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

The Efficacy of Parenteral Nutrition and Enteral Nutrition Supports in Traumatic Brain Injury: A Systemic Review and Network Meta-Analysis

Background

Enteral nutrition (EN) is often used in patients with traumatic brain injury (TBI), but some studies have shown that EN has its disadvantages. However, it is not clear which nutritional support is appropriate to reduce mortality, improve prognosis, and improve nutritional status in patients with TBI. We performed this Bayesian network meta-analysis to evaluate the improvement of nutritional indicators and the clinical outcomes of patients with TBI.

Methods

We systematically searched PubMed, Embase, Cochrane Library, and Web of Science from inception until December 2021. All randomized controlled trials (RCTs) which compared the effects of different nutritional supports on clinical outcomes and nutritional indicators in patients with TBI were included. The co-primary outcomes included mortality and the value of serum albumin. The secondary outcomes were nitrogen balance, the length of study (LOS) in the ICU, and feeding-related complications. The network meta-analysis was performed to adjust for indirect comparison and mixed treatment analysis.

Results

7 studies enroll a total of 456 patients who received different nutritional supports including parenteral nutrition (PN), enteral nutrition (EN), and PN + EN. No effects on in-hospital mortality (Median RR = 1.06, 95% Crl = 0.12 to 1.77) and the value of 0-1 days of serum albumin were found between the included regimens. However, the value of 11-13 days of serum albumin of EN was better than that of PN (WMD = -4.95, 95% CI = -7.18 to -2.72, P < 0.0001, I ² = 0%), and 16-20 days of serum albumin of EN + PN was better than that of EN (WMD = -7.42, 95% CI = -14.51 to -0.34, P=0.04, I ² = 90%). No effects on the 5-7 day nitrogen balance were found between the included regimens. In addition, the complications including pneumonia and sepsis have no statistical difference between EN and PN. EN was superior to PN in terms of LOS in the ICU and the incidence rate of stress ulcers. Although the difference in indirect comparisons between the included regimens was not statistically significant, the results showed that PN seemed to rank behind other regimens, and the difference between them was extremely small.

Conclusion

Available evidence suggests that EN + PN appears to be the most effective strategy for patients with TBI in improving clinical outcomes and nutritional support compared with other nutritional supports. Further trials are required.

Development of a prediction model for enteral feeding intolerance in intensive care unit patients: A prospective cohort study

BACKGROUND

Enteral nutrition (EN) is essential for critically ill patients. However, some patients will have enteral feeding intolerance (EFI) in the process of EN.

AIM

To develop a clinical prediction model to predict the risk of EFI in patients receiving EN in the intensive care unit.

METHODS

A prospective cohort study was performed. The enrolled patients’ basic information, medical status, nutritional support, and gastrointestinal (GI) symptoms were recorded. The baseline data and influencing factors were compared. Logistic regression analysis was used to establish the model, and the bootstrap resampling method was used to conduct internal validation.

RESULTS

The sample cohort included 203 patients, and 37.93% of the patients were diagnosed with EFI. After the final regression analysis, age, GI disease, early feeding, mechanical ventilation before EN started, and abnormal serum sodium were identified. In the internal validation, 500 bootstrap resample samples were performed, and the area under the curve was 0.70 (95%CI: 0.63-0.77).

CONCLUSION

This clinical prediction model can be applied to predict the risk of EFI.

N-methyl-D-aspartate receptor antagonists in improving cognitive deficits following traumatic brain injury: a systematic review

OBJECTIVE

To review the role of N-methyl-D-aspartate receptor (NMDAR) antagonists in managing post-TBI cognitive deficits.

METHODS

A search of PubMed, Embase, and Cochrane was conducted on Jan 12, 2021 without publication date or language restriction.

RESULTS

Forty-seven studies were included, involving 20 (42.6%) randomized controlled trials. Four (8.5%) studies had a low risk of bias (RoB), while 34 (72.3%) had unclear and nine (19.2%) had high RoB. Six NMDAR antagonists had been investigated: amantadine (n = 32), memantine (n = 4), magnesium (n = 4), traxoprodil (n = 3), selfotel (n = 2), and dextromethorphan (n = 2).

CONCLUSION

Although some benefits were observed, there are still some concerns regarding the efficacy and safety of NMDAR antagonists in improving post-TBI cognitive deficits. Further research is required to examine whether (i) these agents, notably amantadine, could accelerate cognitive improvement and shorten the hospital stay, (ii) these agents affect different cognitive domains/subdomains in the same direction, (iii) an optimal therapeutic time window exists, (iv) a member of this drug class can be proved to be effective without interfering in non-excitotoxic actions of glutamate, (v) they can be more effective as part of combination therapies or in particular subgroups of patients with TBI.

Traumatic Brain Injury Induces Gastrointestinal Dysfunction and Dysbiosis of Gut Microbiota Accompanied by Alterations of Bile Acid Profile

Gastrointestinal dysfunction is a common peripheral organ complication after traumatic brain injury (TBI), yet the underlying mechanism remains unknown. TBI has been demonstrated to cause gut microbiota dysbiosis in animal models, although the impacts of gut microbiota dysbiosis on gastrointestinal dysfunction were not examined. Bile acids are key metabolites between gut microbiota and host interactions. Therefore, the aim of this study was to investigate the mechanistic links between them by detecting the alterations of gut microbiota and bile acid profile after TBI. For that, we established TBI in mice using a lateral fluid percussion injury model. Gut microbiota was examined by 16S rRNA sequencing, and bile acids were profiled by ultra-performance liquid chromatography-tandem mass spectrometry. Our results showed that TBI caused intestinal inflammation and gut barrier impairment. Alterations of gut microbiota and bile acid profile were observed. The diversity of gut microbiota experienced a time dependent change from 1 h to 7 days post-injury. Levels of bile acids in feces and plasma were decreased after TBI, and the decrease was more significant in secondary bile acids, which may contribute to intestinal inflammation. Specific bacterial taxa such as Staphylococcus and Lachnospiraceae that may contribute to the bile acid metabolic changes were identifed. In conclusion, our study suggested that TBI-induced gut microbiota dysbiosis may contribute to gastrointestinal dysfunction via altering bile acid profile. Gut microbiota may be a potential treatment target for TBI-induced gastrointestinal dysfunction.

Gastrointestinal Complications in Critically Ill Children: Experience from A Resource-Limited Country

Objectives:

To determine the frequency and predictors of outcome of gastrointestinal complications (GIC) in critically ill children.

Methods:

This descriptive study was prospectively conducted in The Pediatric Intensive Care Unit (PICU), The Aga Khan University Hospital (AKUH), Karachi, from September 2015 to January 2017. After obtaining approval from the Ethical Review Committee of AKUH and informed consent from the parents, all children (aged one month to 18 years), of either gender, admitted to the Pediatric Intensive Care Unit (PICU) during the study period were included. The frequency of the defined GIC: vomiting, high gastric residue volume (GRV), diarrhea, constipation, and gastrointestinal bleed were recorded daily for the first week of the PICU stay. The data was collected by the primary investigator on a predesigned data collection form with inclusion of variables and predictors in light of existing literature and local expertise. The questionnaire was shared with the Pediatric Critical Care Medicine faculty and a consensus was sought on the elements to be incorporated.

