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.     

Examination of Accuracy in the Assessment of Gastric Residual Volume

Background. Increased gastric content from enteral nutrition intolerance is thought to place patients at risk for pulmonary aspiration. Although considered a questionable practice, blind gastric tube aspiration is the most common approach to measure gastric content. This simulated study evaluated the accuracy of residual volume (RV) assessment via tube aspirations made from known volumes by controlling the syringe pull technique, feeding tube properties, fluid viscosity, and placement of tubes in the fluid. Materials and Methods. This study was conducted in a metrology laboratory. Aspirates were obtained using a force measurement test system to control force of the syringe pull technique using 3 different procedures (slow 10 inches per minute [ipm], intermittent 10 ipm, and fast 40 ipm). Four different feeding tubes, 10 Fr and 18 Fr, each made of polyurethane and polyvinyl chloride, were placed in varying depths of 100 mL of either water or formula. The effect of fluid viscosity was also examined. Results. Overall, 108 RVs were analyzed using a force measurement test system. Actual content of RV was underestimated 19% on average and varied across tube size and viscosity. Intermittent and slow syringe pull techniques yielded greater aspirate quantities, although neither technique aspirated the full amount of volume available. The 10 Fr feeding tubes yielded larger RVs in more viscous fluid, yet the 18 Fr tubes performed better with fluids of lower viscosity. Conclusions. Based on this simulation, RV assessment does not accurately reflect the total volume of the contents available and, therefore, the clinical utility of this assessment should be further investigated.     

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.     

Improved design of nasogastric feeding tubes

Disappointed with the overall performance of weighted and unweighted nasogastric feeding tubes, a design programme was initiated which resulted in the development of two new nasogastric tubes, one weighted and one unweighted. The tubes were manufactured with polyurethane rather than polyvinylchloride (PVC) which permitted an increase in diameter of the internal lumen which in turn was coated with water activated lubricant to ease removal of the introducer wire. A specially modelled outflow port was incorporated into the tips of both tubes. The performance of the two new polyurethane nasogastric feeding tubes was assessed under controlled trial condition using as a reference a widely used PVC unweighted open ended tube. While intubation times were similar in patients without concurrent endotracheal intubation, it took a significantly shorter time to intubate patients with concurrent endotracheal intubation with the new weighted tube. Following tube intubation, it was possible to aspirate gastric contents significantly more often through the new polyurethane tubes (p < 0.001) than through the PVC tube, and the unweighted polyurethane tube stayed in situ longer (p < 0.05) than the PVC tube. The newly designed polyurethane nasogastric feeding tubes are the first tubes that have been shown to have advantages over the simpler type of open ended, unweighted PVC nasogastric feeding tubes.     

Endoscopic placement of fine bore nasogastric and nasoenteric feeding tubes

In a small proportion of patients requiring enteral nutrition it may not be possible to site nasogastric or nasoenteric feeding tubes using standard intubation techniques. We describe an endoscopic method of tube placement applicable not only for positioning nasogastric feeding tubes in patients with coexisting oesophageal pathology, but also for placement of nasoenteric feeding tubes when disordered gastric emptying is present.     

床旁放置经鼻小肠管的新方法

胃排空障碍是影响危重患者肠内营养实施的重要问题,经小肠喂养是解决方法之一。放置小肠营养管的非手术方法主要包括内镜引导和X线辅助,但这两种方法均需要一定的设备和场所,不利于对危重患者进行床旁实施。近年来出现了多种辅助盲探放置小肠管的新方法,本文对这些方法进行综述。     

Determination of a practical pH cutoff level for reliable confirmation of nasogastric tube placement

