Enteral feeding is essential for critically ill, head trauma, and burn patients who are unable to swallow.
To evaluate a new nasoenteral feeding tube with distal tip balloon designed to facilitate post-pyloric migration and avoid misplacement in the trachea.
A case series was conducted in 50 critically ill patients aged 19 to 89 years receiving mechanical ventilation and requiring enteral nutrition in a teaching hospital. Patients received a soft, flexible, kink-resistant nasoenteral feeding tube with a balloon near the distal tip to enhance postpyloric migration by peristalsis. The feeding tube was inserted with a novel thread technique to reduce posterior nasopharyngeal trauma and tube misplacement. Pulse oximetry provided early detection of misplacement into the trachea. Placement was verified by abdominal radiography performed shortly after the procedure and repeated within 24 hours if needed.
Postpyloric placement was achieved at 30 minutes in 24% of patients and by the following morning in 70% of patients. Tracheal intubation occurred in 1 patient but was recognized and corrected without injury. No tube occlusion from kinking occurred.
Early gastric or postpyloric feeding can be provided with this novel feeding tube. Its use facilitates quick bedside recognition of accidental misplacement in the trachea, reducing the chance of pneumothorax. The tip balloon reduces deeper placement into a lung and promotes distal migration into the small intestine. The design prevents occlusion from kinking, which is common with conventional feeding tubes. Nurses easily adopted the tube and insertion technique.
Enteral feeding has long been the preferred method of nutritional support for critically ill patients. It reduces villous atrophy and bacterial translocation from the gut lumen into the bloodstream.1–4 Delivering feeding in a timely manner is important because failure to provide adequate early nutrition correlates with longer intensive care unit (ICU) stays, additional days receiving mechanical ventilation, and increased frequency of infectious complications.5–8
Although placing a feeding tube through the nares is routine, complications can occur. Feeding tubes can traumatize the nasopharyngeal mucosa during insertion, especially in patients who cannot flex the neck because of trauma, osteoarthritis, or recent cervical spine surgery. Feeding tubes can also be misplaced into the trachea. McWey et al9 found that of 1100 nasoenteric intubations, 1.3% involved a tube misplacement. Thirteen of the 14 patients with misplaced feeding tubes experienced pulmonary complications including pneumonia, pneumothorax, and hydrothorax.9,10 Other studies have found a higher incidence of misplacement into the trachea, with misplacement rates ranging from 2% to 4%.11,12
An additional challenge in enteral feeding tube placement is difficulty in achieving postpyloric placement. Some trial results suggest that although the risk of pneumonia is lower with transpyloric placement, striving for postpyloric placement delays initiation of feeding without any benefit in total caloric intake.13–15 However, Hsu et al16 showed that postpyloric feeding led to higher protein and calorie intake and fewer complications, compared with gastric feeding. A 2015 meta-analysis published in the Cochrane Database of Systematic Reviews stated that “a post-pyloric feeding tube should be used routinely for all ICU patients, when this approach is feasible.”5
The thread-steering technique reduced patient discomfort and nasopharyngeal trauma.
The American Society for Parenteral and Enteral Nutrition 2017 guideline recommends enteral nutrition (within 24-48 hours) for nearly all critically ill patients and suggests that initiating enteral feeding in the stomach is acceptable.15 The European Society for Clinical Nutrition and Metabolism 2019 guideline recommends using gastric access as the standard and implementing postpyloric access only when a patient has intolerance to gastric feeding because of gastroparesis.14
Another consideration is that long feeding tubes designed to reach the duodenum or jejunum frequently coil and kink in the stomach, causing occlusion. This occlusion requires partial withdrawal of the tube, which reduces the tube length in the stomach and the likelihood of postpyloric migration. Nasogastric suction tubes designed for aspiration of gastric contents are thicker and more rigid than feeding tubes to prevent collapse during suction; they are not designed or intended for postpyloric feeding.
