Aspirine wordt door miljoenen mensen wereldwijd gebruikt ter preventie van hart- en vaatziekten. De meeste mensen nemen aspirine 's ochtends in, maar het optimale inname tijdstip is niet bekend. In... Show moreAspirine wordt door miljoenen mensen wereldwijd gebruikt ter preventie van hart- en vaatziekten. De meeste mensen nemen aspirine 's ochtends in, maar het optimale inname tijdstip is niet bekend. In dit proefschrift is onderzocht voordelig is om aspirine 's avonds in te nemen in plaats van 's ochtends. Kort samengevat was het idee hierachter als volgt. Bloeddruk is een belangrijke risicofactor voor hart- en vaatziekten; eerder onderzoek suggereerde dat de bloeddruk kan worden verlaagd door aspirine 's avonds in te nemen in plaats van 's ochtends. Dit was echter nog nooit onderzocht bij pati_nten die al aspirine gebruiken. Bij 290 pati_nten die aspirine gebruikten werd onderzocht of avond aspirine de bloeddruk verlaagt. Dit bleek niet het geval. Verder is bekend dat hart- en vaatziekten vaker 's ochtends voorkomen. Een van de oorzaken is een verhoogde activiteit van bloedplaatjes tijdens de ochtenduren, waardoor het risico op een bloedstolsel (met een hart- of herseninfarct tot gevolg) hoger is tijdens de ochtenduren. Onderzocht werd of de bloedplaatjes activiteit tijdens de ochtenduren beter geremd kan worden door aspirine 's avonds in te nemen in plaats van 's ochtends. Dit bleek inderdaad zo te zijn. Dit is mogelijk voordelig voor alle pati_nten die aspirine gebruiken Show less
Introduction: Guidelines recommend that two blood cultures be performed in patients with febrile urinary tract infection (UTI), to detect bacteremia and help diagnose urosepsis. The usefulness and... Show moreIntroduction: Guidelines recommend that two blood cultures be performed in patients with febrile urinary tract infection (UTI), to detect bacteremia and help diagnose urosepsis. The usefulness and cost-effectiveness of this practice have been criticized. This study aimed to evaluate clinical characteristics and the biomarker procalcitonin (PCT) as an aid in predicting bacteremia. Methods: A prospective observational multicenter cohort study included consecutive adults with febrile UTI in 35 primary care units and 8 emergency departments of 7 regional hospitals. Clinical and microbiological data were collected and PCT and time to positivity (TTP) of blood culture were measured. Results: Of 581 evaluable patients, 136 (23%) had bacteremia. The median age was 66 years (interquartile range 46 to 78 years) and 219 (38%) were male. We evaluated three different models: a clinical model including seven bedside characteristics, the clinical model plus PCT, and a PCT only model. The diagnostic abilities of these models as reflected by area under the curve of the receiver operating characteristic were 0.71 (95% confidence interval (CI): 0.66 to 0.76), 0.79 (95% CI: 0.75 to 0.83) and 0.73 (95% CI: 0.68 to 0.77) respectively. Calculating corresponding sensitivity and specificity for the presence of bacteremia after each step of adding a significant predictor in the model yielded that the PCT > 0.25 mu g/l only model had the best diagnostic performance (sensitivity 0.95; 95% CI: 0.89 to 0.98, specificity 0.50; 95% CI: 0.46 to 0.55). Using PCT as a single decision tool, this would result in 40% fewer blood cultures being taken, while still identifying 94 to 99% of patients with bacteremia. The TTP of E. coli positive blood cultures was linearly correlated with the PCT log value; the higher the PCT the shorter the TTP (R-2 = 0.278, P = 0.007). Conclusions: PCT accurately predicts the presence of bacteremia and bacterial load in patients with febrile UTI. This may be a helpful biomarker to limit use of blood culture resources. Show less
Nieuwkoop, C. van; Bonten, T.N.; van't Wout, J.W.; Kuijper, E.J.; Groeneveld, G.H.; Becker, M.J.; ... ; Dissel, J.T. van 2010
INTRODUCTION Guidelines recommend that two blood cultures be performed in patients with febrile urinary tract infection (UTI), to detect bacteremia and help diagnose urosepsis. The usefulness and... Show moreINTRODUCTION Guidelines recommend that two blood cultures be performed in patients with febrile urinary tract infection (UTI), to detect bacteremia and help diagnose urosepsis. The usefulness and cost-effectiveness of this practice have been criticized. This study aimed to evaluate clinical characteristics and the biomarker procalcitonin (PCT) as an aid in predicting bacteremia. METHODS A prospective observational multicenter cohort study included consecutive adults with febrile UTI in 35 primary care units and 8 emergency