Methods to test feeding tube placement in children

PURPOSE: This replication study examined the extent to which feeding-tube aspirates (pH and enzyme content) are effective predictors of feeding tube location in acutely ill children. STUDY DESIGN AND METHODS: A convenience sample of 56 children was obtained at a metropolitan children's hospital. Approximately 2.5 ml of fluid were withdrawn from children's nasogastric, orogastric, or nasointestinal tubes within 30 minutes of radiographic examination. Fluid was tested for pH and enzymes, and results were compared with radiographic results of tube location. RESULTS: Mean gastric pH was significantly lower than mean intestinal pH. Mean fasting gastric pepsin level was significantly higher than mean fasting intestinal pepsin level. Usual intestinal constituent, trypsin, was significantly higher in the small bowel than in the stomach. Mean fasting trypsin level was 70 microg/ml in the intestine, and only 10 microg/ml in the gastric site. Predictive positive value was >90% for all tests; predictive negative value was < 65%. Colors of the gastric aspirates were distinctly different from those observed in intestinal aspirates. CLINICAL IMPLICATIONS: Methods of aspirating fluid from feeding tubes and testing visually or assaying for aspirate characteristics were found to be adaptable from adults to children. The clinical implications of being able to use a test as simple as pH of feeding aspirates means that nurses can easily test these aspirates in any clinical setting using reliable pH test strips, similar to what was done in this study. These data add evidence that suggests indicators of tube location effective in adults are also effective in children.     

Indicators of postpyloric feeding tube placement in children

OBJECTIVE: To determine the validity of five indicators (color, pH, and concentrations of bilirubin, pepsin, and trypsin in aspirated gastrointestinal secretions) in predicting postpyloric placement of feeding tubes in critically ill children. DESIGN: Prospective, observational study. SETTING: University teaching hospital. PATIENTS: A total of 96 gastrointestinal aspirates were obtained from 53 children requiring placement of a nasoenteric feeding tube. INTERVENTIONS: Feeding tubes were aspirated by applying suction with a 20-mL syringe. Repeat aspirates from the same patient were obtained on different days. All aspirations were performed within 30 mins of obtaining a radiograph to assess tube position. MEASUREMENTS AND MAIN RESULTS: Aspirates were inspected visually for color. pH and bilirubin concentrations were determined at the bedside by using reagent strips. Pepsin and trypsin concentrations were measured spectrophotometrically in a research laboratory. The sensitivity, specificity, predictive values, and efficiency for each indicator and their 95% confidence intervals were determined based on the position of the feeding tube on the radiograph. Aspirate pH > or =6 had the lowest positive predictive value (76%, range 67% to 85%) but high negative predictive value (94%, range 89% to 99%) for determining postpyloric positioning of the feeding tube. Bilirubin concentration > or =5 mg/dL (> or =86 micromol/L) had the highest positive predictive value (96%, range 91% to 100%) and lowest negative predictive value (88%, range 81% to 95%). Overall efficiency was best for the appearance of a clear yellow aspirate color (93%, range 88% to 98%), pepsin concentration < or =20 microg/mL (94%, range 89% to 99%), and trypsin concentration > or =50 microg/mL (94%, range 89% to 99%). CONCLUSIONS: Simple bedside assessment of gastrointestinal aspirate color, pH, and bilirubin concentration is useful for predicting feeding tube position. Use of these tests may reduce the number of radiographic studies needed to confirm postpyloric positioning. Laboratory-determined pepsin and trypsin concentrations predict tube position with a high degree of accuracy. Development of simple and inexpensive bedside tests for the detection of gastrointestinal enzymes may be useful.     

Effectiveness of pH measurements in predicting feeding tube placement

The extent to which pH values of aspirates from feeding tubes could be used to differentiate between (a) gastric and intestinal placement, and (b) gastric and respiratory placement were determined in a clinical study. The sample consisted of 181 adult subjects, 94 with small-bore nasogastric tubes and 87 with nasointestinal tubes. Data were collected at the time of initial tube placement and again, when possible, after one or two days of tube feedings. Using color coded pH-paper, a total of 247 readings were made concurrently with x-rays to determine feeding tube position. Findings indicated that pH readings were often effective in differentiating between gastric and intestinal placement (p less than .0001). For example, approximately 81% of the aspirates from nasogastric tubes had pH values ranging from 1 through 4, while almost 88% of the aspirates from nasointestinal tubes had pH values of 6 or greater. Only one aspirate from a tube inadvertently placed in the lung was tested; as expected it had an alkaline pH.     

