Tonic descending inhibition affects intensity coding of nociceptive responses of spinal dorsal horn neurones in the cat.

The supraspinal inhibitory control of lumbar spinal dorsal horn neurones was investigated in N2O-anaesthetized cats by reversibly blocking conduction in the spinal cord. Dorsal horn neurones selected for this study had convergent input from myelinated (A-) and unmyelinated (C-) fibres in the posterior tibial and/or superficial peroneal nerves of the hind limb. Virtually all of them could also be excited by noxious heating of the skin of the footpad region and by low intensity mechanical stimulation of the foot. Variation of the temperature of noxious radiant skin heating (40-56 degrees C, 10 sec in duration) resulted in graded responses of the neurones. The stimulus-response functions (SRF) were monotonic; in the majority of 32 cases they were linear. Neurones could be classified according to their maximum discharge frequency in response to skin heating into 22 weakly sensitive units (responses below 100 Hz at 50 degrees C) and 10 highly sensitive units (above 100 Hz). Responses outlasted the period of skin heating by seconds to minutes. A reversible conduction block of spinal axons by cooling a 15 mm cord segment (L1) with a thermode at 0 degrees C affected the responsiveness of the dorsal horn neurones in 12 of 15 cases. The maximum discharge frequency to a certain temperature of skin heating was increased during the spinal block. The duration of heat-evoked discharges was either not changed or increased during the spinal block. The SRF were reversibly displaced during the spinal blockade to higher discharge frequencies and lower threshold temperatures of skin heating. In 8 of 12 cases the change in the SRF was a nearly parallel shift, whereas in 4 units the increase of responsiveness had a complex effect upon the SRF. The decrease in the threshold to skin heating ranged up to 4.5 degrees C; the mean decrease was 2 degrees C. It is confirmed that in anaesthetized cats, nociceptive spinal neurones are subject to a tonically active descending inhibition, which is interrupted by local spinal cooling. The effect of the spinal block on the SRF of the neurones suggests that this tonic inhibition is similar to that produced by electrical stimulation in the lateral reticular formation of the brain-stem.

[Somatostatin in the treatment of acute haemorrhage from a duodenal ulcer (author's transl)]. / Somatostatin in der Behandlung der akuten Ulkusblutung.

A massive haemorrhage from a duodenal ulcer verified on endoscopy in a 21 year-old patient was stopped by a 62--hour infusion of somatostatin at a dosage of 250 microgram/hour. Suppression of gastric secretion is probably more important than the reduction in splanchnic blood flow with regard to the mechanism of action of this drug. No side effects were observed.

[Inhibition in the spinal cord: a neuronal mechanism of hypalgesia produced by acupuncture (author's transl)]. / Hemmung im Rückenmark, ein neurophysiologischer Wirkungsmechanismus bei der Hypalgesie durch Stimulationsakupunktur.

Central nervous system mechanisms of nociception and pain were studied electrophysiologically in the spinal cord of cats. A great proportion of dorsal horn neurons respond to noxious skin stimuli, for instance to heating to 50 degrees C; such stimuli predominantly activate afferent C fibres. These spinal neurons participate in the transmission of nociceptive information to the brain. The heat-evoked discharges of dorsal horn neurons are effectively inhibited by repetitive electrical stimulation of large;, low-threshold cutaneous A fibres. The inhibition reaches its maximum effect after several minutes of nerve stimulation, and declines at a slow rate after the end of stimulation. This long-term suppression is considered to be a neuronal mechanism underlying hypalgesia produced in man e.g. by acupuncture and by transcutaneous nerve stimulation.

[A case report of caesarian section carred out under electroanasthesia (authors transl)]. / Fallbericht einer Sectio caesarea mit Hilfe der Elektroanästhesie

The case is reported of a 19 year-old patient in whom Caesarian section was successfully performed under combined method of anaesthesia. Square waves, which consist of high frequency impulses were transmitted to the cerebrum, and in addition, a 50:50 nitrous oxide and oxygen gas mixture was administered to the patient. The intraoperative condition of the patient was satisfactory. No reactions to pain were seen, as judged from constant observation of the blood pressure, pulse rate, colour of the face, pupils and the condition of the body extremities.

[Algesimetric measurement of the effect of cerebral electrotherapy on the pain threshold (author's transl)]. / Agesimetrische Messungen von Veränderungen der Schmerzschwelle unter zerebraler Elektrotherapie (CET, Elektroanästhesie)

The effect of cerebral electrotherapy (CET) on the pain threshold was investigated in 3 test persons, on 5 points of the neck of these persons. Altogether 1200 algesimetric measurements were performed. The statistical evaluation showed a significant tedency (p less than 0.01) towards an elevation of the pain threshold by CET.