departments of 7 regional hospitals. Clinical and microbiological data were collected and PCT and time to positivity (TTP) of blood culture were measured. RESULTS Of 581 evaluable patients, 136 (23%) had bacteremia. The median age was 66 years (interquartile range 46 to 78 years) and 219 (38%) were male. We evaluated three different models: a clinical model including seven bed-side characteristics, the clinical model plus PCT, and a PCT only model. The diagnostic abilities of these models as reflected by area under the curve of the receiver operating characteristic were 0.71 (95% confidence interval (CI): 0.66 to 0.76), 0.79 (95% CI: 0.75 to 0.83) and 0.73 (95% CI: 0.68 to 0.77) respectively. Calculating corresponding sensitivity and specificity for the presence of bacteremia after each step of adding a significant predictor in the model yielded that the PCT > 0.25 μg/l only model had the best diagnostic performance (sensitivity 0.95; 95% CI: 0.89 to 0.98, specificity 0.50; 95% CI: 0.46 to 0.55). Using PCT as a single decision tool, this would result in 40% fewer blood cultures being taken, while still identifying 94 to 99% of patients with bacteremia.The TTP of E. coli positive blood cultures was linearly correlated with the PCT log value; the higher the PCT the shorter the TTP (R(2) = 0.278, P = 0.007). CONCLUSIONS PCT accurately predicts the presence of bacteremia and bacterial load in patients with febrile UTI. This may be a helpful biomarker to limit use of blood culture resources. Show less
Nieuwkoop, C. van; Hoppe, B.P.C.; Bonten, T.N.; van't Wout, J.W.; Aarts, N.J.M.; Mertens, B.J.; ... ; Dissel, J.T. van 2010
Background. Radiologic evaluation of adults with febrile urinary tract infection (UTI) is frequently performed to exclude urological disorders. This study aims to develop a clinical rule predicting... Show moreBackground. Radiologic evaluation of adults with febrile urinary tract infection (UTI) is frequently performed to exclude urological disorders. This study aims to develop a clinical rule predicting need for radiologic imaging. Methods. We conducted a prospective, observational study including consecutive adults with febrile UTI at 8 emergency departments (EDs) in the Netherlands. Outcomes of ultrasounds and computed tomographs of the urinary tract were classified as "urgent urological disorder" (pyonephrosis or abscess), "nonurgent urologic disorder," "normal," and "incidental nonurological findings." Urgent and nonurgent urologic disorders were classified as " clinically relevant radiologic findings." The data of 5 EDs were used as the derivation cohort, and 3 EDs served as the validation cohort. Results. Three hundred forty-six patients were included in the derivation cohort. Radiologic imaging was performed for 245 patients (71%). A prediction rule was derived, being the presence of a history of urolithiasis, a urine pH >= 7.0, and/or renal insufficiency (estimated glomerular filtration rate, <= 40 mL/min/1.73 m(3)). This rule predicts clinically relevant radiologic findings with a negative predictive value (NPV) of 93% and positive predictive value (PPV) of 24% and urgent urological disorders with an NPV of 99% and a PPV of 10%. In the validation cohort (n = 131), the NPV and PPV for clinically relevant radiologic findings were 89% and 20%, respectively; for urgent urological disorders, the values were 100% and 11%, respectively. Potential reduction of radiologic imaging by implementing the prediction rule was 40%. Conclusions. Radiologic imaging can selectively be applied in adults with febrile UTI without loss of clinically relevant information by using a simple clinical prediction rule. Show less
Nieuwkoop, C. van; Bonten, T.N.; van't Wout, J.W.; Becker, M.J.; Groeneveld, G.H.; Jansen, C.L.; ... ; Dissel, J.T. van 2010
In a prospective study involving 642 patients with febrile urinary tract infection (UTI), we found antimicrobial pretreatment (odds ratio [OR], 3.3), an indwelling urinary catheter (OR, 2.8), and... Show moreIn a prospective study involving 642 patients with febrile urinary tract infection (UTI), we found antimicrobial pretreatment (odds ratio [OR], 3.3), an indwelling urinary catheter (OR, 2.8), and malignancy (OR, 2.7) to be independent risk factors for bacteremia with a uropathogen that was not cultured or recognized in the urine. Although the diagnostic value of blood cultures has been questioned in UTI, we advocate performing blood cultures for patients with these risk factors. Show less
Nieuwkoop, C. van; Bonten, T.N.; van't Wout, J.W.; Becker, M.J.; Groeneveld, G.H.; Jansen, C.L.; ... ; Dissel, J.T. van 2010
