Evaluation of bedside pulmonary function in the neonate: From the past to the future

Abstract

Pulmonary function testing and monitoring plays an important role in the respiratory management of neonates. A noninvasive and complete bedside evaluation of the respiratory status is especially useful in critically ill neonates to assess disease severity and resolution and the response to pharmacological interventions as well as to guide mechanical respiratory support. Besides traditional tools to assess pulmonary gas exchage such as arterial or transcutaenous blood gas analysis, pulse oximetry, and capnography, additional valuable information about global lung function is provided through measurement of pulmonary mechanics and volumes. This has now been aided by commercially available computerized pulmonary function testing systems, respiratory monitors, and modern ventilators with integrated pulmonary function readouts. In an attempt to apply easy-to-use pulmonary function testing methods which do not interfere with the infant́s airflow, other tools have been developed such as respiratory inductance plethysmography, and more recently, electromagnetic and optoelectronic plethysmography, electrical impedance tomography, and electrical impedance segmentography. These alternative technologies allow not only global, but also regional and dynamic evaluations of lung ventilation. Although these methods have proven their usefulness for research applications, they are not yet broadly used in a routine clinical setting. This review will give a historical and clinical overview of different bedside methods to assess and monitor pulmonary function and evaluate the potential clinical usefulness of such methods with an outlook into future directions in neonatal respiratory diagnostics.

Electromagnetic inductance plethysmography is well suited to measure tidal breathing in infants

“…This allows extended recordings in babies who are respiratory unstable or use equipment that may preclude the use of a facemask, primarily continuous positive airway pressure (CPAP) or high-flow nasal cannulas (HFNCs). In accordance with previous studies, we found that applying a facemask significantly increased minute ventilation [2, 4, 7]. This finding is physiologically plausible and most likely explained by increased dead space ventilation induced by the facemask or by tactile stimulation of the facial skin.…”

“…Tidal breathing measurements and monitoring provide valuable information about lung function in infants, and can be used to evaluate lung development and management of respiratory diseases [1, 2]. However, these measurements are currently largely used as research tools because most techniques are complex and time-consuming, require sedation, or involve the application of a facemask that adds dead space and alters the breathing pattern of the infant [1, 3–6].…”

“…It does not require sedation, and allows for continuous and prolonged recording of respiratory data without using a facemask. EIP can be seen as an extension of respiratory inductance plethysmography (RIP), a validated technique that has been available for decades [2, 7, 8]. The clinical use of RIP has been limited by complex calibration procedures, in contrast to EIP, which allows for simple and patient-independent calibration.…”

Basic principles of respiratory function monitoring in ventilated newborns: A review

“…Regardless of ventilation mode, careful monitoring of respiratory function during mechanical ventilation remains essential. Respiratory function monitoring, together with clinical, radiological, and blood gas monitoring, has been found to reduce mortality and morbidity in ventilated infants, and is essential for adjusting ventilator parameters to achieve optimal gas exchange and to assess patient status and outcomes of therapeutic interventions [7][8][9] .…”

Optoelectronic Plethysmography in Clinical Practice and Research: A Review

“…Typically, an easier marker protocol (24 markers on the anterior thoraco-abdominal surface) is used for such analysis. The non-invasive bedside evaluation of the respiratory status with OEP is especially useful in critically ill neonates to assess disease severity and the response to pharmacological interventions [63] as well as to guide mechanical respiratory support (e.g., high-frequency oscillatory ventilation) [64] .…”