A model-based approach to generating annotated pressure support waveforms.

Large numbers of asynchronies during pressure support ventilation cause discomfort and higher work of breathing in the patient, and are associated with an increased mortality. There is a need for real-time decision support to detect asynchronies and assist the clinician towards lung-protective ventilation. Machine learning techniques have been proposed to detect asynchronies, but they require large datasets with sufficient data diversity, sample size, and quality for training purposes. In this work, we propose a method for generating a large, realistic and labeled, synthetic dataset for training and validating machine learning algorithms to detect a wide variety of asynchrony types. We take a model-based approach in which we adapt a non-linear lung-airway model for use in a diverse patient group and add a first-order ventilator model to generate labeled pressure, flow, and volume waveforms of pressure support ventilation. The model was able to reproduce basic measured lung mechanics parameters. Experienced clinicians were not able to differentiate between the simulated waveforms and clinical data (P = 0.44 by Fisher's exact test). The detection performance of the machine learning trained on clinical data gave an overall comparable true positive rate on clinical data and on simulated data (an overall true positive rate of 94.3% and positive predictive value of 93.5% on simulated data and a true positive rate of 98% and positive predictive value of 98% on clinical data). Our findings demonstrate that it is possible to generate labeled pressure and flow waveforms with different types of asynchronies.

Intelligent dynamic clinical checklists improved checklist compliance in the intensive care unit.

BACKGROUND: Checklists can reduce medical errors. However, the effectiveness of checklists is hampered by lack of acceptance and compliance. Recently, a new type of checklist with dynamic properties has been created to provide more specific checklist items for each individual patient. Our purpose in this simulation-based study was to investigate a newly developed intelligent dynamic clinical checklist (DCC) for the intensive care unit (ICU) ward round. METHODS: Eligible clinicians were invited to participate as volunteers. Highest achievable scores were established for six typical ICU scenarios to determine which items must be checked. The participants compared the DCC with the local standard of care. The primary outcomes were the caregiver satisfaction score and the percentages of checked items overall and of critical items requiring a direct intervention. RESULTS: In total, 20 participants were included, who performed 116 scenarios. The median percentage of checked items was 100.0% with the DCC and 73.6% for the scenarios completed with local standard of care ( P <0.001). Critical items remained unchecked in 23.1% of the scenarios performed with local standard of care and 0.0% of the scenarios where the DCC was available ( P <0.001). The mean satisfaction score of the DCC was 4.13 out of 5. CONCLUSIONS: This simulation study indicates that an intelligent DCC significantly increases compliance with best practice by reducing the percentage of unchecked items during ICU ward rounds, while the user satisfaction rate remains high. Real-life clinical research is required to evaluate this new type of checklist further.

Evaluation of the accuracy of established patient inspiratory effort estimation methods during mechanical support ventilation.

There is a clinical need for monitoring inspiratory effort to prevent lung- and diaphragm injury in patients who receive supportive mechanical ventilation in an Intensive Care Unit. Different pressure-based techniques are available to estimate this inspiratory effort at the bedside, but the accuracy of their effort estimation is uncertain since they are all based on a simplified linear model of the respiratory system, which omits gas compressibility of air, and the viscoelasticity and nonlinearities of the respiratory system. The aim of this in-silico study was to provide an overview of the pressure-based estimation techniques and to evaluate their accuracy using a more sophisticated model of the respiratory system and ventilator. The influence of the following parameters on the accuracy of the pressure-based estimation techniques was evaluated using the in-silico model: 1) the patient's respiratory mechanics 2) PEEP and the inspiratory pressure of the ventilator 3) gas compressibility of air 4) viscoelasticity of the respiratory system 5) the strength of the inspiratory effort. The best-performing technique in terms of accuracy was the whole breath occlusion. The average error and maximum error were the lowest for all patient archetypes. We found that the error was related to the expansion of gas in the breathing set and lungs and respiratory compliance. However, concerns exist that other factors not included in the model, such as a changed muscle-force relation during an occlusion, might influence the true accuracy. The estimation techniques based on the esophageal pressure showed an error related to the viscoelastic element in the model which leads to a higher error than the occlusion. The error of the esophageal pressure-based techniques is therefore highly dependent on the pathology of the patient and the settings of the ventilator and might change over time while a patient recovers or becomes more ill.

