Aspirating gastric residuals causes occlusion of small-bore feeding tubes

Gastrostomy tubes: Fundamentals, periprocedural considerations, and best practices

Gastrostomy tube placement is a procedure that achieves enteral access for nutrition, decompression, and medication administration. Preprocedural evaluation and selection of patients is necessary to provide optimal benefit and reduce the risk of adverse events (AEs). Appropriate indications, contraindications, ethical considerations, and comorbidities of patients referred for gastrostomy placement should be weighed and balanced. Additionally, endoscopist should consider either a transoral or transabdominal approach is appropriate, and radiologic or surgical gastrostomy tube placement is needed. However, medical history, physical examination, and imaging prior to the procedure should be considered to tailor the appropriate approach and reduce the risk of AEs.

Wound care management: tracheostomy and gastrostomy

Percutaneous dilatational tracheostomy (PDT) and percutaneous endoscopic gastrostomy (PEG) tube placements are routine procedures performed in the intensive care units (ICUs). They are performed to facilitate care and promote healing. They also help prevent complications from prolonged endotracheal intubation and malnutrition. In most cases, both are performed simultaneously. Physicians performing them require knowledge of local anatomy, tissue and vascular relationships, along with advance bronchoscopy and endoscopy skills. Although PDTs and PEGs are considered relatively low-risk procedures, operators need to have the knowledge and skill to recognize and prevent adverse outcomes. Current published literature on post-procedural care and stoma wound management was reviewed. Available recommendations for the routine care of tracheostomy and PEG tubes are included in this review. Signs and symptoms of early PDT- and PEG-related complications and their management are discussed in detail. These include hemorrhage, infection, accidental decannulation, tube obstruction, clogging, and dislodgement. Rare, life-threatening complications are also discussed. Multidisciplinary teams are needed for improved patient care, and members should be aware of all pertinent care aspects and potential complications related to PDT and PEG placement. Each institute is strongly encouraged to have detailed protocols to standardize care. This review provides a state-of-the-art guidance on the care of patients with tracheostomies and gastrostomies specifically in the ICU setting.

CE: Monitoring Adult Patients for Intolerance to Gastric Tube Feedings

ABSTRACT

Gastric tube feeding is a common and valuable intervention for patients in a variety of care settings. While tube feeding can save the lives of patients for whom oral feeding isn't possible, intolerance to tube feeding is a potential complication. This article discusses risk factors for feeding intolerance; the assessment of signs and symptoms of feeding intolerance; the various means of assessing gastric emptying, including the practice of monitoring gastric residual volume (GRV); the controversy surrounding GRV monitoring in assessing feeding tolerance; and the special considerations for monitoring feeding tolerance in acutely and critically ill adults with coronavirus disease 2019. The author, a nurse researcher with extensive experience in the area of enteral feeding, briefly summarizes recommendations and guidelines for enteral feeding published by national and international health care organizations between 2015 and 2020, and offers her perspective on best nursing practices for monitoring food tolerance in adults.

The correlation between gastric residual volumes and markers of gastric emptying: a post-hoc analysis of a randomized clinical trial

BACKGROUND

The correlation between gastric residual volumes (GRV) and markers of gastric emptying (GE) in critically ill patients is unclear. This is especially true for ICU surgical patients as they are underrepresented in previous studies.

METHODS

We conducted a post-hoc analysis of a multicenter trial that investigated the effectiveness of a promotility drug in increasing enteral nutrition intake. Pharmacokinetic markers of GE [3-O-methylglucose (3-OMG) and acetaminophen] were correlated with GRV measurements. High-GRV was defined as one episode of >400 mL or two consecutive episodes of >250 mL, and delayed GE was defined as <20^th percentile of the pharmacokinetic GE marker that had the strongest correlation with GE.

RESULTS

Out of 77 patients, 8 (10.4%) had high-GRV, and 15 (19.5%) had delayed GE. 3-OMG concentration at 60 mins had the strongest correlation with GRV (Rho: - 0.631), and high-GRV had low sensitivity (46.7%) but high specificity (98.4%) in discriminating delayed GE. The positive (87.5%) and negative (88.4%) predictive values were similar. There was a small sample of surgical patients (n = 14, 18.2%), and they had a significantly higher incidence of high-GRV (29% vs 6%, P: 0.032) and a trend towards delayed GE (36% vs 16%, p: 0.132) when compared to medical patients.

