[Neuromodulation of spasticity in children by intrathecal baclofen]. / Neuromodulation der Spastik bei Kindern durch intrathekal verabreichtes Baclofen.

INTRODUCTION: Treatment with intrathecal baclofen (ITB) is an important part of the complex therapy of patients with cerebral spasticity aiming to improve the motoric functions and to reduce pain intensity. MATERIAL AND METHODS: ITB was started in the Orthopaedic Hospital in Speising in 1999. From 1999 to 2006 a total of 15 children aged 3 to 16 years old were selected for this special treatment. RESULTS: The average degree of spasticity according to Ashworth (scale 1-5) could be reduced by ITB from 4.38 to 3.0, the time spent sitting could be increased from 3.3 to 5.8h per day and the pain intensity (VAS 1-10) could be reduced from 4.2 to 0.6. The time necessary for nursing treatment was shortened from 7.5 to 3.4 (VAS 1-10). Also improved was the emotional situation, the ability to swallow, the posture of the head and the concentration ability. CONCLUSION: ITB provides neuromodulation even in pediatric patients with complex neuromotoric spasticity.

[Pain therapy using stimulating catheters after total knee arthroplasty]. / Schmerztherapie mit Stimulationskathetern bei Kniegelenkersatz.

BACKGROUND: 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. MATERIAL AND METHODS: 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. RESULTS: 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. CONCLUSION: Using stimulating catheters for pain therapy the three methods are largely comparable and other parameters should be used for individual selection.

[Preoperative psychoeducation for a severely traumatized child]. / Präoperative Psychoedukation bei einem schwer traumatisierten Kind.

N., an 8-year-old girl with a long term history of severe sexual abuse and maltreatment with consecutive mental disorders, was scheduled for surgery of clubfeet. The team consisting of an anesthesiologist, a psychologist and a pediatrician decided to prepare the girl for surgery without time pressure. In a first step we applied psychoeducation to obtain a certain degree of confidence. Psychoeducation is a special form of psychological treatment aiming to define cause and goal of surgery together with the patient and relatives. In a further step the anesthesiologist familiarized her with the surgical procedure and the operating theatre. Finally a careful anesthesia with a pain-free postoperative period was applied. Even extremely traumatized children can be prepared for surgery by the help of psychoeducative methods, without time pressure, a careful and pain-free anesthesia and an experienced team of doctors.

Right ventricular function in early septic shock states.

OBJECTIVES: To define a variable which could reliably predict when fluid resuscitation as monotherapy is not expected to improve organ perfusion pressure, owing to limitations in cardiac output responsiveness in patients with severe sepsis. DESIGN: Prospective controlled trial. SETTING: Anesthesiological ICU in a university hospital. PATIENTS: Twenty seven patients in early septic shock states (MAP < 60 mmHg). INTERVENTIONS: Infusion therapy was titrated until no further increase in cardiac index and mean arterial pressure could be achieved. Fluid resuscitation as monotherapy was deemed unsuccessful at the end of 2 h if inotropic or vasoactive pharmacologic support was required to maintain a mean arterial pressure > 60 mmHg. MEASUREMENTS AND RESULTS: We investigated the hemodynamic course during fluid resuscitation (2850 +/- 210 ml crystalloids) with special emphasis on right heart function using the thermodilution technique. Eleven patients (group A) had a right ventricular (RV) ejection fraction below 45%. In this group positive inotropic and/or vasoactive drugs were obligatory to achieve and maintain a sufficient perfusion pressure (MAP > 60 mmHg) after fluid challenge. CONCLUSIONS: In 27 septic shock patients investigated, we diagnosed right ventricular dysfunction in 41%. In this specific patient population fluid replacement alone did not succeed in stabilizing hemodynamic variables, therefore necessitating catecholamine therapy.

[Analysis of a blood use list for orthopedic operations]. / Analyse einer Blutverbrauchsliste für orthopädische Operationen.

OBJECTIVE: Is the documentation of blood utilisation, as demanded in the guidelines of serology and transfusion medicine, a proper instrument of quality control for the use of homologous blood saving techniques? PATIENTS AND METHODS: We analysed retrospectively a list of blood utilisation based on 12,482 surgical procedures in orthopaedic surgery. This list included the type of operation, the number of transfused packed red cell units and, if applicable, the type of homologous blood saving technique (preoperative blood donation, mechanical autotransfusion and isovolaemic haemodilution). Total hip and knee replacement patients were divided in two groups according to base line haemoglobin (A: Hb > 13 mg%, B: hB < or = 13 mg%). RESULTS: The increase of the percentage of patients not receiving homologous blood achieved by blood saving techniques is more pronounced in group B. Preoperative blood donation seems to be the most effective technique with a percentage of patients not receiving homologous blood of 93% in group A and 80% in group B of total hip replacement. This high percentage cannot be improved when preoperative blood donation is combined with mechanical autotransfusion or isovolaemic haemodilution. The efficiency of mechanical autotransfusion and isovolaemic haemodilution can be improved by combination of the two techniques. CONCLUSIONS: A list of blood utilisation as presented can serve as a basis for guidelines regarding the use of homologous blood saving techniques. Moreover such a simple statistic provides a means of quality control and provides information about the likelihood of transfusion.

[Right heart function and endotoxemia in animals]. / Rechtsherzfunktion und Endotoxinämie im Tierexperiment.

We used a chronic instrumented ovine model to investigate right heart function following an endotoxin bolus. Primary aim of the experiments was to elucidate the influence of the right heart on the cardiopulmonary system. Furthermore, we tried a thromboxane synthetase inhibitor as a therapeutical approach. At least we investigated the IR-ANF release, as the endocrinal function of the right heart, in this model. Following the endotoxin administration we observed a massive increase of the pulmonary arterial pressure. As a result of the increased right ventricular afterload right ventricular ejection fraction decreased and end-systolic volume increased. Impaired right heart function could not be compensated sufficiently using Frank Starling mechanism. Consequently, decreased left ventricular preload, stroke volume and cardiac output followed. Pretreatment with OKY-046, a selective thromboxane synthase inhibitor, attenuated the increase in pulmonary arterial pressure and prevented the early right heart failure including the drop of cardiac output. Furthermore, OKY-046 changed the thromboxane-prostacyclin relationship. Therefore we consider the cardiopulmonary reactions following pretreatment with OKY-046 as a result of the attenuated right ventricular afterload as well as of the increased prostacyclin concentration. Endotoxin induced hypoxaemia could not be prevented by pretreatment with OKY-046 and might be caused by interstitial edema following endothelial leakage. IR-ANF release in our model, accompanied by polyuria and natriuresis, seemed to be independent of right heart dysfunction and increase of right atrial pressure. We suggest endotoxin or a endotoxin induced mediator as a trigger of IR-ANF release.

[Do baseline haemoglobin-rates point to the efficacy of blood saving techniques?]. / Geben Ausgangs-Hämoglobinwerte einen Hinweis auf die Effektivität Fremdblut sparender Verfahren?*

OBJECTIVE: We tested the hypothesis that blood saving techniques are more effective in patients with a low baseline haemoglobin. METHODS: We analysed retrospectively 1665 total hip replacements and 848 total knee replacements. Patients were divided in three groups according to the baseline haemoglobin (Hb): Group A were patients with a Hb of more than 15 g/dl, group B between 15 g/dl and 13 g/dl and group C with a Hb of less than 13 g/dl. The blood saving techniques applied (Preoperative blood donation, isovolemic haemodilution, and mechanical autotransfusion) aimed to a high patient population which underwent surgery without transfusion of homologous blood. RESULTS: The higher the baseline value of haemoglobin the higher was the patient population without homologous blood transfusion. The lower the Hb the higher was the effectiveness of blood saving techniques. In case of total hip replacement preoperative blood donation increased the patient population without homologous blood transfusion in all three groups significantly. However, in case of total knee replacement preoperative blood donation increased the patient population without homologous blood transfusion only in group B and C significantly. In both surgical procedures the combination of preoperative blood donation with other blood saving techniques did not further increase the patient population without homologous blood transfusion. In total hip replacement mechanical autotransfusion as well as isovolemic haemodilution reduced homologous transfusion in patients with low baseline haemoglobin. However, the increase was more pronounced when both techniques were combined. CONCLUSION: From our data is derived that the likelihood of homologous blood transfusion is greater in patients with a low baseline haemoglobin. However, in case of hip arthroplasty patients with a high baseline haemoglobin also profit from blood saving techniques while in case of knee arthroplasty the efficiency of blood saving techniques in a patient population with a high baseline haemoglobin is negligible. It seems to make sense to evaluate for the different kinds of surgery those patients who profit most from the different blood saving techniques.

The threshold for thermoregulatory vasoconstriction during nitrous oxide/isoflurane anesthesia is lower in elderly than in young patients.

BACKGROUND: Thermoregulatory vasoconstriction minimizes further core hypothermia during anesthesia. Elderly patients become more hypothermic during surgery than do younger patients, and take longer to rewarm postoperatively. These data indicate that perianesthetic thermoregulatory responses may be especially impaired in the elderly. Accordingly, the authors tested the hypothesis that the thermoregulatory threshold for vasoconstriction during nitrous oxide/isoflurane anesthesia is reduced more in elderly than in young patients. METHODS: The authors studied 12 young patients aged 30-50 yr and 12 elderly patients aged 60-80 yr. All were undergoing major orthopedic or open abdominal surgery. Anesthesia was induced with thiopental and fentanyl, and maintained only with nitrous oxide (70%) and isoflurane (0.6-0.8%). Core temperature was measured in the distal esophagus. Fingertip vasoconstriction was evaluated using forearm minus fingertip, skin-temperature gradients. A gradient of 4 degrees C identified significant vasoconstriction, and the core temperature triggering vasoconstriction identified the thermoregulatory threshold. RESULTS: The vasoconstriction threshold was significantly less in the elderly patients (33.9 +/- 0.6 degree C) than in the younger ones (35.1 +/- 0.3 degrees C) (P < 0.01). The gender distribution, weight, and height of the elderly and young patients did not differ significantly. The end-tidal isoflurane concentration at the time of vasoconstriction did not differ significantly in the two groups. CONCLUSIONS: These data indicate that thermoregulatory responses in the elderly are initiated at temperatures approximately 1.2 degrees C less than that in younger patients. Thus, it is likely that elderly surgical patients become more hypothermic than do younger patients, at least in part, because they fail to trigger protective thermoregulatory responses.

Forced-air warming maintains intraoperative normothermia better than circulating-water mattresses.

The hypothesis that forced-air warming preserves core temperature better than circulating-water mattresses was tested in: (a) 16 adults undergoing major maxillofacial surgery, including radical node resection and flap reconstruction; (b) 53 adults undergoing hip arthroplasty, having approximately 25% of their body surface area available for warming; (c) 20 infants undergoing minor maxillofacial surgery; and (d) 10 young children undergoing pelvic or femoral osteotomies. Patients having each type of surgery were randomly assigned to forced-air warming (approximately 40 degrees C) or conductive warming using a full-length circulating-water mattress at 40 degrees C. Forced-air warming was applied to the legs of the adults undergoing maxillofacial surgery and to one arm, the shoulders, and the neck in the adults undergoing hip arthroplasty; a U-shaped, tubular forced-air cover was positioned around the pediatric patients. Core temperatures increased in all patients given forced-air warming and decreased or remained constant in those without active warming. Furthermore, we needed to decrease the temperature of the warmer from high to medium (approximately 37 degrees C) in most patients assigned to forced-air warming to prevent hyperthermia. After 15 h of anesthesia, rectal temperatures in the adults undergoing maxillofacial surgery were 3.4 degrees C higher in the forced-air group (P < 0.01). After 4 h of anesthesia, esophageal temperatures had increased 0.8 +/- 0.5 degrees C in the patients warmed with forced-air and decreased 0.8 +/- 0.3 degrees C in those warmed by circulating-water mattresses (P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

[Differences in the neuromuscular blockade of the larynx and thenar muscles following relaxation with vecuronium]. / Unterschiede in der neuromuskulären Blockade der Kehlkopf- und Thenarmuskulatur nach Relaxation mit Vecuronium.

To objectivate the clinical impression of different neuromuscular depression in the larynx- and limb-musculature, an attempt was made in 5 patients to quantify laryngeal muscle relaxation by electromyographic recordings of evoked responses from the vocalis muscle during endolaryngeal microsurgery. Mechanographic and evoked electromyographic recordings of the thenar muscles were obtained simultaneously. Nearly total suppression of evoked responses at the peripheral muscle site was observed after a bolus dose of either 60 micrograms/kg or 100 micrograms/kg of the nondepolarising muscle relaxant Vecuronium. However, the vocalis muscle was not blocked completely. The neuromuscular depression ranged from 61 to 92% depending on the dose. In no case was the recommended intubating dose (ED 95) of 60 micrograms/kg sufficient for complete relaxation of the vocalis muscle. The present results do not support that the extent and/or time course of intrinsic laryngeal muscle relaxation correlates with peripheral neuromuscular depression in a quantitative manner. The different degree of relaxation achieved by Vecuronium in the hand and larynx is probably due to their different content of acetylcholine receptors.

[The pharmacodynamics of vecuronium on the musculature of the vocal cords and the ball of the thumb. Preliminary report]. / Zur Pharmakodynamik von Vecuronium an Stimmband- und Thenarmuskulatur. Vorläufige Mitteilung.

During endolaryngeal microsurgery, an attempt was made to quantify laryngeal muscle relaxation by electromyographic recording of evoked responses from the vocal cord musculature in 5 patients. Both mechanographic and electromyographic recordings from the adductor pollicis were obtained simultaneously. Following a bolus dose of vecuronium (60 micrograms/kg, n = 3, and 100 micrograms/kg, n = 2), nearly total (97%-100%) suppression of evoked responses at the peripheral muscle site was observed; the vocal cords, however, did not show complete neuromuscular (nm) blockade, but rather varying degrees of nm depression ranging from 61%-92%. The present results clearly show that quantitative information as to duration and degree of neuromuscular depression in the vocal musculature may be obtained by electromyographic recordings of evoked potentials in the clinical setting; it is impossible however, to quantitatively estimate the extent of intrinsic laryngeal muscle relaxation from peripheral nm depression. The pharmacodynamic differences observed might be due to the varying acetylcholine receptor density of the muscle groups studied.

Cardiac function in an ovine model of endotoxemia.

Eight awake sheep were monitored with ultrasonic crystals, positioned at the anterior and posterior left ventricular wall. A left-sided intraventricular pressure transducer and a right ventricular ejection fraction catheter were positioned in the right and left hearts, respectively. After administration of endotoxin (Escherichia coli, LPS 1.5 micrograms/kg in 30 min), the hemodynamic variables showed a triphasic course. Phase I, (0-1 hr post LPS) was characterized by an increased pulmonary artery pressure and a decreased right ventricular ejection fraction. The inability of the right ventricle to compensate for the increased preload resulted in a fall of the left ventricular preload, stroke volume, and cardiac output. Three hours after LPS administration a second drop of the cardiac output was noted (phase II). This occurred as a result of a fall in preload. Eight hours post LPS a hyperdynamic phase (phase III) was distinguished, with a high cardiac output and a low systemic vascular resistance. During this time there was evidence of probable reduced myocardial contractility.

[Monitoring kidney function in abdominal infection]. / Uberwachung der Nierenfunktion bei abdomineller Sepsis.

In ICU patients suffering from abdominal sepsis acute renal failure (ARF) is a common (50% incidence) and often lethal (more than 80% mortality) complication. Continuous monitoring of renal function is necessary for both adequate fluid replacement and early detection of ARF. Using a programmable handheld computer the following parameters are calculated at least daily: creatinine, osmolal and free water clearance, fractional excretion of sodium and potassium and non-saline loss. The clearance values are corrected to 1.73 m2 body surface area. Free water clearance proved to be a particularly valuable guide for fluid therapy as well as for early diagnosis of ARF. In all septic patients renal function is impaired to some degree, since despite increased cardiac output creatinine clearance is only normal or even decreased. More than 50% of our patients with abdominal sepsis develop ARF, resulting in a dramatic increase in mortality. Goal of renal monitoring in sepsis is to detect ARF as early as possible and to differentiate between extrarenal and septic origin to enable immediate surgical treatment.

[Continuous hemofiltration in peritonitis]. / Kontinuierliche Hämofiltration bei Peritonitis.

During a period of 3 years 27 patients in acute renal failure (ARF) due to peritonitis underwent pump driven continuous hemofiltration (PDHF). PDHF caused neither hemodynamic nor metabolic disturbances, which in contrary are frequently seen during intermittent hemodialysis treatment in septic patients. BUN and creatinine levels fell significantly (p less than 0.001) and remained at 60 mg% and 2.0 mg%, respectively (mean values). Severe coagulation disorders occurred in 5 patients; in 2 patients PDHF was continued under protamine administration into the venous line, in 3 patients PDHF was stopped for 24 hours and than started again. Bleeding stopped in all cases, therefore surgery was not necessary. Other major complications of PDHF were not observed. Kidney function recovered in 44.4% of patients, and mortality was 70.4%. This is clearly lower than in abdominal septic patients under intermittent hemodialysis. Despite much higher costs (2.5 times the costs of hemodialysis treatment per day) PDHF seems to be a promising alternative in the treatment of ARF complicating septic multiple organ failure.

Serum vasopressin (AVP) levels in polyuric brain-dead organ donors.

Hydromineral metabolism and serum arginine-vasopressin (AVP) levels were investigated in 11 patients who sustained brain death. They showed various degrees of polyuria with low osmolality and low fractional sodium excretion. Urine osmolality was always below that of serum, and AVP levels were between 1.3 and 50.0 pg/ml vs 0.7-8.0 pg/ml in ten normal subjects. Thus central diabetes insipidus was excluded. A renal mechanism inducing water diuresis has to be assumed. The type of renal lesion, however, remains unclear.

[The use of a rapid infusion system in orthopedics]. / Der Einsatz eines Schnellinfusionssystems in der Orthopädie.

Major orthopedic surgery such as partial resection of the pelvis and subsequent implantation of a prosthesis is highly connected with massive bleeding. Therefore we tested the hypothesis that the use of a rapid infusion device, which was originally designed for liver transplantations, can prevent hypovolemic shock. We studied 20 patients: in one group (n = 10) the iv volume was given in a conventional way (37 degrees C) by use of pressure infusion bags. Patients of the second group (n = 10) received the iv volume via the Rapid Infusion system (Haemonetics Corp., Braintree, MA). We can conclude that with this new device for rapid volume replacement it is possible to keep the patient's vital functions stable even during times of excessive bleeding and to prevent from metabolic consequences following hypovolemic shock.

Bronchial blood flow reduction with positive end-expiratory pressure after acute lung injury in sheep.

Smoke inhalation increases bronchial blood flow (Qbr) and produces edema of the airway system. This study investigates whether the increased Qbr seen 24 h after inhalation injury can be affected by mechanical ventilation with PEEP (5, 10, 15 cm H2O). Sheep (n = 8) previously prepared with cardiopulmonary catheters and ultrasonic transit time flow probes mounted around their bronchial arteries were insufflated with four sets of 12 breaths each of cotton smoke. Different levels of PEEP were added to the mechanical ventilation 24 h after injury; each PEEP level was applied for 45 min. There were significant increases in Qbr and lung lymph flow (QL) associated with a marked decrease in bronchial vascular resistance (BVR) 24 h after injury. However, no change was observed in mean arterial pressure (MAP) or cardiac index (CI). There was a substantial reduction in PaO2/FIO2 (P/F), which indicated a deterioration in arterial oxygenation. The application of varying levels of PEEP decreased Qbr (p less than .05) while BVR increased (p less than .05), but QL and P/F did not. CI and MAP were recorded. After removal of PEEP, none of the cardiopulmonary variables were significantly different from their postsmoke control values. These findings suggest that mechanical ventilation with PEEP markedly decreases the smoke-induced hyperemia edema frequently seen after inhalation injury without any significant alterations in MAP or CI.

Inhibition of thromboxane synthesis reduces endotoxin-induced right ventricular failure in sheep.

BACKGROUND AND METHODS: There is a marked decrease of the right ventricular ejection fraction after the administration of a bolus of endotoxin to sheep. This hemodynamic response may be the result of thromboxane-mediated pulmonary hypertension. Right ventricular function was studied in an ovine model after the administration of endotoxin (1 microgram/kg Escherichia coli) with and without pretreatment with OKY-046, a selective thromboxane synthetase inhibitor. RESULTS: OKY-046 attenuated the endotoxin-induced increase in pulmonary arterial pressure and prevented the early decreases in right ventricular ejection fraction and cardiac output. However, thromboxane synthetase inhibition failed to prevent endotoxin-induced hypoxemia. The marked increase in plasma thromboxane concentrations, which is usually seen after the administration of endotoxin, was prevented by pretreating the animals with OKY-046. On the other hand, increased plasma prostacyclin concentrations were observed in sheep treated with the thromboxane synthetase inhibitor. CONCLUSION: This series of experiments shows that the early endotoxin-induced decrease in right ventricular ejection fraction can be alleviated by the application of OKY-046.

Control of the total artificial heart: new aspects in human versus animal experience.

Control strategies for total artificial heart application have generally been based on experience with healthy animals. Human patients in a bad state of health who have impaired organ functions and who are subjected to intensive care procedures can develop atypical hemodynamic behavior. In these patients, both unstable and hyperstable behavior of the vascular resistance were observed. Therefore, regulation of cardiac output (CO) by pressure parameters only was avoided and CO was adjusted to obtain an appropriate O2-utilization (O2U). Intending to keep the O2U within ranges of 20-25%, we obtained cardiac indexes between 3.3 and 4.4 L/m2/min (CO 6-8 L/min), which is higher than other cardiac indexes reported. A CO of 10.5 L/min was even necessary to obtain an O2U of 30% in a septic patient. This strategy caused a stable driving management and led to a rapid hemodynamic stabilization and general improvement of the patients' condition. Results indicate that it is also very important to monitor metabolic parameters for appropriate driver adjustment as well, especially in the early postoperative phase, and that O2-U is a sensitive and useful parameter for this purpose.