[The new curriculum for the University Training Course in Psychiatry in South Limburg and for the Mental Health Services in Eindhoven]. / Het vernieuwde cursorische onderwijs van de universitaire opleiding psychiatrie Zuid-Limburg en GGZ Eindhoven.

BACKGROUND: The curriculum for the Academic Training Course in Psychiatry in South- Limburg (UOP-ZL) needed to be modernised. There were widely differing views about the purpose and function of psychiatry and about the structure of the curriculum. Trainees failed to attend regularly because of their daily duties. AIM: Following discussion about the need for modernisation of the course in Psychiatry (HOOP), the UOP-ZL curriculum was thoroughly revised and updated. METHOD: Further development of HOOP, a careful study of the teaching material and discussion among members of UOP-ZL and the Mental Health Service in Eindhoven, led to the development of more unified views about psychiatry and produced the ingredients for a revised curriculum for training in psychiatry. RESULTS: In the early stages of their course, trainees are introduced to some basic principles; these include understanding the mechanisms for dimensions of affect, motivation, salience and cognition from a biological, cognitive and ecological perspective, and perceiving the relationship between these factors and normal and abnormal behaviour. The course is a mix of problem based learning and interactive classroom teaching and is delivered by clinical and scientific experts. Every two weeks the trainees in each year-group are given a whole day 'free' (i.e. free of normal duties) when they are required to attend classed and lectures. CONCLUSION: The two main results of the new curriculum are: diagnosis-related teaching has been replaced by an approach based on explanatory mechanisms for dimensional psychopathology and dysfunction, and the tuition provided is both problem-based and interactive and is given by expert teachers.

ISIS trapeziometacarpal arthroplasty: What are the outcomes in male patients?

Trapeziometacarpal arthroplasty is a well-known treatment of thumb basal joint arthritis. However, only a few studies have been done on its use specifically in men, with one of the most recent showing a high implant failure rate. Our study was a retrospective analysis of the ISIS prosthesis exclusively in men. Our hypothesis was that it is a viable therapeutic solution. Between 2010 and 2020, 23 ISIS prostheses were implanted in 19 patients. A radiological and functional analysis was done, combined with a self-evaluation by multiple validated outcome scores (visual analog scale for pain, QuickDASH, PRWE, SF36, and Kapandji scores). The median follow-up was 76 months (13-134) with a median age of 69 years. The mean pain level was 1/10, the QuickDASH was 22.7, the PRWE was 14.2, the SF-36 was 61.1 and the Kapandji score was 8.9. One dislocation occurred in one patient; two patients had to be reoperated for periprosthetic ossifications. Radiolucency was found around the cup in one patient and around the metacarpal shaft in one patient. There was no implant failure and only one case of asymptomatic loosening, with a survival rate of 94% at 111 months. In the medium-term, clinical, and functional outcomes were satisfactory with pain relief similar to that of published studies, with a low rate of complications. ISIS arthroplasty appears to be a suitable treatment for thumb basal joint arthritis in men, although a non-negligible rate of periprosthetic ossifications required revision surgery in half of the cases.

A Model-based Approach to Generating Annotated Pressure Support Waveforms.

During pressure support ventilation, every breath is triggered by the patient. Mismatches between the patient and the ventilator are called asynchronies. It has been reported that large numbers of asynchronies may be harmful and may lead to increased mortality. Automatic asynchrony detection and classification, with subsequent feedback to clinicians, will improve lung ventilation and, possibly, patient outcome. Machine learning techniques have been used to detect asynchronies. However, large, diverse and high-quality training and verification data sets are needed. In this work, we propose a model for generating a large, realistic, labeled, synthetic dataset for training and testing machine learning algorithms to detect a wide variety of asynchrony types. Next to a morphological evaluation of the obtained waveforms, validation of the proposed model includes a test with a machine learning algorithm trained on clinical data.

Effectiveness, safety and efficacy of INTELLiVENT-adaptive support ventilation, a closed-loop ventilation mode for use in ICU patients - a systematic review.

