Comparison of Syringe Compression Force Between ENFit and Legacy Feeding Tubes

Background: Since initial report in 1972, misconnections continue to be an issue, especially in hospitalized patients with multiple access devices. A new small‐bore connector standard (ENFit) has been proposed in order to minimize misconnections. Methods: Commercially available finalized ENFit tubes of a variety of sizes (14 French [Fr] size, 18Fr, 20Fr, 24Fr, and low‐profile) were obtained for current testing. Variety of commercially available formulas including blenderized tube feeding (BTF) products (Jevity 1 Cal, Abbott Nutrition, Abbott Park, IL; Nourish, Functional Formularies, Centerville, OH; Real Food Blends, Chesterton, IN) were tested. Results: Data from individual measurements were aggregated for ENFit and legacy tubes and revealed higher syringe compression force in legacy tubes compared with ENFit tubes for 20Fr size with Jevity formula. Our institution's BTF formula revealed that legacy tubes had lower syringe compression force than ENFit tubes for 14Fr tube size. Remaining measurements revealed no significant difference. Model 1 of regression analysis revealed that only formula and tube size were significant with R² of 0.63. Model 2 evaluating the impact of tube size, blender, time of blending, and legacy vs ENFit revealed that tube size, blender used, and blending time were significant with legacy vs ENFit being nonsignificant (R² of 0.72). Conclusions: Overall, only a small number of tube sizes (14Fr and 20Fr) with selected formulas revealed a significant difference between ENFit and Legacy tubes, with remaining studies finding no significant difference. Regression analysis revealed that variables such as formula, size of tube, blender used, and time of blending may have more impact on compression force.     

Dual‐Purpose Gastric Decompression and Enteral Feeding Tubes Rationale and Design of Novel Nasogastric and Nasogastrojejunal Tubes

Background: The importance of early postoperative nutrition in surgical patients and early institution of enteral nutrition in intensive care unit (ICU) patients have recently been highlighted. Unfortunately, institution of enteral feeding in both groups of patients often has to be postponed due to delayed gastric emptying and the need for gastric decompression. The design of current polyvinylchloride (PVC) gastric decompression tubes (Salem Sump [Covidien, Mansfield, MA] in the United States; Ryles [Penine Health Care Ltd, Derby, UK] in the United Kingdom and Europe) make them unsuitable for their subsequent use as either nasogastric enteral feeding tubes or for continued gastric decompression during postpyloric enteral feeding. To overcome these problems, we have designed a range of polyurethane (PU) dual‐purpose gastric decompression and enteral feeding tubes that include 2 nasogastric tubes (double lumen to replace Salem Sump; single lumen to replace Ryles). Two novel multilumen nasogastrojejunal tubes (triple lumen for the United States; double lumen for the United Kingdom and Europe) complete the range. By using PU, a given internal diameter (ID) and flow area can be incorporated into a lower outside diameter (OD) compared with that achieved with PVC. The ID and lumen and flow area of an 18Fr (OD 6.7 mm) PVC Salem Sump can be incorporated into a 14Fr (OD 4.7 mm) PU tube. The design of aspiration/infusion ports of current PVC and PU tubes invites occlusion by gastrointestinal mucosa and clogging by mucus and enteral feed. To overcome this, we have designed long, single, widened, smooth, and curved edge ports with no “dead space” to trap mucus or curdled diet. Involving up to 214° of the circumference, these ports have up to 11 times the flow areas of the aspiration ports of current PVC tubes. Conclusion: The proposed designs will lead to the development of dual‐purpose nasogastric and nasojejunal tubes that will significantly improve the clinical and nutrition care of postoperative and ICU patients.     

Establishing Early Enteral Nutrition With the Use of Self‐Advancing Postpyloric Feeding Tube in Critically Ill Children

