J. M. Bogaard

Long-term results of uvulopalatopharyngoplasty for obstructive sleep apnea syndrome.

Objectives Assessment of the long‐term effect of uvulopalatopharyngoplasty (UPPP) on snoring, excessive daytime sleepiness, and nocturnal oxygen desaturation index (ODI) in patients with obstructive sleep apnea syndrome.

Pulmonary function in Parkinson's disease.

Pulmonary function was investigated in 31 consecutive patients with relatively severe Parkinsons disease. Clinical disability was assessed by Hoehn and Yahr scale, Northwestern University Disability Scale and Websterscore. All patients were on levodopa substitution therapy and used anticholinergics. Pulmonary function was investigated by spirography, determination of a maximal inspiratory and expiratory flow-volume curve and, when possible, maximal static mouth pressures were determined. Peak inspiratory and expiratory flow, maximal expiratory flow at 50% and maximal static mouth pressures were significantly below normal values. Vital capacity, forced inspiratory volume in 1 s and the ratio of forced expiratory volume in 1 s and vital capacity were relatively normal. Nine patients had upper airway obstruction (UAO) as judged by abnormal values for peak inspiratory flow, the ratio of forced expiratory volume in 1 s and peak expiratory flow and the ratio of maximal expiratory and inspiratory flow at 50%. Flow-volume curves were normal in eight patients; four patients demonstrated flow decelerations and accelerations (type A) and 16 had a rounded off flow-volume curve (type B). Type A can be explained by UAO and type B by a combination of decreased effective muscle strength and possible UAO. Overall results of pulmonary function tests in patients without any clinical signs or symptoms of pulmonary disease point to subclinical upper airway obstruction and decreased effective muscle strength in a significant proportion of patients.

Riboflavin-responsive complex I deficiency

Three patients from a large consanguineous family, and one unrelated patient had exercise intolerance since early childhood and improved by supplementation with a high dosage of riboflavin. This was confirmed by higher endurance power in exercise testing. Riboflavin had been given because complex I, which contains riboflavin in FMN, one of its prosthetic groups, had a very low activity in muscle. Histochemistry showed an increase of subsarcolemmal mitochondria. The low complex I activity contrasted with an increase of the activities of succinate dehydrogenase, succinate-cytochrome c oxidoreductase and cytochrome c oxidase. Isolated mitochondria from these muscle specimens proved deficient in oxidizing pyruvate plus malate and other NAD(+)-linked substrates, but oxidized succinate and ascorbate at equal or higher levels than controls. Two years later a second biopsy was taken in one of the patients, and the activity of complex I had increased from 16% to 47% of the average activity in controls. In the four biopsies, cytochrome c oxidase activity correlated negatively with age. We suspect that this is due to reactive oxygen species generated by the proliferating mitochondria and peroxidizing unsaturated fatty acids of cardiolipin. Three of the four patients had low blood carnitine, and all were found to have hypocarnitinemic family members.

Effects of fluticasone propionate in COPD patients with bronchial hyperresponsiveness

Background: Treatment of chronic obstructive pulmonary disease (COPD) with inhaled corticosteroids does not appear to be as effective as similar treatment of asthma. It seems that only certain subgroups of patients with COPD benefit from steroid treatment. A study was undertaken to examine whether inhaled fluticasone propionate (FP) had an effect on lung function and on indices of inflammation in a subgroup of COPD patients with bronchial hyperresponsiveness (BHR). Methods: Twenty three patients with COPD were studied. Patients had to be persistent current smokers between 40 and 70 years of age. Non-specific BHR was defined as a PC20 for histamine of ≤8 mg/ml. Patients received either 2 × 500 μg FP or placebo for 6 months. Expiratory volumes were measured at monthly visits, BHR was determined at the start of the study and after 3 and 6 months, and bronchial biopsy specimens were taken at the start and after 6 months of treatment. Biopsy specimens from asymptomatic smokers served as controls. Results: In contrast to asthma, indices of BHR were not significantly influenced by treatment with FP. Forced expiratory volume in 1 second (FEV1) showed a steep decline in the placebo group but remained stable in patients treated with FP. FEV1/FVC, and maximal expiratory flows at 50% and 25% FVC (MEF50, MEF25) were significantly increased in the FP treated patients compared with the placebo group. Biopsy specimens were analysed for the presence of CD3+, CD4+, CD8+, MBP+, CD15+, CD68+, CD1a, and tryptase cells. FP treatment resulted in marginal reductions in these indices of inflammation. Conclusion: In patients with COPD and BHR, FP has a positive effect on indices of lung function compared with placebo. Bronchial inflammation analysed in bronchial biopsy specimens is only marginally reduced.

