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1.
Comput Biol Med ; 142: 105191, 2022 03.
Article in English | MEDLINE | ID: mdl-35026571

ABSTRACT

Automatic cardiac chamber and left ventricular (LV) myocardium segmentation over the cardiac cycle significantly extends the utilization of contrast-enhanced cardiac CT, potentially enabling in-depth assessment of cardiac function. Therefore, we evaluate an automatic method for cardiac chamber and LV myocardium segmentation in 4D cardiac CT. In this study, 4D contrast-enhanced cardiac CT scans of 1509 patients selected for transcatheter aortic valve implantation with 21,605 3D images, were divided into development (N = 12) and test set (N = 1497). 3D convolutional neural networks were trained with end-systolic (ES) and end-diastolic (ED) images. Dice similarity coefficient (DSC) and average symmetric surface distance (ASSD) were computed for 3D segmentations at ES and ED in the development set via cross-validation, and for 2D segmentations in four cardiac phases for 81 test set patients. Segmentation quality in the full test set of 1497 patients was assessed visually on a three-point scale per structure based on estimated overlap with the ground truth. Automatic segmentation resulted in a mean DSC of 0.89 ± 0.10 and ASSD of 1.43 ± 1.45 mm in 12 patients in 3D, and a DSC of 0.89 ± 0.08 and ASSD of 1.86 ± 1.20 mm in 81 patients in 2D. The qualitative evaluation in the whole test set of 1497 patients showed that automatic segmentations were assigned grade 1 (clinically useful) in 98.5%, 92.2%, 83.1%, 96.3%, and 91.6% of cases for LV cavity and myocardium, right ventricle, left atrium, and right atrium. Our automatic method using convolutional neural networks performed clinically useful segmentation across the cardiac cycle in a large set of 4D cardiac CT images, potentially enabling in-depth assessment of cardiac function.


Subject(s)
Deep Learning , Four-Dimensional Computed Tomography , Heart/diagnostic imaging , Humans , Image Processing, Computer-Assisted/methods , Neural Networks, Computer
2.
Eur Radiol ; 32(1): 143-151, 2022 Jan.
Article in English | MEDLINE | ID: mdl-34132873

ABSTRACT

OBJECTIVES: Computed tomography angiography (CTA) is performed routinely in the work-up for transcatheter aortic valve implantation (TAVI), and could potentially replace invasive coronary angiography (ICA) to rule out left main (LM) and proximal coronary stenosis. The objectives were to assess the diagnostic yield and accuracy of pre-TAVI CTA to detect LM and proximal coronary stenosis of ≥ 50% and ≥ 70% diameter stenosis (DS). METHODS: The DEPICT CTA database consists of individual patient data from four studies with a retrospective design that analyzed the diagnostic accuracy of pre-TAVI CTA to detect coronary stenosis, as compared with ICA. Pooled data were used to assess diagnostic accuracy to detect coronary stenosis in the left main and the three proximal coronary segments on a per-patient and a per-segment level. We included 1060 patients (mean age: 81.5 years, 42.7% male). RESULTS: On ICA, the prevalence of proximal stenosis was 29.0% (≥ 50% DS) and 15.7% (≥ 70% DS). Pre-TAVI CTA ruled out ≥ 50% DS in 51.6% of patients with a sensitivity of 96.4%, specificity of 71.2%, PPV of 57.7%, and NPV of 98.0%. For ≥ 70% DS, pre-TAVI CTA ruled out stenosis in 70.0% of patients with a sensitivity of 96.7%, specificity of 87.5%, PPV of 66.9%, and NPV of 99.0%. CONCLUSION: CTA provides high diagnostic accuracy to rule out LM and proximal coronary stenosis in patients undergoing work-up for TAVI. Clinical application of CTA as a gatekeeper for ICA would reduce the need for ICA in 52% or 70% of patients, using a threshold of ≥ 50% or ≥ 70% DS, respectively. KEY POINTS: • Clinical application of CTA as a gatekeeper for ICA would reduce the need for ICA in 52% or 70% of TAVI patients, using a threshold of ≥ 50% or ≥ 70% diameter stenosis. • The diagnostic accuracy of CTA to exclude proximal coronary stenosis in these patients is high, with a sensitivity of 96.4% and NPV of 98.0% for a threshold of ≥ 50%, and a sensitivity of 96.7% and NPV of 99.0% for a threshold of ≥ 70% diameter stenosis. • Atrial fibrillation and heart rate did not significantly affect sensitivity and NPV. However, a heart rate of < 70 b/min during CTA was associated with a significantly improved specificity and PPV.


