A prospective study to assess the effectiveness and safety of the BlueWind System in the treatment of patients diagnosed with urgency urinary incontinence

BACKGROUND

Overactive bladder (OAB) affects one in six adults in Europe and the United States and impairs the quality of life of millions of individuals worldwide. When conservative management fails, third-line treatments including tibial neuromodulation (TNM) is often pursued. TNM has traditionally been accomplished percutaneously in clinic.

OBJECTIVE

A minimally invasive implantable device activated by a battery-operated external wearable unit has been developed for the treatment of urgency urinary incontinence (UUI), mitigating the burden of frequent clinic visits and more invasive therapies that are currently commercially available.

METHODS

A prospective, multicenter, single-arm, open-label, pivotal study evaluated the safety and effectiveness of the device in adult females with UUI (i.e., wet OAB) (BlueWind Implantable Tibial Neuromodulation [iTNM] system; IDE number #G200013; NCT03596671). Results with the device were previously published under the name RENOVA iStim, which has been since renamed as the Revi™ System. Approximately 1-month post-implantation of the device, participants delivered therapy at their convenience and completed a 7-day voiding diary before visits 6- and 12-months post-treatment initiation. The primary efficacy and safety endpoints were the proportion of responders to therapy ( ≥ 50% improvement on average number of urgency-related incontinence episodes) and incidence of adverse events from implantation to 12-month post-activation.

RESULTS

A total of 151 participants, mean age 58.8 (SD: 12.5), were implanted; 144 and 140 completed the 6- and 12-month visits, respectively. The participants demonstrated mean baseline of 4.8 UUI/day (SD 2.9) and 10 voids/day (SD 3.3). Six and 12-months post-activation, 76.4% and 78.4% of participants, respectively, were responders to therapy in an intent-to-treat analysis. Of the 139 participants with completed 12-month diaries, 82% were responders, 50% were classified as "dry" (on at least 3 consecutive diary days), and 93.5% of participants reported that their symptoms improved. No implanted participant experienced an SAE related to the procedure or device.

CONCLUSIONS

iTNM, delivered and powered by a patient-controlled external wearable communicating with an implant, demonstrated clinically meaningful and statistically significant improvement in UUI symptoms and a high safety profile. This therapy highlights the value of patient-centric therapy for the treatment of UUI.

The empty pelvis syndrome: a core data set from the PelvEx collaborative

BACKGROUND

Empty pelvis syndrome (EPS) is a significant source of morbidity following pelvic exenteration (PE), but is undefined. EPS outcome reporting and descriptors of radicality of PE are inconsistent; therefore, the best approaches for prevention are unknown. To facilitate future research into EPS, the aim of this study is to define a measurable core outcome set, core descriptor set and written definition for EPS. Consensus on strategies to mitigate EPS was also explored.

METHOD

Three-stage consensus methodology was used: longlisting with systematic review, healthcare professional event, patient engagement, and Delphi-piloting; shortlisting with two rounds of modified Delphi; and a confirmatory stage using a modified nominal group technique. This included a selection of measurement instruments, and iterative generation of a written EPS definition.

RESULTS

One hundred and three and 119 participants took part in the modified Delphi and consensus meetings, respectively. This encompassed international patient and healthcare professional representation with multidisciplinary input. Seventy statements were longlisted, seven core outcomes (bowel obstruction, enteroperineal fistula, chronic perineal sinus, infected pelvic collection, bowel obstruction, morbidity from reconstruction, re-intervention, and quality of life), and four core descriptors (magnitude of surgery, radiotherapy-induced damage, methods of reconstruction, and changes in volume of pelvic dead space) reached consensus-where applicable, measurement of these outcomes and descriptors was defined. A written definition for EPS was agreed.

CONCLUSIONS

EPS is an area of unmet research and clinical need. This study provides an agreed definition and core data set for EPS to facilitate further research.

Quality of Life and Treatment Modalities in Patients with Interstitial Cystitis: The Patients' Perspective

BACKGROUND

Quality of life (QoL)-based outcomes are hardly incorporated into interstitial cystitis/bladder pain syndrome (IC/BPS) guidelines, because studies are limited and outdated. Therefore, guidelines might not reflect the current clinical situation accurately. Secondly, guidelines suggest using a multimodal approach for BPS/IC management, but data on the patient-perceived efficacy of these therapies are limited. The aim of this study is to investigate the perception of IC/BPS patients of their QoL, to determine which treatments they have received, and to examine how they evaluate the efficacy of these various (alternative) therapies.

METHODS

A quantitative retrospective database evaluation was performed, with data from an existing IC/BPS patient survey (n = 217) that was conducted in 2021. This survey contained QoL data based on validated questionnaires such as EQ-5D 5L.

RESULTS

The QoL of patients is affected significantly by IC/BPS. This is evident from the various affected domains on the EQ-5D 5L. The symptom severity was negatively affected by a delay in diagnosis, and there were clear differences in QoL domains between females and males. Secondly, coagulation therapy and intravesical glycosaminoglycan (GAG) therapy were most appreciated by patients. Other (alternative) treatments were commonly utilized, although some had doubtful results and high discontinuation rates.

CONCLUSION

QoL is considerably impaired in IC/BPS patients. The diverse responses and adherence to various treatments warrant a personalized approach (phenotype-oriented therapy). To achieve QoL improvement, it is important to incorporate the patient's perspective in treatment guidelines.

SATURN: A European, Prospective, Multicentre Registry for Male Stress Urinary Incontinence Surgery

Surgery for male incontinence with artificial urinary sphincters and slings (SATURN) is a prospective, multicentre registry (observational cohort) for male stress urinary incontinence surgery to collect prospective data from multiple European centres and surgeons, to evaluate the short- and long-term success and the impact on quality of life.

