[Intratracheal foreign body caused by a sheared endotracheal intubation stylet]. / Intratrachealer Fremdkörper durch eine abgescherte Einführhilfe.

After orotracheal intubation of a 30-year-old man with a flexible tube, a floating foreign body was noticed inside the tube. The subsequent bronchoscopy revealed a second foreign body near the bifurcation of the trachea. Both foreign bodies were removed successfully and identified as parts of the plastic-sheathed stylet. Fatigue of material is discussed as the reason for the broken reusable stylet during intubation.

Gross-total surgery of supratentorial low-grade gliomas under intraoperative MR guidance.

BACKGROUND AND PURPOSE: Length of survival of patients with low-grade glioma correlates with the extent of tumor resection. These tumors, however, are difficult to distinguish intraoperatively from normal brain tissue, often leading to incomplete resection. Our goal was to evaluate the effectiveness of intraoperative MR guidance in achieving gross-total resection. METHODS: We studied 12 patients with low-grade glioma who underwent surgery within a vertically open 0.5-T MR system. During surgery, localization of residual tumor tissue was guided by interactive, near real-time imaging. The amount of residual tumor tissue on MR images was evaluated at the point of the operation at which the neurosurgeon would have terminated the procedure under conventional conditions (first control) and again before closing the craniotomy. RESULTS: Significant residual tumor (more than 10% of original tumor volume) was shown in eight patients at the first control condition. The percentage of resection varied from 26% to 100% (mean, 68%) at this time. Twelve tissue samples from seven patients were obtained in areas identified as residual tumor on MR images. In 10 cases, the neuropathologic investigation confirmed the presence of residual low-grade glioma; in two cases, the borderzone of tumor was identified. In evaluating the final sets of images, we found total resection in six cases, over 90% resection in five cases, and 85% resection in one case (mean, 96%). CONCLUSION: Surgical treatment of low-grade gliomas under intraoperative MR guidance provides improved resection results with maximal patient safety.

The effect of different ventilation regimes on jugular venous oxygen saturation in elective neurosurgical patients.

Since the concept of hyperventilation on neurosurgical and neurotraumatological patients has been contested, our analysis was aimed at its scrutiny on the basis of easily accessible parameters of perisurgical monitoring. Furthermore, the influence of an improved oxygen supply was tested on hyperventilationally induced cerebral changes and to what extent recommendations could be derived for clinical application. In 50 patients (normoventilation FiO2 = 0.4, 0.6; moderate hyperventilation up to a value of paCO2 = 31 mmHg and FiO2 = 0.4, 0.6 and 0.8), who underwent an elective neurosurgical operation at the central nervous system, a fiberoptical catheter was inserted into the bulb of the jugular vein for the continuous monitoring of the jugular venous oxygen saturation (sjvO2), additionally to the regular measures of perioperative monitoring. Approval for this study was given by the Ethics Committee of the University of Leipzig. At five defined times an analysis of arterial and jugular venous blood gas samples was made and their lactate and glucose concentration determined: 1. Immediately after inducing anesthesia; 2. After dura opening; 3. Sixty minutes after dura opening; 4. At dura closing; 5. Sixty minutes after the end of the operation. The lactate oxygen index (LOI) as well as the cerebral oxygen extraction (CEO2) were calculated from primary data. Hyperventilation with a value of FiO2 = 0.4 leads to a significant decrease of the jugular venous oxygen saturation below 55%. It can be positively influenced by increasing the inspiratory oxygen concentration from 40% to 60%. The CEO2 increases, above values of 42% under a hyperventilation of FiO2 = 0.4. This effect can be reversed by increasing the FiO2 value up to 0.6. Under hyperventilation the LOI reaches 'pre-ischemic' values (LOI > 0.03) prior to dura opening. Further decrease of FiO2 to 0.8 has no positive additional effect. Normoventilation with FiO2 = 0.6 induces a decrease of sjvO2 but also a decrease of LOI. Hyperventilation as a routine procedure during elective neurosurgery shall be applied critically and be combined with an increased inspiratory oxygen concentration if necessary. A longterm normoventilation with increased FiO2 should be avoided.

