Efficacy and tolerance of gastrostomy feeding in pediatric forms of neuromuscular diseases
Seguy, David
The neuromuscular diseases (NMD) comprise several entities characterized by a progressive muscular disorder. Recent advances in both orthopedic care and home noninvasive nocturnal ventilatory support have improved life expectancy. However, as in other chronic diseases, undernutrition is a common problem that often aggravates respiratory dysfunction and subsequent respiratory or systemic infections. Maintaining nutritional status is an important aim of medical teams managing these patients.
Gastrostomy feeding has become important for patients requiring long-term care. Since its first use in children in 1980 by Gauderer et al,1 percutaneous endoscopic gastrostomy (PEG) has been widely used in adults as well.2-5 It simplifies feeding patients and can be maintained in situ for long periods. However, there are only a few reports of its use in patients with NMD, and these were mainly focused on amyotrophic lateral sclerosis.6-9 The purpose of our study was to evaluate the nutritional effects and tolerance of gastrostomy feeding in a heterogeneous group of pediatric NMD patients.
CLINICAL RELEVANCY
PEG is well tolerated and results in an improvement of nutritional indices as long as enteral nutrition is continued in pediatric forms of neuromuscular diseases. The apparent benefit of gastrostomy feeding underlines the importance of an early multidisciplinary systematic management of these patients. This method allows for home-based enteral nutrition, even if its effect on prognosis and quality of life has still to be evaluated.
MATERIALS AND METHODS
Patient Population
Twelve patients had NMD among the 223 who underwent a gastrostomy placement between January 1990 and December 2000. Ten were male and 2 were female, ranging in age from 1 month to 25.5 years. They had clinical evidences of muscle wasting and weakness. Indications for gastrostomy placements were undernutrition (n = 10) or swallowing disorders (n = 8; Table I). All patients were followed in the pediatric department because their NMD had its onset early in life.
Data Collection
Nutritional indices and tolerance were retrospectively evaluated through routine clinical follow-up of patients. Lightly dressed patients were weighed on an electronic scale. As patients were recumbent and presented with frequent muscle retraction, we often assessed the sum of body segment length from the vertex to the feet in supine position as an estimate of height. Body weight and length were measured to the nearest 0.1 kg and 0.5 cm, respectively. Age and anthropometric measurements were recorded at birth, at the time of gastrostomy placement, after a 6-month and 1-year follow-up, and at the end of follow-up with gastrostomy feeding. The last one corresponded to the cut-off date (December 2000) if the enteral nutrition was continued at the time of the study (right censor), otherwise it was the date when enteral nutrition was stopped or the date of death. Because in some cases weight or height were not available exactly at the 6-month and 1-year follow-up because patient’s visit occurred sooner or later (never more than I month), the values were calculated from linear regression equations using the 2 closer points of the wanted exact date to homogenize the data. There were no missing anthropometric data for the other times (birth, gastrostomy placement, end of follow-up, or death). Complications that occurred during the gastrostomy feeding period were recorded.
Gastrostomy Placement
Fiber endoscopy (Olympus XP20 and Q30, Olympus Optical, C.O. Ltd, Tokyo, Japan) was performed under general anesthesia in 9 patients sedated with midazolam and using local anesthesia (1% lidocaine) in 2 patients (numbers 3 and 4), because of precarious respiratory status (vital capacities before placement were 400 and 540 mL, respectively). The pull-on-string technique of Gauderer et al was used in 11 patients. Antibiotic prophylaxis using amoxicillin-clavulanic acid (50 mg/kg) or cefotaxime (50 mg/kg) was administered 30 minutes before gastrostomy tube insertion. During endoscopic inspection of the esophagus, stomach, and duodenum and during the transillumination of the abdominal wall, which is necessary to rule out interposed organs, care was taken to minimize the insufflation of air. However, as the sheathed needle was inserted into the stomach percutaneously under endoscopic guidance, hyperinflation was maintained to displace neighboring organs downwards and laterally and allow apposition of the gastric and abdominal walls. Attention was made to finish the procedure by completely deflating the stomach. One patient (number 10), with a cervical esophagus stenosis induced by a compression of the pharynx posterior wall by vertebral prominence, required surgical gastrostomy because it was impossible to introduce the endoscope into the esophagus. Gastrostomy tubes (Corflo, Ansell Healthcare, Red Bank, NJ; Bard PEG, C. R. Bard, Inc, Murray Hill, NJ; Freka PEG, Fresenius Kabi, Bad Homburg, Germany; Petzer tube Proges, Le PlessisRobinson, France) 9-16 French in diameter were used. Eight were removable devices that could be removed after deflating the intragastric crown without the need for an endoscopy. In 2 cases, according to patient’s wishes, PEG were replaced by gastrostomy buttons (Mic-Key G, MIC, Ballard Medical Products, Draper, UT; Bard Button, C. R. Bard, Inc, Murray Hill, NJ), which were inserted at least 2 months after PEG placement to avoid dislocation of the stomach from the anterior abdominal wall.
