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K G M Moons

Publications and source records attributed to K G M Moons.

At least 19 recordsLinked to original sources
PubMed2007

Validating and updating a prediction rule for serious bacterial infection in patients with fever without source.

AIM: To externally validate and update a previously developed rule for predicting the presence of serious bacterial infections in children with fever without apparent source. METHODS: Patients, 1-36 mo, presenting with fever without source, were prospectively enrolled. Serious bacterial infection included bacterial meningitis, sepsis, bacteraemia, pneumonia, urinary tract infection, bacterial gastroenteritis, osteomyelitis/ethmoiditis. The generalizability of the original rule was determined. Subsequently, the prediction rule was updated using all available data of the patients with fever without source (1996-1998 and 2000-2001, n = 381) using multivariable logistic regression. RESULTS: the generalizability of the rule appeared insufficient in the new patients (n = 150). In the updated rule, independent predictors from history and examination were duration of fever, vomiting, ill clinical appearance, chest-wall retractions and poor peripheral circulation (ROC area (95%CI): 0.69 (0.63-0.75)). Additional independent predictors from laboratory were serum white blood cell count and C-reactive protein, and in urinalysis > or = 70 white bloods (ROC area (95%CI): 0.83 (0.78-0.88). CONCLUSIONS: A previously developed prediction rule for predicting the presence of serious bacterial infection in children with fever without apparent source was updated. Its clinical score can be used as a first screening tool. Additional laboratory testing may specify the individual risk estimate (range: 4-54%) further.

Bacterial Infections↗
PubMed2006

[Treatment of patients with herpes zoster by epidural injection of steroids and local anaesthetics: less pain after 1 month, but no effect on long-term postherpetic neuralgia--a randomised trial].

OBJECTIVE: To assess the effectiveness of a single epidural injection of steroids and local anaesthetics, as a supplement to the standard treatment, for the prevention ofpostherpetic neuralgia in older patients with herpes zoster. DESIGN: Open randomised trial. METHOD: In the period September 2001-February 2004, 598 patients, aged > 50 years, with acute herpes zoster (rash for < 7 days) below dermatome C6, were randomly assigned to receive either standard therapy (oral antiviral agents and analgesics) alone or standard therapy plus an additional single epidural injection of 80 mg methylprednisolone and 10 mg bupivacaine. The primary endpoint was the proportion of patients with zoster-associated pain one month after inclusion. The presence and severity of zoster-associated pain at other time points were secondary endpoints. RESULTS: At one month, pain was reported by 137 (48%) patients in the injection group versus 164 (58%) in the control group (relative risk; RR: 0.83; 95% CI: 0.71-0.97; p = 0.02). After three months, these values were 58 (21%) and 63 (24%), respectively (RR: 0.89; 95% CI: 0.65-1-21; p = 0.47), and at 6 months: 39 (15%) and 44 (17%) (RR: 0.85; 95% CI: 0.57-1-13; p = 0.43). No subgroups were detectable in which the relative risk for pain at one month after inclusion substantially differed from the overall estimate. At one month, the median severity of pain in the injection group was 2 (on a 100-points scale) versus 6 in the control group (p = 0.02). At later follow-up, there was no longer any statistically significant difference in the severity of pain between the two groups. No patient had major adverse events related to the epidural injection. CONCLUSION: A single epidural injection of steroids and local anaesthetics in the acute phase of herpes zoster resulted in a modest decrease in zoster-associated pain in the first month. This treatment did not, however, prevent long-term postherpetic neuralgia.

Aged↗
PubMed2006

The effect of national guidelines on the implementation of outpatient preoperative evaluation clinics in Dutch hospitals.