Background: Enteral feeding is a common method of nutrition support when oral intake is inadequate. Confirmation of correct nasogastric (NG) tube placement is essential. Risks of morbidity/mortality associated with misplacement in the lung are well documented. Studies indicate that pH ≤4 confirms gastric aspirate, but in pediatrics, a pH of gastric aspirate is often >4. The goal of this study was to determine a reliable and practical pH value to confirm NG tube placement, without increasing the risk of not identifying a misplaced NG tube. Methods: Pediatric inpatients older than 4 weeks receiving enteral nutrition (nasogastric or gastrostomy) were recruited over 9 months. Aspirate samples were pH tested at NG tube placement and before feedings. If pH >4, NG tube position was confirmed by chest radiograph or further investigations. In addition, intensive care unit (ICU) patients who required endotracheal suctioning were recruited, and endotracheal aspirate samples were pH tested. Results: A total of 4,330 gastric aspirate samples (96% nasogastric) were collected from 645 patients with a median (interquartile range [IQR]) age of 1.0 years (0.3–5.2 years). The mean (standard deviation [SD]) pH of these gastric samples was 3.6 (1.4) (range, 0–9). pH was >4 in 1,339 (30.9%) gastric aspirate samples, and of these, 244 were radiographed, which identified 10 misplaced tubes (1 with pH 5.5). A total of 65 endotracheal aspirate samples were collected from 19 ICU patients with a median (IQR) age of 0.6 years (0.4–5.2 years). The mean (SD) pH of these samples was 8.4 (0.8) (range, 6–9.5). Conclusion: Given that the lowest pH value of endotracheal aspirate sample was 6, and a misplaced NG tube was identified with pH 5.5, it is proposed that a gastric aspirate pH ≤5 is a safer, reliable, and practical cutoff in this population.     

Treating Delayed Gastric Emptying in Critical Illness

Background: We describe experience using the Cortrak nasointestinal feeding tube and prokinetics in critically ill patients with delayed gastric emptying. Methods: Patient cohorts fed via a Cortrak electromagnetically guided nasointestinal tube (EGNT) or 14 French‐gauge nasogastric tube plus prokinetics were retrospectively compared. Results: Of 69 EGNT placements in 62 patients, 87% reached the small intestine. The median percentage of the enteral nutrition goal increased from 19% pre‐EGNT to 80%–100% between days 1 and 10 post‐insertion and was greater than in 58 patients prescribed metoclopramide (40%–87%: days 1–2, 5–7, P ≤ .018) or 38 patients prescribed erythromycin (48%–98%; days 1 and 5, P < .0084). Up to day 10, the cumulative feeding days lost were lower for EGNT (1.06) than for metoclopramide (2.6, P < .02) or erythromycin (3.1, P < .02). The EGNT group had a lower use of prokinetics and lower treatment cost. Conclusion: Most bedside EGNT placements succeed and, compared to nasogastric feeding plus prokinetics, increase enteral nutrition delivery and reduce both cumulative feeding days lost and prokinetic use.     

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.     

Clinical evaluation of a newly designed nasogastric enteral feeding tube

Concerned with reports in the literature of a rising incidence of enteral feeding tube clogging, we initiated a design programme in an attempt to improve the clinical efficacy of nasogastric and nasoenteric enteral feeding tubes. Tube design has been based on a remodelling of the outflow part of a polyurethane feeding tube previously developed in our unit. The tip of the newly designed 8F enteral feeding tube is shorter in length with a rounded end to minimize discomfort during intubation. The port itself incorporates a tapered outflow design with the side walls now extending below the mid-point of the internal flow lumen resulting in a 28% increase in port area compared to the equivalent and originally designed tube. The performance of the newly designed polyurethane feeding tube was assessed under controlled trial conditions using as references two widely used 8F polyurethane nasogastric feeding tubes whose design has been based on different principles (Flexiflo, weighted tip, open-ended with two side ports; Freka, occluded tip, two simple large side ports). Eighty-eight of 90 patients entered into the study were successfully intubated with no significant differences being noted in intubation times in the three groups. Significantly less discomfort occurred during intubation of patients with the Radius tube as compared to the Freka tube (P < 0.05). Although there were no clear differences between the Flexiflo and Freka tubes either in regard to the number of attempts required for intubation or aspiration or discomfort during intubation or ease of aspiration, fewer attempts at insertion and aspiration were needed and intubation and aspiration were easier for patients randomised to the Radius group than those to the Flexiflo and Freka groups (P < 0.05). We conclude that the clinical performance of the newly designed Radius enteral feeding tube compares favourably with that of the reference tubes. Only one of the new tubes (3.3%) blocked during the course of the study. High rates of non-elective extubation were observed in the three study groups (Radius 80.0%, Flexiflo 73.3%, Freka 73.3%). Design modifications are unlikely to influence non-elective nasogastric feeding tube extubation rates which remain a major clinical problem.     

