Limitations and drawbacks of 'fine bore' nasogastric feeding tubes

The clinical use of unweighted nasogastric feeding tubes (n = 491) was compared with that of weighted nasogastric feeding tubes. No advantage was found in the use of the weighted tubes.     

7 g weighted versus unweighted polyurethane nasoenteral tubes--spontaneous transpyloric passage and clinical performance: a controlled randomised trial

A proportion of patients requiring enteral nutrition is at increased risk of regurgitation or pulmonary aspiration of enteral diet as a result of gastric atony or paresis. The positioning of the distal end of an enteral feeding tube beyond the pylorus into duodenum or jejunum may reduce this risk. It has been postulated that by suitable lengthening of feeding tubes and by altering the distal end tip profile or by the addition of a weight, spontaneous passage of a tube through the pylorus after pernasal insertion may be achieved. In a recent controlled trial we were unable to demonstrate any advantage to a) modifying the tip profile or b) the addition of a 2.4 g weight. This prospective controlled clinical study examined the difference between an unweighted polyurethane tube which had performed optimally in the previous study and a new 7 g weighted tube similar in all other respects. In both cases less than 50% of tubes had passed spontaneously through the pylorus when assessed at 24 h, with no significant difference in performance (p = 0.38). When comparing overall length of time that each tube remained in situ, there was similarly no significant difference between the 7 g weighted and unweighted tubes (p = 0.277). We conclude that the addition of a 7 g weight to a suitably lengthened enteral feeding tube confers no advantage on either incidence of spontaneous transpyloric passage or in prolonging tube usage. If post-pyloric feeding is indicated for a patient, positioning by either fluoroscopic or endoscopic techniques should be undertaken.     

Spontaneous transpyloric migration of a ballooned nasojejunal tube: a randomized controlled trial

BACKGROUND: Spontaneous transpyloric migration of a simple nasojejunal tube (NJT) can be expected in only one-third of insertions. Guidance of the tube by radiologic or endoscopic maneuvers is usually required. We believed that locating a 5-mL balloon near the tip of an NJT on which natural peristalsis could act would improve the rate of spontaneous transpyloric migration and facilitate small bowel propagation. METHODS: Thirty healthy volunteers were randomly assigned to have an inflated or noninflated, ballooned NJT fashioned from a modified 9F Hickman line catheter inserted. The pH of aspirates was measured hourly and the final location of the tube assessed by gastrografin contrast abdominal x-ray (AXR) at the end of 6 hours, at which time the tube was removed. RESULTS: After 6 hours, spontaneous transpyloric migration occurred in 86.6% of the ballooned and 66.6% of the nonballooned tubes. The final disposition of the ballooned tubes was: stomach, 2 (13.3%); duodenum, 1 (6.7%); and small bowel, 12 (80%). The final disposition of the nonballooned tubes was: stomach, 5 (33%), NS; duodenum, 9 (60%), p < .05; and small bowel, 1 (6.7%), p < .05. CONCLUSIONS: Ballooned NJT have a higher rate of spontaneous transpyloric migration and are significantly more likely to achieve an optimal small bowel location.     

Continuation of transpyloric feeding during weaning of mechanical ventilation and tracheal extubation in children: a randomized controlled trial

BACKGROUND: Nutrition support is essential in the management of critically ill children. There is no current literature to support the common practice of discontinuing enteral nutrition delivered through a transpyloric feeding tube during the tracheal extubation process. We conducted a prospective, randomized controlled trial in mechanically ventilated children to examine the safety and efficacy of continuous transpyloric feeding compared with interrupted transpyloric feeding at the time of tracheal extubation. METHODS: Subjects were randomly assigned to receive transpyloric feeding throughout the tracheal extubation process (Continuous Group) or to have transpyloric feeding discontinued 4 hours before tracheal extubation and restarted 4 hours after tracheal extubation (Interrupted Group). Data consisting of patient demographics, admission pediatric risk of mortality (PRISM) score, diagnoses, adverse events (feeding intolerance, gastroesophageal reflux, and pulmonary aspiration), daily feeding volume, and caloric intake were recorded for the 3 days surrounding tracheal extubation. RESULTS: Fifty-nine patients completed the study (29 in Continuous Group, 30 in Interrupted Group). There was no episode of pulmonary aspiration in either group. The Continuous Group experienced 4 adverse events, whereas the Interrupted Group experienced 3 adverse events (p = not significant). The Continuous Group received 92 +/- 2.5% of their caloric goal on the day of weaning from the ventilator (day 1) and 93 +/- 3.2% on the day of tracheal extubation (day 2) compared with 76 +/- 4.2% and 43 +/- 4.3%, respectively, in the Interrupted Group (p < .004 and p < .0001, respectively). CONCLUSIONS: Continuous transpyloric feeding during weaning from the ventilator and tracheal extubation is safe and results in the delivery of more optimal nutrition.     

