Challenging Traditional Rib Counting in Neonatal Respiratory Care

Neonatal respiratory disease encompasses a wide diversity of pathologies, and this heterogeneity presents a challenge when providing respiratory support modalities. Ventilatory strategies have the common goal of optimizing lung volume to adequately ventilate and oxygenate newborns while also limiting barotrauma and volutrauma. Over the last 2 decades, there has been a substantial shift from endotracheal mechanical ventilation to various modalities of noninvasive ventilation, especially in the preterm population. However, regardless of ventilatory mode, there are real risks, from atelectasis to hyperinflation, contributed to by multiple developmental factors such as pulmonary heterogeneity, surfactant deficiency, and a compliant neonatal chest wall. Traditionally, the neonatal intensivist uses pulse oximetry and blood gas status as indirect markers of an underexpanded or overexpanded lung. Additionally, modern ventilators offer refined graphs and trend views for displaying changing pulmonary mechanics. Indeed, clinical acumen remains both art and science when evaluating the totality of a newborn’s physical examination within the context of their evolving lung disease and resultant oxygenation and ventilation status. Still, the bedside chest radiograph remains one of the most used backup investigations should an infant’s respiratory status change or when the need arises to further evaluate substantive changes in ventilator settings. Until now, much weight is attributed to the rib count and the position of the diaphragm on plain radiograph films as a measure of lung inflation. Ventilator settings are still regularly being adjusted based on radiograph images. The accompanying article by Dahm and colleagues informs us that these radiograph images may have been misinterpreted far too often and that a better backup plan may be needed to estimate and optimize lung volume as part of a neonatal respiratory support strategy.