Biomedical subjects

E Lucchinetti

Publications and source records attributed to E Lucchinetti.

3 recordsLinked to original sources

PubMed1998

Substantial changes in arterial blood gases during thoracoscopic surgery can be missed by conventional intermittent laboratory blood gas analyses.

UNLABELLED: Substantial and clinically relevant changes in arterial blood gases are likely to occur during thoracoscopic surgery with one-lung ventilation (OLV). We hypothesized that they may be missed when using the conventional intermittent blood gas sampling practice. Therefore, during 30 thoracoscopic procedures with OLV, the sampling intervals between consecutive intermittent laboratory blood gas analyses (BGA) were evaluated with respect to changes of PaO2, PaCO2, and pHa ([H+]) using a continuous intraarterial blood gas monitoring system. Frequency and timing of BGA were based on the clinical judgment of 16 experienced anesthesiologists who were blinded to the continuously measured values. Extreme fluctuations of PaO2 (37-625 mm Hg), PaCO2 (27-56 mm Hg), and pHa (7.24-7.51) were observed by continuous blood gas monitoring. During 63% of all sampling intervals, PaO2 decreased >20% compared with the preceding BGA value, which remained undetected by intermittent analysis. In 10 patients with a continuously measured minimal PaO2 value < or = 60 mm Hg, the preceding BGA overestimated this minimal PaO2 by > 47%. Correspondingly, PaCO2 increases of > 10% were observed in 35% of all sampling intervals, and [H+] increases of > 10% were observed in 24% of all sampling intervals. Because these blood gas changes were not reliably detected by using noninvasive monitoring and their magnitude is not predictable during OLV, intermittent BGA with short sampling intervals is warranted. In critical cases, continuous blood gas monitoring may be helpful. IMPLICATIONS: The magnitude of blood gas changes during thoracoscopic surgery with one-lung ventilation is not predictable and not reliably detected by noninvasive monitoring. Using a continuous intraarterial blood gas monitoring device, we demonstrated that intermittent laboratory blood gas analysis with short sampling intervals is warranted to detect arterial hypoxemia.

Adolescent↗

PubMed1994

[Development and adaptation of tensile strength by bones in the extremities in response to physical training exemplified by the tibia].

Results from an in vivo assessment of the bending stiffness of human tibiae with a new method demonstrate that bone mineral measurements are not a suitable predictor to evaluate changes of mechanical properties of long bones. In a study on 559 male military recruits, the bone mineral at tibial shaft resulted in a mean increase of +1.8% during 15 weeks of exercise. The bending stiffness however increased about 25%. An additional test 24 months later on a sample indicated that the increase of bone mineral content was only due to the natural maturation of bone. The bending stiffness however, decreased by about 6% demonstrating the earlier training effect. No correlation between bone mineral and bending stiffness could be found neither in absolute values nor in difference between the three measurements. At the same time first results of a normative study on children (9 to 18 years old, male and female) and on women (up to 80 years old) are presented.

Adolescent↗

PubMed1993

[Cushioning versus stability].

Cushioning and stability are still key words for functionally constructed sport shoes. The goal of this investigation is to present and discuss the possibilities and limits of these shoe properties. Here, stability is not regarded as rigidity (like in a ski boot), but as a "dynamic stability" in the sense of functionality which supports the foot under load in such a manner that no unphysiological movements are provoked. Cushioning (in physics terminology: "damping") is defined to reduce and eliminate (kinetic) energy. When considering the impact peak in running, this peak can be reduced by using hard shoe soles with large heel flares. However, by doing that, large levers are introduced which produce an increased distance to decelerate the touchdown. This is basically the opposite of dynamic stability. Current shoe sole materials (homogeneous/isotropic) improve the "cushioning" but enhance the instability. New ways of shoe construction using more sophisticated anisotropic materials may lead out of this dichotomy.

Computer Simulation↗