adjusting bias flow affects mean Paw. Lowering bias flow may decrease the work of breathing and facilitate weaning.
- Typical ranges
- Premature 8–15 LPM
- Near-term 10–20 LPM
- Small child 15–25 LPM
- Large Child 20–30 LPM
Adjust[edit]
This control sets the mean airway pressure, directly affecting lung volume and oxygenation.
The initial setting is slightly higher than the mean airway pressure for conventional ventilation.
Power[edit]
Piston displacement is controlled by the power setting. Power changes ventilation and thereby changes blood PaCO2 levels.
- Typical values
Start with a power of 2.0 and adjust for chest wiggle to the umbilicus.
Inspiratory time %[edit]
Ti% is the percentage of time allotted for inspiration. Once this value is set, it rarely needs to be changed.
- Typical values
- 33% is recommended by the manufacturer for almost all applications.
- Up to 50% is recommended in situations where lung recruitment is necessary.
- Any Inspiratory Time above 33% can cause air trapping and lead to barotrauma. Setting the Mean airway pressure 1–2 cm of h2O above the set MAP for a few minutes, then weaning back down to the original MAP can recruit alveoli safely.
Frequency[edit]
Frequency (Rf) is the number of breaths in one second, expressed in hertz (hz). One hertz is equal to 60 breaths per minute (Rf) .
- Typical values and ranges
- The smaller the patient, the higher the frequency.
- The larger the patient, the lower the frequency.
- Changes in frequency
- Decrease in frequency = increased tidal volume.
- Increase in frequency = decreased tidal volume.
Problems[edit]
Since neither the 3100A or the 3100B measure actual tidal volumes, it is impossible to wean with precision;[4] as a result, some clinicians find it problematic to use these machines for oscillatory ventilation.[4]
References[edit]
- ^ "3100A/B HFOV Ventilators". Vyaire Medical. Retrieved 6 July 2020.
- ^ "Premarket Approval (PMA)". www.accessdata.fda.gov. Retrieved 6 July 2020.
- ^ a b Custer JW, Ahmed A, Kaczka DW, Mulreany DG, Hager DN, Simon BA, et al. (2011). "In vitro performance comparison of the Sensormedics 3100A and B high-frequency oscillatory ventilators". Pediatric Critical Care Medicine. 12 (4): e176–80. doi:10.1097/PCC.0b013e3181fe3028. PMID 21037502. S2CID 205929354.
- ^ a b Scott CJ, McGeorge AD, Hancock SW (1997). "Failure of adequate ventilation using Sensormedics 3100A High Frequency Oscillatory Ventilator". Paediatr Anaesth. 7 (5): 432. PMID 9308072.