CONCLUSION

GRV reflects GE, and high-GRV is an acceptable surrogate marker of delayed GE. Based on our preliminary observation, surgical patients may have a higher risk of high-GRV and delayed GE. In summary, GRV should be monitored to determine if complex investigations or therapeutic interventions are warranted. This article is protected by copyright. All rights reserved.

Does ultrasonographic assessment of gastric antrum correlate with gastric residual volume in critically ill patients? A prospective observational study

This study aimed to evaluate the relationship between ultrasonographic gastric antral measurements and aspirated gastric residual volume (GRV) in mechanically ventilated critically ill patients receiving enteral nutrition (EN). This prospective observational study included 56 enterally-fed critically ill patients in one-year period. All imaging procedures were done at 30-degree head-of-bed elevation and supine position on epigastric region of abdomen with 2.5-6 MHz convex-array probe just before routine GRV aspiration. The antral cross-sectional area (CSA) was calculated by measuring the anteroposterior (dAP) and craniocaudal diameters (dCC) of the gastric antrum. Total 283 ultrasonographic gastric antrum imaging procedures were done. In only eight (2.82%) attempts, the antrum could not be visualized due to inhibition from intra-gastric air or gas in the surrounding intestinal lumen. The calculated mean antral CSA was 568.15 ± 348.37 mm² (103.43-2,846.30). The antral CSA correlated significantly with aspirated GRV, and the antral CSA increased linearly with increasing aspirated GRV (R² = 0.73, p < 0.0001). In Receiver operating characteristic (ROC) analysis of antral CSA ≥ 920 mm² (mean + 1*SD) for estimating aspirated GRV, the area under the curve (AUC) was 0.848 (95% CI, 0.76 ~ 0.93) (p < 0.0001), and ROC analysis of antral CSA to discriminate aspirated GRV ≥ 250 mL showed a significant relation (AUC = 0.969, 95% CI 0.94 ~ 0.99, p < 0.0001). Ultrasonographic measurement of gastric antral CSA is an easy and reliable bedside procedure to estimate GRV in critically ill patients receiving EN in 30-degree head-of-bed elevation and supine position. Trial registration number: NCT04413474, date of registration: June 17, 2020, retrospectively registered.

Small-bore feeding tube versus large-bore sump tube for early enteral nutrition in mechanically ventilated patients: A nationwide inpatient database study

BACKGROUND & AIMS

When physicians start nasogastric tube feeding in mechanically ventilated patients, they have two choices of feeding tube device: a large-bore sump tube or a small-bore feeding tube. Some physicians may prefer to initiate enteral nutrition via the large-bore sump tube that is already in place, and others may prefer to use the small-bore feeding tube. However, it remains unknown whether small-bore feeding tubes or large-bore sump tubes are better for early enteral nutrition. The present study aimed to compare outcomes between these two types of feeding tubes in mechanically ventilated patients.

METHODS

Using the Japanese Diagnosis Procedure Combination inpatient database from July 2010 to March 2018, we identified adult patients who underwent invasive mechanical ventilation for ≥2 days in intensive care units and received nasogastric tube feeding within 2 days of starting mechanical ventilation. We categorized these patients as receiving early enteral nutrition via small-bore feeding tube (8- to 12-Fr single-lumen tubes) or via large-bore sump tube. Propensity score-matched analyses were performed to compare 28-day in-hospital mortality and hospital-acquired pneumonia between the two groups.

RESULTS

A total of 79,656 patients were included. Of these patients, 20,178 (25%) were in the small-bore feeding tube group. One-to-one propensity score matching created 20,061 matched pairs. Compared with those in the large-bore sump tube group, patients in the small-bore feeding tube group had significantly higher 28-day in-hospital mortality (17.0% versus 15.6%; hazard ratio, 1.08; 95% confidence interval, 1.03 to 1.14) and a significantly higher prevalence of hospital-acquired pneumonia (9.3% versus 8.5%; odds ratio, 1.11; 95% confidence interval, 1.02 to 1.21).

CONCLUSIONS

This nationwide observational study suggests that small-bore feeding tubes may not be associated with better clinical outcomes but rather with increased mortality and hospital-acquired pneumonia. Because of the uncertainty regarding the mechanism of our findings, further studies are warranted.