Postpneumonectomy pulmonary oedema.

The occurrence of pulmonary oedema was studied retrospectively in 243 patients who underwent pneumonectomy in one hospital from 1975 to 1984. Pulmonary oedema developed in eight of 113 patients who had a right sided pneumonectomy and in three of 130 patients undergoing a left sided procedure. It occurred more commonly in patients requiring a second thoracotomy because of blood loss (in three out of seven patients). There were no significant differences preoperatively in pulmonary function, lung perfusion scans, or cardiovascular condition between patients who subsequently developed pulmonary oedema and those who did not. Postoperative fluid balance was significantly more positive in patients developing pulmonary oedema than in those not developing oedema. Thus pulmonary oedema was associated with right sided pneumonectomy, repeat thoracotomy, and more positive fluid balance.

Expiratory time constants in mechanically ventilated patients with and without COPD.

Abstract Objective: In mechanically ventilated patients, the expiratory time constant provides information about the respiratory mechanics and the actual time needed for complete expiration. As an easy method to determine the time constant, the ratio of exhaled tidal volume to peak expiratory flow has been proposed. This assumes a single compartment model for the whole expiration. Since the latter has to be questioned in patients with chronic obstructive pulmonary disease (COPD), we compared time constants calculated from various parts of expiration and related these to time constants assessed with the interrupter method. Design: Prospective study. Setting: A medical intensive care unit in a university hospital. Patients: Thirty-eight patients (18 severe COPD, eight mild COPD, 12 other pathologies) were studied during mechanical ventilation under sedation and paralysis. Measurements and results: Time constants determined from flow-volume curves at 100%, the last 75, 50, and 25% of expired tidal volume, were compared to time constants obtained from interrupter measurements. Furthermore, the time constants were related to the actual time needed for complete expiration and to the patients pulmonary condition. The time constant determined from the last 75% of the expiratory flow-volume curve (RCfv75) was in closest agreement with the time constant obtained from the interrupter measurement, gave an accurate estimation of the actual time needed for complete expiration, and was discriminative for the severity of COPD. Conclusions: In mechanically ventilated patients with and without COPD, a time constant can well be calculated from the expiratory flow-volume curve for the last 75% of tidal volume, gives a good estimation of respiratory mechanics, and is easy to obtain at the bedside.

Dead space and slope indices from the expiratory carbon dioxide tension-volume curve

The slope of phase 3 and three noninvasively determined dead space estimates derived from the expiratory carbon dioxide tension (PCO2) versus volume curve, including the Bohr dead space (VD,Bohr), the Fowler dead space (VD,Fowler) and pre-interface expirate (PIE), were investigated in 28 healthy control subjects, 12 asthma and 29 emphysema patients (20 severely obstructed and nine moderately obstructed) with the aim to establish diagnostic value. Because breath volume and frequency are closely related to CO2 elimination, the recording procedures included varying breath volumes in all subjects during self-chosen/natural breathing frequency, and fixed frequencies of 10, 15 and 20 breaths x min(-1) with varying breath volumes only in the healthy controls. From the relationships of the variables with tidal volume (VT), the values at 1 L were estimated to compare the groups. The slopes of phase 3 and VD,Bohr at 1 L VT showed the most significant difference between controls and patients with asthma or emphysema, compared to the other two dead space estimates, and were related to the degree of airways obstruction. Discrimination between no-emphysema (asthma and controls) and emphysema patients was possible on the basis of a plot of intercept and slope of the relationship between VD,Bohr and VT. A combination of both the slope of phase 3 and VD,Bohr of a breath of 1 L was equally discriminating. The influence of fixed frequencies in the controls did not change the results. The conclusion is that Bohr dead space in relation to tidal volume seems to have diagnostic properties separating patients with asthma from patients with emphysema with the same degree of airways obstruction. Equally discriminating was a combination of both phase 3 and Bohr dead space of a breath of 1 L. The different pathophysiological mechanisms in asthma and emphysema leading to airways obstruction are probably responsible for these results.

High fat, low carbohydrate, enteral feeding in patients weaning from the ventilator

AbstractObjectiveTo study whether high fat, low carbohydrate enteral nutrition could reduce

Effects of fluticasone propionate on methacholine dose-response curves in nonsmoking atopic asthmatics

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