Electrolyte monitoring during regional citrate anticoagulation in continuous renal replacement therapy.

Patients with acute kidney injury who need continuous renal replacement therapy with locoregional citrate anticoagulation are at risk of citrate accumulation with disruption of the calcium balance. We aimed to evaluate the safety of detecting citrate accumulation and adjusting electrolyte disbalances during continuous venovenous hemodialysis (CVVHD) in critically ill patients with acute kidney injury using a blood sample frequency every 6 h. A prospective single center study in critically ill intensive care unit patients who suffered from acute kidney injury with the need of renal replacement therapy. We evaluated the deviations in pH, bicarbonate and calcium during CVVHD treatment with local regional citrate anticoagulation. Values indicate median and interquartile range. Severe hypocalcemia (below 1.04 mmol/L) or hypercalcemia (above 1.31 mmol/L) occurred in 10.5% and 4.8% respectively. During treatment changes of systemic ionized calcium, post-filter ionized calcium, pH and bicarbonate were corrected with protocolized adjustments. No arrhythmias or citrate accumulation were seen. The values stabilized after 42 h and after that no statistically significant changes were observed. After 42 h of citrate CVVHD, systemic ionized calcium, pH and bicarbonate levels stabilized. A blood sample frequency every 6 h is probably safe to detect citrate accumulation and to adjust the settings of electrolytes to avoid serious electrolyte disturbances in ICU patients without severe metabolic acidosis or severe liver failure.

Family screening in patients with isolated bicuspid aortic valve : Restriction to those with aortic dilatation is not justified.

AIM: To determine the prevalence of undiagnosed bicuspid aortic valve (BAV) and isolated aortic dilatation in first-degree relatives (FDRs) of patients with isolated BAV and to explore the recurrence risk of BAV in different subgroups of probands with BAV. Recent American College of Cardiology (ACC)/American Heart Association (AHA) Guidelines recommend family screening in patients with associated aortopathy only. METHODS: During follow-up visits, patients with isolated BAV received a printed invitation for their FDRs advising cardiac screening. RESULTS: From 2012-2019, 257 FDRs of 118 adult BAV patients were screened, among whom 63 (53%) index patients had undergone aortic valve surgery (AVS), including concomitant aortic replacement in 25 (21%). Of the non-operated index patients, 31 (26%) had aortic dilatation (> 40 mm). Mean age of the FDRs was 48 years (range 4-83) and 42% were male. The FDR group comprised 20 parents, 103 siblings and 134 offspring. Among these FDRs, 12 (4.7%) had a previously undiagnosed BAV and 23 (8.9%) had an isolated aortic dilatation. FDRs of the probands with previous AVS (n = 147) had a risk ratio for BAV of 2.25 (95% confidence interval (CI) 0.62-8.10). FDRs of the probands with BAV and repaired or unrepaired aortic dilatation (n = 127) had a risk ratio for BAV of 0.51 (95% CI 0.16-1.66). CONCLUSION: Screening FDRs of patients with isolated BAV resulted in a reasonable yield of 14% new cases of BAV or isolated aortic dilatation. A trend towards an increased risk of BAV in FDRs was observed in the probands with previous AVS, whereas this risk seemed to be diminished in the probands with associated aortic dilatation. This latter finding does not support the restrictive ACC/AHA recommendation.

Quality of spirometry and related diagnosis in primary care with a focus on clinical use.

American and European societies' (ATS/ERS) criteria for spirometry are often not met in primary care. Yet, it is unknown if quality is sufficient for daily clinical use. We evaluated quality of spirometry in primary care based on clinical usefulness, meeting ATS/ERS criteria and agreement on diagnosis between general practitioners (GPs) and pulmonologists. GPs included ten consecutive spirometry tests and detailed history questionnaires of patients who underwent spirometry as part of usual care. GPs and two pulmonologists assessed the spirometry tests and questionnaires on clinical usefulness and formulated a diagnosis. In total, 149 participants covering 15 GPs were included. Low agreements were found on diagnosis between GPs and pulmonologists 1 (κ = 0.39) and 2 (κ = 0.44). GPs and pulmonologists rated >88% of the tests as clinically useful, although 13% met ATS/ERS criteria. This real-life study demonstrated that clinical usefulness of routine primary care spirometry tests was high, although agreement on diagnosis was low.

