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

Ultrasonography-guided post-pyloric feeding tube insertion in medical intensive care unit patients

In this study, we investigated placement rate, complication rate and time spent of successful post-pyloric enteral feeding (PPEF) tube insertion procedure guided by ultrasonography (USG). The patients who required enteral nutrition and who admitted to medical intensive care unit (MICU) of Gazi University Hospital were included to this single-center, prospective, cohort study. It was aimed to insert the enteral feeding tube into the proximal duodenum as the post-pyloric area by ultrasonography guidance. During the PPEF tube insertion procedure, the linear probe was used to display the proximal esophagus and the convex probe was used to display the post-pyloric area, antrum and pyloric channel. 33 patients were included in this study. The median age was 68 [IQR 52-79] years. There were 17 (51.5%) woman and 22 (66.7%) intubated patients. The enteral feeding tube was successfully passed into the post-pyloric area in 29 (87.9%) patients with this technique. The median time of successful feeding tube insertion was 14 [IQR 10-25] min. The median level of the enteral feeding tube was 74 [IQR 70-76] cm. in successful placement. There was no significant difference in insertion time according to gender (female vs male; 10 [IQR 8-20] min. vs 17 [IQR 12-25] min., p = 0.052) and endotracheal intubation status (intubated vs non-intubated; 14 [IQR 10-25] min. vs 12 [IQR 10-25] min., p = 0.985). Only one complication was seen during study (self-limiting epistaxis in one patient). PPEF tube insertion under USG guidance could ensure the initiation of enteral feeding safely and rapidly without exposure to radiation in ICU patients.

Should I Start With A Postpyloric Enteral Nutrition Modality?

Nutrition therapy is a key element in the management of malnourished and critically ill patients. Although many aspects of enteral nutrition (EN) have been well defined by research, with clear recommendations by 3 major society guidelines, EN delivery method remains a topic for debate. The goal of this manuscript is to concisely review gastric vs postpyloric enteral feeding in critically ill adult patients and provide a set of recommendations to individualize EN delivery method based on patient characteristics and specific needs.

Clinical nutrition for the gastroenterologist: bedside strategies for feeding the hospitalized patient

PURPOSE OF REVIEW

The timing, advancement, and use of appropriate monitors determine whether the hospitalized patient experiences the full benefit of nutritional therapy. This article reviews management strategies in delivering the optimal nutrition regimen capable of improving outcomes in the hospitalized patient.

RECENT FINDINGS

Enteral nutrition should be initiated in the first 24-36 h after admission. Determination of nutritional risk helps guide the urgency with which nutritional therapy is provided and predicts the likelihood for difficulties in delivering the prescribed regimen. Feeds should be advanced slowly over 3-4 days to meet 70-80% of goal for calories (20 kcal/kg/day) and 100% for protein (2.0 gm/kg/day). Reaching protein goals early on may be more important than achieving energy goals. Patients should be monitored for hemodynamic stability, evidence of refeeding syndrome, and tolerance in the setting of gastrointestinal dysfunction. Parenteral nutrition should be utilized in select high-risk patients where the feasibility of full enteral nutrition is questioned.

SUMMARY

Timing with early initiation of enteral nutrition, avoidance of overfeeding, and step-wise advancement of feeds are required to safely realize the benefits of such therapy.

Gastrointestinal Dysfunction and Feeding Intolerance in Critical Illness: Do We Need an Objective Scoring System?

PURPOSE OF REVIEW

Efforts to provide early enteral nutrition in critical illness are thwarted by gastrointestinal dysfunction and feeding intolerance. While many of the signs and symptoms of this dysfunction reflect gastroparesis and intestinal dysmotility, other symptoms which may or may not be related are often included such as diarrhea, bleeding, and intra-abdominal hypertension. This paper discusses the need to monitor tolerance of nutritional therapy in the critical care setting and reviews the results of those clinical trials which have helped establish objective measures, define feeding intolerance, and provide a tool to guide continued delivery of the enteral regimen.

RECENT FINDINGS

While definitions vary, the presence of gastrointestinal dysfunction and feeding intolerance correlates with adverse clinical outcomes, including prolonged duration of mechanical ventilation, greater length of stay in the intensive care unit, and increased mortality. Despite their prognostic value, it is not clear to what extent these scoring systems should direct nutritional therapy. The clinician should be astute in the careful selection of monitors, in identifying and addressing signs and symptoms of intolerance, and by responding appropriately with feeding strategies that are effective and safe. Early enteral feeding in critical illness has been shown to be optimized by following protocols which allow monitoring patient tolerance while providing individualized care.

