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Biomedical subjects

G S Sonke

Publications and source records attributed to G S Sonke.

17 recordsLinked to original sources
PubMed2006

Prevalence and clinical significance of an elevated cardiac troponin I in patients presenting to the Emergency Department without chest pain.

BACKGROUND: Cardiac troponins are currently measured in patients presenting with chest pain. Little is known about routinely measured cardiac troponins in patients presenting without chest pain. The aim of this study was to determine the prevalence and clinical significance of an elevated cardiac troponin I (cTnI) in patients presenting to the Emergency Department without chest pain. METHODS: During a 6-month period, we routinely measured cTnI in all patients presenting to the internist, neurologist, or lung specialist for reasons other than chest pain. We followed patients with an elevated cTnI for 1 year and determined mortality and incidence of non-fatal myocardial infarction, percutaneous coronary intervention (PCI), and coronary artery bypass grafting (CABG). RESULTS: cTnI was elevated in 41 out of 1130 patients (3.6%). Patients with an elevated cTnI were older (78 vs. 62 years) and more often admitted to the hospital (95% vs. 78%) than those with a normal cTnI. Twenty-six patients (63%) with an elevated cTnI died within 1 year. Approximately 50% of these deaths were cardiac-related. Two patients (4.9%) suffered a non-fatal myocardial infarction, while no patient underwent PCI or CABG during follow-up. CONCLUSION: Routinely measured cTnI is seldom elevated in a general population of patients presenting to the Emergency Department without chest pain. Patients with an elevated cTnI are, on the average, 16 years older than those with a normal level. An elevated cTnI is clearly associated with an unfavorable outcome.

Journal Article↗
PubMed2005

[Severe bleeding in a patient with anti-c alloantibodies and a rare Rhesus phenotype treated with compatible erythrocyte concentrate from the blood bank of the Council of Europe].

An 84-year-old women had repeated gastrointestinal bleeding from a Dieulafoy lesion, i.e. a gastric or duodenal ulcer containing an aberrant artery. Her blood group was AB-D negative; her Rhesus phenotype was CCdee. In addition, antibody screening revealed anti-c alloantibodies as the result of a previous transfusion. Donors negative for D and c are very rare in Caucasian populations. Compatible red cell concentrates are available only from the European Bank of Frozen Blood of the Council of Europe, located at Sanquin in Amsterdam, Tthe Netherlands. The patient could be saved by requesting compatible erythrocyte concentrate from this blood bank. Severe blood loss poses a serious challenge in patients who are positive for alloantibodies against blood group antigens with a high frequency in the population, and in patients who are themselves negative for such antigens. The presence of alloantibodies is often the result of previous blood transfusions. In view of the large number of antigens on erythrocytes, one should therefore be conservative as to blood transfusion in order to prevent alloantibody formation.

Aged, 80 and over↗
PubMed2002

Biofeedback vs verbal feedback as learning tools for pelvic muscle exercises in the early management of urinary incontinence after radical prostatectomy.

OBJECTIVE: To evaluate the comparative effectiveness of electromyographic (EMG) biofeedback with verbal instructions as learning tools of pelvic muscle exercises (PMEs) in the early management of urinary incontinence after radical prostatectomy. PATIENTS AND METHODS: Forty-two consecutive patients (mean age 64 years, sd 4.2), with urinary incontinence after radical retropubic prostatectomy for localized prostate cancer, were randomized to receive biofeedback (group A, 28 men) or verbal feedback (group B, 14 men) as learning tools for PMEs immediately after catheter removal. Group A received 15 sessions of EMG biofeedback (three times weekly, 30 min each) and group B verbal instructions. Evaluation at baseline and 1, 2, 3 and 6 months included the 1-h pad-test and a questionnaire (number of pads/day and incontinence episodes). RESULTS: By the last follow-up, 27 patients had received biofeedback and 15 verbal instructions. Data were analysed according to the intention-to-treat principle. Urine loss as assessed by the 1-h pad-test at baseline, 1, 2, 3 and 6 months was 39, 18, 7, 4 and 3 g for group A and 31, 11, 3, 1 and 0 g for group B, respectively (P > 0.05). The number of pads/day was 3.9, 3.4, 1.2, 0.8 and 0.4 for group A and 3.6, 1.8, 0.9, 0.4 and 0.2 for group B, respectively (P > 0.05). The overall continence rate at 6 months was objectively (urine loss > 1 g) 91% and subjectively (0-1 pad/day) 95%. CONCLUSION: Intensive verbal instructions and biofeedback were both very effective behavioural methods and learning tools for PMEs in the early management of urinary incontinence after radical prostatectomy.