Introduction: INTELLiVENT-Adaptive Support Ventilation (INTELLiVENT-ASV), an advanced closed-loop ventilation mode for use in intensive care unit (ICU) patients, is equipped with algorithms that automatically adjust settings on the basis of physiologic signals and patient's activity. Here we describe its effectiveness, safety, and efficacy in various types of ICU patients.Areas covered: A systematic search conducted in MEDLINE, EMBASE, the Cochrane Central register of Controlled Trials (CENTRAL), and in Google Scholar identified 10 randomized clinical trials.Expert opinion: Studies suggest INTELLiVENT-ASV to be an effective automated mode with regard to the titrations of tidal volume, airway pressure, and oxygen. INTELLiVENT-ASV is as safe as conventional modes. However, thus far studies have not shown INTELLiVENT-ASV to be superior to conventional modes with regard to duration of ventilation and other patient-centered outcomes. Future studies are needed to test its efficacy.

Differences in identification of patients' deterioration may hamper the success of clinical escalation protocols.

BACKGROUND: Timely and consistent recognition of a 'clinical crisis', a life threatening condition that demands immediate intervention, is essential to reduce 'failure to rescue' rates in general wards. AIM: To determine how different clinical caregivers define a 'clinical crisis' and how they respond to it. DESIGN: An international survey. METHODS: Clinicians working on general wards, intensive care units or emergency departments in the Netherlands, the United Kingdom and Denmark were asked to review ten scenarios based on common real-life cases. Then they were asked to grade the urgency and severity of the scenario, their degree of concern, their estimate for the risk for death and indicate their preferred action for escalation. The primary outcome was the scenarios with a National Early Warning Score (NEWS) ≥7 considered to be a 'clinical crisis'. Secondary outcomes included how often a rapid response system (RRS) was activated, and if this was influenced by the participant's professional role or experience. The data from all participants in all three countries was pooled for analysis. RESULTS: A total of 150 clinicians participated in the survey. The highest percentage of clinicians that considered one of the three scenarios with a NEWS ≥7 as a 'clinical crisis' was 52%, while a RRS was activated by <50% of participants. Professional roles and job experience only had a minor influence on the recognition of a 'clinical crisis' and how it should be responded to. CONCLUSION: This international survey indicates that clinicians differ on what they consider to be a 'clinical crisis' and on how it should be managed. Even in cases with a markedly abnormal physiology (i.e. NEWS ≥7) many clinicians do not consider immediate activation of a RRS is required.

[An observational study of 'assertive outreach' with remission as outcome measure]. / Een observationele trial naar 'assertive outreach' met remissie als uitkomstmaat1.

BACKGROUND: Systems of intensive care such as the Function Assertive Community Treatment (Function-act) are advocated because they are reported to have achieved very promising results. However, comparative studies aimed at measuring the efficacy of such systems are mainly of short duration and the outcome measure is nearly always the amount of care provided. AIM: To investigate, via an observational study, changes that occurred in the number of patients going into remission and in the amount of care provided before and after the introduction of f-act. METHOD: f-act was introduced in Maastricht and the surrounding area (population 220,000) at the beginning of 2002. Cumulative routine measurements of the effect of care in the region had been performed since 1998. These measurements were used to compare the proportion of patients in remission in two non-overlapping patients cohorts, each covering a 4-year period, namely 1998-2001 and 2002-2005. results The proportion of patients who made the transition to remission increased from 19% in the period before the introduction of f-act to 31% in the period after its introduction (or = 2.21; 95% ci: 1.03-4.78), but after controlling for confounders the difference was no longer statistically significant. CONCLUSION: In routine clinical practice f-act can reduce the intensity of psychopathological symptoms, possibly because the care provided under f-act is less fragmented. However, more research is needed before the claimed beneficial effects of f-act can be proved conclusively.

An alternative ICU staffing model: implementation of the non-physician provider.

INTRODUCTION: Literature in Europe regarding implementation of nurse practitioners or physician assistants in the intensive care unit (ICU) is lacking, while some available studies indicate that this concept can improve the quality of care and overcome physician shortages on ICUs. The aim of this study is to provide insight on how a Dutch ICU implemented non-physician providers (NPP), besides residents, and what this staffing model adds to the care on the ICU. METHODS: This paper defines the training course and job description of NPPs on a Dutch ICU. It describes the number and quality of invasive interventions performed by NPPs, residents, and intensivists during the years 2015 and 2016. Salary scales of NPPs and residents are provided to describe potential cost-effectiveness. RESULTS: The tasks of NPPs on the ICU are equal to those of the residents. Analysis of the invasive interventions performed by NPPs showed an incidence of central venous catheter insertion for NPPs of 20 per fulltime equivalent (FTE) and for residents 4.3 per FTE in one year. For arterial catheters the NPP inserted 61.7 per FTE and the residents inserted 11.8 per FTE. The complication rate of both groups was in line with recent literature. Regarding their salary: after five years in service an NPP earns more than a starting resident. CONCLUSION: This is the first European study which describes the role of NPPs on the ICU and shows that practical interventions normally performed by physicians can be performed with equal safety and quality by NPPs.