BACKGROUND AND OBJECTIVES: Preoperative evaluation performed by anaesthesiologists primarily aims to estimate the risk of perioperative complications and to create opportunities to optimize the patients' condition before surgery. In this study an inventory was made of the current practice of preoperative evaluation in Dutch hospitals. It was estimated how many hospitals had implemented an outpatient preoperative evaluation clinic in 2004. Subsequently, current practice was compared with the results of a previous inventory (2000). It was also evaluated to what extent the guidelines of the Dutch Health Council and the Netherlands Society of Anaesthesiology were followed. METHODS: The study consisted of two phases. First, a literature research was performed and pilot interviews were constructed. The interviews were conducted face-to-face with anaesthesiologists in a sample of Dutch hospitals. Based on the results, written questionnaires were constructed. In the second phase these questionnaires were sent to all general and academic hospitals in the Netherlands. RESULTS: In 2004, 74% of the hospitals had an outpatient preoperative evaluation clinic, compared with 50% in 2000. The percentage of hospitals with an outpatient preoperative evaluation clinic available for all elective patients increased from 20% to 52%. CONCLUSIONS: The Dutch guidelines on preoperative evaluation seem to have influenced current practice. An increase in the number of outpatient preoperative evaluation clinics was seen after the guidelines were published. The implementation of an outpatient preoperative clinic seems to warrant that anaesthesiologists are carrying out the activities prescribed by the guidelines. Most hospitals without a clinic aim to implement one in the future.

Anesthesia Department, Hospital↗
PubMed2006

FOLLOWPACE study: a prospective study on the cost-effectiveness of routine follow-up visits in patients with a pacemaker.

AIMS: This communication describes the design of the FOLLOWPACE study. The overall aim of FOLLOWPACE is to quantify the cost-effectiveness of routine follow-up visits in patients with a pacemaker (PM). Specific aims are (i) to quantify the incidence of complications and the quality of life 1 year after PM implantation; (ii) to quantify which baseline characteristics measured during implantation are predictors of the occurrence of complications and quality of life after 1 year; (iii) to determine the added predictive value of follow-up measurements to improve the efficiency of follow-up and to demonstrate which follow-up measurements are redundant. METHODS AND RESULTS: FOLLOWPACE is a prospective, observational, prognostic cohort study. About 40 PM centres in the Netherlands will participate to include about 2,500 patients. Each patient aged >or=18 receiving a PM for the first time is eligible. At baseline, i.e. time of implantation, all potential predictors of complications and quality of life after 1 year are documented. After implantation, follow-up visits will be carried out conforming with routine care, usually three in the first year. At these visits, other potential prognostic predictors will be documented. Primary outcome is the incidence of PM- or cardiac complications at 1 year. Secondary outcome parameters are quality of life and costs after 1 year. CONCLUSION: This study will lead to definition of a more efficient routine follow-up schedule for patients with a PM, aiming to reduce time and energy while preserving the safety of pacing therapy and the prognosis of the patient. The study will ultimately provide evidence-based guidelines for PM follow-up including knowledge of the responsibilities of cardiologists, technicians, and representatives of PM manufacturers.

Appointments and Schedules↗
PubMed2006

Pre-operative detection of valvular heart disease by anaesthetists.

We prospectively estimated the prevalence of heart murmurs in 2522 consecutive adult non-cardiac surgery patients during pre-operative evaluation. Factors that contribute to the detection of a heart murmur were identified, and echocardiography was used to evaluate to what extent a murmur reflected presence of valvular heart disease. A cardiac murmur was detected in 106 patients (prevalence 4.2%, 95% CI: 3.5-5.1%). Multivariable logistic regression analyses showed that age and general physical impression were independently associated with detecting a murmur (p-values < 0.01). In 83 (79%) of the patients with a murmur, an echocardiographic diagnosis was available: 39% had aortic valve abnormalities, 24% had mitral valve regurgitation, 7% had other valvular heart disease and 30% did not have any abnormality. Thus, 58 of the 83 patients had valvular heart disease (positive predictive value using routine cardiac auscultation for diagnosing VHD: 70%, 95% CI: 59-79%). Murmurs in patients younger than 40 years never reflected valvular heart disease. Pre-operative cardiac auscultation seems only reasonable in patients aged 40 years or older. Subsequent echocardiography in these selected patients is necessary.

