Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Johanna C. Korevaar is active.

Publication


Featured researches published by Johanna C. Korevaar.


Critical Care | 2010

Ventilation with lower tidal volumes as compared with conventional tidal volumes for patients without acute lung injury: a preventive randomized controlled trial

Rogier M. Determann; Annick A. N. M. Royakkers; Esther K. Wolthuis; Alexander P. J. Vlaar; Goda Choi; Frederique Paulus; Jorrit-Jan H Hofstra; Mart J de Graaff; Johanna C. Korevaar; Marcus J. Schultz

IntroductionRecent cohort studies have identified the use of large tidal volumes as a major risk factor for development of lung injury in mechanically ventilated patients without acute lung injury (ALI). We compared the effect of conventional with lower tidal volumes on pulmonary inflammation and development of lung injury in critically ill patients without ALI at the onset of mechanical ventilation.MethodsWe performed a randomized controlled nonblinded preventive trial comparing mechanical ventilation with tidal volumes of 10 ml versus 6 ml per kilogram of predicted body weight in critically ill patients without ALI at the onset of mechanical ventilation. The primary end point was cytokine levels in bronchoalveolar lavage fluid and plasma during mechanical ventilation. The secondary end point was the development of lung injury, as determined by consensus criteria for ALI, duration of mechanical ventilation, and mortality.ResultsOne hundred fifty patients (74 conventional versus 76 lower tidal volume) were enrolled and analyzed. No differences were observed in lavage fluid cytokine levels at baseline between the randomization groups. Plasma interleukin-6 (IL-6) levels decreased significantly more strongly in the lower-tidal-volume group ((from 51 (20 to 182) ng/ml to 11 (5 to 20) ng/ml versus 50 (21 to 122) ng/ml to 21 (20 to 77) ng/ml; P = 0.01)). The trial was stopped prematurely for safety reasons because the development of lung injury was higher in the conventional tidal-volume group as compared with the lower tidal-volume group (13.5% versus 2.6%; P = 0.01). Univariate analysis showed statistical relations between baseline lung-injury score, randomization group, level of positive end-expiratory pressure (PEEP), the number of transfused blood products, the presence of a risk factor for ALI, and baseline IL-6 lavage fluid levels and the development of lung injury. Multivariate analysis revealed the randomization group and the level of PEEP as independent predictors of the development of lung injury.ConclusionsMechanical ventilation with conventional tidal volumes is associated with sustained cytokine production, as measured in plasma. Our data suggest that mechanical ventilation with conventional tidal volumes contributes to the development of lung injury in patients without ALI at the onset of mechanical ventilation.Trial registrationISRCTN82533884


Journal of The American Society of Nephrology | 2004

Relative Contribution of Residual Renal Function and Different Measures of Adequacy to Survival in Hemodialysis Patients: An analysis of the Netherlands Cooperative Study on the Adequacy of Dialysis (NECOSAD)-2

Fabian Termorshuizen; Friedo W. Dekker; Jeannette G. van Manen; Johanna C. Korevaar; Elisabeth W. Boeschoten; Raymond T. Krediet

A high delivered Kt/V(urea) (dKt/V(urea)) is advocated in the U.S. National Kidney Foundation Dialysis Outcomes Quality Initiative guidelines on hemodialysis (HD) adequacy, irrespective of the presence of residual renal function. The contribution of treatment adequacy and residual renal function to patient survival was investigated. The Netherlands Cooperative Study on the Adequacy of Dialysis is a prospective multicenter study that includes incident ESRD patients older than 18 yr. The longitudinal data on residual renal function and dialysis adequacy of patients who were treated with HD 3 mo after the initiation of dialysis (n = 740) were analyzed. The mean renal Kt/V(urea) (rKt/V(urea)) at 3 mo was 0.7/wk (SD 0.6) and the dKt/V(urea) at 3 mo was 2.7/wk (SD 0.8). Both components of urea clearance were associated with a better survival (for each increase of 1/wk in rKt/V(urea), relative risk of death = 0.44 [P < 0.0001]; dKt/V(urea), relative risk of death = 0.76 [P < 0.01]). However, the effect of dKt/V(urea) on mortality was strongly dependent on the presence of rKt/V(urea), low values for dKt/V(urea) of <2.9/wk being associated with a significantly higher mortality in anuric patients only. Furthermore, an excess of ultrafiltration in relation to interdialytic weight gain was associated with an increase in mortality independent of dKt/V(urea). In conclusion, residual renal clearance seems to be an important predictor of survival in HD patients, and the dKt/V(urea) should be tuned appropriately to the presence of renal function. Further studies are required to substantiate the important role of fluid balance in HD adequacy.