Subject(s)
Aortic Valve Stenosis , Coronary Stenosis , Transcatheter Aortic Valve Replacement , Aged, 80 and over , Aortic Valve , Aortic Valve Stenosis/diagnostic imaging , Aortic Valve Stenosis/surgery , Computed Tomography Angiography , Coronary Angiography , Coronary Stenosis/diagnostic imaging , Female , Humans , Male , Retrospective Studies
3.
J Invasive Cardiol ; 33(10): E823-E832, 2021 Oct.
Article in English | MEDLINE | ID: mdl-34609327

ABSTRACT

OBJECTIVES: To analyze the effect of percutaneous coronary intervention (PCI) before transcatheter aortic valve replacement (TAVR) on all-cause and cardiovascular mortality after TAVR, differentiating between significant proximal lesions and the non-proximal (residual) lesions. METHODS: An institutional TAVR database was complemented with data on the extent of coronary artery disease (CAD), lesion location, lesion severity, and the location of PCI. Survival analysis was performed to investigate the impact on 6-month and 3-year mortality after TAVR in all patients and in subgroups of patients with significant proximal lesions (>70% diameter stenosis [DS], >50% DS in left main), the non-proximal residual lesions, and in a propensity score matched cohort. RESULTS: Among the 577 included patients, mean age was 83 years, 50% were female, and 31% had diabetes mellitus. Preprocedural PCI of unselected lesions was independently associated with increased 6-month mortality (hazard ratio, 2.2; 95% confidence interval, 1.0-4.6; P=.04), but selective PCI of significant proximal lesions did not have an association with higher mortality, nor did we find a significant effect of PCI on mortality in the propensity-matched cohort. CONCLUSION: Routine pre-TAVR PCI is not associated with mortality reduction in TAVR patients with coronary lesions in any segment or in patients with proximal coronary lesions. Despite the lack of a beneficial effect of routine pre-TAVR PCI, we cannot exclude a beneficial effect in a selection of patients with proximal lesions. Therefore, we strongly support the current clinical guidelines to only consider pre-TAVR PCI in proximal coronary lesions, while advocating a restrictive pre-TAVR PCI strategy.


Subject(s)
Aortic Valve Stenosis , Coronary Artery Disease , Percutaneous Coronary Intervention , Transcatheter Aortic Valve Replacement , Aged, 80 and over , Aortic Valve/diagnostic imaging , Aortic Valve/surgery , Aortic Valve Stenosis/diagnosis , Aortic Valve Stenosis/surgery , Coronary Artery Disease/diagnosis , Coronary Artery Disease/surgery , Female , Humans , Percutaneous Coronary Intervention/adverse effects , Risk Factors , Transcatheter Aortic Valve Replacement/adverse effects , Treatment Outcome
4.
J Thorac Imaging ; 36(6): 353-359, 2021 Nov 01.
Article in English | MEDLINE | ID: mdl-34269752

ABSTRACT

PURPOSE: The first objective of this study was to evaluate the efficacy of a patient-tailored contrast delivery protocol for coronary computed tomography angiography (CTCA), in terms of diagnostic coronary attenuation and total iodine load (TIL), by adjusting the iodine delivery rate (IDR) via dilution for body weight and tube voltage (kV), as compared with a protocol with a fixed bolus of contrast in a clinical setting. The secondary objective was to assess the association between the test-bolus data and luminal attenuation in CTCA. MATERIALS AND METHODS: Patients who underwent CTCA with fixed IDR contrast delivery (cohort 1) or with IDR adjusted for body weight and kV settings (70 to 120 kV) (cohort 2) were included, and compared for intravascular luminal attenuation and TIL. The association between intravascular luminal attenuation and test-bolus scan data was investigated with linear regression. RESULTS: In cohort 1 (176 patients), the mean luminal attenuation differed markedly between kV categories, whereas in cohort 2 (154 patients), there were no marked differences. The mean TIL reduced significantly (20.1±1.2 g in cohort 1, 17.7±3.0 g in cohort 2, P<0.001). The peak height of the test-bolus scan was independently associated with luminal attenuation in the ascending aorta, with a 0.58 HU increase per HU peak-height increase (SE=0.18, P<0.001). CONCLUSION: Clinical implementation of a patient-tailored contrast delivery protocol for CTCA, adjusted for body weight and kV, improves luminal attenuation and significantly reduces the TIL. The peak height of the test-bolus scan is associated with luminal attenuation in the ascending aorta in the CTCA scan.


