Percutaneous endoscopic gastrostomy versus nasogastric tube feeding for adults with swallowing disturbances
Abstract
This is a protocol for a Cochrane Review (Intervention). The objectives are as follows:
To evaluate the effectiveness and safety of PEG as compared to a nasogastric tube for nutrition in adults with swallowing disturbances.
Background
A number of conditions compromise the transport of food along the digestive tract. Disturbances may be due to blockage, as seen in stenosis and cancer of the stomach or larynx, or due to swallowing difficulties such as in stroke sequelae, cranial encephalic trauma, brain tumours, and amyotrophic lateral sclerosis (Löser 2005). Several approaches are available to provide nutritional support. Nasogastric tube feeding is a classic, time‐proven technique, although its prolonged use can lead to complications such as lesions to the nasal wing, chronic sinusitis, gastro‐oesophageal reflux, and aspirative pneumonia (Bastow 1986). Two meta‐analyses comparing tube placement into the stomach or duodenum revealed no significant difference between the methods in terms of length of hospital stay, mortality, or complications (Marik 2003; Ho 2006). In addition to complications, the need to change the tube due to blockage inherent to its narrow gauge coupled with its disagreeable appearance in social settings have led to the election of alternative techniques whenever possible.
Gastrostomy has been used to gain access to the stomach for long‐term enteral feeding in patients with swallowing limitations who require nutritional support. The main criteria for indicating gastrostomy are (i) a reasonable prospect of patient survival and (ii) normal intestinal function. This surgical procedure was first carried out successfully in humans in 1876, by Verneuil in France. Following various modifications, Stamm devised the technique most frequently used to this day (Ljungdahl 2006). In 1980, Gauderer et al described a new technique of feeding tube placement in gastrostomy using endoscopy, called percutaneous endoscopic gastrostomy (PEG). This involves a local anaesthetic and does not require laparotomy (Gauderer 1980). Since the introduction of PEG, a number of studies comparing methods of gastrostomy have been conducted. A prospective, randomised, controlled trial conducted by Ljungdahl et al (Ljungdahl 2006) found a lower mean procedure time and complication rate for PEG (42.9% versus 74.3%, P < 0.01). No significant difference was observed regarding mortality. Recently published guidelines on enteral nutrition recommend the performing of gastrostomy, preferably endoscopically (Löser 2005).
Previous systematic reviews and meta‐analyses on enteral nutrition approaches have been performed, but not with the broad scope we propose. Langmore et al (2007) published a meta‐analysis that investigated enteral nutrition, specifically in amyotrophic lateral sclerosis, comparing the use of several types of feeding tubes in patients being fed orally (Langmore 2007). However, they did not find any controlled or randomised studies. Another meta‐analysis compared nutrition by endoscopic gastrostomy and nasogastric tube including only post‐stroke patients (Bath 1999). Thereafter a number of controlled and randomised studies were published that compared the two methods of nutritional support in stroke patients and those admitted to intensive care units with a range of different pathologies, as well as individuals on mechanical ventilation (Dennis 2005; McClave 2005; Douzinas 2006; Hamidon 2006).
Assessment of these latest studies in patients with a range of pathologies, together with analysis of the optimal point to commence nutritional support, warrant mapping by means of a systematic review so as to offer the best evidence available on which to base decisions.
Description of the condition
Malnutrition is a prevalent, undesired condition affecting up to 40% of hospitalised patients. It has important causal associations with morbidity and mortality. Low nutritional status may affect recovery from illness, surgery, and injury. A body mass index (BMI) of less than 20 kg/m2 suggests undernutrition. Mortality rates tend to be higher in elderly people in comparison to other subgroups of hospitalised patients and in those with a BMI of less than 18 kg/m2. Malnutrition may manifest as impaired cardiac function and weak muscles (including respiratory muscles), with consequent higher risk of thromboembolism, chest infection, and pressure sores (Pearce 2002). Swallowing disturbances usually cause malnutrition and are common after an acute stroke (in 29% to 64%). Clinical diagnosis of swallowing disturbances can be given based on clinical signals such as excessive secretions; excessive tongue movement; pocketing of food in the cheek, under the tongue or on the hard palate; or coughing or choking while eating. Although not usually used in daily practice, radiological tests like videofluoroscopic modified barium swallow and a videofluoroscopic swallowing study can be used for diagnosis (Finestone 2003).
Patients with indications for enteral nutrition include those with conditions associated with swallowing disorders, such as motor neurone disease and multiple sclerosis; physical obstruction to swallowing, such as oesophageal tumours; an inability to ingest food due to head injury or stroke; and those with anorexia due to an underlying disease such as chronic lung disease, irritable bowel disease, or cancer. Dysphagic patients and those with anorexia, malabsorption, or excessive catabolism also may need long‐term enteral feeding (Pearce 2002). Enteral nutrition can be provided in the form of drink supplements or, if a patient is unable to take adequate nutritional supplements orally, fed via an enteral tube into the stomach or small bowel (Löser 2005).
