Clonidine reduces diarrhea and sodium loss in patients with proximal jejunostomy: a controlled study

Clinical management of high-output stoma: a systematic literature review and meta-analysis

PURPOSE

High output is a common complication after stoma formation. Although the management of high output is described in the literature, there is a lack of consensus on definitions and treatment. Our aim was to review and summarise the current best evidence.

METHODS

MEDLINE, Cochrane Library, BNI, CINAHL, EMBASE, EMCARE, and ClinicalTrials.gov were searched from 1 Jan 2000 to 31 Dec 2021 for relevant articles on adult patients with a high-output stoma. Patients with enteroatmospheric fistulas and case series/reports were excluded. Risk of bias was assessed using RoB2 and MINORS. The review was registered in PROSPERO (CRD42021226621).

RESULTS

The search strategy identified 1095 articles, of which 32 studies with 768 patients met the inclusion criteria. These studies comprised 15 randomised controlled trials, 13 non-randomised prospective trials, and 4 retrospective cohort studies. Eighteen different interventions were assessed. In the meta-analysis, there was no difference in stoma output between controls and somatostatin analogues (g - 1.72, 95% CI - 4.09 to 0.65, p = 0.11, I2 = 88%, t2 = 3.09), loperamide (g - 0.34, 95% CI - 0.69 to 0.01, p = 0.05, I2 = 0%, t2 = 0) and omeprazole (g - 0.31, 95% CI  - 2.46 to 1.84, p = 0.32, I2 = 0%, t2 = 0). Thirteen randomised trials showed high concern of bias, one some concern, and one low concern. The non-randomised/retrospective trials had a median MINORS score of 12 out of 24 (range 7-17).

CONCLUSION

There is limited high-quality evidence favouring any specific widely used drug over the others in the management of high-output stoma. Evidence, however, is weak due to inconsistent definitions, risk of bias and poor methodology in the existing studies. We recommend the development of validated core descriptor and outcomes sets, as well as patient-reported outcome measures.

ESPEN guideline on chronic intestinal failure in adults - Update 2023

BACKGROUND & AIMS

In 2016, ESPEN published the guideline for Chronic Intestinal Failure (CIF) in adults. An updated version of ESPEN guidelines on CIF due to benign disease in adults was devised in order to incorporate new evidence since the publication of the previous ESPEN guidelines.

METHODS

The grading system of the Scottish Intercollegiate Guidelines Network (SIGN) was used to grade the literature. Recommendations were graded according to the levels of evidence available as A (strong), B (conditional), 0 (weak) and Good practice points (GPP). The recommendations of the 2016 guideline (graded using the GRADE system) which were still valid, because no studies supporting an update were retrieved, were reworded and re-graded accordingly.

RESULTS

The recommendations of the 2016 guideline were reviewed, particularly focusing on definitions, and new chapters were included to devise recommendations on IF centers, chronic enterocutaneous fistulas, costs of IF, caring for CIF patients during pregnancy, transition of patients from pediatric to adult centers. The new guideline consist of 149 recommendations and 16 statements which were voted for consensus by ESPEN members, online in July 2022 and at conference during the annual Congress in September 2022. The Grade of recommendation is GPP for 96 (64.4%) of the recommendations, 0 for 29 (19.5%), B for 19 (12.7%), and A for only five (3.4%). The grade of consensus is "strong consensus" for 148 (99.3%) and "consensus" for one (0.7%) recommendation. The grade of consensus for the statements is "strong consensus" for 14 (87.5%) and "consensus" for two (12.5%).

CONCLUSIONS

It is confirmed that CIF management requires complex technologies, multidisciplinary and multiprofessional activity, and expertise to care for the underlying gastrointestinal disease and to provide HPN support. Most of the recommendations were graded as GPP, but almost all received a strong consensus.