Subject(s)
Computed Tomography Angiography , Iodine , Contrast Media , Coronary Angiography , Humans , Tomography, X-Ray Computed
5.
J Clin Med ; 10(11)2021 May 28.
Article in English | MEDLINE | ID: mdl-34071249

ABSTRACT

To assess the need for additional invasive coronary angiography (CAG) after initial computed tomography coronary angiography (CTCA) in patients awaiting non-coronary cardiac surgery and in patients with cardiomyopathy, heart failure or ventricular arrhythmias, and to determine differences between patients that were referred to initial CTCA or direct CAG, consecutive patients were included between August 2017 and January 2020 and categorized as those referred to initial CTCA (conform protocol), and to direct CAG (non-conform protocol). Out of a total of 415 patients, 78.8% (327 patients, mean age: 57.9 years, 67.3% male) were referred to initial CTCA, of whom 260 patients (79.5%) had no obstructive lesions (<50% DS). A total of 55 patients (16.8%) underwent additional CAG after initial CTCA, which showed coronary lesions of >50% DS in 21 patients (6.3% of 327). Eighty-eight patients (mean age: 66.0 years, 59.1% male) were directly referred to CAG (non-conform protocol). These patients were older and had more cardiovascular risk factors compared to patients that underwent initial CTCA (conform protocol), and coronary lesions of >50% DS were detected in 16 patients (17.2%). Revascularization procedures were infrequently performed in both groups: initial CTCA (3.0%), direct CAG (3.4%). The use of CTCA as a gatekeeper CAG in the diagnostic work-up of non-coronary cardiac surgery, cardiomyopathy, heart failure and ventricular arrhythmias is feasible, and only 17% of these patients required additional CAG after initial CTCA. Therefore, CTCA should be considered as the initial imaging modality to rule out CAD in these patients.

6.
Mycorrhiza ; 31(4): 511-517, 2021 Jul.
Article in English | MEDLINE | ID: mdl-33982140

ABSTRACT

Very little is known about the impact of flooding and ground saturation on ectomycorrhizal fungi (EcM) and increasing flood events are expected with predicted climate change. To explore this, seedlings inoculated with the EcM species Tuber aestivum were exposed to a range of flood durations. Oak seedlings inoculated with T. aestivum were submerged for between 7 and 65 days. After a minimum of 114-day recovery, seedling growth measurements were recorded, and root systems were destructively sampled to measure the number of existing mycorrhizae in different zones. Number of mycorrhizae did not display correlation with seedling growth measurements. Seven days of submersion resulted in a significant reduction in mycorrhizae numbers and numbers reduced most drastically in the upper zones. Increases in duration of submersion further impacted mycorrhizae numbers in the lowest soil zone only. T. aestivum mycorrhizae can survive flood durations of at least 65 days. After flooding, mycorrhizae occur in higher numbers in the lowest soil zone, suggesting a mix of resilience and recovery. The results will aid in furthering our understanding of EcM but also may aid in conservation initiatives as well as providing insight for those whose livelihoods revolve around the collection of EcM fruiting bodies or cropping of the plant partners.


Subject(s)
Ascomycota , Mycorrhizae , Quercus , Floods
7.
Circ Cardiovasc Interv ; 12(8): e007322, 2019 08.
Article in English | MEDLINE | ID: mdl-31518164

ABSTRACT

BACKGROUND: In patients with stable coronary artery disease, the amount of myocardium subtended by coronary stenoses constitutes a major determinant of prognosis, as well as of the benefit of coronary revascularization. We devised a novel method to estimate partial myocardial mass (PMM; ie, the amount of myocardium subtended by a stenosis) during physiological stenosis interrogation. Subsequently, we validated the index against equivalent PMM values derived from applying the Voronoi algorithm on coronary computed tomography angiography. METHODS: Based on the myocardial metabolic demand and blood supply, PMM was calculated as follows: PMM (g)=APV×D2×π/(1.24×10-3×HR×sBP+1.6), where APV indicates average peak blood flow velocity; D, vessel diameter; HR, heart rate; and sBP, systolic blood pressure. We calculated PMM to 43 coronary vessels (32 patients) interrogated with pressure and Doppler guidewires, and compared it with computed tomography-based PMM. RESULTS: Median PMM was 15.8 g (Q1, Q3: 11.7, 28.4 g) for physiology-based PMM, and 17.0 g (Q1, Q3: 12.5, 25.9 g) for computed tomography-based PMM (P=0.84). Spearman rank correlation coefficient was 0.916 (P<0.001), and Passing-Bablok analysis revealed absence of both constant and proportional differences (coefficient A: -0.9; 95% CI, -4.5 to 0.9; and coefficient B, 1.00; 95% CI, 0.91 to 1.25]. Bland-Altman analysis documented a mean bias of 0.5 g (limit of agreement: -9.1 to 10.2 g). CONCLUSIONS: Physiology-based calculation of PMM in the catheterization laboratory is feasible and can be accurately performed as part of functional stenosis assessment.