The Burden of Urinary Tract Infections on Quality of Life and Healthcare in Patients with Interstitial Cystitis

BACKGROUND

Interstitial cystitis/bladder pain syndrome (IC/BPS) patients are more susceptible to urinary tract infections (UTIs), likely worsening pre-existing symptoms. However, this receives limited attention in guidelines. This study aimed to explore the burden of UTIs on IC/BPS patients' quality of life and their healthcare.

METHODS

Two quantitative retrospective database studies were conducted in cystoscopically proven IC/BPS patients: one compiled existing patient survey data (n = 217) from July 2021 to examine physical and emotional UTI burden, and the other used a patient file database (n = 100) from January 2020 to May 2022, focusing on UTI prevalence, healthcare use, urine cultures and antibiotic resistance.

RESULTS

A delay in diagnosis was seen in 70% of patients, due to doctors confusing IC/BPS symptoms with UTIs. The UTI prevalence was over 50%; these patients also report anxiety for new UTIs (70%) and worsening of IC/BPS symptoms (60%). Additionally, for UTI+ patients, healthcare consumption was significantly increased in both studies. Antibiotic resistance (80% of cultures) and prophylactic antibiotic use were common.

CONCLUSIONS

These findings highlight the burden of UTIs on quality of life in IC/BPS patients and the healthcare system. These results emphasize the need for improved UTI guidelines concerning diagnosis, management and prevention for IC/BPS patients to improve quality of life and care.

Study protocol of a multicentre double-blind RCT, comparing a traditional RCT with an aggregated N-of-1 trial: GAG therapy Efficacy Trial Solution for Bladder pain syndrome/Interstitial cystitis (GETSBI study)

INTRODUCTION

Obtaining level 1 evidence on efficacy of glycosaminoglycan (GAG) therapy is difficult, due to low incidence of bladder pain syndrome/interstitial cystitis (BPS/IC) and heterogeneous symptoms experienced by patients with BPS/IC. Currently, because of a lack of high-grade evidence, the recommendation for applying GAG therapy in most guidelines is 'low grade'. An aggregated N-of-1 trial is a multicrossover design that yields similar level 1 evidence as a traditional randomised controlled trial (RCT), while requiring far less patients. The goal of this study is to investigate the efficacy of intravesical GAG therapy (Ialuril) for patients with BPS/IC with Hunner lesions using a dual RCT and aggregated N-of-1 trial design to obtain level 1 evidence.

METHODS AND ANALYSIS

The GETSBI study is a double-blind multidesign multicentre randomised placebo-controlled study to assess the short-term and long-term efficacy of hyaluronic acid (1.6%) + chondroitin sulfate (2%) therapy (Ialuril Prefill, IBSA, Goodlife) in patients with symptomatic BPS/IC with Hunner lesions. It starts as a standard RCT (n=80), but continues as an aggregated N-of-1 trial. There are three parallel arms, receiving blinded treatment for three periods (1 x/week for 6 weeks, ratio placebo to intervention in periods of 2:1). Followed by an open prospective part for the long-term efficacy. The primary study outcome is the maximum bladder pain experienced in the last 3 days measured using the visual analogue pain scale (0-10).This study is a collaboration with the Dutch government and will deliver evidence for the decision to reimburse the therapy. Furthermore, this multidesign study will allow us to compare the two main methods to evaluate applicability for future study designs for BPS/IC research.

ETHICS AND DISSEMINATION

Ethical approval was given by METC Oost-Nederland, file number: 2020-7265, NL-number: NL76290.091.20. Findings from this study will be disseminated via publication, reports and conference presentations.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov identifier (NCT number): NCT05518864.

[Depressive and anxiety symptoms in hereditary connective tissue disorders : case description and systematic literature review]

Hereditary connective tissue disorders are a broad group of congenital disorders that are characterized by a pathological weakness of the connective tissue as a result of an incorrect genesis, leading to multisystem complaints. We describe a 14-year-old patient with the hereditary connective tissue disorder Loeys-Dietz syndrome who was admitted to a child psychiatric crisis unit because of depressive and anxiety symptoms. A systematic literature search was carried out to analyze the prevalence of depressive and anxiety symptoms in individuals with hereditary connective tissue disorders Loeys-Dietz syndrome, Ehlers-Danlos syndrome and Marfan syndrome, to identify a possible association between these disorders and explanations for this. We conclude that there is an increased incidence of depression and anxiety symptoms in which pain, fatigue, social support and functioning, quality of life and functional limitations seem to play a role. There is a need for further research to determine exactly which factors contribute and how these can be targeted in prevention and treatment.

Prevalence of reaching target low-density lipoprotein cholesterol (LDL-C) in very high-risk patients using high intensity lipid-modifying therapy

Background

Hyperlipidemia is an important risk factor for developing cardiovascular disease. Lowering LDL-C reduces the risk for coronary heart disease: the longer LDL-C remains low, the better. We studied the effect of implementing a guideline based, stepwise approach of lipid-modifying therapy to achieve target LDL-C levels in very high-risk patients in daily clinical practice in the Netherlands.

Methods

Nine hundred and ninety-nine (999) patients with a type I (N)STEMI and a history of Atherosclerotic Cardiovascular Disease and/or Diabetes mellitus II were included. Patients with LDL-C >1.8 mmol/L were treated with high-intensity statin (HIST) monotherapy. If target LDL-C level was not reached, first ezetimibe and subsequently a PCSK9i was added. The primary objective was to assess the prevalence of reaching LDL-C ≤1.8mmol/L with HIST and/or ezetimibe.

Results

Nine hundred and thirty-nine (939) patients were treated with HIST and/or ezetimibe, of whom 89% reached LDL-C ≤1.8 mmol/L. Yet thirty four (34) of the 40 patients (85%) who received additional treatment with PCSK9i, reached the target LDL. After treatment with HIST, HIST plus ezetimibe, and HIST plus ezetimibe and PCSK9i in the per protocol population the cumulative prevalence of reaching target LDL-C was 71%, 89% and 99% respectively.

