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Biomedical subjects

W Vincken

Publications and source records attributed to W Vincken.

At least 37 records · Page 2Linked to original sources
PubMed2000

Absence of bacterial colonization of the airways after therapeutic rigid bronchoscopy without stenting.

Following airway stenting, bacterial colonization of the airways with potentially pathogenic micro-organisms occurs within 4 weeks after treatment in the majority of patients. The objective of this study was to prospectively investigate whether nonstenting therapeutic rigid bronchoscopy (using laser, cryotherapy, mechanical dilatation or debridement) is followed by airway colonization or infection. Protected specimen brush sampling of the central airways and quantitative culture were performed immediately prior to, and 4 weeks after nonstenting therapeutic rigid bronchoscopy in 20 consecutive patients with central airway lesions. Prior to therapeutic bronchoscopy, airway colonization/infection was present in nine of 20 (45%) patients. In these nine patients, 10 different potential pathogens were identified: Streptococcus pneumoniae (four cases), Pseudomonas aeruginosa (three), Haemophilus influenzae (two), and Serratia marcescens (one). Eight of these nine patients had a history of postobstructive infections, of which three were currently being treated with antibiotics. Four weeks following therapeutic bronchoscopy, airway colonization/infection was present in five of 20 (25%) patients, each of whom had airway colonization/infection prior to bronchoscopy. In three of these five patients, the same organisms were found 4 weeks after bronchoscopy as at baseline bronchoscopy. In two of five patients new organisms were identified: one case of Streptococcus viridans and one case of Haemophilus parainfluenzae, both considered to be nonpathogens. In four of nine patients with airway colonization/infection prior to bronchoscopy, the airways were clear of micro-organisms after the procedure. The authors conclude that: 1) nonstenting therapeutic rigid bronchoscopy is not complicated by airway colonization or infection by new potential pathogens; and 2) therapeutic rigid bronchoscopy led to clearing of airway colonization/infection in almost half of the patients studied.

Adult↗
PubMed2000

Volume and cellular content of normal pleural fluid in humans examined by pleural lavage.

Currently, no reliable data are available on the volume or on the cellular content of pleural fluid in normal humans. In analogy with bronchoalveolar lavage (a technique enabling retrieval of small volumes of epithelial lining fluid from the lung), we developed a pleural lavage (PL) technique consisting of injection and retrieval of 150 ml of saline into the right pleural space, performed during a thoracoscopic sympathicolysis procedure in otherwise healthy subjects suffering from essential hyperhidrosis. With urea used as an endogenous marker of dilution, measured mean right-sided pleural fluid volume was 8.4 +/- 4.3 ml. In a subgroup of subjects, we confirmed that right- and left-sided pleural fluid volumes were similar. Expressed per kilogram of body mass, total pleural fluid volume in normal, nonsmoking humans is 0.26 +/- 0.1 ml/kg. Total cell count in the PL fluid of nonsmoking normal subjects yielded a median of 91 x 10(3) white blood cells (WBC) per milliliter of lavage fluid (interquartile range [IR] = 124 x 10(3) cells/ml). Taking into account a measured dilution factor of 18.86, the total WBC count in the original pleural fluid was 1,716 x 10(3) cells/ml. Differential cell counts yielded a predominance of macrophages (median: 75%; IR: 16%) and lymphocytes (median: 23%; IR: 18%). Mesothelial cells (median: 1%; IR: 2%), neutrophils (median: 0%; IR: 1%), and eosinophils (median: 0%; IR: 0%) were only marginally present. There were no significant differences between males and females or between right- and left-sided pleural fluid in total and differential cell counts. In contrast, in smokers a small but statistically significant increase in pleural fluid neutrophils (median: 1%; IR: 2%; p < 0.015) was observed. In conclusion, PL performed during thoracoscopy for sympathicolysis allowed for the first time determination of the volume and of the total and differential cell contents of the pleural fluid present in normal human pleura.

Adolescent↗
PubMed1999

A source of experimental underestimation of aerosol bolus deposition.