Exemplars Illustrating De-implementation of Tradition-Based Practices

Clinical practice must be based on evidence. When evidence suggests that a certain practice may be ineffective or even harmful, that practice should be discontinued. The Choosing Wisely campaign, an initiative of the ABIM (American Board of Internal Medicine) Foundation, is intended to bring attention to tradition-based practices, or "sacred cows," which lack evidence to support their ongoing use. The complex process of discontinuing or reducing the use of tradition-based practices is known as "de-implementation." Recognizing the importance of de-implementation is necessary to fully understand evidence-based practice. This article explores the de-implementation process, examining its barriers and facilitators. Three critical care exemplars of tradition-based practices are presented and examined through the lens of de-implementation. Barriers and facilitators related to de-implementing these tradition-based practices are described, with an emphasis on the roles of various stakeholders and the need to overcome cognitive dissonance and psychological bias.

Enteral tolerance in critically ill patients

Enteral nutrition (EN) can maintain the structure and function of the gastrointestinal mucosa better than parenteral nutrition. In critically ill patients, EN must be discontinued or interrupted, if gastrointestinal complications, particularly vomiting and bowel movement disorders, do not resolve with appropriate management. To avoid such gastrointestinal complications, EN should be started as soon as possible with a small amount of EN first and gradually increased. EN itself may also promote intestinal peristalsis. The measures to decrease the risk of reflux and aspiration include elevation the head of the bed (30° to 45°), switch to continuous administration, administration of prokinetic drugs or narcotic antagonists to promote gastrointestinal motility, and switch to jejunal access (postpyloric route). Moreover, the control of bowel movement is also important for intensive care and management. In particular, prolonged diarrhea can cause deficiency in nutrient absorption, malnutrition, and increase in mortality. In addition, diarrhea may cause a decrease the circulating blood volume, metabolic acidosis, electrolyte abnormalities, and contamination of surgical wounds and pressure ulcers. If diarrhea occurs in critically ill patients on EN management, it is important to determine whether diarrhea is EN-related or not. After ruling out the other causes of diarrhea, the measures to prevent EN-related diarrhea include switch to continuous infusion, switch to gastric feeding, adjustment of agents that improve gastrointestinal peristalsis or laxative, administration of antidiarrheal drugs, changing the type of EN formula, and semisolidification of EN formula. One of the best ways to success for EN management is to continue as long as possible without interruption and discontinuation of EN easily by appropriate measures, even if gastrointestinal complications occur.

Measuring gastric residual volumes in critically ill burn patients - A systematic review

PURPOSE

Measuring gastric residual volumes (GRV) is common in intensive care units (ICU) in patients receiving enteral nutrition (EN) and are a common source of feeding interruptions. Interruptions in EN yield adverse outcomes and are an area of improvement in burn care. The objectives of this study are to summarize the literature's ICU GRV practices and offer practical suggestions to GRV management in the burn patient.

METHODS

PubMed, SCOPUS, and OvidSP Medline were systematically reviewed using the keywords: burns; thermal injury; gastric residual volume; enteral feeding; tube feeding; enteral nutrition; gastric intolerance; ICU; critical illness. Reviews, case reports, and consensus and opinion papers were excluded.

RESULTS

26 articles were identified. Six burn-specific studies were identified. GRV practices vary widely and are a common cause of EN interruption. Elevated GRVs do not equate to gastrointestinal intolerance and do not always reflect aspiration risk.

CONCLUSIONS

We advocate a GRV threshold of 500mL should be used to optimize the benefits of EN in burn ICUs. A single incident of elevated GRVs should not mandate immediate EN rate reduction or cessation but should prompt a thoughtful examination of secondary causes of gastrointestinal intolerance. Randomized controlled trials are needed to define the ideal GRV threshold and re-evaluate its role in burn care.

Critical Care Nutrition Support Best Practices: Key Differences Between Canadian and American Guidelines

Since 2015, Society of Critical Care Medicine/American Society for Parenteral and Enteral Nutrition and Canadian critical care nutrition support guidelines have both been updated. Despite a similar evidentiary basis, there remain key differences between guideline recommendations. These differences in recommendations may pose confusion for the clinician and may encumber widespread applicability. The aim of this review was to enhance practitioner confidence in applying critical care nutrition support guidelines to patient care in their settings by outlining the similarities and differences between the American and Canadian methods for guideline development and describing the key differences and reasons behind the differences.

