The Effects of High Frequency Oscillatory Ventilation (HFOV) with Volume Guarantee (VG) on Left Ventricular Function, Systemic and Regional Oxygenation, and Ventilation When Compared to HFOV and Conventional Mechanical Ventilation (CMV) in A Newborn Piglet Model of Respiratory Distress Syndrome (RDS)
Bibliographic record
Abstract
Abstract BACKGROUND: RDS due to surfactant deficiency is commonly seen in preterm infants. These infants often require ventilatory support such as CMV and HFOV. HFOV with VG (HFOV+VG) is an alternative mode that delivers a set tidal volume. There is limited data on either HFOV mode regarding the effects on left ventricular (LV) function, systemic and regional oxygenation, and ventilation. OBJECTIVES: We primarily compared the effects of CMV with VG, HFOV, and HFOV+VG on cardiac index (CI). Secondary parameters included heart rate (HR), mean arterial pressure (MAP), LV ejection fraction (EF), stroke volume (SV), dP/dt max, LV end-systolic volume and pressure (ESV, ESP), end-diastolic volume and pressure (EDV, EDP), and measures of oxygenation and ventilation. Oxygenation parameters included cerebral and renal near-infrared spectroscopy (NIRS), partial pressure of arterial oxygen (PaO2), and carotid artery flow index (CAFI). Ventilation parameters included partial pressure of arterial carbon dioxide (PaCO2) and minute ventilation (MV). DESIGN/METHODS: Piglets (1.4-2.4 kg; 1-3 days old) were acutely anesthetized and instrumented with the placement of a right femoral arterial catheter for blood gas analysis, NIRS probes (Invos®), Transonic® flow probe on right common carotid artery, and Millar® catheter in the LV. Warm saline lung lavage was performed to achieve an AaDO2 of 300-450 mmHg to simulate moderate to severe RDS. Piglets were then block-randomized to CMV, HFOV or HFOV+VG for 4 hours using a Fabian HFO ventilator (Acutronic Medical Systems AG, Switzerland)(n=8 per group). Sham-operated piglets without RDS were monitored for the same duration under CMV (n=6). Two-way repeated measures ANOVA was used to analyze the data between modes or time points. RESULTS: Piglets developed moderately severe RDS with comparable AaDO2 and Paw along with stable hemodynamic parameters. Both HFOV and HFOV+VG groups had similar PaCO2 whereas the CMV group had elevated PaCO2 when compared to that of the Sham (p<0.01). Switching to HFOV resulted in a higher MV than its baseline. HFOV+VG but not HFOV or CMV groups had lower regional oxygenation and CAFI than its respective normoxic baseline (all p<0.01). HFOV and HFOV+VG had higher CI, EF, and SV than CMV at 4 hours of recovery (p<0.05) with similar HR, MAP, dP/dt max, ESV, ESP, EDV and EDP. CONCLUSION: In our piglet model of RDS, HFOV shows benefits to LV function and ventilation when compared to CMV. HFOV+VG does not show benefits compared to HFOV.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.002 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".