Results:

GIC developed within the first 48 hours of admission in 78 (41%) patients. Of the patients who developed GIC, 37 (47.4%) patients developed high GRV: 31 (39.7%) patients developed constipation, 18 (23.1%) patients developed vomiting, 14 (17.9%) patients developed abdominal distension. With regards to prevalence by occurrence, 32/78 (41%) of patients presented with two GI complications, followed by 21 patients (27%) who presented with a single GIC. Only 11 patients (14%) presented with more than three complications. Median length of stay was higher in patients with GIC (8 days) than with those who did not develop GIC (4 days). The frequency of gastrointestinal complications was significantly higher in children receiving mechanical ventilation, on sedatives and relaxants and those with multiorgan dysfunction syndrome (MODS) and inotropes

Conclusion:

GI complications are a frequent occurrence in the PICU and are associated with worse clinical outcomes. The use of sedative drugs and the presence of shock with MODS were amongst the important contributing factors.

Bidirectional Brain-Systemic Interactions and Outcomes After TBI

Traumatic brain injury (TBI) is a debilitating disorder associated with chronic progressive neurodegeneration and long-term neurological decline. Importantly, there is now substantial and increasing evidence that TBI can negatively impact systemic organs, including the pulmonary, gastrointestinal (GI), cardiovascular, renal, and immune system. Less well appreciated, until recently, is that such functional changes can affect both the response to subsequent insults or diseases, as well as contribute to chronic neurodegenerative processes and long-term neurological outcomes. In this review, we summarize evidence showing bidirectional interactions between the brain and systemic organs following TBI and critically assess potential underlying mechanisms.

Semi-elemental versus polymeric formula for enteral nutrition in brain-injured critically ill patients: a randomized trial

Background

The properties of semi-elemental enteral nutrition might theoretically improve gastrointestinal tolerance in brain-injured patients, known to suffer gastroparesis. The purpose of this study was to compare the efficacy and tolerance of a semi-elemental versus a polymeric formula for enteral nutrition (EN) in brain-injured critically ill patients.

Methods

Prospective, randomized study including brain-injured adult patients [Glasgow Coma Scale (GCS) ≤ 8] with an expected duration of mechanical ventilation > 48 h. Intervention: an enteral semi-elemental (SE group) or polymeric (P group) formula. EN was started within 36 h after admission to the intensive care unit and was delivered according to a standardized nurse-driven protocol. The primary endpoint was the percentage of patients who received both 60% of the daily energy goal at 3 days and 100% of the daily energy goal at 5 days after inclusion. Tolerance of EN was assessed by the rate of gastroparesis, vomiting and diarrhea.

Results

Respectively, 100 and 95 patients were analyzed in the SE and P groups: Age (57[44–65] versus 55[40–65] years) and GCS (6[3–7] versus 5[3–7]) did not differ between groups. The percentage of patients achieving the primary endpoint was similar (46% and 48%, respectively; relative risk (RR) [95% confidence interval (CI)] = 1.05 (0.78–1.42); p = 0.73). The mean daily energy intake was, respectively, 20.2 ± 6.3 versus 21.0 ± 6.5 kcal/kg/day (p = 0.42). Protein intakes were 1.3 ± 0.4 versus 1.1 ± 0.3 g/kg/day (p < 0.0001). Respectively, 18% versus 12% patients presented gastroparesis (p = 0.21), and 16% versus 8% patients suffered from diarrhea (p = 0.11). No patient presented vomiting in either group.

Conclusion

Semi-elemental compared to polymeric formula did not improve daily energy intake or gastrointestinal tolerance of enteral nutrition.

Trial registration

EudraCT/ID-RCB 2012-A00078-35 (registered January 17, 2012).

Acute colitis during chronic experimental traumatic brain injury in mice induces dysautonomia and persistent extraintestinal, systemic, and CNS inflammation with exacerbated neurological deficits

BACKGROUND

Disruptions of brain-gut axis have been implicated in the progression of a variety of gastrointestinal (GI) disorders and central nervous system (CNS) diseases and injuries, including traumatic brain injury (TBI). TBI is a chronic disease process characterized by persistent secondary injury processes which can be exacerbated by subsequent challenges. Enteric pathogen infection during chronic TBI worsened cortical lesion volume; however, the pathophysiological mechanisms underlying the damaging effects of enteric challenge during chronic TBI remain unknown. This preclinical study examined the effect of intestinal inflammation during chronic TBI on associated neurobehavioral and neuropathological outcomes, systemic inflammation, and dysautonomia.

METHODS

Dextran sodium sulfate (DSS) was administered to adult male C57BL/6NCrl mice 28 days following craniotomy (Sham) or TBI for 7 days to induce intestinal inflammation, followed by a return to normal drinking water for an additional 7 to 28 days for recovery; uninjured animals (Naïve) served as an additional control group. Behavioral testing was carried out prior to, during, and following DSS administration to assess changes in motor and cognitive function, social behavior, and mood. Electrocardiography was performed to examine autonomic balance. Brains were collected for histological and molecular analyses of injury lesion, neurodegeneration, and neuroinflammation. Blood, colons, spleens, mesenteric lymph nodes (mLNs), and thymus were collected for morphometric analyses and/or immune characterization by flow cytometry.

RESULTS

Intestinal inflammation 28 days after craniotomy or TBI persistently induced, or exacerbated, respectively, deficits in fine motor coordination, cognition, social behavior, and anxiety-like behavior. Behavioral changes were associated with an induction, or exacerbation, of hippocampal neuronal cell loss and microglial activation in Sham and TBI mice administered DSS, respectively. Acute DSS administration resulted in a sustained systemic immune response with increases in myeloid cells in blood and spleen, as well as myeloid cells and lymphocytes in mesenteric lymph nodes. Dysautonomia was also induced in Sham and TBI mice administered DSS, with increased sympathetic tone beginning during DSS administration and persisting through the first recovery week.

CONCLUSION

Intestinal inflammation during chronic experimental TBI causes a sustained systemic immune response and altered autonomic balance that are associated with microglial activation, increased neurodegeneration, and persistent neurological deficits.

Therapeutic Effect of Enteral Nutrition Supplemented with Probiotics in the Treatment of Severe Craniocerebral Injury: A Systematic Review and Meta-Analysis

BACKGROUND

Whether early enteral nutrition with probiotics can reduce the mortality and infection rate of patients with severe craniocerebral injury (SCI), improve their gastrointestinal function, and shorten the length of stay in the intensive care unit (ICU) has not been determined.

