Intestinal motility disturbances in intensive care patients pathogenesis and clinical impact

Effect of opioids on constipation in critically ill patients: A meta-analysis

OBJECTIVES

This meta-analysis evaluated the effect of opioids on constipation in ICU patients.

REVIEW METHOD USED

Systematic review and meta-analysis.

DATA SOURCES

PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure (CNKI), and Wanfang DATA databases.

REVIEW METHODS

Random or fixed-effects meta-analyses were used. Subgroup analysis was performed according to the definition of constipation (three vs. six days), opioids (fentanyl vs. morphine), study design (prospective vs. retrospective), adjustment of confounders (No vs. Yes), and patient's age (adults vs. children). We used sensitivity analysis to test the robustness of results with significant statistical heterogeneity.

RESULTS

Seven studies (2264 patients) were included. Opioid use in ICU patients was associated with an increased risk of constipation (relative risk [RR]=1.14; 95% confidence interval [CI]=1.05 to 1.24; I2=49.8%). Subgroup analysis further showed that adjustment form, category of opioid, study design, and patient's age significantly influenced the relationship between opioid use and the risk of constipation. Sensitivity analysis confirmed the robustness of pooled results.

CONCLUSION

Opioids significantly increase the risk of constipation in critically ill patients, especially children. It is worth noting that the adjustment of the constipation definition used for ICU significantly influenced the relationship between opioid use and the risk of constipation. Therefore, It is necessary to clearly define ICU constipation and conduct time-based layered treatment. Additional prospective studies are needed to investigate the consistent definition of ICU constipation.

Enteral feeding tolerance during pharmacologic neuromuscular blockade

A common misperception is that critically ill patients who receive paralytic therapy will not tolerate enteral nutrition. As a result, some clinicians empirically withhold enteral feedings for critically ill patients who receive neuromuscular blocker pharmacotherapy (NMB). The intent of this review is to examine the evidence regarding enteral feeding tolerance for critically ill patients given NMB. Studies evaluating enteral feeding during paralytic therapy are provided and critiqued. Evidence examining enteral feeding tolerance during NMB is limited. Enteral feeding intolerance is more likely attributable to the underlying illnesses and concurrent opioid analgesia, sedation, and vasopressor therapies. Most critically ill patients can be successfully fed during NMB. Prokinetic pharmacotherapy may be warranted in some patients.

Oral Drug Absorption and Drug Disposition in Critically Ill Cardiac Patients

(1) Background: In critically ill cardiac patients, parenteral and enteral food and drug administration routes may be used. However, it is not well known how drug absorption and metabolism are altered in this group of adult patients. Here, we analyze drug absorption and metabolism in patients after cardiogenic shock using the pharmacokinetics of therapeutically indicated esomeprazole. (2) Methods: The pharmacokinetics of esomeprazole were analyzed in a consecutive series of patients with cardiogenic shock and controls before and after elective cardiac surgery. Esomeprazole was administered orally or with a nasogastric tube and once as an intravenous infusion. (3) Results: The maximum plasma concentration and AUC of esomeprazole were, on average, only half in critically ill patients compared with controls (p < 0.005) and remained lower even seven days later. Interestingly, esomeprazole absorption was also markedly compromised on day 1 after elective surgery. The metabolites of esomeprazole showed a high variability between patients. The esomeprazole sulfone/esomeprazole ratio reflecting CYP3A4 activity was significantly lower in critically ill patients even up to day 7, and this ratio was negatively correlated with CRP values (p = 0.002). The 5'-OH-esomeprazole and 5-O-desmethyl-esomeprazol ratios reflecting CYP2C19 activity did not differ significantly between critically ill and control patients. (4) Conclusions: Gastrointestinal drug absorption can be significantly reduced in critically ill cardiac patients compared with elective patients with stable cardiovascular disease. The decrease in bioavailability indicates that, under these conditions, any vital medication should be administered intravenously to maintain high levels of medications. After shock, hepatic metabolism via the CYP3A4 enzyme may be reduced.

Gut Microbiota and Critically Ill Patients: Immunity and Its Modulation via Probiotics and Immunonutrition

Critically ill patients have a hyper-inflammatory response against various offending injuries that can result in tissue damage, organ failure, and fatal prognosis. The origin of this detrimental, uncontrolled inflammatory cascade can be found also within our gut. In detail, one of the main actors is our gut microbiota with its imbalance, namely gut dysbiosis: learning about the microbiota's dysfunction and pathophysiology in the frame of critical patients is of crucial and emerging importance in the management of the systemic inflammatory response syndrome (SIRS) and the multiple organ dysfunction syndrome (MODS). Multiple pieces of evidence indicate that the bacteria that populate our gut efficiently modulate the immune response. Treatment and pretreatment with probiotics have shown promising preliminary results to attenuate systemic inflammation, especially in postoperative infections and ventilation performance. Finally, it is emerging how immunonutrition may exert a possible impact on the health status of patients in intensive care. Thus, this manuscript reviews evidence from the literature on gut microbiota composition, its derangement in critically ill patients, its pathophysiological role, and the described and emerging opportunities arising from its modulation.

The Effect of Abdominal Massage on Discharge and Ventilator-Associated Pneumonia in Enterally Fed Patients Connected to Mechanical Ventilation: A Randomized Controlled Study

PURPOSE

The present research was conducted to reveal the impact of abdominal massage on enteral nutrition-induced ventilator-associated pneumonia and the gastrointestinal system in mechanically ventilated patients.

MATERIALS AND METHODS

The present research is a prospective, randomized, controlled clinical trial. This study was completed with 63 patients (31 in the experimental group and 32 in the control group). Data collection was performed using a patient information form, a patient follow-up form, and the Bristol Stool Scale. After patients were under mechanical ventilation for 48 hours, the data collection tools were filled out twice a day for 3 days by visiting the mechanical ventilation patients. The experimental group received 15 minutes of abdominal massage twice a day before nursing care was delivered in the morning and the evening.

RESULTS

According to the intergroup evaluations, the experimental group had lower gastric residual volume and abdominal distension, types of stool closer to normal, and higher defecation frequency. Differences between the groups were statistically significant (P < .05). In accordance with the intragroup evaluations, the experimental group had lower gastric residual volume, abdominal distension, and ventilator-associated pneumonia. The difference between the groups was revealed to be statistically significant (P < .05).

CONCLUSION

Abdominal massage reduces ventilator-associated pneumonia development to a statistically significant degree. Furthermore, it decreases gastric residual volume and abdominal distension, causes stools to be closer to the normal/ideal stool, increases defecation frequency, and regulates bowel movements and excretion (P < .05).

Evaluation of the effect of different sedative doses of dexmedetomidine on the intestinal motility in clinically healthy donkeys (Equus asinus)

AIM

Gastrointestinal effects of different doses of dexmedetomidine in donkeys are still unidentified. The current study aimed to evaluate the impact of different doses of dexmedetomidine on the motility of selected parts of the gastrointestinal tracts in donkeys using transabdominal ultrasonography.