Conclusion

Using an ESC guideline-based flowchart with stepwise intensification of lipid-lowering drugs, using HIST and/or ezetimibe, 89% of the very high-risk patients reached an LDL-C ≤1.8 mmol/L in 57 days ± 38 (mean ± SD). Including patients in whom additional PCSK9i was started, success rate of meeting target LDL-C rose to 99%.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Sanofi-Aventis Netherlands B.V.

Patient-tailored healthcare and tibial nerve neuromodulation in the treatment of patients with overactive bladder symptoms

Purpose

The aim of this study was to demonstrate features predictive of treatment response for patient‐tailored overactive bladder (OAB) intervention with an implantable tibial neurostimulator using patient and technical prediction factors.

Materials and Methods

This study was designed as a follow‐up study based on parameter settings and patients' preferences during the pilot and extended study of the implantable tibial nerve stimulator (RENOVA™ iStim system). For this study, we compared all treatment parameters (stimulation amplitude, frequency, and pulse width) and usage data (duration of treatment) during the different follow‐up visits.

Results

We obtained usage data from a total of 32 patients who were implanted with the system between February and September 2015. Age, sex, body mass index (BMI) and previous experience with percutaneous tibial nerve stimulation (PTNS) treatment were considered as possible prediction factors for treatment success. However, only BMI was considered a statistically significant prediction factor (p = 0.042). A statistically significant increase in mean treatment level was seen in the responder group during the 3 month follow‐up visit (mean: 6.7 mA, SD 0.416) as compared with the initial system activation visit (mean: 5.8 mA, SD 0.400) (p = 0.049). No other visits demonstrated statistically significant changes in both groups (responders and nonresponders) during the defined timepoints.

Conclusion

This data underscores the need to use patient‐tailored OAB treatment. BMI was found to be a negative predictive factor for treatment success. However, it was not possible to develop a specific responder model. A model predicting response to treatment could be useful for implementing shared decision making.

Vesico-Vaginal Fistula Repair by a Vaginal Approach

INTRODUCTION

The aim of this study is to determine the outcome of surgically treated vesico-vaginal fistulae (VVaFs) using a transvaginal approach with a Latzko technique.

METHODS

A retrospective chart study was conducted at the Department of Urology, Radboud University Medical Centre. Surgical approaches to repair VVaF, from 2014 to September 2020, were selected. Patients who underwent a transvaginal approach were included. The primary objective was fistula closure. Secondary objectives were predictive factors for the outcome of the surgical procedure, for example, patient characteristics, leakage on cystography 2 weeks postoperative, and surgery time.

RESULTS

Thirty-one patients had surgery for VVaF. Twenty-five procedures (81%) were performed transvaginally. Thirteen of these (52%) had successful transvaginal closure after the first attempt. Seven out of 12 had their second attempt at the time of analysis, of which 4 (57%) were successfully closed thereafter. After either 1 or 2 attempts with the transvaginal approach, 17 (68%) of the VVaFs were successfully closed, but 79% if patients who did not yet had a second attempt were taken into account with the current success extrapolated. Only few minor complications were observed.

CONCLUSION

Transvaginal closure of VVaFs with a Latzko technique is successful in about 79% in either 1 or 2 attempts, with few minor complications. A second attempt in closing the fistula with a transvaginal approach is useful, and a previous transvaginal attempt is not a contraindication for a second transvaginal attempt in closing the VVaF surgically.

Real-life patient experiences of TTNS in the treatment of overactive bladder syndrome

Introduction and objectives:

Overactive bladder syndrome (OAB) is defined as urinary urgency, with or without urgent urinary incontinence; it is often associated with urinary frequency and nocturia, in the absence of any pathological or metabolic conditions that may cause or mimic OAB. The aim of this study was to evaluate the long-term real-life adherence of transcutaneous tibial nerve stimulation (TTNS) in the treatment of OAB, patient satisfaction of the treatment, and reasons for quitting therapy.

Materials and methods:

In this single center study, all patients who had a positive effect on percutaneous tibial nerve stimulation (PTNS) and continued to receive home-based treatment with TTNS since 2012 were included for analysis. Patients were retrospectively asked to fill out a questionnaire regarding satisfaction, reasons for quitting, and additional or next line of therapy.

Results:

We included 42 patients for this study, 81% of these patients were female (n = 34). The median age was 67 years (range 36–86). Most of the patients (64%, n = 27) were diagnosed with OAB wet. The median TTNS treatment persistence was 16 months (range 1–112 months). Reasons and percentages for stopping therapy were: 55% stopped treatment due to loss of effect, and 24% stopped because of preferring other type of neuromodulation. The mean satisfaction score (scale 1–10) in patients who continued TTNS was 6.2 (n = 9, SD 1.30) versus 5.4 (n = 29, SD 2.24) for patients who quit therapy. We did not find a statistically significant difference between the two groups (p = 0.174).

Conclusion:

TTNS, although effective in the short-term, is not effective in the long-term. In combination with a low satisfaction rate among patients, there is a need for improvement in terms of OAB treatment modalities.

Is the value of urodynamics undermined by poor technique?: ICI-RS 2018

INTRODUCTION

The quality of urodynamic measurements in clinical practice has been debated as a matter of concern. It is considered plausible that this has a direct bearing on patient care and the perceived value of urodynamic testing.

METHODS

This is a report of the proceedings of the Think Tank: "Is the value of urodynamics undermined by poor technique?" from the Annual International Consultation on Incontinence-Research Society, which took place in June 2018 in Bristol, UK. The Think Tank discussed the evidence for deficiencies in urodynamic test quality and considered the implications of improvements for clinical diagnosis and practice.

RESULTS

There is evidence that technique affects urodynamic quality, and that urodynamic practice is variable. Factors such as team skill set, technologies used, and training received will also affect the quality of urodynamic service. Questions exist regarding the influence of technique on the utility and perceived value of urodynamics.