Development of a reliable and valid bedside test for bilirubin and its utility for improving prediction of feeding tube location

BACKGROUND: The addition of laboratory bilirubin readings to an algorithm based on pH alone improves prediction of feeding tube location; although reliable pH-teststrips are available, there is no bedside test to measure bilirubin in feeding tube aspirates. OBJECTIVES: This study was designed to test the efficacy of a bilirubin teststrip with a newly developed scale in measuring the bilirubin content in feeding tube aspirates, and to determine the effectiveness of a combination of readings from pH and bilirubin teststrips in predicting feeding tube location. METHODS: A total of 631 gastrointestinal specimens for concurrent pH and bilirubin testing were obtained from adult, acutely ill patients with newly inserted feeding tubes (nasogastric, n = 328; nasointestinal, n = 303) within 5 minutes of radiographs taken to determine tube location. In addition, 225 respiratory specimens were tested. Bilirubin was measured with a teststrip incorporating a newly developed colorimetric visual bilirubin (VBIL) scale, and by a laboratory assay. pH was measured with a teststrip and a pH-meter. Results from the bilirubin and pH tests were read by research assistants and staff nurses and compared with tube location as determined by radiography. RESULTS: The correlation between readings made from the 5-point VBIL scale and the trimmed laboratory bilirubin was 0.93, with dichotomized readings correlating 0.87 and kappa equal to 0.86. A pH greater than 5 and a bilirubin less than 5 mg/dL successfully identified 100% of the 225 respiratory cases. In the category of pH 5 or less and bilirubin less than 5 mg/dL, 98% of the cases were gastric cases. In the category of pH greater than 5 and bilirubin 5 or higher mg/dL, nearly 88% of the cases were intestinal cases. CONCLUSIONS: The newly developed VBIL scale is effective in determining the bilirubin content in feeding tube aspirates. Furthermore, compared with predicting tube location from pH-paper alone, dichotomized readings from the VBIL scale/bilirubin teststrip used in combination with a pH-teststrip improved the ability to differentiate between respiratory and gastrointestinal tube placement, as well as between gastric and intestinal tube placement. Refinement of the VBIL scale is indicated to increase its accuracy.     

The performance of infants born preterm and full-term in the mobile paradigm: learning and memory

BACKGROUND AND PURPOSE: By 3 to 4 months of age, infants born full-term and without known disease display associative learning and memory abilities in the mobile paradigm, where an infant's leg is tethered to a mobile such that leg kicks result in proportional mobile movement. The first purpose of this study was to examine the learning and memory abilities of a group of infants born full-term compared with those of a comparison group. Little is known about the learning and memory abilities in infants born preterm, a group at known risk for future impairments in learning and movement. The second purpose of this study was to determine if and when an age-adjusted group of infants born prematurely display associative learning and memory abilities over a 6-week period. SUBJECTS: Ten infants born full-term (38-42 weeks gestational age [GA]) and 10 infants born preterm (<33 weeks GA and <2,500 g) who were tethered and had control over the mobile movement were independently compared with a comparison group of 10 infants born full-term who were tethered and viewed a moving mobile but did not have control over the mobile movement. Infants in all 3 groups were seen at 3 to 4 months of age and were excluded from participation for any known visual or orthopedic diagnoses. METHODS: Infants were tested using the mobile conjugate reinforcement paradigm, where one leg is tethered to an overhead mobile such that kicking with that leg results in proportional mobile movement. The kicking rates of the full-term group and the preterm group were compared with their own initial (baseline) kicking rates and with those of the comparison group. RESULTS: After exposure to the conjugate relationship between kicking and mobile movement, the full-term group kicked more frequently compared with their own baseline levels and compared with the comparison group, fulfilling both criteria for learning and memory. In contrast, the preterm group did not increase their kicking rate according to both criteria. DISCUSSION AND CONCLUSION: These results suggest that infants born prematurely differ in their performance in the mobile paradigm as compared with age-matched infants born full-term. The mobile paradigm may provide clinicians with an important early assessment of infants' associative learning and memory abilities. Follow-up studies are needed, however, to further validate this paradigm as a clinical assessment tool.     