METHODS

PubMed, China National Knowledge Infrastructure, and Embase were electronically searched for the purpose of identifying randomized controlled trials investigated the potential of early enteral nutrition supplemented with probiotics on patients with SCI from the establishment of databases to August 26, 2019. STATA software version 12.0 was used to perform meta-analysis.

RESULTS

A total of 39 trials enrolling 3387 patients were included. Early enteral nutrition supplemented with probiotics was associated with decreased risk of infection (pooled risk ratio [RR], 0.486; 95% confidence interval [CI], 0.394-0.599), decreased risk of 7-, 14-, and 28-day mortality (pooled RRs, 0.415, 0.497, and 0.385; 95% CIs, 0.196-0.878, 0.297-0.833, and 0.197-0.751, respectively), and decreased risk of gastrointestinal complications (pooled RR, 0.363; 95% CI, 0.274-0.481). It also shortened the time course recovery of enteral function and shortened the length of stay in hospital and length of ICU stay (standardized mean differences, -3.327 and -1.461; 95% CIs, -6.213 to -0.440 and -2.111 to -0.811, respectively).

CONCLUSIONS

Enteral nutrition supplemented with probiotics effectively decreases the risk of mortality, gastrointestinal complications, and infection, and shortens the stays in ICU; therefore, it should be extensively adopted to manage these given patients.

Nutritional and metabolic supplementation for the injured brain: an update

PURPOSE OF REVIEW

Energy dysfunction is increasingly recognized as a key factor in the pathogenesis of acute brain injury (ABI). This one characterized by a high metabolic rate and nitrogen loss is often associated with an undernutrition support. We review the metabolism evolution and nutritional status in brain injured patient and summarize evidence on nutritional support in this condition.

RECENT FINDINGS

The role of nutrition support for improving prognosis in brain injured patient has been underlined recently. A fast nutrition institution whatever the route is essential to prevent an imbalance in caloric support. Moreover, hypermetabolic state must be prevented with a sufficient nitrogen support. Glycemic control is particularly relevant in this group of patient, with the discovery of new fuel that could potentially improve cerebral metabolism and replace glucose. Few data support also the use of immunonutrition input in this group of patients.

SUMMARY

Nutritional support is a key parameter in brain injured patient and must be initiated quickly to counteract hypermetabolic state by caring to improve caloric and nitrogen input. Recent clinical data support the use of immunonutrition, glutamine and zinc in this particular setting.

Alterations in Peripheral Organs following Combined Hypoxemia and Hemorrhagic Shock in a Rat Model of Penetrating Ballistic-Like Brain Injury

Polytrauma, with combined traumatic brain injury (TBI) and systemic damage are common among military and civilians. However, the pathophysiology of peripheral organs following polytrauma is poorly understood. Using a rat model of TBI combined with hypoxemia and hemorrhagic shock, we studied the status of peripheral redox systems, liver glycogen content, creatinine clearance, and systemic inflammation. Male Sprague-Dawley rats were subjected to hypoxemia and hemorrhagic shock insults (HH), penetrating ballistic-like brain injury (PBBI) alone, or PBBI followed by hypoxemia and hemorrhagic shock (PHH). Sham rats received craniotomy only. Biofluids and liver, kidney, and heart tissues were collected at 1 day, 2 days, 7 days, 14 days, and 28 days post-injury (DPI). Creatinine levels were measured in both serum and urine. Glutathione levels, glycogen content, and superoxide dismutase (SOD) and cytochrome C oxidase enzyme activities were quantified in the peripheral organs. Acute inflammation marker serum amyloid A-1 (SAA-1) level was quantified using western blot analysis. Urine to serum creatinine ratio in PHH group was significantly elevated on 7-28 DPI. Polytrauma induced a delayed disruption of the hepatic GSH/GSSG ratio, which resolved within 2 weeks post-injury. A modest decrease in kidney SOD activity was observed at 2 weeks after polytrauma. However, neither PBBI alone nor polytrauma changed the mitochondrial cytochrome C oxidase activity. Hepatic glycogen levels were reduced acutely following polytrauma. Acute inflammation marker SAA-1 showed a significant increase at early time-points following both systemic and brain injury. Overall, our findings demonstrate temporal cytological/tissue level damage to the peripheral organs due to combined PBBI and systemic injury.

Insights into the Authentic Active Ingredients and Action Sites of Oral Exogenous Glutathione in the Treatment of Ischemic Brain Injury Based on Pharmacokinetic-Pharmacodynamic Studies

Glutathione (GSH) has been reported to be closely related to various diseases of the central nervous system, yet its authentic active ingredients and action sites remain unclear. In the present study, oral exogenous GSH significantly alleviated ischemic brain injury, but this result was inconsistent with its low bioavailability and blood-brain barrier (BBB) permeability. To ascertain the exposure of GSH-derived ingredients, including GSH, cysteine (CYS), glutamate (Glu), glycine (GLY), CYS-GLY, and γ-glutamylcysteine (γ-GC) were systematically studied both in vitro and in vivo. The outcomes demonstrated that oral GSH not only increases the GSH and CYS levels in rat striatum and cortex, but it also can decrease the rise of intracerebral Glu concentration caused by ischemia/reperfusion surgery. Then the influence of GSH on the BBB was investigated via measuring IgG leakage, intracerebral endotoxin, and tight-junction proteins. All indicators showed that GSH dosing can repair the destroyed BBB. Oral GSH greatly enhances the exposure of GSH, CYS, CYS-GLY, and γ-GC in rat duodenum, jejunum, ileum, and colon. Accumulating evidence reveals a close link between brain injury and gastrointestinal dysfunction. Our findings further suggest that oral GSH significantly improves intestinal inflammatory damage and barrier disruptions. In conclusion, oral GSH can have a direct therapeutic role in brain injury by stabilizing intracerebral levels of GSH, CYS, and Glu. It can also play an indirect therapeutic role by enhancing the intestinal exposure of GSH, CYS, CYS-GLY, and γ-GC and improving intestinal barrier disruptions. SIGNIFICANCE STATEMENT: The authentic active ingredients and action sites of exogenous glutathione (GSH) in the treatment of ischemic brain injury are unclear. We have shown that oral exogenous GSH not only stabilizes intracerebral levels of GSH, cysteine (CYS), and glutamate (Glu) to act directly on brain injury, but it can also exert an indirect therapeutic role by improving intestinal barrier disruptions. These findings have great significance for revealing the therapeutic effect of GSH on ischemic brain injury and for promoting its further development and clinical application.

Status and nutritional therapy in elective and emergency neurosurgery patients

OBJEVECT

To evaluate the Nutritional Status (NS) and follow the Enteral Nutritional Therapy (ENT) of patients in neurosurgical intervention.

