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Biomedical subjects

D Köhler

Publications and source records attributed to D Köhler.

At least 127 records · Page 7Linked to original sources
PubMed1995

[Effectiveness of intermittent self-ventilation after ventilator weaning].

The essential cause for long-term mechanical ventilation with unweanability from respirator is chronic failure of the inspiratory muscles. Principally two different causes exist for chronic respiratory failure: Primary pulmonary diseases with overload or load imbalance of primarily uncompromised respiratory muscles, and neuromuscular diseases with a significant decrease in respiratory muscle capacity. Intermittent nocturnal ventilation (INV) leads to recovery by unloading the respiratory pump. In the present retrospective study we examined the value of INV in the "post-weaning-phase" for previously unweanable, long term ventilated patients. In two years (1993 and 1994) 43 patients who had been ventilated for 57.5 +/- 60.3 days in outward intensive care units (ICU) in a predominantly assisted mode we could wean from the respirator within 8.4 +/- 5.5 days by means of consequently applying an individually adapted, volume cycled weaning regime. In all patients, on admission to our ICU and before discharge blood gases, P0.1, Pimax, breathing frequency and tidal volume were measured during spontaneous breathing. After weaning in about 40% of our patients we decided to initiate INV with intermittent positive pressure ventilation (IPPV). The indication for INV after weaning depended on whether a chronic hypercapnic respiratory failure continued to be demonstrable. In this group of patients, INV was the essential stabilizing factor for continuous weaning success, as the respiratory muscles recovered during the ensuing inpatient phase and the daytime PaCO2 normalised. In most of our patients (14 out of 18) INV could be performed non-invasively via breathing masks. Only 4 out of 18 patients continued to be long-term ventilated invasively via tracheostomy. The remaining patients (25 out of 43) showed normoventilation at daytime during the ensuing inpatient phase so they did not need INV. At the time of the patients' referral to our ICU, there was no predictive value regarding the ultimate indication for INV after weaning from respirator.

Adult↗
PubMed1994

Aerosolized heparin.

Explore the source record for details and available documents.

Administration, Inhalation↗
PubMed1993

A new oxygen applicator for simultaneous mouth and nose breathing.

We have developed a new O2 applicator to try to overcome the problems of long-term oxygen therapy that ensures a sufficient oxygen supply for both nasal and oral breathing and prevents mucosal irritation. Placed on the upper lip, it is unobtrusive. The principle is as follows: due to an enlarged outlet area, turbulence occurs and the oxygen is reduced. Thus, an oxygen cloud is formed that can be inhaled by both mouth or nose. The efficiency of our O2 applicator was compared with a face mask in six healthy subjects and patients with COPD. A similar increase in PO2 was found up to an oxygen flow of 2 L/min for nasal and oral breathing. Mild hypercapnia resulted in three patients with COPD only when a face mask was used and only when patients breathed through the nose. All patients preferred the new applicator.

Adult↗
PubMed1993

[Evaluation of a portable device for measuring maximal inspiratory pressure (Pimax)].

Pimax measurement is useful for quantifying the fatigue of the respiratory muscles (the "respiratory pump" of the mechanics of respiration), for controlling the therapeutic effect of artificial respiration performed at home, and assessment of the possibility of relieving a patient from artificial respiration. So far, such measurement had required complicated set-ups. A portable alternative is now available for Pimax measurement (MPM, distributed by Medanz, Starnberg, Germany). In a prospective study we compared the Pimax values measured via the mouth pressure measuring instrument under test, with the standard laboratory method. Statistical comparison of the measured data yielded a high degree of correlation (r = 0.97) with slight scatter of the individual data around the identity line. The portable instrument tested in this manner thus represents a mobile method yielding reliable Pimax values both on an inpatient and an outpatient basis.

Adult↗
PubMed1993

[Imaging of the normal anatomy of the hand using high resolution magnetic resonance tomography and surface coils].