Thinking beyond the mass: ANCA-associated vasculitis mimicking a pancreatic malignancy.

Isolated pancreatic involvement is a rare initial presentation in patients with ANCA-associated vasculitis. We report a patient with a suspected malignant pancreatic mass, referred to our hospital for pancreaticoduodenectomy. However, the pancreatic mass proved to be the initial manifestation of ANCA-associated vasculitis.

Influence of wheat bran on NMU-induced mammary tumor development, plasma estrogen levels and estrogen excretion in female rats.

In our animal experiments the hypothesis was tested that a high-fiber (HF) diet reduces tumor promotion by interruption of the enterohepatic circulation resulting in lowered estrogen exposure of the estrogen-sensitive tissue. In the first experiment the development of N-nitrosomethylurea (NMU) induced mammary tumors was investigated. One group of rats (HF) was fed a HF diet (11% fiber, based on wheat bran), the other group (LF) fed a low-fiber diet (0.5% fiber, based on white wheat flour). Tumor incidence (90 and 80%, respectively) and latency (121 and 128 days, respectively) were similar in the HF and LF groups. Compared to the LF group, HF rats had lower tumor weights (0.16 vs 0.55 g; P less than 0.01) and a slightly lower tumor multiplicity (1.8 vs 2.8 tumors per tumor-bearing rat). These differences were reduced after adjustment for body weight. In a second experiment rats, not treated with the carcinogen, were kept on the same HF and LF diets. From these rats 24-h urine and feces and orbital blood samples were collected for analysis of (un)conjugated estrogens. The excretion of both free and conjugated estrogens in fecal samples was about 3-fold higher in HF rats than in LF rats. During the basal period of the cycle urinary excretion of estrone was lower in HF rats (mean 9.7 ng/day) than in LF rats (mean 13.0 ng/day; P less than 0.05). It is concluded that wheat bran interrupts the enterohepatic circulation of estrogens, but plasma levels are not affected. Whether the development of mammary tumors is reduced by the introduction of specific components of wheat bran, or by a reduced body weight due to a lower (effective) energy intake remains to be determined.

Metabolism and biochemical effects of 3,3',4,4'-tetrachlorobiphenyl in pregnant and fetal rats.

The metabolism and distribution of a single oral dose of 25 mumol 14C-labelled 3,3',4,4'-tetrachlorobiphenyl (14C-TCB) were investigated in pregnant female Wistar rats and their fetuses. TCB was administered on day 13 of gestation and the elimination was followed for 7 days. Non-pregnant rats were treated similarly for comparison. Fecal elimination of 14C-TCB derived radioactivity was significantly lower in pregnant rats than in non-pregnant rats. The major metabolite found in adult liver and plasma, placental tissue, whole fetuses and fetal plasma was 3,3',4',5-tetrachloro-4-biphenylol (4-OH-TCB). Tissue levels (liver, abdominal fat, skin, skeletal muscle, kidney and plasma) of 14C-TCB-derived radioactivity declined by 65-85% over a 7-day period following administration in the adult animals. However, 14C-TCB-derived radioactivity accumulated more than 100-fold in the fetuses over the same time period, and GC/MS analysis revealed that the fetal accumulation in radioactivity was due primarily to 4-OH-TCB, and not the parent compound. On day 20 of gestation, concentrations of 4-OH-TCB were 14 times greater in fetal plasma than maternal plasma. Treatment with 14C-TCB significantly reduced plasma thyroxine levels by at least 28% up to 7 days after administration in non-pregnant animals and up to 4 days after administration in pregnant rats (31% decrease). By 7 days after administration plasma thyroxine levels had returned to control levels in the TCB-treated pregnant rats. However, fetal plasma thyroxine levels were significantly decreased by 35% in fetuses from 14C-TCB-treated dams 7 days after TCB administration. Hepatic microsomal ethoxyresorufin-O-deethylase (EROD) activity was significantly induced in TCB-treated dams relative to controls at 4 and 7 days after administration, while no EROD activity was detected in hepatic microsomes from control or TCB treated fetal rats at day 20 of gestation. These data suggest that hydroxylated metabolites of polychlorinated biphenyls may play a role in the development toxicity of these compounds.