Total Parenteral and Enteral Nutrition in the ICU: Evolving Concepts

Appropriate nutrition in the hospital setting, particularly in critically ill patients, has long been tied to improving clinical outcomes. During critical illness, inflammatory mediators and cytokines lead to the creation of a catabolic state to facilitate the use of endogenous energy sources to meet increased energy demands. This process results in increasing the likelihood of overfeeding. The literature has revealed exponential advances in understanding the molecular basis of nutritional support and evolution of clinical protocols aimed at treating artificial nutritional support as a therapeutic intervention, preventing loss of lean body mass and metabolic deterioration to improve clinical outcomes in the critically ill.

Aspiration and the Risk of Ventilator-Associated Pneumonia

Ventilator-associated pneumonia (VAP) is a major concern in the intensive care unit. It is estimated that the risk of developing VAP may be as high as 1% per ventilated day, and the attributable mortality approaches 50% in some series. A growing body of evidence implicates the role of microaspiration of contaminated oropharyngeal and perhaps gastroesophageal secretions into the airways as an integral step in the pathogenesis of VAP. In patients who have been intubated and mechanically ventilated for >72 hours, the majority of VAP is caused by enteric gram-negative organisms, presumably of gastrointestinal origin. As a result, strategies designed to minimize the risk of these contaminated secretions into the normally sterile airways are of paramount importance in terms of VAP prevention. This review highlights the important etiological role of the gut in the development of VAP and also discusses the evidence behind interventions that may modulate the risk of both aspiration and subsequent VAP.

ASPEN Safe Practices for Enteral Nutrition Therapy [Formula: see text]

Enteral nutrition (EN) is a valuable clinical intervention for patients of all ages in a variety of care settings. Along with its many outcome benefits come the potential for adverse effects. These safety issues are the result of clinical complications and of process-related errors. The latter can occur at any step from patient assessment, prescribing, and order review, to product selection, labeling, and administration. To maximize the benefits of EN while minimizing adverse events requires that a systematic approach of care be in place. This includes open communication, standardization, and incorporation of best practices into the EN process. This document provides recommendations based on the available evidence and expert consensus for safe practices, across each step of the process, for all those involved in caring for patients receiving EN.

CIRSE Standards of Practice Guidelines on Gastrostomy

PURPOSE

Surgical Gastrostomy has been around since the 19th century but in 1980 the first successful percutaneous endoscopic gastrostomy was reported. A year later the first successful percutaneous gastrostomy was performed using fluoroscopic guidance. The technique for percutaneous insertion and the equipment used has been refined since then and it is now considered the gold standard for gastrostomy insertion. Here we present guidelines for image-guided enteral feeding tubes in adults.

MATERIAL AND METHOD

We performed a review and analysis of the scientific literature, other national and international guidelines and expert opinion.

RESULTS

Studies have shown fluoroscopic techniques have consistently higher success rates with lower rates of major complications than endoscopic techniques. However, the Achilles' heel of many fluoroscopic techniques is the requirement for smaller gastrostomy tube sizes resulting in them being more prone to blockages and thus requiring further intervention.

CONCLUSION

Radiological feeding tube insertion is a safe and effective procedure. Success rates are higher, and complication rates lower than PEG or surgical gastrostomy tube placement and innovative techniques for gastric and jejunal access mean that there are very few cases in which RIG is not possible. The principal weakness of radiologically inserted gastrostomies is the limitiation on tube size which leads to a higher rate of tube blockage. Per-oral image-guided gastrostomies have to an extent addressed this but have not been popularised. Currently many centres still consider endoscopic gastrostomies as the first line unless patients are too unwell to undergo this procedure or previous attempts have failed, in which case radioloically inserted gastrostomies are the technique of choice.

ACG Clinical Guideline: Nutrition Therapy in the Adult Hospitalized Patient

The value of nutrition therapy for the adult hospitalized patient is derived from the outcome benefits achieved by the delivery of early enteral feeding. Nutritional assessment should identify those patients at high nutritional risk, determined by both disease severity and nutritional status. For such patients if they are unable to maintain volitional intake, enteral access should be attained and enteral nutrition (EN) initiated within 24-48 h of admission. Orogastric or nasogastric feeding is most appropriate when starting EN, switching to post-pyloric or deep jejunal feeding only in those patients who are intolerant of gastric feeds or at high risk for aspiration. Percutaneous access should be used for those patients anticipated to require EN for >4 weeks. Patients receiving EN should be monitored for risk of aspiration, tolerance, and adequacy of feeding (determined by percent of goal calories and protein delivered). Intentional permissive underfeeding (and even trophic feeding) is appropriate temporarily for certain subsets of hospitalized patients. Although a standard polymeric formula should be used routinely in most patients, an immune-modulating formula (with arginine and fish oil) should be reserved for patients who have had major surgery in a surgical ICU setting. Adequacy of nutrition therapy is enhanced by establishing nurse-driven enteral feeding protocols, increasing delivery by volume-based or top-down feeding strategies, minimizing interruptions, and eliminating the practice of gastric residual volumes. Parenteral nutrition should be used in patients at high nutritional risk when EN is not feasible or after the first week of hospitalization if EN is not sufficient. Because of their knowledge base and skill set, the gastroenterologist endoscopist is an asset to the Nutrition Support Team and should participate in providing optimal nutrition therapy to the hospitalized adult patient.