METHOD

Cohort study in emergency or elective surgery patients with exclusive ENT. Anthropometric measurements (Arm Circumference (AC and Triceps Skinfold (TSF)) were measured on the first, seventh and 14th day. For the ENT monitoring, caloric/protein adequacy, fasting, inadvertent output of the enteral probe and residual gastric volume were used.

RESULTS

80 patients, 78.7% in emergency surgery and 21.3% in elective surgery. There was a reduction in AC and Body Mass Index (BMI) (p>0.01), especially for the emergency group. The caloric/protein adequacy was higher in the emergency group (86.7% and 81.8%).

CONCLUSION

The EN change was greater in the emergency group, even with better ENT adequacy. Changes in body composition are frequent in neurosurgical patients, regardless of the type of procedure.

Early enteral nutrition supplemented with probiotics improved the clinical outcomes in severe head injury: Some promising findings from Chinese patients

BACKGROUND

The role of early enteral nutrition (ENN) supplemented with probiotics (<48 hours) in improving clinical outcomes of patients with severe head injury (SHI) remains controversial. We performed this meta-analysis to investigate the efficacy of EEN supplemented with probiotics on clinical outcomes in these patients.

METHODS

Systematic searches were performed in PubMed, Cochrane Central Register of Controlled Trials, China National Knowledge Infrastructure, Wanfang database, and Chinese Biomedical Literature to identify potential studies. Two investigators checked citations, extracted data, appraised risk of bias, and then STATA 12.0 was used to perform statistical analysis.

RESULTS

A total of 18 trials were eventually included in the present study. Meta-analysis indicated that EEN supplemented with probiotics was associated with decreased risk of infection (risk ratio [RR], 0.53; 95% confidence interval [CI], 0.44-0.65), decreased risk of mortality (RR, 0.56; 95% CI, 0.38-0.82), decreased risk of gastrointestinal complications (RR, 0.19; 95% CI, 0.13-0.25), and shortened stays in intensive care unit (ICU) (mean difference [MD], -4.55; 96% CI, -5.91 to -3.19).

CONCLUSION

EEN supplemented with probiotics may be a promising alternative for patients with SHI because it effectively decreased the risk of infection, mortality, and gastrointestinal complications, as well as shortened the stays in ICU.

Incidence of diarrhea and associated risk factors in patients with traumatic brain injury and enteral nutrition

To determine the occurrence of diarrhea and associated factors in critically ill patients with traumatic brain injury (TBI) in use of nutritional therapy. Prospective cohort study conducted in an Intensive Care Unit (ICU) of a General Hospital reference in trauma. We evaluated TBI patients who stayed less than 72 h in the ICU, who were using EN for at least 48 h. Definition of diarrhea it was considered three or more episodes of liquid stools or semi-liquid at 24 h. For analysis were evaluated demographic, epidemiological, clinical and nutritional data. Twenty-three patients were evaluated, being 86.9% male, median 33 years old (IQR = 25-52 years) and 16-day ICU stay (IQR = 10-26 days). Diarrhea occurred in 69.6% of the patients and they had a longer time in the ICU (p = 0.007). All patients who used combination prokinetic therapy (metoclopramide and erythromycin) and used antibiotics for more than 8 days had diarrhea (p = 0.057 and p = 0.007, respectively). The incidence of diarrhea was high in TBI patients with enteral nutrition and was associated with the use of antibiotics for more than one week.

A more physiological feeding process in ICU: Intermittent infusion with semi-solid nutrients (CONSORT-compliant)

INTRODUCTION AND OBJECTIVES

The goal of this study is to determine whether the application of semi-solid nutrients could increase the efficiency of the enteral nutrition (EN), which was measured daily by administered volume of nutrition/prescribed volume of nutrition.

METHODS

A total of 28 subjects were finally enrolled in the study and randomized to receive either intermittent feeding (IF) or intermittent feeding with semi-solid nutrients (IS). Three major parameters concerning EN were evaluated in this study: the daily dosage prescribed by doctor, the actual dosage received by subjects, and the acute complications such as diarrhea, vomiting, regurgitation, bowel distension, and lung infection.

RESULTS

There were no statistical differences in NRS-2002, and acute gastrointestinal injury between both groups. The IS group (0.98 ± 0.06, P < .01) could receive higher percentage of daily prescribed calories compared to IF (0.73 ± 0.15). The total caloric intake during the first 3 days was higher in IS (2589.29 ± 844.02 vs. 1685.71 ± 388.00, P < .01). The incidence of feeding intolerance (FI) was lower in the IS group (2/14) compared with IF (8/14). However, semi-solid nutrients did not decrease the length of stay, lung infection, or 30-day mortality. Similarly, there was no difference in glycemic variability and stress hyperglycemia.

CONCLUSIONS

In our cohort of critically ill subjects, the efficiency of the EN was increased by IS, which might be related to the improvement of FI (NCT03017079).

Identification of risk factors for enteral feeding intolerance screening in critically ill patients

Objectives:

To identify risk factors for enteral feeding intolerance screening in critically ill patients, thereby, provide some reference for healthcare staff to assess the risk of feeding intolerance, and lay the foundation for future scale development.

Methods:

This study used a mixed methodology, including a literature review, semi-structured interviews, the Delphi technique, and the analytic hierarchy process. We used the literature review and semi-structured interviews (n=22) to draft a preliminarily item pool for feeding intolerance, Delphi technique (n=30) to screen and determine the items, and the analytic hierarchy process to calculate the weight of each item. The study was conducted between June 2014 and September 2015 in Daping Hospital, Third Military Medical University, Chongqing, China.

Results:

Twenty-three risk factors were selected for the scale, including 5 dimensions. We assigned a weight to each item according to their impact on the feeding intolerance, with a higher score indicating a greater impact. The weight of each dimension was decreasing as follows: patient conditions, weight score equals 42; general conditions, weight score equals 23; gastrointestinal functions, weight score equals 15; biochemical indexes, weight score equals 14; and treatment measures, weight score equals 6.

Conclusion:

Developed list of risk factors based on literature review, survey among health care professionals and expert consensus should provide a basis for future studies assessing the risk of feeding intolerance in critically ill patients.

Changes in the dysphagia and nutritional status of patients with brain injury

AIMS AND OBJECTIVES

To evaluate the degree of improvement in the dysphagia and nutritional status of patients with brain injuries after removal of the nasogastric tube.

BACKGROUND

The nurse should assess patients' dysphagia, after removal of the nasogastric tube, and immediately reflect the changes in patient care. Accordingly, the critical roles of nurses in caring for patients with dysphagia involve providing appropriate nutritional therapy as well as preventing aspiration pneumonia and nutritional imbalance. Assessment of the patient's dysphagia on a regular basis and analysis of nutritional status according to the degree of dysphagia are necessary to determine the appropriate timing for providing nursing interventions and to develop protocols for the provision of a therapeutic diet.

DESIGN

Prospective observational study.