MATERIALS AND METHODS

An experimental crossover study was conducted on 30 healthy donkeys of both sexes (15 males and 15 females; 160 ± 60 kg). With a two-week washout period, each donkey received an injection of either a normal saline solution or three different doses of dexmedetomidine (3, 5, and 7 μg/kg, respectively). All medications were administered intravenously in equal volumes. The contractility of selected intestinal segments (duodenum, jejunum, left colon, right colon, and cecum) was measured 3 min before administration (zero time) and at 15, 30, 45, 60, 90, and 120 minutes after administration.

RESULTS

Small and large intestinal motility was within the normal ranges before IV injection of normal isotonic saline or dexmedetomidine at a dose of 3, 5, and 7 μg/kg. Two Way Repeated Measures ANOVA output of the data displayed a statistically significant the between time and treatments for the contractility of each of the duodenum (P = 0.0029), jejunum (P = 0.0033), left colon (P = 0.0073), right colon (P = 0.0035), and cecum (P = 0.0026), implying that the impact of treatment on the gastric motility varied among different time points. The simple main effect analysis revealed that the IV dexmedetomidine at 3, 5, and 7 μg/kg doses significantly inhibited (P ≤ 0.01) the bowel contractility compared to the administration of isotonic saline.

CONCLUSION

Dose-dependent inhibitory effect of dexmedetomidine on intestinal motility was reported in donkeys following intravenous administration. This inhibitory effect on intestinal motility should be considered in clinical practice.

Efficacy of probiotics or synbiotics for critically ill adult patients: a systematic review and meta-analysis of randomized controlled trials

Background

Microbial dysbiosis in critically ill patients is a leading cause of mortality and septic complications. Probiotics and synbiotics have emerged as novel therapy on gut microbiota to prevent septic complications. However, current evidence on their effects is conflicting. This work aims to systematically review the impact of probiotics or synbiotics in critically ill adult patients.

Methods

A comprehensive search of the PubMed, CBM, Embase, CENTRAL, ISI, and CNKI databases was performed to identify randomized controlled trials that evaluate probiotics or synbiotics in critically ill patients. The quality assessment was based on the modified Jadad's score scale and the Cochrane Handbook for Systematic Reviews of Interventions Version 5.0.1. The major outcome measure was mortality. Secondary outcomes included incidence of septic complications, sepsis incidence, length of intensive care unit (ICU) stay, incidence of non-septic complication, and ventilator day. Data synthesis was conduct by Review Manager 5.4.

Results

A total of 25 randomized controlled trials reporting on 5049 critically ill patients were included. In the intervention group, 2520 participants received probiotics or synbiotics, whereas 2529 participants received standard care or placebo. Pooling data from randomized controlled trials demonstrated a significant reduction in the incidence of ventilator-associated pneumonia (VAP) in the treatment group [(risk ratio (RR) 0.86; 95% confidence interval (CI): 0.78–0.95; p < 0.003, I² = 85%)]. However, in the subgroup analysis, the reduction of incidence of VAP was only significant in patients receiving synbiotics (RR = 0.61, 95% CI: 0.47–0.80, p = 0.0004, I² = 40%) and not significant in those receiving only probiotics (RR = 0.91, 95% CI: 0.82–1.01, p = 0.07, I² = 65%). Moreover, sepsis incidence of critically ill patients was only significantly reduced by the addition of synbiotics (RR = 0.41; 95% CI: 0.22–0.72, p = 0.005, I² = 0%). The incidence of ICU-acquired infections was significantly reduced by the synbiotics therapy (RR = 0.72; 95% CI: 0.58–0.89, p = 0.0007, I² = 79%). There was no significant difference in mortality, diarrhea, or length of ICU stay between the treatment and control groups.

Conclusions

Synbiotics is an effective and safe nutrition therapy in reducing septic complications in critically ill patients. However, in such patients, administration of probiotics alone compared with placebo resulted in no difference in the septic complications.

The effect of opioids on gastrointestinal function in the ICU

Gastrointestinal (GI) dysfunction is common in the critical care setting and is highly associated with clinical outcomes. Opioids increase the risk for GI dysfunction and are frequently prescribed to reduce pain in critically ill patients. However, the role of opioids in GI function remains uncertain in the ICU. This review aims to describe the effect of opioids on GI motility, their potential risk of increasing infection and the treatment of GI dysmotility with opioid antagonists in the ICU setting.

Gut Microbiota and Probiotics/Synbiotics for Modulation of Immunity in Critically Ill Patients

Patients suffering from critical illness have host inflammatory responses against injuries, such as infection and trauma, that can lead to tissue damage, organ failure, and death. Modulation of host immune response as well as infection and damage control are detrimental factors in the management of systemic inflammation. The gut is the motor of multiple organ failure following injury, and it is recognized that gut dysfunction is one of the causative factors of disease progression. The gut microbiota has a role in maintaining host immunity, and disruption of the gut microbiota might induce an immunosuppressive condition in critically ill patients. Treatment with probiotics and synbiotics has been reported to attenuate systemic inflammation by maintaining gut microbiota and to reduce postoperative infectious complications and ventilator-associated pneumonia. The administration of prophylactic probiotics/synbiotics could be an important treatment option for preventing infectious complications and modulating immunity. Further basic and clinical research is needed to promote intestinal therapies for critically ill patients.

Inhibitory Effects of Dexmedetomidine and Propofol on Gastrointestinal Tract Motility Involving Impaired Enteric Glia Ca2+ Response in Mice

Propofol and dexmedetomidine are popular used for sedation in ICU, however, inadequate attention has been paid to their effect on gastrointestinal tract (GIT) motility. Present study aimed to compare the effect of propofol and dexmedetomidine on GIT motility at parallel level of sedation and explore the possible mechanism. Male C57BL/6 mice (8-10 weeks) were randomly divided into control, propofol and dexmedetomidine group. After intraperitoneal injection of propofol or dexmedetomidine, comparable sedative level was confirmed by sedative score, physiological parameters and electroencephalogram (EEG). Different segments of GIT motility in vivo (gastric emptying, small intestine transit, distal colon bead expulsion, stool weight and number of fecal pellets, gastrointestinal transit and whole gut transit time) and colonic migrating motor complexes (CMMCs) pattern in vitro were evaluated. The Ca2+ response of primary enteric glia was examined under the treatment of propofol or dexmedetomidine. There is little difference in physiological parameters and composite permutation entropy index (CPEI) between administration of 50 mg/kg propofol and 40 μg/kg dexmedetomidine, indicated that parallel level of sedation was reached. Data showed that propofol and dexmedetomidine had significantly inhibitory effect on GIT motility while dexmedetomidine was stronger. Also, the amplitude (ΔF/F0) of Ca2+ response in primary enteric glia was attenuated after treated with the sedatives while the effect of dexmedetomidine was greater than propofol. These findings demonstrated that dexmedetomidine caused stronger inhibitory effects on GIT motility in sedative mice, which may involve impaired Ca2+ response in enteric glia. Hence, dexmedetomidine should be carefully applied especially for potential GIT dysmotility patient.