Enteral Nutrition for Adults in the Hospital Setting

In patients unable to tolerate oral intake, multiple options of nutrient delivery are available to the clinician. Administration of enteral nutrition (EN) has long been considered the standard of care for nutrition support among patients unable to meet energy and protein requirements orally. Healthcare practitioners must make careful decisions related to ordering, administering, and monitoring EN therapy. In the hospital setting, the registered dietitian is a key resource in enteral formula selection and method of administration, monitoring for and troubleshooting EN-related complications, and transitioning to oral feeding. The hospital setting also presents many unique challenges in providing optimal nutrition to the enterally fed patient.

Gastric residual volume in critically ill patients: a dead marker or still alive?

Early enteral nutrition (EN) is consistently recommended as first-line nutrition therapy in critically ill patients since it favorably alters outcome, providing both nutrition and nonnutrition benefits. However, critically ill patients receiving mechanical ventilation are at risk for regurgitation, pulmonary aspiration, and eventually ventilator-associated pneumonia (VAP). EN may increase these risks when gastrointestinal (GI) dysfunction is present. Gastric residual volume (GRV) is considered a surrogate parameter of GI dysfunction during the progression of enteral feeding in the early phase of critical illness and beyond. By monitoring GRV, clinicians may detect patients with delayed gastric emptying earlier and intervene with strategies that minimize or prevent VAP as one of the major risks of EN. The value of periodic GRV measurements with regard to risk reduction of VAP incidence has frequently been questioned in the past years. Increasing the GRV threshold before interrupting gastric feeding results in marginal increases in EN delivery. More recently, a large randomized clinical trial revealed that abandoning GRV monitoring did not negatively affect clinical outcomes (including VAP) in mechanically ventilated patients. The results have revived the discussion on the role of GRV monitoring in critically ill, mechanically ventilated patients receiving early EN. This review summarizes the most recent clinical evidence on the use of GRV monitoring in critically ill patients. Based on the clinical evidence, it discusses the pros and cons and further addresses whether GRV is a dead marker or still alive for the nutrition management of critically ill patients.

Gastroenteric tube feeding: Techniques, problems and solutions

Gastroenteric tube feeding plays a major role in the management of patients with poor voluntary intake, chronic neurological or mechanical dysphagia or gut dysfunction, and patients who are critically ill. However, despite the benefits and widespread use of enteral tube feeding, some patients experience complications. This review aims to discuss and compare current knowledge regarding the clinical application of enteral tube feeding, together with associated complications and special aspects. We conducted an extensive literature search on PubMed, Embase and Medline using index terms relating to enteral access, enteral feeding/nutrition, tube feeding, percutaneous endoscopic gastrostomy/jejunostomy, endoscopic nasoenteric tube, nasogastric tube, and refeeding syndrome. The literature showed common routes of enteral access to include nasoenteral tube, gastrostomy and jejunostomy, while complications fall into four major categories: mechanical, e.g., tube blockage or removal; gastrointestinal, e.g., diarrhea; infectious e.g., aspiration pneumonia, tube site infection; and metabolic, e.g., refeeding syndrome, hyperglycemia. Although the type and frequency of complications arising from tube feeding vary considerably according to the chosen access route, gastrointestinal complications are without doubt the most common. Complications associated with enteral tube feeding can be reduced by careful observance of guidelines, including those related to food composition, administration rate, portion size, food temperature and patient supervision.

Examination of accuracy in the assessment of gastric residual volume: a simulated, controlled study

BACKGROUND

Increased gastric content from enteral nutrition intolerance is thought to place patients at risk for pulmonary aspiration. Although considered a questionable practice, blind gastric tube aspiration is the most common approach to measure gastric content. This simulated study evaluated the accuracy of residual volume (RV) assessment via tube aspirations made from known volumes by controlling the syringe pull technique, feeding tube properties, fluid viscosity, and placement of tubes in the fluid.