'Exacerbation-free time' to assess the impact of exacerbations in patients with chronic obstructive pulmonary disease (COPD): a prospective observational study.

COPD exacerbations are commonly quantified as rate per year. However, the total amount of time a patient suffers from exacerbations may be stronger related to his or her disease burden than just counting exacerbation episodes. In this study, we examined the relationship between exacerbation frequency and exacerbation-free time, and their associations with baseline characteristics and health-related quality of life. A total of 166 COPD patients reported symptom changes during 12 months. Symptom-defined exacerbation episodes were correlated to the number of exacerbation-free weeks per year. Analysis of covariance was used to examine the effects of baseline characteristics on annual exacerbation frequency and exacerbation-free weeks, Spearman's rank correlations to examine associations between the two methods to express exacerbations and the Chronic Respiratory Questionnaire (CRQ). The correlation between exacerbation frequency and exacerbation-free weeks was -0.71 (p < 0.001). However, among frequent exacerbators (i.e., ≥3 exacerbations/year, n = 113) the correlation was weak (r = -0.25; p < 0.01). Smokers had less exacerbation-free weeks than non-smokers (ß = -5.709, p < 0.05). More exacerbation-free weeks were related to better CRQ Total (r = 0.22, p < 0.05), Mastery (r = 0.22, p < 0.05), and Fatigue (r = 0.23, p < 0.05) scores, whereas no significant associations were found between exacerbation frequency and CRQ scores. In COPD patients with frequent exacerbations, there is substantial variation in exacerbation-free time. Exacerbation-free time may better reflect the burden of exacerbations in patients with COPD than exacerbation frequency does.

Validity, reliability and discriminative capacity of an electronic quality of life instrument (Pelican) for childhood asthma in the Netherlands.

PURPOSE: To assess psychometric properties of the Pelican instrument, an online Dutch self-administered Quality of Life instrument for childhood asthma for scientific and clinical use. METHODS: A cohort study was done in two asthma populations and healthy children. One asthma population had assessment at start, 4 and 8 weeks. The other asthma population and healthy children had one assessment. All children were aged 6-12 years. Children completed the Pelican instrument, Paediatric Asthma Quality of Life Questionnaire, feeling thermometer and Childhood Asthma Control Test. Lung function and fraction exhaled nitric oxide were measured. Parents completed Functional Status II, Asthma Control Questionnaire, Childhood Asthma Control Test questionnaires and symptom diaries. We assessed interpretability, structural validity, internal consistency, reliability, construct and discriminative validity of the Pelican instrument. RESULTS: Eighty-five asthmatic (mean age 8.5 years) and 49 healthy children (mean age 8.4 years) participated. The Pelican instrument has 5 domains with 21 items after factor analysis. Internal consistency was 0.89 (CI 0.85-0.92), domain reliability showed Cronbach's α's from 0.64 to 0.76 and item-to-scale correlations from 0.61 to 0.81. Test-retest reliability was confirmed ICC = 0.88 (CI 0.79-0.93). Construct validity was demonstrated by significant moderate correlations with other relevant asthma outcomes like PAQLQ (r = -0.59, p < 0.01). Discriminative capacity between controlled or uncontrolled asthma (t = 3.20, p < 0.01, Δ = 0.64) and asthma versus healthy subjects (t = 6.31, p < 0.01, Δ = 0.94) was found. CONCLUSIONS: The psychometric properties of the Pelican instrument were acceptable in Dutch paediatric asthma patients between 6 and 12 years old.