Characterization of esophageal motor activity, gastroesophageal reflux, and evaluation of prokinetic effectiveness in mechanically ventilated critically ill patients: a high-resolution impedance manometry study

BACKGROUND

Motility disorders of upper gastrointestinal tract are common in critical illness and associated with significant clinical consequences. However, detailed quantitative and qualitative analyses of esophageal motor functions are lacking. Therefore, we aimed to characterize the key features of esophageal motility functions using high-resolution impedance manometry (HRIM) and to evaluate an objective link between esophageal motor patterns, gastric emptying, and gastroesophageal reflux. We also studied the prokinetic effects of metoclopramide.

METHODS

We prospectively performed HRIM for 16 critically ill hemodynamically stable patients. Patients were included if they had low gastric volume (LGV; < 100 mL/24 h, n = 8) or high gastric volume (HGV; > 500 mL/24 h, n = 8). The HRIM data were collected for 5 h with intravenous metoclopramide administration (10 mg) after the first 2 h.

RESULTS

The findings were grossly abnormal for all critically ill patients. The esophageal contraction vigor was markedly increased, indicating prevailing hypercontractile esophagus. Ineffective propulsive force was observed for 73% of esophageal activities. Panesophageal pressurization was the most common pressurization pattern (64%). Gastroesophageal reflux predominantly occurred with transient lower esophageal sphincter relaxation. The common features of the LGV group were a hyperreactive pattern, esophagogastric outflow obstruction, and frequent reflux. Ineffective motility with reduced lower esophageal sphincter tone, and paradoxically fewer reflux episodes, was common in the HGV group. Metoclopramide administration reduced the number of esophageal activities but did not affect the number of reflux episodes in either group.

CONCLUSION

All critically ill patients had major esophageal motility abnormalities, and motility patterns varied according to gastric emptying status. Well-preserved gastric emptying and maintained esophagogastric barrier functions did not eliminate reflux. Metoclopramide failed to reduce the number of reflux episodes regardless of gastric emptying status. Trial registration ISRCTN, ISRCTN14399966. Registered 3.9.2020, retrospectively registered. https://www.isrctn.com/ISRCTN14399966 .

Ileus in the critically ill: causes, treatment and prevention

Bowel dysfunction, especially ileus, has been increasingly recognized in critically ill patients. Ileus is commonly associated to constipation, however abnormal motility can also concern the upper digestive tract, therefore impaired gastrointestinal transit (IGT) seems to be a more appropriate term. IGT, especially constipation, is common among patients under mechanical ventilation, occurring in up to 80% of the patients during the first week, and has been associated with worse outcome in intensive care unit (ICU). It is acknowledged that the most relevant definition for constipation in ICU is the absence of stool for the first six days after admission. Concerning the upper digestive intolerance (UDI), the diagnosis should rely only on vomiting and the systematic gastric residual volume (GRV) monitoring should be avoided. IGT results from a complex pathophysiology in which both the critical illness and its specific treatments may have a deleterious role. Both observational and experimental studies have shown the deleterious effect of sepsis, multiorgan failure, sedation (especially opioids) and mechanical ventilation on gut function. To date few studies have reported effect of treatment on IGT and the level of evidence is low. However, cholinesterase inhibitors seem safe and could probably be used in case of constipation but remains poorly prescribed. Prevention with bowel management protocol using osmotic laxatives appears to be safe but did not demonstrate its effectiveness. For patients treated with high posology of opioids during sedation, enteral opioid antagonists may be a promising strategy.

Impact of intestinal microbiota in patients with heart failure: A systematic review

Heart failure (HF) is a chronic disease with significant morbidity and mortality. Substantial haemodynamic changes such as hypoperfusion and intestinal congestion can alter the composition of the intestinal microbiota in patients with HF. The aim of this systematic review is to evaluate the influence of bowel function in patients with HF and the possible role of the intestinal microbiota in the development and evolution of the latter. Eleven studies were included in the review. These studies seem to confirm that HF patients present with substantial abnormalities in the composition of their intestinal microbiota. Trimethylamine N-oxide is identified as a key mediator between the alterations in the intestinal microbiota and HF and correlates with worse prognosis in HF patients. In conclusion, patients with HF present with frequent abnormalities in the characteristics of their intestinal microbiota, which may play a role in the prognosis of the disease.

Perioperative Fluid Accumulation Impairs Intestinal Contractility to a Similar Extent as Peritonitis and Endotoxemia

BACKGROUND

Perioperative resuscitation with large amounts of fluid may cause tissue edema, especially in the gut, and thereby impairing its functions. This is especially relevant in sepsis where capillaries become leaky and fluid rapidly escapes to the pericapillary tissue. We assessed the effects of endotoxemia and peritonitis, and the use of high and moderate volume fluid resuscitation on jejunal contractility. We hypothesized that both endotoxemia and peritonitis impair jejunum contractility and relaxation, and that this effect is aggravated in peritonitis and with high fluid administration.

METHODS

Pigs were randomized to endotoxin (n = 16), peritonitis (n = 16), or sham operation (n = 16), and either high (20 mL/kg/h) or moderate volume (10 mL/kg/h) fluid resuscitation for 24 h or until death. At the end of the experiment, jejunal contractility and relaxation were measured in vitro using acetylcholine and sodium nitroprusside reactivity, and the effect of nitric oxide synthase inhibition (NOS-I) was assessed.

RESULTS

Mortality in the respective groups was 88% (peritonitis high), 75% (endotoxemia high), 50% (peritonitis moderate), 13% (endotoxemia moderate and sham operation high), and 0% (sham operation moderate volume resuscitation). Although gut perfusion was preserved in all groups, jejunal contractility was impaired in the two peritonitis and two endotoxemia groups, and similarly also in the sham operation group treated with high but not with moderate volume fluid resuscitation (model-fluid-contraction-interaction, P = 0.036; maximal contractility 136 ± 28% [average of both peritonitis, both endotoxemia and sham operation high-volume groups) vs. 170 ± 74% of baseline [sham operation moderate-volume group]). NOS-I reduced contractility (contraction-inhibition-interaction, P = 0.011) without significant differences between groups and relaxation was affected neither by peritonitis and endotoxemia nor by the fluid regimen.

CONCLUSIONS

Intestinal contractility is similarly impaired during peritonitis and during endotoxemia. Moreover, perioperative high-volume fluid resuscitation in sham-operated animals also decreases intestinal contractility. This may have consequences for postoperative recovery.