We examined the measurement error in inhaled and exhaled aerosol concentration resulting from the bolus delivery system when small volumes of monodisperse aerosols are inspired to different lung depths. A laser photometer that illuminated approximately 75% of the breathing path cross section recorded low inhaled bolus half-widths (42 ml) and negative deposition values for shallow bolus inhalation when the inhalation path of a 60-ml aerosol was straight and unobstructed. We attributed these results to incomplete mixing of the inhaled aerosol bolus over the breathing path cross section, on the basis of simultaneous recordings of the photometer with a particle-counter sampling from either the center or the edge of the breathing path. Inserting a 90 degrees bend into the inhaled bolus path increased the photometer measurement of inhaled bolus half-width to 57 ml and yielded positive deposition values. Dispersion, which is predominantly affected by exhaled bolus half-width, was not significantly altered by the 90 degrees bend. We conclude that aerosol bolus-delivery systems should ensure adequate mixing of the inhaled bolus to avoid error in measurement of bolus deposition.

Administration, Inhalation↗
PubMed1999

Evidence of acinar airway involvement in asthma.

We investigated acinar airway involvement in 20 patients with stable asthma, using the phase III slope analysis of the multiple breath N2 washout previously applied in a group of patients with COPD (Am. J. Respir. Crit. Care Med. 1998;157:1573-1577). This technique quantifies severity of conductive and acinar components of ventilation maldistribution separately, through indices S(cond) and S(acin), which increase when respective ventilation inhomogeneities increase. We also investigated the effect of salbutamol inhalation on S(cond) and S(acin) in patients with asthma and compared it with that obtained in patients with COPD. Baseline measurements in the patients with asthma show that (1) acinar ventilation inhomogeneity was indeed abnormal in patients with asthma (S(acin) = 0.195 +/- 0.026 L-1) despite the normal diffusing capacity in this group; S(acin) values were intermediate between those obtained in unaffected individuals and patients with COPD, and that (2) conductive ventilation inhomogeneity was abnormal in the patients with asthma (S(cond) = 0.076 +/- 0.006 L-1) but similar to that obtained in the patients with COPD. Measurements after salbutamol inhalations showed significant changes in S(cond) and S(acin) only in the patients with asthma (p < 0.001). This study primarily demonstrated significant, but partially reversible, acinar airway impairment in patients with asthma, as compared with the more severe baseline acinar airway impairment in patients with COPD, which was not reversible after salbutamol inhalation.

Adult↗
PubMed1999

Systemic effects of inhaled fluticasone propionate and budesonide in adult patients with asthma.

We assessed the systemic effects of budesonide (BUD) and fluticasone propionate (FP) in 23 patients with asthma, using a double-blind, placebo-controlled, double-dummy, and cross-over design. The following five treatments were given in a randomized order for 1 wk with a washout period in between of 2 wk: (1) placebo; (2) FP, 200 micrograms twice a day, inhaled from a Diskhaler; (3) FP, 1,000 micrograms twice a day, inhaled from a Diskhaler; (4) BUD, 200 micrograms twice a day, inhaled from a Turbuhaler; and (5) BUD, 800 micrograms twice a day, inhaled from a Turbuhaler. The primary variable was the area under the curve of serum cortisol versus time (AUC0-20), derived from serum samples taken every 2 h over a 20-h period following the last evening dose at 10:00 P.M. The lower doses of BUD and FLU did not cause any adrenal suppression. Compared with placebo, however, FP (1, 000 micrograms, twice daily and BUD (800 micrograms, twice daily) decreased the AUC0-20 by 34 and 16%, respectively. Fluticasone (1,000 micrograms, twice daily) was more suppressive than BUD (800 micrograms, twice daily) (p = 0.0006). The FEV1, measured the morning after the last inhalation, was significantly higher after the active treatments, compared with placebo (p < 0.02), but did not differ between all active treatments. We conclude that high doses of BUD and FP (in particular the latter), inhaled via their respective dry powder inhalers for 1 wk, result in a measurable systemic activity in patients with asthma.

Administration, Inhalation↗
PubMed1999

Bacterial colonization of central airways after stenting.

Airway stenting (AS) is increasingly used in the management of obstructive lesions of the central airways. Although retention of secretions and infection have been reported as complications of AS, the microbiological consequences of AS have not yet been evaluated. In this study, we prospectively performed protected specimen brush (PSB) sampling of the airways, before and 3 to 4 wk after AS, in 14 consecutive patients (65 +/- 17 yr), suffering from bronchial (5), extensive esophageal (2), thyroid (1), and adenocystic (1) carcinoma, stenotic tracheal burn lesions (2), postintubation stenosis (2), and Wegener's granulomatosis (1). A cutoff value of >/= 10(2) colony-forming units (cfu). ml(-)(1) was considered diagnostic for airway colonization (AC). PSB results were related to the presence and degree of secretion retention (SR) at the level of the stent. In five of the 14 patients, AC was present prior to AS; in three of these, potentially pathogenic microorganisms (PPM) were identified. After AS, AC was found in 11 (including seven patients without prior AC) of the 14 patients. In six of these patients, one or more PPM were present (Pseudomonas aeruginosa [4], Staphylococcus aureus [3], Streptococcus pneumoniae [1], Klebsiella spp. [1]). Although AC tended to be associated with the presence of SR (PSB >/= 10(2) cfu. ml(-)(1) in 10 of 12 SR-positive and in zero SR-negative cases; PSB < 10(2) cfu. ml(-)(1) in two SR-positive and in two SR-negative cases), statistical significance was not reached (Fisher exact test, p = 0.06). We conclude that AS is frequently followed by AC, the majority of which occurs in patients without AC prior to AS, and is caused by PPM. In no case, however, AC was associated with clinical signs of infection. AC tended to be associated with SR in the stent.