Adult↗
PubMed2005

Jugular bulb desaturation during coronary artery surgery: a comparison of off-pump and on-pump procedures.

BACKGROUND: Conventional coronary artery bypass surgery has been associated with cerebral injury attributed to cardiopulmonary bypass (CPB) and surgical manipulation of the ascending aorta. Off-pump coronary artery surgery avoids these factors and could prevent cerebral injury. However, moving the heart from its natural position affects the circulation and could compromise cerebral oxygenation and perfusion. We set out to compare episodes of poor global cerebral oxygenation, defined as a jugular bulb saturation less than 50%, between patients randomized to off-pump or (conventional) on-pump coronary artery surgery. METHODS: One hundred and eighty-seven patients were assigned randomly to off-pump or on-pump coronary artery surgery. Oxygen saturation in the jugular bulb (SjO2) was measured during revascularization of the three main coronary vessels in the off-pump group, and at the start of CPB, before rewarming, and after rewarming in the on-pump group. We compared samples with jugular bulb with desaturation (SjO2) < or = 50%) between treatment groups. RESULTS: One hundred and seventy-five patients (81 in the off-pump group [93%] and 94 in the on-pump group [94%]) had complete jugular oxygen saturation data. Thirty-nine patients in the off-pump group (48%) and 25 patients in the on-pump group (27%) had one or more samples with desaturation during revascularization or CPB (odds ratio after adjustment for other factors, 0.39; 95% confidence interval, 0.21-0.73, P<0.01). CONCLUSION: Jugular bulb desaturation occurs more frequently during off-pump coronary artery surgery than during conventional coronary artery surgery.

Adult↗
PubMed2005

Assessing the applicability of scoring systems for predicting postoperative nausea and vomiting.

We have validated two scoring systems for predicting postoperative nausea and vomiting, derived by Apfel et al. and Koivuranta et al. from 1388 adult inpatients undergoing a wide range of surgical procedures. The predictive accuracy of the scoring systems was evaluated in terms of the ability to discriminate between patients with and without postoperative nausea and vomiting (discrimination) and agreement between observed and predicted outcomes (calibration). Discrimination and calibration were less than expected based on previous reports, with both scoring systems providing risk predictions that were too extreme. The area under the ROC curve was 0.63 for Apfel et al.'s scoring system and 0.66 for Koivuranta et al.'s scoring system. Neither of the scoring systems provided a risk threshold for administering anti-emetic prophylaxis that yielded satisfying results in terms of predictive values, sensitivity and specificity. Hence, in their original forms, the scoring systems do not guarantee accurate prediction of the risk of postoperative nausea and vomiting in other patient populations. Koivuranta et al.'s scoring system appears to be more robust across different populations.

Antiemetics↗
PubMed2004

Penalized maximum likelihood estimation to directly adjust diagnostic and prognostic prediction models for overoptimism: a clinical example.

BACKGROUND AND OBJECTIVE: There is growing interest in developing prediction models. The accuracy of such models when applied in new patient samples is commonly lower than estimated from the development sample. This may be because of differences between the samples and/or because the developed model was overfitted (too optimistic). Various methods, including bootstrapping techniques exist for afterwards shrinking the regression coefficients and the model's discrimination and calibration for overoptimism. Penalized maximum likelihood estimation (PMLE) is a more rigorous method because adjustment for overfitting is directly built into the model development, instead of relying on shrinkage afterwards. PMLE has been described mainly in the statistical literature and is rarely applied to empirical data. Using empirical data, we illustrate the use of PMLE to develop a prediction model. METHODS: The accuracy of the final PMLE model will be contrasted with the final models derived by ordinary stepwise logistic regression without and with shrinkage afterwards. The potential advantages and disadvantages of PMLE over the other two strategies are discussed. RESULTS: PMLE leads to smaller prediction errors, provides for model reduction to a user-defined degree, and may differently shrink each predictor for overoptimism without sacrificing much discriminative accuracy of the model. CONCLUSION: PMLE is an easily applicable and promising method to directly adjust clinical prediction models for overoptimism.