Targeting IL-17A Improves the Dysmotility of the Small Intestine and Alleviates the Injury of the Interstitial Cells of Cajal during Sepsis

Intestinal dysmotility is a frequent complication during sepsis and plays an important role in the development of secondary infections and multiple organ failure. However, the central mechanisms underlying this process have not been well elucidated. Currently, effective therapies are still lacking for the treatment of sepsis-induced intestinal dysmotility. In this study, we found that the activation of IL-17 signaling within the muscularis propria might be associated with dysmotility of the small intestine during polymicrobial sepsis. Furthermore, we demonstrated that targeting IL-17A partially rescued the motility of the small intestine and alleviated interstitial cells of Cajal (ICC) injury during sepsis. The blockade of IL-17A suppressed the dominant sepsis-induced infiltration of M1-polarized macrophages into the muscularis. Additionally, impaired ICC survival may be associated with the oxidative stress injury induced by dominant infiltration of M1-polarized macrophages. Our findings reveal the important role of the IL-17 signaling pathway in the small intestine during sepsis and provide clues for developing a novel therapeutic strategy for treating gastrointestinal dysmotility during sepsis.

Effect of sucralfate on gastric permeability in an ex vivo model of stress-related mucosal disease in dogs

BACKGROUND

Sucralfate is a gastroprotectant with no known systemic effects. The efficacy of sucralfate for prevention and treatment of stress-related mucosal diseases (SRMD) in dogs is unknown.

HYPOTHESIS/OBJECTIVES

To develop a canine ex vivo model of SRMD and to determine the effect of sucralfate on mucosal barrier function in this model.

ANIMALS

Gastric antral mucosa was collected immediately postmortem from 29 random-source apparently healthy dogs euthanized at a local animal control facility.

METHODS

Randomized experimental trial. Sucralfate (100 mg/mL) was applied to ex vivo canine gastric mucosa concurrent with and after acid injury. Barrier function was assessed by measurement of transepithelial electrical resistance (TER) and radiolabeled mannitol flux.

RESULTS

Application of acidified Ringers solution to the mucosal side of gastric antrum caused a reduction in gastric barrier function, and washout of acidified Ringers solution allowed recovery of barrier function (TER: 34.0 ± 2.8% of control at maximum injury, 71.3 ± 5.5% at recovery, P < .001). Sucralfate application at the time of injury or after injury significantly hastened recovery of barrier function (TER: 118.0 ± 15.2% of control at maximum injury, P < .001 and 111.0 ± 15.5% at recovery, P = .35).

CONCLUSIONS AND CLINICAL IMPORTANCE

Sucralfate appeared effective at restoring defects in gastric barrier function induced by acid and accelerating repair of tissues subjected to acid in this model, suggesting that sucralfate could have utility for the treatment and prevention of SRMD in dogs.

Nutrition therapy for critically ill patients across the Asia-Pacific and Middle East regions: A consensus statement

BACKGROUND & AIMS

Guidance on managing the nutritional requirements of critically ill patients in the intensive care unit (ICU) has been issued by several international bodies. While these guidelines are consulted in ICUs across the Asia-Pacific and Middle East regions, there is little guidance available that is tailored to the unique healthcare environments and demographics across these regions. Furthermore, the lack of consistent data from randomized controlled clinical trials, reliance on expert consensus, and differing recommendations in international guidelines necessitate further expert guidance on regional best practice when providing nutrition therapy for critically ill patients in ICUs in Asia-Pacific and the Middle East.

METHODS

The Asia-Pacific and Middle East Working Group on Nutrition in the ICU has identified major areas of uncertainty in clinical practice for healthcare professionals providing nutrition therapy in Asia-Pacific and the Middle East and developed a series of consensus statements to guide nutrition therapy in the ICU in these regions.

RESULTS

Accordingly, consensus statements have been provided on nutrition risk assessment and parenteral and enteral feeding strategies in the ICU, monitoring adequacy of, and tolerance to, nutrition in the ICU and institutional processes for nutrition therapy in the ICU. Furthermore, the Working Group has noted areas requiring additional research, including the most appropriate use of hypocaloric feeding in the ICU.

CONCLUSIONS

The objective of the Working Group in formulating these statements is to guide healthcare professionals in practicing appropriate clinical nutrition in the ICU, with a focus on improving quality of care, which will translate into improved patient outcomes.