Aged↗
PubMed1999

Screw-thread vs Dumon endoprosthesis in the management of tracheal stenosis.

STUDY OBJECTIVES: A frequent complication of the widely used Dumon silicone stent is its tendency to migrate when used in tracheal stenosis. We compared the clinical efficacy and complications (including migration) of the Dumon stent with a screw-thread stent, a device with an increased stent-to-wall contact surface and, theoretically, less tendency to migrate. DESIGN: Retrospective case analysis. SETTING: Academic hospital. MATERIALS AND METHODS: Forty-six patients with tracheal stenoses (23 benign and 23 malignant) requiring the placement of 50 stents (29 Dumon and 21 screw-thread) were studied. In 26 patients Dumon stents were used, and in 20 patients screw-thread stents were used. Both patient groups had comparable clinical and stenosis-related characteristics. RESULTS: Stent insertion and follow-up were uneventful in both the Dumon and the screw-thread insertions, respectively: 62% vs 67% (not significant). There were seven migrations in the Dumon group, compared to only one migration in the screw-thread group, respectively: 24% vs 5%. This difference did not reach statistical significance (p = 0.1). All of the migrations occurred in the benign stenosis group, and none occurred in the malignant-stenosis group, respectively: 8 of 23 vs 0 of 23, p = 0.004. Within the benign-stenosis group, the Dumon stent had a significantly increased risk for migration when compared to the screw-thread stent, respectively: 7 of 13 vs 1 of 11, p = 0.033. CONCLUSIONS: The screw-thread stent and the Dumon stent are equally effective in the management of tracheal stenosis. There is a general trend toward a decreased migration rate, and a significantly lower risk for migration in patients with benign tracheal stenosis. The (less expensive) screw-thread stent may represent an attractive alternative in the management of tracheal stenosis in general, and may be preferable to the Dumon stent in treating benign tracheal stenosis.

Aged↗
PubMed1998

Thoracoscopic T2-T3 sympathicolysis for essential hyperhidrosis in childhood: effects on pulmonary function.

Thoracoscopic T2-T3 sympathicolysis (TS) is a minimally invasive treatment for patients suffering from severe, refractory essential hyperhidrosis (EH). TS has previously been shown to be safe and efficacious in children. In order to examine the effects of TS on respiratory function, pulmonary function tests (PFT) were performed prior to and 6 weeks and 6 months after TS in 12 children with EH (3 boys; mean age 12.8+/-2.5 years). Small asymptomatic decreases in forced expiratory volume in one second (FEV1; -2%), forced expiratory flow after expiration of 75% of vital capacity (FEF75; -9.6%), total lung capacity (TLC; -1%), transfer factor for diffusion of carbon monoxide (T(LCO); -7.6%), and transfer coefficient for diffusion of carbon monoxide (K(CO); -1.5%) were observed 6 weeks after TS. These changes are comparable to those observed in adults but did not reach statistical significance in small children. In line with observations in adults, TLC (and T(L,CO)) returned to baseline values 6 months after TS, whereas FEV1, FEF75, and K(CO) remained at their 6-week level. In conclusion, TS causes only small, statistically insignificant, and asymptomatic decreases in pulmonary function in children. TS can, therefore, be considered a safe treatment option in children suffering from severe, refractory EH.

Adult↗
PubMed1998

Conductive and acinar lung-zone contributions to ventilation inhomogeneity in COPD.