腹内压联合胃残余量监测在ICU患者护理中的应用

目的：探讨腹内压（Intra－abdominal pressure，IAP）联合胃残余量监测在重症监护病房（intensive care unit， ICU）患者早期肠内营养耐受性观察中的作用。方法分析2013年186例入住ICU并且实施肠内营养的危重患者，随机分成试验组和对照组各93例。分别采用腹内压联合胃残余量监测方案和常规护理措施。比较两组腹胀、呕吐、腹泻的发生率和目标喂养量的达标率。结果试验组腹胀的发生率为26．88％，对照组腹胀的发生率为55．91％（ P＜0．01），差异有显著统计学意义；试验组呕吐的发生率为9．68％，对照组呕吐的发生率为21．50％（P＜0．05），差异有统计学意义；试验组腹泻的发生率为8．60％，对照组腹泻的发生率为10．75％（P＞0．05），差异无统计学意义；两组患者均达到目标喂养量，试验组目标喂养量达标率为88．17％，对照组目标喂养量达标率为86．02％，差异无统计学意义。结论腹内压联合胃残余量监测方案可以有效降低ICU患者早期肠内营养腹胀、呕吐的发生率，使其早日达到目标喂养量，对于提高患者早期肠内营养耐受性有重要意义。     

早期肠内营养在大面积脑梗死病人应用的研究

目的:评价EEN对大面积脑梗死病人治疗的有效性. 方法:将61例大面积脑梗死病人随机分成EEN组和对照组.比较病人入院后3周的病死率、神经功能缺损评分、并发症发生率和营养状况等. 结果:EEN组病死率和并发症的发生率,均低于对照组,而神经功能缺损评分和营养状况优于对照组. 结论:早期给予EN,可降低大面积脑梗死病人的病死率和并发症的发生率,改善机体营养状况,促进机体神经功能恢复.     

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.     

Esophagogastric decompression and enteral feeding following cholecystectomy: a controlled, randomized prospective trial

One hundred fourteen patients scheduled to undergo elective cholecystectomy were prospectively randomized into one of four treatment groups to study the potential benefits of esophagogastric decompression with and without immediate postoperative enteral nutrition. Group I was the control, and patients received only iv fluids and were allowed to eat as tolerated. Group II patients received iv fluids and esophagogastric decompression. Group III patients received esophagogastric decompression and enteral sterile water through the duodenal feeding lumen. Group IV patients received esophagogastric decompression and infusion of an elemental diet through the feeding lumen. The surgical techniques were standardized for all patients. The results of the study indicated no statistically or clinically significant differences among any of the treatment groups regarding; (1) need for parenteral analgesics or antiemetics, (2) tolerance of regular diet, (3) postoperative day of discharge, and (4) postoperative day that other discharge criteria were met. It is concluded that there is no objective benefit to the routine use of esophagogastric decompression with or without enteral nutrition in elective cholecystectomy patients.     