METHODS

This study was conducted on 56 patients with dysphagia after a brain injury. Data were collected using the Gugging Swallowing Screen (GUSS) test and Swallowing Symptom Questionnaire (SSQ). Descriptive statistics, chi-square tests, t tests, and MANOVA were analysed using SPSS 22.0.

RESULTS

Patient's dysphagia was observed over the course of 2 weeks. After 14 days, the severity of dysphagia decreased from 91.1%-35.7%, while the number of participants with normal swallowing increased from 1.8%-58.9%. Dysphagia in patients with brain injury improved gradually over time. A significant difference was observed in the serum albumin level of patients with dysphagia (F = 9.51, p = .003, Wilk's λ = .034).

CONCLUSIONS

Most of the patients with brain injury developed moderate dysphagia immediately after removal of the nasogastric tube. However, after 14 days had elapsed, the percentage of patients recovering from dysphagia increased to 58.9%. Proper dietary patterns were not adequately provided depending on the degree of patient's dysphagia after removal of the nasogastric tube. Assessing the degree of dysphagia using the GUSS test and providing appropriate diet prevent malnutrition in patients with dysphagia.

RELEVANCE TO CLINICAL PRACTICE

This study was conducted in patients who developed complications of dysphagia after a brain injury. Using the Gugging Swallowing Screen (GUSS) test, the changes in the degree of dysphagia were repeatedly measured at different times: 4, 7 and 14 days after the removal of the nasogastric tube. Provision of appropriate diet and changes in the nutritional status were analysed to determine the proper timing for nursing intervention in patients with dysphagia. The data obtained from this study could serve as a basis for developing diet provision protocols for patients with dysphagia.

Barriers to Nutrition Intervention for Patients With a Traumatic Brain Injury: Views and Attitudes of Medical and Nursing Practitioners in the Acute Care Setting

BACKGROUND

Nutrition delivered to patients with a traumatic brain injury (TBI) is typically below prescribed amounts. While the dietitian plays an important role in the assessment and provision of nutrition needs, they are part of a multidisciplinary team. The views and attitudes of medical and nursing practitioners are likely to be crucial to implementation of nutrition to patients with TBI, but there is limited information describing these.

METHODS

A qualitative exploratory approach was used to explore the views and attitudes of medical and nursing practitioners on nutrition for patients with TBI. Participants at 2 major neurotrauma hospitals in Australia completed individual semi-structured interviews with a set of questions and a case study. Interviews were transcribed and coded for themes.

RESULTS

Thirty-four health practitioners participated: 18 nurses and 16 physicians. Three major themes emerged: (1) nutrition practices over the hospital admission reflect the recovery course, (2) there are competing priorities when caring for patients with TBI, and (3) the implementation of nutrition therapy is influenced by practitioner roles and expectations.

CONCLUSION

Use of qualitative inquiry in the study of attitudes toward nutrition provision to patients with TBI provided detailed insights into the challenges of operationalizing nutrition therapy. These insights can be used to clarify communication between health practitioners working with patients with TBI across the continuum of care.

Bidirectional brain-gut interactions and chronic pathological changes after traumatic brain injury in mice

OBJECTIVES

Traumatic brain injury (TBI) has complex effects on the gastrointestinal tract that are associated with TBI-related morbidity and mortality. We examined changes in mucosal barrier properties and enteric glial cell response in the gut after experimental TBI in mice, as well as effects of the enteric pathogen Citrobacter rodentium (Cr) on both gut and brain after injury.

METHODS

Moderate-level TBI was induced in C57BL/6mice by controlled cortical impact (CCI). Mucosal barrier function was assessed by transepithelial resistance, fluorescent-labelled dextran flux, and quantification of tight junction proteins. Enteric glial cell number and activation were measured by Sox10 expression and GFAP reactivity, respectively. Separate groups of mice were challenged with Cr infection during the chronic phase of TBI, and host immune response, barrier integrity, enteric glial cell reactivity, and progression of brain injury and inflammation were assessed.

RESULTS

Chronic CCI induced changes in colon morphology, including increased mucosal depth and smooth muscle thickening. At day 28 post-CCI, increased paracellular permeability and decreased claudin-1 mRNA and protein expression were observed in the absence of inflammation in the colon. Colonic glial cell GFAP and Sox10 expression were significantly increased 28days after brain injury. Clearance of Cr and upregulation of Th1/Th17 cytokines in the colon were unaffected by CCI; however, colonic paracellular flux and enteric glial cell GFAP expression were significantly increased. Importantly, Cr infection in chronically-injured mice worsened the brain lesion injury and increased astrocyte- and microglial-mediated inflammation.

CONCLUSION

These experimental studies demonstrate chronic and bidirectional brain-gut interactions after TBI, which may negatively impact late outcomes after brain injury.

Traumatic stress-induced persistent changes in DNA methylation regulate neuropeptide Y expression in rat jejunum

BACKGROUND

Stress-induced chronic neuropsychiatric conditions such as anxiety are often co-morbid with gastrointestinal malfunctions. While we find enduring anxiety-like symptoms following minimal traumatic brain injury (MTBI) in rats, gastrointestinal consequences of MTBI remain elusive.

METHODS

In this study, we examined the effects of MTBI on a major gut peptide, neuropeptide Y (NPY) and gut motility. DNA methylation was studied as a possible epigenetic mechanism operative in the regulation of NPY expression in the gut.

KEY RESULTS

Minimal traumatic brain injury reduced the gut motility 48 hours and 30 days after trauma. The expression of DNA methyltransferase isoforms (DNMT1, DNMT3a, and DNMT3b) was altered in the jejunum 48 hours and 30 days after MTBI. However, the mRNA levels of growth arrest and DNA damage 45 (GADD45) isoforms, GADD45a, and GADD45b, which are believed to be involved in active DNA demethylation, initially decreased at 48 hours but subsequently increased after 30 days of trauma. Similarly, DNA hypomethylation at the NPY promoter region in the jejunum was correlated with the increase in NPY mRNA and protein levels 30 days post-trauma. On the other hand, DNA hypomethylation at 48 hours was associated with a decline in NPY expression. Treatment with 5-azacytidine (5-AzaC), a DNMT inhibitor, retarded DNA methylation and restored the NPY mRNA levels in the jejunum of MTBI-induced rats.

CONCLUSIONS & INFERENCES

These results suggest that DNA demethylation could be operative as an epigenetic mechanism in the long-term regulation of NPY gene expression to alter the gut motility during traumatic stress.

Kinked and retained nasogastric tube in polytrauma patient; a case report

Enteral feeding is an important and preferred technique of feeding in head injury patient to provide nutrition. As inadequate nutrition causes decrease in physical ability, neurological impairment and takes a long time for improvement or delayed deterioratation. With our best knowledge kinked and retained nasogastric tube in stomach is a very rare complication of feeding in head injuries patients. Predisposing factors that can cause kinking is excess tube length, tube in situ for long time and small bore tube. We are reporting one such case of kinked and retained nasogastric tube in the stomach of a polytrauma patient which was retrieved by upper GI endoscope.