CONCLUSIONS

We suggest research questions that will provide the necessary evidence on the link between technique, reporting, and outcome, and clarify the role of good practice in the utility of urodynamic testing.

Detrusor Underactivity and Underactive Bladder in Women: What Is New?

Purpose of Review

Detrusor underactivity (DU) and its symptom-based correlation, the underactive bladder (UAB), are common problems encountered in urological practice. Whilst DU has been defined for many years, only recently has UAB received a formal definition and there is now accumulating literature based on this condition. In this article, we reviewed the recent literature on the aetiology, pathogenesis, diagnosis and management of DU/UAB in women.

Recent Findings

Detrusor underactivity is diagnosed on urodynamic studies but there still remains a lack of widely recognised and accepted diagnostic criteria. Commencing treatment based on the diagnosis of UAB, with or without a PVR measurement, is perhaps feasible due to the lower occurrence of BOO in women and specific clinical features that may distinguish this group. Prospective studies attempting to correlate UAB with the underlying DU are needed before this approach could be considered.

Summary

Detrusor underactivity/UAB in women requires a separate consideration from men due to the anatomical and functional differences in the lower urinary tracts between both genders and consequent differences in pathologies affecting them. The aetiology of DU remains largely unknown, but is probably multifactorial, including myogenic, neurogenic and vasculogenic factors. There remains a lack of any simple effective drug treatments, whilst apart from sacral neuromodulation for the specific subgroup with non-obstructive urinary retention, no safe and effective surgical treatment is currently available. Often, permanent or intermittent bladder drainage with a catheter is the final solution.

Urinary gonadotropin measurements in neonates: a valuable non-invasive method

Background: To measure low neonatal gonadotropin levels, a sensitive non-invasive method is optimal. The aim of the current study was to validate the Architect i2000SR, an automated immunoassay analyser for the measurement of gonadotropins in unextracted neonatal urine samples against serum gonadotropin levels as a gold standard.

Methods: Blood and urine were sampled from 30 approximately six-week-old male and female neonates undergoing elective paediatric surgery. Follicle stimulating hormone (FSH) and luteinizing hormone (LH) were measured and the urine results were corrected for creatinine.

Results: The agreement between neonatal serum and urinary FSH was 0.904 (3-5 h between samples) and 0.704 (18-20 h). For LH, the correlation coefficients were 0.785 and 0.507, respectively.

Conclusion: We conclude that gonadotropins can be reliably measured using the Architect on randomly voided, non-extracted urine samples collected from neonates by an adhesive device. Urinary gonadotropin levels are a proper reflection of the serum levels.

Clinical Experience in the Therapy of Bites from Exotic Snakes in Berlin

Since there are nearly no indigenous poisonous snakes in Germany, snake bites by poisonous snakes are rare. Most serious snake bites reported to poison information centres or treated at hospitals are caused by exotic snakes that are kept in private households. Only few types of antivenom are stored in emergency depots in Germany including polyvalent antivenoms from commercial sources. Since experience with the treatment of poisonous snake bites is limited, the records of the Intensive Care Unit and the Poison Information Centre of the Universitätsklinikum Rudolf Virchow from 1980-1991 were evaluated. During this period, 51 snake bites were reported. Eleven patients who had been bitten by exotic poisonous snakes were treated in intensive care. In eight of the cases, ethanol (blood levels on admission 1.2-4.2 g-1) had played an important role in the cause of the bite. A moderate to severe local inflammation at the site of the bite followed by oedema and necrosis was typical. One patient developed respiratory failure, probably because of the neurotoxic effects of the snake venom and a compartment syndrome necessitating fasciotomy. Haemolysis was observed in four patients and coagulopathy in six patients. All patients received polyvalent antivenom within 2-12 h of the snake bite. Despite serious coagulopathy in two of the patients and respiratory arrest in one, all survived without sequelae.

An estimated glomerular filtration rate equation for the full age spectrum

BACKGROUND

Glomerular filtration rate (GFR) is accepted as the best indicator of kidney function and is commonly estimated from serum creatinine (SCr)-based equations. Separate equations have been developed for children (Schwartz equation), younger and middle-age adults [Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation] and older adults [Berlin Initiative Study 1 (BIS1) equation], and these equations lack continuity with ageing. We developed and validated an equation for estimating the glomerular filtration rate that can be used across the full age spectrum (FAS).

METHODS

The new FAS equation is based on normalized serum creatinine (SCr/Q), where Q is the median SCr from healthy populations to account for age and sex. Coefficients for the equation are mathematically obtained by requiring continuity during the paediatric-adult and adult-elderly transition. Research studies containing a total of 6870 healthy and kidney-diseased white individuals, including 735 children, <18 years of age, 4371 adults, between 18 and 70 years of age, and 1764 older adults, ≥70 years of age with measured GFR (inulin, iohexol and iothalamate clearance) and isotope dilution mass spectrometry-equivalent SCr, were used for the validation. Bias, precision and accuracy (P30) were evaluated.

RESULTS

The FAS equation was less biased [-1.7 (95% CI -3.4, -0.2) versus 6.0 (4.5, 7.5)] and more accurate [87.5% (85.1, 89.9) versus 83.8% (81.1, 86.5)] than the Schwartz equation for children and adolescents; less biased [5.0 (4.5, 5.5) versus 6.3 (5.9, 6.8)] and as accurate [81.6% (80.4, 82.7) versus 81.9% (80.7, 83.0)] as the CKD-EPI equation for young and middle-age adults; and less biased [-1.1 (-1.6, -0.6) versus 5.6 (5.1, 6.2)] and more accurate [86.1% (84.4, 87.7) versus 81.8% (79.7, 84.0)] than CKD-EPI for older adults.