鼻肠管在伴有胃出口梗阻的胃癌病人营养和化疗中的应用

目的:探讨经内镜放置鼻肠管给予肠内营养(EN)在伴有胃出口梗阻的胃癌病人新辅助化疗中的应用及疗效。方法:对16例伴有胃出口梗阻的胃癌病人经内镜放置鼻肠管并给予EN,观察该方法的安全性和有效性。结果:16例病人均成功经内镜放置鼻肠管,平均置管时间为(10.8±3.6)min,未发生消化道穿孔和出血等严重并发症。所有病人均顺利完成新辅助化疗,并在化疗结束后接受了手术。结论:经内镜放置鼻肠管行EN,能改善伴有胃出口梗阻胃癌病人的营养状况,帮助其完成新辅助化疗。     

Nasogastric tube feeding and percutaneous endoscopic gastrostomy tube feeding in patients with head and neck cancer

Background: For patients with a diagnosis of head and neck cancer, oral nutrition may not provide adequate nutrition during radical radiotherapy or chemoradiation treatment, resulting in enteral feeding initiation. Enteral feeding may be delivered via a nasogastric tube or by a gastrostomy tube. The present study aimed to determine how different treatment modalities impact on requirement for enteral feeding and which method of enteral feeding provided the most benefit to the patient, as demonstrated by weight loss and the number of unscheduled radiotherapy treatment interruptions. Methods: Patients who were treated with radical radiotherapy or chemoradiation between January 2004 and June 2007 were reviewed retrospectively (n = 196, male = 149, female = 47). Data were collected on demographics, diagnosis, T and N classification, nutritional status, unscheduled radiotherapy treatment interruptions, and type and duration of enteral feeding. Subjects were divided into three subgroups depending on the treatment received. Comparisons were then made between methods of enteral feeding. Results: Combined modality treatment (Induction Chemotherapy and Chemoradiation) results in a higher proportion of patients requiring enteral feeding (66–71% compared to 12% for radiotherapy). Patients fed via a prophylactic percutaneous endoscopic gastrostomy lost the least amount of weight during treatment (?4.6% to +1.4%), although the method of enteral feeding did not statistically influence weight difference at the end of treatment. The enteral feeding method did not influence unscheduled radiotherapy treatment interruptions. Conclusions: Combined modality treatment results in a greater requirement for enteral feeding, with these patient groups having the greatest weight loss. The findings obtained in the present study indicate that the method of enteral feeding did not statistically influence weight loss at the end of treatment or unscheduled radiotherapy treatment interruptions.     

The paracetamol absorption test: a useful addition to the enteral nutrition algorithm?

BACKGROUND: Enteral nutrition in critically ill patients given via the nasogastric route is often decreased or stopped because of large gastric residual volumes. AIM: To assess the effect of continuing enteral nutrition in patients with an elevated gastric residual volume but normal gastric emptying by the paracetamol absorption test. METHODS: The paracetamol absorption test was performed on all patients receiving enteral nutrition via a nasogastric tube who had a residual volume (assessed every 8 hours) of >150 ml or more than twice the hourly infusion rate. Patients were then divided into 2 groups according to the result of the test: Group 1 (n=8), normal gastric emptying; and Group II (n=24), abnormal gastric emptying. Group I continued to receive enteral nutrition. In Group II feeding was interrupted in 18 patients and prokinetic agents administered, while a subgroup of six patients continued to receive enteral nutrition without prokinetic agents. All patients were followed for evidence of delayed gastric emptying and aspiration. RESULTS: Residual volumes were similarly elevated in both groups (p=0.25). Enteral nutrition was continued in Group I with no adverse effects. Prokinetic agents allowed enteral nutrition to be resumed in 88% of the 18 Group II patients. Enteral nutrition in the subgroup had to be stopped because of persistently elevated residual volumes. CONCLUSION: The paracetamol absorption test may be normal in patients with relatively high gastric residual volumes. These patients may continue to receive enteral nutrition.     

Quand et comment nourrir l'intestin agressé ?