Statistics
All results are expressed as means SEMs (range). Height-for-age (Z^sub H/A^), weight-for-age (Zw/A), and weightfor-height (Z^sub W/H^) z scores were calculated according to the method of Waterlow et al10 from means and SDs of height-for-age, weight-for-age, and weight-for-height charts for the French population (from birth to adulthood), respectively.11 Each patient was compared with him or herself, as the statistical significance of z scores changes after gastrostomy feeding placement was examined by a repeated-measures analysis of variance. The level of statistical significance was set at p
RESULTS
Demographics
Clinical characteristics, times of follow-up, and the weight gains at the last date with enteral nutrition by gastrostomy feeding are represented in Table I for each patient. The mean duration of feeding by gastrostomy was 2.5 years 8 months (range, 2.5 months to 7 years) in the whole group and 3 years 8 months (range, 1 to 7 years) for the 10 patients who had more than 1-year follow-up. At the cut-off date in December 2000, 5 patients were right censored because they were continuing enteral nutrition, 4 had stopped, and 3 had died. In muscular dystrophy patients (n = 5), the mean age of NMD diagnosis was 5 +/= 1 years (birth to 9 years) and the mean age of the time of gastrostomy placement was 16.5 +/= 2 years (range, 8.5 to 25.5 years). For other NMD patients (n = 7), these values were 1.5 years +/= 8 months (birth to 6 years) and 3.5 +/= 1.5 years (1 month to 14 years), respectively.
Nutritional Indices
The z scores were normal at birth in all subjects (n = 12). Significant improvement in weight-for-age (p
Tolerance
There was no respiratory failure requiring mechanical ventilation or tracheotomy consequent to the general anesthesia used for gastrostomy placement. Several local complications occurred at the site of gastrostomy. These included abdominal wall abscesses, skin ulceration, external granulation, and intragastric pseudopolyp, each seen in a single patient; peristomal redness in 2 patients; and perigastrostomy leaks secondary to equipment failure in 6 patients. All the complications resolved within several days after local treatment (antibiotics, silver nitrate application) or change of the gastrostomy devices.
Five patients presented with gastroesophageal reflux (GER) as a complication of their NMD before gastrostomy placement. Two had minor episodes of hematemesis related to their esophagitis, confirmed at endoscopy. Three patients (numbers 8, 9, and 11) had persistent GER after gastrostomy placement. Despite prokinetic and antisecretory drugs, they each developed at least 1 episode of pneumonia. Two of these patients (numbers 8 and 9) died from respiratory insufficiency 10 weeks after PEG placement, at the age of 6 months and 3 years, respectively. A third patient (number 1) died when he was 21 years old, after a 14-month follow-up, because of the progression of his MND. No other major complication of gastrostomy was encountered during the study period.