BMJ | 2006

Effect of clomifene citrate plus metformin and clomifene citrate plus placebo on induction of ovulation in women with newly diagnosed polycystic ovary syndrome: randomised double blind clinical trial

Etelka Moll; Patrick M. Bossuyt; Johanna C. Korevaar; Cornelis B. Lambalk; Fulco van der Veen

Abstract Objective To compare the effectiveness of clomifene citrate plus metformin and clomifene citrate plus placebo in women with newly diagnosed polycystic ovary syndrome. Design Randomised clinical trial. Setting Multicentre trial in 20 Dutch hospitals. Participants 228 women with polycystic ovary syndrome. Interventions Clomifene citrate plus metformin or clomifene citrate plus placebo. Main outcome measure The primary outcome measure was ovulation. Secondary outcome measures were ongoing pregnancy, spontaneous abortion, and clomifene resistance. Results 111 women were allocated to clomifene citrate plus metformin (metformin group) and 114 women were allocated to clomifene citrate plus placebo (placebo group). The ovulation rate in the metformin group was 64% compared with 72% in the placebo group, a non-significant difference (risk difference − 8%, 95% confidence interval − 20% to 4%). There were no significant differences in either rate of ongoing pregnancy (40% v 46%; − 6%, − 20% to 7%) or rate of spontaneous abortion (12% v 11%; 1%, − 7% to 10%). A significantly larger proportion of women in the metformin group discontinued treatment because of side effects (16% v 5%; 11%, 5% to 16%). Conclusion Metformin is not an effective addition to clomifene citrate as the primary method of inducing ovulation in women with polycystic ovary syndrome. Trial registration Current Controlled Trials ISRCTN55906981 [controlled-trials.com][controlled-trials.com].


American Journal of Kidney Diseases | 2003

The relative importance of residual renal function compared with peritoneal clearance for patient survival and quality of life: an analysis of the netherlands cooperative study on the adequacy of dialysis (Necosad)-2

Fabian Termorshuizen; Johanna C. Korevaar; Friedo W. Dekker; Jeannette G. van Manen; Elisabeth W. Boeschoten; Raymond T. Krediet

BACKGROUND The guidelines from the US National Kidney Foundation Dialysis Outcomes Quality Initiative on peritoneal dialysis (PD) assume equivalence between the peritoneal and the renal solute clearance. The authors examined in a prospective cohort study of incident dialysis patients the relative contribution of residual renal function and peritoneal clearance to patient survival and quality of life (QoL). METHODS The authors analyzed the longitudinal data on residual renal function, clearance by dialysis, and QoL of those patients who were treated with PD 3 months after the start of dialysis and participated in a prospective multicenter study in the Netherlands (n = 413). RESULTS The mean age was 52 years, the mean residual glomerular filtration rate (rGFR) at 3 months was 4.1 mL/min/1.73 m2 (SD: 2.7), and the mean peritoneal creatinine clearance (pCrCl) at 3 months was 4.1 mL/min/1.73 m2 (SD: 1.1). The 2-year survival was 84%. For each mL/min/1.73 m2 increase in rGFR, a 12% reduction in mortality rate was found (relative risk of death [RR] = 0.88, P = 0.039). In contrast, no significant effect of pCrCl on patient survival was established (RR = 0.91, P = 0.47). The differential impact of rGFR and pCrCl was confirmed in an analysis on combined patient and technique survival and in an analysis on a number of generic and disease-specific dimensions of QoL. CONCLUSION The beneficial effect of renal clearance and the absence of an effect of peritoneal clearance in the range of values common in current practice on patient outcome indicate that the 2 components of total solute clearance should not be regarded as equivalent. Higher peritoneal clearance targets do not necessarily improve patient outcome.