Description of the intervention
In general, tube systems for artificial enteral nutrition can be positioned by nasal insertion, guided percutaneous application, or surgical techniques. The superiority of percutaneously placed gastrostomies compared to the former surgical gastrostomy procedures (that is Witzel, Stamm, Janeway techniques) has been shown clearly in many clinical studies (Löser 2005). Lower complication rates, reduced hospital length of stay and costs have been reported (Grant 1988; Ljungdahl 2006). Most patients who require nutritional support need it for at least one month, with the nasogastric sound probe being the main way of infusion. The probe used is made of thin polyurethane, size 14 with an internal diameter of 3.3 mm, and is inserted by a trained professional in order to prevent complications such as perforation and tracheobronchial location (Löser 2005; Hamidon 2006). Another method of infusion, percutaneous endoscopy gastrostomy (PEG), is generally used when there is a need for enteral nutrition for a longer time period (Pearce 2002; Löser 2005). This procedure can be done by either 'pull' or 'push' techniques, the former being simpler and more frequently used. Both techniques use a silicon probe (for example 24 Fr, internal diameter 5.5 mm). The puncture site is marked with gastroscopic monitoring of the anterior gastric wall in the region of the distal corpus, after adequate local anaesthesia and intravenous sedation (Löser 2005; Hamidon 2006). Prospective studies have shown that the early insertion of the probe via PEG improves the patient’s nutritional state (Norton 1996; Hamidon 2006). Patients treated for head and neck carcinoma have considered PEG to be more acceptable than a nasogastric tube (NGT) even though dysphagia is more prevalent (Mekhail 2001). A cohort study verified the acceptability of PEG, with significantly higher survival time and lower aspiration rates (Dwolatzky 2001) compared to NGT. On the other hand, a narrative review (Plonk Jr 2005) reported increased risk of death in stroke patients with PEG compared to NGT and concluded that aspiration pneumonia rates were similar.
Radiologically placed gastrostomy (RIGs) is another method of enteral nutrition, but operationally different from percutaneous endoscopic gastrostomy (PEG). RIG is not an endoscopic procedure and utilises fluoroscopy, performed in an interventional radiologic suite (Barkmeier 1998; Chiò 2004).
How the intervention might work
The percutaneous gastronomy probe is of a larger calibre compared to an NGT and is placed in the abdomen. This leads to less interruption of nutrition by the withdrawal of the probe as well as reduced reflux with consequent aspiration, thus being less embarrassing for the patient (Dwolatzky 2001; Pearce 2002). Patients and carers believe that nutrition via PEG helps in feeding and the ability to cope, being more convenient than NGT (Anis 2006). PEG‐related morbidity and mortality are 9.4% and 0.53%, respectively. There are, however, exclusive complications for endoscopy percutaneous gastrostomy, such as peritonitis, buried bumper syndrome, gastrocolocutaneous fistula, and wound infection (Potack 2008). Complications of NGT due to its nasogastric insertion and positioning are also cited, including sinusitis, laryngeal ulcerations, pneumothorax, and tracheoesophagic fistula; the latter due to incorrect positioning of the tube (Pearce 2002).
Why it is important to do this review
According to Potack 2008, there is a high demand for PEG in patients with swallowing disorders, with 160,000 to 200,000 PEG procedures performed per year in the USA. This makes PEG the procedure of choice for nutritional support in adults. The same author commented that many such procedures are performed although their benefit is dubious or limited. Moreover, as previously mentioned, there are controversies with respect to this intervention. Therefore, a systematic review is worth performing to resolve such questions.
Objectives
To evaluate the effectiveness and safety of PEG as compared to a nasogastric tube for nutrition in adults with swallowing disturbances.
Methods
Criteria for considering studies for this review
Types of studies
Randomised controlled trials comparing PEG versus a nasogastric tube for nutrition in adults with swallowing disturbances.
Types of participants
Adult patients presenting with swallowing disturbances or dysphagia and indications for nutritional support, as identified by the authors of primary studies. Patients with any underlying diseases also will be acceptable.
Types of interventions
Comparison arms of interest are as follows.
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Intervention group: percutaneous endoscopic gastrostomy performed by any method (e.g., pull and push methods, others).
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Control group: nasogastric tube irrespective of technique (e.g., conventional and looping).
Studies with radiologically inserted gastrostomy, nasojejunal tubes, and jejunal tube percutaneous endoscopy gastrostomy (JET‐PEG) will not be included in this review.
Types of outcome measures
Primary outcomes
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Intervention failures (e.g., feeding interruption, blocking or leakage of the tube, no adherence to treatment)
Secondary outcomes
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Mortality
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Complications and adverse events (e.g., aspiration, haemorrhage, wound infection, sinusitis, fistula)
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Nutritional status, as measured by any validated instrument (such as upper‐arm skin fold thickness, mid‐arm circumference, body weight, serum albumin level, haemoglobin (Ramel 2008))
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Time on enteral nutrition
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Quality of life, as measured by any validated instrument (such as EUROQoL, SF‐36 (Dorman 1997))
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Length of hospital stay
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Costs and economic issues
Search methods for identification of studies
Electronic searches
We will perform a computerised literature search in the Cochrane Central Register of Controlled Trials (CENTRAL) and other databases in The Cochrane Library, MEDLINE (from inception to present), LILACS, and EMBASE (from inception to present). A search filter to identify randomised controlled trials involving humans will be used when appropriate (see Appendix 1, for PubMed; Appendix 2 for EMBASE; and Appendix 3 for LILACS).
