[Adaptation to intermittent hypoxia-hyperoxia improves cognitive performance and exercise tolerance in elderly].

For improvements in exercise tolerance and cognitive function in geriatric patients Multimodal training programs (MTP) are used as combination of physiotherapy, occupational therapy and cardiovascular training. Intermittent Hypoxic-Hyperoxic Training (IHHT), a modified type of intermittent hypoxic training (IHT) is proposed to be included in MTP to elicit more pronounced beneficial effects in exercise tolerance and cognitive functions of geriatric patients likely by an additional pathway than a single MTP. Thirty four patients of the Geriatric Day Clinic aged between 64 and 92 years participated in the placebo controlled clinical trial. They were randomly assigned to receive MTP plus IHHT (experimental group - EG) or MTP plus placebo-breathing through a machine face mask (control group - CG) in a double blind fashion. Before and after the interventions course cognitive performance was assessed by the Dementia-Detection-Test (DemTect) and the Clock-Drawing-Test (CDT), and functional exercise capacity - by the total distance of 6-Minute-Walk-Test (6MWT). After IHHT combined with MTP cognitive performance (DemTect) increased significantly when compared to NG (+16,7 % vs. +0,39 %, p<0,001). The CDT indicated similar results with a significant increase in the EG while the score of the CG even decreased (+10,7 % vs. -8%, p=0,031). Concerning the functional exercise capacity, both groups improved the total distance in the 6MWT but with a significantly larger increase in the EG compared to the CG (+24,1 % vs. +10,8 %, p=0,021). In addition, there was a significant relationship between the changes of the 6MWT and the DemTect Scores and the CDT. IHHT contributed significantly to improvements in cognitive performance and exercise capacity in elderly performing MTP. IHHT sessions are considered to be easily applicable to and well tolerated by geriatric patients up to 92 years.

[Knowledge-based diagnosis and therapeutic recommendations with fuzzy-set theory methods in patients with acute lung failure (ARDS)]. / Wissensbasierte Diagnostik und Therapieempfehlung mit Methoden der Fuzzy-Set-Theorie bei Patienten mit akutem Lungenversagen (ARDS).

OBJECTIVE: Since the treatment of patients with severe ARDS using the extracorporal lung assist (ECLA) methods remains a cost intensive and speculative procedure, a knowledge based computer system should be created and evaluated in order to support clinical decisions. METHODS: The model was based on the fuzzy set theory and therefore able to give decisions between yes and no, that means that a criterion could also be fulfilled to 35% or 80% for example. The development of this computer program consists of two steps: first, the entry criteria for the ECLA therapy were established within a framework of an international evaluation of clinical data from 3 centres (Berlin, Marburg, Vienna). Here, inherent vagueness, uncertainty of the occurrence and limited availability of medical data are to be considered to establish a useful tool. Secondly, this was done by grouping and weighting of parameters by the system and the status of each patient or patient group was assigned by the percentage of fulfillment of the criterion. RESULTS: By using a mixed sample of patients from these three centres, the fulfillment of entry criteria according either to definitions of Berlin or to definition of Marburg was different (68% versus 36%). Other differences (36% vs. 22% and 68% vs. 60%) were found between the fuzzy based score and the crisp score which represents the usually performed method. CONCLUSIONS: This now preevaluated minimal data set to describe severe ARDS patients based on the fuzzy set theory may be useful to evaluate patients for ECLA therapy or for another controlled ARDS-therapy.

Colour-coded duplex sonography of preocclusive carotid stenoses.

OBJECTIVE: The accuracy of colour-coded duplex sonography (CCDS) for differentiating preocclusive stenoses from occlusions of the internal carotid artery (ICA) is a crucial point in non-invasive quantification of atherosclerotic lesions prior to carotid endarterectomy. METHODS: A total of 401 consecutive patients with CCDS followed by ICA arteriographies as gold standard was available for comparison. The entire number was divided into groups of <90%, 90-94%, preocclusive (95-99%) stenoses and occlusions. Sensitivity, specificity, and predictive value for distinguishing these groups were calculated using a contingency table. RESULTS: With CCDS we found a sensitivity of 88% and a specificity of 99% in 43 preocclusive ?95% stenoses. Similar findings were seen in 31 occlusions of the ICA (SE 87%, SP 99%). CCDS accurately differentiates the subgroups of severe carotid obstructions (90-94%, ?95% and occluded) shown by a predictive accuracy of 97, 96 and 93%. Carotid endarterectomies were performed in two of three angiographically occluded but sonographically preocclusive arteries. Intraoperatively preocclusive ICAs were seen in both cases. CONCLUSION: CCDS showed a high accuracy for differentiating preocclusive stenoses and occlusion of the ICA. Intraoperative findings indicated that angiography is not the absolute gold standard for preocclusive carotid disease in every case. Irregularities of the stenosis channel make it impossible to estimate the true area reduction in stenoses ?90%. The hemodynamic estimation of degree of stenosis by Doppler ultrasound may be closer to reality than angiographic measurement.

The knowledge model of MedFrame/CADIAG-IV.

The medical consultation system MedFrame/CADIAG-IV is a successor of the prior CADIAG projects. It is the result of a complete redesign to account for today's demands on state-of-the-art software. Its knowledge representation and inference process are based on fuzzy set theory and fuzzy logic. Fuzzy sets are used for conversions from measured numeric values and observational data into symbolic ones. Medical relationships between findings, diseases, and therapies, the rules, are represented by fuzzy relations, that express positive or negative associations. Findings, diseases, and therapies are organised in hierarchies.

[Color-coded duplex ultrasound in pre-occlusive stenoses of the internal carotid artery]. / Farbkodierte Duplexsonographie bei präokklusiven Stenosen der Arteria carotis interna.

In a prospective study the results of 238 consecutive ultrasound examinations of the carotid artery were correlated with angiography to test the reliability of colour coded duplex sonography in preocclusive carotid artery disease. This series was compared with a series of 611 vessels with angiographically controlled conventional duplex sonography. In 61 resp. 84 cases stenoses > or = 90% or occlusions of the internal carotid artery were found. The reliability of colour coded duplex sonography for the diagnosis of > or = 90% stenoses was extremely high (sensitivity and specificity 98%), as well as in preocclusive, > 95% stenoses (100% and 98%), and for the diagnosis of occlusion, after exclusion of angiographic false positive diagnosis of occlusion (95% and 99%). Statistically colour coded flow imaging failed to increase significantly the high diagnostic sensitivity or specificity of conventional duplex sonography, especially in preocclusive carotid artery disease. However, the remarkable increase in frequency of the diagnosis preocclusive stenosis with the introduction of colour coded Duplex Sonography probably reflects a higher sensitivity of this method. In addition the direct comparison of both ultrasound techniques showed a better image of the vessel wall abnormalities and the residual lumen with colour coded duplex sonography.