Subject(s)
Coronary Artery Disease/diagnosis , Coronary Circulation , Coronary Stenosis/diagnosis , Coronary Vessels/physiopathology , Energy Metabolism , Models, Biological , Myocardium/metabolism , Aged , Blood Flow Velocity , Cardiac Catheterization , Computed Tomography Angiography , Coronary Angiography , Coronary Artery Disease/metabolism , Coronary Artery Disease/physiopathology , Coronary Stenosis/metabolism , Coronary Stenosis/physiopathology , Coronary Vessels/diagnostic imaging , Feasibility Studies , Female , Humans , Japan , Male , Middle Aged , Netherlands , Oxygen Consumption , Predictive Value of Tests , Reproducibility of Results
8.
Tech Coloproctol ; 23(8): 761-767, 2019 Aug.
Article in English | MEDLINE | ID: mdl-31392530

ABSTRACT

BACKGROUND: Current evidence suggests that pelvic floor reconstruction following extralevator abdominoperineal excision of rectum (ELAPER) may reduce the risk of perineal herniation of intra-abdominal contents. Options for reconstruction include mesh and myocutaneous flaps, for which long-term follow-up data is lacking. The aim of this study was to evaluate the long-term outcomes of biological mesh (Surgisis®, Biodesign™) reconstruction following ELAPER. METHODS: A retrospective review of all patients having ELAPER in a single institution between 2008 and 2018 was perfomed. Clinic letters were scrutinised for wound complications and all available cross sectional imaging was reviewed to identify evidence of perineal herniation (defined as presence of intra-abdominal content below a line between the coccyx and the lower margin of the pubic symphysis on sagittal view). RESULTS: One hundred patients were identified (median age 66, IQR 59-72 years, 70% male). Median length of follow-up was 4.9 years (IQR 2.3-6.7 years). One, 2- and 5-year mortality rates were 3, 8 and 12%, respectively. Thirty three perineal wounds had not healed by 1 month, but no mesh was infected and no mesh needed to be removed. Only one patient developed a symptomatic perineal hernia requiring repair. On review of imaging a further 7 asymptomatic perineal hernias were detected. At 4 years the cumulative radiologically detected perineal hernia rate was 8%. CONCLUSIONS: This study demonstrates that pelvic floor reconstruction using biological mesh following ELAPER is both safe and effective as a long-term solution, with low major complication rates. Symptomatic perineal herniation is rare following mesh reconstruction, but may develop sub clinically and be detectable on cross-sectional imaging.


Subject(s)
Hernia, Abdominal/prevention & control , Incisional Hernia/prevention & control , Pelvic Floor/surgery , Plastic Surgery Procedures/methods , Proctectomy/adverse effects , Surgical Mesh , Aged , Female , Hernia, Abdominal/etiology , Humans , Incisional Hernia/etiology , Male , Middle Aged , Perineum/surgery , Rectum/surgery , Retrospective Studies , Treatment Outcome
9.
Int J Cardiovasc Imaging ; 35(11): 2123-2133, 2019 Nov.
Article in English | MEDLINE | ID: mdl-31312998

