Optimising mechanical ventilation in newborns using capnography
Research type
Research Study
Full title
Optimising mechanical ventilation in newborns using capnography
IRAS ID
248018
Contact name
Anne Greenough
Contact email
Sponsor organisation
King's College London
Duration of Study in the UK
1 years, 11 months, 3 days
Research summary
Research Summary
Seven percent of all infants are born prematurely and many require respiratory support in the new-born period. Mechanical ventilation can be life-saving, but unfortunately is associated with long term complications. The most common adverse outcome of premature birth is chronic respiratory morbidity including bronchopulmonary dysplasia (BPD). Prematurely born infants may also suffer intraventricular haemorrhage (IVH) and periventricular leukomalacia (PVL) which result in adverse neurodevelopmental outcome at follow-up, including cerebral palsy. Those complications are increased in infants who have suffered abnormalities in carbon dioxide (CO2) levels and indeed such abnormalities can also result in adverse neurodevelopmental outcomes in infants born at term. It is thus essential, if the outcomes of infants requiring respiratory support in the newborn period are to be improved, carbon dioxide levels are more appropriately monitored. In the proposed research, we will investigate whether real time, continuous capnography (non-invasive assessment of CO2 levels) will allow earlier detection of acute complications in mechanically ventilated infants, such as a blocked or dislodged endotracheal tube or a pneumothorax and reduce the average daily frequency of invasive blood sampling which results in anaemia and hence associated complications related to blood transfusions. We also aim to accurately calculate the anatomical and alveolar dead space in infants with various neonatal respiratory diseases using real time monitoring by capnography and hence appropriate tidal volumes will be delivered. Reducing the delivery of inappropriately high or low tidal volumes, we hypothesise will reduce the development of serious complications such as BPD, IVH and PVL. We will determine whether the results of the novel technique of low sampling rate, side-stream capnography incorporated in ventilator software will correlate with the results of low dead space mainstream capnography and arterial blood gas CO2 measurements. In addition, we will determine if using the results of the novel technique of continuous side stream capnography to automatically adjust ventilator settings will reduce the incidence of hypocarbia and hypercarbia and associated complications.Summary of Results
Continuous monitoring of carbon dioxide (CO2) levels can be achieved by capnography with the novel side-stream capnograph device performing similarly to the gold standard mainstream capnograph. The poorer correlation of end-tidal to arterial carbon dioxide levels in infants with severe respiratory disease should highlight to clinicians increased ventilation-perfusion mismatch. Furthermore, continuous end-tidal capnography monitoring in ventilated infants was associated with a reduction in the degree of the magnitude of difference in CO2 levels and highest level of CO2 on the first day after birth.Finally, capnography can be utilised to non-invasively calculate the dead space - that part of the lungs which receives ventilation but is not perfused. Measurement of the dead space was feasible in ventilated new-born infants. The dead space (per kilogram) was higher in ventilated infants with respiratory distress syndrome or evolving bronchopulmonary dysplasia compared to term controls without respiratory disease. The dead space volume should be considered when calculating the most appropriate volume during volume-targeted ventilation.
REC name
London - Camden & Kings Cross Research Ethics Committee
REC reference
18/LO/1602
Date of REC Opinion
14 Nov 2018
REC opinion
Further Information Favourable Opinion