[Organization of pain therapy in surgery--comparison of acute pain service and alternative concepts]. / Organisation der Schmerztherapie in der Chirurgie. Akutschmerzdienst und alternative Möglichkeiten im Vergleich.

An acute pain service done by surgeons is one possibility for organizing pain therapy in surgical wards. To do this successfully, some preconditions must be kept in mind, such as 24-h presence, an integrated system of documentation, and teamwork between medical and nursing staff. Comparison of differently structured pain therapy in three different hospitals (with and without acute pain service) showed high levels of patient satisfaction with the pain therapies in all three hospitals. One of the preconditions for effective pain therapy in surgery is to formulate a concept which takes into account the specific situation of each hospital.

[Efficacy of an Acute Pain Service--a controlled comparative study of hospitals]. / Effizienz eines Akuten Schmerzdienstes--Eine kontrollierte Krankenhausvergleichsstudie.

The efficacy of an acute pain service was prospectively evaluated on elective abdominal operations by comparing two surgical departments including a total of 498 patients. The patients of the clinic with an acute pain service reported less pain (at rest and in movement) pre- and postoperatively and received more analgetics. They had more appetite, lower sleep requirements and more independence. The patients' overall satisfaction was greater in the clinic with an acute pain service.

Barriers in cardiac substrate supply.

The capillary wall, due to its diffusional resistance, causes concentration differences between the vascular space and the interstitial space for substances which are released or taken up by the heart. Estimation of capillary transfer and interstitial concentration in isolated hearts, however, indicates a variable diffusional resistance, which in the case of glucose results from an insulin dependent transfer mechanism and in the case of lactate from a dependence of lactate transfer on lactate concentration or direction of transfer. Due to the unpredictable interstitial concentration investigation of sarcolemmal transfer appears to be possible at present only with isolated cardiac myocytes. Sarcolemmal transfer was studied for glucose and lactate. Recent investigations of lactate transfer revealed saturation kinetics, dependence on pyruvate (inhibition at low lactate concentration and enhancement at high lactate concentration) and dependence on pH (linear increase with lowered pH [8.0 to 6.7]).

Effects of Ca2+ deficiency, collagenase, and mechanical dispersion on the ultrastructure of cardiac myocytes of adult rats.

A new perfusion medium for isolating cardiac myocytes from adult rats was developed, thereby yielding numerous viable cells with few morphological changes. The main factors in the isolation procedure are Ca2+ deficiency, collagenase, and mechanical dispersion. Their effects on the ultrastructure of cardiac myocytes were separately tested. In isolated hearts, perfusion with a medium containing a physiological Ca2+ concentration (2.5 mM, controls) preserved the cellular fine structure well, whereas perfusion with a medium containing 2.5 mM Ca2+ plus 0.05% collagenase caused swelling and disruption of most cells. Perfusion with a Ca2+-deficient medium followed by a medium with a low Ca2+ concentration (25 microM) either containing or lacking collagenase resulted in widening of the T-tubules, reduced electron density of the external lamina and occasional separation, or even dissolution of this layer. Some cells were damaged and hypercontracted. These appeared more numerous in suspensions, that means after mechanical dispersion of the myocardium. However, most of the isolated cells were regularly shaped (up to 30-60 min as shown in another study) and their ultrastructure was only slightly altered. This corresponds to an adequate preservation of the cell membranes proven in earlier membrane transfer studies.