Congenital sodium diarrhoea caused by rare de novo activating guanylate cyclase mutation

A male infant with prenatal history significant for polyhydramnios requiring multiple amnioreductions with suspicion of small bowel atresia was born at 31 weeks 5 days' gestation with abdominal distension. He underwent three exploratory laparotomies and ileostomy for small bowel obstruction and was found to have fluid-filled intestinal dilatation. Serum and stool chemistries suggested sodium secretory diarrhoea. A rapid whole-exome sequencing confirmed de novo guanylate cyclase mutation variant as a cause for his congenital sodium secretory diarrhoea. He required large volume of fluid and electrolyte replacement along with total parenteral nutrition. Several medications to restore normal sodium homeostasis by targeting molecular mechanisms and pathogenesis described in previous literature failed to decrease stool output and electrolyte loss. He was discharged home at 11 months of age on total parenteral nutrition and weekly iron therapy.

Short Bowel Syndrome in Adults

Short bowel syndrome (SBS) is a rare disorder characterized by severe intestinal dysfunction leading to malabsorption of macronutrients and micronutrients that often results in permanent need of parenteral nutrition support. Patients can develop SBS because of massive intestinal resection or loss of intestinal function and consequently experience significant morbidity and increased healthcare utilization. The remaining anatomy and length of bowel after intestinal resection have important prognostic and therapeutic implications. Because patients with SBS constitute a heterogenous group, management is complex and multifaceted, involving nutrition support, fluid and electrolyte management, and pharmacologic therapies in particular to control diarrhea. Surgical interventions including intestinal transplantation may be considered in selected individuals. Successful care of these patients is best accomplished by a multidisciplinary team that is experienced in the management of this syndrome.

Small and Large Intestine (II): Inflammatory Bowel Disease, Short Bowel Syndrome, and Malignant Tumors of the Digestive Tract

The small intestine is key in the digestion and absorption of macro and micronutrients. The large intestine is essential for the absorption of water, to allow adequate defecation, and to harbor intestinal microbiota, for which their nutritional role is as important as it is unknown. This article will describe the causes and consequences of malnutrition in patients with inflammatory bowel diseases, the importance of screening and replacement of micronutrient deficits, and the main indications for enteral and parenteral nutrition in these patients. We will also discuss the causes of short bowel syndrome, a complex entity due to anatomical or functional loss of part of the small bowel, which can cause insufficient absorption of liquid, electrolytes, and nutrients and lead to complex management. Finally, we will review the causes, consequences, and management of malnutrition in patients with malignant and benign digestive tumors, including neuroendocrine tumors (present not only in the intestine but also in the pancreas).

Chronic intestinal failure and short bowel syndrome in Crohn’s disease

Chronic intestinal failure (CIF) is a rare but feared complication of Crohn’s disease. Depending on the remaining length of the small intestine, the affected intestinal segment, and the residual bowel function, CIF can result in a wide spectrum of symptoms, from single micronutrient malabsorption to complete intestinal failure. Management of CIF has improved significantly in recent years. Advances in home-based parenteral nutrition, in particular, have translated into increased survival and improved quality of life. Nevertheless, 60% of patients are permanently reliant on parenteral nutrition. Encouraging results with new drugs such as teduglutide have added a new dimension to CIF therapy. The outcomes of patients with CIF could be greatly improved by more effective prevention, understanding, and treatment. In complex cases, the care of patients with CIF requires a multidisciplinary approach involving not only physicians but also dietitians and nurses to provide optimal intestinal rehabilitation, nutritional support, and an improved quality of life. Here, we summarize current literature on CIF and short bowel syndrome, encompassing epidemiology, pathophysiology, and advances in surgical and medical management, and elucidate advances in the understanding and therapy of CIF-related complications such as catheter-related bloodstream infections and intestinal failure-associated liver disease.

The safety of available treatment options for short bowel syndrome and unmet needs

INTRODUCTION

Short bowel syndrome (SBS) is a rare, highly disabling, life-threatening condition due to extensive intestinal resections, characterized by diarrhea, malabsorption, and malnutrition. SBS is the main cause of intestinal failure (SBS-IF). The primary therapy for SBS-IF is intravenous supplementation (IVS) of nutrients. The pharmacological therapy aims to improve the remnant bowel function, leading to the decrease of IVS requirement.

AREAS COVERED

This review provides a safety perspective and discusses unmet clinical needs on pharmacotherapy for SBS, ranging from symptomatic agents traditionally used off-label to manage hypersecretion and diarrhea, to curative drugs with selective intestinotrophic properties. Real-world evidence on symptomatic drugs is lacking. Data on teduglutide - the first-in-class glucagon-like peptide-2 (GLP-2) receptor agonist approved in SBS - are mainly derived from clinical trials, with several unsettled safety issues, including the risk of malignancies.