Evaluation of the efficacy of a polyurethane condom: results from a randomized, controlled clinical trial

CONTEXT: Condoms made of latex are not comfortable or appropriate for all consumers. Polyurethane condoms may provide a needed alternative. METHODS: In a double-masked study, 805 monogamous couples were randomized to use either the polyurethane condom or the latex condom for six months. Couples recorded the frequency of intercourse, of condom use and of breakage and slippage throughout the trial in coital diaries and in detailed reports on the first five uses. Breakage and slippage rates were determined, and typical-use and consistent-use pregnancy rates were calculated using life-table analysis, adjusted for use of emergency contraception. RESULTS: The six-month pregnancy rate during typical use (adjusted for use of emergency contraception) was 4.8% for the polyurethane condom and 6.3% for the latex condom. Similarly adjusted pregnancy rates during consistent use over six completed menstrual cycles--2.4% for the polyurethane condom and 1.1% for the latex condom--did not differ significantly. Clinical failure rates (including breakage and slippage occurring during either intercourse or withdrawal) were 8.5% for the polyurethane condom and 1.6% for the latex condom. In general, male participants were more satisfied with the latex condom, and users of latex were significantly less likely to drop out of the study for condom-related reasons than were users of polyurethane. CONCLUSIONS: Although polyurethane and latex condoms provide equivalent levels of contraceptive protection, the polyurethane condom's higher frequency of breakage and slippage suggests that this condom may confer less protection from sexually transmitted infections than does the latex condom.     

Estimation of energy requirements in a controlled feeding trial

BACKGROUND: Estimating energy requirements is a frequent task in clinical studies. OBJECTIVE: We examined weight patterns of participants enrolled in a clinical trial and evaluated factors that may affect weight stabilization. The Harris-Benedict equation and the FAO/WHO equation, used in conjunction with physical activity levels estimated with the 7-d Physical Activity Recall, were compared for estimating energy expenditure. DESIGN: This was a multicenter, randomized controlled feeding trial with participants of the Dietary Approaches to Stop Hypertension Trial. For 11 wk, the amount of food participants received was adjusted to maintain their body weights as close to their initial weights as possible. Change-point regression techniques were used to identify weight-stable periods. Factors related to achieving weight stabilization were examined with logistic regression. RESULTS: A stable weight was achieved by 86% of the 448 participants during the run-in period and by 78% during the intervention period. Energy intake averaged 11 +/- 2.4 MJ/d (2628 +/- 578 kcal/d), with most participants (n = 270) requiring 9-13 MJ/d (2100-3100 kcal/d). The difference between predicted and observed intakes was highest at high estimated energy intakes, mainly because of high and probably incorrect estimates of the activity factor. Participants with lower energy intakes tended to need less adjustment of their energy intakes to maintain a stable weight than did participants with higher energy intakes. CONCLUSIONS: Weight stabilization is not affected by diet composition, sex, race, age, or baseline weight. Either the Harris-Benedict equation or the FAO/WHO equation can be used to estimate energy needs. Activity factors > 1.7 often lead to overestimation of energy needs.     

Teaching clinical epidemiology: a controlled trial of two methods

The teaching of clinical epidemiology to second-year students at the Bowman Gray School of Medicine is carried out using journal articles to illustrate concepts. Because of the need for discussion, the instructors believed that the concepts of epidemiology might best be learned by, and that greater satisfaction with the learning process might be derived from, small group discussions rather than large lecture sessions. To test these hypotheses, students were randomized into either one of two discussion groups or a larger lecture group. The course handouts and text were identical, and the three instructors presented the same material successively to each group. In the final examination, all three groups answered approximately 26 of 36 questions correctly. Seventy percent of students responded to a questionnaire at the end of the course. There were no significant differences between the discussion and lecture groups in their ability to read and understand medical articles. However, the discussion group students were more favorable in their assessment of the success of the teaching method and in their perception of the importance and overall quality of the course. While there may be little difference in the short-term retention of epidemiological principles between the two teaching methods, the greater satisfaction reported by the students in the small groups will stimulate us to try to provide that type of learning environment in the future.     

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.     

Prevention of childhood household injuries: a controlled clinical trial.

Injuries claim the lives of more children each year than the next six leading pediatric disorders combined, and produce injuries that require medical attention for one in three children. In the preschool age group, 91 per cent of these accidents and over one-half the resultant fatalities occur in the home. This paper reports the results of a controlled clinical trial conducted to evaluate the implementation of a health education program intended to reduce the risk of childhood household injuries. The study population was randomly assigned into two demographically comparable groups. Only the experimental group mothers received an educational intervention consisting of a tutorial, home safety-proofing assignments, and follow-up. The homes of the two groups were later assessed for hazards during an unannounced visit by an interviewer who did not know to which group each home belonged. A home safety score mean for the two groups was almost identical. The program stimulated heightened interest and stated intent to improve, but did not result in actual reduction of household hazards. Active health education, as used and evaluated in this study, appears to have limited effectiveness when applied to home safety. Approaches such as "passive" measures may offer greater potential for household injury reduction.     