Bias↗
PubMed2004

The accuracy of trained nurses in pre-operative health assessment: results of the OPEN study.

We quantified the accuracy of trained nurses to correctly assess the pre-operative health status of surgical patients as compared to anaesthetists. The study included 4540 adult surgical patients. Patients' health status was first assessed by the nurse and subsequently by the anaesthetist. Both needed to answer the question: 'is this patient ready for surgery without additional work-up, Yes/No?' (primary outcome). The secondary outcome was the time required to complete the assessment. Anaesthetists and nurses were blinded for each other's results. The anaesthetists' result was the reference standard. In 87% of the patients, the classifications by nurses and anaesthetists were similar. The sensitivity of the nurses' assessment was 83% (95% CI: 79-87%) and the specificity 87% (95% CI: 86-88%). In 1.3% (95% CI: 1.0-1.6%) of patients, nurses classified patients as 'ready' whereas anaesthetists did not. Nurses required 1.85 (95% CI: 1.80-1.90) times longer than anaesthetists. By allowing nurses to serve as a diagnostic filter to identify the subgroup of patients who may safely undergo surgery without further diagnostic workup or optimisation, anaesthetists can focus on patients who require additional attention before surgery.

Adult↗
PubMed2004

Association between early and three month cognitive outcome after off-pump and on-pump coronary bypass surgery.

OBJECTIVE: To describe the association between cognitive outcome in the first postoperative week and that at three months after both off-pump and on-pump coronary bypass surgery, and to make a direct comparison of early cognitive outcome after off-pump versus on-pump surgery. DESIGN: Randomised trial with an additional prediction study within the two randomised groups. SETTING: Three centres for heart surgery in the Netherlands. PATIENTS: 281 patients, mean age 61 years. INTERVENTIONS: Participants were randomly assigned to off-pump or on-pump coronary bypass surgery. MAIN OUTCOME MEASURES: Cognitive outcome, assessed by psychologists who administered neuropsychological tests one day before and four days and three months after surgery. A logistic regression model was used to study the predictive association between early cognitive outcome, together with eight clinical variables, and cognitive outcome after three months. RESULTS: Cognitive outcome in the first week after surgery was determined for 219 patients and was a predictor of cognitive decline after three months. This association was stronger in on-pump patients (odds ratio (OR) 5.24, p < 0.01) than in off-pump patients (OR 1.80, p = 0.23). Early decline was present in 54 patients (49%) after off-pump surgery and 61 patients (57%) after on-pump surgery (OR 0.73, p = 0.25). CONCLUSIONS: In patients undergoing first time coronary bypass surgery, early cognitive decline predicts cognitive outcome after three months. Early cognitive decline is not significantly influenced by the use of cardiopulmonary bypass.

Cognition Disorders↗
PubMed2003

External validation is necessary in prediction research: a clinical example.

BACKGROUND AND OBJECTIVES: Prediction models tend to perform better on data on which the model was constructed than on new data. This difference in performance is an indication of the optimism in the apparent performance in the derivation set. For internal model validation, bootstrapping methods are recommended to provide bias-corrected estimates of model performance. Results are often accepted without sufficient regard to the importance of external validation. This report illustrates the limitations of internal validation to determine generalizability of a diagnostic prediction model to future settings. METHODS: A prediction model for the presence of serious bacterial infections in children with fever without source was derived and validated internally using bootstrap resampling techniques. Subsequently, the model was validated externally. RESULTS: In the derivation set (n=376), nine predictors were identified. The apparent area under the receiver operating characteristic curve (95% confidence interval) of the model was 0.83 (0.78-0.87) and 0.76 (0.67-0.85) after bootstrap correction. In the validation set (n=179) the performance was 0.57 (0.47-0.67). CONCLUSION: For relatively small data sets, internal validation of prediction models by bootstrap techniques may not be sufficient and indicative for the model's performance in future patients. External validation is essential before implementing prediction models in clinical practice.

Bacterial Infections↗
PubMed2003

Role of history and physical examination in preoperative evaluation.