A review of the nursing care of enteral feeding tubes in critically ill adults: part I

Enteral tubes are frequently used in critically ill patients for feeding and gastric decompression. Many of the nursing guidelines to facilitate the care of patients with enteral tubes have not been based on current research, but on ritual and opinion. Using a computerised literature search and an evidence-based classification system as described by the Joanna Briggs Institute for Evidence Based Nursing and Midwifery (JBI), a comprehensive review was undertaken of enteral tube management. Several nursing practices related to enteral tube management are described. Evidence to support alternate methods of tube placement assessment other than abdominal X-ray was inconclusive. Enteral feeding should continue if gastric residual volumes are not considered excessive, as feeding is often withheld unnecessarily. Frequency of checking gastric residual volumes is largely opinion based and varies considerably, but prokinetics that aid gastric emptying should be used if absorption of feeds is problematic. Other recommendations include continuous rather than intermittent feeding, semi-recumbent positioning to reduce the risk of airway aspiration and diligent artificial airway cuff management. Contamination of feeds can be minimised by minimal, meticulous handling and the use of closed rather than open systems. Generally, there was little high quality evidence to support practice recommendations leaving significant scope for further research by nurses in the management of patients with enteral tubes.     

A review of the nursing care of enteral feeding tubes in critically ill adults: part II.

Enteral tubes are frequently used in critically ill patients for feeding and gastric decompression. Many of the nursing guidelines to facilitate the care of patients with enteral tubes have not been based on current research, but on ritual and opinion. Using a computerised literature search and an evidence-based classification system as described by the Joanna Briggs Institute for Evidence Based Nursing and Midwifery (JBI), a comprehensive review was undertaken of enteral tube management. Several nursing practices related to enteral tube management are described. Evidence to support alternate methods of tube placement assessment other than abdominal X-ray was inconclusive. Enteral feeding should continue if gastric residual volumes are not considered excessive, as feeding is often withheld unnecessarily. Frequency of checking gastric residual volumes is largely opinion based and varies considerably, but prokinetics that aid gastric emptying should be used if absorption of feeds is problematic. Other recommendations include continuous rather than intermittent feeding, semi-recumbent positioning to reduce the risk of airway aspiration and diligent artificial airway cuff management. Contamination of feeds can be minimised by minimal, meticulous handling and the use of closed rather than open systems. Generally, there was little high quality evidence to support practice recommendations leaving significant scope for further research by nurses in the management of patients with enteral tubes.     

Effect of feeding tube properties and three irrigants on clogging rates

An experimental study was conducted on 3 consecutive 12-hour days to determine if selected physical properties of feeding tubes (material and diameter) affect tube clogging. Effectiveness of three irrigant fluids (cranberry juice, Coca-Cola, and water) in preventing tube clogging was studied. One hundred eight tubes were connected to gravity flow feeding bags containing isotonic enteral formula; 54 polyurethane and 54 silicone tubes were equally divided as to external diameters of 8 French (Fr), 10 Fr, and 12 Fr. At 4-hour intervals, flow regulators on the feeding bags were adjusted to a rate of 50 ml/hour. Fluid volumes delivered per minute were measured for each tube at 2-hour intervals. One set of tubes at each station was irrigated periodically with cranberry juice, Coca-Cola, or water. On each of the 3 days, analyses revealed significant, p less than .05, effects for tube material, cranberry juice contrasted with Coca-Cola and water as irrigants, and time. Polyurethane was consistently superior to silicone as a tube material, and cranberry juice was consistently inferior to both Coca-Cola and water as an irrigant. Tube diameter had no significant effect on the incidence of tube clogging.     