CONCLUSIONS

The FAS equation has improved validity and continuity across the full age-spectrum and overcomes the problem of implausible eGFR changes in patients which would otherwise occur when switching between more age-specific equations.

Application of the Characteristic Function to Evaluate and Compare Analytical Variability in an External Quality Assessment Scheme for Serum Ethanol

BACKGROUND

As a cornerstone of quality management in the laboratory, External Quality Assessment (EQA) schemes are used to assess laboratory and analytical method performance. The characteristic function is used to describe the relation between the target concentration and the EQA standard deviation, which is an essential part of the evaluation process. The characteristic function is also used to compare the variability of different analytical methods.

METHODS

We fitted the characteristic function to data from the Belgian External Quality Assessment program for serum ethanol. Data included results from headspace gas chromatography and the enzymatic methods of Abbott, Roche, Siemens, and Ortho-Clinical Diagnostics. We estimated the characteristic function with weighted nonlinear regression. By introducing dummy variables, we rewrote the original formula of the characteristic function to assess statistical inference for comparing the variability of the different analytical methods.

RESULTS

The characteristic function fitted the data precisely. Comparison between methods showed that there was little difference between the estimated variability for low concentrations, and that the increase in SD with increasing target concentration was slower for Abbott and Roche than for the other methods.

CONCLUSIONS

The characteristic function can successfully be introduced in clinical schemes, although its applicability to fit the data should always be assessed. Because of its easy parameterization, it can be used to assess differences in performance between analytical methods and to assess laboratory performance. The characteristic function also offers an alternative framework for coefficients of variation to describe variability of analytical methods.

Routine serum creatinine measurements: how well do we perform?

BACKGROUND

The first aim of the study was to investigate the accuracy and intra-laboratory variation of serum creatinine measurements in clinical laboratories in Flanders. The second purpose was to check the effect of this variation in serum creatinine concentration results on the calculated estimated glomerular filtration rate (eGFR) and the impact on classification of patients into a chronic kidney disease (CKD) stage.

METHODS

26 routine instruments were included, representing 13 different types of analyzers from 6 manufacturers and covering all current methodologies (Jaffe, compensated Jaffe, enzymatic liquid and dry chemistry methods). Target values of five serum pools (creatinine concentrations ranging from 35 to 934 μmol/L) were assigned by the gold standard method (ID-GC/MS).

RESULTS

Intra-run CV (%) (n = 5) and bias (%) from the target values were higher for low creatinine concentrations. Especially Jaffe and enzymatic dry chemistry methods showed a higher error. The calculated eGFR values corresponding with the reported creatinine concentration ranges resulted in a different CKD classification in 47% of cases.

CONCLUSIONS

Although most creatinine assays claim to be traceable to the gold standard (ID-GC/MS), large inter-assay differences still exist. The inaccuracy in the lower concentration range is of particular concern and may lead to clinical misinterpretation when the creatinine-based eGFR of the patient is used for CKD staging. Further research to improve harmonization between methods is required.

Does the type of creatinine assay affect creatinine clearance determination?

BACKGROUND

A creatinine clearance (CrCl) is still often requested to estimate the glomerular filtration rate (GFR) in clinical practice. However, the diversity of serum and urine creatinine (Scr, Ucr) assays leads to different CrCl-results which are here compared with each other and with the CKD-EPI eGFR-formula.

METHODS

We collected information on urine volume, Ucr and Scr using Roche's enzymatic (E), compensated Jaffe (CJ) and Jaffe (J) assay for 589 patients. To allow comparison with the CKD-EPI prediction results, CrCl was normalized for body surface area.

RESULTS

Differences between CrCl-E and CrCl-CJ are rather small as opposed to the large differences with CrCl-J. However, two compensating errors in the CrCl-J calculation result in a closer agreement with CKD-EPI eGFR, than between CrCl-CJ or CrCl-E and CKD-EPI eGFR. The explained variance R(2) in all three cases is smaller than 0.66, demonstrating the very large scatter of the data around the regression line.

CONCLUSIONS

CrCl determination is very assay-dependent. Although many clinical labs have switched to ID-GC/MS-standardized assays (E and CJ) for the determination of Scr and Ucr to improve analytical accuracy, the increased deviation of the normalized CrCl from the CKD-EPI prediction illustrates that the use of CrCl remains questionable for clinical practice. When a CrCl is requested, we would even recommend clinical labs who work with compensated Jaffe assays not to compensate the Scr-J value.

Determination des metabolites monoester de butylbenzyl-phthalate (bbp) par gcms dans les urines de personnes exposees: analysis of the monoester metabolites of butylbenzyl phthalate by gc-ms in urine of exposed workers

A method of analysis was developed to determine free and glucuronated monobutyl phthalate (BuP) and monobenzyl phthalate (BeP) in urine for the assessment of exposure of man to butylbenzyl phthalate (BBP) in the workplace and in the environment. This method has also been applied in pharmacokinetic studies in experimental animals and the determination in urine of exposed workers. Urine samples are first subjected to enzymatic hydrolysis with ß-glucuronidase to enable the measurement of the total amount of monophthalates excreted. A fraction of the hydrolysate is used for further analysis. Monohexyl phthalate is added as an internal standard and the hydrolysed urine extracted with a n-hexane/ dichloromethane mixture after acidification and saturation with salt. The organic fractions are washed, dehydrated and evaporated. The residue is methylated by means of diazomethane dissolved in diethylether, evaporated and further purified by extraction into n-hexane from an alkaline buffer. The organic fractions are evaporated and the residue redissolved in acetonitrile for analysis by ion trap GC-MS equipped with a 50 m apolar WCOT capillary column. TIC mass chromatograms are recorded from which SIM chromatograms can be derived electronically. The m/z values used are 91, 149, and 163 which provide a sufficient sensitive response and which are specific enough to pick up the methylated monophthalates under investigation. The quantitative limit of detection (LOQ) is 60 μg/L for BuP and BeP when using the Magnum ion Trap detector and 3 μg/L when using the Polaris Q in the splitless mode. The calibration curve in urine is linear from 120 μg/L to 50,000 μg/L with a coefficient of variation of less than 10 % . In case of the Polaris Q linearity started from 10 μg/L. The recovery of the method is monitored by the response signal of the internal standard in the ion chromatogram. In the event of insufficient recovery the analysis is repeated. Variations in recovery are compensated by the internal standard of which the molecular structure is very similar to the ones of the monophthalates under investigation.