MATERIALS AND METHODS

This study was conducted in a metrology laboratory. Aspirates were obtained using a force measurement test system to control force of the syringe pull technique using 3 different procedures (slow 10 inches per minute [ipm], intermittent 10 ipm, and fast 40 ipm). Four different feeding tubes, 10 Fr and 18 Fr, each made of polyurethane and polyvinyl chloride, were placed in varying depths of 100 mL of either water or formula. The effect of fluid viscosity was also examined.

RESULTS

Overall, 108 RVs were analyzed using a force measurement test system. Actual content of RV was underestimated 19% on average and varied across tube size and viscosity. Intermittent and slow syringe pull techniques yielded greater aspirate quantities, although neither technique aspirated the full amount of volume available. The 10 Fr feeding tubes yielded larger RVs in more viscous fluid, yet the 18 Fr tubes performed better with fluids of lower viscosity.

CONCLUSIONS

Based on this simulation, RV assessment does not accurately reflect the total volume of the contents available and, therefore, the clinical utility of this assessment should be further investigated.

Nasogastric tube feedings and gastric residual volume: a regional survey

OBJECTIVES

To maintain adequate nutrition for patients who are in need, enteral feeding via nasogastric tube (NGT) is necessary. Although the literature suggests the safety of continued NGT feeding at a gastric residual volume of <400 mL, inconsistencies in withholding tube feeding based on residual volume have been observed in clinical practice. We performed a regional survey to determine the range of current practice among nursing staff regarding the decision to withhold NGT feeding based on residual volume and the factors that influence the decision-making process.

METHODS

A questionnaire was designed to evaluate nursing practice patterns regarding the decision of withholding NGT feeding based on a certain residual volume, which was distributed to the nursing staff at all major hospitals in the Oklahoma City metropolitan area. Statistical analysis was done with the Fisher exact test. All of the statistical tests were carried out at α = 0.05.

RESULTS

A total of 582 nurses completed the survey. Residual volumes (milliliters) resulting in the termination of NGT feeding occurred in 89% of nurses at volumes <300 mL and only 3% of nurses at volumes >400 mL. Three main reasons for nurses to withhold NGT feeding were risk of aspiration (90%), potential feeding intolerance (81%), and risk of regurgitation (67%). Other less common concerns were abdominal distension and abdominal discomfort.

CONCLUSIONS

The decision of withholding NGT feeding varied among the nursing staff that were surveyed. A consensus is necessary for the standardization of withholding NGT feeding in clinical practice among nursing staff.

Motility disorders of the upper gastrointestinal tract in the intensive care unit: pathophysiology and contemporary management

Upper gastrointestinal (GI) dysmotility, an entity commonly found in the intensive care unit setting, can lead to insufficient nutrient intake while increasing the risk of infection and mortality. Further, overcoming the altered motility with early enteral feeding is associated with a reduced incidence of infectious complications in intensive care unit patients. Upper GI dysmotility in critical care patients is a common occurrence, and there are many causes for this problem, which affects a very heterogenous population with a multitude of underlying medical abnormalities. Therefore, it is of utmost importance to identify this widespread problem and subsequently institute a proper therapy as rapidly as possible. Prokinetic pharmacotherapies are currently the mainstay for the management of disordered upper GI motility. Future therapies, aimed at the underlying pathophysiology of this complex problem, are under investigation. These aim is to reduce the side effects of the currently available options, while improving on nutrition delivery in the critically ill. This review discusses the pathophysiology, clinical manifestations, diagnosis, and treatment of upper GI motility disturbances in the critically ill.

Clinical guidelines and nutrition therapy: better understanding and greater application to patient care

The volume of clinical guidelines produced by national and international societies has virtually exploded in the literature over the past decade. The most important aspect of guidelines is transparency, that is, the connection between the recommendation or guideline statement and the underlying supportive studies from the literature should be transparent. Clinical guidelines should help organize the literature, identify key areas of patient management, and provide a framework with which the clinician may operate. The reader of a guideline should embrace controversy, trace back and review the underlying literature, and then determine whether practice should be altered as a result of the guideline recommendations. The purpose of this article is to understand the derivation of clinical guidelines, to learn how to resolve controversy or differences between guidelines and clinical practice, and to learn steps to apply the guidelines to an individual institution or clinical practice.