Effects of Synbiotic2000™ Forte on the Intestinal Motility and Interstitial Cells of Cajal in TBI Mouse Model

The main objective of this study was to investigate the effects of Synbiotic2000™ Forte on the intestinal motility and interstitial cells of Cajal (ICC) in traumatic brain injury (TBI) mouse model. Kunming mice were randomly divided into sham operation group (S group), enteral nutrition group with TBI (E group), and Synbiotic2000™ Forte group with TBI (P group). The contractile activity of the intestinal smooth muscle, densities and ultrastructure of the ICC, kit protein concentration, weight, and defecation of mice were monitored and analyzed. TBI markedly suppressed contractile activity of the intestinal smooth muscle (P < 0.01), which led to a reduction of defecation (P < 0.01) and weight (P < 0.01). However, application of Synbiotic2000™ Forte significantly improved contractile activity of the small intestine (P < 0.01), which may be related to protective effects to the interstitial cells of Cajal, smooth muscle cells, and enteric neurons. TBI impaired ICC networks and densities (P < 0.01), events that were protected by the application of Synbiotic2000™ Forte. Synbiotic2000™ Forte may attenuate TBI-mediated inhibition of the kit protein pathway. Synbiotic2000™ Forte may improve intestinal motility and protect the ICC in the TBI mouse. These findings provide a novel support for the application of Synbiotic2000™ Forte in intestinal motility disturbance after TBI.

Early Enteral Combined with Parenteral Nutrition Treatment for Severe Traumatic Brain Injury: Effects on Immune Function, Nutritional Status and Outcomes

Objective To compare the conjoint effect of enteral nutrition (EN) and parenteral nutrition (PN) with single EN or PN on immune function, nutritional status, complications and clinical outcomes of patients with severe traumatic brain injury (STBI). Methods A prospective randomized control trial was carried out from January 2009 to May 2012 in Neurological Intensive Care Unit (NICU). Patients of STBI who met the enrolment criteria (Glasgow Coma Scale score 6~8; Nutritional Risk Screening ≥3) were randomly divided into 3 groups and were admi- nistrated EN, PN or EN+PN treatments respectively. The indexes of nutritional status, immune function, complications and clinical outcomes were examined and compared statistically. Results There were 120 patients enrolled in the study, with 40 pationts in each group. In EN+PN group, T lymthocyte subsets CD3+%, CD4+%, ratio of CD3+/CD25+, ratio of CD4+/CD8+, the plasma levels of IgA, IgM, and IgG at 20 days after nutritional treatment were significantly increased compared to the baseline(t=4.32-30.00, P<0.01), and they were significantly higher than those of PN group (t=2.44-14.70; P<0.05,or P<0.01) with exception of CD4+/CD8+, higher than those of EN group (t=2.49-13.31, P<0.05, or P<0.01) with exceptions of CD3+/CD25+, CD4+/CD8+, IgG and IgM. For the nutritional status, the serum total protein, albumin, prealbumin and hemoglobin were significantly higher in the EN (t=5.87-11.91; P<0.01) and EN+PN groups (t=6.12-13.12; P<0.01) than those in PN group after nutrition treatment. The serum prealbumin was higher in EN+PN group than that in EN group (t=2.08; P<0.05). Compared to the PN group, the complication occurrence rates of EN+PN group were significantly lower in stress ulcer (22.5% vs. 47.5%; χ²= 8.24, P<0.01), intracranial infection (12.5% vs 32.5%;χ²= 6.88, P<0.01) and pyemia (25.0% vs. 47.5%; χ²= 6.57, P<0.05). Compared to the EN group, the complication occurrence rates of EN+PN group were significantly lower in aspirated pneumonia (27.5% vs. 50.0%; χ²= 6.39, P<0.05), hypoproteinemia (17.5% vs. 55.0%; χ²= 18.26, P<0.01) and diarrhea (20.0% vs. 60.0%; χ²= 20.00, P<0.01). The EN+PN group also had significant less length of stay in NICU (t=2.51, 4.82; P<0.05, P<0.01), number of patients receiving assisted mechanical ventilation (χ²= 6.08, 12.88; P<0.05, P<0.01) and its durations (t=3.41, 9.08; P<0.05, P<0.01), and the death rate (χ²=7.50, 16.37; P<0.05, P<0.01) than those of EN or PN group. Conclusion Early EN+PN treatment could promote the recovery of the immune function, enhance nutritional status, decrease complications and improve the clinical outcomes in patients with severe traumatic brain injury.

The impact of measurement of respiratory quotient by indirect calorimetry on the achievement of nitrogen balance in patients with severe traumatic brain injury

BACKGROUND

This study evaluated the impact of IC on the optimization of nutritional support and the achievement of +NB in patients with TBI.

MATERIALS AND METHODS

27 patients (GCS ≤ 8), treated with a 5-day multimodality monitoring and goal-directed therapy protocol, received enteral nutrition on day 1 followed by IC on days 3 and 5 and assessment of NB on day 7. In the first cohort (n = 11), no adjustment in kcal was made. In the second cohort (n = 16), nutrition was targeted to an RQ of 0.83 by day 3. The first cohort was analyzed with respect to NB status; the second cohort was compared to patients with (-) and +NB of the first cohort. Data (mean ± SD) were analyzed with unpaired t test, and Chi square and Fisher exact tests.

RESULTS

4/11(36 %) patients in the first cohort had +NB. The predicted mortality by TRISS, substrate utilization, and RQ was significantly lower compared to the second cohort. The mortality predicted by the CrasH model did not differ between the two cohorts. A RQ of 0.74 was associated with the preferential use of fat and protein and -NB, whereas a RQ of 0.84 favored utilization of carbohydrates and +NB. All patients whose kcal intake was adjusted based on the RQ on day 3 reached a +NB by day 7.

CONCLUSION

An increase in kcal ≥25 % in patients with a RQ < 0.83 on day 3 improves substrate utilization, decreases protein utilization and optimizes the achievement of +NB by day 7.

Energy and protein deficits throughout hospitalization in patients admitted with a traumatic brain injury

BACKGROUND AND AIMS

Patients with traumatic brain injury (TBI) experience considerable energy and protein deficits in the intensive care unit (ICU) and these are associated with adverse outcomes. However, nutrition delivery after ICU discharge during ward-based care, particularly from oral diet, has not been measured. This study aimed to quantify energy and protein delivery and deficits over the entire hospitalization for critically ill TBI patients.

METHODS

Consecutively admitted adult patients with a moderate-severe TBI (Glasgow Coma Scale 3-12) over 12 months were eligible. Observational data on energy and protein delivered from all routes were collected until hospital discharge or day 90 and compared to dietician prescriptions. Oral intake was quantified using weighed food records on three pre-specified days each week. Data are mean (SD) unless indicated. Cumulative deficit is the mean absolute difference between intake and estimated requirements.