ABSTRACT

Chronic silent brain infarctions, detected as new white matter hyperintensities on magnetic resonance imaging (MRI) following transcatheter aortic valve implantation (TAVI), are associated with long-term cognitive deterioration. This is the first study to investigate to which extent the calcification volume of the native aortic valve (AV) measured with cardiac computed tomography angiography (CTA) predicts the increase in chronic white matter hyperintensity volume after TAVI. A total of 36 patients (79 ± 5 years, median EuroSCORE II 1.9%, Q1-Q3 1.5-3.4%) with severe AV stenosis underwent fluid attenuation inversion recovery (FLAIR) MRI < 24 h prior to TAVI and at 3 months follow-up for assessment of cerebral white matter hyperintensity volume (mL). Calcification volumes (mm3) of the AV, aortic arch, landing zone and left ventricle were measured on the CTA pre-TAVI. The largest calcification volumes were found in the AV (median 692 mm3) and aortic arch (median 633 mm3), with a large variation between patients (Q1-Q3 482-1297 mm3 and 213-1727 mm3, respectively). The white matter hyperintensity volume increased in 72% of the patients. In these patients the median volume increase was of 1.1 mL (Q1-Q3 0.3-4.6 mL), corresponding with a 27% increase from baseline (Q1-Q3 7-104%). The calcification volume in the AV predicted the increase of white matter hyperintensity volume (Δ%), with a 35% increase of white matter hyperintensity volume, per 100 mm3 of AV calcification volume (SE 8.5, p < 0.001). The calcification volumes in the aortic arch, landing zone and left ventricle were not associated with the increase in white matter hyperintensity volume. In 72% of the patients new chronic white matter hyperintensities developed 3 months after TAVI, with a median increase of 27%. A higher calcification volume in the AV was associated with a larger increase in the white matter hyperintensity volume. These findings show the potential for automated AV calcium screening as an imaging biomarker to predict chronic silent brain infarctions.


Subject(s)
Aortic Valve Stenosis/surgery , Cerebral Infarction/etiology , Leukoencephalopathies/etiology , Transcatheter Aortic Valve Replacement/adverse effects , Aged , Aged, 80 and over , Aortic Valve Stenosis/complications , Aortic Valve Stenosis/diagnostic imaging , Asymptomatic Diseases , Cerebral Infarction/diagnostic imaging , Chronic Disease , Computed Tomography Angiography , Coronary Angiography/methods , Female , Humans , Leukoencephalopathies/diagnostic imaging , Magnetic Resonance Imaging , Male , Prospective Studies , Risk Assessment , Risk Factors , Time Factors , Treatment Outcome
10.
JACC Case Rep ; 1(2): 101-104, 2019 Aug.
Article in English | MEDLINE | ID: mdl-34316759

ABSTRACT

This case report underlines the complexity of the transcatheter aortic valve replacement (TAVR) procedure where rare complications sometimes are inevitable, even in experienced hands. Supra-annular dislocation of the balloon-expandable prosthesis was caused by loss of capture of the temporary transvenous pacemaker lead and treated successfully by retracting it towards the abdominal aorta. (Level of Difficulty: Advanced.).

11.
Catheter Cardiovasc Interv ; 91(2): 267-270, 2018 02 01.
Article in English | MEDLINE | ID: mdl-28699262

ABSTRACT

We present a case of a 47-year-old woman with a mechanical mitral valve prosthesis and recurrent myocardial infarction. The most common etiology of spontaneous myocardial infarction is an acute coronary syndrome caused by rupture or erosion of an atherosclerotic plaque. However, the differential diagnosis in the patient described below also included infarction due to embolization or coronary spasm. It can be challenging to discriminate between the different causes of myocardial infarction based on interpretation of symptoms, physical examination, laboratory tests, and electrocardiography alone. This report illustrates the value of coronary angiography with invasive coronary spasm provocation testing using intracoronary acetylcholine to identify the etiology of her recurrent myocardial infarctions.


Subject(s)
Coronary Vasospasm/complications , Heart Valve Prosthesis Implantation/instrumentation , Heart Valve Prosthesis , Mitral Valve/surgery , Myocardial Infarction/etiology , Acetylcholine/administration & dosage , Coronary Angiography , Coronary Vasospasm/diagnostic imaging , Coronary Vasospasm/drug therapy , Electrocardiography , Female , Humans , Middle Aged , Mitral Valve/physiopathology , Myocardial Infarction/diagnosis , Myocardial Infarction/drug therapy , Predictive Value of Tests , Recurrence
12.
BMJ Open ; 7(2): e012766, 2017 02 10.
Article in English | MEDLINE | ID: mdl-28188151

ABSTRACT

OBJECTIVE: To establish the feasibility of conducting a definitive randomised controlled trial (RCT) comparing the effectiveness of resuturing versus expectant management for dehisced perineal wounds. DESIGN: A multicentre pilot and feasibility RCT. SETTING: Ten UK maternity units from July 2011 to July 2013. POPULATION: Eligible women with a dehisced perineal wound within 2 weeks of childbirth. METHODS: The interventions were resuturing or expectancy. Randomisation was via web or telephone, stratified by participating centre. Blinding was not possible due to the nature of the interventions. Analysis was by intention-to-treat. OUTCOME: The primary outcome measure was wound healing at 6-8 weeks. RESULTS: The study revealed a number of feasibility issues, particularly strong patient and clinician preference for treatment options at recruiting centres and the timing of the primary outcome measure. Thirty-four women were randomised (17 in each arm). Data from 33 women were analysed on an intention-to-treat analysis to obtain preliminary estimates of effect size. There was a difference in wound healing at 2 weeks favouring resuturing (OR 20.00, 95% CI 2.04 to 196.37, p=0.004). However, by 6-8 weeks all but one wound in both groups had healed. CONCLUSIONS: PREVIEW revealed a number of feasibility issues, which impacted on recruitment rate. These will have to be taken into account in the design of any future definitive study. In this feasibility study, resuturing was associated with quicker wound healing and women reported higher satisfaction rates with the outcome at 3 months. TRIAL REGISTRATION NUMBER: ISRCTN05754020.