[Assessment of the cardiac output by impedance cardiography (differential rheography) to give optimum continuous positive pressure ventilation (author's transl)]. / Beurteilung des Herzzeitvolumens durch Impedanzmessung (Differentialrheographie) zur Optimierung der kontinuierlichen Uberdruckbeatmung (CPPV).

It is very important to know the cardiac output in artificial positive pressure ventilation for the determination of the exact dosage of dopamine and the endexpiratory pressure. Invasive monitoring of the cardiac output is not suitable for routine bedside use. In our study we looked into the question of whether the dosage of dopamine in continuous positive pressure ventilation could be controlled by impedance determination. Differential rheography, as described by Kaindl, Polzer, and Schuhfried, was used in the study. Relative changes in cardiac output after dopamine administration are shown with sufficient accuracy using the above-mentioned method.

[The influence of acupuncture analgesia on the sensation and feeling of pain and the autonomic state of the organism (author's transl)]. / Beeinflussung der Schmerzempfindung, des Schmerzgefühls und der vegetativen Lage des Organismus unter Akupunktur-"Analgesie"

This study reports the effect of acupuncture on the sensation of pain, feeling of pain and on the autonomic state of the organism. In order to elucidate the problem physiological and psychological parameters were employed. It was observed that the insertion of the needles with electrical stimulation raised the pain threshold. The rise occurred whether a classical acupuncture point or a placebo acupuncture point was used. When the pain was assessed subjectively, it was found that the needling of a classical acupuncture point favourably influenced the experience of pain. Furthermore, persons in whom acupuncture worked well were characterized by a low subjective and objective pain threshold, a slow pulse rate and a high anxiety score.

[Control of respiratory therapy by means of rheography (author's transl)]. / Die Uberwachung der Atemtherapie mittels der Rheographie.

Rheography measures changes in electrical conductivity. In measurements taken at the thorax it was appeared that the changes in conductivity caused by breathing are superimposed by the changes caused by circulatory factors and exceed them in amplitude quite far. This makes the expansion of rheography for electrical respiration control possible. The changes in electrical conductivity are explained by inspiration into the alveoles, by the increase in the distance of the electrodes on thoracic expansion, and by the change in the intrathoracic blood volume. When using respiratory therapy the physiotherapist must pay great attention how the patient reacts to respiratory therapy and whether he is adapted correctly to the mechanical respiratory support devices. The method of "rheospirography" was tested as to whether it allows an objective, direct evaluation of the interplay between respiratory therapy and patient. The method appears to be able to control respiratory therapeutic measures as it allows an evaluation of the respiratory type, the regional ventilation, and the adaption of the patient to the device.

Endorphins: mechanism of acupuncture analgesia.

Discharges were recorded from spinal dorsal horn neurons in response to noxious skin heating (50 degrees C) in anesthetized cats. Repetitive electrical stimulation of the superficial peroneal (SP) and posterior tibial (PT) nerves inhibited these nociceptive discharges as well as systemic administration of met-enkephalinamide (synthetic endorphin). The inhibitory effects of electro-stimulation as well as administration of synthetic endorphin were partially but significantly antagonized by naloxone, thus arguing in favor of endogenous morphine release as the basis for the mechanism of acupuncture analgesia. However, non-responding neuronal units to the administration of enkephalin were also observed in the present study. These non-responding units may explain why acupuncture is not effective in some individuals.

Disinfection for infection prevention over the course of time.

In recent years and decades increasingly more emphasis has been placed on alcohol-based solutions for hygienic and surgical hand disinfection. Traditional handwashing with soap and water has been largely replaced in the everyday clinical setting, as has the use of disinfectant soap-based solutions for surgical hand disinfection. It has been possible in recent years to reduce the exposure time for alcohol-based hand disinfection in surgery from 5 to 3 minutes, and there are plans to reduce this even further. The growing awareness of the tolerability issues has also given rise to favorable developments here. There have also been dramatic changes in preoperative skin disinfection. The non-alcoholic solutions with a slow onset of action (e.g. iodophors) have been virtually replaced by alcohol-based solutions of demonstrated efficacy. Non-alcoholic solutions continue to be used for disinfection of mucous membranes, but iodine-based products are being phased out here. The term "instrument disinfection" has been largely supplanted now by the expression "instrument reprocessing or medical device decontamination" (which is also underpinned by legislation) and it takes account of the trend towards thermal disinfection. Meticulous cleaning is thus an indispensable precondition for sterilization, which normally follows disinfection. The greatest lack of consensus at European level relates to surface disinfection. Routine, parallel cleaning and disinfection of all surfaces close to and remote from the patient is being increasingly replaced by selective disinfection, whenever warranted, of surfaces close to the patient. The problem here is that medical personnel continue to view cleaning and disinfection as interchangeable tasks. This situation is further compounded by the fact that hospitals are finding it increasingly more difficult to assure adequately successful cleaning and disinfection outcomes. To ensure effective infection control, cleaning and disinfection of surfaces in special situations must also be assured whenever warranted outside the regular working hours. Disinfection and decontamination of highly complex medical devices that pose special challenges (heat-sensitive devices with an intricate design and, correspondingly, with surfaces that are difficult to access, e.g. flexible endoscopes) will present the main challenge in the future. There is still much to be accomplished here to assure the hygienic safety of the patient.

