584 research outputs found
Development of a Clinical Type 1 Diabetes Metabolic System Model and in Silico Simulation Tool
Invited journal symposium paperObjectives:
To develop a safe and effective protocol for the clinical control of Type 1 diabetes using conventional self-monitoring blood glucose (SMBG) measurements, and multiple daily injection (MDI) with insulin analogues. To develop an in silico simulation tool of Type 1 diabetes to predict long-term glycaemic control outcomes of clinical interventions.
Methods:
The virtual patient method is used to develop a simulation tool for Type 1 diabetes using data from a Type 1 diabetes patient cohort (n=40). The tool is used to test the adaptive protocol (AC) and a conventional intensive insulin therapy (CC) against results from a representative control cohort. Optimal and suboptimal basal insulin replacement are evaluated as a function of self-monitoring blood glucose (SMBG) frequency in conjunction with the (AC and CC) prandial control protocols.
Results:
In long-term glycaemic control, the AC protocol significantly decreases HbA1c in conditions of suboptimal basal insulin replacement for SMBG frequencies =6/day, and reduced the occurrence of mild and severe hypoglycaemia by 86-100% over controls over all SMBG frequencies in conditions of optimal basal insulin.
Conclusions:
A simulation tool to predict long-term glycaemic control outcomes from clinical interventions is developed to test a novel, adaptive control protocol for Type 1 diabetes. The protocol is effective and safe compared to conventional intensive insulin therapy and controls. As fear of hypoglycaemia is a large psychological barrier to glycaemic control, the AC protocol may represent the next evolution of intensive insulin therapy to deliver increased glycaemic control with increased safety. Further clinical or experimental validation is needed to fully prove the concept
Overview of Glycemic Control in Critical Care - Relating Performance and Clinical Results
Inagural review article invited for inaugural journalBackground: Hyperglycemia is prevalent in critical care and tight control can save
lives. Current ad-hoc clinical protocols require significant clinical effort and produce
highly variable results. Model-based methods can provide tight, patient specific
control, while addressing practical clinical difficulties and dynamic patient evolution.
However, tight control remains elusive as there is not enough understanding of the
relationship between control performance and clinical outcome.
Methods: The general problem and performance criteria are defined. The clinical
studies performed to date using both ad-hoc titration and model-based methods are
reviewed. Studies reporting mortality outcome are analysed in terms of standardized
mortality ratio (SMR) and a 95th percentile (±2 ) standard error (SE95%) to enable
better comparison across cohorts.
Results: Model-based control trials lower blood glucose into a 72-110mg/dL band
within 10 hours, have target accuracy over 90%, produce fewer hypoglycemic
episodes, and require no additional clinical intervention. Plotting SMR versus SE95%
shows potentially high correlation (r=0.84) between ICU mortality and tightness of
control.
Summary: Model-based methods provide tighter, more adaptable “one method fits
all” solutions, using methods that enable patient-specific modeling and control.
Correlation between tightness of control and clinical outcome suggests that
performance metrics, such as time in a relevant glycemic band, may provide better
guidelines. Overall, compared to current “one size fits all” sliding scale and ad-hoc
regimens, patient-specific pharmacodynamic and pharmacokinetic model-based, or
“one method fits all”, control, utilizing computational and emerging sensor
technologies, offers improved treatment and better potential outcomes when treating
hyperglycemia in the highly dynamic critically ill patient
Modeled Insulin Sensitivity and Interstitial Insulin Action from a Pilot Study of Dynamic Insulin Sensitivity Tests
An accurate test for insulin resistance can delay or prevent the development of Type 2 diabetes and its complications. The current gold standard test, CLAMP, is too labor intensive to be used in general practice. A recently developed dynamic insulin sensitivity test,
DIST, uses a glucose-insulin-C-peptide model to calculate model-based insulin sensitivity, SI.
