A study published in Pediatric Research reports that mesenteric blood flow—the circulation supplying the intestine—was similarly compromised in preterm neonates receiving either continuous positive airway pressure, or CPAP, or high-flow respiratory support. The finding challenges a common assumption that high-flow therapy may impose a substantially different circulatory burden on the immature gut than CPAP. In premature infants, respiratory support is often essential because the lungs are structurally and functionally underdeveloped. Yet the pressure, airflow and changes in intrathoracic physiology created by that support can influence blood flow beyond the lungs, including in the gastrointestinal tract. The research by K. Rajay and G. Toldi draws attention to a vulnerable connection between neonatal respiratory care and intestinal oxygen delivery, an issue of particular importance because preterm infants are already at increased risk of feeding intolerance and serious intestinal disease.
CPAP and high-flow nasal support are widely used to help premature infants breathe without placing them on invasive mechanical ventilation. CPAP delivers a continuous level of positive pressure that helps prevent the small airways and alveoli from collapsing at the end of expiration. By keeping more lung tissue open, it can improve oxygen exchange and reduce the work of breathing. High-flow therapy, in contrast, delivers warmed and humidified gas through nasal cannulae at relatively high flow rates. Its physiological effects depend on the flow, the infant’s size, the fit of the nasal interface and how freely air can escape through the mouth and nose. Although high-flow support is often perceived as gentler, it can still generate positive airway pressure and alter the mechanics of breathing. Both approaches therefore have the potential to affect pressures inside the chest and abdomen, which may influence circulation to abdominal organs.
The mesenteric circulation is the vascular network that supplies the stomach, intestines and associated digestive organs. Its role extends well beyond digestion: the intestine requires a continuous supply of oxygen and nutrients to maintain the intestinal barrier, support movement and absorb nutrients. In a preterm infant, this system is still developing. Blood vessels may have limited capacity to adapt rapidly to changes in pressure or oxygen demand, while the heart has a restricted ability to increase output when the circulation is challenged. A reduction in intestinal blood flow does not automatically result in injury, but sustained or repeated reductions may make the bowel less resilient. This is one reason clinicians monitor abdominal signs, feeding tolerance and systemic circulation closely when caring for extremely premature newborns.
The study’s central message is not that either CPAP or high-flow support should be abandoned. Rather, it indicates that both forms of non-invasive respiratory assistance may be associated with a comparable reduction in mesenteric blood flow. The distinction matters because treatment decisions are often influenced by expectations about side effects and physiological burden. If one method were consistently shown to preserve intestinal perfusion better than the other, that information could become an additional factor in choosing respiratory support. The reported result suggests that the relationship is more complex. The intestine may respond not simply to the label attached to the respiratory device, but to the total physiological environment created by respiratory pressure, blood-gas changes, cardiac performance, fluid status and the infant’s stage of development.
One possible mechanism involves the effects of positive pressure on venous return. Pressure within the chest can influence how much blood returns to the heart, while pressure changes in the abdomen may affect the resistance faced by blood flowing through the intestinal circulation. If cardiac output or arterial pressure falls, the body may redirect blood toward organs considered immediately vital, potentially reducing intestinal perfusion. Respiratory support can also change carbon dioxide levels and oxygenation, both of which influence vascular tone. The intestine is not a passive tube supplied by a fixed amount of blood; its vessels continuously constrict and dilate in response to neural signals, hormones, local metabolites and the demands created by feeding. In a premature infant, these regulatory systems may not yet be fully coordinated, making the circulation sensitive to relatively small physiological shifts.
The finding also helps explain why the clinical impact of respiratory support cannot be judged from lung function alone. A therapy may improve oxygenation and reduce respiratory effort while simultaneously producing changes in circulation that deserve monitoring. This does not mean that a measured reduction in mesenteric blood flow will inevitably lead to necrotizing enterocolitis, a severe inflammatory and ischemic disorder of the premature intestine. The study, as identified by its title, addresses blood flow rather than establishing that either respiratory strategy causes intestinal disease. Mesenteric perfusion is one component of a much larger process involving infection, feeding, intestinal maturity, systemic blood pressure, oxygen exposure and the infant’s overall condition. Even so, the circulation findings provide a biological signal that may help researchers understand why some infants tolerate feeding and respiratory treatment better than others.
For neonatal teams, the result reinforces the importance of individualized care. The choice between CPAP and high-flow support is generally based on several factors, including the infant’s breathing pattern, oxygen requirement, blood-gas measurements, airway stability, comfort and risk of treatment failure. The new evidence suggests that clinicians should be cautious about assuming that high-flow support is automatically less consequential for the gut, or that CPAP alone explains every change in abdominal or feeding status. Careful observation remains essential, particularly around the introduction and advancement of enteral nutrition. Changes in abdominal distension, residual symptoms, stooling, blood pressure or respiratory condition may all need to be interpreted together rather than attributed to a single device.
The work also opens several questions for future research. Investigators will need to determine how mesenteric blood flow changes over time, whether the magnitude of the effect depends on pressure or flow settings, and how perfusion responds before and after feeding. It will be important to learn whether infants at different gestational ages show different patterns, and whether measurements of intestinal circulation can predict clinically important outcomes. Studies combining blood-flow assessment with oxygen delivery, cardiac output and intestinal oxygenation could provide a more complete picture than any single measurement. Randomized comparisons and larger cohorts may also clarify whether the observed similarity between CPAP and high-flow support persists across different clinical settings. Until those data are available, the study’s most practical contribution is a reminder that non-invasive respiratory support is not physiologically confined to the lungs.
For parents and the wider public, the message is one of refinement rather than alarm. CPAP and high-flow therapy remain important tools for helping premature infants breathe and avoid invasive ventilation. The study does not establish that one treatment is unsafe, nor does it show that every infant receiving either therapy experiences harmful intestinal injury. Instead, it highlights a subtle effect that may be invisible without specialized assessment: the possibility that both approaches can influence blood delivery to the developing gut. By bringing this interaction into focus, Rajay and Toldi’s report may encourage more integrated neonatal monitoring and more precise respiratory care. In the long term, understanding how breathing support, circulation and nutrition interact could help physicians protect not only the premature infant’s lungs, but also the fragile intestinal system that is essential for recovery and growth.
Subject of Research: Mesenteric blood flow in preterm neonates receiving non-invasive respiratory support
Article Title: Mesenteric blood flow is equally compromised in preterm neonates receiving CPAP or high-flow respiratory support
Article References: Rajay, K., Toldi, G. “Mesenteric blood flow is equally compromised in preterm neonates receiving CPAP or high-flow respiratory support.” Pediatric Research (2026). https://doi.org/10.1038/s41390-026-05408-3
Image Credits: AI Generated
DOI: 10.1038/s41390-026-05408-3
Keywords: preterm neonates, mesenteric blood flow, CPAP, high-flow respiratory support, neonatal circulation, intestinal perfusion, premature infants, respiratory care