A new radioimmunoassay for the determination of the angiotensin-converting enzyme inhibitor perindopril and its active metabolite in plasma and urine: advantages of a lysine derivative as immunogen to improve the assay specificity.

A new radioimmunoassay (RIA) was developed for the direct measurement of perindoprilate (PT), the active metabolite (diacid) of Perindopril (P), an angiotensin-converting enzyme (ACE) inhibitor. Antibodies were raised in rabbits against the lysine derivative of PT conjugated to bovine serum albumin. The p-hydroxyphenyl derivative of the lysine analogue was used for preparation of the radioligand by iodination (125I). Cross-reactivities for the glucuronide metabolites of P and PT are low (0.25 and 3.5%, respectively). The theoretical limit of detection is 0.2 nM, the sensitivity attainable with random samples is about 0.5 nM. Within- and between-assay variabilities observed were 4.2-6.7 and 2.8-5.9%, respectively (concentration range 2.1-41.7 nM). Serial dilution of plasma and urine samples showed excellent parallelism (r greater than 0.95; P less than 0.001). Recoveries of PT spiked to urine and plasma samples were 90-120%. The prodrug P can be measured in the same sample (plasma/urine) after chromatographic separation on a Dowex AG 1 x 2 anion-exchange column and quantitative alkaline hydrolysis of the P-containing fraction. It is concluded that the specificity and sensitivity of this assay are amply sufficient for pharmacokinetic studies and in patient monitoring.

Disposition of [14C]gamma-cyclodextrin in germ-free and conventional rats.

The absorption, disposition, metabolism, and excretion of 14C-labeled gamma-cyclodextrin ([14C]gamma-CD) was examined in four separate experiments with Wistar rats. In experiment 1, [14C]gamma-CD (25 microCi, 600 mg/kg body wt) was administered intravenously to four male and four female conventional rats. In experiment 2, [14C]gamma-CD (25 microCi, 1000 mg/kg body wt) was given by gavage to four male and four female germ-free rats. In experiments 3 and 4, [14C]gamma-CD (25 and 100 microCi, respectively, 1000 mg/kg body wt) was given to four male and four female conventional rats by gavage. In all experiments, 14C was measured in respiratory CO2, urine, feces, contents of the gastrointestinal tract, blood, main organs, and residual carcass. The chemical identity of the 14C-labeled compounds was examined by HPLC in urine (experiments 1-4), blood (experiments 1 and 4), and samples of intestinal contents (experiments 3 and 4). Recovered 14C was expressed as a percentage of the administered dose. Total recovery of 14C varied between about 90% (experiments 3 and 4) and 100% (experiments 1 and 2). Experiment 1 showed that about 90% of intravenously administered gamma-CD is excreted in urine within 24 h. During the first 2 h after dosing, plasma 14C levels decreased rapidly (t1/2, 15-20 min). The remaining 10% of the dose was probably excreted into the gastrointestinal tract with bile and saliva. In addition, some [14C]gamma-CD may have been degraded by plasma and tissue amylases. Since glucose is the common product of systemic hydrolysis and intestinal digestion, it is not possible to quantitate the relative flux of [14C]gamma-CD through these two pathways. Upon oral administration of [14C]gamma-CD to germ-free rats (experiment 2), about 66% of the label was expired as CO2 within 24 h. The rate of 14C exhalation reached a maximum at 90 min after dosing and then declined steadily. In the urine, and in the contents of the cecum and colon collected at 24 h, [14C]gamma-CD was not found (except for a trace in the cecum of females). In conventional rats (experiments 3 and 4), a similar, fast appearance of respiratory 14CO2 was observed. There was no delayed formation of 14CO2 due to incomplete digestion and subsequent microbial fermentation in the cecum and colon. In pooled urine collected at 4 h after dosing, a small amount of unchanged [14C]gamma-CD was detected (experiment 4). From this result, it was estimated that less than 0.02% of ingested intact gamma-CD was absorbed and excreted with the urine. It is concluded from the data that ingested [14C]gamma-CD is rapidly and essentially completely digested in the small intestine to absorbable [14C]glucose. The absorption of intact [14C]gamma-CD by passive diffusion is very low (<0.02%). Therefore, the metabolism of gamma-CD resembles closely that of starch or linear dextrins.