Preliminary results show good correlation to CLAMP. However both CLAMP and DIST ignore
saturation in insulin-mediated glucose removal. This study uses the data from 17 patients who
underwent multiple DISTs to investigate interstitial insulin action and its influence on modeled
insulin sensitivity. The critical parameters influencing interstitial insulin action are saturation
in insulin receptor binding, αG, and plasma-interstitial difiusion rate, nI . Very low values of αG
and very low values of nI produced the most intra-patient variability in SI. Repeatability in SI
is enhanced with modeled insulin receptor saturation. Future parameter study on subjects with
varying degree of insulin resistance may provide a better understanding of different contributing
factors of insulin resistance
Pulmonary embolism diagnostics from the driver function
Ventricular driver functions are not readily measured in the ICU, but can clearly indicate the development of pulmonary embolism (PE) otherwise difficult to diagnose. Recent work has developed accurate methods of
measuring these driver functions from readily available ICU measurements. This research tests those methods by assessing the ability of these driver functions to diagnose the evolution of PE
Model-based diagnosis of acute pulmonary embolism and septic shock in porcine trials
peer reviewe
Model-based cardiovascular monitoring of large pore hemofiltration during endotoxic shock in pigs
peer reviewe
Implementation and evaluation of the SPRINT protocol for tight glycaemic control in critically ill patients: a clinical practice change
SPRINT was implemented as a clinical practice change in a general intensive care unit (ICU). The objective of this study was to measure the effect of the SPRINT protocol on glycaemic control and mortality compared to previous ICU control methods. Glycaemic control and mortality outcomes for 371 SPRINT patients with median acute physiology and chronic health evaluation (APACHE II) score 18 [IQR: 15-24] are compared to a 413 patient retrospective cohort with median APACHE II score of 18 [IQR: 15-23]
How Many Reindeer? UAV Surveys as an Alternative to Helicopter or Ground Surveys for Estimating Population Abundance in Open Landscapes
Conservation of wildlife depends on precise and unbiased knowledge on the abundance and distribution of species. It is challenging to choose appropriate methods to obtain a sufficiently high detectability and spatial coverage matching the species characteristics and spatiotemporal use of the landscape. In remote regions, such as in the Arctic, monitoring efforts are often resource-intensive and there is a need for cheap and precise alternative methods. Here, we compare an uncrewed aerial vehicle (UAV; quadcopter) pilot survey of the non-gregarious Svalbard reindeer to traditional
population abundance surveys from ground and helicopter to investigate whether UAVs can be an efficient alternative technology. We found that the UAV survey underestimated reindeer abundance compared to the traditional abundance surveys when used at management relevant spatial scales. Observer variation in reindeer detection on UAV imagery was influenced by the RGB greenness index and mean blue channel. In future studies, we suggest testing long-range fixed-wing UAVs to increase the sample size of reindeer and area coverage and incorporate detection probability in animal
density models from UAV imagery. In addition, we encourage focus on more efficient post-processing techniques, including automatic animal object identification with machine learning and analytical methods that account for uncertainties
High levels of untreated distress and fatigue in cancer patients
The purpose of the study was to assess a large representative sample of cancer patients on distress levels, common psychosocial problems, and awareness and use of psychosocial support services. A total of 3095 patients were assessed over a 4-week period with the Brief Symptom Inventory-18 (BSI-18), a common problems checklist, and on awareness and use of psychosocial resources. Full data was available on 2776 patients. On average, patients were 60 years old, Caucasian (78.3%), and middle class. Approximately, half were attending for follow-up care. Types of cancer varied, with the largest groups being breast (23.5%), prostate (16.9%), colorectal (7.5%), and lung (5.8%) cancer patients. Overall, 37.8% of all patients met criteria for general distress in the clinical range. A higher proportion of men met case criteria for somatisation, and more women for depression. There were no gender differences in anxiety or overall distress severity. Minority patients were more likely to be distressed, as were those with lower income, cancers other than prostate, and those currently on active treatment. Lung, pancreatic, head and neck, Hodgkin's disease, and brain cancer patients were the most distressed. Almost half of all patients who met distress criteria had not sought professional psychosocial support nor did they intend to in the future. In conclusion, distress is very common in cancer patients across diagnoses and across the disease trajectory. Many patients who report high levels of distress are not taking advantage of available supportive resources. Barriers to such use, and factors predicting distress and use of psychosocial care, require further exploration
First pilot trial of the STAR-Liege protocol for tight glycemic control in critically ill patients
peer reviewe
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