In Search of the Ideal Promotility Agent: Optimal Use of Currently Available Promotility Agents for Nutrition Therapy of the Critically Ill Patient

PURPOSE OF REVIEW

Enteral nutrition therapy is essential in the management of critically ill patients. Prokinetic agents have been used successfully to aid in the delivery of nutrition and improve feeding tolerance in patients in the intensive care unit (ICU). The aim of this report is to review the existing promotility agents available for use in the critically ill as well as outline the role of potential investigative drugs in order to provide a guide to the management of this difficult and important clinical dilemma.

RECENT FINDINGS

While no single currently available agent currently meets all of the desired goals in the critical care setting, there are an increasing number of available agents from which to choose including motilin receptor agonists, 5HT4 receptor agonists, D2 receptor antagonists, and Mu opioid receptor antagonists. We recommend a multifaceted approach to optimizing enteral nutrition in the critical care setting which should include the early, prophylactic use of promotility agents and should focus on the management of reversible causes of impaired gastrointestinal motility.

Clinical nutrition and gastrointestinal dysfunction in critically ill stroke patients

Background Data on the epidemiology and risk factors of altered gastrointestinal motility (AGIM) is virtually lacking for patients suffering from non-traumatic neurologic diseases and stroke. This study investigated whether patterns of AGIM differ between patients with stroke and other severe acute brain diseases. Methods Clinical records of stroke and non-stroke patients treated at a neurological intensive care unit (ICU) were reviewed at day 1-5 and at day 10 after admission. The data was analyzed for the course of enteral/parenteral nutrition and for and for signs and symptoms of gastrointestinal dysfunction. The study included data of 76 patients, 57 with stroke (stroke group, SG) and 19 with other neurological diseases (non-stroke group, NSG). Results Basic demographic as well as clinical baseline characteristics and alimentation regime were similar in both groups. At least one sign of AGIM was seen in 33/57 (58%) SG and in 15/19 (79%) NSG patients (P = 0.099). Regurgitation was significantly more frequent among patients from the NSG (P < 0.05). Subjects from the NSG also spent a higher proportion of time with at least one symptom of AGIM present (P < 0.05). Conclusions For the first time, this study investigated the prevalence of AGIM in patients suffering from severe stroke. The prevalence of disturbed gastrointestinal function was found to be high in stroke patients, but was lower than in a group of non-stroke patients with similar general disease severity and baseline characteristics.

Effect of Intravenous Fluids and Analgesia on Dysmotility in Patients With Acute Pancreatitis: A Prospective Cohort Study

OBJECTIVES

Analgesia and intravenous fluid resuscitation are cornerstones of initial patient management in acute pancreatitis (AP). The aim was to investigate the effect of intravenous fluids and analgesia on gastrointestinal motility in the early course of AP.

METHODS

Gastrointestinal dysmotility was assessed using the Gastroparesis Cardinal Symptom Index (GCSI). One-way analysis of variance and analysis of covariance were conducted, adjusting for age, sex, body mass index, severity of AP, preexisting diabetes mellitus, and time from first symptom onset to hospital admission.

RESULTS

A total of 108 patients with AP were prospectively enrolled. Opioid analgesia, when compared with nonopioid analgesia, was significantly associated with increase in total GCSI score in both unadjusted and adjusted analyses. There was no significant difference between aggressive and nonaggressive fluid resuscitation in both unadjusted and adjusted analyses. A combination of opioids and any intravenous fluids was associated with a significantly increased total GCSI score compared with opioids and no intravenous fluids in both unadjusted and adjusted analyses. Duration of symptoms was the confounder that significantly affected 6 of 9 studied associations.

CONCLUSIONS

Intravenous fluids and analgesia significantly affect motility independent of severity and other covariates. Guidelines on prudent use of opioids and fluids in AP need to be developed, particularly taking into account duration of symptoms from onset to hospitalization.

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.

Phenytoin inhibits contractions of rat gastrointestinal and portal vein smooth muscle by inhibiting calcium entry

BACKGROUND

Phenytoin is widely used as a second-line treatment for status epilepticus. Besides its well-known cardiac pro-arrhythmogenicity, side effects on other organ systems have received less attention.

METHODS

This study investigates the effects of phenytoin on gastrointestinal tissue function using an in vitro model of smooth muscle preparations from rats by combining registrations of pharmacological effects on mechanical contractions, electric field potentials, and dynamic intravital fluorescence microscopy.