BACKGROUND AND OBJECTIVE: Since reports have shown that outpatient preoperative evaluation increases the quality of care and cost-effectiveness, an increasing number of patients are being evaluated purely on an outpatient basis. To improve cost-effectiveness, it would be appealing if those patients who are healthy and ready for surgery without additional testing could be easily distinguished from those who require more extensive evaluation. This paper examines whether published studies provide sufficient data to determine how detailed preoperative history taking and physical examination need to be in order to assess the health of surgical patients and to meet the objective of easy and early distinction. METHODS: A MEDLINE search was conducted from 1991 to 2000 with respect to preoperative patient history and physical examination. Altogether, 213 articles were found, of which 29 were selected. Additionally, 38 cross-references, 7 articles on additional testing and 4 recently published papers were used. RESULTS: It is questionable to what extent an extensive history is relevant for anaesthesia and long-term prognosis. With respect to physical examination, it seems unreasonable to diagnose valvular heart disease based on cardiac auscultation only, and it is unclear which method should be used to predict the difficulty of endotracheal intubation. The benefits of routine testing for all surgical patients before operation are extremely limited and are not advocated. CONCLUSIONS: The amount of detail of preoperative patient history and the value of physical examination to obtain a reasonable estimate of perioperative risk remains unclear. Although not evidence based, a thorough history taking and physical examination of all patients before surgery seems important until more evidence-based guidelines become available. Diagnostic and prognostic prediction studies may provide this necessary evidence.

Diagnostic Tests, Routine↗
PubMed2003

The effect of zero-balanced ultrafiltration during cardiopulmonary bypass on S100b release and cognitive function.

Zero-balanced ultrafiltration (ZBUF) might reduce the systemic inflammatory response (SIRS) during cardiopulmonary bypass (CPB) by removing inflammatory mediators. The objective of this study was to determine the effect of ZBUF on postoperative serum S100b levels, a marker of neuronal injury. In addition, the possible effects of ZBUF on postoperative neurocognitive function were assessed. Sixty patients undergoing elective coronary bypass grafting were randomly assigned either to a control group or to a protocol group in which ZBUF was performed. Serum S100b levels were measured five minutes after intubation, at the end of bypass and eight and 20 hours after arrival at the intensive care unit (ICU). Cognitive function was assessed with neuropsychological tests on the day before the operation and the sixth day after surgery. The S100b level at 20 hours after arrival at the ICU was 0.27 g/L (SD 0.16) in the control and 0.25 g/L (SD 0.12) in the group with ZBUF. There were no statistical differences at any time between the two groups. S100b was not detectable in the ultrafiltrate, indicating that these results were not obscured by washout of S100b. Thirteen patients (52%) in the control group and 14 patients (56%) in the ZBUF group showed a cognitive deficit. In conclusion, ZBUF during CPB does not decrease the release of S100b. This result is not affected by washout. ZBUF did not reduce the incidence of early neurocognitive deficits. The role of SIRS in the development of cognitive dysfunction following CPB remains to be resolved.

Aged↗
PubMed2002

Classifying the probability of urinary incontinence in psychogeriatric nursing home patients.

Urinary incontinence (UI) frequently occurs in psychogeriatric nursing home patients. In general the personnel involved in the care for these patients act on incontinence noted. Patients are not monitored or classified according to likelihood or severity of incontinence. This study was conducted to develop and validate a model for the classification of the likelihood of UI in demented nursing home patients. A multi-center cross-sectional study was conducted using data on clinical and functional status of 692 subjects. Subjects were subdivided in a Derivation set of 532 patients and a Validation set of 160 patients. The data were ascertained with questionnaires completed by physicians and nursing staff. All psychogeriatric wards (25) of four Dutch nursing homes were included. Using univariate logistic regression analysis on the derivation set we identified correlates of UI among 22 clinical and functional patient characteristics. Subsequently, we developed a classification model for prevalent UI, including independent patient characteristics by means of multivariable logistic regression. Next, we stratified patients into groups with varying likelihood's of UI based on the model developed. Subsequently, we transformed the model to an easy applicable classification rule for the identification of patient subgroups with high or low likelihood on UI. Finally, the rule was validated on the validation set. The independent multivariate factors associated with urinary incontinence were impaired ADL and mobility, diminished alertness and fecal impaction. After transforming the regression model to an easy classification rule, the scores ranged from 0 to 7. The area under the curve was 0.88 (95% Confidence Interval (CI): 0.85-0.91) in the derivation set. In the validation set a similar area under the curve was obtained (0.90 (95% CI: 0.85-0.95)). Among subjects with none of the associated factors the rule classified 0.5% as incontinent patients. In case all associated factors were present the proportion classified as incontinent increased to 91%. In conclusion, the developed classification rule provides means to stratifying nursing home patients according to their likelihood of being incontinent of urine.