EXPERT OPINION

Defining the long-term safety of drugs used for SBS is a priority; a unified list of commonly used drugs with consolidated proof of effectiveness is needed to harmonize the symptomatic pharmacological approach to SBS. GLP-2 receptor agonists are a promising curative pharmaco-therapeutic approach, although long-term safety and effectiveness deserve further real-world assessment. Pharmacovigilance and global data sharing are crucial to support safe prescribing in SBS.

How to manage a high-output stoma

A high-output stoma (HOS) or fistula is when small bowel output causes water, sodium and often magnesium depletion. This tends to occur when the output is >1.5 -2.0 L/24 hours though varies according to the amount of food/drink taken orally. An HOS occurs in up to 31% of small bowel stomas. A high-output enterocutaneous fistula may, if from the proximal small bowel, behave in the same way and its fluid management will be the same as for an HOS. The clinical assessment consists of excluding causes other than a short bowel and treating them (especially partial or intermittent obstruction). A contrast follow through study gives an approximate measurement of residual small intestinal length (if not known from surgery) and may show the quality of the remaining small bowel. If HOS is due to a short bowel, the first step is to rehydrate the patient so stopping severe thirst. When thirst has resolved and renal function returned to normal, oral hypotonic fluid is restricted and a glucose-saline solution is sipped. Medication to slow transit (loperamide often in high dose) or to reduce secretions (omeprazole for gastric acid) may be helpful. Subcutaneous fluid (usually saline with added magnesium) may be given before intravenous fluids though can take 10-12 hours to infuse. Generally parenteral support is needed when less than 100 cm of functioning jejunum remains. If there is defunctioned bowel in situ, consideration should be given to bringing it back into continuity.

Weaning from Parenteral Nutrition

The ultimate goal of treatment of short bowel syndrome/intestinal failure patients is to achieve enteral autonomy by eliminating parenteral nutrition (PN)/intravenous fluids (IV). After optimization of diet, oral hydration and anti-diarrheal medications, attempt should be made to eliminate PN/IV. Weaning from PN/IV should be individualized for each patient. Although teduglutide is the preferred agent for PN/IV volume reduction or successful weaning, optimal patient selection and long-term safety need further evaluation. Following PN/IV elimination, patients need long-term monitoring for nutritional deficiencies. This article will address clinical considerations before, during, and after PN/IV weaning to facilitate safe and successful PN/IV weaning process.

Minimizing opioid use after acute major trauma

PURPOSE

Results of an initiative at an academic medical center to reduce prescription opioid use in patients with acute traumatic injuries are reported.

METHODS

In 2014, the University of Kentucky Hospital trauma service implemented a pain management strategy consisting of patient and provider education emphasizing the use of nonopioid analgesics to minimize opioid use without compromising analgesia effectiveness. To assess the impact of the initiative, a retrospective analysis of data on cohorts of patients admitted with acute trauma before (n = 489) and after (n = 424) project implementation was conducted. The primary endpoint was opioid use (prescribed daily milligram morphine equivalents [MME]) at discharge. Secondary endpoints included inpatient opioid and alternative analgesic use, pain control, ileus development, length of stay, and discharge disposition.

RESULTS

Compared with the preintervention cohort, the postintervention cohort had a lower median daily discharge MME overall (45 MME versus 90 MME, p < 0.001); after stratification of MME data by baseline opioid use, this finding held true only for patients with no opioid prescription at admission. Although utilization of gabapentinoids, skeletal muscle relaxants, and clonidine increased during the postintervention period, inpatient opioid use did not differ significantly in the 2 cohorts. Utilization of both nonsteroidal antiinflammatory drugs and acetaminophen was lower in the postintervention cohort versus the preintervention cohort.

CONCLUSION

Targeted provider and patient education on minimizing opioid use was associated with a reduction in MME on discharge from the hospital after traumatic injury.