A method to study the effect of bronchodilators on smoke retention in COPD patients: study protocol for a randomized controlled trial.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a common disease, associated with cardiovascular disease. Many patients use (long-acting) bronchodilators, whilst they continue smoking alongside. We hypothesised an interaction between bronchodilators and smoking that enhances smoke exposure, and hence cardiovascular disease. In this paper, we report our study protocol that explores the fundamental interaction, i.e. smoke retention. METHOD: The design consists of a double-blinded, placebo-controlled, randomised crossover trial, in which 40 COPD patients smoke cigarettes during both undilated and maximal bronchodilated conditions. Our primary outcome is the retention of cigarette smoke, expressed as tar and nicotine weight. The inhaled tar weights are calculated from the correlated extracted nicotine weights in cigarette filters, whereas the exhaled weights are collected on Cambridge filters. We established the inhaled weight calculations by a pilot study, that included paired measurements from several smoking regimes. Our study protocol is approved by the local accredited medical review ethics committee. DISCUSSION: Our study is currently in progress. The pilot study revealed valid equations for inhaled tar and nicotine, with an R2 of 0.82 and 0.74 (p < 0.01), respectively. We developed a method to study pulmonary smoke retentions in COPD patients under the influence of bronchodilation which may affect smoking-related disease. This trial will provide fundamental knowledge about the (cardiovascular) safety of bronchodilators in patients with COPD who persist in their habit of cigarette smoking. TRIAL REGISTRATION: ClinicalTrials.gov: NCT00981851.

Is physician-diagnosed allergic rhinitis a risk factor for the development of asthma?

BACKGROUND: There is strong evidence that there is a relationship between allergic rhinitis (AR) and asthma, but it is unclear whether there is a causal relation between AR and asthma. The aim of this study was to assess prospectively whether AR is a risk factor for the diagnosis of asthma in a large primary care population. METHODS: We performed a historic cohort study of life-time morbidity that had been recorded prospectively since 1967 in four general practices. Two groups of subjects were selected: (i) patients with diagnosis of AR, (ii) a control group matched using propensity scores. We assessed the risk of physician-diagnosed asthma in patients with physician-diagnosed AR compared to subjects without a diagnosis of AR (controls). RESULTS: The study population consisted of 6491 subjects (n = 2081 patients with AR). Average study follow-up was 8.4 years. In patients with AR, the frequency of newly diagnosed asthma was 7.6% (n = 158) compared to 1.6% (n = 70) in controls (P < 0.001). After adjusting the effect of AR on asthma diagnosis for registration time, age, gender, eczema and socioeconomic status, having AR was a statistically significant risk factor for asthma (hazard ratio: 4.86, P < 0.001, 95% confidence interval: 3.50-6.73, controls as reference). CONCLUSION: A diagnosis of AR was an independent risk factor for asthma in our primary care study population. Having physician-diagnosed AR increased the risk almost fivefold for a future asthma diagnosis.

Interaction in COPD experiment (ICE): a hazardous combination of cigarette smoking and bronchodilation in chronic obstructive pulmonary disease.

Chronic obstructive pulmonary disease (COPD) is a highly prevalent disease, characterised by poorly reversible, obstructive airflow limitation. Alongside other comorbidities, COPD is associated with increased morbidity and mortality resulting from cardiovascular disease - mainly heart failure and ischemic heart disease. Both diseases share an important risk factor, namely, smoking. About 50% of COPD patients are active cigarette smokers. Bronchodilation is the cornerstone of pharmaceutical treatment for COPD symptoms, and half of all COPD patients use long-acting bronchodilating agents. Discussion about these agents is currently focusing on the association with overall mortality and morbidity in COPD patients, of cardiovascular origin in particular. Bronchodilation diminishes the hyperinflated state of the lung and facilitates the pulmonary deposition of cigarette smoke by deeper inhalation into the smaller airways. Smaller particles, as in smoke, tend to penetrate and depose more in these small airways. In addition, bronchodilation indeed increases carbon monoxide uptake in the lungs, an important gaseous compound of cigarette smoke. Since the number of cigarettes smoked is positively correlated to mortality from cardiac events, we therefore hypothesise that chronic bronchodilation increases cardiovascular disease and mortality in COPD patients who continue smoking by increasing pulmonary retention of pathogenic smoke constituents. Indeed, a recent meta-analysis is suggestive that long-acting anticholinergics might increase cardiovascular disease if patients exceed a certain number of cigarettes smoked. To demonstrate the fundamental mechanism of this pathogenic interaction we will perform a randomised placebo-controlled cross-over trial to investigate the effect of maximum bronchodilation on the retention of cigarette smoke constituents. In 40 moderate to severe COPD patients we measure the inhaled and exhaled amount of tar and nicotine, as well during maximum bronchodilation as during administration of placebo. The fraction of retention of tar and nicotine is subsequently calculated for both circumstances and analysed for association with bronchodilation. Further observational cohort studies or randomised clinical trials designed to monitor cardiovascular events may well evaluate the interaction. Since many patients are at risk for this possibly hazardous interaction, its relevance to our society and healthcare is potentially great. The implication will be that the urgency to quit smoking is intensified. Besides, chronic bronchodilation - specifically long-acting bronchodilators - needs to be discouraged in smoking COPD patients that refuse to quit.