Interstitial cells of Cajal are diminished in critically ill patients: Autopsy cases

OBJECTIVE

Gastrointestinal dysmotility in critically ill patients is important as enteral nutrition is crucial. However, normal gut motility is impaired under conditions of critical illness subsequent to severe insult. Interstitial cells of Cajal (ICC) form an extensive network associated with the myenteric plexus in the enteric nervous system. There are few reports about ICC distribution in critically ill patients. The aim of this study was to evaluate ICC in critically ill patients.

METHODS

Postmortem colon harvest was obtained from critically ill patients. Control specimens were obtained from patients without bowel movement problems who underwent hemicolectomy. The tissues were stained with c-Kit for ICC. The number of ICC was identified by counting from 10 high-power fields (HPFs).

RESULTS

Specimens from six patients were analyzed and compared with those from six control patients. All patients had abnormalities of crypt architecture and inflammatory cell infiltrations. Mucosal thickness tended to be lower in the critically ill patients than in the controls (147 ± 47 versus 231 ± 127 μm; P = 0.15). Muscle layer thickness tended to be higher in the critically ill patients than in the controls (494 ± 163 versus 394 ± 258 μm; P = 0.44). ICC in the critically ill patients were almost depleted in the colon compared with those in the controls. Significantly fewer ICC were present in the critically ill patients than in the controls (0.45 versus 7.25 cells/HPF; P < 0.05).

CONCLUSIONS

Critical illness is associated with diminished numbers of ICC in the colon. This finding could have implications for dysmotility in critically ill patients.

Gallbladder Dyskinesia Is Associated With an Impaired Postprandial Fibroblast Growth Factor 19 Response in Critically Ill Patients

Critical illness is associated with a disturbed regulation of gastrointestinal hormones resulting in functional and metabolic anomalies. Fibroblast growth factor 19 (FGF19) is an ileum-derived metabolic hormone induced by bile salts upon gallbladder emptying after enteral nutrient stimulation. Our aim was to study the nutrient-stimulated FGF19 response in 24 patients admitted to the intensive care unit (ICU) compared with 12 healthy controls. All subjects received intraduodenal high-lipid nutrient infusion for 120 minutes. Blood was collected every 30 minutes until 1 hour after infusion, and gallbladder emptying was studied by ultrasound. Serum levels of bile salts and FGF19 were assessed. ICU patients had significantly higher fasting bile salt serum levels compared with controls, whereas FGF19 serum levels were similar. In both groups, nutrient infusion elicited substantial bile salt elevations (P < 0.001), peaking at 90 minutes, albeit with a significantly lower peak in the ICU patients (P = 0.029). In controls, FGF19 was significantly elevated relative to baseline from 120 minutes onward (P < 0.001). In ICU patients, the FGF19 response was blunted, as reflected by significantly lower FGF19 elevations at 120, 150, and 180 minutes (P < 0.05) and significantly lower area under the curve (AUC) values compared with controls (P < 0.001). Gallbladder dysmotility was associated with the impaired FGF19 response in critical illness. The gallbladder ejection fraction correlated positively with FGF19 AUC values (ρ = +0.34, P = 0.045). In 10 of 24 ICU patients, gallbladder emptying was disturbed. These patients had significantly lower FGF19 AUC values (P < 0.001). Gallbladder emptying and the FGF19 response were respectively disturbed or absent in patients receiving norepinephrine. Conclusion: The nutrient-stimulated FGF19 response is impaired in ICU patients, which is mechanistically linked to gallbladder dysmotility in critical illness. This may contribute to disturbed liver metabolism in these patients and has potential as a nutritional biomarker.

Intestinal failure in adults: Recommendations from the ESPEN expert groups

BACKGROUND & AIMS

Intestinal failure (IF) is defined as "the 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". Functionally, it may be classified as type I acute intestinal failure (AIF), type II prolonged AIF and type III chronic intestinal failure (CIF) The ESPEN Workshop on IF was held in Bologna, Italy, on 15-16 October 2017 and the aims of this document were to highlight the current state of the art and future directions for research in IF.

METHODS

This paper represents the opinion of experts in the field, based on current evidence. It is not a formal review, but encompasses the current evidence, with emphasis on epidemiology, classification, diagnosis and management.

RESULTS

IF is the rarest form of organ failure and can result from a variety of conditions that affect gastrointestinal anatomy and function adversely. Assessment, diagnosis, and short and long-term management involves a multidisciplinary team with diverse expertise in the field that aims to reduce complications, increase life expectancy and improve quality of life in patients.

CONCLUSIONS

Both AIF and CIF are relatively rare conditions and most of the published work presents evidence from small, single-centre studies. Much remains to be investigated to improve the diagnosis and management of IF and future studies should rely on multidisciplinary, multicentre and multinational collaborations that gather data from large cohorts of patients. Emphasis should also be placed on partnership with patients, carers and government agencies in order to improve the quality of research that focuses on patient-centred outcomes that will help to improve both outcomes and quality of life in patients with this devastating condition.

Decrease in exhaled hydrogen as marker of congestive heart failure

Objective

Hydrogen excretion is thought to be related to systemic antioxidation activity. H₂ selectively reduces the hydroxyl radical of free hydrogen (·OH), a highly cytotoxic form of reactive oxygen species, in cultured cells.

Methods

We investigated whether exhaled H₂ decreased during night sleep, reflected ·OH production and was associated with heart failure severity. We enrolled 108 patients with chronic heart failure (CHF) and 15 control participants without CHF. H₂ concentration was measured by gas chromatography in exhaled breath collected before sleep and in the morning after overnight fasting. Overnight change in H₂ concentration (ΔH₂) was calculated. Mitochondrial morphology evaluated by transmission electron microscopy in endomyocardial biopsies collected from 18 patients with dilated cardiomyopathy.

Results

ΔH₂ was significantly lower in patients with CHF compared with controls (−4.3±1.0 vs 2.0±2.1 ppm, p=0.030) and was positively correlated with cardiac index (CI; r = −0.285, p=0.003). Patients with a ΔH₂<0 ppm had a significantly lower CI compared with those who had a ΔH₂>0 ppm (2.85±0.61 vs 3.24±0.65 L/min/m², p=0.005). ΔH₂ was negatively correlated with both the percentage of vacuole-containing mitochondria and indices of cristae remodelling (r = −0.61, p=0.007).

Conclusions

Decrease in exhaled H₂ during night sleep was associated with CHF severity. ΔH₂ warrants investigation as marker of CHF severity.

Diabetes-Specific Formulae Versus Standard Formulae as Enteral Nutrition to Treat Hyperglycemia in Critically Ill Patients: Protocol for a Randomized Controlled Feasibility Trial

Background

During critical illness, hyperglycemia is prevalent and is associated with adverse outcomes. While treating hyperglycemia with insulin reduces morbidity and mortality, it increases glycemic variability and hypoglycemia risk, both of which have been associated with an increase in mortality. Therefore, other interventions which improve glycemic control, without these complications should be explored. Nutrition forms part of standard care, but the carbohydrate load of these formulations has the potential to exacerbate hyperglycemia. Specific diabetic-formulae with a lesser proportion of carbohydrate are available, and these formulae are postulated to limit glycemic excursions and reduce patients’ requirements for exogenous insulin.