Intestinal Failure and Rehabilitation

The rendering of proper care for the patient with intestinal failure requires the provider to have a functional understanding of digestion and absorption, nutrient requirements, and intestinal adaptation. Inherent in those concepts is that not only is nutritional absorption compromised, but medication absorption is as well. The principles of the management of home parenteral nutrition must be mastered and then proper and controlled weaning of parenteral nutrition may be commenced by use of dietary and pharmacologic means with appropriate clinical outcome measures followed. This complicated management requires a team experienced in both medical and surgical management of intestinal failure.

Systematic review: pharmacotherapy for high-output enterostomies or enteral fistulas

BACKGROUND

High-output enterocutaneous fistula or enterostomies can cause intestinal failure. There is a wide variety of options in medical management of patients with high output.

AIM

To systematically review the literature on available pharmacotherapy to reduce output and to propose an algorithm for standard of care.

METHODS

Relevant databases were systematically reviewed to identify studies on pharmacotherapy for reduction in (high-) output enterostomies or fistula. Randomised controlled trials and within subjects controlled prospective trials were included. An algorithm for standard of care was generated based on the outcomes of the systematic review.

RESULTS

Two studies on proton pump inhibitors, six on anti-motility agents, three on histamine receptor antagonists, one on an α2- receptor agonist and eight on somatostatin (analogues) were included. One study examined a proton pump inhibitor and a histamine receptor antagonist within the same patients. Overall, we found evidence for the following medical therapies to be effective: omeprazole, loperamide and codeine, ranitidine and cimetidine. On the basis of these outcomes and clinical experience, we proposed an algorithm for standard of care which consists of high-dose proton pump inhibitors combined with high-dose loperamide as the first step followed by addition of codeine in case of insufficient output reduction. So far, there is insufficient evidence for the standard use of somatostatin (analogues).

CONCLUSIONS

The available evidence on the efficacy of medication to reduce enterostomy or enterocutaneous fistula output is hampered by low quality studies. We propose an algorithm for standard of care output reduction in these patients.

Management and Complications of Short Bowel Syndrome: an Updated Review

Short bowel syndrome (SBS) is defined as loss of bowel mass from surgical resection, congenital defects, or disease. Intestinal failure (IF) includes the subset of SBS unable to meet nutrition needs with enteral supplements and requires parenteral nutrition (PN). The parenteral treatment of SBS is now a half-century old. Recent pharmacologic treatment (GLP-2 analogues) has begun to make a significant impact in the care and ultimate management of these patients such that the possibility of reducing PN requirements in formerly PN-dependent patients is a now a real possibility. Finally, newer understanding and possible treatment for some of the complications related to IF have more recently evolved and will be an emphasis of this report. This review will focus on developments over the last 10 years with the goal of updating the reader to new advances in our understanding of the care and feeding of the SBS patient.

What about clonidine for diarrhoea? A systematic review and meta-analysis of its effect in humans

BACKGROUND

Clonidine is considered an alternative treatment for refractory diarrhoea. The evidence in the literature is scarce and not conclusive. The present paper's purpose is to gather available evidence and provide a systematic answer regarding the effectiveness of clonidine for diarrhoea.

METHOD

We performed a systematic review of clonidine and its effect on diarrhoea. Meta-analysis was performed with a random effects model of the standardized mean difference (SMD) or the weighted mean difference and heterogeneity was quantified with I (2) and publication bias was assessed with Egger's and Begg's test. Subgroup analyses and meta-regression were performed to investigate sources of heterogeneity. Any empirical study describing use of clonidine for diarrhoea in humans independent of age was included. For the meta-analysis, papers had to provide sufficient data to produce an effect measure, while case reports were not included in the meta-analysis and are discussed narratively only.

RESULTS

A total of 24 trials and seven case reports were identified. Clonidine (median dose 300 μg/day) has been used for treatment of diarrhoea in irritable bowel syndrome, faecal incontinence, diabetes, withdrawal-associated diarrhoea, intestinal failure, neuroendocrine tumours and cholera; studies were also performed on healthy volunteers. Results indicate a strong effect of clonidine on diarrhoea (SMD = -1.02, 95% confidence interval [CI] -1.46 to -0.58) with a decrease of stool volume by 0.97 l/day, stool frequency by 0.4 times/day and increase in transit time by 31 minutes. In a sensitivity analysis of studies with functional diarrhoea and sample size over 10 subjects, the effect was similar -0.99 (95% CI -1.54 to -0.43). There is however significant heterogeneity and publication bias. Heterogeneity decreased in subgroup analyses by condition but not with other factors examined. A limitation of the present study includes small study effects.