Introduction: Early nutrition support is an integral part of the care of critically ill children. Early enteral nutrition (EN) improves nitrogen balance and prevents bacterial translocation and gut mucosal atrophy. Adequate EN is often not achieved as gastric feeds are not tolerated and placing postpyloric feeding tubes can be difficult. Spontaneous transpyloric passage of standard feeding tubes without endoscopic intervention or use of anesthesia can range from 30%?80%. The authors report on their experience with a 14Fr polyurethane self‐advancing jejunal feeding tube in a pediatric population. These tubes have been used in the adult population with success, but to the authors’ knowledge, there have been no reports of its use in the pediatric age group. Case Series: The authors present 7 critically ill patients 8–19 years old, admitted to the pediatric intensive care unit, in whom prolonged recovery, inability to tolerate gastric feeds, and dependence on ventilator were predicted at the outset. The jejunal feeding tube was successfully placed on first attempt at the bedside in all 7 patients within the first 24 hours without the use of a promotility agent or endoscopic intervention. Nutrition goal achieved within 48 hours of feeding tube placement was reported for each patient. This case series demonstrates that children fed via the small bowel reached their nutrition goal earlier and did not require parenteral nutrition. Conclusion: The self‐advancing jejunal feeding tube can be used effectively to establish early EN in critically ill children.     

Fluoroscopy‐Guided Percutaneous Gastrostomy With Pull Technique for the Amyotrophic Lateral Sclerosis Patients With Very Low Vital Capacity

Background: The purpose of this study was to evaluate the safety and usefulness of fluoroscopy‐guided percutaneous gastrostomy (FPG) in patients with amyotrophic lateral sclerosis (ALS) using a large‐profile gastrostomy tube accompanied by the pull technique. This procedure was done without an accompanying endoscopy or gastropexy. Methods: Thirty‐six patients with ALS underwent FPG using a large‐profile gastrostomy tube accompanied by the pull technique. A 24 Fr pull‐type tube was inserted under fluoroscopic guidance into the mouth and pulled to the upper‐abdominal puncture site using a snare. The technical success rate, occurrence of complications, and clinical outcomes were evaluated. Results: The technical success rate was 100%. There were no procedure‐related mortalities or respiratory complications. The mean forced vital capacity of the patients was 732 mL (17.7% of the normal predicted value). During the procedure, 16 patients required ventilator support by nasal mask or tracheostomy. The tube indwelling period ranged from 1 to 24 months (average, 9.3). During this period, all the tubes were maintained in a proper position. In 18 patients, the tube was exchanged after 6 months without any problems. Conclusions: The FPG procedure using a 24 Fr tube and the pull technique shows a high rate of technical success. This procedure has a low risk for respiratory complications because endoscopic guidance is not needed. In addition, gastropexy is not required, which allows a large‐profile catheter to be inserted during a single procedure.     

Comparison of Gravity Flow Rates Between ENFit and Legacy Feeding Tubes

Background: Misconnections between enteral supplies and other access devices have led to significant morbidity and mortality. To reduce misconnections, a standard small‐bore connector has been developed (International Organization for Standards 80369‐8; ENFit). The full impact of transition to this connector is not known, however. Method: Working with major manufacturers and Food and Drug Administration, we obtained ENFit and comparative legacy tubes of variable sizes (low‐profile, 14F, 18F, 20F, and 24F balloon gastrostomies). Gravity enteral feeding was simulated with an empty bolus syringe attached to the feeding tube to be tested. The tube was clamped and filled to the 60‐mL mark with liquid (water, Jevity 1 Cal, Isosource HN, Isosource 1.5 Cal, Two Cal HN, and Nourish). The clamp was released, and time for formula to leave the syringe was recorded. Results: There was no difference in flow rate between the aggregate legacy and ENFit tubes for the low‐profile, 18F, and 20F sizes. The ENFit 14F tubes had a lower flow rate vs the legacy tubes, largely due to the low flow rates seen with the 1 ENFit tube. Similarly, 24F ENFit tubes with some formulas yielded lower flow rates as opposed to legacy. Conclusion: Overall, for the low‐profile, 18F, and 20F sizes, the ENFit tubes had similar flow rates when compared with the legacy tubes. For the 14F and 24F sizes, the flow rate of ENFit tubes was significantly lower, which could result in longer EN delivery for patients who are using these tubes to provide gravity feeding.     