KEY RESULTS

When added to the bathing solution at a concentration of 30 μM, phenytoin reduced the frequency of spontaneous activity significantly in antrum and portal vein preparations to 72.2 ± 36.5% (p = 0.022) and 80.7 ± 24.4% (p = 0.037) of control values, respectively. At a concentration of 100 μM, the height of spontaneous contractions declined to 9.8 ± 19.6% (p = 0.005) (antrum), 15.7 ± 28.2% (p = 0.004) (portal vein), and 31.8 ± 31.3% (p = 0.005) (colon) in comparison to the control conditions before the application of phenytoin. Depolarization triggered increases in calcium dependent fluorescence signals were reduced by 52.8 ± 39.1% (p = 0.012) The inhibition of spontaneous activity caused by phenytoin was reduced in the presence of the L-type calcium channel agonist BAY K8644(-).

CONCLUSIONS & INFERENCES

Phenytoin exerts strong inhibitory effects on the spontaneous and stimulated contractile activity of smooth muscles from both the upper and lower gastrointestinal tract. The mechanism underlying this effect is not related to the sodium channel blocking activity of phenytoin, but is rather caused by an inhibition of calcium entry through voltage dependent L-type calcium channels. The results of this study should raise vigilance to gastrointestinal complications in patients treated with phenytoin.

Nitric oxide-mediated injury of interstitial cells of Cajal and intestinal dysmotility under endotoxemia of mice

Gastrointestinal dysmotility is frequently observed under septic conditions, yet its precise mechanisms remain to be elucidated. In this study, we have investigated the mechanisms of intestinal dysmotility by lipopolysaccharides (LPS) and the role of the interstitial cells of Cajal (ICCs) in motility disorders using a mouse endotoxin model. The injection of LPS caused time- and dose-dependent decreases in the intestinal contractility, which was associated with similar time- and dose-dependent decreases in the number of KIT-positive fibroblast-like cells located in the intermuscular layer. iNOS inhibitors, L-NAME and aminoguanidine (AG), but not 7-nitroindazole (7NI), a specific nNOS inhibitor, inhibited the LPS-induced decreases in both the contractility and the number of KIT-positive cells. A spontaneous NO releaser, FK409, not only diminished spontaneous electrical potential and phasic contractions, but also decreased the number of KIT-positive cells. Pretreatment with gadolinium inhibited the activation of macrophages and the induction of iNOS in intestinal resident macrophages, and restored the number of KIT-positive cells and intestinal contractions. These results suggested that NO produced from intestinal macrophages via iNOS induced by LPS, may be involved in the ICCs injury and intestinal dysmotility under septic conditions.

Stress-related mucosal disease in the critically ill patient

Bleeding from stress-related mucosal disease in critically ill patients remains an important clinical management issue. Although only a small proportion (1-6%) of patients admitted to an intensive care unit (ICU) will bleed, a substantial proportion exhibit clinical risk factors (mechanical ventilation for >48 h and a coagulopathy) that predict an increased risk of bleeding. Furthermore, upper gastrointestinal mucosal lesions can be found in 75-100% of patients in ICUs. Although uncommon, stress-ulcer bleeding is a severe complication with an estimated mortality of 40-50%, mostly from decompensating an underlying condition or multiorgan failure. Although the vast majority of patients in ICUs receive stress-ulcer prophylaxis, largely with PPIs, some controversy surrounds their efficacy and safety. Indeed, no single trial has shown that stress-ulcer prophylaxis reduces mortality. Some reports suggest that the use of PPIs increases the risk of nosocomial infections. However, several meta-analyses and cost-effectiveness studies suggest PPIs to be more clinically effective and cost-effective than histamine-2 receptor antagonists, without considerable increases in nosocomial pneumonia. To help clinicians use the most appropriate strategy for treatment of patients in the ICU, this Review presents the latest information on all aspects of stress-related mucosal disease.

Non-anti-infective effects of antimicrobials and their clinical applications: a review

Antimicrobial agents are undoubtedly one of the key advances in the history of modern medicine and infectious diseases, improving the clinical outcomes of infection owing to their inhibitory effects on microbial growth. However, many antimicrobial agents also have biological activities stemming from their interactions with host receptors and effects on host inflammatory responses and other human or bacterial cellular biological pathways. These result in clinical uses of antimicrobial drugs that are distinct from their direct bacteriostatic or bactericidal properties. We reviewed the published literature regarding non-anti-infective therapeutic properties and proposed clinical applications of selected antimicrobials, specifically, macrolides, tetracyclines, sulfonamides, and ketoconazole. The clinical applications reviewed were varied, and we focused on uses that were clinically relevant (in terms of importance and burden of disease) and where published evidence exists. Such uses include chronic inflammatory pulmonary and skin disorders, chronic periodontitis, gastrointestinal dysmotility, rheumatoid arthritis, and cancer. Most of these potential therapeutic uses are not Food and Drug Administration approved. Clinicians need to weigh the use of antimicrobial agents for their non-anti-infective benefits, considering potential adverse effects and long-term effect on microbial resistance.