Blood | 2011

The incidence, risk factors and outcome of transfusion-related acute lung injury in a cohort of cardiac surgery patients: a prospective nested case control study

Alexander P. J. Vlaar; Jorrit J. Hofstra; Rogier M. Determann; Denise P. Veelo; Frederique Paulus; Wim Kulik; Johanna C. Korevaar; Bas A. de Mol; Marianne M. W. Koopman; Leendert Porcelijn; Jan M. Binnekade; Margreeth B. Vroom; Marcus J. Schultz; Nicole P. Juffermans

Transfusion-related acute lung injury (TRALI) is the leading cause of transfusion-related morbidity and mortality. Both antibodies and bioactive lipids that have accumulated during storage of blood have been implicated in TRALI pathogenesis. In a single-center, nested, case-control study, patients were prospectively observed for onset of TRALI according to the consensus definition. Of 668 patients, 16 patients (2.4%) developed TRALI. Patient-related risk factors for onset of TRALI were age and time on the cardiopulmonary bypass. Transfusion-related risk factors were total amount of blood products (odds ratio [OR] = 1.2; 95% confidence interval [CI], 1.03-1.44), number of red blood cells stored more than 14 days (OR = 1.6; 95% CI, 1.04-2.37), total amount of plasma (OR = 1.2; 95% CI, 1.03-1.44), presence of antibodies in donor plasma (OR = 8.8; 95% CI, 1.8-44), and total amount of transfused bioactive lipids (OR = 1.0; 95% CI, 1.00-1.07). When adjusted for patient risk factors, only the presence of antibodies in the associated blood products remained a risk factor for TRALI (OR = 14.2; 95% CI, 1.5-132). In-hospital mortality of TRALI was 13% compared with 0% and 3% in transfused and nontransfused patients, respectively (P < .05). In conclusion, the incidence of TRALI is high in cardiac surgery patients and associated with adverse outcome. Our results suggest that cardiac surgery patients may benefit from exclusion of blood products containing HLA/HNA antibodies.


Quality of Life Research | 2002

Validation of the KDQOL-SFTM: A dialysis-targeted health measure

Johanna C. Korevaar; Maruschka P. Merkus; Maarten Jansen; Friedo W. Dekker; Els W. Boeschoten; Raymond T. Krediet

Background: In evaluations of dialysis therapy, an assessment of health-related quality of life (HRQOL) is often important. The aim of this study was to determine the basic psychometric properties, reliability and validity of the short form of the KDQOLTM i.e. the KDQOL-SFTM, a dialysis-targeted instrument, and to assess its ability to detect changes over time. Methods: In a prospective cohort study (Netherlands Cooperative Study on the Adequacy of Dialysis, NECOSAD), all new adult ESRD patients in 32 different Dutch centers were consecutively enrolled. Demographic, clinical and HRQOL data were obtained 3 and 12 months after the start of chronic dialysis therapy. Results: The reliability of the KDQOL-SFTM was supported by test results that were above the recommended minimal values. Validity of KDQOL-SFTM was confirmed by the hypothesized positive correlations of the overall health rating and renal function, and by the negative correlations between the number of comorbidities and dialysis dose. Moreover, dialysis-targeted dimensions were more sensitive in detecting relevant differences pertaining to kidney diseases than generic dimensions. The KDQOL-SFTM was able to detect clinical changes over time. Conclusions: The psychometric properties of the KDQOL-SFTM were good, and the different dialysis-targeted dimensions were informative with a high reliability and validity. These results support the application of the KDQOL-SFTM in studies evaluating dialysis therapy.


Human Reproduction Update | 2011

Chromosomal mosaicism in human preimplantation embryos: a systematic review

Jannie van Echten-Arends; Sebastiaan Mastenbroek; Birgit Sikkema-Raddatz; Johanna C. Korevaar; Maas Jan Heineman; Fulco van der Veen; Sjoerd Repping