Factors associated with the transition to oral feeding in infants fed by nasogastric tubes

Following a review of 100 infants fed by nasogastric tubes, medical factors associated with the length of transition to complete oral feeding were identified through correlational and multiple regression analyses. Six of the 100 infants had an extremely lengthy transition or never progressed to oral feeding; the remaining 94 infants progressed to oral feeding within 2 to 58 days. The total number of medical complications correlated significantly and positively with the length of transition. Digestive, respiratory, and cardiac complications were all significant predictors of the length of transition to oral feeding. The results of this study may assist occupational therapists in earlier identification of and intervention for infants fed by nasogastric tubes who are at risk for later oral feeding problems and a longer transition from nasogastric tube to oral feeding.     

Comparison of 2 methods of managing gastric residual volumes from feeding tubes.

BACKGROUND: Research-based standards do not exist for the management of gastric residual volumes from feeding tubes. Withdrawing and returning residual volumes can lead to clogged tubes and exposes patients to possible contamination of the feeding system. However, discarding residual volumes may place patients at risk for electrolyte imbalance and may alter fluid or nutritional balance. OBJECTIVES: To investigate the effects of discarding versus returning gastric residual volumes on body weight, serum electrolyte levels, and the rate of complications associated with tube feeding. METHODS: Thirty-five subjects receiving enteral feedings were recruited from intensive care units at 3 Midwest hospitals and randomized to a discard group or a return group. Eighteen sets of usable data were obtained. RESULTS: Repeated-measures analysis of variance indicated no significant differences between the 2 groups for any of the variables. Complications related to enteral feedings were more common in the return group (n = 8), which had 2 episodes of tube clogging and 1 episode of diarrhea and nausea. None of these complications were experienced by patients in the discard group (n = 10). CONCLUSIONS: Both groups had significant numbers of complications, including a total of 15 episodes, 7 in the discard group and 8 in the return group, of feeding delays due to high gastric residual volumes. Although serum electrolyte levels did not differ significantly between the 2 groups, potassium levels tended to be lower in the discard group. Considerations for the care of critically ill patients with feeding tubes are discussed in light of these findings.     

Magnetic resonance imaging of the newborn brain: manual segmentation of labelled atlases in term-born and preterm infants

Premature birth is a major and growing problem. Investigations into neuroanatomical correlates and consequences of preterm birth are hampered by complex neonatal brain anatomy and unavailability of atlases and protocols covering the whole brain. We developed delineation protocols for the manual segmentation of cerebral magnetic resonance (MR) images from newborn infants into 50 regions with comprehensive coverage of the brain. We then segmented MR scans from 15 infants born preterm at median 29, range 26-35, weeks postmenstrual age and scanned at term-corrected age, and five term-born infants born at median 41, range 39-45, weeks postmenstrual age. Total and regional brain volumes were estimated in each infant, and regional volumes expressed as a fraction of total brain volume. Total brain volumes were higher with greater age at birth and at time of scan, but once corrected for age at scan there was no difference between preterm and term infants. Fractional age-corrected regional volumes were bigger unilaterally in terms in middle and inferior temporal gyri, anterior temporal lobe, fusiform gyrus and posterior cingulate gyrus. Fractional age-corrected regional volumes were larger in preterms bilaterally in hippocampus, amygdala, thalamus and lateral ventricles, left superior temporal gyrus and right caudate nucleus. These differences were not significant after correcting for multiple hypothesis testing, but suggest subtle differences between preterms and term-borns accessible to regional analysis. Detailed illustrated protocols are made available in the Appendix.     

Enteral feedings with comfort and safety

Patients who are unable to eat by mouth can be fed in a manner that maintains the structural and functional integrity of the gastrointestinal tract. The appropriate choice of type of feeding tube to use is based on the reasons patients need to be tube fed and the expected duration of need for the tube. Once the tubes are placed, verification of placement is critical for safe use. Patients, family caregivers, and staff must assess for potential complications. Misplacement is the most common problem of feeding tubes. Life-threatening complications can include "refeed syndrome" and "buried bumper syndrome." Additional threats include contaminated tube feeding and inappropriate medication administration. Feeding too rapidly into the small intestine can cause necrosis of the small bowel. To maintain patient comfort, site care is critical. Nasogastric tubes can cause permanent deformity of the nares. Gastric drainage on the skin can cause painful excoriation that is difficult to manage. With careful monitoring of tube feedings, positive nutritional status can be achieved. A positive nutritional status assists in promoting health and immune function.     

