Gusztav Belteki1, Colin J Morley1.
Abstract
OBJECTIVE: High-frequency oscillatory ventilation (HFOV) is widely used in neonatology. The Dräger Babylog VN500 ventilator offers volume-guaranteed HFOV (HFOV-VG) mode when the high-frequency tidal volume (VThf) to be delivered can be set. We investigated how HFOV-VG maintains VThf in the short and longer term and how it affects other ventilator parameters and blood gases.
METHODS: We downloaded ~3.2 million seconds (36.7 days) of ventilator data from 17 infants ventilated using HFOV-VG during clinical care with 1 Hz sampling rate. To process and analyse the data, we used the Python computer language.
RESULTS: Overall, the median VThf was 1.93 mL/kg (IQR 1.64-2.45 mL/kg). The difference between set and delivered tidal volume was <0.2 mL/kg for 83% of time. In the individual recordings, the median VThf ranged between 1.44 and 3.31 mL/kg. During HFOV-VG, the VThf varied from 1 second to another, but it was very close to the target value when averaged over 5 min periods. After weight correction, the VThf or the diffusion coefficient of carbon dioxide (DCO2) showed weak inverse correlation with partial pressure of CO2(pCO2) (for VThf, r=-0.162, 95% CI -0.282 to -0.037, p=0.01). Uncorrected values showed no correlation. Of the 53 blood gas measurements taken when VThf was >2.5 mL/kg, there were only six (11%) with a pCO2 >8 kPa.
CONCLUSIONS: During HFOV-VG, the tidal volume of oscillations varies in the short term but is maintained very close to the target over the longer term. VThf or DCO2 have poor correlation with CO2 levels but a volume of >2.5 mL/kg VThf is rarely needed. © Author(s) (or their employer(s)) 2019. No commercial re-use. See rights and permissions. Published by BMJ.
OBJECTIVE: High-frequency oscillatory ventilation (HFOV) is widely used in neonatology. The Dräger Babylog VN500 ventilator offers volume-guaranteed HFOV (HFOV-VG) mode when the high-frequency tidal volume (VThf) to be delivered can be set. We investigated how HFOV-VG maintains VThf in the short and longer term and how it affects other ventilator parameters and blood gases.
METHODS: We downloaded ~3.2 million seconds (36.7 days) of ventilator data from 17 infants ventilated using HFOV-VG during clinical care with 1 Hz sampling rate. To process and analyse the data, we used the Python computer language.
RESULTS: Overall, the median VThf was 1.93 mL/kg (IQR 1.64-2.45 mL/kg). The difference between set and delivered tidal volume was <0.2 mL/kg for 83% of time. In the individual recordings, the median VThf ranged between 1.44 and 3.31 mL/kg. During HFOV-VG, the VThf varied from 1 second to another, but it was very close to the target value when averaged over 5 min periods. After weight correction, the VThf or the diffusion coefficient of carbon dioxide (DCO2) showed weak inverse correlation with partial pressure of CO2(pCO2) (for VThf, r=-0.162, 95% CI -0.282 to -0.037, p=0.01). Uncorrected values showed no correlation. Of the 53 blood gas measurements taken when VThf was >2.5 mL/kg, there were only six (11%) with a pCO2 >8 kPa.
CONCLUSIONS: During HFOV-VG, the tidal volume of oscillations varies in the short term but is maintained very close to the target over the longer term. VThf or DCO2 have poor correlation with CO2 levels but a volume of >2.5 mL/kg VThf is rarely needed. © Author(s) (or their employer(s)) 2019. No commercial re-use. See rights and permissions. Published by BMJ.
Entities:
Keywords:
Hfov; Mechanical Ventilation; Neonatology; Volume-targeted Ventilation
Mesh:
Year: 2018
PMID: 30217870 DOI: 10.1136/archdischild-2018-315490
Source DB: PubMed Journal: Arch Dis Child Fetal Neonatal Ed ISSN: 1359-2998 Impact factor: 5.747