Biofeedback, Psychology↗
PubMed2001

[Roaming through methodology: XXIX. P].

The abundant use of p-values and statistical significance in medical literature often leads to invalid conclusions about the reported study results. A statistically significant result may be clinically irrelevant, while a clinically relevant effect may be ignored due to lack of statistical significance. These false conclusions can be attributed to the fact that p-values are often considered as a measure of relevance, validity and precision of a study outcome. A p-value, however, only conveys information about precision. In addition, a more informative means to describe the precision of a study exists, viz. confidence intervals. It is therefore important that both the editors of medical journals and the authors of scientific papers continue to use confidence intervals instead of p-values.

Confidence Intervals↗
PubMed2001

alpha-Blockade improves symptoms suggestive of bladder outlet obstruction but fails to relieve it.

PURPOSE: We investigated the effect of the alpha-blockers alfuzosin, terazosin and tamsulosin on urodynamic parameters after 6 months of therapy. MATERIALS AND METHODS: Between February 1992 and June 1998, 163 patients with lower urinary tract symptoms suggestive of bladder outlet obstruction were treated with alfuzosin (60), terazosin (66) and tamsulosin (37). Patients were evaluated with urodynamic studies, including pressure flow analysis, before treatment and after 6 months of therapy. Initially, all patients were also assessed by the International Prostate Symptom Score questionnaire and measurement of urinary flow rate. RESULTS: The majority of patients had no clear improvement in obstructive parameters, regardless of the alpha-blocker used, as urethral resistance factor and detrusor pressure maximum flow rate decreased by only 4 cm. H2O. There was a clear subjective and statistically significant decrease in International Prostate Symptom Score and quality of life scores of 6 and 2 points, respectively. No relevant statistical difference was noted among the effects of the 3 alpha-blockers on relieving symptoms or improving urodynamic parameters of obstruction. CONCLUSIONS: The alpha-blockers are effective for treating symptoms suggestive of bladder outlet obstruction in patients presenting with lower urinary tract symptoms but not for treating the obstruction.

Adrenergic alpha-Antagonists↗
PubMed2000

[Prevalence of lower urinary tract symptoms in men and its influence on their quality of life: Boxmeer Study].

OBJECTIVE: To assess the prevalence of lower urinary tract symptoms (LUTS) in men and its influence on quality of life. DESIGN: Questionnaire investigation. METHODS: Recruitment of subjects was conducted in 1998 in the municipality of Boxmeer. Men in the age range between 40-79 years were sampled from the Municipality Basic Administration System. Data on LUTS, quality of life, and health care seeking behaviour were collected with a postal questionnaire. Severity of LUTS was evaluated with the Dutch translation of the seven items of the International Prostate Symptom Score (IPSS), to which 6 questions were added regarding micturition frequency, dribbling, difficulty to start micturition, painful micturition, decreased force of stream since the age of twenty, and how long one could wait before micturition from the moment urge was noticed. The female partners of the respondents were asked to answer the questions as well. RESULTS: 1233 men completed the questionnaire, a response of 70%. One-fifth of all participants reported moderate to severe symptoms. Dribbling, reduced force of stream and urgency appeared to be the three most prevalent symptoms. The prevalence of LUTS increased with age: 10% of men aged 40-49 reported moderate to severe symptoms (IPSS > 7) compared with 44% of men over 70. Twenty-nine per cent of the men with severe LUTS reported poor disease specific quality of life, while another 28% of these men reported excellent disease specific quality of life. All men with mild symptoms reported excellent quality of life. Nine percent of all men consulted a doctor because of LUTS, with a mean delay of 10 months. The LUTS frequencies among the female partners equalled those among the responding men. CONCLUSION: LUTS were common among men over forty and among their female partners. The prevalence increases with age. Ageing of the population may lead to increased numbers of men experiencing LUTS and to concomittant medicalization costs. It is therefore of great importance to realise that the impact of symptoms on the reported quality of life was not pronounced.