The evolving role of post-ligament of Trietz nasojejunal feeding in enteral nutrition and the need for improved feeding tube design and placement methods

Nutrition support is an important link in the chain of therapy for intensive care unit patients. The early institution of nutrition support significantly reduces the incidence of septic complications, reduces mortality, and shortens hospital stay. Unfortunately, impaired gastrointestinal function, particularly gastric atony, restricts the use of nasogastric enteral tube feeding, and the use of this route of administration in these patients can lead to regurgitation, aspiration, and the development of pneumonia. Postpyloric enteral feeding was heralded as a means of overcoming many of these problems. Overall, the results of controlled studies do not support a role of postpyloric duodenal feeding in reducing the incidence of aspiration pneumonia. As a consequence, post-ligament of Treitz nasojejunal enteral feeding is proposed as the technique of choice in these patients. Feeding tube design must incorporate a gastric aspiration port to overcome problems of gastroesophageal acid reflux, duodenogastric bile reflux, and increased gastric acid secretion, problems that occur during "downstream" jejunal feeding. Tube placement technique will need to be refined and patients will need to receive a predigested enteral diet. In postoperative surgical patients in the intensive care unit, there is also a need for a newly designed dual-purpose nasogastric tube capable initially of providing a means of undertaking gastric aspiration and decompression and subsequently a means of initiating nasogastric enteral feeding.     

Use of residual volume as a marker for enteral feeding intolerance: prospective blinded comparison with physical examination and radiographic findings.

High gastric residual volumes (RVs) are a frequent cause for cessation of total enteral nutrition (TEN). This study was designed to determine the RV that indicates intolerance or inadequate gastric emptying and to compare the RV findings in a blinded fashion with those findings obtained on physical examination and radiography. Twenty healthy normal volunteers (HNV), 8 stable patients with gastrostomy tubes (GTP), and 10 critically ill patients (CIP) were evaluated prospectively for 8 hours while receiving TEN. No subjects were clearly intolerant (ie, vomiting, aspiration). Of the total RVs recorded, 13.1% were greater than or equal to 150 mL in the CIP group, whereas only 2.4% of the RVs were greater than or equal to 150 mL in the HNV group. None of the RVs in the GTP group were greater than or equal to 150 mL. Objective scores on physical examination failed to correlate with RV (p = .397), as did objective scores on radiography (p = .742). However, objective scores on physical examination were significantly related to scores on radiography (p = .016). Abnormal physical examination findings were found in 4 out of 11 patients (GTP + CIP) with RVs less than 100 mL and in 6 out of 7 with RVs greater than or equal to 100 mL. Abnormal radiographic results were found in 6 out of 11 patients with RVs less than 100 mL, in 7 out of 7 patients with RVs greater than or equal to 100 mL, and in 4 out of 20 HNVs. There was no difference in RVs obtained from the supine or right lateral decubitus positions.(ABSTRACT TRUNCATED AT 250 WORDS)     

Frequency of Aspirating Gastric Tubes for Patients Receiving Enteral Nutrition in the ICU

Background: Enteral nutrition (EN) tolerance is often monitored by aspirating stomach contents by syringe at prescribed intervals. No studies have been conducted to assess the most appropriate time interval for aspirating gastric tubes. We compared gastric tube aspirations every 4 hours (usual care) with a variable regimen (up to every 8 hours aspirations). Methods: This randomized controlled trial (RCT) enrolled patients who stayed in the intensive care unit (ICU) for >48 hours, had a gastric tube, and were likely to receive EN for 3 or more days. Patients were randomized (computer‐generated randomization) to either the control (every 4 hours) or intervention group (variable regimen). The primary outcome was number of gastric tube aspirations per day from randomization until EN was ceased or up to 2 weeks postrandomization. Results: Following Institutional Ethics Committee approval, 357 patients were recruited (control group, n = 179; intervention group, n = 178). No differences were found in age, sex, worst APACHE II score, or time to start of EN. In the intention‐to‐treat analysis, the intervention group had fewer tube aspirations per day (3.4 versus 5.4 in the control group, P < .001). Vomiting/regurgitation was increased in the intervention group (2.1% versus 3.6%, P = .02). There were no other differences in complications. Conclusion: This is the first RCT to examine the frequency of gastric tube aspirations. The frequency of gastric tube aspirations was reduced in the variable‐regimen group with no increase in risk to the patient. Reducing the frequency of aspirations saves nursing time, decreases risk of contamination of feeding circuit, and minimizes risk of body fluid exposure.     

