The present disclosure pertains to a neonatal feeding tube having a double lumen and permitting the simultaneous functions of feeding and gas venting.
Of the 4 million newborns delivered in the US each year, approximately 400,000 will require some degree of neonatal intensive care. The length of stay in the neonatal intensive care unit (NICU) for these newborns ranges from hours to months, and varies according to the degree of prematurity, extent of other pathologies, associated malformations, and other complicating factors. The current national average NICU length of stay is around 14 days.
One of the most common problems these newborns face is that of respiratory distress.
Newborn respiratory distress may be caused by various factors, singular or in combination; common causes include prematurity, infection, and some type of amniotic fluid aspiration. Respiratory support for these infants range from “non-invasive” means such as an oxygen hood, nasal cannula, high-flow nasal cannula (HFNC), and nasal continuous positive airway pressure (NCPAP), to “invasive” endotracheal mechanical ventilation.
Recent evidence has steered neonatal clinicians to replace invasive respiratory support with as much non-invasive support as clinically feasible. This “kinder, gentler” approach to neonatal respiratory support results in less short-term lung injury and improved long-term pulmonary and neurodevelopmental outcomes. In response to these findings, NCPAP and HFNC have replaced mechanical ventilation as the major modes for the delivery of respiratory support in many NICUs. While pulmonary outcomes have improved, the use of NCPAP/HFNC has come with some potentially troublesome side effects. These include nasal trauma, pneumothorax, and gastrointestinal (GI) distension (due to excessive air swallowing or aerophagia) with its resultant feeding intolerance. While the learning curve has minimized several of these unwanted side-effects, gastrointestinal distension remains a vexing problem for caregivers managing neonates on NCPAP/HFNC.
A second problem many ill newborns face is related to their nutrition. Adequate nutrition is crucial for healing, as well as proper development of the newborn brain. An important collateral complication of neonatal respiratory distress and its causes is the prevention of the baby to take feedings by mouth. Until able to feed orally, these infants are nourished by some combination of intravenous and gastric tube feedings, with the ultimate goal of all oral feedings. Flexible gastric feeding tubes, inserted into the stomach via the nose or mouth, are initially used to provide a simple, safe way to deliver the maximum amount of nutrition until these infants have recovered to take adequate feedings by mouth. Not unexpectedly, many of these ill babies have trouble tolerating even small amounts of enteral feedings due to their degree of illness. Feeding intolerance limits enteral nutrition delivery, which in turn can slow healing, increase infection rates, and subsequently negatively impact hospital course, length of stay, and long-term outcomes.
Achieving the simultaneous goals of providing non-invasive respiratory support, while maximizing nutrition, is often challenging in the neonatal population. These areas of care are in fact intrinsically related and may result in significant, deleterious interference with one another. Specifically, respiratory support may negatively impact feeding tolerance/delivery due to its resultant patient agitation, GI distension, and hormonal alterations. These complications are compounded by the fact that nearly all sick newborns (especially those that are premature) have various degrees of inherent gastro-intestinal dysfunction. Alternatively, the delivery of adequate enteral nutrition, while necessary for growth and development, may impact negatively on various aspects of respiratory support.
To illustrate these challenges, consider the previously noted gastrointestinal distension seen commonly with NCPAP/HFNC. The accumulation of CPAP-derived gas in the GI tract is so common it has been come to be known as “CPAP-belly.” While intubated, neonates theoretically have gas delivered mainly to the lungs. On the other hand, NCPAP/HFNC deliver continuous gas flow through the nasopharynx; this gas can enter both the lungs and the GI tract. While this flow assists gas exchange in the lungs, the undesired delivery and accumulation of gas in the GI tract may result in significant GI distension. Unchecked, progressive accumulation of air in the gut may result in more respiratory distress (by pushing up on the diaphragm), which in turn may result in escalation of respiratory support, and often ultimately affect the success of the delivery of adequate enteral nutrition.
Current standard management of babies on NCPAP includes the use of a single lumen gastric feeding tube which functions as both a route for enteral nutrition, as well as a route to allow venting of excessive gastrointestinal gas. When feedings are not running through the gastric tube, it can be opened (“vented”) to help allow egress of gastric air and thus (hopefully) limit the accumulation of unwanted, excessive gastrointestinal gas. This technique becomes a problem when the gastric tube vent time does not keep up with gastric gas accumulation, resulting in CPAP belly. In addition, gastric contents may block the lower holes in the feeding tube, preventing the effective venting of gas. Further complicating matters, smaller sicker babies may require feedings slowly delivered over time, thus lessening the time period that the gastric tube is available to function as a vent, and increasing the time for gas accumulation. Simply put, the limitation of a single lumen gastric tube is its inability to perform both enteral feeding and gastric venting simultaneously. This can become a serious shortcoming when caring for a baby on NCPAP/HFNC.
In some infants, unrelenting abdominal distension on NCPAP/HFNC leads caregivers to try the use of 2 separate gastric tubes—one to provide nutrition and one to vent the stomach. While this technique is effective in some cases, it is fraught with issues of maintaining the proper position, alignment, and function of both tubes. In some infants, unchecked CPAP belly/distension may lead to endotracheal intubation in a final attempt to limit aerophagia and improve feeding tolerance/nutrition.