CONCLUSION

Clonidine is effective for treatment of diarrhoea and should be considered as an alternative when all other medications have failed.

Promoting intestinal adaptation by nutrition and medication

The ultimate goal in the treatment of short bowel syndrome is to wean patients off parenteral nutrition, by promoting intestinal adaptation. Intestinal adaptation is the natural compensatory process that occurs after small bowel resection. Stimulating the remaining bowel with enteral nutrition can enhance this process. Additionally, medication can be used to either reduce factors that complicate the adaptation process or to stimulate intestinal adaptation, such as antisecretory drugs and several growth factors. The aim of this review was to provide an overview of the best nutritional strategies and medication that best promote intestinal adaptation.

ESPEN guidelines on chronic intestinal failure in adults

BACKGROUND & AIMS

Chronic Intestinal Failure (CIF) is the long-lasting reduction of gut function, below the minimum necessary for the absorption of macronutrients and/or water and electrolytes, such that intravenous supplementation is required to maintain health and/or growth. CIF is the rarest organ failure. Home parenteral nutrition (HPN) is the primary treatment for CIF. No guidelines (GLs) have been developed that address the global management of CIF. These GLs have been devised to generate comprehensive recommendations for safe and effective management of adult patients with CIF.

METHODS

The GLs were developed by the Home Artificial Nutrition & Chronic Intestinal Failure Special Interest Group of ESPEN. The GRADE system was used for assigning strength of evidence. Recommendations were discussed, submitted to Delphi rounds, and accepted in an online survey of ESPEN members.

RESULTS

The following topics were addressed: management of HPN; parenteral nutrition formulation; intestinal rehabilitation, medical therapies, and non-transplant surgery, for short bowel syndrome, chronic intestinal pseudo-obstruction, and radiation enteritis; intestinal transplantation; prevention/treatment of CVC-related infection, CVC-related occlusion/thrombosis; intestinal failure-associated liver disease, gallbladder sludge and stones, renal failure and metabolic bone disease. Literature search provided 623 full papers. Only 12% were controlled studies or meta-analyses. A total of 112 recommendations are given: grade of evidence, very low for 51%, low for 39%, moderate for 8%, and high for 2%; strength of recommendation: strong for 63%, weak for 37%.

CONCLUSIONS

CIF management requires complex technologies, multidisciplinary and multiprofessional activity, and expertise to care for both the underlying gastrointestinal disease and to provide HPN support. The rarity of the condition impairs the development of RCTs. As a consequence, most of the recommendations have a low or very low grade of evidence. However, two-thirds of the recommendations are considered strong. Specialized management and organization underpin these recommendations.

The pharmacologic treatment of short bowel syndrome: new tricks and novel agents

Short bowel syndrome (SBS) is a manifestation of massive resection of the intestines resulting in severe fluid, electrolyte, and vitamin/mineral deficiencies. Diet and parenteral nutrition play a large role in the management of SBS; however, pharmacologic options are becoming more readily available. These pharmacologic agents focus on reducing secretions and stimulating intestinal adaptation. The choice of medication is highly dependent on the patient's symptoms, remaining anatomy, and risk versus benefit profile for each agent. This article focuses on common and novel pharmacologic medications used in SBS, including expert advice on their indications and use.

Pharmacologic management of diarrhea in patients with short bowel syndrome

Diarrhea associated with short bowel syndrome (SBS) can have multiple etiologies, including accelerated intestinal transit, gastric acid hypersecretion, intestinal bacterial overgrowth, and malabsorption of fats and bile salts. As a result, patients may need multiple medications to effectively control fecal output. The armamentarium of antidiarrheal drugs includes antimotility agents, antisecretory drugs, antibiotics and probiotics, bile acid-binding resins, and pancreatic enzymes. An antidiarrheal regimen must be individualized for each patient and should be developed using a methodical, stepwise approach. Treatment should be initiated with a single first-line medication at the low end of its dosing range. Dosage and/or dosing frequency can then be slowly escalated to achieve maximal effect while minimizing adverse events. If diarrhea remains poorly controlled, additional agents can be incorporated sequentially. If modification of the regimen is required, a single medication should be altered or exchanged at a time. After each adjustment of the regimen, sufficient time should be permitted to fully assess response (≥3-5 days) before initiating additional changes. SBS-associated malabsorption is a major obstacle to optimization of an antidiarrheal regimen because drug absorption is impaired. Patients may benefit from high dosages and/or frequent dosing intervals, liquid preparations, or nonoral routes of drug delivery. Although the diarrhea associated with SBS can be debilitating, effective pharmaceutical management has the potential to substantially improve health outcomes and quality of life for these patients.