Warfarin Bioavailability With Feeding Tubes and Enteral Formula

Background: Earlier literature showed reduced efficacy of warfarin when co‐administered with enteral nutrition formulas through feeding tubes. This study used an in vitro model for gastric administration of warfarin through a feeding tube to evaluate potential causes for reduced warfarin absorption when administered through feeding tubes. Methods: There were 2 phases of the study. The first phase used an artificial stomach model with or without the infusion of enteral nutrition formula. Warfarin was added to the contents either directly into the vessel or passed through a feeding tube. Warfarin tablet dissolution was compared to the injectable formulation, which served as a control. The second phase used chopped feeding tube material added to beakers containing warfarin in increasing amounts. Results: Warfarin injection and tablet formulations showed decreased solubility when combined with acid. The warfarin solubility was higher when enteral formula was added. Warfarin concentration dropped by 35% when the drug was passed through a feeding tube, as opposed to added directly to the flask. In the second study, the warfarin levels were lower in the beakers containing feeding tubes. Doubling the amount of warfarin added did not raise levels to that of the initial dissolved. Doubling the amount of feeding tube material further reduced the concentration dissolved. Conclusions: Feeding‐tube administration compromises the total amount of warfarin reaching patients. It appears, from this in vitro study, that the mechanism of the interaction of warfarin may be a result of direct binding to the feeding tube.     

Relationship between feeding tube site and respiratory outcomes

Background: It is unclear if placing feeding tubes postpylorically to prevent respiratory complications is worth the extra effort. This study sought to determine the extent to which aspiration and pneumonia are associated with feeding site (controlling for the effects of severity of illness, degree of head‐of‐bed elevation, level of sedation, and use of gastric suction). Methods: A retrospective analysis was performed on a large data set gathered prospectively to evaluate aspiration in critically ill, mechanically ventilated patients. Feeding site was designated by attending physicians and confirmed by radiography. Each patient participated in the study for 3 consecutive days, with pneumonia assessed by the simplified Clinical Pulmonary Infection Score on the fourth day. Tracheal secretions were assayed for pepsin in a research laboratory; the presence of pepsin served as a proxy for aspiration. A total of 428 patients were included in the regression analyses performed to address the research objectives. Results: As compared with the stomach, the percentage of aspiration was 11.6% lower when feeding tubes were in the first portion of the duodenum, 13.2% lower when in the second/third portions of the duodenum, and 18.0% lower when in the fourth portion of the duodenum and beyond (all significant at P < .001). Pneumonia occurred less often when feedings were introduced at or beyond the second portion of the duodenum (P = .020). Conclusions: The findings support feeding critically ill patients with numerous risk factors for aspiration in the mid‐duodenum and beyond to reduce the risk of aspiration and associated pneumonia.     

Comparative Analysis of the Efficacy and Complications of Nasojejunal and Jejunostomy on Patients Undergoing Pancreaticoduodenectomy

Background: The efficacy and feeding‐related complications of a nasojejunal feeding tube and jejunostomy after pancreaticoduodenectomy (PD) was investigated with a randomized, controlled clinical trial at the Affiliated Drum Tower Hospital. Methods: Sixty‐eight patients who underwent PD in the Department of Hepatobiliary Surgery were randomly divided into 2 groups: 34 patients received enteral feeding via a nasojejunal tube (NJT group) and 34 patients received enteral feeding via a jejunostomy tube (JT group). The assessment of clinical outcome was based on postoperative investigation of complications. The second part of the assessment included tube related complications and an index on catheter efficiency. Results: There were 15 cases with infectious complications in the JT group and 13 cases in the NJT group, and there was no significant difference in the rate of infectious complications between the 2 groups. The rate of intestinal obstruction and delayed gastric emptying was significantly decreased in the NJT group (P < .05). Catheter‐related complications were more common in the JT group as compared with the NJT group (35.3% vs 20.6%, P < .05). The time for removal of the feeding tube and nasogastric tube was significantly decreased in the NJT group. The postoperative hospital stay in the NJT group was significantly decreased (P < .05), and there was no hospital mortality in this study. Conclusion: Nasojejunal feeding is safer than jejunostomy, and it is associated with only minor complications. Nasojejunal feeding can significantly decrease the incidence of delayed gastric emptying and shorten the postoperative hospital stay.     