Allergic rhinitis management pocket reference 2008.

Allergic rhinitis is a major chronic respiratory disease because of its prevalence, impacts on quality of life and work/school performance, economic burden, and links with asthma. Family doctors (also known as 'primary care physicians' or 'general practitioners') play a major role in the management of allergic rhinitis as they make the diagnosis, start the treatment, give the relevant information, and monitor most of the patients. Disease management that follows evidence-based practice guidelines yields better patient results, but such guidelines are often complicated and may recommend the use of resources not available in the family practice setting. A joint expert panel of the World Organization of Family Doctors (Wonca), the International Primary Care Airways Group (IPAG) and the International Primary Care Respiratory Group (IPCRG), offers support to family doctors worldwide by distilling the globally accepted, evidence-based recommendations from the Allergic Rhinitis and its Impact on Asthma (ARIA) initiative into this brief reference guide. This guide provides tools intended to supplement a thorough history taking and the clinician's professional judgment in order to provide the best possible care for patients with allergic rhinitis. A diagnostic Questionnaire specifically focuses the physician's attention on key symptoms and markers of the disease. When questionnaire responses suggest a diagnosis of allergic rhinitis, a Diagnosis Guide and a simple flowchart then lead the clinician through a series of investigations commonly available in primary care to support the diagnosis. In addition, key aspects of differential diagnosis are illuminated. According to ARIA, allergic rhinitis may be classified as Intermittent or Persistent, and as Mild or Moderate/Severe. The classification of rhinitis determines the treatment necessary, as set out in an ARIA flowchart included in this guide. The guide also includes information about the strength of evidence for efficacy of certain rhinitis treatments, a brief discussion of pediatric aspects, and a glossary of allergic rhinitis medications to assist the clinician in making medication choices for each individual patient. Finally, many patients with allergic rhinitis also have concomitant asthma, and this must be checked. The World Organization of Family Doctors has been delegated by WHO as the group that will be taking primary responsibility for education about chronic respiratory diseases among primary care physicians globally. This document will be a major resource in this educational program.

Asthma management pocket reference 2008.

Asthma is one of the most common chronic airways diseases worldwide, and its prevalence is increasing. Family doctors (sometimes called 'primary care physicians' or 'general practitioners') are frequently an asthma patient's first point of contact with healthcare systems. Disease management that follows evidence-based practice guidelines yields better patient results, but such guidelines are often complicated and may recommend the use of resources not available in the family practice setting. A joint expert panel of the World Organization of Family Doctors (Wonca), International Primary Care Airways Group (IPAG) and the International Primary Care Respiratory Group (IPCRG) offers support to family doctors worldwide by distilling the globally accepted, evidence-based recommendations from the Global Initiative for Asthma (GINA) into this brief reference guide. This guide provides tools intended to supplement a thorough history taking and the clinician's professional judgment in order to provide the best possible care for patients with asthma. Diagnostic Questionnaires developed for children and adults specifically focus the physician's attention on key symptoms and markers of asthma. When questionnaire responses suggest a diagnosis of asthma, Diagnosis Guides then lead the clinician through a series of investigations commonly available in primary care to support the diagnosis. In patients >40 years who smoke, COPD is an important alternative diagnosis, and some key aspects of differential diagnosis are illuminated. According to GINA, the goal of asthma treatment is to achieve and maintain control of the disease symptoms long-term. The physician must first assess the patient's current level of asthma control, then treat asthma in a stepwise manner to achieve and maintain symptom control. Both of these aspects are summarized in figures included in this guide. Finally, the guide also presents a flow chart summarizing management of asthma exacerbations in the acute care setting, and a glossary of asthma medications to assist the clinician in making medication choices for each individual patient. Finally, many patients with asthma also have concomitant allergic rhinitis, and this must be checked. The World Organization of Family Doctors has been delegated by WHO as the group that will be taking primary responsibility for education about chronic respiratory diseases among primary care physicians globally. This document will be a major resource in this educational program.