Adult↗
PubMed2000

Long-term follow-up of laser treatment for lower urinary tract symptoms suggestive of bladder outlet obstruction.

OBJECTIVES: The long-term results of different laser technologies in the management of lower urinary tract symptoms (LUTS) suggestive of bladder outlet obstruction (BOO) are not well known. We studied the durability of the effect of laser prostatectomy and tried to identify the factors predictive of treatment outcome. METHODS: Between December 1992 and November 1996, 190 patients underwent laser prostatectomy because of LUTS suggestive of BOO. One hundred seven patients received visual laser ablation of the prostate (VLAP), 30 received contact laser vaporization (CLV), and 53 received interstitial laser coagulation (ILC). The baseline evaluation included the International Prostate Symptom Score (IPSS), uroflowmetry (maximum urinary flow rate), postvoid residual urine (PVR), prostate volume measurement, and urodynamic investigation. Patients were followed up until April 1999. Kaplan-Meier plots were constructed to calculate the risk of retreatment, and the log-rank test was used to evaluate the predictive value of clinical parameters for treatment failure. RESULTS: The median follow-up in the VLAP group was 53 months; the retreatment rate was 14% (95% confidence interval [CI] 6% to 22%). The corresponding numbers for the CLV and ILC groups were 47 months and 14% (95% CI 1% to 26%) and 34 months and 41% (95% CI 23% to 60%), respectively. A high PVR and a high grade of obstruction in the VLAP group, and a younger age in the ILC group, were associated with increased retreatment risk. CONCLUSIONS: VLAP and CLV have a durable effect, as demonstrated by their low retreatment rate. ILC is a less aggressive procedure, at the expense of a high retreatment rate. Patient selection for VLAP can be based on the grade of obstruction and PVR.

Case-Control Studies↗
PubMed2000

Intra- and inter-investigator variation in the analysis of pressure-flow studies in men with lower urinary tract symptoms.

The objective of this study was to assess the intra- and inter-investigator variation in the analysis of pressure-flow studies that were performed in men with lower urinary tract symptoms. Two hospitals were involved in this study. In each hospital 100 PFS were selected. Photocopies of printouts of all PFS were analyzed manually by six experienced investigators, including determination of P(detQmax) and Q(max). Afterward, all 200 PFS were analyzed again in a different order. For each P(detQmax) and accompanying Q(max) the AG-number was calculated. With these AG numbers, the intra-investigator SD, the inter-investigator SD and the intra- and inter-investigator SD combined were calculated. The intra- and inter-investigator SD combined was 10.7. This implies that if one investigator analyzes a PFS once and determines an AG number of 40, another investigator may determine an AG number between 40 +/- 2. 77*10.7 = 10-70, using a 95% confidence interval. The inter-investigator SD was 10.0 and the intra-investigator SD was 3.7. The reproducibility of the manual analysis of urodynamic studies is moderate owing to a considerable intra- and inter- investigator variation. This is mostly caused by the substantial intra-investigator variation.

Humans↗
PubMed2000

Variability of pressure-flow studies in men with lower urinary tract symptoms.