The healing of cranial defects by demineralized osseous implants: a radiographic, histological and radioisotope-uptake study in rats.

The purpose of this study was to evaluate by different techniques the healing effect of demineralized allogeneic bone in parietal cranial defects in rats. 45Ca incorporation was measured for nine consecutive weeks in groups of control and implanted rats. Repeated 99mTc MDP uptake measurements were performed for nine weeks on the same group of rats. Each measurement was preceded by a cranial radiography. At the end of the study the animals were sacrificed for histologic evaluation. The results of the 45Ca incorporation, 99mTc MDP uptake measurements and the histologic pictures confirmed the osteogenic capacity of demineralized allogenic bone. From the results it can concluded that 99mTc MDP uptake measurements are a powerful tool in the evaluation of the healing process. It can be utilized sequentially in the same animal and gives detailed information about the progress of osteogenic activity over the entire implant area.

Disposition of 14C-alpha-cyclodextrin in germ-free and conventional rats.

The absorption, disposition, metabolism, and excretion of uniformly (14)C-labeled alpha-cyclodextrin ((14)C-alpha-CD) was examined in four separate experiments with Wistar rats. In Experiment 1, (14)C-alpha-CD (25 microCi, 50 mg/kg bw) was administered intravenously to four male and four female conventional rats. In Experiment 2, (14)C-alpha-CD (25 microCi, 200 mg/kg bw) was given by gavage to four male and four female germ-free rats. In Experiments 3 and 4, (14)C-alpha-CD was given to groups of four male and four female conventional rats by gavage at different dose levels (100 microCi, 200 mg/kg bw; 25 microCi, 200 and 100 mg/kg bw). In all experiments, (14)C was measured in respiratory CO(2), urine, and feces over periods of 24-48 h, and in the contents of the gastrointestinal tract, blood, main organs, and residual carcass at termination of the experiments. The chemical identity of the (14)C-labeled compounds was examined by HPLC in blood (Experiment 1), urine (Experiments 1-4), feces (Experiments 2-4), and samples of intestinal contents (Experiments 2 and 4). Recovered (14)C was expressed as percentage of the administered dose. Experiment 1 showed that intravenously administered alpha-CD is excreted rapidly with urine. During the first 2h after dosing, plasma (14)C levels decreased rapidly (t(1/2), 26 and 21 min in male and female rats, respectively). About 13% of the administered (14)C dose (range 4.6-30.6) was detected in the feces, respiratory CO(2), organs, and carcass at the end of the experiment, i.e., 24 h after dosing. The presence of about 1.9% in the intestinal contents and feces suggests that a certain fraction of systemic alpha-CD is eliminated with the bile or saliva. Conclusive evidence, either positive or negative, for a hydrolysis and further metabolism of a small fraction of the administered alpha-CD by the enzymes of the mammalian body could not be gained from this experiment. Upon oral administration of (14)C-alpha-CD to germ-free rats (Experiment 2), about 1.3% of the label expired as CO(2) within 24 h. In the urine collected from 0 to 8 h after dosing, (14)C-alpha-CD was the only radiolabeled compound detected. The amounts of alpha-CD detected in the urine suggest that on average about 1% of an oral dose is absorbed in rats during small-intestinal passage. In conventional rats (Experiments 3 and 4), a delayed appearance of respiratory (14)CO(2) was observed which is attributed to the non-digestibility of alpha-CD and its subsequent microbial fermentation in the cecum and colon. In the urine collected at 4 h after dosing, a small amount of unchanged (14)C-alpha-CD was detected which confirms that about 1% of the ingested alpha-CD is absorbed intact and is excreted via the kidneys. No (14)C-alpha-CD was found in the feces. It is concluded from the data that ingested (14)C-alpha-CD is not digested in the small intestine of rats but is fermented completely by the intestinal microbiota to absorbable short-chain fatty acids. Therefore, the metabolism of alpha-CD resembles closely that of resistant starch or other fermentable dietary fibers.