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Biomedical subjects

C K van der Ent

Publications and source records attributed to C K van der Ent.

At least 37 records · Page 2Linked to original sources
PubMed2001

Forced expiratory manoeuvres in children: do they meet ATS and ERS criteria for spirometry?

The aim of this study was to evaluate the applicability of American Thoracic Society and European Respiratory Society criteria for spirometry in children. Maximal expiratory flow/volume (MEFV) measurements from 446 school-age children, experienced in performing MEFV manoeuvres, were studied and acceptability (start-of-test (backward extrapolated volume as a percentage of forced vital capacity (FVC) ([Vbc%FVC) or as an absolute value (Vbe), end-of-test (forced expiratory time (FET)) and reproducibility criteria (absolute and percentage difference between best and second-best FVC and forced expiratory volume in one second (FEV1) (deltaFVC, deltaFVC %, deltaFEV1 and deltaFEV1 %)) were applied to these manoeuvres. The Vbe%FVC criterion was met by 91.5%, the Vbe <0.15 L criterion by 94.8% and the Vbe <0.10 L by 60.1% of children. Vbe <0.15 L appeared to be a more useful parameter than Vbe%FVC. The FET criterion was met by only 15.3% of children. deltaFVC <0.2 L and deltaFEV1 <0.2 L were met by 97.1% and 98.4%, and deltaFVC <0.1 L and deltaFEV1 <0.1 L by 79.8% and 84.3% of the children, respectively. These criteria appeared to be less useful compared to percentage criteria (deltaFVC % and deltaFEV1 %). Even experienced children did not meet all international criteria for spirometry. However, most of their MEFV curves are useful for interpretation. Based on the performance of these children, a re-evaluation of criteria for maximal expiratory flow/volume measurements in children is proposed.

Adolescent↗
PubMed2000

Flow/volume measurements from childhood to adulthood.

Flow/volume curves are the most frequently used pulmonary function test during childhood. Even preschool children are sometimes able to perform the maximal effort breathing techniques required for this pulmonary function test. The most important conditions for reliable measurement of flow/volume curves at all ages are reported here. In particular, testing atmosphere and equipment, pulmonary function technician requirements, testing procedure, reliability criteria, report making and interpretation are discussed.

Adult↗
PubMed1999

[Immunology in medical practice. XVIII [correction of XVII]. Children with recurrent airway problems: asthma is not always the cause.

Three children, two boys aged 16 and 11 years and a girl aged 16 years, with symptoms resembling asthma had been treated for years with inhaled corticosteroids and beta 2-sympathicomimetics without satisfactory results. It was found that the antibody production after vaccination with 23-valent pneumococcal vaccine was impaired. The symptoms diminished during maintenance treatment with antibiotics in two children and with intravenous immunoglobulins in one. In patients with recurrent respiratory problems, but no specific history of asthma, immunological investigation is warranted, especially in patients whose 'asthma' is accompanied by respiratory infections. When treated for their immunodeficiency these patients show remarkable improvement and the need for steroids often disappears.

Adolescent↗
PubMed1999

Lung function abnormalities and respiratory muscle weakness in children with juvenile chronic arthritis.

In contrast to adult rheumatoid arthritis (RA) little is known about the prevalence, nature and cause of lung function abnormalities in children with juvenile chronic arthritis (JCA). The aim of this study was to determine whether children with polyarticular and systemic onset JCA have lung function abnormalities and if so, whether they are related to pulmonary disease, thoracic and/or muscular involvement. We determined lung function and disability in 31 children with polyarticular and systemic JCA. Respiratory muscle function, thorax expansion and spine mobility were determined in the same patients, as well as in 32 matched healthy children. Peak expiratory flow (PEF) and forced vital capacity (FVC) were significantly reduced in JCA patients, when compared to reference values. Thorax expansion and spine mobility were normal, compared to paired controls. Maximum inspiratory (PI,max) and expiratory (PE,max) pressures were significantly reduced in patients compared to paired control subjects. A positive correlation was found between PE,max and FVC and PEF, an inverse correlation between expiratory pressure and disability. In conclusion, children with polyarticular and systemic juvenile chronic arthritis show a pronounced impairment in respiratory muscle strength, severe enough to cause mild lung function abnormalities and an increase in disability-scores.

Adolescent↗
PubMed1998

Time to peak tidal expiratory flow and the neuromuscular control of expiration.

The ratio of the time needed to reach peak tidal expiratory flow (tPTEF) and the duration of expiration (tE) is used to detect airflow obstruction in young children. tPTEF is decreased in patients with asthma, but knowledge about the physiological determinants of this parameter is scarce. This study examined the relationship between tPTEF and postinspiratory activities of inspiratory muscles and evaluated the effects of changing sensory information from the lung. Airflow patterns and electromyographic (EMG) activity of inspiratory muscles were recorded in seven spontaneously breathing, anaesthetized cats. The trachea was cannulated and, as a result, the larynx and upper airways were bypassed. Changes in postinspiratory muscle activity were induced by changing afferent sensory nerve information (by cooling the vagus nerves, by administration of histamine and by additional application of continuous positive airway pressure (CPAP)). Durations of postinspiratory activities of the diaphragm and intercostal muscles (characterized by their time constants tau diaphr and tau interc) correlated strongly with tPTEF (r=0.85 and 0.77, respectively). Tau diaphr, tau interc and tPTEF were significantly increased during cooling of the vagus nerves (4-8 degrees C) compared with values at 22 and 37 degrees C (p<0.05). Conversely, administration of histamine and CPAP caused significant decreases in tau diaphr, tau interc and tPTEF, which were absent during cooling of the vagus nerves. In conclusion, the time needed to reach peak tidal expiratory flow is highly influenced by the activities of inspiratory muscles during the early phase of expiration which, in turn, depend on the activities of vagal receptors in the lung.