Nutritional support with enteral nutrition in intensive care patients is highly desirable for many reasons, but it is often difficult to realise. Critically ill patients suffer pylorus closure and reduced peristaltism due to mechanical ventilation and use of drugs like opiates, sedatives and catecholamines. Feeding through nasogastric tubes is the simplest technique. In case of failure, defined as persistent gastric residues > 300 mL or negative energy balances (delivering less than 75% of energy target for > 3 days), postpyloric feeding should be introduced. Daily energy delivery should be closely monitored to avoid progressive large negative energy balances: indeed, enteral nutrition is frequently interrupted in ICU patients for various therapeutic and diagnostic procedures. Combined enteral and parenteral nutrition can avoid the dire consequence of deficient energy intakes. Enteral nutrition may be initiated early in most categories of medical and surgical patients: the clinical benefits of this approach have been demonstrated in trauma and burn patients, but not yet in other diagnostic categories. In most patients, especially in the more stable patients, nutritional support may be introduced between 3 and 5 days post-admission. In the ICU, delivery is best performed with the continuous pump-controlled infusion technique. To be successful, nutrition must become a routine, supported by structured protocols.     

Clinical efficacy and design changes of "fine bore" nasogastric feeding tubes: a seven-year experience involving 809 intubations in 403 patients

We report here our clinical experiences of "fine bore" nasogastric feeding tubes. Data have been collated over a 7-year period (1978-1985). A total of 403 patients were intubated on 809 occasions. In the first retrospective study, the clinical use of 491 unweighted tubes was compared with that of fifty 3.5-g weighted tubes. No advantage was found in the use of the weighted tubes. In the second prospective controlled clinical trial, these results were confirmed. Forty-six patients were intubated on 76 occasions with an 85-cm open-ended, unweighted nasogastric feeding tube (Prima, Portex UK), and 57 patients were intubated on 79 occasions with a 91-cm 3.0-g weighted tube (Entriflex, Biosearch, Raritan, NJ). Mean duration of placement was similar in each case, and 62% of both types of tubes were inadvertently removed. Without exception, all the tubes remained in the stomach throughout. Disappointed with the similar and overall performance of both types of tubes, we initiated a design program which resulted in the development of two new nasogastric tubes, one weighted and one unweighted. The tubes were manufactured with polyurethane, rather than polyvinylchloride (PVC), which permitted an increase in diameter of the internal lumen which, in turn, was coated with water-activated lubricant to ease removal of the introducer wire. A specially modeled outflow port was incorporated into the tips of both tubes. The performance of the two new polyurethane nasogastric feeding tubes was assessed under controlled trial conditions; as a reference, a widely used PVC unweighted open-ended tube was used.(ABSTRACT TRUNCATED AT 250 WORDS)     

Experience of post-pyloric feeding in seriously ill patients in clinical practice

BACKGROUND: Maintaining nutrition is an integral part of patient care and when it is possible enteral nutrition is regarded as superior to parenteral nutrition. Post-pyloric feeding may enable enteral feeding to be maintained in patients who cannot tolerate nasogastric feeding. The success of post-pyloric feeding in routine clinical practice is uncertain. METHODS: One hundred and forty six consecutive patients who had 150 separate episodes of post-pyloric feeding were identified. Casenotes were reviewed to assess indication for post-pyloric feeding, prior use of alternative methods of feeding, success of achieving nutritional requirements and patient outcome. RESULTS: A post-pyloric tube was successfully placed in 138 (92%) and nutritional requirements were met by post-pyloric feeding alone in 124 (83%). Post-pyloric feeding was used for between 2 and 254 days (median 14 days). Conditions for which post-pyloric feeding was used to administer nutritional support included burn injury, pancreatitis, sepsis, post-operative gastric stasis, bone marrow transplantation and chemotherapy induced vomiting. Fifty (33%) patients had an attempt at nasogastric feeding and 33 (22%) were on total parenteral nutrition before post-pyloric feeding was commenced. There was one major complication of a jejunal ulcer bleed in the series. Minor complications included displacement of the nasojejunal tube and failure to absorb feed related to gastrointestinal dysfunction. CONCLUSIONS: Post-pyloric feeding can be successfully used to maintain enteral nutrition in patients who would otherwise require parenteral nutrition.