[Prevalence of and health care consumption for asthma and COPD in relation to ethnicity]. / Prevalentie en zorgconsumptie bij astma en COPD in relatie tot etniciteit.

OBJECTIVE: To determine whether there are differences in prevalence of and health care consumption for asthma and COPD between Dutch people of Turkish, Moroccan and Surinamese origin and indigenous Dutch people. DESIGN: Retrospective. METHOD: Based on data from the 'Second Dutch national study into morbidity and interventions in general practice', we compared the prevalence of asthma and COPD in the different ethnic groups. In addition, we compared the use of various airway medications and the number of general practice contacts between these ethnic groups. RESULTS: We analysed data of 240,067 indigenous Dutch, 2,942 Turkish, 2,416 Moroccan and 3,320 Surinamese subjects. Asthma is more prevalent among Surinamese and seems less prevalent among Moroccans. COPD seems less prevalent among immigrants than among the indigenous Dutch population. Immigrants tend to have less prescriptions of prophylactic maintenance airway medication and they also tend to have less airway-related general practice contacts than indigenous Dutch patients. CONCLUSION: Differences exist in the prevalence of and health care consumption for asthma and COPD between the different ethnic groups in the Netherlands. There seems to be underdiagnosis of COPD in immigrants. Moreover, immigrant asthma and COPD patients are probably undertreated.

Current clinical guideline definitions of airflow obstruction and COPD overdiagnosis in primary care.

The aim of the present study was to establish the agreement between two recommended definitions of airflow obstruction in symptomatic adults referred for spirometry by their general practitioner, and investigate how rates of airflow obstruction change when pre-bronchodilator instead of post-bronchodilator spirometry is performed. The diagnostic spirometric results of 14,056 adults with respiratory obstruction were analysed. Differences in interpretation between a fixed 0.70 forced expiratory volume in one second (FEV(1))/forced vital capacity (FVC) cut-off point and a sex- and age-specific lower limit of normal cut-off point for this ratio were investigated. Of the subjects, 53% were female and 69% were current or ex-smokers. The mean post-bronchodilator FEV(1)/FVC was 0.73 in males and 0.78 in females. The sensitivity of the fixed relative to the lower limit of normal cut-off point definition was 97.9%, with a specificity of 91.2%, positive predictive value of 72.0% and negative predictive value of 99.5%. For the subgroup of current or ex-smokers aged > or =50 yrs, these values were 100, 82.0, 69.2 and 100%, respectively. The proportion of false positive diagnoses using the fixed cut-off point increased with age. The positive predictive value of pre-bronchodilator airflow obstruction was 74.7% among current or ex-smokers aged > or =50 yrs. The current clinical guideline-recommended fixed 0.70 forced expiratory volume in one second/forced vital capacity cut-off point leads to substantial overdiagnosis of obstruction in middle-aged and elderly patients in primary care. Using pre-bronchodilator spirometry leads to a high rate of false positive interpretations of obstruction in primary care.

Are asymptomatic airway hyperresponsiveness and allergy risk factors for asthma? A longitudinal study.

Airway hyperresponsiveness (AHR) is a characteristic feature of asthma, but it is unclear whether asymptomatic AHR is associated with a higher risk of asthma. The present study assessed whether there is an association between asymptomatic AHR in adolescence and asthma in adulthood. The association between allergy and development of asthma was also investigated. A follow-up study of a general population cohort of adolescents was performed 14 yrs after baseline. Respiratory status was assessed at baseline in 1989 and at follow-up in 2003-2004 by a respiratory symptoms questionnaire, spirometry and histamine challenge. Allergy status was also assessed. The respiratory status of 199 subjects was assessed twice. In total, 91 (46%) subjects had the same AHR status in combination with respiratory symptoms at follow-up as at baseline. Adjusted for age, sex, allergy, family history of asthma and smoking history, having asymptomatic AHR was not significantly related to having asthma 14 yrs later (odds ratio (OR) 2.15, 95% confidence interval (CI) 0.67-6.83). For subjects with allergy at baseline, the OR for developing asthma was 4.45 (95% CI 1.46-13.54). Screening for asymptomatic airway hyperresponsiveness in adolescence does not identify subjects at risk of developing asthma. Conversely, the presence of allergy in adolescence does seem to be a risk factor for asthma development.

