Pain and symptom control for cancer patients at the University Hospital in Essen: integration of specialists' knowledge into routine work

At the University Hospital of Essen, supportive care for patients with cancer and other painful diseases is carried out by an interdisciplinary ambulant pain clinic supported by a pain conference with delegates from all departments involved in the care of cancer patients as permanent members. More than 600 in- and outpatients per year are treated by this institution. This model tends to integrate supportive care into the overall therapeutic concept and routine work and to improve education in this field by bedside teaching and training of local specialists in every department. Therefore, when hospitalization becomes inevitable it is realized within the department mainly concerned with the underlying disease, where the registrar and the physician belonging to the palliative care team work closely together. Scientific research in the field of palliative care, including supportive care, is a further concern of the pain clinic. Evaluation of the model shows that the concept has been realized within a decentralized and interdisciplinary setting; it must, of course, be borne in mind that the staff of the pain control clinic are deeply committed to their work. In conclusion, the way supportive care is realized in Essen can be recommended for large hospitals, and especially for medical schools.

Is the laser Doppler flow signal a measure of microcirculatory cell flux?

To assess oxygen transport as a function of hematocrit, microcirculatory red blood cell flux (microflux) was measured by laser Doppler flowmetry (LDF) in the isolated rat mesentery as well as in cat sartorius muscle. The hematocrit value was varied from 0.5 to 50% while the perfusion pressure ranged from about 2.7 to 13 kPa. Simultaneously macroflux which is the volume flow times the systemic hematocrit value was determined. The curves LDF versus pressure showed saturation at several hematocrit values conveying the impression of autoregulation of microflux. The macroflux curves, on the other hand, curved upward. To clarify whether this discrepancy had a physiological cause, pressure-microflux as well as pressure-macroflux curves were collected in a flow chamber model where regulatory effects are absent. In the model the same discrepancies between micro- and macroflux as in vivo were observed. These discrepancies are explained by maximum values in velocity of about 3 mm/s and in hematocrit value of less than or equal to 20% which the LDF can discern. The limit in velocity is explained by the low pass filter of 12 kHz of the LDF instrument, the limit in hematocrit measurement is probably caused by the light scattering properties of red blood cell suspensions. A complicated combination of effects appears to be responsible for the linearity of the LDF signal versus macroflux at normal hematocrit value.

A comparative study: perfusion of the micro- and macrocirculation as a function of the hematocrit value

The fluidity (the inverse of viscosity) of red blood cell (RBC) suspensions in vivo was estimated by means of microcirculatory measurements such as RBC flow velocity, micropressure in arterioles and venules, and vessel geometry, and by means of simultaneous macrocirculatory measurements such as volume flow and perfusion pressure in the whole organ. These in vivo data were compared to in vitro data obtained by viscometry. The experiments were performed on the isolated rat mesentery perfused with a nonaggregating and an aggregating suspension: Human RBC were either suspended in Ringer's or Ficoll 400 solution. The tissue was perfused at various perfusion pressures and hematocrit values. The microcirculatory perfusion was recorded by means of microscopy using a video TV system. Five major results have been identified: First, microfluidities calculated from velocity data in capillaries of the mesenteric membrane were almost identical to the fluidities calculated from macroflow data (volume flow rates and perfusion pressure in the whole organ). Second, in vivo fluidities of both suspensions decrease with increasing hematocrit value but seem to be independent of driving pressure between 4 and 10 kPa. Third, the fluidity of the Ficoll suspensions is lower than the fluidity of the Ringer's suspensions by the same ratio as the continuous phases. Fourth, the in vivo fluidities of the Ringer's suspensions and the Ficoll suspensions for hematocrit values from 20 to 70% and a range of wall shear stresses from 0.6 to 1 Pa were higher than those measured in vitro. Finally, it has been quantified that an increasing number of vessels became stagnant (that is packed by red blood cells) at high hematocrit values, low perfusion pressure, and increased aggregability of RBC.

Changes in intraconceptus pressure in the rabbit during days 7-10 of pregnancy

The present study established the magnitude of and temporal changes in the pressure within in situ rabbit conceptuses during early pregnancy. At the 7th, 8th, 9th, or 10th day post coitum (dpc), animals were anesthetized, and the number and dimensions of implantation sites were recorded. Conceptus pressure was measured by the servo-nulling method employing a glass micropipette. The mean number of sites was 6/cornu; spacing appeared normal. Implantation dome volume increased from 7 through 10 dpc: 0.2 +/- 0.03; 0.5 +/- 0.1; 1.6 +/- 0.2, and 2.7 +/- 0.9 cm3, respectively (Day 7 vs. 8, 9 and 10, p less than 0.01). Intraconceptus pressure declined between 7 and 10 dpc: 6.3 +/- 0.4; 5.7 +/- 0.4; 4.5 +/- 0.9, and 3.9 +/- 0.7 mm Hg, respectively (Day 7 vs. 10, p less than 0.05). Pressure fluctuated; the frequency of change in pressure varied between 7 and 8 dpc (4.2 +/- 3.0 to 2.3 +/- 3.5 peaks/min). The amplitude of fluctuation did not vary significantly between 7 and 10 dpc (2.6 +/- 0.3; 0.79 +/- 0.8 mm Hg, respectively). Simultaneous measurement of pressure within the conceptus and within the adjacent uterine lumen indicated that alterations in luminal pressure only occasionally influenced pressure within the conceptus. The decline in conceptus pressure suggests that the uterine wall becomes progressively more compliant as blastocyst cavity/yolk sac fluid accumulates within the conceptus. Conceptus expansion resulting from internal pressure may enhance conceptus-uterine metabolic exchange by facilitating apposition of conceptus-uterine surfaces and by increasing the ratio of conceptus surface to cytoplasmic mass.