[Treatment practice in patients with isolated blunt splenic injuries. A survey of Swiss traumatologists]

BACKGROUND

The non-operative management (NOM) of blunt splenic injuries has gained widespread acceptance. However, there are still many controversies regarding follow-up of these patients. The purpose of this study was to survey active members of the Swiss Society of General and Trauma Surgery (SGAUC) to determine their practices regarding the NOM of isolated splenic injuries.

MATERIALS AND METHODS

A survey of active SGAUC members with a written questionnaire was carried out. The questionnaire was designed to elicit information about personal and facility demographics, diagnostic practices, in-hospital management, preferred follow-up imaging and return to activity.

RESULTS

Out of 165 SGAUC members 52 (31.5%) completed the survey and 62.8% of all main trauma facilities in Switzerland were covered by the sample. Of the respondents 14 (26.9%) have a protocol in place for treating patients with splenic injuries. For initial imaging in hemodynamically stable patients 82.7% of respondents preferred ultrasonography (US). In cases of suspected splenic injury 19.2% of respondents would abstain from further imaging. In cases of contrast extravasation from the spleen half of the respondents would take no specific action. For low-grade injuries 86.5% chose to admit patients for an average of 1.6 days (range 0-4 days) with a continuously monitored bed. No differences in post-discharge activity restrictions between moderate and high-grade splenic injuries were found.

CONCLUSION

The present survey showed considerable practice variation in several important aspects of the NOM of splenic injuries. Not performing further CT scans in patients with suspected splenic injuries and not intervening in cases of a contrast extravasation were the most important discrepancies to the current literature. Standardization of the NOM of splenic injuries may be of great benefit for both surgeons and patients.

A new equation to estimate the glomerular filtration rate in children, adolescents and young adults

BACKGROUND

A new estimated glomerular filtration rate (eGFR) equation, designed for isotope dilution mass spectrometry-standardized serum creatinine (Scr), is presented for use in children, adolescent boys and girls and young adults.

METHODS

The new equation, eGFR = 107.3/(Scr/Q), is based on the concept of normalized Scr: Q is the normalization value and is considered as the Scr concentration for the average healthy child, adolescent or young adult of a specific height (L) and is modeled as a height-dependent polynomial of the fourth degree.

RESULTS

The well-known Schwartz equation [eGFR = kL/Scr, k = 0.413 (Schwartz) or k = 0.373 (Schwartz-Lyon)] for children between 1 and 14 years can be seen as a special case of the new equation for which the Q-polynomial is simplified to a linear equation: Q = 0.0035 × L (cm). The new eGFR equation has been validated in a data set of n = 750 children, adolescents and young adults aged 10-25, against the true GFR (inulin method), and outperforms the selected (but most used) creatinine-based eGFR equations for children, mainly in the healthy GFR region.

CONCLUSIONS

The new Q(height)-eGFR equation serves as an excellent screening tool for kidney disease in 1-25-year-old children, adolescents and young adults.

A simple height-independent equation for estimating glomerular filtration rate in children

BACKGROUND

The chronic kidney disease (CKD) classification system for children is similar to the CKD classification system for adults, using estimated glomerular filtration rate (eGFR) combined with fixed cut-off values of 60, 30, and 15 ml/min/1.73 m(2) for CKD stages III, IV, and V, respectively. To estimate GFR in children, eGFR-equations are used that require serum creatinine (Scr), but also height information, which is normally not available in clinical laboratory databases.

METHODS

This retrospective study is based on data from two different databases, one that has previously been used to develop the Flanders Metadata equation for children and one database including 353 children who underwent (51)Cr-EDTA GFR, serum creatinine, height, and weight measurements.

RESULTS

A height-independent eGFR equation based on the concept of a population-normalized Scr, presented before for adults, is extended to children: eGFR = 107.3/(Scr/Q), with Q the median Scr for healthy children of a particular age. This equation is validated against direct measurements of GFR, and against the updated Schwartz and Flanders Metadata equation.

CONCLUSIONS

The new simple height-independent equation performs very well and should make (mass) screening of kidney function in children easier.

Demystifying ethnic/sex differences in kidney function: is the difference in (estimating) glomerular filtration rate or in serum creatinine concentration?

BACKGROUND

The recent evaluation of the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation for estimating the glomerular filtration rate (GFR) in multiple ethnicities has raised the question on how well this equation performs for African-American and Asian subjects. There is no doubt that serum creatinine (Scr) concentration differs between ethnicities and sexes. We show that creatinine-based equations for white populations may be inaccurate for estimating GFR in other ethnic/gender groups, especially in populations from Asia.

METHODS

This study presents a mathematical analysis of the CKD-EPI-equation complemented with a literature review of median and reference values for IDMS-standardized Scr-concentrations for multiple ethnicities.

RESULTS

The study shows that at equal eGFR-CKD-EPI-values, the ratio of Scr between females and males equals 0.79 and between other ethnicities/sexes and white males is constant too. From this information, it is possible to calculate mean Scr-values that correspond very well with literature values directly obtained from Scr-distributions in healthy white males and females and in black males, but the discrepancy is larger for other populations.

CONCLUSIONS

Our results confirm the criticism that has been raised for using the CKD-EPI-equation for these ethnicities. An alternative eGFR-model is proposed based on a population-normalized Scr that needs further validation.

