Directed, Elliptic, and Higher Order Flow Harmonics of Protons, Deuterons, and Tritons in Au+Au Collisions at sqrt[s_{NN}]=2.4 GeV.

Flow coefficients v_{n} of the orders n=1-6 are measured with the High-Acceptance DiElectron Spectrometer (HADES) at GSI for protons, deuterons, and tritons as a function of centrality, transverse momentum, and rapidity in Au+Au collisions at sqrt[s_{NN}]=2.4 GeV. Combining the information from the flow coefficients of all orders allows us to construct for the first time, at collision energies of a few GeV, a multidifferential picture of the angular emission pattern of these particles. It reflects the complicated interplay between the effect of the central fireball pressure on the emission of particles and their subsequent interaction with spectator matter. The high precision information on higher order flow coefficients is a major step forward in constraining the equation of state of dense baryonic matter.

Strong Absorption of Hadrons with Hidden and Open Strangeness in Nuclear Matter.

We present the first observation of K^{-} and ϕ absorption within nuclear matter by means of π^{-}-induced reactions on C and W targets at an incident beam momentum of 1.7 GeV/c studied with HADES at SIS18/GSI. The double ratio (K^{-}/K^{+})_{W}/(K^{-}/K^{+})_{C} is found to be 0.319±0.009(stat)_{-0.012}^{+0.014}(syst) indicating a larger absorption of K^{-} in heavier targets as compared to lighter ones. The measured ϕ/K^{-} ratios in π^{-}+C and π^{-}+W reactions within the HADES acceptance are found to be equal to 0.55±0.04(stat)_{-0.07}^{+0.06}(syst) and to 0.63±0.06(stat)_{-0.11}^{+0.11}(syst), respectively. The similar ratios measured in the two different reactions demonstrate for the first time experimentally that the dynamics of the ϕ meson in nuclear medium is strongly coupled to the K^{-} dynamics. The large difference in the ϕ production off C and W nuclei is discussed in terms of a strong ϕN in-medium coupling. These results are relevant for the description of heavy-ion collisions and the structure of neutron stars.

Subthreshold Ξ

Results on the production of the double strange cascade hyperon Ξ^{-} are reported for collisions of p(3.5 GeV)+Nb, studied with the High Acceptance Di-Electron Spectrometer (HADES) at SIS18 at GSI Helmholtzzentrum for Heavy-Ion Research, Darmstadt. For the first time, subthreshold Ξ^{-} production is observed in proton-nucleus interactions. Assuming a Ξ^{-} phase-space distribution similar to that of Λ hyperons, the production probability amounts to P_{Ξ^{-}}=[2.0±0.4(stat)±0.3(norm)±0.6(syst)]×10^{-4} resulting in a Ξ^{-}/(Λ+Σ^{0}) ratio of P_{Ξ^{-}}/P_{Λ+Σ^{0}}=[1.2±0.3(stat)±0.4(syst)]×10^{-2}. Available model predictions are significantly lower than the measured Ξ^{-} yield.

[Longitudinal distribution of pulmonary vascular resistance in patients with acute respiratory insufficiency]. / Longitudinale Verteilung des pulmonalen Gefässwiderstands bei Patienten mit akuter respiratorischer Insuffizienz.

Effective pulmonary capillary pressure (Pc) is a major factor determining transvascular fluid filtration in the lung. It may easily be estimated from the pressure decay after rapid pulmonary artery occlusion. If Pc is known, the longitudinal distribution of pulmonary vascular resistance (PVR) can be evaluated. The present study was performed to address the following questions: (a) whether the severity of acute lung injury influences Pc and the longitudinal distribution of PVR; and (b) whether pulmonary artery occlusion (PAOP) or wedge pressure represents effective Pc during acute respiratory failure. PATIENTS AND METHODS. The investigation was performed in 45 mechanically ventilated patients. According to Murray's criteria 13 patients showed no lung injury, 19 had mild to moderate lung injury, and 13 had severe lung injury (adult respiratory distress syndrome, ARDS). As described by Holloway, effective Pc was evaluated from the pressure decay after rapid occlusion of the pulmonary artery (Figs. 1 and 2). The precapillary pressure gradient was determined as the difference between mean pulmonary artery pressure and Pc, the postcapillary pressure gradient as the difference between Pc and PAOP. Three measurements were performed and Pc determined as their mean value. The Kruskal-Wallis test and Mann-Whitney U test were performed to check statistically significant differences between groups. A Bonferroni correction was performed for multiple testing; P < 0.05 was accepted. RESULTS. Effective Pc was significantly different between patients with severe lung injury (20 +/- 3 mm Hg) and patients with mild to moderate lung injury (16 +/- 3 mm Hg), and between the latter group and patients without lung injury (12 +/- 3 mm Hg). The postcapillary pressure gradient and the relative amount of pulmonary venous vascular resistance, as well, were significantly influenced by the severity of the lung injury. In patients with ARDS the postcapillary pressure gradient was 4 +/- 1 mm Hg, whereas in patients with mild to moderate and without lung injury the postcapillary pressure gradients were 3 +/- 1 mm Hg and 2 +/- 1 mm Hg, respectively. Two ARDS patients had a postcapillary pressure gradient of 7 mm Hg (Pc 22 mm Hg and 19 mm Hg, PAOP 15 mm Hg and 12 mm Hg). One patient with severe lung injury had a postcapillary pressure gradient of 9 mm Hg (Pc 22 mm Hg, PAOP 13 mm Hg). In patients with severe lung injury 28 +/- 7% of the PVR was located in the postcapillary vascular system, whereas in patients with mild to moderate and without lung injury 22 +/- 7% and 16 +/- 6% of PVR was located in the pulmonary venous system. CONCLUSIONS. The longitudinal distribution of PVR is influenced by the severity of lung injury. PAOP, therefore, may not represent changes in Pc in patients with acute respiratory failure. The routine use of Pc measurement, however, can not be recommended until it has proven more useful than determination of PAOP when managing critically ill patients.