Placement of a Magnetic Small Bowel Feeding Tube at the Bedside

Background: Current methods of achieving postpyloric enteral access for feeding are fraught with difficulties, which can markedly delay enteral feeding and cause complications. Bedside tube placement has a low success rate, often requires several radiographs to confirm position, and delays feeding by many hours. Although postpyloric enteral tubes can reliably be placed in interventional radiology (IR), this involves greater resource utilization, delays, cost, and inconvenience. We assessed the utility of bedside enteral tube placement using a magnetic feeding tube (Syncro‐BlueTube; Syncro Medical Innovations, Macon, GA, USA) as a means to facilitate initial tube placement. Methods: We recorded the time to insertion, location of tube, success rate, and need for radiographs in a series of patients given magnetic feeding tubes (n = 46) inserted by our hospitalist service over an 8‐month interval. Results: Of the 46 attempted magnetic tube placements, 76% were successfully placed in the postpyloric position, 13% were in the stomach, and 11% could not be placed. In 83% of the magnetic tubes, only 1 radiograph was needed for confirmation. The median time to placement was 12 minutes (range, 4–120 minutes). Conclusion: The use of a magnetic feeding tube can increase the success rate of bedside postpyloric placement, decrease the time to successful placement, and decrease the need for supplemental radiographs and IR.     

Formulation of enteral diets for use in jejunal enteral feeding

Nasogastric enteral feeding is not tolerated in patients with gastric atony and in many critically-ill patients in whom gastric emptying may be delayed and in whom gastro-oesophageal regurgitation may lead to pulmonary aspiration of enteral feed and the development of pneumonia. Initial attempts to overcome these problems led to the development of post pyloric enteral feeding techniques with the infusion port of the tubes positioned in the duodenum. In many centres this technique is still the most practised post-pyloric enteral feeding technique. Nasoduodenal feeding tubes often retroperistalse into the stomach. The technique of choice, therefore, in these difficult patients is to position the infusion port of the feeding tube well distal to the ligament of trietz (post ligament of trietz nasojejunal enteral tube feeding). While nasogastric and nasoduodenal enteral feeding techniques have been shown to elicit a stimulatory exocrine pancreatic response, distal jejunal enteral feeding does not. During this mode of feeding the ileal brake is activated and pancreatic exocrine pancreatic secretion inhibited by the action of the released peptide YY and glucagon-like peptide-1 hormones, in turn the inhibition of pancreatic secretion being the result of inhibition of trypsin secretion. In the light of the findings showing the absence of a stimulatory pancreatic exocrine response to nasojejunal enteral feeding these patients should receive a predigested rather than a polymeric enteral diet.     

Placement of Nasoenteral Feeding Tubes Using Magnetic Guidance: Retesting a New Technique

Objective: To study a new technique of intubating the small bowel using a newly developed nasoenteral feeding tube fitted with a magnet in its tip and guided for placement with an external magnet.

Methods: The study was performed in medical and surgical wards of a university-affiliated Department of Veterans Affairs hospital on 42 patients referred by their attending physicians for tube placement. The newly designed feeding tube was inserted per nares into the stomach using traditional technique. As the tube was advanced, movement of the hand-held steering magnet was designed to guide the tip of the magnetic nasoenteral tube along the lesser curvature of the stomach, through the pyloric sphincter, and into the duodenum. Portable abdominal radiography confirmed the anatomic location of the tube tip.

Results: Fifty-one intubations were performed on 42 subjects. In 45 intubations (88%), tubes passed into the duodenum. Twenty-seven (53%) met criteria for optimal placement in the second portion of the duodenum or distally. Six of 11 tubes (55%) that were not optimally placed were advanced to the distal duodenum on repositioning. Median procedure time for the initial intubations was 30 minutes (interquartile range 15–40). Median procedure time for last 10 intubations improved to 13 minutes (interquartile range 5–20). No complications were related to the procedure.

Conclusions: Enteral feeding tube placement using external magnetic guidance is a promising, novel technique which is deserving of further study.     