Objective

The primary outcome of this prospective, blinded, single center, randomized controlled trial is to determine whether a diabetes-specific formula reduces exogenous insulin administration. Key secondary outcomes include the feasibility of study processes as well as glycemic variability.

Methods

Critically ill patients will be eligible if insulin is administered whilst receiving exclusively liquid enteral nutrition. Participants will be randomized to receive a control formula, or a diabetes-specific, low glycemic index, low in carbohydrate study formula. Additionally, a third group of patients will receive a second diabetes-specific, low glycemic index study formula, as part of a sub-study to evaluate its effect on biomarkers. This intervention group (n=12) will form part of recruitment to a nested cohort study with blood and urine samples collected at randomization and 48 hours later for the first 12 participants in each group with a secondary objective of exploring the metabolic implications of a change in nutrition formula. Data on relevant medication and infusions, nutrition provision and glucose control will be collected to a maximum of 48 hours post randomization. Baseline patient characteristics and anthropometric measures will be recorded. A 28-day phone follow-up will explore weight and appetite changes as well as blood glucose control pre and post intensive care unit (ICU) discharge.

Results

Recruitment commenced in February 2015 with an estimated completion date for data collection by May 2018. Results are expected to be available late 2018.

Conclusions

This feasibility study of the effect of diabetes-specific formulae on the administration of insulin in critically ill patients and will inform the design of a larger, multi-center trial.

Trial Registration

Australian New Zealand Clinical Trial Registry (ANZCTR):12614000166673; https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?ACTRN=12614000166673 (Archived by WebCite at http://www.webcitation.org/6xs0phrVu)

Gastrointestinal motility dysfunction in critically ill patients: Pathogenesis, clinical assessment, and treatment

Gastrointestinal motility dysfunction is a common clinical complication in ICU patients, which can lead to difficulty in enteral nutrition, vomiting, diarrhea, increased intra-abdominal pressure, ventilator associated pneumonia, intestinal flora displacement, and other adverse reactions. The clinical features of gastrointestinal dysfunction mainly include gastric emptying disturbance, intestinal dysfunction, and gastrointestinal motility disorders. The causes of gastrointestinal motility dysfunction in ICU patients are complex and the clinical evaluation of gastrointestinal dysfunction is difficult. These factors have led to the fact that gastrointestinal motility monitoring techniques have not been widely used in clinical practice. Timely detection and correction of gastrointestinal motility dysfunction in ICU patients can improve outcomes. This article reviews the etiology, clinical evaluation, and treatment of gastrointestinal motility dysfunction in ICU patients.

Anti-inflammatory Effects of Fungal Metabolites in Mouse Intestine as Revealed by In vitro Models

Inflammatory bowel diseases (IBD), which include Crohn's disease and ulcerative colitis, are chronic inflammatory disorders that can affect the whole gastrointestinal tract or the colonic mucosal layer. Current therapies aiming to suppress the exaggerated immune response in IBD largely rely on compounds with non-satisfying effects or side-effects. Therefore, new therapeutical options are needed. In the present study, we investigated the anti-inflammatory effects of the fungal metabolites, galiellalactone, and dehydrocurvularin in both an in vitro intestinal inflammation model, as well as in isolated myenteric plexus and enterocyte cells. Administration of a pro-inflammatory cytokine mix through the mesenteric artery of intestinal segments caused an up-regulation of inflammatory marker genes. Treatment of the murine intestinal segments with galiellalactone or dehydrocurvularin by application through the mesenteric artery significantly prevented the expression of pro-inflammatory marker genes on the mRNA and the protein level. Comparable to the results in the perfused intestine model, treatment of primary enteric nervous system (ENS) cells from the murine intestine with the fungal compounds reduced expression of cytokines such as IL-6, TNF-α, IL-1β, and inflammatory enzymes such as COX-2 and iNOS on mRNA and protein levels. Similar anti-inflammatory effects of the fungal metabolites were observed in the human colorectal adenocarcinoma cell line DLD-1 after stimulation with IFN-γ (10 ng/ml), TNF-α (10 ng/ml), and IL-1β (5 ng/ml). Our results show that the mesenterially perfused intestine model provides a reliable tool for the screening of new therapeutics with limited amounts of test compounds. Furthermore, we could characterize the anti-inflammatory effects of two novel active compounds, galiellalactone, and dehydrocurvularin which are interesting candidates for studies with chronic animal models of IBD.

Comparison of Two Different Enteral Nutrition Protocol in Critically Ill Patients

OBJECTIVE

In this study, two enteral nutrition protocols with different gastric residual volumes (GRVs) and different monitoring intervals were compared with respect to gastrointestinal intolerance findings in intensive care unit (ICU) patients.

METHODS

The study was carried out prospectively in 60 patients in the anaesthesiology and reanimation ICU under mechanical ventilation support, who were scheduled to take enteral feeding. Patients were sequentially divided into two groups: Group 1, GRV threshold of 100 mL, and monitoring interval of 4 hours, and Group 2, GRV threshold of 200 mL, monitoring interval of 8 hours. To test the significant difference between the groups, Student's t test, chi-square text and Fisher exact test were used.

RESULTS

In Group 1, 3.3% vomiting, 6.6% diarrhoea was observed; in Group 2, 16.6% vomiting, 10% diarrhoea. In terms of total intolerance (vomiting and/or diarrhoea) of the two groups, the incidence was significantly higher in Group 2 (33.3%) than in Group 1 (10%) (p=0.02).

CONCLUSION

According to the results of the study, a lower gastrointestinal intolerance rate was detected in the GRV threshold 100 mL, monitoring interval for 4 hours protocol (Group 1) than in GRV threshold 200 mL, monitoring interval for 8 hours protocol (Group 2); Group 1 may be preferred renovation.

Energy-Dense Formulae May Slow Gastric Emptying in the Critically Ill

BACKGROUND

Enteral feed intolerance occurs frequently in critically ill patients and can be associated with adverse outcomes. "Energy-dense formulae" (ie, >1 kcal/mL) are often prescribed to critically ill patients to reduce administered volume and are presumed to maintain or increase calorie delivery. The aim of this study was to compare gastric emptying of standard and energy-dense formulae in critically ill patients.

METHODS

In a retrospective comparison of 2 studies, data were analyzed from 2 groups of patients that received a radiolabeled 100-mL "meal" containing either standard calories (1 kcal/mL) or concentrated calories (energy-dense formulae; 2 kcal/mL). Gastric emptying was measured using a scintigraphic technique. Radioisotope data were collected for 4 hours and gastric emptying quantified. Data are presented as mean ± SE or median [interquartile range] as appropriate.