The most important barrier to postpyloric feeding is difficulty in proper placement. The feeding tube evaluated in this study (Gabriel Feeding Tube, Syncro Medical Innovations, Inc) addresses this issue by incorporating a balloon at the distal tip of the feeding tube (Figure 1). The balloon has 2 functions. First, the balloon can be inflated when the device is inserted to a depth of approximately 30 cm to confirm esophageal rather than tracheal positioning. When the balloon is inflated at this depth, pulse oximetry is performed to assess positioning. If the tube is improperly placed in the trachea, the patient’s oxygen saturation will drop, and the balloon should be deflated immediately and tube withdrawn to the 18-cm mark before reinsertion. If misplacement in the airway occurs but is missed, the tube with inflated balloon cannot be advanced into smaller bronchioles and cause pneumothorax. Second, the balloon at the distal tip of the device is propelled by peristalsis to a postpyloric position in the distal duodenum or proximal jejunum.
For patients with a retropharyngeal hematoma after anterior cervical fusion or those who cannot flex the neck, feeding tube placement can cause retropharyngeal damage. In the feeding tube evaluated in this study, a surgical silk thread can be looped through distal holes in the tube and used to deflect the tube downward to the oropharynx by pulling on the 2 ends of the thread at the 6-o’clock position. The thread is then discarded. This atraumatic technique initially proved useful for patients in whom conventional feeding tube insertion had failed and was later generalized to all patients. The objective of this study was to evaluate the efficacy of the nasoenteral feeding tube with balloon device designed to facilitate safe postpyloric migration and avoid accidental tracheal placement.
The US Department of Defense funded development of the device. After premarket notification clearance was received from the US Food and Drug Administration, approval was obtained from the local institutional review board and the Department of Defense Human Research Protection Office. The first author designed and developed the tube.
This prospective case series consisted of 50 patients at a teaching, community, level I trauma hospital. Conventional feeding tube placement had failed in many of these patients. Eligible patients were those older than 18 years whose routine nursing care included an order for a nasoenteral feeding tube. Written informed consent was obtained from all patients or their legal representatives. Each participating nurse was required to observe 1 insertion of the feeding tube with balloon before performing the procedure. Patient discomfort as indicated by lacrimation, bleeding, or thrashing during the procedure was recorded.
Exclusion criteria included midfacial fracture; recent surgical procedure involving the larynx, pharynx, esophagus, or stomach; hemodynamic instability; suspected upper gastrointestinal bleeding or stenosis; unstable cervical, thoracic, or lumbar spine fractures; pregnancy; and age younger than 18 years. Any medical device that contains metal can generate heat and artifacts inside magnetic resonance (MR) equipment and must be tested to determine safety. After the study was completed, MR safety testing was conducted. The results indicated that the tube was safe if used in a 1.5-T or 3.0-T MR imaging machine (MR-conditional approval). This fact was not known before the study, so patients who were expected to need MR imaging were excluded.
The feeding tube used in this study is a 12F tube that is 130 cm long and has a 3-mL balloon at its distal end. Another 3-mL pilot balloon at the proximal end indicates whether the distal balloon is inflated. The wall of the tube is lined with a spiral wire that prevents occlusion from kinking and allows the tube wall to be thin, increasing its flexibility. A braided 7-strand stainless steel stiffening central stylet prevents coiling in the mouth during insertion and provides column strength to facilitate placement into the stomach. This feeding tube is more flexible than traditional feeding tubes, and the removable stylet is stiffer than traditional stylets.
After the patient’s nares were numbed with benzocaine gel, lubricant jelly was applied to the distal end of the tube and to the nostril. A silk thread was placed through the holes in the distal end of the tube. While holding both ends of the thread, the operator inserted the tube until resistance was felt at the nasopharynx (Figure 2). Both ends of the thread were then pulled to deflect the tube tip down toward the oropharynx. The thread was removed by pulling on 1 end. When the tube was inserted to the 18-cm mark, the patient (if awake) was asked to swallow while the tube was advanced to the 30-cm mark. At this point, the tube was expected to be in the middle of the esophagus. The proximal pilot balloon and the balloon at the distal tip were then inflated with 6 mL of air while oxygen saturation was monitored by pulse oximetry (Figure 3). If oxygen saturation dropped by greater than 5 percentage points upon balloon inflation, the balloon was deflated and the tube was withdrawn to the 18-cm mark and then reinserted. If oxygen saturation did not drop, the tube was advanced to the 70-cm mark with the balloon inflated (Figure 4). The stylet was withdrawn as the tube was advanced to the 100-cm mark (Figure 5). After the tube was secured to the nose, 60 mL of warm water was instilled to stimulate peristalsis (Figure 6). A kidney, ureter, and bladder radiograph was then obtained to confirm placement before initiation of feeding. If radiography indicated that the tube had already advanced beyond the pyloric sphincter (Figure 7), no further radiographs were ordered. If the initial radiograph showed the tube tip in the stomach, a follow-up radiograph was obtained within 12 to 24 hours to monitor tube migration into the duodenum or jejunum (Figure 8). The balloon at the distal tube end was deflated when the tube reached the jejunum or before removal. Patients were fed with the head of bed elevated 30 ° once gastric or postpyloric placement was confirmed.