Primary care spirometry.

Primary care spirometry is a uniquely valuable tool in the evaluation of patients with respiratory symptoms, allowing the general practitioner to diagnose or exclude chronic obstructive pulmonary disease (COPD), sometimes to confirm asthma, to determine the efficacy of asthma treatment and to correctly stage patients with COPD. The use of spirometry for case finding in asymptomatic COPD patients might become an option, once early intervention studies have shown it to be beneficial in these patients. The diagnosis of airway obstruction requires accurate and reproducible spirometric measurements, which should comply with the American Thoracic Society (ATS)/European Respiratory Society (ERS) guidelines. Low acceptability of spirometric manoeuvres has been reported in primary care practices. This may hamper the validity of the results and affect clinical decision making. Training and refresher courses may produce and maintain good-quality testing, promote the use of spirometric results in clinical practice and enhance the quality of interpretation. Softening the stringent ATS/ERS criteria could enhance the acceptability rates of spirometry when used in a general practice. However, the implications of potential simplifications on the quality of the data and clinical decision making remain to be investigated. Hand-held office spirometers have been developed in recent years, with a global quality and user-friendliness that makes them acceptable for use in general practices. The precision of the forced vital capacity measurements could be improved in some of the available models.

Predictive value of lung function below the normal range and respiratory symptoms for progression of chronic obstructive pulmonary disease.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is an insidiously starting disease. Early detection has high priority because of the possibility of early implementation of smoking cessation interventions. An evidence based model for case finding of COPD is not yet available. OBJECTIVE: To describe the early development of COPD, and to assess the predictive value of early signs (respiratory symptoms, lung function below the normal range, reversibility). DESIGN AND METHODS: In a prospective study, based in general practice, formerly undiagnosed subjects (n = 464) were assessed at baseline and at 5 years for respiratory symptoms and pulmonary function. Odds ratios for early signs were calculated (adjusted for age, gender, pack-years at baseline and smoking behaviour during follow-up), and defined as possible indicators of disease progression. RESULTS: Over a 5 year period, the percentage of subjects with obstruction increased from 7.5% (n = 35) at baseline to 24.8% (n = 115) at 5 years. The presence of mild early signs and lung function below the normal range at baseline were related to an increased risk of developing mild to moderate COPD (GOLD I: OR 1.87 (95% CI 1.22 to 2.87); GOLD II: OR 2.08 (95% CI 1.29 to 3.37) to 2.54 (95% CI 1.25 to 5.19)) at 5 years. CONCLUSION: Lung function below the normal range and early respiratory signs predict the development and progression of COPD.

Impact of a spirometry expert system on general practitioners' decision making.

The present study assessed the impact of computerised spirometry interpretation expert support on the diagnostic achievements of general practitioners (GPs), and on GPs' decision making in diagnosing chronic respiratory disease. A cluster-randomised controlled trial was performed in 78 GPs who each completed 10 standardised paper case descriptions. Intervention consisted of support for GPs' spirometry interpretation either by an expert system (expert support group) or by sham information (control group). Agreement of GPs' diagnoses was compared with an expert panel judgement, which served as the primary outcome. Secondary outcomes were: additional diagnostic test rates; width of differential diagnosis; certainty of diagnosis; estimated severity of disease; referral rate; and medication or nonmedication changes. Effects were expressed as odds ratios (ORs) with 95% confidence intervals (CIs). There were no differences between the expert support and control groups in the agreement between GPs and expert panel diagnosis of chronic obstructive pulmonary disease (OR (95% CI) 1.08 (0.70-1.66)), asthma (1.13 (0.70-1.80)), and absence of respiratory disease (1.32 (0.61-2.86)). A higher rate of additional diagnostic tests was observed in the expert support group (2.5 (1.17-5.35)). Computerised spirometry expert support had no detectable benefit on general practitioners' diagnostic achievements and the decision-making process when diagnosing chronic respiratory disease.