RESULTS

Forty patients were studied (n = 18, energy-dense formulae; n = 22, standard). Groups were well matched in terms of demographics. However, patients in the energy-dense formula group were studied earlier in their intensive care unit admission (P = .02) and had a greater proportion requiring inotropes (P = .002). A similar amount of calories emptied out of the stomach per unit time (P = .57), but in patients receiving energy-dense formulae, a greater volume of meal was retained in the stomach (P = .045), consistent with slower gastric emptying.

CONCLUSIONS

In critically ill patients, the administration of the same volume of a concentrated enteral nutrition formula may not result in the delivery of more calories to the small intestine over time because gastric emptying is slowed.

Gastrointestinal dysmotility disorders in critically ill dogs and cats

OBJECTIVE

To review the human and veterinary literature regarding gastrointestinal (GI) dysmotility disorders in respect to pathogenesis, patient risk factors, and treatment options in critically ill dogs and cats.

ETIOLOGY

GI dysmotility is a common sequela of critical illness in people and small animals. The most common GI motility disorders in critically ill people and small animals include esophageal dysmotility, delayed gastric emptying, functional intestinal obstruction (ie, ileus), and colonic motility abnormalities. Medical conditions associated with the highest risk of GI dysmotility include mechanical ventilation, sepsis, shock, trauma, systemic inflammatory response syndrome, and multiple organ failure. The incidence and pathophysiology of GI dysmotility in critically ill small animals is incompletely understood.

DIAGNOSIS

A presumptive diagnosis of GI dysmotility is often made in high-risk patient populations following detection of persistent regurgitation, vomiting, lack of tolerance of enteral nutrition, abdominal pain, and constipation. Definitive diagnosis is established via radioscintigraphy; however, this diagnostic tool is not readily available and is difficult to perform on small animals. Other diagnostic modalities that have been evaluated include abdominal ultrasonography, radiographic contrast, and tracer studies.

THERAPY

Therapy is centered at optimizing GI perfusion, enhancement of GI motility, and early enteral nutrition. Pharmacological interventions are instituted to promote gastric emptying and effective intestinal motility and prevention of complications. Promotility agents, including ranitidine/nizatidine, metoclopramide, erythromycin, and cisapride are the mainstays of therapy in small animals.

PROGNOSIS

The development of complications related to GI dysmotility (eg, gastroesophageal reflux and aspiration) have been associated with increased mortality risk. Institution of prophylaxic therapy is recommended in high-risk patients, however, no consensus exists regarding optimal timing of initiating prophylaxic measures, preference of treatment, or duration of therapy. The prognosis for affected small animal patients remains unknown.

Pathogenic Gut Flora in Patients With Chronic Heart Failure

OBJECTIVES

The goal of this study was to measure the presence of pathogenic gut flora and intestinal permeability (IP) and their correlations with disease severity, venous blood congestion, and inflammation in patients with chronic heart failure (CHF).

BACKGROUND

Evidence suggests that translocation of gut flora and/or their toxins from the intestine to the bloodstream is a possible trigger of systemic CHF inflammation. However, the relation between pathogenic gut flora and CHF severity, as well as IP, venous blood congestion as right atrial pressure (RAP), and/or systemic inflammation (C-reactive protein [CRP]), is still unknown.

METHODS

This study analyzed 60 well-nourished patients in stable condition with mild CHF (New York Heart Association [NYHA] functional class I to II; n = 30) and moderate to severe CHF (NYHA functional class III to IV; n = 30) and matched healthy control subjects (n = 20). In all subjects, the presence and development in the feces of bacteria and fungi (Candida species) were measured; IP according to cellobiose sugar test results was documented. The study data were then correlated with RAP (echocardiography) and systemic inflammation.

RESULTS

Compared with normal control subjects, the entire CHF population had massive quantities of pathogenic bacteria and Candida such as Campylobacter (85.3 ± 3.7 CFU/ml vs. 1.0 ± 0.3 CFU/ml; p < 0.001), Shigella (38.9 ± 12.3 CFU/ml vs. 1.6 ± 0.2 CFU/ml; p < 0.001), Salmonella (31.3 ± 9.1 CFU/ml vs 0 CFU/ml; p < 0.001), Yersinia enterocolitica (22.9 ± 6.3 CFU/ml vs. 0 CFU/ml; p < 0.0001), and Candida species (21.3 ± 1.6 CFU/ml vs. 0.8 ± 0.4 CFU/ml; p < 0.001); altered IP (10.2 ± 1.2 mg vs. 1.5 ± 0.8 mg; p < 0.001); and increased RAP (12.6 ± 0.6 mm Hg) and inflammation (12.5 ± 0.6 mg/dl). These variables were more pronounced in patients with moderate to severe NYHA functional classes than in patients with the mild NYHA functional class. Notably, IP, RAP, and CRP were mutually interrelated (IP vs. RAP, r = 0.55; p < 0.0001; IP vs. CRP, r = 0.78; p < 0.0001; and RAP vs. CRP, r = 0.78; p < 0.0001).

CONCLUSIONS

This study showed that patients with CHF may have intestinal overgrowth of pathogenic bacteria and Candida species and increased IP associated with clinical disease severity, venous blood congestion, and inflammation.

Gastric Dysmotility in Critically Ill Children: Pathophysiology, Diagnosis, and Management

OBJECTIVE

We aimed to review gastric dysmotility in critically ill children: 1) its pathophysiology, with a focus on critical care diseases and therapies that affect gastric motility, 2) diagnostic methodologies, and 3) current and future potential therapies.

DATA SOURCES

Eligible studies were identified from PubMed and MEDLINE.

STUDY SELECTION

Literature search included the following key terms: "gastric emptying," "gastric motility/dysmotility," "gastrointestinal motility/dysmotility," "nutrition intolerance," and "gastric residual volume."

DATA EXTRACTION

Studies since 1995 were extracted and reviewed for inclusion by the authors related to the physiology, pathophysiology, diagnostic methodologies, and available therapies for gastric emptying.

DATA SYNTHESIS

Delayed gastric emptying, a common presentation of gastric dysmotility, is present in up to 50% of critically ill children. It is associated with the potential for aspiration, ventilator-associated pneumonia, and inadequate delivery of enteral nutrition and may affect the efficacy of enteral medications, all of which may be result in poor patient outcomes. Gastric motility is affected by critical illness and its associated therapies. Currently available diagnostic tools to identify gastric emptying at the bedside have not been systematically studied and applied in this cohort. Gastric residual volume measurement, used as an indirect marker of delayed gastric emptying in PICUs around the world, may be inaccurate.

CONCLUSIONS

Gastric dysmotility is common in critically ill children and impacts patient safety and outcomes. However, it is poorly understood, inadequately defined, and current therapies are limited and based on scant evidence. Understanding gastric motility and developing accurate bedside measures and novel therapies for gastric emptying are highly desirable and need to be further investigated.