Improving physicians' and nurses' clinical breast examination: a randomized controlled trial

Health professionals' clinical breast examination accuracy and skills are not optimal. We conducted a randomized trial to evaluate changes in physicians' and nurses' lump detection accuracy and examination skills after a training program emphasizing development of tactile skills and using silicone breast models containing lumps of varying sizes, degrees of hardness, and depth of placement. Sensitivity, specificity, and examination technique were measured before and four months after training in 43 experimental group and 46 control group participants. Mean sensitivity increased from 57% to 63% in the experimental group but decreased from 57% to 56% in the control group (P less than or equal to .05). The experimental group's posttest sensitivity was better for each lump characteristic, with statistically significant improvement for the very small (0.3 cm) and medium hard lumps. Duration of examination independently predicted sensitivity. Specificity decreased from 56% to 41% in the experimental group while it increased from 56% to 68% in the control group (P less than or equal to .05). Physicians had significantly higher mean sensitivity than nurses overall, as well as for the larger (1.0 cm), very small (0.3 cm), and softer lumps, but significantly lower mean specificity (33% versus 57%, P = .03). The experimental group improved significantly in five of six technique components while the control group improved in only one. To determine the effect of training on specificity in the clinical setting, we examined medical records of women seen by a subset of experimental and control physicians during the six months following training. There were no significant differences in the proportion of abnormal breast examinations reported or the number of mammograms ordered by experimental and control physicians. Our results show health professionals can be taught successfully to improve their clinical breast examination accuracy and skills.     

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.     

Design and performance of a multicentre,randomized controlled trial of teleconsulting

We have designed and performed a multicentre, randomized controlled trial of teleconsulting. The trial investigated the effectiveness and cost implications in rural and inner-city settings of using videoconferencing as an alternative to general practitioner referral to a hospital specialist. The participating general practitioners referred a total of 3170 patients who satisfied the entry criteria. Of these, 1040 (33%) failed to provide consent or otherwise refused to participate in the trial. Of the patients recruited to the trial, a total of 1902 (91%) completed and returned the baseline questionnaire. Although the trial was successful in recruiting sufficient patients and in obtaining high questionnaire response rates, the findings will require careful interpretation to take account of the limits which the protocol placed on the ability of general practitioners to select patients for referral.     

Bedside placement of nasojejunal tubes: a randomised-controlled trial of spiral- vs straight-ended tubes

BACKGROUND AND AIMS: The success rate of unguided nasojejunal feeding tube insertion is low, thus often requiring endoscopic or radiological assistance. The spiral end of the Bengmark nasojejunal tube is supposed to aid post-pyloric placement, but no comparative trial has been performed. METHODS: Patients requiring nasojejunal feeding were randomised to have either Medicina (straight) or Bengmark (spiral) nasojejunal tube placed after stratification into those with normal gastric emptying or clinical evidence of delayed gastric emptying. Nasojejunal tubes were placed at the bedside in a standard fashion without radiological guidance by the same person for pre- and/or post-operative feeding. Bolus intravenous metaclopromide (10mg) was given prior to insertion in the abnormal gastric emptying group. Abdominal radiographs were obtained at 4 and 24h, and the primary end-point was jejunal placement at 24h. RESULTS: Forty-seven patients were randomised of which 17 (11 straight, 6 spiral) could not tolerate the nasojejunal tube. Of the 30 remaining patients, 16 had normal gastric emptying. In patients with normal gastric emptying, successful placement at 24h was achieved in 78% (spiral tube), vs 14% (straight tube) (P=0.041). In the abnormal gastric emptying group, success rates were 57% and 0%, respectively (P=0.07). CONCLUSION: Spiral nasojejunal tubes are preferable to straight tubes for bedside unguided post-pyloric feeding in patients with normal gastric emptying.     