RESULTS

Thirty-seven patients [45.3 (15.8) years; 87% male; median APACHE II 18 (IQR: 14-22)] were studied for 1512 days. Median duration of ICU and ward-based stay was 13.4 (IQR: 6.4-17.9) and 19.9 (9.6-32.0) days, respectively. Over the entire hospitalization patients had a cumulative deficit of 18,242 (16,642) kcal and 1315 (1028) g protein. Energy and protein intakes were less in ICU than the ward (1798 (800) vs 1980 (915) kcal/day, p = 0.015; 79 (47) vs 89 (41) g/day protein, p = 0.001). Energy deficits were almost two-fold greater in patients exclusively receiving nutrition orally than tube-fed (806 (616) vs 445 (567) kcal/day, p = 0.016) while protein deficits were similar (40 (5) vs 37 (6) g/day, p = 0.616). Primary reasons for interruptions to enteral and oral nutrition were fasting for surgery/procedures and patient-related reasons, respectively.

CONCLUSIONS

Patients admitted to ICU with a TBI have energy and protein deficits that persist after ICU discharge, leading to considerable shortfalls over the entire hospitalization. Patients ingesting nutrition orally are at particular risk of energy deficit.

Nutrition support practices in critically ill head-injured patients: a global perspective

Background

Critical illness following head injury is associated with a hypermetabolic state but there are insufficient epidemiological data describing acute nutrition delivery to this group of patients. Furthermore, there is little information describing relationships between nutrition and clinical outcomes in this population.

Methods

We undertook an analysis of observational data, collected prospectively as part of International Nutrition Surveys 2007-2013, and extracted data obtained from critically ill patients with head trauma. Our objective was to describe global nutrition support practices in the first 12 days of hospital admission after head trauma, and to explore relationships between energy and protein intake and clinical outcomes. Data are presented as mean (SD), median (IQR), or percentages.

Results

Data for 1045 patients from 341 ICUs were analyzed. The age of patients was 44.5 (19.7) years, 78 % were male, and median ICU length of stay was 13.1 (IQR 7.9-21.6) days. Most patients (94 %) were enterally fed but received only 58 % of estimated energy and 53 % of estimated protein requirements. Patients from an ICU with a feeding protocol had greater energy and protein intakes (p <0.001, 0.002 respectively) and were more likely to survive (OR 0.65; 95 % CI 0.42-0.99; p = 0.043) than those without. Energy or protein intakes were not associated with mortality. However, a greater energy and protein deficit was associated with longer times until discharge alive from both ICU and hospital (all p <0.001).

Conclusion

Nutritional deficits are commonplace in critically ill head-injured patients and these deficits are associated with a delay to discharge alive.

Enteral Nutrition for Patients With Traumatic Brain Injury in the Rehabilitation Setting: Associations With Patient Preinjury and Injury Characteristics and Outcomes

OBJECTIVE

To determine the association of enteral nutrition (EN) with patient preinjury and injury characteristics and outcomes for patients receiving inpatient rehabilitation after traumatic brain injury (TBI).

DESIGN

Prospective observational study.

SETTING

Nine rehabilitation centers.

PARTICIPANTS

Patients (N=1701) admitted for first full inpatient rehabilitation after TBI.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

FIM at rehabilitation discharge, length of stay, weight loss, and various infections.

RESULTS

There were many significant differences in preinjury and injury characteristics between patients who received EN and patients who did not. After matching patients with a propensity score of >40% for the likely use of EN, patients receiving EN with either a standard or a high-protein formula (>20% of calories coming from protein) for >25% of their rehabilitation stay had higher FIM motor and cognitive scores at rehabilitation discharge and less weight loss than did patients with similar characteristics not receiving EN.

CONCLUSIONS

For patients receiving inpatient rehabilitation after TBI and matched on a propensity score of >40% for the likely use of EN, clinicians should strongly consider, when possible, EN for ≥25% of the rehabilitation stay and especially with a formula that contains at least 20% protein rather than a standard formula.

Nutritional status, assessment, requirements and adequacy of traumatic brain injury patients

Traumatic Brain Injury (TBI) has been considered as a serious public health problem. Each year, traumatic brain injuries are contributing to a substantial number of cases of permanent disability and deaths and it can be classified according to the severity into penetrating and closed head injury. Symptoms, beside to be unconscious can be defined as vomiting, nausea, headache, dizziness, lack of motor coordination, difficulty in balancing, blurred vision and lightheadedness, bad taste in the mouth, ringing in the ears, fatigue and lethargy as well as changes in sleep patterns. The brain is known to be the functional regulator for all the metabolic activities inside the body and TBI patients mostly have a complex metabolic alterations including aberrant cellular metabolism, abnormal metabolic processes, changes in hormones functions and inflammatory cascade. The TBI patient's status needed to be assessed medically and nutritionally since the medical status of the patients can affect the nutrition part. Data from the four assessment tools are needed to be correctly used and interpreted in order to make a proper nutritional diagnosis, clinical assessment, biochemistry as well as anthropometric measurements. Regardless the methods used for assessing TBI patients, having adequate intake and medical care can lead to a reduction in hospital costs, numbers of day hospitalized, numbers of hours of mechanical ventilation and in the overall infection rates.

The Effects of Lactobacillus acidophilus on the Intestinal Smooth Muscle Contraction through PKC/MLCK/MLC Signaling Pathway in TBI Mouse Model

Clinical studies have shown that probiotics influence gastrointestinal motility. However, the molecular mechanisms by which probiotic Lactobacillus modulates intestinal motility in traumatic brain injury (TBI) mouse model have not been explored. In the present study, we provided evidence showing that treatment of TBI mice with Lactobacillus acidophilus significantly improved the terminal ileum villus morphology, restored the impaired interstitial cells of Cajal (ICC) and the disrupted ICC networks after TBI, and prevented TBI-mediated inhibition of contractile activity in intestinal smooth muscle. Mechanistically, the decreased concentration of MLCK, phospho-MLC₂₀ and phospho-MYPT1 and increased concentration of MLCP and PKC were observed after TBI, and these events mediated by TBI were efficiently prevented by Lactobacillus acidophilus application. These findings may provide a novel mechanistic basis for the application of Lactobacillus acidophilus in the treatment of TBI.

Nutrition therapy in the optimisation of health outcomes in adult patients with moderate to severe traumatic brain injury: findings from a scoping review

INTRODUCTION

Patients who have sustained traumatic brain injury (TBI) have increased nutritional requirements yet are often unable to eat normally, and adequate nutritional therapy is needed to optimise recovery. The aim of the current scoping review was to describe the existing evidence for improved outcomes with optimal nutrition therapy in adult patients with moderate to severe TBI, and to identify gaps in the literature to inform future research.