Impact of blood sampling in very preterm infants

In a prospective investigation, 99 very preterm infants (gestational age (GA) 24 32 weeks, birthweight 560-2,255 g) were studied during the first 4 weeks of life. The infants were divided into two groups: infants born extremely early (GA <28 weeks, n = 20) and infants of GA 28 - 32 weeks; the groups were then subdivided into critically ill or not. Diagnostic blood sampling and blood transfusion events were recorded. In total, 1905 blood samples (5,253 analysis) were performed, corresponding to 0.7 samples (1.9 analysis) per day per infant. The highest frequencies were found during the first week, in infants with extremely low GA and in critically ill infants. The mean blood loss and transfusion volume values were 13.6 ml/kg and 6.3 ml/kg, respectively. In total, 19 infants (19%) received 34 transfusions corresponding to 0.3 transfusions per infant. Thirteen out of 20 infants of extremely low GA received 28 blood transfusions, corresponding to 27.0 ml/kg of blood on average during the study period. Four developed late anaemia; thus, in total, 14 (70%) of the infants born extremely early received 35 transfusions during the first 3 months of life, corresponding to a total mean of 34.8 ml/kg. For the extremely preterm infants a significant correlation between sampled and transfused blood volume was found (mean 37.1 and 33.3 ml/kg, respectively, r = + 0.71, p = 0.0003). The most frequently requested analyses were glucose, sodium and potassium. Few blood gas analyses were requested (1.9/ infant). No blood losses attributable to excessive generous sampling were detected. The results show an acceptable low frequency of sampling and transfusion events for infants of GA 28-32 weeks. The study emphasizes the necessity of thorough reflection and monitoring of blood losses when ordering blood sampling in extremely preterm, critically ill infants.     

A novel method for insertion of post-pyloric feeding tubes at the bedside without endoscopic or fluoroscopic assistance: a prospective study

Objective To assess a novel method, adapted from already published literature, for bedside placement of nasojejunal feeding tubes using erythromycin, air insufflation of the stomach and continuous ECG guidance.Design and setting Prospective study in a tertiary teaching hospital.Patients and participants 40 consecutive patients who required enteral nutrition and mechanical ventilation for at least 48 h.Interventions Erythromycin (200 mg) was administered intravenously 30 min prior to the insertion of the feeding tube. The post-pyloric feeding tube was then inserted into the stomach and 500 ml air insufflated. Stomach ECG was performed, and during further insertion of the tube the QRS complex was continuously monitored for a change in polarity, suggesting passage across the midline through the pylorus. At the end of the procedure aspirate was obtained from the feeding tube and checked for alkaline pH. Exact tube position was determined by abdominal radiography.Measurements and results In 88% of cases the feeding tubes were post-pyloric, with a median time to insertion of 15 min (range 7–75). No major complications were seen in 52 attempts. Change in QRS polarity had 94% sensitivity in predicting post-pyloric tip placement. Of the 32 alkaline pH aspirates 31 were post-pyloric.Conclusions This procedure is safe, effective and could be performed in a short time period within the confines of the intensive care unit without endoscopic assistance.     

Impact of blood sampling in very preterm infants

In a prospective investigation, 99 very preterm infants (gestational age (GA) 24-32 weeks, birthweight 560-2255 g) were studied during the first 4 weeks of life. The infants were divided into two groups: infants born extremely early (GA&lt;28 weeks, n=20) and infants of GA 28-32 weeks; the groups were then subdivided into critically ill or not. Diagnostic blood sampling and blood transfusion events were recorded. In total, 1905 blood samples (5253 analysis) were performed, corresponding to 0.7 samples (1.9 analysis) per day per infant. The highest frequencies were found during the first week, in infants with extremely low GA and in critically ill infants. The mean blood loss and transfusion volume values were 13.6 ml/kg and 6.3 ml/kg, respectively. In total, 19 infants (19%) received 34 transfusions corresponding to 0.3 transfusions per infant. Thirteen out of 20 infants of extremely low GA received 28 blood transfusions, corresponding to 27.0 ml/kg of blood on average during the study period. Four developed late anaemia; thus, in total, 14 (70%) of the infants born extremely early received 35 transfusions during the first 3 months of life, corresponding to a total mean of 34.8 ml/kg. For the extremely preterm infants a significant correlation between sampled and transfused blood volume was found (mean 37.1 and 33.3 ml/kg, respectively, r=+0.71, p=0.0003). The most frequently requested analyses were glucose, sodium and potassium. Few blood gas analyses were requested (1.9/infant). No blood losses attributable to excessive generous sampling were detected. The results show an acceptable low frequency of sampling and transfusion events for infants of GA 28-32 weeks. The study emphasizes the necessity of thorough reflection and monitoring of blood losses when ordering blood sampling in extremely preterm, critically ill infants.     