DISCUSSION
We studied changes in the nutritional indices in a heterogeneous group of 12 NMD patients after gastrostomy placement, which was a PEG in 11 cases. This study reflects our experience of undernutrition in pediatric-onset NMD representing a wide variety of rare diseases. From gastrostomy placement to the end of follow-up (n = 12), an improvement of both weight-forage and weight-for-height z scores was observed for all the patients. Our results show that gastrostomy feeding is a simple and reliable technique in most NMD patients when nutrition support is needed. Nevertheless, when patients have severe congenital myopathy, severe GER, or severe respiratory deficiency that requires intensive care, or when patients have a poor short-term prognosis with a high risk of death, it is difficult to know if gastrostomy feeding is still indicated. This was the case for 2 of our patients who were followed for 1 year of follow-up experienced a decrease in their nutritional indices and decided to recommence enteral nutrition. This strongly supports the efficacy of gastrostomy feeding in these patients. Because most of the NMD patients had a severe reduction in muscle mass, we cannot state that weight should normalize after renutrition, based on charts for non-NMD patients. It has been shown that so-called “normal” weight in patients with Duchenne muscular dystrophy (DMD) who have disorders and increased muscle wasting reflect severe obesity. 12 Thus, the aim of gastrostomy feeding was not to “normalize” weight in our patients but to improve it, according to the reference data available for DMD,13 or with general well-being in the other patients. Although not specifically assessed in this study, gastrostomy placement was associated with an improved well-being of patients, who all reported a decrease of the time dedicated to eating. The effects on quality of life in these patients also have to be considered, but it was impossible to investigate this aspect in our retrospective study. There are a few published reports that document an improved quality of life after gastrostomy feeding in patients with severe neurologic diseases when feeding problems occur. 14
Evaluation of malnutrition is difficult in NMD patients. Conventional methods (ie, anthropometric charts, bioelectric impedancemetry, or absorptiometry) are not validated in NMD because of heterogeneity of muscular involvement, age differences, wide range of prognosis, and severity of diseases. Except for DMD, for which standard weight-for-age charts have been established, there are no specific published tools.13 For these reasons, we compared patients with themselves using anthropometry. Height measurement was very difficult in NMD patients, and we often had to use segment lengths from vertex to feet. Whatever the method used for height assessment in such patients, the risk of error is significant, so that nutritional indices derived from height or length should be interpreted cautiously. Moreover, weight is not perfect for assessing nutritional efficacy of gastrostomy feeding; however, it was available for all our patients from birth to adulthood. Because the group was very heterogeneous in both age and form of NMD and because we have followed up several of these patients from birth to adulthood, we used z scores to normalize the nutritional indices and to allow comparison of each patient with him or herself during their follow-up. Calculation of z scores for height and weight was possible from birth to adulthood using the charts of Sempe et al for the French population. Therefore, the use of these anthropometric-derived indices could not reflect the overall nutritional status of our patients, but at the present time, there is no validated nutritional method assessment available in neuromuscular disorders. Despite these methodological limitations, we believe that all 12 patients had severe undernutrition and feeding problems before gastrostomy feeding started.
There are a few studies on enteral nutrition in patients with NMD. Four of them were performed in adults with amyotrophic lateral sclerosis and documented the benefits in nutritional status and life expectancy.6-9 Birnkrant et al 15 reported their experience with PEG in 4 children with type I spinal muscular atrophy (Werdnig-Hoffmann disease). To the best of our knowledge, there is no adult series that includes other forms of NMD, nor any large pediatric series concerning efficacy and tolerance of enteral nutrition with a long follow-up. Our series showed a wide range of age at gastrostomy placement (1 month to 25.5 years) in NMD patients with disease onset early in life; this explains why there was no case of amyotrophic lateral sclerosis, because the juvenile form is very rare.
Because of precarious respiratory status, PEG is more convenient than surgical gastrostomy in NMD, and some measures seem able to compensate the muscular and respiratory weakness of these patients during insertion. However, PEG placement in this population of patients is not risk-free because of the possibility of respiratory failure during or immediately after the procedure, and the best method of respiratory support is still not known. A novel use of noninvasive positive pressure ventilation to provide respiratory support during sedation for percutaneous placement has been described for patients with NMD.15,16 The primary risk associated with this technique is the lack of definitive airway protection during the procedure, which must be balanced against the risks of intubation in an anesthetized patient with neuromuscular disease.16 This method also seemed useful to facilitate extubation in patients with NMD who had undergone gastrostomy placement while intubated.17 Noninvasive ventilation was not used in this study, but the insertion technique was adapted to facilitate the early removal of gastric air.7 In recent years, improvements in gastrostomy feeding devices have simplified management. In particular, in some cases, we used a PEG device that can be removed without endoscopy and a gastrostomy button that can be inserted without anesthesia, which constituted a safe and esthetic solution for our patients.18 When we removed the PEG tube, we never cut the end because of the risk of digestive obstruction; instead, we used removal devices or undertook a new endoscopy.