The objective of this study was to assess the short-term test-retest variability of pressure-flow studies (PFS) in men with lower urinary tract symptoms (LUTS). By choosing a short interval between two consecutive PFS, but notably not performing two tests within a single session, both tests represent the same routine testing procedure. Eighty-nine patients with LUTS suggestive of bladder outlet obstruction or detrusor underactivity, who received PFS, were asked to undergo a second urodynamic evaluation within 4 weeks after the initial test. At both visits, specialized physicians performed the PFS. Obstruction was quantified using the Abrams-Griffiths number (AG number). Each patient was classified as obstructed, unobstructed, or equivocally obstructed according to the International Continence Society nomogram. As expected, no systematic difference was observed in AG number between the first and the second visit at the group level. There was, however, considerable variation at the individual level. The average within-patient standard deviation was 14 cm H(2)O. This finding shows that if a patient's AG number is 30 at the first visit, his true AG number can be any value between 30 +/- 1.96 * 14 = 3 to 57, owing to random variability alone. The average within-patient standard deviation did not differ significantly between sub-groups of obstruction and other variables such as patient age, symptom score, prostate volume, or residual volume. The variability appeared to increase slightly with an increased interval between visits. Of all patients, 39% changed at least one category of obstruction at the second visit and 3% changed from definitely obstructed to definitely unobstructed or vice versa. We conclude that PFS cannot stand the test of serving as a gold standard to identify bladder outlet obstruction in patients with LUTS.

Aged↗
PubMed2000

Prediction of bladder outlet obstruction in men with lower urinary tract symptoms using artificial neural networks.

PURPOSE: To evaluate the performance of a backpropagation artificial neural network (ANN) in the diagnosis of men with lower urinary tract symptoms (LUTS) and to compare its performance to that of a traditional linear regression model. MATERIALS AND METHODS: 1903 LUTS patients referred to the University Hospital Nijmegen between 1992 and 1998 received routine investigation, consisting of transrectal ultrasonography of the prostate, serum PSA measurement, assessment of symptoms and quality of life by the International Prostate Symptom Score (IPSS), urinary flowmetry with determination of maximum flow rate (Qmax), voided volume and post-void residual urine and full pressure flow studies (PFS). Using a three-layered backpropagation ANN with three hidden nodes, the outcome of PFS, quantified by the Abrams-Griffiths number (AG-number), was estimated based on all available non-invasive diagnostic test results plus patient age. The performance of the network was quantified using sensitivity, specificity and the area under the ROC-curve (AUC). The results of the neural network approach were compared to those of a linear regression analysis. RESULTS: Prostate volume, Qmax, voided volume and post void residual urine showed substantial predictive value concerning the outcome of PFS. Patient age, PSA-level, IPSS and Quality of life did not add to that prediction. Using a cut-off value in predicted and true AG-numbers of 40 cm. H2O, the neural network approach yielded sensitivity and specificity of 71% and 69%, respectively. The AUC of the network was 0.75 (standard error = 0.01). A linear regression model produced identical results. CONCLUSIONS: This study shows that at an individual level, the outcome of PFS cannot be predicted accurately by the available non-invasive tests. The use of ANNs, which are better able than traditional regression models to identify non-linear relations and complex interactions between variables, did not improve the prediction of BOO. Thus, if precise urodynamic information is considered important in the diagnosis of men with LUTS, PFS must be carried out. Both neural networks and regression analysis appear promising to identify patients who should undergo PFS, and those in whom PFS can safely be omitted. Furthermore, the ability of ANNs and regression models to predict treatment result should be evaluated.

Humans↗
PubMed2000

High energy transurethral microwave thermotherapy for the treatment of patients in urinary retention.

