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Biomedical subjects

W Tölle

Publications and source records attributed to W Tölle.

At least 19 recordsLinked to original sources
PubMed1980

Evaluation of surfactant-like effects of commonly used remedies for colds.

Volatile aromatics, eucalyptol, eucalyptus oil, camphor and menthol were spread on synthetic DPL films and pulmonary surfactants; the initial surface pressure of the surfactants was measured and the additional surface pressure increment recorded. Eucalyptol was allowed to be inhaled by rabbits and lung compliance was monitored. Under our experimental conditions the volatile aromatics exhibited surfactant-like effects, namely a decrease in surface tension between water and air and thus improved lung compliance values in vivo.

Animals↗
PubMed1979

The mechanical, enzymatic and morphological changes in acute pulmonary insufficiency following the production of a haematoma in rabbits.

The production of a haematoma in the hindleg of rabbits represents a simplification of post-traumatic models. The lungs, one of the target organs, show similar micromorphological alterations to those described in traumatised human beings. The lungs of rabbits, bearing a hindleg haematoma for 24 hr, showed a significantly increased incidence of micromorphological lung alterations compared to the control group. Moreover, measurement revealed a significantly decreased lung compliance within the haematoma groups. It was demonstrated that whether the haematoma was subcutaneous or intramuscular, similar alterations were seen in lung histology, and in lung compliance values. Studies on the activity of superoxide dismutase in lung tissue homogenates demonstrated a significant decrease in those rabbits having had a haematoma intramuscularly for 24 hr.

Acute Disease↗
PubMed1979

[Anesthsiological experiences in experimental surgery].

The paper reports experience with methods of anaesthesia in rabbits, rats, mice, guinea-pigs, pigs, sheep, baboons, dogs and cats. Special problems of handling, mode of injection and intubation are discussed. A comprehensive survey of literature provides further information about the proposed patterns of anaesthesia and informs about other anaesthetic methods, not practised by the authors.

Alcuronium↗
PubMed1977

[An experimental study on the pathogenesis of the acute pulmonary insufficiency (author's transl)].

Parameters of the lungs as Compliance PaCO2, PaO2, have been measured in connection with experimental, pathophysiological insults like hematoma, bone marrow intravasation and hemorrhage, in rabbits. Concerning the compliance quotient, a statistically proved decrease was found within the groups, which have had a hematoma. Moreover, the histological picture of the lungs from rabbits with a hematom showed perivascular and intersitial edema and considerable atelectases. Serum of animals, which have had a hematom for at least 24 h has been fractionated by gel chromatography; low molecular weight substances of the fractionated serum were injected into healthy recipients. Thereafter, measurement of the centralvenous pressure suggests the appearance of substances, pharmacodynamic similar to 5-Hydroxytryptamin, in blood of rabbits with hematom.

Animals↗
PubMed1977

[Influence of ventilatory pattern on the functional situation of the lung during inhalation anaesthesia. Part I: Spontaneous breathing versus IPPB (author's transl)].

After five hours breathing spontaneously enflurane, halothane and methoxyflurane only the rabbits under enflurane showed, apart from a mild respiratory acidosis, no deterioration of pulmonary functional situation. Halothane and methoxyflurane exhibited under the same conditions a significant worsening of elastic behaviour of the lung. The structural bases of the mechanical impairment were atelectasis, dystelectasis and interstitial edema. Postnarcotic examination of lung extracts in the wilhelmy balance showed no abnormalities in the spontaneously breathing animals. If one compares these findings, indicating an irritation of surfactant by halothane and methoxyflurane with the results after IPPB the conclusion can be made that under these circumstances IPPB represents an additional stress for the alveolar lining layer. From the theoretical point of view therefore it would be advisable in patients with surfactant deficiencies to avoid the combination of halothane or methoxyflurane with IPPB. The use of PEEP will be discussed in part II. The value of periodical sighs could not be established under our conditions. Longer periods of spontaneous breathing seem only advisable under halothane but not under enflurane or methoxyflurane because their respiratory depressant properties.

Acidosis, Respiratory↗
PubMed1977

[The significance of the ventilation pattern for the functional situation of the lung in inhalation anaesthesia. Part II: PEEP (author's transl)].

The present study demonstrates the beneficial effects of PEEP on the functional behavior of rabbit lungs after five hours anaesthesia with halothane and methoxyflurane. Instead of a highly significant decline of lung compliance as was seen after spontaneous breathing and IPPB, PEEP led to a constant though statistically non-significant rise of this criterion. Blood gas values, too, demonstrated clearly the superiority of this ventilatory pattern. In contrast to former investigations there were no histological findings indicating any structural damage to the lung. Postanaesthetic examinations of lung extracts in the Wilhelmy balance showed no deterioration after PEEP. From these experimental findings it is concluded that patients suffering from surfactant deficiencies will benefit from a moderate PEEP during anaesthesia with halothane or methoxyflurane.

Anesthesia, Inhalation↗
PubMed1977

[The influence of Halothane on surfactant activity of the lung (author's transl)].

Halothane, momentarily the most popular inhalation anaesthetic, was examined in respect of its surfactant irritating properties in 13 rabbits. After five hours IPPB-anaesthesia with this compound there was a highly significant fall of the compliance quotient (CQ), at the moment the most reliable criterion for the surfactant activity "in situ", from 3.34 to 2.76. Lung histology revealed patchy atelectasis, dystelectasis and interstitial edema. In contrast to this remarkable mechanical and structural deterioration, blood gas analyses showed a surprising stability of gas exchange, hinting a tremendous functional reserve. Postnarcotic examination of lung extracts in the Wilhelmy balance exhibited no persistent damage of the specific alveolar lining layer. On the basis of these experimental findings we recommend that halothane should not be used in patients with preexisting impairment of pulmonary surfactant system.