Subject(s)
Conservative Treatment , Delivery, Obstetric , Lacerations/surgery , Perineum/injuries , Surgical Wound Dehiscence/therapy , Suture Techniques , Adult , Feasibility Studies , Female , Humans , Patient Satisfaction , Perineum/surgery , Pilot Projects , Pregnancy , Treatment Outcome , United Kingdom , Wound Healing , Young Adult
13.
Biotechnol Bioeng ; 113(9): 1962-74, 2016 09.
Article in English | MEDLINE | ID: mdl-26887287

ABSTRACT

For engineers, it is interesting to gain insight in the effect of control strategies on microbial communities, on their turn influencing the process behavior and its stability. This contribution assesses the influence of process dynamics on the microbial community in a biofilm reactor for nitrogen removal, which was controlled according to several strategies aiming at nitrite accumulation. The process dataset, combining conventional chemical and physical data with molecular information, was analyzed through a correlation analysis and in a simulation study. During nitrate formation, an increased nitrogen loading rate (NLR) resulted in a drop of the bulk liquid oxygen concentration without resulting in nitrite accumulation. A biofilm model was able to reproduce the bulk liquid nitrogen concentrations in two periods before and after this increased NLR. As the microbial parameters calibrated for the ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB) in both periods were different, it was concluded that the increased NLR governed an AOB and NOB population shift. Based on the molecular data, it was assumed that each period was typified by one dominant AOB and probably several subdominant NOB populations. The control strategies for nitrite accumulation influenced the bulk liquid composition by controlling the competition between AOB and NOB. Biotechnol. Bioeng. 2016;113: 1962-1974. © 2016 Wiley Periodicals, Inc.


Subject(s)
Bacteria/metabolism , Biofilms , Bioreactors/microbiology , Models, Biological , Nitrogen/metabolism , Bacteria/chemistry , Computer Simulation , Nitrification
14.
Water Sci Technol ; 72(10): 1692-9, 2015.
Article in English | MEDLINE | ID: mdl-26540529

ABSTRACT

A model describing a given system should be as simple as possible - but not simpler. The appropriate level of complexity depends both on the type of system and on the intended use of the model. This paper addresses the critical question of which purposes justify increased complexity of biofilm (reactor) models. Additional model features compared to conventional models considered are: (1) the inclusion of microbial diversity, distinguishing between different species performing the same function; and (2) the distinction between flocs and granules in putatively granular sludge reactors. With a multispecies model considering interspecies diversity, it was demonstrated that a given macroscopic reactor performance does not necessarily reflect steady state conditions on the microscale. In a second case study, it was shown that the addition of a small level of flocs can have a significant impact on macroscale process performance and on microbial population and activity distributions in granular sludge reactors. It was concluded that increased complexity in biofilm models, concerning microbial diversity or mesoscale aggregate architecture, is likely more useful when the focus is on understanding fundamental microscale outputs, but under specific conditions, these additional model features can be critically informative for bulk reactor behavior prediction and general understanding.


Subject(s)
Bioreactors/microbiology , Models, Theoretical , Biodiversity , Biofilms , Microbial Consortia , Sewage
15.
BMJ Open ; 5(10): e008274, 2015 Oct 20.
Article in English | MEDLINE | ID: mdl-26486976