PURPOSE: We evaluated the efficacy of high energy transurethral microwave thermotherapy for treating urinary retention due to benign prostatic hyperplasia. MATERIALS AND METHODS: Between October 1993 and March 1999, 41 patients with urinary retention were treated with high energy transurethral microwave thermotherapy. Initial evaluation consisted of a history, clinical examination, urethrocystoscopy, transrectal prostate ultrasonography and urodynamic investigation with a pressure flow study. Followup visits at 12, 26 and 52 weeks included International Prostate Symptom Score (I-PSS), uroflowmetry and post-void residual urine volume determination. At 26 weeks the urodynamic study was repeated. Kaplan-Meier plots were constructed to evaluate the risk of re-treatment adjusted for patients lost to followup. RESULTS: At baseline median patient age was 74 years and median prostate size was 67 ml. Median 133 kJ. were administered. Nine patients underwent re-treatment and 11 were lost to followup. The re-treatment rate after 1 year was 25% (95% confidence interval 11 to 40). In good responders at 12, 26 and 52 weeks median maximal urine free flow was 15, 11 and 15 ml. per second, post-void residual urine volume was 61, 8 and 35 ml., and I-PSS was 7, 5 and 2, respectively. Quality of life (I-PSS question 8) was 1 at all visits. CONCLUSIONS: In patients with severe co-morbidity transurethral microwave thermotherapy is often the only alternative to an indwelling catheter with obvious quality of life advantages. High energy transurethral microwave thermotherapy appears to be effective in these patients.

Aged↗
PubMed1999

Low reproducibility of maximum urinary flow rate determined by portable flowmetry.

To evaluate the reproducibility in maximum urinary flow rate (Qmax) in men with lower urinary tract symptoms (LUTSs) and to determine the number of flows needed to obtain a specified reliability in mean Qmax, 212 patients with LUTSs (mean age, 62 years) referred to the University Hospital Nijmegen, with various degrees of obstruction on pressure-flow studies, used a portable home-based uroflowmeter with 12 disposable beakers. Voided volume and maximum flow rate were recorded continuously during micturition. Flows with voided volumes of at least 100 ml and without possible artifacts were included. All analyses were repeated while excluding flows with voided volumes <150 ml. A coefficient of variation (CV) was calculated for each patient. The CV represents the standard deviation relative to the mean. All individual CVs were subsequently pooled into a population mean CV. This parameter was used to estimate the number of flows required to obtain a mean Qmax with specified reliability for an individual patient. All analyses were repeated, while successively excluding the first, the first two, and the first three flows, to assess a possible learning curve. A total of 1,854 flows was available for analyses, yielding an average of nine flows per patient. Mean Qmax was 13.2 ml/sec; the mean CV was 24%. To allow, for instance, a 10% deviation from the true mean Qmax (e.g., 15 ml/s +/- 1.5 ml/s), approximately 25 flows are necessary. The actual number of flows needed is in fact even higher due to the presence of small and artifactual flows. Using a 150 ml volume cutoff point, somewhat fewer flows are required, but the total number of flows needed (that is, valid, small, and artifactual flows) increases. There was no evidence of a learning curve. The boundaries of a confidence interval around a single Qmax measurement that is likely to contain the true mean Qmax, lie approximately 50% below or above that single Qmax measurement. To reduce this proportion down to 10%, approximately 25 flows are needed. Thus, to obtain reliable mean Qmax values, considerably more flows are required than are normally performed in urologic practice.

Analysis of Variance↗
PubMed1999

The tolerability of urodynamic studies and flexible cysto-urethroscopy used in the assessment of men with lower urinary tract symptoms.

OBJECTIVE: To determine the overall tolerability of urodynamic studies used in the assessment of men with lower urinary tract symptoms (LUTS), by assessing the objective and subjective morbidity experienced during and after urodynamic studies, and to assess the voiding complaints caused by the combination of urodynamic studies with flexible cysto-urethroscopy. PATIENTS AND METHODS: A total of 103 men with LUTS, who underwent a urodynamic study combined with flexible cysto-urethroscopy, completed a questionnaire designed to assess objective and subjective symptoms and degree of bother, with emphasis on the urodynamic study. In addition, a urine specimen was analysed and cultured. In all, 78 patients who underwent a second urodynamic study completed the questionnaire twice. RESULTS: The results of the first questionnaire showed that more than half of the patients experienced some urge after the urodynamic study and cysto-urethroscopy (56%); 35% of the patients experienced little and 19% experienced severe voiding discomfort after the combined investigations, compared with 24% and 5%, respectively, after a urodynamic study alone. Three patients (3%) had a symptomatic urinary tract infection. Haematuria, increased voiding frequency and increased nocturia occurred occasionally. Most of the patients found the urodynamic study less bothersome than they had expected (64%) and only 9% found it worse than expected. The overall degree of discomfort, experienced during and after the urodynamic study combined with cysto-urethroscopy, was low, and after a second urodynamic study was even lower. CONCLUSION: In contrast with earlier results, this clinic-based urodynamic investigation was associated with a low proportion of urinary tract infection, and low objective and subjective morbidity. The combination of a urodynamic study with a flexible cysto-urethroscopy does not cause significant additional voiding complaints. Most patients find urodynamic studies tolerable and not very bothersome.