Capnometry for continuous postoperative monitoring of nonintubated, spontaneously breathing patients.

We continuously monitored spontaneous respiration after extubation by end-tidal CO2 tension (PETCO2) in 19 patients aged 20 to 72 years who had undergone major operations. The respiratory gas was sampled from the nasopharynx via a special nasal catheter and analyzed by a side-stream analyzer. In each case, optimal placement of the nasal catheter was determined by CO2 waveform and the capnograms were recorded for waveform analysis and trend monitoring. PETCO2 was compared with arterial CO2 tension (PaCO2) two to four times during the 2- to 19-hour observation periods by simultaneous measurements. For 65 simultaneous measurements, mean PETCO2 was 38.9 +/- 5.7 mm Hg (range, 26.3 to 48.3 mm Hg) and mean PaCO2 was 38.9 +/- 5.7 mm Hg (range, 26.8 to 46.0 mm Hg; r = 0.82; p less than 0.01). While the mean values for PETCO2 and PaCO2 were similar, several patients had large differences for PaCO2 to PETCO2. The differences of the individual patients did not differ significantly between the various times of measurement. We conclude that this form of capnometry is well suited for continuous, noninvasive monitoring of respiration in nonintubated, spontaneously breathing patients.

[Thoughts on alarm processing in intensive care medicine and anesthesia monitoring]. / Uberlegungen zur Alarmgebung in der Intensivmedizin und in der Narkoseüberwachung.

The experiences in alarm processing gained during computerised arrhythmia detection are transferred to the field of intensive care and anaesthesia, and are developed further. Here, the number of considered alarms has to be held as low as possible because there are many more different parameters and devices that can cause an alarm. Within the considered alarm, the number of false alarms must also be minimized. We tried to develop a methodology of alarm processing. Great effort has been spent on a uniform and effective notification, resetting, and documentation of alarms. As a means for alarm notification, acoustical devices with different sounds, lamps with different colours, alphanumeric and graphical screen displays are discussed. The manner of resetting (true/false) determines the subsequent alarm path. Besides special alarm history reports, documentation must connect alarm events with the normal patient records.

[The "trend magnifier"--a methodological tool for patient monitoring]. / Die "Trendlupe"--ein methodisches Hilfsmittel für die Patientenüberwachung.

In different fields of patient monitoring there is an increasing knowledge about the clinical importance of variations of short-term patterns in the courses of vital parameters. They can be used as diagnostic hints and warning signs as well as means for therapy control. This paper first gives a critical survey of methods suitable to meet the resulting requirements in the operation theater and the postoperative intensive care unit. Then it presents a methodological tool which gives improved possibilities for detecting and analyzing meaningful patterns. Minicomputers or microcomputers are used to sample and to display both the primary signals and the courses of vital parameters (courses of extracted features) in three steps: The first step corresponds to the trend registration in conventional monitoring systems. The vital parameters are registered with sampling intervals between 10 and 30 seconds, and are held for the whole staying period of the patient. In the second step the same parameters are registered for a limited time span with sampling intervals in the order of a beat-to-beat registration. In the third step the primary signals are registered for a certain time span (in a ringbuffer). The sampling interval depends on the individual signal. It should be in the order of 10 ms. After having detected an interesting event, it can be located and studied in more detail by using the second- and third-step-display. From each display, a hardcopy on a multi-color plotter may be produced to overcome the display limitations of the CRT and to obtain legal documents.

Influence of parenteral fat administration on the pulmonary vascular system in man.

In 16 patients with multiple injuries the effect of parenteral administration of a fat emulsion on the pulmonary vascular system has been studied. Using the Hewlett Packard 5600 A Intensive Care System, which allows vital parameters to be sampled at a rate of two values per min, pulmonary artery pressure (PAP) was monitored before, during, and after the administration of Lipofundin S 20% (0.24 g/kg/h). In addition right ventricular stroke work index (RVSWI), alveolar-arterial oxygen difference (A-aDO2) and pulmonary shunt (Qs/Qt) were calculated. The results indicate that there are no changes of the PAP, the RVSWI, and the A-aDO2 during the period of observation.