The reasons for insufficient enteral feeding in an intensive care unit: A prospective observational study

BACKGROUND

Although enteral nutrition (EN) in critically ill patients is increasingly common, enteral underfeeding remains problematic. In the present study, we aimed to identify the reasons for insufficient EN.

METHODS

In this single-centre, prospective, observational study in a general intensive care unit, the nurses documented cases experiencing enteral underfeeding during three-month study period. Decisions regarding EN were made and substantiated by the doctors. No feeding protocol was in use. The EN rate was assessed daily and considered insufficient if less than 50 kcal/h was administered and the rate had not increase in the previous 12 hour period.

RESULTS

Eighty-seven patients were screened for 707 patient-days. Nurses documented 141 instances of insufficient EN in 49 patients (56.7% of all study subjects). EN was not initiated in 61% of these cases, EN was stopped in 14%, EN decreased in 2% and insufficient EN was not increased in 23%. EN was not initiated primarily due to surgical reasons. EN was not increased due to clinical instability. EN was decreased or stopped primarily due to high gastric residual volumes (GRV). The study served as step one in a quality improvement process and resulted in the introduction of a nurse-driven feeding protocol.

CONCLUSION

The main reasons for insufficient EN in intensive care patients include recent GI surgery, shock and large GRV. EN is commonly withheld for several days after GI surgery, whereas in shock there was a prohibition on increasing EN towards the target. Insufficient EN is highly prevalent; the incidence of EN should be reduced by training and the acceptance of more liberal EN policies.

Gut microbiota and environment in patients with major burns – a preliminary report

INTRODUCTION

The gut is an important target organ after severe insult. Gut microbiota have an important role in immune response. However, the gut microbiota and environment have not been clarified in patients with burns. Therefore, we serially evaluated the gut microbiota and environment in patients with major burns.

METHODS

Fecal samples from five patients with major burns were measured for quantitative evaluation of the gut microbiota.

RESULTS

In the four survivors of major burns, the numbers of beneficial bacteria, especially those of total obligate anaerobes and Bifidobacterium, initially decreased, but then increased as the condition of the survivors improved. By contrast, the numbers severely decreased in the non-survivor as gut failure and sepsis progressed. The number of pathogenic bacteria such as Pseudomonas and Candida did not continue to increase in the survivors, whereas in the non-survivor the number increased and continued to higher counts. Short-chain fatty acids such as propionic and butyric acids decreased to lower-than-normal levels but tended to increase after recovery in the survivors. The levels remained below normal in the non-survivor.

CONCLUSIONS

The gut microbiota and environment are severely altered in patients with major burns. Consequently, abnormal gut conditions may have an influence on the systemic inflammatory response and multiple organ dysfunction syndrome. A novel treatment to maintain the gut microbiota and environment is expected in the future.

Rapid and Sustained Long-Term Decrease of Fecal Short-Chain Fatty Acids in Critically Ill Patients With Systemic Inflammatory Response Syndrome

BACKGROUND

The gut is an important target organ for injury after severe insult. Short-chain fatty acids (SCFAs) are end-products of fermentation of dietary fibers by anaerobic microbiota. They are related to intestinal energy, motility, and transport and to protective effects against infection and inflammation. However, there are few clinical data on SCFAs in critically ill patients. We evaluated serial change in fecal SCFAs in patients with severe systemic inflammatory response syndrome (SIRS).

PATIENTS AND METHODS

This study included 140 intensive care unit (ICU) patients who fulfilled the criteria of SIRS and had a serum C-reactive protein level of >10 mg/dL. A fecal sample was used for quantitative measurement of fecal SCFA (butyrate, propionate, and acetate) concentrations by high-performance liquid chromatography. Fecal SCFAs were evaluated weekly for 6 weeks after admission. Data obtained from patients were compared with corresponding data from healthy volunteers.

RESULTS

SIRS resulted from infection in 78 patients, trauma in 30, burns in 12, and other causes in 20. Fecal concentrations of butyrate, propionate, and acetate in these patients decreased significantly compared with those in healthy volunteers and remained low throughout the 6 weeks of the patients' ICU stay. Fecal concentrations of SCFAs in the patients with gastrointestinal complications, including enteritis and dysmotility, were lower than those in the patients without gastrointestinal complications.

CONCLUSIONS

Concentrations of fecal SCFAs in patients with severe SIRS were significantly lower than those in healthy volunteers over a 6-week period. Maintenance of SCFAs may have therapeutic potential to prevent gastrointestinal complications in critically ill patients.

Probiotic/synbiotic therapy for treating critically ill patients from a gut microbiota perspective

The gut is an important target organ for stress caused by severe insults such as sepsis, trauma, burn, shock, bleeding and infection. Severe insult to the gut is considered to have an important role in promoting infectious complications and multiple organ dysfunction syndrome. These are sequelae of interactions between deteriorated intestinal epithelium, the immune system and commensal bacteria. The gut is the "motor" of multiple organ failure, and now it is recognized that gut dysfunction is a causative factor in disease progression. The gut flora and environment are significantly altered in critically ill patients, and the number of obligate anaerobes is associated with prognosis. Synbiotic therapy is a combination of probiotics and prebiotics. Probiotic, prebiotic and synbiotic treatment has been shown to be a promising therapy to maintain and repair the gut microbiota and gut environment. In the critically ill, such as major abdominal surgery, trauma and ICU patients, synbiotic therapy has been shown to significantly reduce septic complications. Further basic and clinical research would clarify the underlying mechanisms of the therapeutic effect of probiotic/synbiotic treatment and define the appropriate conditions for use.

Nourishing the dysfunctional gut and whey protein

PURPOSE OF REVIEW

This review discusses the mechanisms of the dysfunctional gut during the critical illness and the possibility that an immunonutrient such as whey protein can play a role in better tolerance of enteral nutrition, also decreasing inflammation and increasing anti-inflammatory defenses.

RECENT FINDINGS

Impaired gastric motor function and associated feed intolerance are common issues in critically ill patients. Some studies have been published with enteral nutrition enriched with whey protein as a dietary protein supplement that provides antimicrobial activity, immune modulation, improving muscle strength and body composition, and preventing cardiovascular disease and osteoporosis.

SUMMARY

Early enteral feeding will enhance patient recovery and the use of enteral diets enriched with whey protein may play a role in these patients.

Intra-abdominal hypertension in patients with sellar region tumors

Background

Data on intra-abdominal hypertension [IAH] and secondary abdominal compartment syndrome [ACS] due to neurological insults are limited.

Methods

This was a prospective observational study conducted between January 2010 and January 2011 in the neurological ICU [NICU]. Forty-one consecutive patients with sellar region tumors [SRT] were enrolled into the study. If conservative therapy was ineffective in patients with ACS, thoracic epidural anesthesia [EA] was performed. Primary endpoint was defined as the efficacy of conservative treatment and EA in patients with IAH and ACS; secondary endpoint, the influence of IAH and ACS on outcomes.