Iceman Survived due to Cooling Device

Although mild hypothermia treatment is part of the standard postresuscitation care today, no standard method for treatment of accidental severe hypothermia has been yet established. Different strategies including invasive and noninvasive methods have been described in the literature. We present the case of a 75-year-old man with accidental severe hypothermia (23°C) and demonstrate that using a surface cooling device with automatic controlled temperature feedback mechanism (ArcticSun2000 Medivance, Louisville, Colorado, USA) is an effective and safe method for controlled rewarming in this life-threatening setting.

A comprehensive LC-MS-based quantitative analysis of fentanyl-like drugs in plasma and urine

Fentanyl, norfentanyl, alfentanil, sufentanil, remifentanil and 3-methylfentanyl are potent, short-acting, synthetic narcotic analgesics that are not revealed in standard opiate immunoassays. In this article, a fully validated analytical method for the determination of these fentanyl-type compounds in plasma and urine is presented, consisting of a liquid-liquid extraction followed by a LC-MS/MS analysis using electrospray ionisation in the positive ionisation mode. Fentanyl-d(5) and norfentanyl-d(5) were used as internal standards. The lower LOQ in plasma and urine was 0.1 ng/mL for fentanyl, norfentanyl, alfentanil, remifentanil and 3-methylfentanyl, and 0.2 ng/mL for sufentanil. The method proved linear over a concentration range of 0.2-50 ng/mL for sufentanil and 0.1-50 ng/mL for all other analytes, with correlation coefficients of 0.998 or better. The analytical procedure showed excellent selectivity and precision (all CVs below 15%) for all analytes. Accuracy was good, except for sufentanil, where deviations of more than 15% from nominal concentrations were observed. No matrix effects were observed, and stability of stock and internal standard solutions was within acceptability limits.

New insights in glomerular filtration rate formulas and chronic kidney disease classification

BACKGROUND

The MDRD Study equation is the most popular equation for estimating the glomerular filtration rate (eGFR) from serum creatinine (Scr), age, sex and race. Many articles deal with ethnic factors, correcting the MDRD Study equation for different populations, with more or less success. The new CKD-EPI equation introduced the concept of a population-normalized Scr in the eGFR equation for white men (Scr/0.90) and white women (Scr/0.70).

METHODS

We introduce alternative mathematical forms for the MDRD Study equation and the CKD-EPI equation, using the concept of a population-normalized Scr, resulting in a more general and mathematically less complicated form for the eGFR equation.

RESULTS

We show that the normalization constant corresponds to the mean Scr-value for the specific healthy population. We compared the established equations with the new alternative forms, and show that the differences are minimal. The sex/race dependency is completely comprehended in the normalization constant, making the alternative eGFR equations independent of sex and race.

CONCLUSION

The age-dependency of eGFR remains and consequently age-dependent cutoff values for the classification of Chronic Kidney Disease (CKD) look more appropriate, contrary to the current classification rules. The population-normalized Scr which is independent of age, sex and race may serve as an alternative for the classification of CKD.

On the relationship between glomerular filtration rate and serum creatinine in children

The Schwartz formula (eGFR = kL/Scr, with k = 0.55) to determine the estimated glomerular filtration rate (eGFR) in children with chronic kidney disease (CKD), based on length (L) and serum creatinine (Scr) has recently been updated for enzymatic serum creatinine concentrations, resulting in k = 0.413. Based on a meta-analysis, we evaluated the validity of this updated equation and other published equations for healthy children. This is the first time that publicly available data for healthy children of uncorrected and body surface area (BSA)-corrected median GFR have been combined with median serum creatinine values and median lengths and weights from different sources in the literature to evaluate several statistical models to estimate GFR in children. For enzymatic serum creatinine, we show that the simple model for uncorrected GFR (uGFR = k'L(3)/Scr, with k' = 1.32 x 10(-5)) and the BSA-corrected GFR (cGFR = kL/Scr, analogous to the Schwartz formula), with an important age-dependent adaptation for k (k = 0.0414 x 1n (Age) + 0.3018), correlate extremely well with chromium-51-ethylenediamine tetra-acetic acid ((51)Cr-EDTA) data for children between 1 month and 14 years of age. With this age-dependent modification for k, presented here, the simple bedside calculation tool derived by Schwartz can be used for screening all children for CKD. When height information is not available, the Lund-Malmö equation is an excellent alternative.

Mild therapeutic hypothermia alters neuron specific enolase as an outcome predictor after resuscitation: 97 prospective hypothermia patients compared to 133 historical non-hypothermia patients

INTRODUCTION

Neuron specific enolase (NSE) has been proven effective in predicting neurological outcome after cardiac arrest with a current cut off recommendation of 33 microg/l. However, most of the corresponding studies were conducted before the introduction of mild therapeutic hypothermia (MTH). Therefore we conducted a study investigating the association between NSE and neurological outcome in patients treated with MTH.

METHODS

In this prospective observational cohort study the data of patients after cardiac arrest receiving MTH (n = 97) were consecutively collected and compared with a retrospective non-hypothermia (NH) group (n = 133). Serum NSE was measured 72 hours after admission to ICU. Neurological outcome was classified according to the Pittsburgh cerebral performance category (CPC 1 to 5) at ICU discharge.

RESULTS

NSE serum levels were significantly lower under MTH compared to NH in univariate analysis. However, in a linear regression model NSE was affected significantly by time to return of spontaneous circulation (ROSC) and ventricular fibrillation rhythm but not by MTH. The model for neurological outcome identified NSE, NSE*MTH (interaction) as well as time to ROSC as significant predictors. Receiver Operating Characteristic (ROC) analysis revealed a higher cutoff value for unfavourable outcome (CPC 3 to 5) with a specificity of 100% in the hypothermia group (78.9 microg/l) compared to the NH group (26.9 microg/l).