Early versus late enteral feeding of mechanically ventilated patients: results of a clinical trial

BACKGROUND: This study sought to compare 2 strategies for the administration of enteral feeding to mechanically ventilated medical patients. METHODS: The prospective, controlled, clinical trial was carried out in a medical intensive care unit (19 beds) in a university-affiliated, urban teaching hospital. Between May 1999 and December 2000, 150 patients were enrolled. Patients were scheduled to receive their estimated total daily enteral nutritional requirements on either day 1 (early-feeding group) or day 5 (late-feeding group) of mechanical ventilation. Patients in the late-feeding group were also scheduled to receive 20% of their estimated daily enteral nutritional requirements during the first 4 days of mechanical ventilation. RESULTS: Seventy-five (50%) consecutive eligible patients were entered into the early-feeding group and 75 (50%) patients were enrolled in the late-feeding group. During the 5 five days of mechanical ventilation, the total intake of calories (2370 +/- 2000 kcal versus 629 +/- 575 kcal; p < .001) and protein (93.6 +/- 77.2 g versus 26.7 +/- 26.6 g; p < .001) were statistically greater for patients in the early-feeding group. Patients in the early-feeding group had statistically greater incidences of ventilator-associated pneumonia (49.3% versus 30.7%; p = .020) and diarrhea associated with Clostridium difficile infection (13.3% versus 4.0%; p = .042). The early-feeding group also had statistically longer intensive care unit (13.6 +/- 14.2 days versus 9.8 +/- 7.4 days; p = .043) and hospital lengths of stay (22.9 +/- 19.7 days versus 16.7 +/- 12.5 days; p = .023) compared with patients in the late-feeding group. No statistical difference in hospital mortality was observed between patients in the early-feeding and late-feeding groups (20.0% versus 26.7%; p = .334). CONCLUSIONS: The administration of more aggressive early enteral nutrition to mechanically ventilated medical patients is associated with greater infectious complications and prolonged lengths of stay in the hospital. Clinicians must balance the potential for complications resulting from early enteral feeding with the expected benefits of such therapy.     

Effects of fish oil on serum lipids in men during a controlled feeding trial

Effects of fish-oil (FO) feeding on serum lipids were investigated in a 42-d controlled diet study. Fifteen healthy male college students were assigned to one of three groups: control (0 g FO); 5 g FO, supplying 2 g n - 3 (omega-3) fatty acids (FAs); or 20 g FO, supplying 8 g n - 3 FAs. In an initial 7-d period subjects consumed a basal diet with no FO. Then FO replaced an equivalent amount of margarine for 5 wk. FO feeding significantly (p less than 0.05) decreased the serum n - 6 FAs, linoleic acid, eicosatrienoic acid, and arachidonic acid. A significant increase in the n - 3 FAs, eicosapentaenoic acid and docosahexaenoic acid, was noted in serum, platelet, and neutrophil phospholipids. The 20-g-FO group showed a 30% decrease (p less than 0.01) in triglycerides after 2 wk FO with no further decrease observed. Thus, 20 g FO produced changes in both FA patterns and triglyceride concentrations whereas 5 g FO produced changes in FA patterns only. Neither FO amount resulted in significant changes in total or HDL cholesterol, apolipoprotein A-I, or apolipoprotein B-100.     

Use of small-bore feeding tubes: successes and failures

PURPOSE OF REVIEW: Early enteral nutrition is the preferred option for feeding patients who cannot meet their nutrient requirements orally. This article reviews complications associated with small-bore feeding tube insertion and potential methods to promote safe gastric or postpyloric placement. We review the available bedside methods to check the position of the feeding tube and identify inadvertent misplacements. RECENT FINDINGS: Airway misplacement rates of small feeding tubes are considerable. Bedside methods (auscultation, pH, aspirate appearance, air bubbling, external length of the tube, etc.) to confirm the position of a newly inserted small-bore feeding tube have limited scientific basis. Radiographic confirmation therefore continues to be the most accurate method to ascertain tube position. Fluoroscopic and endoscopic methods are reliable but costly and are not available in many hospitals. Rigid protocols to place feeding tubes along with new emerging technology such as CO2 colorimetric paper and tubes coupled with signaling devices are promising candidates to substitute for the blind placement method. SUMMARY: The risk of misplacement with blind bedside methods for small-bore feeding tube insertion requires a change in hospital protocols.     

Statistical analysis of cost outcomes in a randomized controlled clinical trial

This paper suggests an approach to deal with an estimation problem which is often encountered in analyzing the longitudinal cost data gathered in a clinical trial. The source of that estimation problem is twofold: 1) a considerable number of missing data due to treatment-related withdrawal of severely affected patients with high health care costs in only one the treatment groups and 2) a heavily skewed cost distribution due to rare high-cost events. The approach is illustrated using data from a trial comparing 3 different drug regimes. In order to calculate costs per patient-year in case of selectively missing data we extrapolated the costs of patients with incomplete follow-up. Due to the skewness and the associated large variance in costs per patient-year, these costs cannot be analyzed using common parametric statistical methods relying on underlying normal distributions. A logarithmic transformation was performed to approximate a normal distribution, reduce the impact of extreme values and create similar size variances in the treatment groups. An ordinary least squares regression analysis of transformed data then standardized for differences in patient characteristics between the groups. For the retransformation, the so-called smearing estimate was used. This ‘transformation-standardization-retransformation’ approach enabled us to provide more consistent and efficient estimates of cost differences that were shown to be statistically significant and judged to be important.