Respiratory muscle function in the newborn: a narrative review

Abstract

Our aim was to summarise the current evidence and methods used to assess respiratory muscle function in the newborn, focusing on current and future potential clinical applications. The respiratory muscles undertake the work of breathing and consist mainly of the diaphragm, which in the newborn is prone to dysfunction due to lower muscle mass, flattened shape and decreased content of fatigue-resistant muscle fibres. Premature infants are prone to diaphragmatic dysfunction due to limited reserves and limited capacity to generate force and avoid fatigue. Methods to assess the respiratory muscles in the newborn include electromyography, maximal respiratory pressures, assessment for thoraco-abdominal asynchrony and composite indices, such as the pressure–time product and the tension time index. Recently, there has been significant interest and a growing body of research in assessing respiratory muscle function using bedside ultrasonography. Neurally adjusted ventilator assist is a novel ventilation mode, where the level of the respiratory support is determined by the diaphragmatic electrical activity. Prolonged mechanical ventilation, hypercapnia and hypoxia, congenital anomalies and systemic or respiratory infection can negatively impact respiratory muscle function in the newborn, while caffeine and synchronised or volume-targeted ventilation have a positive effect on respiratory muscle function compared to conventional, non-triggered or pressure-limited ventilation, respectively. Impact Respiratory muscle function is impaired in prematurely born neonates and infants with congenital anomalies, such as congenital diaphragmatic hernia. Respiratory muscle function is negatively affected by prolonged ventilation and infection and positively affected by caffeine and synchronised compared to non-synchronised ventilation modes. Point-of-care diaphragmatic ultrasound and neurally adjusted ventilator assist are recent diagnostic and therapeutic technological developments with significant clinical applicability.

Diaphragmatic electromyography during a spontaneous breathing trial to predict extubation failure in preterm infants

“…Some previous studies have reported a higher PMA to be predictive of extubation failure, 8 with the authors suggesting that it is the prolonged period of ventilation prior to extubation that causes disuse atrophy of the diaphragm and thus subsequent extubation failure. 7 , 45 Within our study, there was no difference, however, in the duration of invasive mechanical ventilation prior to extubation between those who were successfully extubated and those infants who were not. Indeed, our finding that a higher PMA is associated with successful extubation has been demonstrated in other previous studies and may also be linked to such infants having greater brain maturity, the development of which is crucial in controlling and regulating breathing.…”

Ultrasonography in Assessment of Respiratory Muscles Function: A Systematic Review

“…From this perspective, US measurements will rather supplement than replace pulmonary function assessment. At present, US measurements are useful (i) in assessing diaphragm dysfunction (paralysis [37], asymmetrical movements [55], congenital anomalies [56]) or (ii) as a prognostic marker for frequent exacerbations in COPD patients [32]. It is also worth considering US measurements of the diaphragm in surgical management/repair of congenital diaphragmatic hernia [57][58][59] and as an additional indicator in the assessment of effort tolerance in pulmonary rehabilitation or rehabilitation progress [60].…”

Adaptive Triboelectric Nanogenerators for Long-Term Self-Treatment: A Review

“…Loss of muscle function can lead to many diseases, including stroke, spinal cord injury, and multiple sclerosis [ 75 , 76 ]. Electrical stimulation has positive effects when treating this disease.…”