Value of acute gastrointestinal injury grading system in assessing gastrointestinal dysfunction in critically ill patients: Application in early enteral nutrition

AIM: To investigate the value of acute gastrointestinal injury (AGI) grading system in assessing gastrointestinal dysfunction in critically ill patients and to assess its application in early enteral nutrition (EN).

METHODS: Seventy-eight patients with gastrointestinal dysfunction admitted to intensive care unit (ICU) from January 2013 to January 2014 were divided into different groups using the AGI grading system: gradeⅠ(35 cases), grade Ⅱ (22 cases), grade Ⅲ (12 cases), and grade Ⅳ (9 cases). The patients were given appropriate treatment based on the AGI guideline. The nutritional status before and after EN implementation, severity, rate of adequate intake, changes in the function of the gastrointestinal mucosa were compared between the two groups. The relationship between AGI grading and EN feeding rate and rate of adequate calories was also analyzed.

RESULTS: The levels of APACHE Ⅱ score, serum albumin (ALB), nitrogen balance (NB), total protein (TP), gastric pH, lactate, and PgCO₂ showed no significant differences among the four groups before treatment (P > 0.05); after 7 d of treatment, the APACHE Ⅱ score, lactate, and PgCO₂ significantly decreased (P < 0.05), and the levels of ALB, NB, TP, and pH value significantly increased in grades Ⅰ-Ⅲ groups (P < 0.05). The APACHE Ⅱ score, lactate, and PgCO₂ were significantly higher (P < 0.05), and the values ​​of NB, TP, and pH before treatment were significantly lower in grade Ⅳ group than in grades Ⅰ-Ⅲ groups (P < 0.05), although the level of ALB showed no significant difference among the four groups (P > 0.05). The 4-h feeding rates in grades Ⅰ-Ⅳ groups were 91.43%, 68.18%, 50.00%, and 0.00%, respectively, and the 48-h feeding rates were 100.00%, 81.82%, 58.33%, and 0.00%. The 7-d rate of adequate calories in grades Ⅰ-Ⅳ groups were 100.00%, 81.82%, 66.67% and 22.22%, respectively.

CONCLUSION: AGI grading has a good correlation with EN treatment and can be used for gastrointestinal function evaluation in critically ill patients.

The effect of fibers on coagulation of casein-based enteral nutrition in an artificial gastric digestion model

A serious complication seen in critically ill patients is the solidification of enteral nutrition causing gastrointestinal obstruction.

A novel protein mixture containing vegetable proteins renders enteral nutrition products non-coagulating after in vitro gastric digestion

BACKGROUND & AIMS

Non-coagulation of protein from enteral nutrition (EN) in the stomach is considered to improve gastric emptying and may result in reduced upper gastrointestinal complications such as reflux and aspiration pneumonia. For the development of a new EN protein mixture with reduced gastric coagulation, the coagulating properties of individual proteins, a novel blend of four proteins (P4 protein blend) and commercial EN products were investigated.

METHODS

A semi-dynamic, computer controlled setup was developed to mimic gastric digestion. The coagulation behaviour of 150 ml protein solutions and EN products was investigated. These were heat-treated calcium caseinate, sodium caseinate, whey, soy and pea protein, and the P4 protein blend comprising of the latter four (all solutions 6% w/v protein), four new enteral nutrition product varieties (New Nutrison® .0 or 1.5 kcal/ml, with and without MultiFibre MF6™) based on the P4 protein blend and two other commercially available casein dominant EN products (T1 and T2).

RESULTS

Calcium caseinate and sodium caseinate yielded a total wet coagulate of 43.5 ± 0.7 g and 52.7 ± 6.2 g, respectively. Whey, soy, pea and the P4 protein blend did not produce any measurable coagulate. T1 and T2 resulted in a total wet coagulate of 37.5 ± 0.8 g and 57.3 ± 0.8 g, respectively, while all new EN product varieties based on the P4 protein blend did not produce any measurable coagulate.

CONCLUSIONS

The P4 protein blend renders EN product varieties non-coagulating after in vitro gastric digestion.