Animals↗
PubMed1976

Prenatal prediction of respiratory distress syndrome. Measurement of surface properties and Lecithin/Sphingomyelin ratio in human amniotic fluid.

118 samples of amniotic fluid were taken from 102 patients in the 25th to the 43th week of pregnancy by amniotomy or by transabdominal amniocentesis. 76 samples were obtained from patients with normal pregnancies without evidence for either induction or retardation of lung maturity; they served to establish normal values. In 37 cases samples were taken within 72 hours prior to delivery, the decisive period for the prediction of a respiratory distress syndrome. In seven cases a respiratory distress syndrome occured which was diagnosed by an independent pediatrician. The following tests were performed for all samples: 1. Surface tension was measured biomechanically using the Wilhelmy balance and a surface tension area diagram (Fig. 1) was made: A platimum plate is immersed into the liquid placed in the trough; the surface tension is measured via a transducer. The surface film of th liquid to be studied is compressed cyclically from an initial area of 100% to 20% by a moveable barrier and is expanded afterward. Platinum plate and barrier are connected to an X-Y recorder. The surface tension area diagrams are interpreted on the basis of the following criteria: see article 2. The determination of the L/S ratio (simultaneous comparison with the standard method): The method of GLUCK as modified by BORER(planimetric interpretation of the the spots) was employed. Both methods produced normal values. For the biomechanical measurements a classification into three groups was made (25th-30th, 31st-35th, 36th-43rd week of pregnancy) (Tab.I);the L/S ratio showed the usual steep increase from the 36th week of pregnancy onwards. In cases with RDS (Tab.II) surface tension-area-diagrams show high values for gamma max and a slight decrease in surface tension on compression (high gamma min values); the stability index is low, the hysteresis is reduced. Fig. 3. Up to the 34th week of pregnancy the 2:1L/S ratio assumed as the threshold for a sufficient surfactant concentration does not permit a clear interpretation; in subsequent weeks all cases fail to coincide with the normal pattern of distribution (Fig.2). Both the L/S ratio and the criteria of the surface tension area diagrams show significant differences in cases with and without RDS. The prognostic validity of both methods was tested for the probability of predicting occurrence of RDS, probability of RDS occurence and probability of non-occurrence of FDS. The prognostic value seems equal to the L/S Ratio.

Amniotic Fluid↗
PubMed1976

[Biomechanic examination of prenatal lung maturity. Testing of amniotic fluid specimens and lung homogenates on Wilhelmy's scale].

In all traditional methods of determining fetal lung maturity the content of phospholipids in the amniotic fluid is used as parameter. The function of the other parts of the surfactant is not taken into account. The dynamic surface tension measurements using the Wilhelmy balance simulate the interplay of the whole biological system. We have tested 76 specimens of amniotic fluid and 17 lung extracts from 25 weeks' gestation onwards using the biomechanical procedure. In addition, the L/S ratio in the amniotic fluid was determined. There was a correspondence between the values of the amniotic fluid and the lung measured in the same week of pregnancy. The results of the surface tension measurements show a good correlation with the standard method. The following are the advantages of the Wilhelmy balance: results show a small range of dispersion, procedure can be easily learned and carried out quickly and simply.

Amniotic Fluid↗
PubMed1976

[The influence of methoxyflurane (penthrane) on surface activity of the lung (author's transl)].

Methoxyflurane, at the moment the most potent inhalation anaesthetic, was examined in respect of its surfactant irritating properties in the rabbit. After a five hour anaesthesia with this compound there was, compared with a control group of animals which underwent only mechanical ventilation with room air for the same period, a significant decline of the compliance quotient from 2.99 to 2.55, indicating a relevant impairment of alveolar lining surfactant. A concomitant fall of arterial PaO2 from 84.8 to 71.3 mm Hg showed the resulting deterioration of respiratory function. Postanaesthetic preparations of these lungs examined using the Wilhelmy balance exhibited a significant fall of the stability index from 1.73 to 1.25, though hysteresis remained unaffected. Lung histology showed interstitial edema and patchy atelectasis, features which are found also in the early stages of post-traumatic pulmonary insufficiency. On this basis we recommend that methoxyflurane is not used in patients with impaired surfactant activity as such is found after severe traumatisation, head injury or in special preexisting pulmonary diseases. If this anesthetic is given to healthy individuals, the ventilatory pattern should include periodic sighs and prophylactic PEEP.

Animals↗
PubMed1975

[The influence of enflurane (ethrane) on surface activity of the lung (author's transl)].

Enflurane (Ethrane), a new inhalation anesthetic, was examined for possible surfactant alterating properties. To elucidate this question two groups of rabbits underwent investigation: the first group (5 animals) was mechanically ventilated with room air over a five hour period. In the second group (7 animals) for the same period Enflurane in clinical dosages was added the inspired gas. At the end of the procedure in neither group could signs of impaired lung surface activity be detected: All rabbits showed normal blood gas values, normal pressure volume diagrams and physiologic behaviour of lung extracts in the wilhelmy balance. We conclude first that artificial ventilation "per se" does not harm lung surfactant and second that Enfluran anesthesia is a good choice for outstanding long procedures as well as for patients with already impaired surface activity of the lung, because there seems to be little risk of aggravating the situation.

Animals↗