ABSTRACT

OBJECTIVES: To explore cross-sectional patterns of use of fatigue management strategies in people with multiple sclerosis (MS) who had attended a group-based fatigue management programme, Fatigue: Applying Cognitive behavioural and Energy effectiveness Techniques to lifeStyle ('FACETS'). In a multicentre randomised controlled trial (RCT) the FACETS programme was shown to reduce fatigue severity and improve self-efficacy and quality of life. DESIGN: A questionnaire substudy within a RCT involving the self-completed Fatigue Management Strategies Questionnaire (FMSQ). The FMSQ includes: (1) closed questions about the use and helpfulness of fatigue management strategies taught in FACETS and (2) open items about changes to lifestyle, attitudes or expectations, barriers or difficulties encountered and helpful strategies not covered in FACETS. PARTICIPANTS: All had a clinical diagnosis of MS, significant fatigue, were ambulatory and had attended at least 4 of 6 scheduled FACETS sessions. METHODS: Participants (n=72) were posted the FMSQ with a prepaid return envelope 4 months after the end of the FACETS programme. RESULTS: 82% (59/72) of participants returned the FMSQ. The fatigue management strategies most frequently used since attending FACETS were prioritisation (80%), pacing (78%), saying no to others (78%), grading tasks (75%) and challenging unhelpful thoughts (71%). Adding in those participants who were already using the respective strategies prior to FACETS, the three most used strategies at 4 months were prioritisation (55/59), grading (54/59) and pacing (53/58). Free-text comments illustrated the complex interplay between attitudes/expectations, behaviours, emotions and the environment. Issues related to expectations featured strongly in participants' comments. Expectations (from self and others) were both facilitators and barriers to effective fatigue management. CONCLUSIONS: Individuals' comments highlighted the complex, multifaceted nature of fatigue management. Revising expectations and a greater acceptance of fatigue were important shifts following the programme. Findings support the relevance of a cognitive behavioural approach for fatigue management. Booster sessions might be a useful addition to the FACETS programme. TRIAL REGISTRATION NUMBER: Current controlled trials ISRCTN76517470; Results.


Subject(s)
Cognitive Behavioral Therapy/methods , Fatigue/therapy , Multiple Sclerosis/psychology , Surveys and Questionnaires , Adult , Aged , Cross-Sectional Studies , Female , Humans , Life Style , Male , Middle Aged , Program Evaluation , Qualitative Research , Quality of Life , Self Efficacy , United Kingdom , Young Adult
17.
Anaesthesia ; 69(7): 687-92, 2014 Jul.
Article in English | MEDLINE | ID: mdl-24801160

ABSTRACT

The Confidential Enquiries into Maternal Deaths in the UK have recommended obstetric early warning systems for early identification of clinical deterioration to reduce maternal morbidity and mortality. This survey explored early warning systems currently used by maternity units in the UK. An electronic questionnaire was sent to all 205 lead obstetric anaesthetists under the auspices of the Obstetric Anaesthetists' Association, generating 130 (63%) responses. All respondents reported use of an obstetric early warning system, compared with 19% in a similar survey in 2007. Respondents agreed that the six most important physiological parameters to record were respiratory rate, heart rate, temperature, systolic and diastolic blood pressure and oxygen saturation. One hundred and eighteen (91%) lead anaesthetists agreed that early warning systems helped to prevent obstetric morbidity. Staffing pressures were perceived as the greatest barrier to their use, and improved audit, education and training for healthcare professionals were identified as priority areas.


Subject(s)
Anesthesia, Obstetrical/standards , Health Care Surveys/methods , Pregnancy Complications/diagnosis , Safety Management/methods , Vital Signs/physiology , Blood Pressure , Body Temperature , Early Diagnosis , Female , Guidelines as Topic , Health Care Surveys/statistics & numerical data , Heart Rate , Humans , Oxygen/blood , Pregnancy , Respiratory Rate , Surveys and Questionnaires , United Kingdom
18.
BJOG ; 121(4): 447-56, 2014 Mar.
Article in English | MEDLINE | ID: mdl-24289216

ABSTRACT

OBJECTIVE: Intramuscular (i.m.) pethidine is used worldwide for labour analgesia and i.m. diamorphine usage has increased in the UK in the last 15 years. This trial aims to ascertain the relative efficacy and adverse effects of diamorphine and pethidine for labour pain. DESIGN: Prospective, parallel-arm randomised controlled trial with blinding of participants, care-givers and outcome assessors. SETTING: Maternity units in two District General Hospitals in the UK. POPULATION: After written informed consent, 484 women were randomised and recruited (244 diamorphine, 240 pethidine). Inclusion criteria included women 16 years or older, established labour, singleton pregnancy, 37-42 weeks of gestation and weight 60-120 kg. METHODS: On request of i.m. analgesia, participants received either 150 mg pethidine or 7.5 mg diamorphine based on computer-generated block randomisation. MAIN OUTCOME MEASURES: Maternal-reduction in pain intensity from baseline (10-cm visual analogue scale) at 60 minutes and over the 3-hour period after drug administration. Neonatal-requirement for resuscitation and Apgar score at 1 minute. RESULTS: Diamorphine provided modestly improved pain relief at 60 minutes, mean difference 1 cm (95% confidence interval [CI] 0.5-1.5), and over the 3 hours, mean difference 0.7 cm (95% CI 0.3-1.1). However, average length of labour in women receiving diamorphine was 82 minutes longer (95% CI 39-124) and therefore they experienced more pain overall. There were no statistically significant differences in primary neonatal outcomes. CONCLUSIONS: There is a modest difference between the analgesia provided by diamorphine or pethidine for labour analgesia but diamorphine is associated with significantly longer labours.


