High Frequency Oscillatory Ventilation Combined With Intermittent Sigh Breaths: Effects on Blood Oxygenation and Stability of Oxygenation

Summary

Background:

Ventilator induced lung injury (VILI) remains a problem in neonatology. High frequency oscillatory ventilation (HFOV) provides effective gas exchange with minimal pressure fluctuation around a continuous distending pressure and therefore small tidal volume. Animal studies showed that recruitment and maintenance of functional residual capacity (FRC) during HFOV ("open lung concept") could reduce lung injury.

"Open lung HFOV" is achieved by delivering a moderate high mean airway pressure (MAP) using oxygenation as a guide of lung recruitment. Some neonatologists suggest combining HFOV with recurrent sigh-breaths (HFOV-sigh) delivered as modified conventional ventilator-breaths at a rate of 3/min. The clinical observation is that HFOV-sigh leads to more stable oxygenation, quicker weaning and shorter ventilation. This may be related to improved lung recruitment. This has however to our knowledge not been tested in a clinical trial using modern ventilators.

Purpose, aims:

* To compare HFOV-sigh with HFOV-only and determine if there is a difference in oxygenation expressed as a/A-ratio and/or stability of oxygenation expressed as percentage time with oxygen saturation outside the reference range.
* To provide information on feasibility and treatment effect of HFOV-sigh to assist planning larger studies. We hypothesize that oxygenation is better during HFOV-sigh.

Methods:

Infants at 24-36 weeks corrected gestational age already on HFOV are eligible. Patients will be randomly assigned to HFOV-sigh (3 breaths/min) followed by HFOV-only or vice versa for 4 alternating 1-hours periods (2-treatment, double crossover design, each patient being its own control). During HFOV-sigh set-pressure will be reduced to keep MAP constant, otherwise HFOV will remain at pretrial settings. Outcome will be calculated from normal clinical parameters including pulx-oximetry and transcutaneous monitoring of oxygen and carbon-dioxide partial pressures.

Conditions

• Respiratory Distress Syndrome, Newborn
• Bronchopulmonary Dysplasia
• Ventilator Induced Lung Injury

Interventions

OTHER

HFOV combined with sigh breaths

We plan only to investigate infants already ventilated on the HFOV-modus on high frequency oscillators, where the HFOV modus can be superimposed on conventional modes of ventilation. This gives the opportunity to combine HFOV with intermittent sigh breaths with a pre-set frequency and pre-set peak inspiratory pressure (PIP) and thus comparing HFOV combined with sigh breaths (HFOV-sigh) with conventional HFOV (HFOV-only). All included participants will be exposed to the two different ventilator strategies tested in this trial, albeit in alternating and different order. Each patient will serve, as it's own control. The trial will involve four alternating 1-hours periods allowing a sufficient "wash-out" period, as it has been shown that alveolar recruitment and derecruitment may take up to 25 min after changes to ventilator pressures At study start the patients will randomly be assigned to either starting with HFOV-only or HFOV-sigh

Sponsors & Collaborators

• Rigshospitalet, Denmark

  lead OTHER

Principal Investigators

• Christian Heiring, md · Rigshospitalet, Denmark

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

NONE

Model

CROSSOVER

Eligibility

Min Age

24 Weeks

Max Age

44 Weeks

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2014-08-31

Primary Completion

2022-06-30

Completion

2022-06-30

Countries

• Denmark

Study Locations