Results

Of the 41 patients, 13 (31.7%) had normal intra-abdominal pressure and 28 (68.3%) developed IAH, of whom 9 (22%) had ACS (group II). On average, IAH developed on the second postoperative day, while ACS, between the third and the fifth day. Multiple organ dysfunction developed in 3 (23.1%) patients of group I and in 23 (82%) patients of group II (p = 0.0003). Ileus due to gastrointestinal dysmotility was present in 6 (46.2%) patients of group I and in all patients of group II (p = 0.0001). Significant risk factors for ileus were diencephalon dysfunction (whole group - in 33 patients (80.5%); group I - in 6 patients (46.2%); group II - in 27 patients (96.4%), p = 0.0002) and sepsis (whole group - in 8 patients (19.5%); group I - no cases; group II - in 8 patients (28.6%), p = 0.03). Conservative treatment was effective in the majority of patients (78.9%) with IAH and only in 3 (33%) patients with ACS. Thoracic EA was performed in four patients with ACS with success. Length of stay in the NICU was 6.5 ± 4.6 days in group I and 24.1 ± 25.7 (p = 0.02) days in group II. Five out of nine (55.6%) patients with ACS died. None of these patients received EA. All patients with EA had favorable outcomes.

Conclusion

The development of IAH is common after SRT surgery. If conservative treatment is ineffective, EA can be considered in patients with secondary ACS. Further studies are warranted.

Increased proportion of nitric oxide synthase immunoreactive neurons in rat ileal myenteric ganglia after severe acute pancreatitis

BACKGROUND

Severe acute pancreatitis (SAP) remains a potentially life-threatening disease. Gastrointestinal motility disturbance such as intestinal ileus is seen in every case. By now, the mechanisms of pancreatitis-induced ileus are largely unknown. The main purpose of the present study was to observe changes of nitric oxide synthase-immunoreactive (NOS-IR) neurons in ileal myenteric ganglia in SAP rats with gastrointestinal dysmotility, trying to explore underlying nervous mechanisms of pancreatitis-induced ileus.

METHODS

Twenty Sprague Dawley rats were randomly divided into sham operated group and SAP group. SAP was induced by retrograde cholangiopancreatic duct injection of 5% sodium taurocholate. Abdominal X-ray and intestinal transit were performed to detect the existence of paralytic ileus and intestinal dysmotility. Pathological damage of pancreas was evaluated. Double-immunolabeling was employed for the whole-mount preparations of ileal myenteric ganglia. The morphology of NOS-IR neurons were observed and the percentage of NOS-IR neurons was calculated based on the total Hu-immunoreactive neurons. Total RNA of ileum was extracted according to Trizol reagent protocol. Neuronal NOS (nNOS) mRNA expression was evaluated by RT-PCR.

RESULTS

The small intestinal transit index in the SAP group was significantly lower compared with the sham operated group (29.21±3.68% vs 52.48±6.76%, P<0.01). The percentage of NOS-IR neurons in ileal myenteric ganglia in the SAP group was significantly higher than that in the sham operated group (37.5±12.28% vs 26.32±16.15%, P<0.01). nNOS mRNA expression in ileum of SAP group was significantly higher than that in the sham operated group (1.02±0.10 vs 0.70±0.06, P<0.01).

CONCLUSIONS

The increased quantity of NOS-IR neurons in ileal myenteric ganglia and increased nNOS mRNA expression may suggest nNOS over expression as one of the nervous mechanisms of gastrointestinal dysmotility in SAP rat.

Enteral nutrition in patients with severe traumatic brain injury: reasons for intolerance and medical management

Approximately, 50% of patients with severe traumatic brain injury (TBI) exhibit intolerance to enteral nutrition (EN). This intolerance hampers the survival and rehabilitation of this subpopulation to a great extent, and poses various difficulties for clinicians due to its complex underlying mechanisms. This review discusses the possible reasons for intolerance to EN following severe TBI, current trends in medical management, as well as other related issues that are experienced by many clinicians.

Gastrointestinal dysmotility is associated with altered gut flora and septic mortality in patients with severe systemic inflammatory response syndrome: a preliminary study

BACKGROUND

The gut is an important target organ for injury after severe insult, and resolution of feeding intolerance is crucial for critically ill patients. We investigated gut flora and motility to evaluate the impact of gastrointestinal dysmotility on septic complications in patients with severe systemic inflammatory response syndrome (SIRS).

METHODS

Sixty-three ICU patients with severe SIRS were divided into two groups depending on their intestinal condition. Patients with feeding intolerance comprised patients who had feeding intolerance, defined as ≥ 300 mL reflux from nasal gastric feeding tube in 24 h, and patients without feeding intolerance comprised patients with no feeding intolerance. We compared fecal microflora, incidences of bacteremia, and mortality between these groups.

KEY RESULTS

Analysis of feces showed that patients with feeding intolerance had significantly lower numbers of total obligate anaerobes including Bacteroidaceae and Bifidobacterium, higher numbers of Staphylococcus, lower concentrations of acetic acid and propionic acid, and higher concentrations of succinic acid and lactic acid than those in patients without feeding intolerance (P ≤ 0.05). Patients with feeding intolerance had higher incidences of bacteremia (86%vs 18%) and mortality (64%vs 20%) than did patients without feeding intolerance (P ≤ 0.05).

CONCLUSIONS & INFERENCES

Gut flora and organic acids were significantly altered in patients with severe SIRS complicated by gastrointestinal dysmotility, which was associated with higher septic mortality in SIRS patients.

[Intraabdominal hypertension and abdominal compartment syndrome]

Although intraabdominal pressure (IAP) has been studied for more than 100 years, the concepts of intraabdominal hypertension (IAH) and abdominal compartmental syndrome (ACS) have only been developed as clinical entities of interest in intensive care in the last 5 years. At the first Congress on Abdominal Compartment Syndrome in December 2004, a series of definitions were established, which were published in 2006. IAH is defined as IAP ≥ 12 mmHg and is classified in four severity grades, the maximum grade being ACS, with the development of multiorgan failure. The incidence of IAH in patients in intensive care units is high, around 30% at admission and 64% in those with a length of stay of 7 days. The increase in IAP leads to reduced vascular flow to the splenic organs, increased intrathoracic pressure and decreased venous return, with a substantial reduction in cardiac output. If IAH persists, these physiopathologic episodes are followed by the development of multiorgan failure with renal, cardiocirculatory and respiratory failure and intestinal ischemia. Mortality from untreated ACS is higher than 60%. The only treatment for ACS is surgical decompression. In patients with moderate IAH, medical treatment should be optimized, based on the following measures: a) serial IAP monitoring; b) optimization of systemic perfusion and the function of the distinct systems in patients with high IAP; c) instauration of specific measures to decrease IAP; and d) early surgical decompression for refractory IAH. The application of the medical measures that can reduce IAP and early abdominal decompression in ACS improve survival in critically ill patients with IAH.