BACKGROUND Although chromosomal mosaicism in human preimplantation embryos has been described for almost two decades, its exact prevalence is still unknown. The prevalence of mosaicism is important in the context of preimplantation genetic screening in which the chromosomal status of an embryo is determined by the analysis of a single cell from that embryo. METHODS Here we report a systematic review and meta-analysis of studies on the chromosomal constitution of human preimplantation embryos. In 36 studies, out of 2117 citations that met our search criteria, data were provided extensively enough to allow classification of each analysed embryo with prespecified criteria for its chromosomal makeup. The main outcome of this classification was the prevalence of chromosomal mosaicism in human preimplantation embryos. RESULTS A total of 815 embryos could be classified. Of these, 177 (22%) were diploid, 599 (73%) were mosaic, of which 480 (59% of the total number of embryos) were diploid-aneuploid mosaic and 119 (14% of the total number of embryos) were aneuploid mosaic, and 39 (5%) contained other numerical chromosomal abnormalities. The distribution of the embryos over these categories was associated with the developmental stage of the embryos, the method used for analysis and the number of chromosomes analysed. CONCLUSIONS Diploid-aneuploid mosaicism is by far the most common chromosomal constitution in spare human preimplantation embryos after IVF. This undermines the reliable determination of the ploidy status of a cleavage-stage embryo based on the analysis of a single cell. Future research should determine the origin and developmental potential of mosaic embryos.


Journal of the American Geriatrics Society | 2008

Time-course of cytokines during delirium in elderly patients with hip fractures

Barbara C. van Munster; Johanna C. Korevaar; Aeilko H. Zwinderman; Marcel Levi; W. Joost Wiersinga; Sophia E. de Rooij

OBJECTIVES: To compare the time‐course of cytokine levels in patients with and without delirium and investigate differences in cytokine concentrations in delirium subtypes.


Journal of the American Geriatrics Society | 2008

Cognitive, Functional, and Quality‐of‐Life Outcomes of Patients Aged 80 and Older Who Survived at Least 1 Year After Planned or Unplanned Surgery or Medical Intensive Care Treatment

Sophia E. de Rooij; Annerike C. Govers; Johanna C. Korevaar; Arja W. Giesbers; Marcel Levi; Evert de Jonge

OBJECTIVES: To investigate long‐term cognitive, functional, and quality‐of‐life outcomes in very elderly survivors at least 1 year after planned or unplanned surgery or medical intensive care treatment.


Nephrology Dialysis Transplantation | 2011

Progression of aortic calcification is associated with disorders of mineral metabolism and mortality in chronic dialysis patients

Marlies Noordzij; Ellen C. M. Cranenburg; Lyda F. Engelsman; Marc M.H. Hermans; Elisabeth W. Boeschoten; Vincent Brandenburg; Willem Jan W. Bos; Jeroen P. Kooman; Friedo W. Dekker; Markus Ketteler; Leon J. Schurgers; Raymond T. Krediet; Johanna C. Korevaar

BACKGROUND Previous studies have shown that simple imaging methods may be useful for detection of vascular calcifications in dialysis patients. Based on annual, plain chest X-rays during follow-up on dialysis, we studied the associations of mineral metabolism with the presence and progression of aortic calcification. In addition, we assessed the impact of aortic calcification on mortality. METHODS Three hundred and eighty-four patients who started haemodialysis or peritoneal dialysis between 1997 and 2007 were included (age 61 ± 15 years, 64% male, 61% haemodialysis). Annual chest X-rays were screened for calcification in the aortic arch, and patients were categorized as having no, moderate or severe calcification. Progression was defined as an increase in calcification category during follow-up on dialysis. RESULTS At baseline, 96 (25%) patients had severe, 205 (53%) patients had moderate and 83 (22%) patients had no aortic calcification. For 237 of the 288 patients with no or moderate calcifications at baseline, X-rays were available for follow-up. During follow-up (mean 2.3 years), aortic calcification progressed in 71 patients (30%). We found that baseline plasma calcium > 9.5 mg/dL and iPTH > 300 pg/mL were associated with progression [odds ratios of 3.1, 95% confidence interval (1.2-8.2) and 4.4 (1.4-14.1), respectively]. Progression of aortic calcification was significantly associated with increased risk of all-cause mortality (hazard ratio: 1.9; 95% CI: 1.2-3.1) and cardiovascular mortality (hazard ratio: 2.7; 95% CI: 1.3-5.6). CONCLUSIONS Aortic calcification progressed in almost a third of the patients during dialysis. Hypercalcaemia and hyperparathyroidism were associated with an increased risk of progression. Progression of aortic calcification was significantly related to an increased mortality risk.

Collaboration


Dive into the Johanna C. Korevaar's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar

Friedo W. Dekker

Leiden University Medical Center

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Sophia E. de Rooij

University Medical Center Groningen

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

M. Goddijn

University of Amsterdam

View shared research outputs
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge