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Intravenous regional anesthesia.Short duration hand operations.Open wounds, lengthy operations, local infections, polyneuropathy, Raynaud syndrome, allergy to local anesthetics.Insertion of an intravenous cannula, attachment of a double lumen cuff, Esmarch's tourniquet, injection of the local anesthetic, stepwise pumping up the tourniquet, surgery, stepwise removal of the tourniquet.Postoperative monitoring of the patient after the end of anesthesia.Over a time period of 2 years (January 2017-December 2018) 90 operations of the hand were carried out with the patient under intravenous regional anesthesia (IVRA). The average age of the patients was 61 years. After surgery the patients were questioned according to the criteria of the quality of recovery‑9 score according to Myles in the German version of Eberhard et al. (2002). The tourniquet could be removed on average 29 min after surgery. No intraoperative or postoperative complications occurred. Therefore, the IVRA represents a reliable and simple form of anesthesia especially for surgery of the hand.

Pharmacists are an integral factor in palliative medical care, especially in the context of specialised outpatient palliative care (in Germany „SAPV“). As part of a multi professional team, pharmacists take care of patients especially in complex supply situations. The drug therapy is always checked for side-effects and interactions, and the medication is adjusted to application methods which are still possible (e. g. subcutaneous administration or administration via gastro-intestinal probes). A 24/7 supply of urgently needed medicines needs to be ensured and clinical nutrition must be suited to the real needs of the patient. Prompt aseptic manufacturing of analgesic pumps and the supply of medical devices is a priority of regional specialised pharmacies, whilst the basic support can be provided by all pharmacies who wish to engage in this ethically demanding field.

Pancuronium(bromide) is used because of its relaxing effect on striated muscles and usually requires artificial respiration. A 52-year-old woman suffered from long-standing "generalized dystonia", which had become resistant to conventional therapy. Therefore, an anesthetist established a permanent medication scheme with pancuronium using a PCA pump. This pump had been controlled by the patient herself ensuring an acceptable quality of life with broad personal autonomy. Finally, the woman was found dead in her flat by a member of a home nursing service. The infusion hose showed a fixed knot and further blocking by a clamp. The autopsy findings were non-specific, except for the presence of opioid tablets in the colon. Toxicological analyses showed 72ng/ml pancuronium and 21 ng/ml oxycodone (therapeutic) in the femoral venous blood. The range of published pancuronium levels varies from approx. 80 to 2,000 ng/ml. Thus it had to be assumed that the pancuronium level was too low (72 ng/ml) so that symptoms of dystonia recurred. Based on extensive literature research, the described case can be qualified as unique. The therapy concept had been innovative, sufficient and effective for more than 10 years. It allowed the patient to enjoy a maximum of autonomy. Ultimately, death was due to the blocked pancuronium infusion. The relatively low pancuronium level had provoked the dystonia to return with generalized spasms also involving the respiratory muscles resulting in respiratory arrest. During the police investigations, two previous suicide attempts came to light.

The Federal Institute for Drugs and Medical Devices (BfArM) was notified of an event in which it was not possible to sufficiently ventilate a patient suffering a severe asthma attack. It turned out that the ventilation pressures used by the device for pressure-controlled ventilation were below the values set by the user, which the user was not aware of. The ventilation pressures chosen by the user exceeded the preset alarm limits of the ventilator. This pressure and alarm management significantly differed from that of other ventilators used in the hospital. This and similar incident reports suggest that safely operating medical devices for anesthesia and intensive care may be impaired when different models of a device are used within a hospital. If different models are used, more device information needs to be stored in memory. Existing knowledge on human memory suggests that the more individual memory items (e. g. different operating rules) are stored, the greater the risk of memory interference and hence of impaired retrieval, particularly if the different items are associated with overlapping retrieval cues. This is the case when different devices are used for a single functional purpose under identical or similar circumstances.Based on individual incident reports and theoretical knowledge on an association between device diversity and use problems, this study aimed to determine the organizational conditions regarding device diversity that prevail in German hospitals. Additionally, the anesthetists' perspectives and experiences in defined clinical settings were investigated.For selected groups of medical devices, the biomedical engineers of German hospitals were surveyed about the different makes used in their hospital. Additionally, questionnaires were sent to a department of anesthesiology of a large University Hospital to investigate the personal experiences of working with different makes and models of a device.Using devices by different manufacturers was particularly frequent for ventilators, but there were also a considerable number of hospitals with syringe pumps and patient monitoring systems from different manufacturers. Almost all participants stated that they work or have worked with different models of a device. The majority of respondents had encountered problems or errors, which they ascribed to the requirement to learn a different method of operation for each device; however, they also listed various benefits, for instance the possibility to optimally address the requirements of specific situations or patient groups. Both biomedical engineers and anesthetists suggested a homogeneous device pool within the hospital and regular and repeated training sessions for each device model used.Using different device models for anesthesia and intensive care seems to be common in many German hospitals, particularly for ventilators. An association between device diversity and problems operating a device is plausible, given the functioning of human memory. This topic should be investigated by future studies in order to identify factors that may contribute to such problems and possible solutions for clinical settings. Likewise, the potential benefits of having different device models at one's disposal should be evaluated. To pinpoint the measures that will be most effective given the specific settings of the individual hospital, all underlying clinical and economic considerations must be carefully balanced against the associated potential risks.

Besides reliable efficacy and patient satisfaction, economic efficiency is becoming increasingly more important in postoperative pain management.The present study investigated the effectiveness of two pain pump systems and compared the running costs in treatment.In this study 40 patients received an interscalene catheter prior to shoulder surgery. Postoperative pain management was provided via an electronic pump with patient-controlled analgesia (PCA) or a mechanical pump without PCA. Patients kept a pain log. After treatment they were interviewed about their satisfaction with the pump. In addition drug consumption, nursing material, staff time for handling and maintenance of the pumps and preparation of medications pro re nata were assessed.Postoperative pain levels and patient satisfaction were comparable in both groups. Economically, the electronic pump was more cost-effective than the electronic model for a duration of treatment of 1 and 2 days. With treatment duration of 2 days the costs of both pumps were equivalent; however, the PCA feature of the electronic pump allowed a reduced intake of systemic analgesics on demand.Both pain pump systems provide equally effective pain management, while the electronic model caused less costs. Both pumps offer advantages and disadvantages that should be considered based on local circumstantial demands.

The influence of desmopressin on hemostasis is mediated by the release of von Willebrand factor and of coagulation factor VIII from vascular endothelium. The necessity of testing desmopressin effectiveness on hemostasis is a matter of controversy and the performance of the test is not yet standardized. For this reason the desmopressin tests in 114 children with von Willebrand syndrome (type 1, n=98; type 2A, n=12; type 2M, n=2; type 2N, n=2) carried out in 7 paediatric haemostaseologic centers were retrospectively analyzed. The effectiveness of desmopressin was assessed using defined response criteria. As expected, the test performance showed a wide variation among the centers. In 99 children desmopressin was given intravenously as a short infusion at a dosage ranging from 0.25 to 0.41 microg/kg and in 15 intranasally at an absolute dose of 40 to 300 microg. The points of time for blood taking after desmopressin application ranged from 0.5 to 12 h. The absent desmopressin response in 7 patients (6%) and the partial response in 15 indicate the necessity of testing desmopressin effectiveness before the first therapeutic use. The application of desmopressin was well tolerated by the patients.

Epidural analgesia and continuous femoral nerve blocks are often used for pain therapy after total knee arthroplasty. The additional use of a continuous sciatic nerve block is controversially discussed. To avoid the problem of inaccurate placement a stimulating catheter may be useful. The aim of this study was to compare the effectiveness of a continuous femoral nerve block with an additional continuous sciatic nerve block for improved functional recovery and pain relief.An open randomized prospective controlled study was carried out with 54 patients to receive either a stimulating catheter placed in the femoral nerve sheath or two stimulating catheters placed in the femoral and in the sciatic nerve sheath or an epidural analgesia. Pain was recorded with the visual analogue scale at rest and with passive motion of the knee during the first 3 postoperative days. The angle of nearly pain-free bending of the knee, side effects and opioid consumption were recorded.The reported pain scores and opioid consumption did not differ significantly between the groups. However, functional recovery up to the third postoperative day was significantly worse in the femoral catheter group.Using stimulating catheters for pain therapy the three methods are largely comparable and other parameters should be used for individual selection.

A multimodal perioperative therapy strategy (fast-track) decreases the morbidity of general thoracic interventions and increases postoperative reconvalescence after lung resections. Thoracic surgery is associated with relevant pain and sufficient pain relief is essential for postoperative recovery. Epidural analgesia leads to adequate pain control with only minor side effects and complications and can therefore be a reasonable supplementation in a modern fast-track setting. The purpose of this study was to evaluate the benefits and risks of an epidural catheter placed prior to surgery and to analyse the postoperative recovery of patients undergoing thoracic surgery.277 patients undergoing pulmonary resection through an anterolateral thoracotomy were included in our study. Epidural analgesia was carried out through placement of an epidural catheter equipped with Naropine-Sufenta perfusor prior to surgery. Perioperative clinical parameters as well as postoperative management were evaluated. Pain intensity was documented using the visual analogue scale (VAS). Side effects and complications were summarised in five grades of severity (1-5). Insufficient pain relief was recognised when a VAS4 was registered.Median patient age was 59 years, the male / female relation was precisely 2 : 1, on average epidural analgesia was carried out for 4.9 days. Severe complications (grade 4 or 5) were not found. In 37 % of the cases, minor complications and side effects were found, in 1 % clinical relevant complications led to further diagnostic measures. For sufficient pain relief, 10 % of the studied population needed additional treatment with systemic opioids.We have shown that epidural analgesia in patients undergoing thoracotomy leads to sufficient pain control with only minor disadvantages and complications. These are easily mastered without expensive diagnostic or therapeutic interventions. Therefore, epidural analgesia is a safe and helpful tool for increased postoperative recovery within a modern fast-track setting.

This case report of a 54-year-old patient, with a metastasized non-small cell bronchial carcinoma, shows us the different ways in pain therapy alternatives. We report the possibility of using spinal delivery systems (especially epidural/intrathecal) in palliative therapy, if like in this case oral applicated opioids were not very successful. We discuss the advantages and disadvantages of this method and point out the possible side effects. Finally, we conclude that it has to be decided on a case per case basis, if this therapy is applicable or not.

Over the last 10 years the technique of target-controlled infusion (TCI) has substantially influenced the development and practice of intravenous anaesthesia. It opened the possibility of many new and exciting applications of perioperative anaesthetic care. More recent and current developments, such as open TCI (target-controlled infusion) and the availability of generic anaesthetic agents combined with modern infusion pumps, means that TCI can become a standard procedure in anaesthesia and is no longer just a research tool for specialists and enthusiasts. This review explains the fundamentals and applications of intravenous drug delivery by TCI and gives practice guidelines to successfully implement the technique into clinical practice. The aim is to provide a comprehensive reference based on clinically proven evidence.

In anaesthesiological and intensive care practice patients are increasingly being treated with implanted medication pumps. Basic knowledge on the special aspects of this form of therapy is therefore important. During the preanasthesiology visit, information on the pump, the intrathecal catheter, type and dosage of the medication as well as the next scheduled refilling must be collected and documented. Needle punctures near the pump and the catheter must be avoided. During intensive care treatment any possible interaction and overdosing or underdosing of the intrathecally administered medication must be considered. Information on the schedule and punctual organisation of refilling are important to avoid complications.

The local therapy of inner ear diseases provides a means of directly applying pharmacological substances and delivering electrical stimulation to inner ear structures. Problems relating to dosage, systemic effects and the blood-cochlear barrier are thus avoided, which is not the case with systemic therapy. The preferred access point is the membrane of the round window.An appropriately shaped catheter (DURECT Corporation, Cupertino, CA, USA), whose double-lumen passage system permits the variation of concentration and flow, is inserted into the round window niche. In a prospective, placebo-controlled clinical study, this application system was tested in 20 patients with chronic tinnitus. Following implantation the substances lidocaine, glutamate, glutamic acid and caroverine were applied via an attached external micropump.The values for tinnitus loudness, level of irritation caused by the tinnitus and subjective effectiveness of the therapy - measured by means of the visual analog scale (VAS) - showed no significant change, although the most marked improvement was indicated for caroverine.These results indicate that a positive effect was observable only in a proportion of the patients. Continuous therapy of tinnitus and inner ear diseases will only be possible once a totally implantable microdosage system has been developed.

We are reporting on the case of an 11-year old girl with a malignant tumour. The extreme pain throughout the body could not be treated by conventional methods. By intravenous application of a morphine and s-ketamine mixture we were able to achieve a very effective analgesic result. Apart from the opiate effect of the morphine the decisive factor was the NMDA-antagonism of the s-ketamine. The latter suppresses central sensitisation and chronic pain and reduces or even prevents the development of opioid tolerance. It was possible to use smaller opiate doses more effectively, thus reducing the side effects of the pain therapy. Under associated whole-body thermochemotherapy the girl experienced general pain relief and we were able to return to conventional therapy with a fentanyl plaster.

Based on a computer simulation programme, the accuracy of the Graseby 3400 syringe pump was tested for its use in a feedback control system of the neuromuscular block. Firstly, a calculation of errors to determine the difference between the target and actual flow rates was carried out. Next, the characteristic curves of the syringe pump were determined under different flow and sampling rates to correct the application software of the feedback controller with a view to obtaining the correct flow rates online. It was discovered that, particularly with short 12 s sampling rates, dose-dependent errors of almost 100% were provable. Therefore, the application of a robust controller and integration of the characteristic curves at the outlet of the controller software are required. For the adoption of syringe pumps in medical feedback control systems, definite determination of the actual infusion quantity using an exact calculation of errors is required. Especially in cases of short sampling rates in combination with low infusion quantities, the syringe pump comes almost to a standstill, which results in extreme differences between target and actual flow rates.

Application of highly concentrated short-acting vasoactive drugs in the critically ill patient requires precisely working syringe pump systems for continuous intravenous drug delivery. We performed a bench study to investigate the consequences of small amounts of air entrapped within a 50-ml infusion syringe. In particular we studied the effect of entrapped air on drug delivery after moderate vertical displacement of the pump by 50 cm (e.g. in preparation for transport) and the effect on the time required to trigger the pressure alarm after occlusion of the infusion line. At a flow rate of 1 ml/h, lowering the syringe pump prolonged the zero-drug delivery time from (mean +/- SD) 4.1 +/- 0.8 min (without air) to 6.2 +/- 0.9 (with 1 ml air) and to 13.1 +/- 0.9 min (with 2 ml of air, p0.001 for all comparisons). Entrapping of 2 ml of air within the syringe resulted in a 2.6-fold prolongation of the occlusion alarm time after accidental occlusion of the infusion line and a 3-fold increase of the resulting infusion bolus after occlusion. Enclosed air within infusion syringes considerably affects the syringe compliance. It increases the susceptibility of constant drug delivery to vertical displacement of syringe pumps and impairs the occlusion alarm function. Therefore, any air in syringe of infusion pump systems should be carefully removed. To avoid infusion boluses of short-acting vasoactive drugs after accidental occlusions, the occluded infusion line should be released to ambient pressure first.

The purpose of this study was the development of a method for fast and efficient analysis of dynamic MR images of the female breast. The image data sets were acquired with a saturation-recovery turbo-FLASH sequence which enables the detection of the kinetics of the contrast agent concentration in the whole breast with a high temporal and spatial resolution. In addition, a morphologic 3D-FLASH data set was acquired.The dynamic image datasets were analyzed by a pharmacokinetic model which enables the representation of the relevant functional tissue information by two parameters. In order to display simultaneously morphologic and functional tissue information, we developed a multidimensional visualization system, which enables a practical and intuitive human-computer interface in virtual reality.The developed system allows the fast and efficient analysis of dynamic MR data sets. An important clinical application is the localization and definition of multiple lesions of the female breast.

Adequate control of postoperative pain does not only improve patient satisfaction, but is also indicated from a medical point of view. Besides conventional non-opioid analgesics and opioids, more sophisticated analgesia concepts like intravenous patient-controlled analgesia (PCA) and epidural analgesia may be indicated. Modalities and practical aspects of these concepts are discussed and briefly described. It is believed that the effectiveness of improved analgesia will be increased by integrating analgesia concepts into a multimodal approach of intensified mobilisation, early enteral nutrition and frequent respiratory therapy of the postoperative patient. In conclusion, there is good evidence of improved analgesia from PCA and epidural analgesia. Data on outcome improvement by analgesia is still contradictory, but improvement of patient satisfaction is without doubt.

Dermatologic surgery is usually possible under local anesthesia, even when large amounts of highly diluted anesthetic solutions are required (tumescent anesthesia). Although special pumps now render such large injections effortless, it is usually still necessary to hold and guide the injection cannula. We have overcome this handicap by injecting anesthetic solutions slowly with an infusomat, which allows slow painless automatic infusion into the subcutaneous layer.The speed of infusion varied between 40 ml and 1500 ml per hour depending on location, size of the operation, and needle size. Volumes usually ranged from 1 ml to 500 ml but rose as high as 1000 ml if necessary. We found it easier to inject larger amounts than with the conventional method. We used 21-gauge to 30-gauge needles with a length of 1 to 10 cm. The anesthetic solution was prilocaine (Xylonest), and the dilution liquid was original Ringer's solution in 500 ml bottles with no additives. The concentration of the solution varied between 0.4% and 0.1%. After setting up the system, the physician even can leave the room. Especially for children and very anxious patients, this feature is calming.We used this type of subcutaneous infusion anesthesia (SIA) in our department to treat 502 patients ranging in age from 3 to 92 years (mean age: 51 years). We performed all kinds of tumor operations (n = 213), dermabrasions (n = 5), scar revisions (n = 21), stripping of the long and short saphenous veins (n = 82), sentinel node dissection (n = 27), complete lymph node dissection of the axilla (n = 12) and groin (n = 17), and 125 other operations as well.There were no severe complications. Postoperative recovery was fast. 110 (91%) of 121 patients who had previously experienced other forms of anesthesia for the same kind of operation preferred SIA.SIA Ringer's solution diluted prilocaine is an economical, safe and comfortable technique for nearly all skin operations, even for children and very sensitive patients.

In Germany a TCI-system for propofol (Disoprifusor-TCI) has been commercially available since spring 1997. We investigated the prediction error and precision of this TCI system as part of a multicentre study. Bias, precision, blood concentrations and dosage of propofol were compared with patients receiving propofol via a manually controlled infusion device.After approval by the local Ethics Committee and written informed consent, 21 patients of ASA-classification I to III scheduled for major abdominal surgery received either a target controlled infusion (group T, Disoprifusor-TCI) or a manually controlled infusion (group M) of propofol. The propofol plasma concentrations were measured by HPLC. The prediction error for each measurement, the median prediction error (MDPE) or bias, the median absolute prediction error (MDAPE) or precision and the divergence (change of the prediction error over infusion time) were calculated for both groups.For all patients in group T (n = 12) the bias of the TCI system was 6.7% and the precision 27.5%. For 70% of all measured plasma concentrations the absolute prediction error wasor = 37%. The divergence was -5.4% per hour. For all patients in group M (n = 9) the bias was 44.2% and the precision 50%. The mean amount of propofol infused per kilogram body weight and hour was significant higher in T (9.0 +/- 1.2 mg/kg/h) than in M (6.6 +/- 1.2 mg/kg/h, p0.005).With a precision of 27.5% the investigated TCI system (Diprifusor-TCI) showed an acceptable inaccuracy, as for TCI-systems a median prediction error of +/- 30% has to be expected due to the inherent variability of pharmacokinetic parameters. Further studies will be necessary to find out whether the investigated TCI system for propofol may offer substantial advantages.

An infusion system that is insufficiently equipped with an alarm device in case the syringe pumps are obstructed, may gravely endanger patient safety. In a patient with septic shock, an obstruction of the infusion system led to periodic application of norepinephrine boli. Sudden haemodynamic disturbances in critically ill patients should be evaluated for pathological causes as well as for technical failure in the infusion system. A sensitive alarming system of syringe pumps may help to eliminate inappropriate drug delivery. For safe infusion of vasoactive drugs the following conditions are highly recommended: a singular syringe pump, a high volume delivery at a low drug concentration, a pressure-controlled infusion device and a short and pressure-resistant infusion system.

Syringe drivers are used in anaesthetics, intensive care and emergency medicine to deliver small volumes of highly potent drugs with continuous, constant and reproducible flow. For early recognition of interruptions of the drug delivery caused by occlusion of the infusion system, an alarm is triggered as soon as the system pressure exceeds a certain limit. The sensitivity of this alarm depends on the flow rate, type-specific cut-off pressure and the elastic parameters of the infusion system. The sudden release of pressure built up in the system after occlusion occurred can cause delivery of an uncontrolled drug bolus and hence an additional hazard.Six syringe drivers that are widely used in clinical practice were tested for alarm delay and bolus delivery in the event of an occlusion in the system. First, the alarm pressures at flow rates of 10, 50 and 100 ml/h were measured. Then the alarm delay time and bolus volumes post-occlusion were assessed, using a basic infusion system (syringe + single infusion set). Finally, several alterations to the system like extension, tap battery with germ filters or branching were made and their impact on alarm delay and bolus volume measured.Because of the great differences in alarm pressures between the devices tested, there were marked differences in the alarm delay at same flow rates. Predictably, there was an indirect proportional link between alarm delay and flow rate. Using the basic infusion system, alarm delays between 23 s and 143 min were measured. In two of the tested syringe drivers, a pressure-release mechanism is activated with the pressure alarm, which prevented bolus application. In the other devices, release of the pressure in the occluded system caused boli of 0.5-7 ml. Variations in the actual syringe volume and insertion of a second connection tube had no impact on alarm delay and bolus volume. Tap batteries, parallel running syringe drivers or trapped air in the system, however, caused marked increase in both alarm delay (107%) and bolus volume (+147%).Unidentified occlusions of the system cause grave malfunctioning of syringe drivers. While applying highly potent drugs, the discontinuation of drug delivery with subsequent bolus application can cause vital danger to the patient. As a result of the significant time delays in the pressure alarms, the devices tested do not provide sufficient protection against unrecognized system occlusion. Syringe drivers with adjustable alarm pressure can be set close to the actual infusion pressure. A further important point is that one should aim at a reduction in the elastic properties of the infusion set because of the great impact on alarm delay and bolus volume.

In a 32 years old patient with advanced gastric cancer epidural analgesia with local anaesthetic and morphine via a thoracic epidural catheter was required because of intractable pain and intolerable side effects of intravenous morphine. In spite of good efficacy it was decided to remove the catheter because of technical problems and the risk of infection during chemotherapy. Analgesic therapy proceeded to non-invasive transdermal fentanyl, using an intravenous fentanyl pca-pump during transition. The equipotent daily dose ratio of epidural morphine to transdermal fentanyl was calculated as 2.25:1.

If multiple myeloma (MM) progresses in patients after chemotherapy with alkylating agents, the combination of vincristine, adriamycin and dexamethasone (VAD) can achieve a response in 40-70% of cases. Because of its low toxicity for haematopoetic stem-cells this form of chemotherapy is often undertaken before high-dose blood stem-cell transplantation. It was the objective of this study to examine effectiveness and complications of ambulant VAD treatment.Within four years VAD chemotherapy was given to 62 ambulant MM patients, administered by microprocessor-regulated pumps via intravenously polyurethane catheters with a safety valve. Response to treatment, treatment-associated complications and infections were documented prospectively and analysed.VAD treatment achieved tumour reduction of more than 25% in 50 of 62 patients. This treatment had to be discontinued in two of 192 pump-infusions because of irreversible catheter occlusion. Eight patients were hospitalised because of infections and two for noninfectious complications. Severe infectious complications (or = WHO grade III) occurred in 4% of treatment cycles.VAD chemotherapy can be performed with a low rate of infection in ambulant patients despite the need for prolonged intravenously infusion of the drugs. But to avoid complications by intravenously catheters, random prospective tests should first be done with oral alkylating agents.

Blood cells pumped by technical systems are exposed to non-physiological mechanical stress. Haemolysis or subhaemolytic damage may occur. Interaction between cells and the artificial material as well as the shear stress are the main reasons for this traumatisation. Up to now in vitro evaluation is the method of choice as no profound theory of mechanical cell damage has existed yet and, furthermore, haemolytic effects exhibit al large biological variability.This study deals with the mechanically induced haemolysis due to blood pumping by infusion pumps (type INCA; Fresenius AG) in dependence on device related as well as blood preserve related (donor, storage time) factors. RBC count, MCV, MCHC, hematocrit, total and extracellular haemoglobin were obtained before and after pumping the blood sample.At a pump rate of 1000 ml/h, 0.06% of RBC (storage duration of 1-3 days) and 0.3% (storage duration of 34-36 days) were destroyed, respectively. Furthermore, it was shown that only gravity induced perfusion of the Intra-Air-system and the tubing system without any pumping lead to a minor, but significant elevation of extracellular haemoglobin concentration. In contrast, a volume flow rate of 2000 ml/h or the 10 times repeated pump process (1000 ml/h) increases haemolysis by only 27% or 520% respectively.It was concluded that any extrapolation from given experimental conditions to other ones must be performed with great caution due to the complex nature of the haemolysis process. Infusion pumps of the INCA-type stress RBC only slightly and may therefore be used for controlled blood transfusion.

The influence of intracoronary enoximone at a dose of 0.075 mg/ kg/10 min on global and regional wall motion and myocardial perfusion (Group I, n = 10) as well as on diastolic LV function (Group II, n = 8) during pacing-induced ischemia was investigated in 18 patients with significant LAD stenoses. The hemodynamic parameters were determined by left heart catheterization, the systolic and diastolic left ventricular function by echocardiography including Doppler technique, and myocardial perfusion analysis was done after intracoronary application of contrast medium. Enoximone did not change either heart rate (79 +/- 9 vs 80 +/- 9 min-1) or blood pressure (LVSP: 159 +/- 7 vs 162 +/- 5 mm Hg) at rest. In the postpacing ischemic period after enoximone, LVEDP fell from a mean of 28.9 to 18.4 mm Hg (p0.001), dp/dtmax increased from 1050 to 1369 mm Hg/s (p0.001) and regional EF from 47% to 58% (p0.01), while global EF remained unchanged (45% vs 47%). ST-segment depression was reduced significantly from 2.3 to 1.5 mm (p0.01). Enoximone induced an increase in myocardial perfusion by 129% (p0.001) in the stenosis-dependent myocardial areas with shortening of the wash-out half-life time of the echo contrast medium from a mean of 14 s to 5 s (p0.001). The isovolumetric relaxation was shortened by 13% (p0.05), the E wave by 5%, and dp/dtmin increased by 17% (p0.01). In summary, intracoronary application of enoximone led to an improvement in both systolic and diastolic LV function without concomitant peripheral effect due to regression of myocardial ischemia.

Pain therapy is a central medical task and a legal duty. Not the anaesthetist but the pain-causing surgeon is responsible for therapy of pain. Pain as a negative sensation is subjective and individual. Postoperative pain is an essential aspect of the topic "pain in surgery". Therapy starts with the awareness of the problem. Effective pain therapy requires clinical competence and application of available therapeutic options. Initial steps of successful pain treatment include: an informative dialogue with the patient, conveying of confidence, and skillful choice of diagnostic and/or therapeutic options. Application of drugs presupposes detailed knowledge of their specific effects. For convincing therapeutic results, one has to analyse different causes of pain. Acute surgical pain is classified and treated according to a three-step scheme: intense pain with strong opioids, intermediate pain with weaker opioids or non-opioids, and slight pain with non-steroidal anti-inflammatory drugs. Opioids are used with caution in abdominal surgery because of their negative effects (obstipation), the same is the case with Novalgin in trauma patients because of its effect on temperature and leukopenia. Patient-controlled analgesia with appropriate devices means further progress for suitable patients. Effective pain therapy within the framework of successful surgery is feasible and influences patients' comfort and possibly even their morbidity and mortality.

Administration of highly concentrated, highly potent, and therefore highly dangerous drugs with syringe pumps is common in modern anaesthesia as well as in intensive care and emergency medicine. Because of their exact flow rates down to1 ml/h, these pumps are predestined for delivery of drugs with short half-lives, such as catecholamines and vasodilators. But intravenous application of drugs with syringe pumps is not without problems. While it is well known that syringes not fixed correctly into the pump can empty themselves by the influence of gravity, it seems not to be known that hydrostatic pressure can influence the flow rate of a correctly connected system even during continuous infusion. In this situation a change of height of the syringe pump in relation to the patient's position can have tremendous effects on hemodynamics due to unintended acceleration or deceleration of the flow rate. This case report demonstrates that the elevation of a connected epinephrine pump while moving a cardiac surgery patient after ACB operation from the operation table into his bed led to critical increases of heart rate, blood pressure and left atrial pressure. In order to quantify the problem we repeated the situation experimentally. It could be demonstrated that the elevation of the syringe pump by 80-100 cm delivers an additional bolus of 4-5 drops as the central venous catheter outlet. Lowering the pump consecutively leads to the opposite effect. In the case reported, the accidentally administered bolus of epinephrine was 12-15 micrograms (we use a concentration of 60 micrograms/ml epinephrine for continuous infusion with syringe pumps). From this accidental observation the following conclusion can be drawn: The change of height, in relation to the patient's position, of a running syringe pump during continuous infusion of highly concentrated cardiovascular drugs may cause considerable, even life-threatening hemodynamic disorders. Even in a closed infusion system (syringe-extension-central venous catheter), hydrostatic pressure influences infusion rate. Elevation of the pump leads to unintended bolus administration, and lowering of the pump is followed by an interruption of the infusion. In the knowledge of this phenomenon, unexpected hemodynamic reactions during transport of critically ill patients cannot always be interpreted as a result of inadequate anesthesia or volume load, but may be a consequence of incorrect handling of the syringe pumps as described in this report.

The patient-controlled analgesia (PCA) or "ondemand analgesia" is a pain-relieving therapy, which is regulated and monitored by the patient himself. Postoperative pain therapy is the main approach for PCA, which facilitates a long-term, individually controlled pain relief. In certain situations we use mechanical PCA-pumps filled with piritramid (Dipidolor) as an opioid-analgetic for reducing postoperative pain. This kind of therapy needs the acceptance and understanding of the patient as a main condition for the success. Beside an increase of patients' comfort and patients' independence of analgetic demand from the medical staff a reduction in postoperative complications can be expected, the time of hospitalisation might be decreased.

The treatment of intractable pain, especially in cancer patients, often sets problems to patient and therapist. While epidural and intrathecal spinal administration of opiates is a routine treatment in pain with a sub-diaphragmatic topography it is almost ineffective in cervicocephalic or thoracic cancer. An alternative here is the administration of morphine into the lateral or third ventricle by a catheter-reservoir system. We report on our experience in the treatment of twenty patients, mostly suffering from cancer (18 cases), from 1990 to 1993. It is shown to be an effective, non-destructive method with minimal side effects in the treatment of nociceptive pain. Analgesia takes effect within a few minutes and the necessary doses are low. Our results agree with those of other authors describing good to excellent results in 95% of patients with somatogenic pain. However, no or only minimal effect is achieved in the treatment of neurogenic pain by intracerebroventricular morphine therapy.

We report about a time saving method of on-table lavage of the colon. For irrigation a balloon-catheter is inserted into the colon through a small caecotomy. This catheter is connected to an irrigation pump which we usually use for abdominal lavage in peritonitis. After mobilisation the oral end of the later colonic anastomosis is led over the lateral abdominal wall into a plastic tube. Now a continuous irrigation with a controlled flow-rate of 1 l/min is achieved with the aid of the lavage pump. As irrigation liquid we use Ringer's solution. Pressure is limited by an overflow mechanism. In addition after rearrangement the high irrigation flow of the system allows a thorough cleansing of the rectal stump. Between 1992 and 1995 we carried out intra-operative colonic irrigation using the method set out above in 24 patients. The average volume was 8.9 l of Ringer's solution. The irrigation itself lengthened the operation time by an average of 10 min.

Intravenous anaesthesia as a defined technique has become popular in recent years, since new developed drugs and more sophisticated application systems were introduced into clinical practice. However, only a minority of anaesthesiologists really practise this new technique. The scientific basis of continuous intravenous anaesthesia has not been spread widely in the anaesthetic community yet. The following review therefore focusses on recent findings and developments in the field of pharmacology, pharmacokinetics, pharmacodynamics and modern application systems of intravenous anaesthetic drugs. The new opioid remifentanil is described, new aspects in the interpretation of pharmacokinetic data are presented and the concept of context-sensitive halftimes as a parameter to estimate the decrease in clinical effect of intravenous anaesthetics is introduced. Drug effect in clinical anaesthesia is a result of equilibration of the drug with the effect site (Biophase). By means of defining the effect site equilibration time (t1/2ke0 and the drugs concentration at which this effect is achieved (Cp50) the pharmacodynamic properties of each intravenous anaesthetic can be characterised. Computerised pharmacokinetic data can be used to generate stable drug concentrations (target plasma concentration) when connected to an infusion pump. These target controlled systems are able to reach a predefined level rapidly and to maintain it. Thus pharmacodynamic interactions of intravenous drugs can be evaluated. The newly found properties of propofol, such as antiemetic, anticonvulsive and antioxidant, and its present clinical use are described. Finally, modern continuous intravenous anaesthetica techniques have been feasible only by the development of efficient application systems. The text gives an overview of the properties of modern syringe pumps and future developments of "smart" pumps.

We present the case reports of 11 Parkinsonian patients who developed acute psychosis under continuous dopaminergic stimulation. Psychopathologically, two of the patients mainly suffered from organic hallucinosis, while nine patients showed the clinical symptoms of delirium. The clinical course and psychopathological findings in these patients did not differ from other acute organic psychoses. However, the symptoms of these dopaminergically induced psychoses varied significantly from the psychopathological findings of paranoid schizophrenic patients who were regularly treated and evaluated in our clinic. These differences in symptoms and clinical course of dopamine-induced and schizophrenic psychosis do not support the hypothesis that the pathogenesis of schizophrenic symptoms can be explained only by a hyperfunction of dopaminergic transmission. Instead, the involvement of other neurotransmitter system must be considered in order to explain the pathogenesis of schizophrenic symptoms on a neurobiological level.

Implantable port catheter systems are becoming increasingly important, as they often permit out-patient treatment for many indications that would otherwise require hospitalization. Moreover, they also increase the safety/reliability of infusion therapy in critical inpatients. For a variety of reasons, the materials used so far, i.e. steel, titanium and various plastics have not been completely satisfactory. The main disadvantage of metallic systems is the formation of artefacts in tomographic images, while the shortcomings of plastics are mechanical, e.g. chip formation and early membrane failure. Against this background, a port catheter system made of alumina ceramic, which is largely free of the disadvantages of the other materials, was developed. The expected advantages in terms of complication rate and radiological artefacts, were fully confirmed by the evaluation of 160 monitored patients.

Patient-controlled analgesia (PCA) is a newer technique for pain management. Patients are allowed to self-administer small analgesic bolus doses, which have been preprogrammed by the physician, into a running intravenous infusion, intramuscularly, subcutaneously or even into the epidural space. Patients' demands are mostly controlled by computer-driven infusion pumps, but can also be delivered by simple disposable devices. Lockout times, concomitant infusions and hourly maximum doses can be set in most PCA pumps. Clinical experience with PCA demonstrates that individual variability in pain sensitivity and analgesic needs are of utmost importance. In contrast to earlier expectations, PCA opiate consumption is usually higher than with restrictive conventional dosing regimes, but without an increase of serious side effects. Such results let assume that many patients under conventional i.m. techniques must be considered to be underdosed. Patients acceptance is generally enthusiastic for self-control. It is suggested that PCA results should be used for the improvement of conventional techniques. PCA has also been found valuable for scientific pain studies, e.g. to determine predictors of postoperative pain, drug interactions and pharmacokinetic experiments. This review concentrates on intravenous PCA during the early postoperative period.

During the last three years at the ENT Department of the University of Lübeck, patients with Ménière's disease have been fitted with an endaural catheter. A portable infusion pump with a fluid reservoir then supplied the ear being treated with a continuous gentamicin solution. On average, 3 ml of a 0.3% solution was given each day of treatment. In comparison with discontinuous application, this technique proved to be advantageous and therapy was easier to direct. None of the 42 patients undergoing this treatment experienced total hearing loss, as opposed to 3 cases of total deafness under discontinuous treatment. Overall, hearing thresholds remained stable in 23 patients. Thirteen patients suffered hearing losses of up to 20 dB, 4 patients had losses of up to 40 dB, and 2 patients had losses up to 60 dB. In these patients high frequencies were mainly affected. Medical checkups were possible in 24 patients for a period of over 2 years. All of these patients experienced marked decreases in the frequency and intensity of vertigo. Additionally, 14 patients no longer suffered from vertigo, while 8 showed symptoms of incomplete compensation. Two patients still had attacks of vertigo after gentamycin treatment, but these attacks were distinctly less frequent than before. The average dose of gentamicin was 95 mg. In comparison with the control group under discontinuous therapy (325 mg), this dose was clearly smaller.

Eighteen patients with advanced Parkinson's disease (n = 13) or dopamine-sensitive dystonia (n = 5) were treated with the dopaminergic agent, lisuride, applied as a long-term subcutaneous infusion. The results were compared with those obtained in a group of younger, and a group of older, healthy volunteers. The liberation of gamma-interferon (gamma-IFN) following mitogenic stimulation of whole blood with phytohemagglutinin (PHA) was highly significantly elevated in comparison with the group of older healthy volunteers, and clearly, but not significantly, elevated in comparison with the younger group. There was no difference between patients with dystonia and those with Parkinson's disease. The effect observed is thus probably due to lisuride. This effect might explain the longer life expectancy and reduced proclivity for infection shown by patients with Parkinson's disease. It needs to be determined whether, on the basis of these initial data, a therapeutic principle for the treatment of diseases that can be directly influenced by gamma-IFN can be derived.

The influence of the drug Betahistin on the cochlear blood flow (CBF) was checked on 15 guinea pigs (6 controls) (Charles River, BFA 350-450 g) by means of the hydrogen clearance method. The hydrogen clearance measurements were carried out under alpha-chloralose-ethylurethane anaesthesia, artificial respiration with simultaneous control of the electrocardiogram, arterial blood pressure and body temperature. The actual arterial pH-value was checked hourly. Indirect measurement of CBF was carried out in the perilymphatic space (basal turn) before and after intravenous application of Betahistin (vena jugularis externa) (dosage: 0.11 mg/kg/min). The mean arterial blood pressure remained within the 10% range during the experiments. Under Betahistin-treatment the CBF showed an significant increase (p = 0.05). Despite this favourable pharmacological efficiency of Betahistin it must be pointed out that the general application of vasoactive drugs, especially of vasodilative drugs, in the treatment of postulated inner ear blood flow disturbances is presently controversial.