[3-years' domiciliary respirator therapy in idiopathic hypoventilation syndrome (ondine's curse syndrome) (author's transl)]. / Drei Jahre Heimrespiratotortherapie bei idiopathischem Hypoventilationssyndrom *Undines Fluch-Syndrome).

A 67 years old patient with a tracheostomy and cribral cannula on account of severe idiopathic hypoventilation syndrome was discharged from the intensive care unit having been supplied with a respirator (MK 8-Bird) and compressor by his health insurance. The domiciliary respirator therapy was continued for more than 3 years. The disorder manifested itself initially in severe hypoventilation during sleep, acute hypoxaemia, hypercapnia and respiratory acidosis. The patient himself and his family took on the adjustment and maintenance of the respirator, having being appropriately trained before his discharge from hospital. The treatment succeeded for over 3 years in maintaining an acceptable quality of life for the patient.

[PC-based computer monitoring in an intensive care unit]. / Computerüberwachung auf PC-Basis für eine Intensivstation.

The lack of direct communication with the intensive care patient means the medical staff have to try to achieve a realistic picture of the condition of the patient from numerous pieces of detailed information fitted together something like a jigsaw. The immense amount of data thus gained means an overall interpretation of the many individual data would be hardly imaginable without the use of a computer. PC networks in conjunction with a high-level language provide an ideal basis for building up a background monitoring system that can be used at the bedside. Simple PC-ATs and software developed in house in Turbo-Pascal have enabled us to realize a useful and very economical computer-aided background monitoring system. Any online and offline data important for an operative critical care unit can be collected, documented, displayed and processed in secondary parameters.

[Modification of patients positions in operation table during regional anaesthesia (author's transl)]. / Modifikationen der Lagerung bei Patienten unter Regionalanästhesie (Plexus-axillaris-Blockade).

The comfort was improved by better positioning on the operating table in six patients undergoing extensive hand surgery with axillary plexus block. Opposite to that we could show in 16 similar cases with traditional position during surgery some pain, chills and discomfort despite optimal block technique.

[Pain relief in childbirth; an analysis of the analgesic effects of transcutaneous nerve stimulation (TNS), pethidine and placebos (author's transl)]. / Der Wehenschmerz während der Geburt. Zur Analyse der analgetischen Wirkung der transkutanen Nervenstimulation (TNS) im Vergleich mit Pethidin und Plazebos.

The analgesic affects of TNS, pethidine and placebos on labour pain were studied in 30 parturient women during the first stage of labour. 10 had TNS paravertebrally in the region of the afferent nerves at Th 10-Th 12; one group of 5 had unspecific (wrong) TNS; in another group of five no current was applied (placebo); five women were given 50 mg of pethidine intravenously; five patients acted as a control group. To assess the analgesic effects the women were asked to estimate the intensity of pain (grades 1-6) over a period of 70 minutes. There was no significant difference between the placebo, unspecific TNS and control groups as regarded the increase in pain during the test period. Patients who had received pethidine and those who had been given TNS at the site of the afferent nerves transmitting impulses from the uterus experienced considerable relief of pain. The differences were highly significant. The observations prove the genuine analgesic action of TNS. The use of this technique in obstetrics is discussed.

[Effect of arm splinting on the duration and possibility of monitoring invasive long-term pressure determination of the radial artery]. / Einfluss der Armschienung auf Verweildauer und Monitierbarkeit bei blutiger arterieller Langzeitdruckmessung über die A. radialis.

A special splint technique, which can improve continuous intraarterial blood pressure monitoring via the a. radialis is reported. This method could be applied successfully in 41 patients of the ICU up to 27 days. Cannulating the contralateral side because of catheter's dysfunction was necessary only in 6 patients. These observations could be seen in contrast to our results, using a conventional splint system, applied in 12 patients for comparison (maximal duration of catheter's placement: 9 days). Our experiences, using this special splint method of arm fixation, lead to the recommendation to use our method routinely in long-term monitored patients, with respect to a longer duration of catheter's intravasal placement, the possibility of undisturbed monitoring and a simple clinical handling.