We investigated ventilation inhomogeneity in patients with chronic obstructive pulmonary disease (COPD) through use of the multiple breath N2 washout test (MBW). From an alveolar slope analysis throughout the MBW, we derived two indices, S(cond) and S(acin), as a measure of ventilation inhomogeneity in conductive and acinar zones of the lungs, respectively (J. Appl. Physiol. 1997;83:1807-1816). We evaluated the relationship of S(cond) and S(acin) to standard lung-function indices by means of a principal-components factor analysis, which linked correlated indices to independent factors accounting for 81% of the total variance within the COPD group. S(acin) was linked to the so-called acinar lung-zone factor, which also comprises diffusion capacity measurements. S(cond) was linked to the so-called conductive lung-zone factor, which also comprises specific airway conductance (S(Gaw)) and forced expiratory flows. FEV1 divided by FVC (FEV1/FVC) was the only variable linked to both the conductive and the acinar lung-zone factors. The fact that S(cond) and S(acin) were linked to independent factors provides statistical confirmation of the hypothesis that S(cond) and S(acin) reflect independent lung alterations, whereas FEV1/FVC behavior indicates a combined conductive and acinar contribution to airways obstruction.

Airway Resistance↗
PubMed1998

Thoracoscopic splanchnicolysis for the relief of chronic pancreatitis pain: experience of a group of pneumologists.

Intractable pain is the most invalidating symptom in patients suffering from chronic pancreatitis. Anatomical interruption of the major afferent pain nerves is indicated in severe refractory cases. Among the various techniques and sites of interruption, thoracoscopic splanchnicectomy has emerged as an efficient alternative for the more aggressive open surgical splanchnicectomy, and for the (solely temporarily efficacious) transcutaneous neural blocks, which moreover bear some serious complications. Until now, all reports on thoracoscopic splanchnicectomy were typically surgical, using video-assisted thoracoscopic surgery techniques, double-lumen intubation, and so on. In analogy with thoracoscopic upper dorsal T2-T3 sympathicolysis for essential hyperhidrosis, a simplified thoracoscopic splanchnicolysis technique used in 8 patients suffering from either severe refractory chronic pancreatitis pain (7 patients) or postsurgical epigastric pain is described. Pain control was achieved in 5 of the 7 patients with chronic pancreatitis with a short (20+/-8 min) intervention, short hospitalization (2 days), and simple (single-lumen intubation, no chest drains) procedure. Thus, this simplified thoracoscopic splanchnicolysis technique may represent a valid alternative in the often difficult treatment of refractory chronic pancreatitis pain or other upper abdominal pain.

Abdominal Pain↗
PubMed1998

Effect of body posture on spirometric values and upper airway obstruction indices derived from the flow-volume loop in young nonobese subjects.

STUDY OBJECTIVE: To define the effect of changes in body posture on flow-volume loops (FVLs) and four commonly used indices of upper airway obstruction (UAO) in young, nonobese normal subjects. DESIGN: Prospective comparative study. SETTING: Pulmonary function laboratory at an academic hospital. PARTICIPANTS: Thirty-one normal volunteers. INTERVENTION: At least three FVLs per posture were obtained in the sitting, supine, and left and right lateral recumbent postures while maintaining a constant position of the head and neck in relation to the trunk. In each body posture, the largest observed flow rates were used to calculate the UAO indices. RESULTS: When subjects changed from the sitting to each of the three recumbent postures, all spirometric values decreased significantly (p<0.0001). However, among the four UAO indices, only the FEV1/peak expiratory flow ratio increased significantly (although only slightly, by 2.9 and 4.4%, respectively) in both the right and left lateral recumbent postures (p<0.0001), but not in the supine posture. None of the subjects developed an inspiratory or expiratory plateau on the FVL in any of the three recumbent postures. CONCLUSIONS: In young, nonobese normal subjects, recumbency does not induce UAO, at least not detectable by changes in the FVL configuration or in UAO indices derived from the FVL. Furthermore, the study provides the upper limits of recumbency-related changes in the various UAO indices for young, nonobese normal subjects.

Adult↗
PubMed1997

Actual use of inhaled corticosteroids and risk of hospitalisation: a case-control study.