Animals↗
PubMed1996

Tidal breathing analysis as a measure of airway obstruction in children three years of age and older.

This study was designed to evaluate the value and applicability of tidal breathing pattern analysis to assess airflow obstruction in young children. The time needed to reach maximal tidal expiratory flow (TME) divided by total expiratory time (TE) was measured in 228 healthy children 3 to 11 yr of age, 64 patients with asthma, and 12 children with cystic fibrosis. In 70 patients both TME/TE and forced maximal expiratory flow volume (MEFV) parameters were measured. The mean TME/TE in healthy subjects was 43.0 +/- 7.6%. The within-subject reproducibility was high (repeatability index, 5.3%). In the asthmatic patients the mean TME/TE was significantly lower (30.0 +/- 8.2%, p < 0.001), and it increased to 36.5 +/- 7.9% after bronchodilation (n = 44, p < 0.001). The TME/TE level of the subgroup of patients with asthma and FEV1/FVC > or = 0.80 was lower when compared with age-matched normal subjects (30.9 +/- 8.5, p < 0.0001), but it was in a higher range when compared with asthmatics with FEV1/FVC < 0.80 (25.9 +/- 7.9, p < 0.001). In the cystic fibrosis group the mean TME/TE was 27.4 +/- 10.7% without a significant change after bronchodilation. TME/TE correlated significantly with MEFV parameters. Tidal breathing analysis proved easy to perform in children older than 3 yr of age. The TME/TE ratio may be a reliable and simple indicator for airway obstruction.

Airway Resistance↗
PubMed1996

Improvement of tidal breathing pattern analysis in children with asthma by on-line automatic data processing.

The time taken to achieve peak tidal expiratory flow as a proportion of total expiratory time (t PTEF/t E) during tidal breathing (TB) is used as a parameter of airway obstruction in children with asthma. Curve selection bias is one of the most important limitations to the method. This study evaluates three curve selection methods, including a computer program, which on-line selects and analyses TB curves (Masterscreen Paediatric; Jaeger, Germany). TB analysis was performed in 26 children (aged 4-7 yrs) with asthma, before and after methacholine provocation and after subsequent bronchodilatation. Levels and stability of TB parameters derived from computer-selected, unselected and unbiased eye-selected curves were compared. t PTEF/t E ratios of the computer-selected curves agreed well with the unbiased eye-selected curves (limits of agreement -4.8 and +5.8%), but were significantly different from the ratios of unselected curves. Computer-derived t PTEF/t E ratios had the highest level of stability: the reliability coefficient of baseline measurements was 0.96 for computer selection, 0.84 for eye selection and 0.87 for no selection (reliability index = 1 at maximal stability). Tidal volume, respiratory rate, inspiratory and expiratory time were also assessed accurately by the computer program. The mean t PTEF/t E ratio (computer selection) dropped after methacholine provocation (from 30 +/- 9 to 22 +/- 9% at provocative dose at which forced expiratory volume in one second had dropped > or = 20% from baseline (FEV1-PD20 level), p < 0.001) and was restored after bronchodilation (30 +/- 6%; p < 0.001). We conclude that on-line computer analysis is preferable to no selection and to by-eye selection. The use of the program avoids curve selection bias and enhances the applicability of tidal breathing analysis as a measure of airflow obstruction in young children.

Asthma↗
PubMed1995

A special case of congenital adrenal hypoplasia and acute bilateral infantile striatal necrosis.

Isolated mineralocorticoid deficiency is described in a 5-week-old boy. The deficiency progressed to general adrenal insufficiency during the boy's first year of life. The family history suggested X-linked inheritance. At 18 months of age the patient developed acute bilateral infantile striatal necrosis, which might suggest a possible relationship between both entities.

Adrenal Insufficiency↗
PubMed1995

Pulmonary hemosiderosis and immune complex glomerulonephritis.

Two children with a syndrome of pulmonary hemorrhage and immune complex nephritis are reported. Clinical history suggests that pulmonary lesions precede renal abnormalities. Necrotizing glomerulonephritis with granular immune deposits along the glomerular basement membrane was found. Although the etiology of this disease complex is still unknown, the clinical and pathological findings in these patients suggest that immune complex glomerulonephritis is an unusual complication of idiopathic pulmonary hemosiderosis.

Anti-Glomerular Basement Membrane Disease↗
PubMed1992

[Diagnosis of infection in full-term infants born after prolonged status of ruptured membranes: clinical observation is sufficient].

We retrospectively studied our strategy in 80 full-term newborns, born more than 24 hours after rupture of amniotic membranes. Six patients developed clinical signs of sepsis, in four of them sepsis was proven by a positive blood culture. In all cases, clinical symptoms were the first sign of infection. Routine laboratory tests (CRP, leucocyte counts and differentiation, thrombocyte counts) and microbiological investigations (surface cultures, cord blood cultures) were not helpful for the diagnosis of infection at an early stage. These findings are in accordance with the literature. We conclude that after prolonged rupture of membranes with full-term newborns postnatal paediatric care can be limited to a close observation period of 48 hours. There is no need for any further routine investigation of infants without clinical signs of infection.

Bacterial Infections↗
PubMed1989

Antibiotic sclerotherapy for renal cysts.

Seven patients with a large symptomatic renal cyst were treated by aspiration under US guidance and injection of a tetracycline solution (5-8 ml; 1%). All patients were relieved of complaints directly after treatment and US follow-up revealed complete remission or only small residual cysts after one week to twenty-one months. The combination of a strong sclerosing action with a long-acting local antibiotic prophylaxis gives tetracycline an advantage over other sclerosing agents, especially in patients with impaired renal function.

Aged↗