苏州地区儿童呼吸道合胞病毒感染的流行病学研究

目的 调查苏州地区儿童呼吸道合胞病毒（RSV）感染的流行现状及其影响因素,为RSV感染的防治提供依据.方法 收集苏州大学附属儿童医院2008年5月～2011 年4月三年间因呼吸道感染住院的患儿痰标本18,170例,采用直接免疫荧光法检测RSV抗原.结果 18,170例呼吸道感染患儿中,RSV阳性者2,773例,阳性检出率15.26%,82.87%的RSV感染发生在12月以下患儿;男女比例1.97：1（P＜0.001）,发病高峰集中在每年的12月至次年的3月;12月以内母乳喂养儿较非母乳喂养儿RSV阳性检出率低,年龄小于6月或在流行季节出生、被动吸烟、母亲吸烟、兄妹数量等均可增加RSV的感染率.结论 苏州地区儿童RSV感染的流行状况与国内和国外温带城市情况基本一致,冬春季为流行高峰,0～12月龄组的患儿RSV感染所占比例最大.母乳喂养具有保护作用,男性、被动吸烟、母亲吸烟、多兄弟姐妹、年龄小于6月或在流行季节出生等因素均增加患儿RSV感染风险.     

Behavioral responses to pain are heightened after clustered care in preterm infants born between 30 and 32 weeks gestational age

OBJECTIVE: To compare biobehavioral pain responses of preterm infants born at differing gestational ages (GAs) when pain was preceded by a rest period or by a series of routine nursing interventions. METHODS: In a randomized, within subjects, cross-over design, facial (Neonatal Facial Coding System), sleep/wake state and heart rate (HR) responses of 43 preterm infants [mean birth weight: 1303 g (range 590 g to 2345 g); mean GA at birth: 30 weeks (range 25 to 32)] were examined across 3 phases of blood collection (Baseline, Lance, and Recovery) under 2 conditions: pain after a 30-minute rest period versus pain after a series of routine nursing interventions (clustered care). Infant behavioral responses were coded from continuous bedside videotapes. HR was analyzed using custom physiologic signal processing software. RESULTS: Infants born at earlier GA (<30 wk) had equally intense facial responses during the Lance phase regardless of condition. However, later born infants (> or =30 wk GA) showed heightened facial responses indicative of sensitized responses during blood collection when it was preceded by clustered care (P=0.05). Moreover, later born infants had significantly lower facial (P=0.05) and HR (P=0.04) reactivity during Recovery when blood collection followed clustered care. DISCUSSION: Earlier born preterm infants showed heightened states of arousal and poor ability to modulate HR during Recovery when an invasive procedure was preceded by routine tactile nursing procedures. Alternatively, later born infants exhibited sensitized responses when clustered care preceded blood collection. Our findings support the importance of cue based individualized approaches to care.     

Neuromotor behavioural assessment of preterm infants at risk for impaired development

This study was undertaken to evaluate the effectiveness of a new neuromotor behavioural assessment in identifying preterm infants whose development was potentially at risk as a result of their early birth and immediate postnatal experiences. All infants born at less than 30 weeks gestation or who weighed less than 1000g at birth and cared for in the Mater Hospital's Neonatal Intensive Care Unit in Brisbane over a two year period were included in the study. Infants were assessed in their third week of life and again at 36 weeks gestational equivalent age, or prior to discharge, whichever occurred sooner. Results indicate that the assessment is effective in differentiating those infants who suffered from adverse neonatal events from those who did not, when assessed between 30 and 36 weeks gestational equivalent age. The assessment did not prove useful for infants of less than 30 or greater than 36 weeks gestational equivalent age.