A high percentage of GER (36%) occurred in the patients we studied. Others have also found this in NMD patients.15,19 In our study, 2 patients, who had severe respiratory problems and who died, had uncontrolled GER. Many factors could contribute to the worsening or occurrence of GER after gastrostomy placement: previous GER, underlying disease, type and location of the gastrostomy tube, or type of feeding (bolus versus continuous). Surgical gastrostomy is reported to worsen GER.20-23 A few contradictory data exist in the literature about the relationship between PEG and GER in children. Sulaeman et a124, 25 and our study have previously shown that, in children, GER does not worsen after PEG, but these results conflict with the studies of others.26,27 However, when severe GER associated with impaired pulmonary function is present before gastrostomy feeding is decided, an alternative to PEG should be discussed, such as gastrostomy associated with fundoplication or with esophagogastric dissociation proposed by Bianchi.28,29 In this study, the possibility that PEG may have increased GER and contributed to the death of 2 patients cannot be excluded. The risk of increasing GER must be considered in these patients when evaluating them for PEG placement.
Indications for nutrition support by gastrostomy in our study were undernutrition (82%) and swallowing disorder (73%), which was present from birth in 2 patients. A swallowing disorder, often ignored, can further aggravate undernutrition and respiratory failure. In DMD, histologic study of the distal esophagus, stomach, small bowel, and colon has shown edema, atrophy, and fibrosis of smooth muscles.30,31 More than one half of the patients with muscular dystrophy had dysphagia, regurgitation, epigastralgia, and asymmetric contractions of the pharynx. Moreover, esophageal symptoms can predominate even when muscular signs are missing. They are related to an atrophy of pharyngeal and esophageal striated muscles.32 In addition to swallowing disorders, NMD patients have to labor with motor disorders that preclude the possibility of selffeeding. Consequently, before gastrostomy feeding, techniques and orthopedic supports have to be proposed for these patients, such as adjusted place settings and tableware, neck collars, attractive textureadapted meals, and improvement of mastication by orthodontic techniques.33
Nutrition management of our patients was adapted to their age and to the evolution of their disease. All patients received nocturnal cyclic nutrition, using a polymeric lactose-free diet. Feeding intolerance was not present in our population except for constipation in 4 patients, which was always cured either by fiberenriched diet or laxatives. It was difficult to evaluate their energy requirements because we did not measure resting energy expenditure by indirect calorimetry. In these patients, resting energy expenditure is practically equal to total energy expenditure because of amyotrophy and reduced physical activity.34 Energy requirements were deduced from physicians’ experience, food questionnaires, and follow-up (estimating weight gain and well-being).
Except for patients affected by serious GER, gastrostomy feeding is well tolerated by NMD patients and is well suited for long-term treatment at home, after appropriate training. In this group of patients, gastrostomy feeding was not associated with more long-term complications than in other pediatric diseases.35 Gastrostomy feeding permits an improvement of nutritional indices as long as enteral nutrition is continued. Therefore, the potential benefit of gastrostomy feeding in these patients, including decreased risk of aspiration and improvement of nutritional status and quality of life, have to be weighed against the risks of gastrostomy placement by each patient and their family. Our study underscores the importance of an early multidisciplinary systematic management of these patients. Therefore, due to methodological limitations of our study, prospective controlled studies that measure a variety of nutritional indices are needed to establish the efficacy of gastrostomy feeding in pediatric forms of neuromuscular diseases and its consequences on prognosis, respiratory function, and quality of life.
Copyright American Society for Parenteral and Enteral Nutrition Sep/Oct 2002
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