METHODS

Using an exploratory scoping study approach, Medline, Cinahl, Embase, CENTRAL, the Neurotrauma reviews in the Global Evidence Mapping (GEM) Initiative, and Evidence Reviews in Acquired Brain Injury (ERABI) were searched from 2003 to 14 November 2013 using variations of the search terms 'traumatic brain injury' and 'nutrition'. Articles were included if they reported mortality, morbidity, or length of stay outcomes, and were classified according to the nature of nutrition intervention and study design.

RESULTS

Twenty relevant articles were identified of which: 12 were original research articles; two were systematic reviews; one a meta-analysis; and five were narrative reviews. Of these, eleven explored timing of feed provision, eight explored route of administration of feeding, nine examined the provision of specific nutrients, and none examined feeding environment. Some explored more than one intervention. Three sets of guidelines which contain feeding recommendations were also identified.

DISCUSSION

Inconsistency within nutrition intervention methods and outcome measures means that the present evidence base is inadequate for the construction of best practice guidelines for nutrition and TBI. Further research is necessary to elucidate the optimal nutrition therapy for adults with TBI with respect to the timing, route of administration, nutrient provision and feeding environment. A consensus on the ideal outcome measure and the most appropriate method and timing of its measurement is required as a foundation for this evidence base.

Alterations in enterocyte mitochondrial respiratory function and enzyme activities in gastrointestinal dysfunction following brain injury

AIM: To determine the alterations in rat enterocyte mitochondrial respiratory function and enzyme activities following traumatic brain injury (TBI).

METHODS: Fifty-six male SD rats were randomly divided into seven groups (8 rats in each group): a control group (rats with sham operation) and traumatic brain injury groups at 6, 12, 24 h, days 2, 3, and 7 after operation. TBI models were induced by Feendy’s free-falling method. Mitochondrial respiratory function (respiratory control ratio and ADP/O ratio) was measured with a Clark oxygen electrode. The activities of respiratory chain complex I-IV and related enzymes were determined by spectrophotometry.

RESULTS: Compared with the control group, the mitochondrial respiratory control ratio (RCR) declined at 6 h and remained at a low level until day 7 after TBI (control, 5.42 ± 0.46; 6 h, 5.20 ± 0.18; 12 h, 4.55 ± 0.35; 24 h, 3.75 ± 0.22; 2 d, 4.12 ± 0.53; 3 d, 3.45 ± 0.41; 7 d, 5.23 ± 0.24, P < 0.01). The value of phosphate-to-oxygen (P/O) significantly decreased at 12, 24 h, day 2 and day 3, respectively (12 h, 3.30 ± 0.10; 24 h, 2.61 ± 0.21; 2 d, 2.95 ± 0.18; 3 d, 2.76 ± 0.09, P < 0.01) compared with the control group (3.46 ± 0.12). Two troughs of mitochondrial respiratory function were seen at 24 h and day 3 after TBI. The activities of mitochondrial complex I (6 h: 110 ± 10, 12 h: 115 ± 12, 24 h: 85 ± 9, day 2: 80 ± 15, day 3: 65 ± 16, P < 0.01) and complex II (6 h: 105 ± 8, 12 h: 110 ± 92, 24 h: 80 ± 10, day 2: 76 ± 8, day 3: 68 ± 12, P < 0.01) were increased at 6 h and 12 h following TBI, and then significantly decreased at 24 h, day 2 and day 3, respectively. However, there were no differences in complex I and II activities between the control and TBI groups. Furthermore, pyruvate dehydrogenase (PDH) activity was significantly decreased at 6 h and continued up to 7 d after TBI compared with the control group (6 h: 90 ± 8, 12 h: 85 ± 10, 24 h: 65 ± 12, day 2: 60 ± 9, day 3: 55 ± 6, day 7: 88 ± 11, P < 0.01). The changes in α-ketoglutaric dehydrogenase (KGDH) activity were similar to PDH, except that the decrease in KGDH activity began at 12 h after TBI (12 h: 90 ± 12, 24 h: 80 ± 9, day 2: 76 ± 15, day 3: 68 ± 7, day 7: 90 ± 13, P < 0.01). No significant change in malate dehydrogenase (MDH) activity was observed.

CONCLUSION: Rat enterocyte mitochondrial respiratory function and enzyme activities are inhibited following TBI. Mitochondrial dysfunction may play an important role in TBI-induced gastrointestinal dysfunction.

Effects of traumatic brain injury on intestinal contractility

BACKGROUND

Patients with traumatic brain injury (TBI) often suffer from gastrointestinal dysfunction including intolerance to enteral feedings. However, it is unclear how TBI affects small intestinal contractile activity. The purpose of this study was to determine if TBI affects intestinal smooth muscle function.

METHODS

Sprague-Dawley rats were subjected to controlled cortical impact injury (TBI). Sham animals underwent a similar surgery but no injury (SHAM). Animals were sacrificed 1, 3, and 7 days after TBI and intestinal smooth muscle tissue was collected for measurement of contractile activity and transit, NF-kB activity, and cytokine levels. Brains were collected after sacrifice to determine volume loss due to injury.

KEY RESULTS

Contractile activity decreased significantly in ileum, but not jejunum, in the TBI group 7 days after injury compared with SHAM. Brain volume loss increased significantly 7 days after injury compared with 3 days and correlated significantly with the contractile activity 1 day after injury. In the intestinal smooth muscle, NF-kB activity increased significantly in the TBI group 3 and 7 days after injury vs SHAM. Wet to dry weight ratio, indicating edema, also increased significantly in the TBI group. Interleukin-1α, -1β, and -17 increased significantly in the TBI group compared with SHAM.

CONCLUSIONS & INFERENCES

Traumatic brain injury causes a delayed but significant decrease in intestinal contractile activity in the ileum leading to delayed transit. The decreased intestinal contractile activity is attributed to secondary inflammatory injury as evidenced by increased NF-kB activity, increased edema, and increased inflammatory cytokines in the intestinal smooth muscle.

Gastrointestinal dysmotility: evidence and clinical management

PURPOSE OF REVIEW

Gastrointestinal dysmotility and dysfunction underlie our difficulties in providing adequate nutrition by the enteral route to our critically ill patients.

RECENT FINDINGS

Recent studies have quantified gastric emptying and nutrient absorption. Slow gastric emptying is common and probably mediated by cholecystokinin and reduced active ghrelin concentrations. The cause of impaired nutrient absorption is not yet fully understood but may be related to small intestinal blood flow and/or mucosal factors. The absorption of the different macronutrients may be affected in different ways both by critical illness and by therapies. A better understanding of this may optimize the design of nutrient formulations in the future. New treatment modalities for gastrointestinal dysfunction are being investigated and include small intestinal feeding, nonpharmacological options such as acupuncture, and drugs including novel motilin receptor agonists, and opioid antagonists.

SUMMARY

We are gradually developing a better understanding of how the gut works during critical illness, which has implications for optimizing the delivery of nutrition and thereby improving nutritional and clinical outcomes.