Effect of feeding-tube properties on residual volume measurements in tube-fed patients

BACKGROUND: The effect of feeding tube size and port configuration on the ability to measure gastric residual volume (GRV) is poorly understood. In addition, there is confusion about the need to measure GRVs during feedings into the small bowel. This study sought to (1) compare the volume of gastric contents obtained from small-diameter feeding tubes and large-diameter sump tubes concurrently positioned in the stomach and (2) describe the distribution of GRVs during small-bowel feedings. METHODS: For the first objective, GRV measurements were made from 10-Fr tubes (n = 645) and 14-Fr or 18-Fr sump tubes (n = 645) concurrently present in 62 critically ill patients. Sixty-milliliter syringes were used to measure GRVs from the 10-Fr tubes; the fluid was returned to the stomach and measurements were repeated from the large-diameter sump tubes. To address the second research objective, 890 GRV measurements were made from 14-Fr or 18-Fr gastric sump tubes (not connected to suction) in 75 critically ill patients who were receiving small-bowel feedings. RESULTS: When GRVs were >50 mL, a linear regression equation indicated that volumes obtained from the large-diameter sump tubes were about 1.5 times greater than those obtained from the small-diameter tubes concurrently present in the stomach, p < .001. Gastric volumes > or =100 mL were found in 11.6% of the 890 measurements made in patients receiving small-bowel feedings; volumes > or =150 mL were found in 5.4% of the measurements. CONCLUSIONS: The findings suggest that GRVs obtained from large-diameter sump tubes are about 1.5 times greater than those obtained from 10-Fr tubes. Large GRVs occur in at least 5% of patients receiving postpyloric feedings.     

When Does Metoclopramide Facilitate Transpyloric Intubation?

Postpyloric feeding probably reduces the incidence of tracheobronchial aspiration and improves feeding tolerance. However, duodenal intubation is often unsuccessful in critically ill patients due to gastric atony. Metoclopramide improves gastric emptying. In a pilot study, 12 adult patients were administered 10 to 20 mg of intravenous metoclopramide after weighted nasal feeding tubes had failed to spontaneously pass distal to the pylorus. In no patient did metoclopramide induce transpyloric passage of the tube. A randomized prospective study involving 10 adult patients was conducted to examine the effect of preinsertion intravenous metoclopramide on transpyloric intubation. All patients had failed to achieve spontaneous duodenal intubation. Five patients received 20 mg of metoclopramide 10 min prior to nasal insertion of a weighed feeding tube. Five control patients received no premedication. Four metoclopramide patients achieved duodenal intubation immediately. In none of the control patients did transpyloric intubation occur (p = 0.048). Metoclopramide, administered after nasogastric intubation, is ineffective in promoting transpyloric advancement of feeding tubes. There is a significant increase in transpyloric intubation when metoclopramide is administered prior to tube insertion.     

A multicenter, prospective study of the placement of transpyloric feeding tubes with assistance of a magnetic device. The Magnet-Guided Enteral Feeding Tube Study Group

BACKGROUND: Placement of feeding tubes in the transpyloric position can be helpful in the management of enterally fed patients with pancreatitis, gastric atony, enterocutaneous fistulae, or pulmonary aspiration risk. The attainment of transpyloric position is difficult, and numerous techniques have been proposed to help in achieving this location. Recently, the use of a magnet-tipped feeding tube, dragged into proper position with an external magnet, has been described with an excellent success rate. METHODS: At 10 participating institutions, practitioners were trained in the use of the device. Successful tube placement was determined by abdominal radiograph. RESULTS: One hundred fifty-six tube placements were attempted. Transpyloric position was obtained in 60%. Placement into the third portion of the duodenum or distal was obtained in only 32%. Analysis of the data did not reveal a learning curve at the institutions, and 7 of 10 had a 50% or lower success rate. CONCLUSIONS: Placement of feeding tubes with the assistance of a magnetic device was infrequently successful at the majority of institutions where it was attempted. We report a lower success rate than the original article, which described an 88% success rate of transpyloric intubation. Although this technique has a high failure rate, some individuals seem to be very successful using it, which could reduce the need for endoscopy or transport for the placement of feeding tubes.     

Influence of unclogging agents on the surface state of enteral feeding tubes

Background: Despite standardized prevention procedures, recalcitrant clogging of enteral feeding tubes is observed, which requires recourse to varied unclogging agents. Some of these agents have proved effective in routine use, but their impact on the surface state of the tube materials has never been studied. In this work, the authors tested the impact of different unclogging agents on the materials used for these tubes (polyurethane and silicone). Methods: Enteral feeding tubes were placed in contact with different agents in vitro, and the surface state of the material was analyzed using 2 different methods: infrared spectroscopy and scanning electron microscopy. To assess the surface state of the silicone and polyurethane tubes, negative controls (undamaged tubes) and positive controls (deliberately damaged tubes) were used for each type. Results: The infrared spectroscopy method did not reveal any damage to the surface of either the silicone or the polyurethane tubes with either treatment. The test results by scanning electron microscopy showed that orange juice, pineapple juice, and cola had no detrimental action on the tube biomaterials under current conditions of clinical practice. Conclusions: Although some studies have advocated using polyurethane tubes to administer medication, silicone appears to be less vulnerable to damage by the agents tested.     