Fifty patients underwent placement of the feeding tube with balloon. Most tubes were inserted by ICU nurses. Of the 50 patients, 44 (88%) were in critical care units and 13 (26%) were receiving mechanical ventilation at the time of insertion. Six of the patients had recently been transferred from a critical care setting. The participants’ ages ranged from 19 to 89 years (median, 65 years). The group of patients included 27 women and 23 men, with weights ranging from 38 to 150 kg (median, 75 kg; 9 patients weighed over 100 kg). Primary critical illnesses were intracranial hemorrhage (11 patients), stroke (10), respiratory failure (5), major trauma (4), delirium or encephalopathy (4), brain tumor (3), gunshot wound (3), acute pancreatitis (2), septic shock (2), and others (6).
All 50 patients received initial radiography, which documented placement of the tube tip in the stomach in 38 patients (76%), the duodenum in 8 (16%), and the jejunum in 4 (8%). The 38 patients with the feeding tube tip in the stomach underwent repeat radiography 12 hours later. At this time, the tube tip was postpyloric in 23 patients, with 16 tubes positioned in the duodenum and 7 in the jejunum. Among the 50 patients, the final tube tip position was in the stomach in 15 patients (30%) and distal to the pylorus in 35 patients (70%), with 24 in the duodenum and 11 in the jejunum.
The balloon provides early recognition of lung misplacement and prevents pneumothorax.
No instances of pneumothorax occurred. During 1 insertion, oxygen saturation measured by pulse oximetry dropped to 84% when the balloon was inflated at the 30-cm mark, suggesting tracheal insertion. The balloon was deflated and the tube was pulled back to the 18-cm mark and reinserted into the stomach. The mean procedure time was 7.3 minutes (range, 2-20 minutes). In most patients enrolled in this study, nasopharyngeal intubation using conventional feeding tubes without the steering thread technique had failed.
This case series achieved a postpyloric placement rate of 70%, with no instances of undetected tracheal misplacement. Of the 38 initial tube placements into the stomach, 23 tubes (61%) migrated distally by peristalsis, as shown on follow-up radiography. It is possible that with additional time, higher rates of postpyloric migration could be achieved. Most follow-up imaging was obtained the next morning, 12 to 24 hours after tube placement. The tube’s physical properties and distal end balloon may have enhanced postpyloric migration by peristalsis. The tube is made of thin-walled, flexible polyvinylchloride that does not kink and occlude in sharp turns or loops because of the thin spiral wire lining the tube wall. The relatively stiff stylet improved the ability to advance the tube against resistance without the tube buckling. The wire-reinforced tube wall allowed for insertion of an adequate tube length, looped or coiled in the stomach without occlusion from kinking (Figure 9), allowing ample tube length for distal migration by the effect of peristalsis on the tube’s distal end balloon.
Previous studies have found success rates ranging between 43% and 97% for electromagnetic-guided placement (EMP) of postpyloric feeding tubes.17 However, pneumothorax is a concern with the EMP device and similar small-bore feeding tubes with stylets. The wide range of postpyloric placement rates for EMP has largely been attributed to operator experience. One study showed a postpyloric placement rate of 60% for an operator’s first 25 EMPs and 84% for the next 25 EMPs.18 Waiting for postpyloric placement often delays enteral feeding. For example, a feeding tube placement ordered on Friday might be inserted on Monday, when a trained nurse is available to insert the EMP device. A meta-analysis found a mean delay of 16 hours in patients who were randomized to receive postpyloric feeding rather than gastric feeding (P < .001).19 Using the feeding tube with balloon for delivery of early gastric feeding with a high potential for postpyloric migration may address this issue of delay in nutrition delivery while also reducing the risk for aspiration pneumonia. Patients with good peristalsis and good gastric emptying, who can typically tolerate gastric feeding, are at an even lower risk for aspiration when fed distally. They may benefit from a previously placed, distally located feeding tube if they develop ileus or weaker peristalsis because of surgical procedures or other complications.