Magnetic resonance imaging can visualize the soft tissue and the bone marrow of the hand. High spatial resolution requires the use of a surface coil. Signal-to-noise contrast was measured and compared for 3 different coils. Optimal results were obtained with a surface coil with a diameter of 8.5 cm. The wrist and the fingers of 10 volunteers each were examined. Images with a high spatial resolution and a good signal/noise contrast were obtained, enabling the delineation of small structures like Gynon's channel and the median nerve.

Fingers↗
PubMed1992

A double-blind study of two dosage regimens of lomefloxacin in bacteriologically proven exacerbations of chronic bronchitis of gram-negative etiology.

Lomefloxacin has been shown to produce high and sustained concentrations in serum and bronchial mucosa after once-daily administration. This study was designed to assess whether a dose response exists for 400 mg lomefloxacin given once daily or twice daily for 10 days in the treatment of acute bacterial exacerbations of chronic bronchitis of gram-negative etiology. A total of 100 adult patients with acute exacerbations of chronic bronchitis were enrolled at 10 study sites in Germany. Patients with confirmed bacterial pathogens in the baseline sputum culture (once-daily group n = 49, twice-daily group n = 47) were eligible for analysis of bacteriologic and clinical efficacy. The eradication rates for the most frequently isolated baseline pathogens, Haemophilus influenzae, Pseudomonas aeruginosa, and Klebsiella pneumoniae, were at least 75% for both treatment regimens. Overall, once-daily treatment eradicated baseline pathogens in 42 of 49 (85.7%) patients, while twice-daily treatment eradicated pathogens in 43 of 47 (91.5%). This difference was not statistically significant (p = 0.226). Clinically, 47 of 49 (95.9%) patients in the once-daily group and 46 of 47 (97.9%) in the twice-daily group were cured or improved (p = 0.307). Both regimens were well tolerated; there were no differences in the incidence (six patients in each group), types, or severity of adverse events, nor was there clinical evidence of theophylline interaction. The results of this study demonstrate that once-daily treatment with 400 mg lomefloxacin is as effective as twice-daily dosing with 400 mg in patients with acute bacterial exacerbations of chronic bronchitis.

Adult↗
PubMed1991

[Aerosol deposit sample in aspecific bronchial provocation test: a nuclear medicine study for quantification].

A method of standardization of inhalation bronchial provocation tests is induced. The distribution of radioactivity of in- and exhaled 99mTc human albumin (Venticoll) enables an exact calculation of intrabronchial aerosol deposition. The investigations were carried out at twelve normal test persons by using the device of bronchial provocation tests of PARI. Linearity exists between nebulized aerosol quantity in the bag and bronchial aerosol deposition. The intrabronchial aerosol deposition is calculated about 100 mg after emptying the ten liter-bag. Slowly inspiratory maneuvers of vital capacity produce a precision of the inhaled aerosol of about 15 percent.

Aerosols↗
PubMed1991

[Problems of the reproducibility of the inhaled dosage exemplified with the Pari provocation test I apparatus].

The unspecific bronchial provocation test--usually performed with histamine, metacholine or carbachol--is used to determine whether bronchial hyperreactivity is present, and to what degree. Epidemiological studies have shown, that an overlap exists between "healthy" and "sick". There are several reasons for this, the most important being the insufficient reproducibility of intrabronchial deposition and the fact that the total provocation dose is often unknown. The following factors must be taken into account to improve this situation: 1. Only those devices where the particle spectrum is not influenced by the inspiration flow (without additional airstream) should be used to produce aerosols. 2. The air current containing aerosols is vapour saturated when liquid aerosols are produced. As the vapour is derived from the nebulizing solution it forms part of the weight or volume loss, this can be up to 50% of the total weight/volume loss. The aerosol output is far more constant and practically independent of the vapour saturation and the temperature. The intrabronchial dose can therefore not be calculated according to the weight loss of the nebulizer, as this is incorrect. 3. The evaporation of the nebulizing solution leads to an increase in the concentration of the test substance, especially towards the end of the evaporation process. Thus, the volume of the nebulizing solution should always be as large as possible or renewed early. 4. The slower the inhalation maneuver, the less the reproducibility of the intrabronchial deposition is impaired. The intrabronchial deposition varies least, when a slow inspiratory vital capacity maneuver is carried out (inspiration time greater than 8 s). Exhalation should be normal or even rapid, as aerosol deposition is thus increased, due to airway collapse. Breath-holding at the end of inspiration, for about 3-4 seconds, is favourable. 5. The anatomy of the glottic region varies greatly interindividually, influencing intrabronchial deposition. To reduce this to a minimum, the average diameter of the particles should not exceed 2 microns. On the other hand, the diameter of particles should not be under 1 micron, as the inhaled amount of substance is then markedly reduced (volume approximately d3). 6. Reservoirs, storaging the aerosol before inhalation, increase reproducibility, since they stabilize the aerosol due to vapour saturation. Plastic reservoirs must either be of antistatic material, or made antistatic by being filled repeatedly. The reproducibility of intrabronchial deposition is in the range of +/- 15% for the PARI-Provokationstest device I, (determined by radioactive labelling).(ABSTRACT TRUNCATED AT 400 WORDS)