Antibiotic Prophylaxis↗
PubMed1999

Diagnostic research in benign prostatic hyperplasia--from sensitivity to neural networks.

Establishing the diagnosis in patients with lower urinary tract symptoms is complicated. Several tests have been developed, but the importance of each of these tests in the diagnostic process is not well understood. This paper describes the methods used to evaluate diagnostic tests, ranging from traditional sensitivity and specificity to more sophisticated techniques such as logistic regression and neural networks.

Animals↗
PubMed1999

Kidney cancer mortality in The Netherlands, 1950-94: prediction of a decreasing trend.

BACKGROUND: Incidence and mortality rates of kidney cancer are known to be increasing world-wide. The reasons for these increases are not clear, but despite this it may still be possible to predict changes in the trend of occurrence. METHODS: Male and female kidney (plus ureter and urethra) cancer mortality per 10(5) person-years, from 1950 to 94, were calculated using national demographic and mortality data. Changes in the age structure of the Dutch population were adjusted using direct standardisation to the European standard population. The effects of age, calendar period and birth cohort on the temporal trend in mortality were evaluated using log-linear modelling. RESULTS: Male mortality from kidney cancer increased from three per 10(5) person-years in the 1950s to eight per 10(5) in the mid 1980s and remained relatively stable thereafter. Female mortality rates showed a comparable trend, from two per 10(5) in the 1950s to four per 10(5) in the 1980s. In addition to the effects of age, the temporal trend in males can be sufficiently explained as a birth cohort effect. Successive birth cohorts appear to have higher risks of dying from kidney cancer until the 1930 cohort. The younger birth cohorts appear to have lower risks. The trend in women is comparable to that in men but is less pronounced and shows only after excluding women under the age of 45. CONCLUSION: The decreasing risk for generations born after 1930 will probably result in a decreasing trend in kidney cancer mortality in the near future. It is suggested that at least part of this changing trend in men (but not in women) is caused by the changing smoking behaviour of the Dutch population.

Adolescent↗
PubMed1996

Sex differences in case fatality before and after admission to hospital after acute cardiac events: analysis of community based coronary heart disease register.

OBJECTIVE: To determine whether the reported higher case fatality in hospital after an acute cardiac event in women can be explained by sex differences in mortality before admission and in baseline risk factors. DESIGN: Analyses of data from a community based coronary heart disease register. SETTING: Auckland region, New Zealand. SUBJECTS: 5106 patients aged 25-64 years with an acute cardiac event leading to coronary death or definite myocardial infarction within 28 days of onset, occurring between 1986 and 1992. MAIN OUTCOME MEASURES: Case fatality before admission, 28 day case fatality for patients in hospital, and total case fatality after an acute cardiac event. RESULTS: Despite a more unfavourable risk profile women tended to have lower case fatality before admission than men (crude odds ratio 0.88; 95% confidence interval 0.77 to 1.02). Adjustment for age, living arrangements, smoking, medical history, and treatment increased the effect of sex (0.72; 0.60 to 0.86). After admission to hospital, women had a higher case fatality than men (1.76; 1.43 to 2.17), but after adjustment for confounders this was reduced to 1.18 (0.89 to 1.58). Total case fatality 28 days after an acute cardiac event showed no significant difference between men and women (0.85; 0.70 to 1.02) CONCLUSIONS: The higher case fatality after an acute cardiac event in women admitted to hospital is largely explained by differences in living status, history, and medical treatment and is balanced by a lower case fatality before admission.

Adult↗