Search terms and their synonyms for clinical conditions of interest to us (swallowing disturbance or dysphagia) and interventions of interest (percutaneous endoscopic gastrostomy and nasogastric tube feeding) are given in Appendix 4. They will be adapted for each of the databases. There will be no language restriction in the search.
Searching other resources
A reference list of relevant studies (irrespective of study design) will be compiled to identify trials with the potential for inclusion. We will contact authors via e‐mail requesting the data from unpublished trials. We also will try to identify ongoing trials on the Current Controlled Trials Web site (www.currentcontrolledtrials.gov).
Data collection and analysis
Selection of studies
Two authors (CG, RA) will check the titles and abstracts found by the search strategy and other sources researched. Whenever titles or abstracts seem relevant to the review, they will be analysed by reading the full article. If they are truly randomised controlled trials that meet the previously stated criteria, they will be included in the review. If there remains any doubt or disagreement, all of the authors will assess the study in question.
Data extraction and management
Two authors (CG, DRW) will extract data based on CONSORT (Moher 2001). Doubts will be settled by consensus of the authors.
Assessment of risk of bias in included studies
Two authors (CG, RBA) will independently assess the methodological quality of included studies using the following items.
Selection bias
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Was the allocation sequence adequately generated?
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Was allocation adequately concealed?
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Were there systematic differences between the baseline characteristics of the groups that were compared?
Attrition bias
Were there systematic differences between groups in withdrawals from a study?
Detection bias
Were there systematic differences between groups in how outcomes were determined?
For the above three biases, studies will be classified according to their risk of systematic error
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High risk: when the appropriate method to avoid systematic error was not met.
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Moderate risk: when the appropriate method to avoid systematic error was not described or the information was not acquired by contacting the authors of primary studies.
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Low risk: when the appropriate method to avoid systematic error was met.
Performance bias will not be used as a criterion to analyse the risk of systematic error since this is not compatible with the characteristics of the intervention.
Measures of treatment effect
For dichotomous variables, relative risk (risk ratio), mean difference (MD), and 95% confidence interval (CI) will be calculated. When data from primary studies are not parametric (for example effects are reported as medians, quartiles) or without sufficient statistical information (such as standard deviations, number of patients), we will insert them into an 'Additional table' if authors do not provide the necessary information.
Unit of analysis issues
The unit of analysis is based on the individual patient (unit to be randomised for interventions to be compared). Events happening to a person more than once (for example pneumonia, bronchoaspiration) will be analysed by using rate ratio, which compares the rate of events in the two groups (PEG and NGT) by dividing one by the other. Cross‐over study designs will be analysed separately from the parallel‐group randomised controlled trials.
Dealing with missing data
For continuous and dichotomous data we will carry out available case analysis.
Assessment of heterogeneity
Statistical heterogeneity will be assessed using the I2 statistic. We will assume a statistically significant heterogeneity between the estimated effects of included studies with I2 > 50%.
Assessment of reporting biases
We will attempt to assess publication bias by preparing a funnel plot, if a sufficient number of studies is available. However, we are aware that asymmetry in the funnel plot can be associated with reasons other than that of publication bias (for example by chance, real heterogeneity, or clinical particulars inherent to each one of the included studies such as patients at high risk for the outcome)
Data synthesis
Data synthesis
Qualitative information
Qualitative information relative to methods, risk of bias, description of participants, and outcomes measures will be synthesised and inserted in the table 'Characteristics of included studies'.
Quantitative information
For dichotomous variables, the relative risk (RR) will be calculated. For continuous variables, the weighted mean difference (WMD) will be calculated when studies report their results through the same variables measured with the same instruments (same units of measure). On the other hand, when continuous data are relative to the same aspect but measured with different instruments (different and non‐interchangeable units of measure) they will be pooled through the standardised mean difference (SMD). For all statistical methods to pool data, 95% CIs will be used.
Irrespective of the nature of the data, a random‐effects statistical model will be used as we are expecting substantial clinical and methodological heterogeneity, which could generate substantial statistical heterogeneity.
Subgroup analysis and investigation of heterogeneity
We plan to carry out subgroup analyses using different NGT and PEG methods (for example pull, push, nasal loop, conventional). Heterogeneity between studies in both direction and length of estimate effect will be assumed to have a suspected causal relationship (the subgroup characteristic and the estimate effect) and will be considered in the Discussion section.
Sensitivity analysis
Sensitivity analysis is planned to examine the effects of intention‐to‐treat (ITT) analysis and available data analysis for dichotomous data. ITT analysis will be made by using imputation based on the analysis of the total number of randomised participants, irrespective of how the original study authors analysed the data. We will assume that all missing participants experienced the event. The other factors are study quality, trials reported only in abstracts, and testing for fixed and random statistical models.