An overview of short bowel syndrome management: adherence, adaptation, and practical recommendations

Short bowel syndrome (SBS) refers to the clinical consequences resulting from loss of small bowel absorptive surface area due to surgical resection or bypass. The syndrome is characterized by maldigestion, malabsorption, and malnutrition. Survival of patients with SBS is dependent on adaptation in the remaining bowel and a combination of pharmacologic and nutrition therapies. Individual plans of care are developed based on the length and sites of remaining bowel, the degree of intestinal adaptation, and the patient's ability to adhere to the medication and dietary regimens. Antisecretory and antidiarrheal medications are prescribed to slow intestinal transit times and optimize fluid and nutrient absorption. Based on postsurgical anatomy, enteral feedings, parenteral infusions, complex diet plans, and vitamin and mineral supplementation are used in various combinations to nourish patients with SBS. In the acute care setting, registered dietitians (RDs) assist with infusion therapy, diet education, and discharge planning. Long-term, as the small intestine adapts, RDs revise the nutrition care plan and monitor for nutrient deficiencies, metabolic bone disease, and anemia. The frequent monitoring and revision of care plans, plus the appreciable benefits from proper medical nutrition therapy, make this patient population extremely challenging and rewarding for RDs to manage. This article provides a brief, case study-based overview of the medical and nutrition management of SBS.

A review of enteral strategies in infant short bowel syndrome: evidence-based or NICU culture?

INTRODUCTION

Short bowel syndrome (SBS) is an increasingly common condition encountered across neonatal intensive care units. Improvements in parenteral nutrition (PN), neonatal intensive care and surgical techniques, in addition to an improved understanding of SBS pathophysiology, have contributed in equal parts to the survival of this fragile subset of infants. Prevention of intestinal failure associated liver disease (IFALD) and promotion of intestinal adaptation are primary goals of all involved in the care of these patients. While enteral nutritional and pharmacological strategies are necessary to achieve these goals, there remains great variability in the application of therapeutic strategies in units that are not necessarily evidence-based.

MATERIALS AND METHODS

A search of major English language medical databases (SCOPUS, Index Medicus, Medline, and the Cochrane database) was conducted for the key words short bowel syndrome, medical management, nutritional management and intestinal adaptation. All pharmacological and nutritional agents encountered in the literature search were classified based on their effects on absorptive capacity, intestinal adaptation and bowel motility that are the three major strategies employed in the management of SBS. The Oxford Center for Evidence-Based Medicine (CEBM) classification for levels of evidence was used to develop grades of clinical recommendation for each variable studied.

RESULTS

We reviewed various medications used and nutritional strategies included soluble fiber, enteral fat, glutamine, probiotics and sodium supplementation. Most interventions have scientific rationale but little evidence to support their role in the management of infant SBS. While some of these agents symptomatically improve diarrhea, they can adversely influence pancreatico-biliary function or actually impair intestinal adaptation. Surgical anatomy and liver function are two important variables that should determine the selection of pharmacological and nutritional interventions.

DISCUSSION

There is a paucity of research investigating optimal clinical practice in infant SBS and the little evidence available is consistently of lower quality, resulting in a wide variation of clinical practices among NICUs. Prospective trials should be encouraged to bridge the evidence gap between research and clinical practice to promote further progress in the field.