Aerosols↗
PubMed1990

Aerosols for systemic treatment.

The development of a new group of drugs (polypeptides) have recently increased the interest of alternative administration to the enteral route because of its proteolytic activity and the catabolism of the "first-pass effect." Aside from the "needle," the administration in the respiratory tract via aerosol is the method with the best efficiency. But several problems prohibited its spreading: (1) the accuracy and the reproducibility of the inhaled dose (range ca. 1:4); (2) the small amount of inhaled drug in relation to the dose in the aerosol delivery system (range ca. 1%-10%); (3) the fear of allergic reactions of the respiratory system; (4) the variability of the drug transport into the systemic circulation. New approaches and data raise hopes in reducing the problems: (1) aerosol delivery systems with defined particle spectrum and storage systems; slow vital capacity inhaling maneuver; (2) delivery systems that nebulizes nearly the total amount of drug; (3) all studies with the inhalation application of insulin, heparin, ergotamin, ribavirin, aminoglycosides, and "cigarette smoke" do not reveal any relevant allergic reaction; (4) many studies were performed in the last 10 years on the influence of substances and especially of diseases on the transport of molecules through the respiratory tract. Only a few of them are relevant (exogen allergic alveolitis, active sarcoidosis, active smoking). Aerosols for (exogen allergic alveolitis, active sarcoidosis, active smoking). Aerosols for systemic drug treatment seems to be a gained alternative to the "syringe."

Aerosols↗
PubMed1990

Diagnostic modalities for detection of pulmonary embolism in clinical routine: a European survey.

A questionnaire asking for routinely performed modalities to diagnose deep venous thrombosis (DVT) and pulmonary embolism (PE) was sent to 2,500 departments in 23 European countries. Five-hundred-seventy (23%) were received back and evaluated according to hospital size and regional differences. Countries were grouped into: Anglo-Scandinavian (a), German-speaking (g), and Roman (r). Contrast venography is most frequently performed (94%) to diagnose DVT, independent of hospital size and without regional differences. With exception of Doppler ultrasound (71%), noninvasive DVT tests are rarely performed (6-28%). To diagnose PE, pulmonary angiography (PA) and ventilation-perfusion (V-P) scintigraphy are performed in 71%, digital subtraction angiography in only 50%. Frequencies of PE tests strongly depend on hospital size (PA: small hospitals 53-66%, large 83-89%; V-P: small hosp. greater than 80%, large greater than 90%, with 2 exceptions: small German hospitals = 48%, primarily performing only P-scans and large Roman hospitals = 59%, primarily performing PA). Regional differences were also significant (PA: r = 85%, a = 74%, g = 63%, V-P: a = 95%, r = 66%, g = 63%, respectively).

Diagnostic Imaging↗
PubMed1990

[The value of 3D-CT in maxillary surgical diagnosis and therapy planning].

In 25 patients in whom oral surgery was required, we examined what additional information can be obtained via three-dimensional CT compared with conventional transverse CT scans. We showed that D-3 CT facilitated the spatial orientation by complex osseous destructions. Better therapy planning and postoperative control was therefore feasible. However, CT diagnosis continued to be based on transverse scans.

Aged↗