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Biomedical subjects

K Koppenhagen

Publications and source records attributed to K Koppenhagen.

67 records · Page 4Linked to original sources
PubMed1976

Respiratory gas exchange and lung perfusion in man during and after head-out water immersion.

The respiratory gas exchange for O2, CO2, and CO has been studied in nine healthy male subjects before, during, and after head-out water immersion. Distribution of lung perfusion and ventilation were determined by quantitative double nuclide scintigraphy (131J and 99mTc) and by argon washout, respectively. The well-known decrease of PaO2 and increase of AaDO2 during immersion is accompanied by a decrease of the CO-transfer factor. Ventilation in relation to functional residual volume does not change significantly, whereas distribution of lung perfusion becomes more even, with an increase in the apical lung zones. Immediately after the end of immersion, PaO2 increases rapidly, exceeding the initial value under dry conditions. At the same time, lung perfusion is shifted markedly more towards the basal lung regions, exceeding the gravity-induced blood pooling in the erect subject under dry conditions. The observed changes tend to normalize within 2 min. The changes of respiratory gas exchange during and immediately after immersion can be explained by changes of the inequality of the ventilation-perfusion ratios.

Adult↗
PubMed1975

Water-vapor-independent inlet system for a respiratory mass spectrometer: application to experiments with a human centrifuge.

When using a two-stage inlet system in mass spectrometric analysis of permanent gases, changes of water-vapor partial pressure from inspiration to expiration considerably impede the measurements. With this type of gas inlet system, use of a mass spectrometer for measurements on a human centrifuge is rather limited. Introduction of a water-vapor - independent three-stage inlet system permits quantitative analysis of gas mixtures even if the water vapor pressure varies quickly with time. The expiratory oxygen and carbon dioxide partial pressure curves should exemplify that even under extreme acceleration conditions the three-stage system permits simultaneous and continuous mass spectrometric analysis of respiratory gases, with satisfactory response time and a simple experimental arrangement. The method described thus opens up new experimental possibilities for the investigation or respiratory gas exchange phenomena under acceleration conditions.

Adult↗
PubMed1975

Autonomous adenoma of the thyroid in infancy.

This is a report on two 10-year-old girls with a decompensated autonomous adenoma of the thyroid gland. Both girls were clinically euthyroid. In one girl there was no response of the thyrotropic cells of the anterior pituitary lobe to TRH stimulation for a short time during the first postoperative weeks. The diagnostic and therapeutic procedure in the case of nodular transformations in the thyroid area is discussed.

Adenoma↗
PubMedDate not supplied

Efficacy and safety of low molecular weight heparin, unfractionated heparin and warfarin for thrombo-embolism prophylaxis in orthopaedic surgery: a meta-analysis of randomised clinical trials.

UNLABELLED: The efficacy and safety of low molecular weight heparin (LMWH), unfractionated heparin (UFH) and warfarin for prophylaxis of thrombo-embolism in orthopaedic surgery were compared using meta-analysis techniques. Twenty-two studies were included, 2 of which compared LMWH to warfarin. The mean probabilities to develop deep-vein thrombosis (DVT), pulmonary embolism and major and minor bleeding using UFH were: 0.21 (95% confidence interval, CI: 0.18-0.24); 0.01 (95% CI: 0.01-0.02); 0.05 (95% CI: 0.03-0.07), and 0.19 (95% CI: 0.17-0.22), respectively. The relative risk (RR) of DVT for LMWH vs. UFH was 0.76 (95% CI: 0.60-0.91), p < 0.05 and for LMWH vs. warfarin 0.78 (95% CI: 0.69-0.87), p < 0.05. The RR of minor bleeding for LMWH vs. UFH was 0.76 (95% CI: 0.64-0.92), p < 0.05. The RR of minor bleeding for LMWH vs. warfarin was 3.28 (95% CI: 2.21-4.70), p < 0.05. CONCLUSION: in orthopaedic surgery, LMWH is significantly superior to both UFH and warfarin in the prevention of DVT and results in significantly less minor bleeding complications when compared to UFH, but significantly more minor bleeding when compared to warfarin.

Anticoagulants↗
PubMedDate not supplied

The effect of pentoxifylline ('Trental') on cerebral blood flow: a double-blind study.

A double-blind, placebo controlled crossover study was carried out in 20 geriatric patients with cerebrovascular insufficiency ot asses the effect of pentoxifylline on cerebral blood flow. Using 99m Tc cerebral scinitigraphy and a gamma comera/computer system, the pattern of blood flow in 5 brain areas was manitored after a single intravenous infusion of 200 mg pentoxifylline (10 ml) and after 10 ml saline solution. The results showed that, with the exception of one brain area, there was a statistically significant increase both in regional and hemispheric cerebral blood flow after pentoxifylline. It is of particular interst that global hemispheric blood flow, which gives an indication of total blood supply to the brain, showed approximately the same percentage increase on both sides with pentoxifylline.

Aged↗