Our study showed good rates of postpyloric feeding tube placement by nurses, in addition to reduced cost and no delay of feeding. In a multicenter trial, the mean cost of EMP was $522, excluding placement confirmation radiography.17 The placement cost associated with the feeding tube with balloon is $95 plus the cost of confirmation radiography. In this case series, 1 patient experienced a drop in oxygen saturation after balloon inflation. This finding allowed for prompt repositioning of the tube into the esophagus, avoiding a pneumothorax. The rates of tracheal misplacement of enteral tubes range between 1.3% to 4% in published studies, similar to the rate of 2% (1 of 50 patients) in our study. However, up to 50% of tracheal misplacements with other enteral feeding tubes may lead to pneumothorax. This complication is likely less common with the feeding tube with balloon, but validation of this hypothesis would require a properly powered study.
In this small study, no cases of pneumothorax occurred because deep tracheal placement was avoided. Even if inadvertent tracheal insertion occurs with this tube, it is unlikely that the tube with the inflated 13-mm–diameter balloon could be advanced into small bronchioles and perforate the pleura. A brief drop in oxygen saturation can be recognized and corrected promptly by deflating the balloon, an advantage over treating a pneumothorax. Thus, this tube design and technique may lead to less serious lung injury than the EMP device.
Enteral feeding using the feeding tube with balloon can be started early and has a 70% chance of postpyloric migration within 24 hours, allowing prompt initiation of nutrition and reduced aspiration risk in critically ill patients. In this case series, pulse oximetry after balloon inflation revealed tracheal tube placement in 1 patient, allowing for prompt tube repositioning and avoidance of pneumothorax.
In this study we used a new nasopharyngeal placement technique incorporating a silk thread at the distal end of the device to provide downward deflection of the distal end into the oropharynx. This technique subjectively reduced patient discomfort, as observed by a lack of patient lacrimation, bleeding, or thrashing, and was also useful in patients who were unable to undergo neck flexion for tube placement. The insertion technique was easily learned and adopted by nurses with basic skills in inserting nasogastric tubes.
This research study was conducted at Medical Center Navicent Health, Macon, Georgia. We thank Michael Dixon, RN, Sky Buckhammer, RN, Brittany Smith, RN, Joshua White, RN, and Sabrina Camp, RN, for placing feeding tubes for patients in the intensive care unit and Catherine Rimando, RN, and Christine Fite, RN, for placing feeding tubes for patients on the general medical and surgical floors. Sabry Gabriel and Samy Gabriel contributed to the conception and design of the research; Caleb Ackermann contributed to data acquisition; Richard Ackermann and Sabry Gabriel contributed equally to data analysis and interpretation; and Sabry Gabriel, Richard Ackermann, and Samy Gabriel drafted the manuscript. Leslie Swadener-Culpepper educated nurses regarding insertion procedure, screened patients for eligibility, and collected data and consent forms. All authors critically revised the manuscript, agree to be fully accountable for ensuring the integrity and accuracy of the work, and read and approved the final manuscript.
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This research study and device development were funded by the US Department of Defense (award W81XWH-09-2-0097 to Syncro Medical Innovations, Inc, Macon, Georgia). Dr Sabry Gabriel is the founder and a shareholder of Syn-cro Medical Innovations, Inc. This company received funding to develop the feeding tube’s tracheal avoidance feature and other features that facilitate enteral access and a high incidence of postpyloric migration. Dr Sabry Gabriel received US patent 9 713 578, Japanese patent 6357311, Chinese patent ZL201310710594.0, and European patent 2745828. The Food and Drug Administration provided premarket notification clearance (K160787).
To learn more about enteral feeding, read “Association Between Enteral Feeding, Weight Status, and Mortality in a Medical Intensive Care Unit” by Vest et al in the American Journal of Critical Care, March 2018;27: 136-143. Available at www.ajcconline.org.