Changes of enzyme activities in the rat myocardium caused by experimental hypoxia with and without ginkgo biloba extract EGb 761 pretreatment. A cytophotometrical study.

Using cytophotometry activity changes of succinate dehydrogenase, glycerol-3-phosphate dehydrogenase and myofibrillar adenosine triphosphatase, were measured in the rat myocardium under normal and different experimental conditions. After hypoxia all enzyme activities were significantly decreased in comparison to the normal situation, and the alterations differed in both ventricles. Ginkgo biloba extract treatment over three months before exposition to hypoxia resulted in a lower inhibition of succinate dehydrogenase, a higher inhibition of glycerol-3-phosphate dehydrogenase and an unchanged activity of adenosine triphosphatase after hypoxia of 20 min. These results were interpreted as a protective effect of the Ginkgo biloba extract on the hypoxic myocardium.

Hypoxia-dependent changes of enzyme activities in different fibre types of rat soleus and extensor digitorum longus muscles. A cytophotometrical study.

Using cytophotometry activity changes of succinate dehydrogenase, glycerol-3-phosphate dehydrogenase and myofibrillar adenosine triphosphatase were measured in 3 fibre types of soleus and extensor digitorum longus muscles under normal and experimental conditions. Fibres were typed by means of cytophotometrical data into slow-oxidative, fast-oxidative glycolytic and fast-glycolytic ones. After experimental hypoxia of 20 min duration a significant increase of enzyme activities was observed especially in slow-oxidative and fast-oxidative glycolytic fibres of both muscles, e.g. succinate dehydrogenase activity increased by 21% in these fibres of soleus muscle and by 23-26% in these fibres of extensor digitorum longus muscle. Moreover, an increase of glycerol-3-phosphate dehydrogenase activity by 10% in slow-oxidative fibres and by 28% in fast-oxidative glycolytic fibres and a 10-12% increased ATPase activity in all fibres of extensor digitorum longus muscle were measured. Treatment with Ginkgo biloba extract for 3 months before exposure to hypoxia resulted in increased adenosine triphosphatase activity in all fibres of both muscles and in decreased succinate dehydrogenase activity of slow-oxidative and fast-oxidative glycolytic fibres of extensor digitorum longus muscle. These results could be interpreted as a protective effect of Ginkgo biloba extract.

Myocardium-protective effects of Ginkgo biloba extract (EGb 761) in old rats against acute isobaric hypoxia. An electron microscopic morphometric study. I. Protection of cardiomyocytes.

Ginkgo biloba extract EGb 761 was used in hypoxia experiments with old rats to investigate its ultrastructure-preserving effects on the myocardium. Hypoxia was performed by means of a hypoxia chamber combined with a commercial narcosis apparatus. N2O/O2-mixture was applied with O2 at 5 vol.% for 20 minutes under normobaric conditions. Ultrastructural-morphometric analysis revealed that EGb 761-pretreatment was able to diminish hypoxic damage at mitochondrial cristae and matrix and also distension of the sarcoplasmic reticulum during acute hypoxic stress. Whereas formation of vacuoles was depressed below the level of controls, the accumulation of lipid drops was not prevented. The preservation of mitochondrial cristae was confirmed by independent secondary morphometric parameters and by cytophotometrically measured activities of mitochondrial enzymes.

Myocardium-protective effects of Ginkgo biloba extract (EGb 761) in old rats against acute isobaric hypoxia. An electron microscopic morphometric study. II. Protection of microvascular endothelium.

Aim of this electron microscopic morphometric study was to demonstrate ultrastructure protective properties of Ginkgo biloba extract EGb 761 on myocardial microvessels of old rats during acute hypoxic stress. Hypoxia of 20 minutes duration with N2O/O2 mixture (5 vol% O2) was performed using a hypoxia chamber combined with a commercial narcosis apparatus. EGb 761-pretreatment diminished significantly the percentage of endothelial cells exhibiting edema, luminal blebs and of capillaries surrounded by pericapillary debris. Hypoxia-related decrease in plasmalemmal vesicle frequency was prevented by EGb 761, formation of vacuoles non significantly diminished against the hypoxic group. Volume density of mitochondrial cristae was significantly less diminished, the volume fraction of degenerated areas less increased in the EGb 761-protected group. The results give some evidence that EGb 761 protects endothelial cell ultrastructure of myocardial microvasculature against hypoxic alterations, probably by its radical scavenging properties.