Journal Article↗
PubMed2002

Effect of rewarming speed during hypothermic cardiopulmonary bypass on cerebral pressure-flow relation.

BACKGROUND: Cerebral blood flow is less dependent on arterial blood pressure during hypothermic cardiopulmonary bypass (CPB) compared to warm CPB. Fast rewarming has a more pronounced effect on cognitive performance in the elderly and causes an increased arterio-jugular oxygen content difference. We studied the effect of rewarming and rewarming speed on cerebral pressure-flow relation in adult patients undergoing elective coronary artery bypass surgery with mild hypothermic CPB. METHODS: Fifty patients were randomly assigned to either a slow rewarming strategy (0.24 degrees C/min) or a fast rewarming strategy (0.5 degrees C/min). Cerebral pressure-flow relation was assessed by a transcranial Doppler derived index for cerebral pressure-flow relation (Pressure-flow Index, PFI). The effect of rewarming speed on cerebral pressure-flow relation was assessed by comparing the absolute PFI value after rewarming between the two treatment groups. RESULTS: The mean PFI decreased significantly from 0.73 (standard deviation: 0.28) before rewarming to 0.54 (0.35) after rewarming in the slow rewarming group and from 0.63 (0.29) to 0.48 (0.30) in the fast rewarming group. Absolute PFI after rewarming was not significantly different (mean PFI difference = 0.06; 95% CI = - 0.13; 0.26) between both rewarming strategies. CONCLUSION: Rewarming from mild hypothermic CPB might result in pressure-dependent cerebral blood flow velocity but rewarming speed did not aggravate the effect of rewarming on pressure-flow dependency.

Blood Flow Velocity↗
PubMed2002

Identifying patients for blood conservation strategies.

BACKGROUND: Generally, only the type of operation is used to estimate the need for perioperative homologous blood transfusion. This study quantified the extent to which the estimation could be improved if, in addition, simple patient characteristics were taken into account. METHODS: Retrospective data on 24 509 consecutive adult surgical patients were used to derive and validate three models to predict perioperative homologous transfusion. The first model was a univariable model with type of operation as the only predictor. The second and third models were a full and a simplified multivariable logistic regression model. The performance of the multivariable models was tested in two validation sets: in similar patients who had operations in the same general hospital (internal validation) and in patients who had operations in a university hospital (external validation). The areas under the receiver-operator characteristic (ROC) curve were compared with that found in the derivation set. RESULTS: There were no important differences in characteristics between the derivation and validation sets. The ROC area of the model including surgery only was 0.92 (99 per cent confidence interval (c.i.) 0.91 to 0.94) and that of the full and simplified multivariable models 0.95 (99 per cent c.i. 0.94 to 0.96) and 0.94 (99 per cent c.i. 0.93 to 0.95) respectively. The latter two were significantly different from the first one. In the external validation set the ROC area of the simplified model was 0.84 (95 per cent c.i. 0.83 to 0.86). Patients who had a preoperative haemoglobin level lower than 13 g/dl and underwent major invasive surgery had the highest risk (43 per cent) of transfusion. CONCLUSION: A simple algorithm using type of operation and haemoglobin concentration was effective in identifying patients likely to need perioperative homologous blood transfusion.

Adult↗