BACKGROUND: The relationship between therapy and adverse outcome in asthma is debated especially for naturally occurring situations. This is due in part to insufficient information regarding actual use of medications. OBJECTIVE: This study was conducted to clarify the relationship between actual intake of anti-asthma drugs and asthma hospitalisation, considered as an outcome. METHODS: A case-control study was performed. Patients hospitalised for an asthma exacerbation were matched to community controls identified in surrounding general practices. Patients were questioned to identify prior use of anti-asthma medications, level of use of inhaled corticosteroids and attitude towards therapy. RESULTS: Twenty-three cases and 31 matched controls were interviewed. Cases tended to have more severe asthma than controls, as judged by more frequent use of oral corticosteroids. Cases tended to make more frequent use of oral xanthines and inhaled anticholinergics, but the proportion of patients using inhaled beta 2-adrenoceptor agonists and inhaled corticosteroids was similar in both groups. Use of lower doses of inhaled corticosteroids was associated with an increased risk of hospitalisation, while higher dosage was associated with decreased risk. Cases and controls differed as to their answers to a questionnaire concerning attitudes: cases expressed less interest in optimal usage of inhaled corticosteroids than controls; they also expressed more confidence in inhaled beta 2-agonists. When both risks were combined, overconfidence in beta 2-agonists and suboptimal use of inhaled steroids, the relationship with hospitalisation was significant (OR 5.5, 95% CI 1.1; 26.1). CONCLUSION: The results suggest that patients' attitudes to inhaled corticosteroids and actual consumption of these medications are directly related to adverse outcome in asthma.

Administration, Inhalation↗
PubMed1997

Plasma catecholamine concentrations in essential hyperhidrosis and effects of thoracoscopic D2-D3 sympathicolysis.

Essential hyperhidrosis (EH) is caused by a poorly understood overactivity of the sympathetic fibres passing through the upper dorsal sympathetic ganglia D2 and D3. These ganglia are also in the pathway of the sympathetic innervation of the heart and lungs. Therefore, although the predominant sympathetic neurotransmitter at the eccrine sweat glands is acetylcholine, the plasma concentration of noradrenaline (NA) (which is the main sympathetic neurotransmitter at the end organs including the heart and the lungs) may be elevated. Furthermore, as there are some indications for generalized sympathetic overactivity in EH, the plasma concentration of adrenaline (A) may also be elevated. Plasma levels of NA and A were therefore determined in 13 EH patients before and after thoracoscopic D2-D3 sympathicolysis (TS). Preoperative NA and A plasma levels were all within the normal limits used in our laboratory. After TS, mean NA plasma levels are significantly decreased, whereas mean A are unchanged. We conclude that sympathetic overactivity in EH is limited to the upper dorsal sympathetic ganglia and that some of the cardiovascular and pulmonary effects that are observed after TS may be associated with the decrease in NA.

Adolescent↗
PubMed1997

Severe community-acquired pneumonia caused by atypical organisms.

Three cases of community-acquired pneumonia (CAP), requiring intensive care admission, are presented. The clinical picture of a "typical" bacterial pneumonia in the three patients led to an initial empirical treatment with amoxicillin clavulanic acid or 2(nd) generation cephalosporins. The treatment had to be changed in all three because of clinical failure. Erythromycin was added to the therapy with good clinical evolution. Serology confirmed atypical organisms to be responsible. Only the chest X-ray might have suggested an "atypical" or a "viral-like" agent. A proposition is made for an empirical combination of antibiotics in severely ill patients with CAP with more than unilobar consolidation.

Adult↗
PubMed1997

A prospective, randomised study comparing the efficacy of talc slurry and bleomycin in the treatment of malignant pleural effusions.

In comparative studies with other agents, insufflated talc has been shown to be the most effective agent in achieving chemical pleurodesis in patients with malignant pleural effusions. The objective of this study is to compare the efficacy of talc administered as slurry (5 g in 50 mL saline) via tube thoracostomy with that of bleomycin (1 mg/kg in 50 mL saline) (which is the most effective agent other than talc). In a randomised, prospective comparative study, twenty-six consecutive patients with proven malignant pleural effusions (recurrent after at least two pleuroscenteses) in whom no pleurodesis attempt had yet been made, and who were symptomatic, had a Karnovski index < or = 50, and an expected survival of one year or less, were included. Therapeutic failure was defined as recurrent pleural fluid > or = 50% of initial volume or requiring pleurocentesis. Recurrence rates (25% vs 21.4%, NS), fever (25% vs 35.7%, NS), pain (0% both groups) and survival (3.75 +/- 3 vs 5.82 +/- 7.15 months, NS) did not differ between bleomycin or talc treated patients. There were no major complications (e.g., empyema) or side-effects. In conclusion, talc slurry and bleomycin are equally effective in achieving chemical pleurodesis via thoracostomy in patients with malignant pleural effusions, and the safety profile of both agents is similar. Since talc is substantially less expensive than bleomycin, talc slurry probably represents the agent of choice for chemical tube thoracostomy pleurodesis.

Adult↗