Efficacy of erythromycin for postpyloric placement of feeding tubes in critically ill children: a randomized, double-blind, placebo controlled study

BACKGROUND: Erythromycin enhances gastric emptying and has been suggested to facilitate nasoenteric feeding tube placement in adults. Our primary objective was to evaluate the effect of erythromycin on the transpyloric passage of feeding tubes in critically ill children, and second, to evaluate the effect of erythromycin on the distal migration of duodenal feeding tubes. METHODS: Seventy-four children were randomly assigned to receive erythromycin lactobionate (10 mg/kg) IV or equal volume of saline placebo 60 minutes before passage of a flexible weighted tip feeding tube. Abdominal radiographs were obtained 4 hours later to assess tube placement. If the tube was proximal to the third part of the duodenum, two additional doses of erythromycin/placebo were administered 6 hours apart. Those receiving additional doses had repeat radiographs 14 to 18 hours after tube placement. RESULTS: The number of postpyloric feeding tubes was similar in the erythromycin and placebo treated groups 4 hours after tube insertion (23/37 vs 27/37, p = .5). Of those with prepyloric tubes at 4 hours, none in the erythromycin group and 3 in the placebo group had the tube migrate to the postpyloric position by 14 to 18 hours (p < .05). Of those with postpyloric tubes proximal to the third part of the duodenum at 4 hours, additional doses of erythromycin did not cause more tubes to advance further into the intestine than did placebo (p = .6). CONCLUSIONS: Erythromycin does not facilitate transpyloric passage of feeding tubes in critically ill children. The distal migration of duodenal tubes further into the small bowel is also not enhanced by erythromycin.     

Monitoring bolus nasogastric tube feeding by the Brix value determination and residual volume measurement of gastric contents

BACKGROUND: Critically ill patients do not always tolerate nasogastric tube feeding. Gastric residual volumes (GRVs), obtained by aspiration from a nasogastric tube, are widely used to evaluate feeding tolerance and gastric emptying, but controversy exists about what constitutes the true GRV (diet formula or digestive juice) and how it should affect management. In this pilot study, we used the Brix value (BV) measurement of gastric contents to monitor both GRV and food content in patients receiving nasogastric feeding. METHODS: Forty-three patients receiving bolus nasogastric feeding were monitored for 24 hours before entry into the study and then divided into 2 groups according to traditional use of GRV; patients with low GRVs (< 75 mL) were placed in group 1, whereas patients with higher GRVs (> 75 mL) were placed in group 2. All subjects were given 250 mL of polymeric formula by bolus nasogastric infusion, followed by BV measurement of gastric contents at 0, 30, 60, 120, and 180 minutes. All gastric fluid was aspirated after 180 minutes of feeding; the volume was recorded and BV measurement made, then reinstilled with an added 30 mL of dilutional water, after which a final aspiration and BV measurement was performed. Calculated GRV and volume of formula remaining in the stomach was determined by derived equations. RESULTS: Serial BV measurements decreased in both groups after bolus feeding. For patients in group 2, the decrease was less such that at 180 minutes, the mean BV for gastric contents was significantly higher than for those patients in group 1 (10.1 vs 5.1, respectively; p < .01). Aspirated GRV, calculated GRV, and volume of formula remaining in the stomach at 180 minutes were significantly greater for patients in group 2 compared with those in group 1. Use of refractometry in combination with traditional use of GRV identified 4% (1/25) of patients in group 1 with low GRVs who might have possible gastric dysmotility (> 20% of initial 250-mL volume of formula remaining at 180 minutes) and ensured that 72% (13/18) of patients in group 2 with higher GRVs had sufficient gastric emptying (< 20% of initial 250 mL volume of formula remaining). CONCLUSION: This pilot study raises the feasibility that refractometry and the BV measurement of gastric juice may be a promising tool for bedside monitoring of tolerance and gastric emptying in patients receiving nasogastric feeding, providing valuable complementary information to traditional use of GRV.