Gastric residual volumes in critical illness: what do they really mean?

The practice of measuring gastric residual volumes (GRVs) has become a routine part of enteral feeding protocols in the critical care setting. However, little scientific evidence indicates that their use improves patient outcomes. The use of GRVs is more of a tradition, which unfortunately guides the delivery of enteral nutrition (EN). The practice of GRVs is predicated on several flawed assumptions. Using GRVs in hospitalized patients assumes that the practice is well standardized, that GRVs reliably and accurately measure gastric contents, and that they sufficiently distinguish normal from abnormal emptying. The practice also assumes that GRVs are easy to interpret, that a tight correlation exists between GRVs and aspiration, and that continuing EN after a high value for GRV is obtained leads to pneumonia and adverse patient outcomes. And finally, clinicians assume that GRVs are an inexpensive "poor man's test" for determining tolerance of EN. This article reviews studies showing the fallacies of these assumptions. Although clinicians are unlikely to stop using GRVs, interpretation of these must be modified so as not to interrupt the delivery of EN. Using a protocol that directs appropriate responses to elevated GRVs should promote the delivery of EN and improve patient outcome.

Impact of not measuring residual gastric volume in mechanically ventilated patients receiving early enteral feeding: a prospective before-after study

BACKGROUND

Monitoring of residual gastric volume (RGV) to prevent aspiration is standard practice in mechanically ventilated patients receiving early enteral nutrition (EN). No data are available to support a correlation between RGV and adverse event rates. We evaluated whether not measuring RGV affected EN delivery, vomiting, or risk of nosocomial pneumonia.

METHODS

Two hundred and five eligible patients with nasogastric feeding within 48 hours after intubation were included in a 7-day prospective before-after study. Continuous 24-hour nutrition was started at 25 mL/h then increased by 25 mL/h every 6 hours, to 85 mL/h. In both groups, intolerance was treated with erythromycin (250 mg IV/6 h) and a delivery rate decrease to the previously well-tolerated rate. RGV monitoring was used during the first study period (n = 102), but not during the subsequent intervention period (n = 103). Intolerance was defined as RGV >250 mL/6 h or vomiting in the standard-practice group and as vomiting in the intervention group.

RESULTS

Groups were similar for baseline characteristics. Median daily volume of enteral feeding was higher in the intervention group (1489; interquartile range [IQR], 1349-1647) than in the controls (1381; IQR, 1151-1591; P = .002). Intolerance occurred in 47 (46.1%) controls and 27 (26.2%) intervention patients (P = .004). The vomiting rate did not differ between controls and intervention group patients (24.5% vs 26.2%, respectively; P = .34), and neither was a difference found for ventilator-associated pneumonia (19.6% vs 18.4%; P = .86).

CONCLUSION

Early EN without RGV monitoring in mechanically ventilated patients improves the delivery of enteral feeding and may not increase vomiting or ventilator-associated pneumonia.

To return or to discard? Randomised trial on gastric residual volume management

BACKGROUND

The control of gastric residual volume (GRV) is a common nursing intervention in intensive care; however the literature shows a wide variation in clinical practice regarding the management of GRV, potentially affecting patients' clinical outcomes. The aim of this study is to determine the effect of returning or discarding GRV, on gastric emptying delays and feeding, electrolyte and comfort outcomes in critically ill patients.

METHOD

A randomised, prospective, clinical trial design was used to study 125 critically ill patients, assigned to the return or the discard group. Main outcome measure was delayed gastric emptying. Feeding outcomes were determined measuring intolerance indicators, feeding delays and feeding potential complications. Fluid and electrolyte measures included serum potassium, glycaemia control and fluid balance. Discomfort was identified by significant changes in vital signs.

RESULTS

Patients in both groups presented similar mean GRV with no significant differences found (p=0.111), but participants in the intervention arm showed a lower incidence and severity of delayed gastric emptying episodes (p=0.001). No significant differences were found for the rest of outcome measurements, except for hyperglycaemia.

CONCLUSIONS

The results of this study support the recommendation to reintroduce gastric content aspirated to improve GRV management without increasing the risk for potential complications.

Evaluation of Delivery of Enteral Nutrition in Critically Ill Patients Receiving Mechanical Ventilation

Background Published reports consistently describe incomplete delivery of prescribed enteral nutrition. Which specific step in the process delays or interferes with the administration of a full dose of nutrients is unclear.