[Computerized cardiac rhythm and heart analysis in children with mitral valve prolapse (author's transl)]. / Rechnergestützte Herzrhythmus- und Frequenzanalyse bei Kindern mit Mitralklappenprolaps.

Twenty-nine children with echocardiographically-proven mitral valve prolapse (MVP) were studied by means of exercise-ECG testing, and continuous ECG monitoring. ECG's were stored on tape and compared with those of 20 healthy children. The frequency of supra- and ventricular premature beats (VPB) and the response of heart rate and RR intervals over the length of time ("tachogram") were graphed and analyzed by various algorithms. Of the children with MVP, one required treatment for his arrhythmia. A total of 16 children with MVP ( = 55%) had various rhythm disturbances. VPB's were observed in one child in the routine ECG, in four children during exercise testing, and in nine only during continuous ECG monitoring, whereas only 9% of the healthy children were found to display VPB's. Differences could also be seen in the tachogram readings: 22 ( = 76%) MVP children were characterized by a wide variation of RR intervals, suggesting a pronounced sympathetic reactivity, twelve ( = 60%) healthy and six ( = 23%) MVP children showed a narrow, oscillating tachogram trace. Although the syndrome is already present in childhood, it must be seen as progredient, manifesting itself in the frequency and gravity of arrhythmias.

[Computer aid in pediatric intensive care (author's transl)]. / Intensivüberwachung in der Pädiatrie mit Hilfe eines Rechnersystems.

The application of computerized intensive care in pediatrics is described. After adaption of commercial software and the development of several processing units, it was possible to control the circulatory and pulmonary function, reliably and continuously almost only by noninvasive methods. The graphical drawing of the trend of the controlled vital parameters will give better informations about the patients condition than the indication or registration of the momentary values. Moreover typical trend patterns of the measured parameters are hereby recognizable, so that critical situations will be detected, treated and - if possible - abolished earlier than in the past.

[Haemodynamics of blood supply to the pulmonary or body circulation via a patent ductus arteriosus in infants (author's transl)]. / Zur Hämodynamik bei Versorgung des Lungen- oder Köperkreislaufes über einen Ductus arteriosus im Säuglingsalter.

To control the cardiopulmonary functioning of high risk newborn with congenital heart defects the authors apply computergenerated recording of vital parameters predominantly measured by non-invasive methods. It was found that periodic variations of the arterial partial oxygen pressure occur with occlusion of the outflow from both the right and the left ventricle, associated with patent ductus arteriosus. The authors interpret these periodic variations as intermittent contractions of the arterial duct. The pathophysiology of this phenomenon is discussed.

[Coronary flow measurements with cine densitometry. II. Quantitative determinations of flow velocities and flow volumes through severe coronary stenoses during rest (author's transl)]. / Koronare Flussmessung mit der Cinedensitometrie. II. Quantitative Bestimmung von Stromgeschwindigkeiten und Durchflussmengen an hochgradigen Koronarstenosen unter truhebedingungen.

The normal flow values through healthy or moderately narrowed coronary arteries, which had been determined by a new method of cine radiography, together with a computer, were published in this Journal in 1976. In the present paper we report the results of further studies of flow velocity and flow volume through high-grade coronary artery stenosis of severity III and III--IV. Compared with the results obtained on normal and mildly stenosed arteries, measurements at rest through severely stenosed coronaries showed an almost constant flow. The first results on aorto-coronary vein graft measurement are described.

[Coronary flow measurements, using cine densitometry. Results using a multiple detector method. I. Normal flow values in healthy and stenosed coronary arteries during rest (author's transl)]. / Koronare Flussmessungen mit der Cinedensitometrie Ergebnisse mit dem Mehrfachdetektor-Messverfahren: I. Normalwerte der Durchblutung an gesunden und stenosierten Herzkranzefässen in körperlicher Ruhe

Coronary blood flow was measured by a cine densitometric method using a newly developed system incorporating computer data analysis. The first results concerning front and wave velocity of a selectively injected contrast bolus are reported. Average absolute flow volumes in the right coronary artery are 114 ml. per minute, in the left coronary artery, 88 ml per minute (RIVA = 52 ml/min., RC = ml/min.). There is good agreement with the results of dye dilution and isotope wash out techniques, but the latter are more complicated and less easily reproduced and therefore less suitable for routine use. The results are critically evaluated.

[Reproducible and congruent radiographs for the study of bone structure]. / Herstellung von reproduzierbaren und deckungsgleichen Röntgenbildern bei Knochenstrukturuntersuchungen

Radiograms that are reproducible and are as identical as possible are an absolute prerequisite for objective early diagnosis of the smallest changes in the bone structure. Changes that are no longer visible to the naked eye, are recorded by photometry and can be represented objectively by computerized evaluation. It is the object of this study to develop a method for taking roentgenograms with films generally used in the dental office, which allows to always the area always to be radiographed reproducibly. The x-ray machine is described and tested on four patients. The radiograms are photometrically scanned and entered into a computer in order to check the location of the radiograph. The results show that with our method it is possible to take identical radiograms at different times.