Critical illness, gastrointestinal complications, and medication therapy during enteral feeding in critically ill adult patients

Critically ill patients who are subjected to high stress or with severe injury can rapidly break down their body protein and energy stores. Unless adequate nutrition is provided, malnutrition and protein wasting may occur, which can negatively affect patient outcome. Enteral nutrition (EN) is the mainstay of nutrition support therapy in patients with a functional gastrointestinal (GI) tract who cannot take adequate oral nutrition. EN in critically ill patients provides the benefits of maintaining gut functionality, integrity, and immunity as well as decreasing infectious complications. However, the ability to provide timely and adequate EN to critically ill patients is often hindered by GI motility disorders and complications associated with EN. This paper reviews the GI complications and intolerances associated with EN in critically ill patients and provides recommendations for their prevention and treatment. It also addresses the role of commonly used medications in the intensive care unit and their impact on GI motility and EN delivery.

The dilated bowel: a liability and an asset

The gastrointestinal tract responds to significant mechanical or functional obstruction by dilatation and hypertrophy of the segment proximal to the obstruction. Excessive dilatation compromises motility, and absorption and is associated with considerable morbidity (intraluminal stasis, sepsis) such that bowel dilatation represents a major liability that predisposes the patient to intestinal failure. The dilated bowel proximal to an obstruction provides valuable autologous material for reconstruction with "tissue appropriate to the part." Bowel elongation and dilatation are integral to the natural intestinal adaptation response to loss of small bowel and can also be induced through a structured "Bowel Expansion" program. The additional absorptive tissue that is progressively generated is essential for reconstruction of the bowel (tailoring and lengthening), to restore gastrointestinal dynamics (effective propulsion and absorption), and to reduce morbidity (intraluminal stasis, sepsis). In enhancing the prospects for enteral autonomy, dilatation and elongation of the residual autologous bowel are crucial to long-term survival and good quality life, and represent a most welcome asset. This paper reviews the impact and management of bowel dilatation along the gastrointestinal tract.

Short bowel syndrome: searching for the proper diet

Short bowel syndrome occurs subsequent to anatomical and/or functional loss of mainly small bowel. This often-devastating disease leads to weight loss and immune dysfunction. Proper medical management involves adequate substitution and maintenance of fluid, electrolytes, and nutrients. Although several pharmacological therapies such as clonidine, growth hormone, or octreotide have shown promising results in short bowel syndrome, optimal nutritional management is the most important factor in these patients. If enteral nutrition is possible, diet should consist mainly of fat, followed by protein, and less intake of carbohydrates. Supplementary nonprocessed cereals may be beneficial in a certain subgroup of patients. With the recent developments in medical therapy, a balanced diet may allow many patients to become nutritionally autonomous.

Inter-kingdom signalling: communication between bacteria and their hosts

Microorganisms and their hosts communicate with each other through an array of hormonal signals. This cross-kingdom cell-to-cell signalling involves small molecules, such as hormones that are produced by eukaryotes and hormone-like chemicals that are produced by bacteria. Cell-to-cell signalling between bacteria, usually referred to as quorum sensing, was initially described as a means by which bacteria achieve signalling in microbial communities to coordinate gene expression within a population. Recent evidence shows, however, that quorum-sensing signalling is not restricted to bacterial cell-to-cell communication, but also allows communication between microorganisms and their hosts.

Centrally acting antihypertensive agents: an update

Centrally acting agents stimulate alpha(2) receptors and/or imadozoline receptors on adrenergic neurons situated within the rostral ventrolateral medulla and, in so doing, sympathetic outflow is reduced. Centrally acting agents also stimulate peripheral alpha(2) receptors, which, for the most part, is of marginal clinical significance. Central a agonists have had a lengthy history of use, starting with alpha-methyldopa, which has had a dramatic decline in use, in part, because of bothersome side effects. Patients who require multidrug therapy with otherwise resistant hypertension, such as diabetic and/or renal failure patients, are typically responsive to these drugs, as are patients with sympathetically driven forms of hypertension. Perioperative forms of hypertension respond well to clonidine, a circumstance where the additional anesthesia- and analgesia-sparing effects of this drug may offer additional clinical benefits. Clonidine can be used adjunctively with other more traditional therapies in heart failure, particularly when hypertension is present. Sustained-release moxonidine, however, is associated with early mortality and morbidity when used in patients with heart failure. Escalating doses of drugs in this class often give rise to salt and water retention, in which case diuretic therapy becomes a valuable adjunctive therapy.