Objectives To assess factors associated with interruptions in enteral nutrition in critically ill patients receiving mechanical ventilation.

Methods An observational prospective study of 59 consecutive patients who required mechanical ventilation and were receiving enteral nutrition was done in an 18-bed medical intensive care unit of an academic center. Data were collected prospectively on standardized forms. Steps involved in the feeding process from admission to discharge were recorded, each step was timed, and delivery of nutrition was quantified.

Results Patients received approximately 50% (mean, 1106.3; SD, 885.9 Cal) of the prescribed caloric needs. Enteral nutrition was interrupted 27.3% of the available time. A mean of 1.13 interruptions occurred per patient per day; enteral nutrition was interrupted a mean of 6 (SD, 0.9) hours per patient each day. Prolonged interruptions were mainly associated with problems related to small-bore feeding tubes (25.5%), increased residual volumes (13.3%), weaning (11.7%), and other reasons (22.8%). Placement and confirmation of placement of the small-bore feeding tube were significant causes of incomplete delivery of nutrients on the day of admission.

Conclusions Delivery of enteral nutrition in critically ill patients receiving mechanical ventilation is interrupted by practices embedded in the care of these patients. Evaluation of the process reveals areas to improve the delivery of enteral nutrition.

Enteral access options and management in the patient with intestinal failure

Intestinal failure refers to a condition in which inadequate digestion and/or absorption of nutrients leads to malnutrition and/or dehydration. Enteral access is occasionally used in patients with intestinal failure either for the purpose of providing nutrition or decompressing the gut. As a consequence, it is important that clinicians caring for these highly complex patients be knowledgeable in enteral access options and experienced in the subsequent care of these tubes. In this review, enteral access options and the potential complications associated with their use will be reviewed. Importantly, this information is relevant to both the pediatric and adult patient with intestinal failure.

Clinical evaluation of a newly designed nasogastric enteral feeding tube

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

[Measurement of residual gastric volume: in search of better evidence]

INTRODUCTION

Measurement of residual gastric volume is a frequent practice in chronic patients, but there is lack of consensus on the convenience of reintroducing or discarding aspirated gastric content (AGC).

OBJECTIVE

Determine the grade of scientific evidence on the efficacy of two interventions -reintroduction/rejection- of AGC in chronic patients.

MATERIAL AND METHODS

Systematic review of the evidence available on the convenience of reintroducing or discarding ACG.

PROCEDURE

a) establishment of inclusion/exclusion criteria; b) determination of the search strategy (keywords and itineraries); c) dumping of databases: MEDLINE, CINAHL, CUIDEN, IME, SCIELO and COCHRANE. Search for indirect method and manual dumping of indexes; d) independent and contrasted critical reading, using the CASPe template; and e) contrast of critical analysis results.

RESULTS

Search itineraries generate more than 800 references that once purged make it possible to select 54. After reading them, only 4 really focused on the questions related with the reintroduction/rejection of AGC: 2 revisions, 1 observational study and a random clinical trial with a small sample. Meta-analysis techniques could not be used due to the heterogeneity of these studies. Thus, the results of the study were analyzed separately. Using this procedure, a final result was obtained that showed a low grade of scientific evidence.

CONCLUSIONS

There is limited scientific evidence on the convenience, safety and benefits of both interventions. It is difficult to establish a care protocol, so that we suggest performing an experimental study to establish the indications and contraindications of both interventions.

Acute complications associated with bedside placement of feeding tubes

Several types of feeding tubes can be placed at a patient's bedside; examples include nasogastric, nasointestinal, gastrostomy, and jejunostomy tubes. Nasoenteral tubes can be placed blindly at bedside or with the assistance of placement devices. Nasoenteric tubes can also be placed via fluoroscopy and endoscopy. Gastrostomy and jejunostomy tubes can be placed using endoscopic techniques. This paper will describe the indications and contraindications for different types of tubes that can be placed at the bedside and complications associated with tube placement. Complications associated with nasoenteral tubes include inadvertent malpositioning of the tube, epistaxis, sinusitis, inadvertent tube removal, tube clogging, tube-feeding-associated diarrhea, and aspiration pneumonia. Complications from percutaneous gastrostomy and jejunostomy tube placements include procedure-related mishaps, site infection, leakage, buried bumper syndrome, tube malfunction, and inadvertent removal. These complications will be reviewed, along with a discussion of incidence, cause, treatment, and prevention approaches.