Existing single lumen nasogastric feeding tubes have an opening at the lowermost tip, and usually 1-2 other openings very near the lowermost tip. This lumen either carries feedings down into the stomach, or when feedings are off, gas up and out of the stomach. This either/or proposition is problematic when required feeding time impinges on gas vent time; this mismatch in venting time may result in excessive gastrointestinal gas accumulation and its related problems.
An additional group of nasogastric tubes function purely to provide nasogastric venting. This type of tube is used in instances when gastro-intestinal peristalsis is impaired (ileus), as seen in surgical patients. Known as a “replogle” type tube, it is stiffer and has thicker walls (to prevent collapse) than the typical feeding tube. This is due to the need for the application of active suction (i.e. negative pressure that would collapse the wall of a thinner, non-reinforced tube). These tubes may also have a second “flush” lumen that connects to the upper part of the suction lumen, to allow flushing of debris from the suction lumen to prevent obstruction with gastrointestinal debris. By design, this replogle tube is stiffer than a routine feeding tube so that it performs with an active negative pressure application. While a necessary neonatal tool, the replogle tube comes with well-known, inherent risks due to its composition. Stiffer, less modern plastics result in a much higher risk of gastric perforation in this fragile population. In addition, it is not formatted to deliver nutrition but rather only the removal of gastrointestinal contents. These factors also contribute to each individual tube's short lifetime of use (hours to days) in each patient.
The present disclosure relates to an improved neonatal gastric feeding tube. The improved neonatal feeding tube is a double lumen tube with separate lumens to provide separate routes for the simultaneous actions of gastric feeding and gas venting. This unique, specialized gastric tube can deliver up to continuous enteral nutrition via a feeding lumen, while simultaneously allowing for continuous gastric venting via side holes of a second venting lumen.
The functional goals of the double lumen feeding tube are intricately related and synergistic. The beneficial combination of minimizing the gastrointestinal and pulmonary side effects of excessive gastrointestinal gas, paired with improved delivery of enteral nutrition, is expected to improve overall patient care management and health, and thus theoretically speed the patient's overall recovery. Research is clear that maximizing enteral nutrition is important in the promotion of healing and growth potential for these infants, as well as improving long-term growth and development.
It is clear that the gastric feeding tube is an indispensable tool for improving the long-term outcome in intensive care neonates. The delivery of enteral nutrition, while simultaneously venting the stomach, by a single gastric tube, is unique to modern NICU care. The dual, simultaneous capabilities of feeding and venting represent a significant upgrade to the current single lumen system. The anticipated improvements in short-term outcomes and length of hospital length of stay, coupled with improved long-term outcomes, are the ultimate dyad of continually sought goals of all dedicated providers of modern neonatal intensive care.
The present disclosure relates to a double lumen neonatal feeding tube having a dedicated feeding lumen coupled to a dedicated venting lumen, together forming a single tube. In preferred embodiment, the double lumen feeding tube is made of modern soft plastic and has a tube diameter that is not significantly larger than current single lumen feeding tubes. The feeding lumen has a hole at the tip and at least one additional hole on the side of the feeding lumen in close proximity to the tip. The venting lumen terminates at a position inside the tube that does not reach the tip of the feeding lumen and has at least three staggered side holes relatively close to its termination point. The holes in the venting lumen extend higher on the tube than the holes in the feeding lumen in order to avoid interfering with feedings and provide additional ports for venting.
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In preferred embodiments, the double lumen feeding tube has an overall size of about 8 to 9 Fr, or a circumference of about 8.3 mm to about 9.4 mm. Within the double lumen feeding tube, in certain embodiments, the feeding lumen may have a size of about 4 to 6 Fr, or a circumference of about 4.2 to about 6.3 mm. In additional preferred embodiments, the feeding lumen has a size of about 5 Fr, or a circumference of about 5.2 mm. In certain embodiments, the venting lumen has a size of about 5 to 7 Fr, or a circumference of about 5.2 to about 7.3 mm. In additional preferred embodiments, the venting lumen has a size of about 6 Fr, or a circumference of about 6.3 mm. Because the feeding lumen and the venting lumen share a central wall, their combined circumference is less than their individual circumferences added together.
The double lumen feeding tube is preferably constructed of a soft, flexible plastic such as polymeric silicone (such as SILASTIC®, Dow Corning, Midland, Mich.), polyurethane, silicone rubber, nylon, polyethylene terephthalate, latex, or combinations thereof. For ease of assembly, it is preferred that the double lumen feeding tube be constructed of a single type of material. However, certain embodiments may include the use of a stiffer, less flexible plastic for the venting lumen portion of the double lumen feeding tube. This will accommodate the potential use of negative pressure, similar to a replogle tube, on the venting side of the double lumen tube.
In certain additional embodiments, the double lumen feeding tube is printed with markings, including but not limited to measurement lines for placing the tube at a correct depth in a patient and/or suitable symbols, letters or labels to identify which lumen is for feeding and which lumen is for venting. In certain additional embodiments, the double lumen feeding tube further comprises one or more radi-opaque markings or lines which will be visible on a radiograph (X-ray).