CONCLUSIONS

Recommended cutoff levels for NSE 72 hours after ROSC do not reliably predict poor neurological outcome in cardiac arrest patients treated with MTH. Prospective multicentre trials are required to re-evaluate NSE cutoff values for the prediction of neurological outcome in patients treated with MTH.

Establishing age/sex related serum creatinine reference intervals from hospital laboratory data based on different statistical methods

BACKGROUND

This is a retrospective study on a large hospital database to establish age- and sex-related mean values and reference ranges for serum creatinine (Scr), obtained with an IDMS-traceable, enzymatic method, in a Caucasian population.

METHODS

The database was filtered for unique entries to reduce the presence of correlated and pathological data. Three different statistical methods, a non-parametric method, the Bhattacharya procedure and a non-linear fit of the cumulative Gaussian distribution were used to estimate the serum creatinine-age dependency for men and women, from birth till 100 years of age.

RESULTS

Scr increases with age, equal for boys and girls, up to 14 years and with a much steeper slope for boys than for girls between 14 and 20 years. We show that the Scr-age pattern is constant between 20 and 70 years with a mean of 0.90 mg/dL [0.63-1.16 mg/dL] for men and 0.70 mg/dL [0.48-0.93 mg/dL] for women. Above 70, Scr starts to slowly increase again.

CONCLUSIONS

Indirect methods confirm the available reference intervals from healthy-volunteer studies and add information on age-periods not covered by these studies. As such, indirect methods can be used complementary to healthy-volunteer studies.

Acute myocardial infarction caused by coronary tumor thromboembolism: a rare primary manifestation of malignant tumor disease

Myocardial infarction in the context of malignant tumor disease is rare but well documented and can occur through various pathophysiological mechanisms. We report an unusual case of a patient with recurrent myocardial infarction due to coronary tumor thromboembolism as the first clinical manifestation of a previously unknown squamous cell carcinoma of the lung. The possible pitfalls leading to a wrong preliminary diagnosis in our case as well as the literature on myocardial infarction in patients with cancer were discussed.

Basal FSH concentrations as a marker of ovarian ageing are not related to pregnancy outcome in a general population of women over 30 years

BACKGROUND

Previous studies suggest that elevated basal FSH concentrations are related to aneuploid pregnancies. However, there have been no prospective studies evaluating the incidence of aneuploidies in relation to basal FSH concentrations. Since the majority of aneuploid conceptions end in early pregnancy loss or abortion of a recognized pregnancy, these determinants are appropriate intermediate end-points to study aneuploidy.

METHODS

We performed a prospective study in 129 women without a history of subfertility pursuing a spontaneous pregnancy. Basal FSH concentrations were measured during three menstrual cycles. Urinary HCG levels were measured during menstruation for a maximum of six menstrual cycles, to detect early pregnancy loss. We estimated the effect of basal FSH concentrations on pregnancy outcome, taking into account possible confounders.

RESULTS

We observed no significant effect of basal FSH concentrations on the incidence of early pregnancy loss or abortion of clinically recognized pregnancies.

CONCLUSIONS

We conclude that in a population of women without a history of subfertility, pursuing a spontaneous pregnancy, basal FSH concentrations are not related to the incidence of early pregnancy loss or abortions. This prospective study therefore fails to confirm a relationship between signs of decreased ovarian reserve and aneuploid pregnancies.

Miliaria crystallina in an intensive care setting

Drop-like, transient blisters of miliaria crystallina may develop with focal intensity of heat within the skin, such as occurs in tropical climates or during febrile episodes. Miliaria crystallina develops due to a transient poral closure of the sweat duct opening, resulting in obstruction of free flow of eccrine sweat and retention in a vesicle below the skin surface. Dual cholinergic and adrenergic sweat gland innervation is influenced by a variety of medications used in intensive care patients. We present two febrile intensive care patients in whom enhanced alpha-adrenergic stimulation of sweat gland myoepithelia may have led to miliaria crystallina.

[Determination of monoester metabolites of butylbenzyl phthalate (BBP) by GC-MS in the urine of exposed workers]

A method of analysis was developed to determine free and glucuronated monobutyl phthalate (BuP) and monobenzyl phthalate (BeP) in urine for the assessment of exposure of man to butylbenzyl phthalate (BBP) in the workplace and in the environment. This method has also been applied in pharmacokinetic studies in experimental animals and the determination in urine of exposed workers. Urine samples are first subjected to enzymatic hydrolysis with beta-glucuronidase to enable the measurement of the total amount of monophthalates excreted. A fraction of the hydrolysate is used for further analysis. Monohexyl phthalate is added as an internal standard and the hydrolysed urine extracted with a n-hexane/dichloromethane mixture after acidification and saturation with salt. The organic fractions are washed, dehydrated and evaporated. The residue is methylated by means of diazomethane dissolved in diethylether, evaporated and further purified by extraction into n-hexane from an alkaline buffer. The organic fractions are evaporated and the residue redissolved in acetonitrile for analysis by ion trap GC-MS equipped with a 50 m apolar WCOT capillary column. TIC mass chromatograms are recorded from which SIM chromatograms can be derived electronically. The m/z values used are 91, 149, and 163 which provide a sufficient sensitive response and which are specific enough to pick up the methylated monophthalates under investigation. The quantitative limit of detection (LOQ) is 60 micrograms/L for BuP and BeP when using the Magnum ion Trap detector and 3 micrograms/L when using the Polaris Q in the splitless mode. The calibration curve in urine is linear from 120 micrograms/L to 50,000 micrograms/L with a coefficient of variation of less than 10%. In case of the Polaris Q linearity started from 10 micrograms/L. The recovery of the method is monitored by the response signal of the internal standard in the ion chromatogram. In the event of insufficient recovery the analysis is repeated. Variations in recovery are compensated by the internal standard of which the molecular structure is very similar to the ones of the monophthalates under investigation.