Subject(s)
Analgesia, Obstetrical/methods , Analgesics, Opioid/therapeutic use , Heroin/therapeutic use , Labor Pain/drug therapy , Meperidine/therapeutic use , Adolescent , Adult , Double-Blind Method , Drug Administration Schedule , Female , Humans , Injections, Intramuscular , Logistic Models , Pain Measurement , Pregnancy , Prospective Studies , Treatment Outcome , Young Adult
19.
Anaesthesia ; 68(9): 899-903, 2013 Sep.
Article in English | MEDLINE | ID: mdl-23789738

ABSTRACT

We undertook a randomised, controlled trial to compare the analgesic efficacy and opioid sparing effect of nerve stimulator-guided femoral nerve block with fascia iliaca compartment block in patients awaiting surgery for fractured neck of femur. Ten-centimetre visual analogue pain scores were measured before and 2 h after the block and opioid consumption was recorded in the 12-h period after the block. One hundred and ten patients were randomly assigned. Femoral nerve block provided superior pre-operative analgesia for fractured neck of femur compared with fascia iliaca compartment block. The difference in the mean reduction of pain score after the block was 0.9 (95% CI 0-1.8); p = 0.047. Patients receiving a femoral nerve block required less morphine after the block than those receiving fascia iliaca compartment block (p = 0.041).


Subject(s)
Femoral Neck Fractures/surgery , Nerve Block/methods , Pain/drug therapy , Preoperative Care/methods , Aged , Aged, 80 and over , Analgesics, Opioid/administration & dosage , Anesthetics, Local , Bupivacaine/analogs & derivatives , Electric Stimulation/methods , Fascia , Female , Femoral Nerve , Humans , Levobupivacaine , Male , Middle Aged , Pain Management/methods , Pain Measurement/methods
20.
Diabet Med ; 29(5): 662-9, 2012 May.
Article in English | MEDLINE | ID: mdl-21978203

ABSTRACT

AIMS: To assess the numeracy and literacy skills of individuals with Type 1 diabetes and determine if there is a relationship with achieved glycaemic control independent of their duration of diabetes, diabetes education, demographic and socio-economic factors. METHODS: One hundred and twelve patients completed the study (mean current age 43.8 ± 12.5 years, 47% male, mean duration of diabetes 22.0 ± 13.2 years) out of 650 randomly selected patients from the Bournemouth Diabetes and Endocrine Centre's diabetes register. The Skills for Life Initial Assessments were used to measure numeracy and literacy. These indicate skills levels up to level 2, equivalent to the national General Certificate of Secondary Education grades A*-C. HbA(1c) was also measured. Pearson's correlation was used to measure the correlation of numeracy and literacy scores with HbA(1c.) To compare mean HbA(1c) between those with or without level 2 skills, t-tests were used, and multiple linear regression was used to investigate whether any differences were independent of duration of diabetes, diabetes education, demographic and socio-economic factors. RESULTS: Literacy was not associated with achieved HbA(1c). In contrast, participants with numeracy skills at level 2 or above achieved an HbA(1c) lower than those with numeracy skills below level 2 (P = 0.027). Although higher socio-economic status was associated with lower mean HbA(1c) , the relationship between numeracy and HbA(1c) appeared to be independent of socio-economic factors. CONCLUSIONS: Low numeracy skills were adversely associated with diabetes control. Assessment of numeracy skills may be relevant to the structure of diabetes education programmes.


Subject(s)
Blood Glucose/metabolism , Diabetes Mellitus, Type 1/blood , Diabetes Mellitus, Type 1/drug therapy , Educational Status , Hypoglycemic Agents/administration & dosage , Self Care , Adult , Diabetes Mellitus, Type 1/epidemiology , Female , Glycated Hemoglobin/metabolism , Humans , Male , Middle Aged , Patient Education as Topic , Self Care/statistics & numerical data , Social Class , United Kingdom
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