N2O-induced hypoxia as a model of hypoxic stress of rat myocardium. An ultrastructural-morphometric study.

A model system consisting of a hypoxia chamber combined with a commercial narcosis apparatus adapted to small animals was used to perform a controlled acute isobaric hypoxia on rats with N2O/O2. Ultrathin sections from the left ventricular wall were analysed qualitatively and quantitatively using a computer-aided morphometric program. Compared with the control the cardiomyocytes exhibited a significant increase of volume densities of cytoplasmic vacuoles, lipid drops, sarcoplasmic reticulum, mitochondria, and degenerated intramitochondrial areas. Hypoxic alterations of microvessels consisted mainly in localized endothelial swelling and perivascular edema, protrusions of the luminal surface and moderate mitochondrial alterations similar to those of cardiomyocytes. Further, the number of plasmalemmal vesicles decreased, and the number of vacuoles increased significantly. The results were confirmed by quantitative histochemistry performed by our group in a parallel study. The model can be recommended for studies concerning protective interventions in hypoxia experiments.

The unanticipated difficult intubation: rigid or flexible endoscope?

BACKGROUND: Unanticipated difficult intubation occurs with a frequency between 1.5% and 8.5%. The aim of this study was to compare the use of flexible versus rigid endoscopy in such a patient population, with respect to the preparation time and feasibility of each device. METHODS: During a four-year observational period, 116 patients with unanticipated difficult intubation were managed either with the flexible fiberscope (FFI group, n= 57) or the rigid Bonfils endoscope (RBI group, n= 59) on a randomized basis. RESULTS: The time required for preparing and performing the intubation was significantly shorter in the RBI group: median (IQR) 160 s (118-209 s) as opposed to 229 s (162-326 s) in the FFI group (P=0.001). There were no significant differences with respect to endoscopic visibility or quality of the intubation manoeuvre (P>0.1 each). Causes of unanticipated difficult intubation were mainly as follows: restricted movement of the head and neck (39.7%), a Mallampati class > 2 (35.3%), a short neck (31%) or a thyromental distance < or = 5 cm (28.4%). Postoperative complications associated with the intubation maneuver included slight bleeding (FFI = 8.8% vs RBI = 8.5%; NS), technical problems (12.3 vs 10.2%, NS), hoarseness (15.8 vs 15.3%, P=0.946) and dysphagia (5.3 vs 16.9%, P=0.070). CONCLUSION: Both endoscopic techniques enable quick and safe intubation. The Bonfils method could be the method of choice in cases of already relaxed patients with unanticipated difficult conventional laryngoscopy, presuming that the anaesthetist is familiar with this technique. Because the clinical re-evaluation for possible predictors of difficult intubation revealed no unknown new factors, the preoperative examination for anatomical peculiarities and being aware are the best protection against unanticipated intubation problems.

[Anaesthesiological management in orthotopic liver transplantation -- results of a survey]. / Anästhesiologisches Vorgehen bei orthotopen Lebertransplantationen (LTX) -- Ergebnisse einer Umfrage.

OBJECTIVE: Since there is no therapeutical standard for the anaesthesiological approach during liver transplantation (LTX) in Germany at the moment, we have evaluated the current anaesthesiological procedures during LTX. METHODS: All departments of anaesthesiology (n = 24) cooperating with transplantation centers in Germany received a questionnaire via mail regarding following complexes: anaesthesiological methods, anaesthetics, blood components therapy, perioperative monitoring, supportive cardiovascular therapy and staff. RESULTS: The answers (n = 16) showed following results: Balanced anaesthesia with continuous application of opioids was the standard method (80 %). Different volatile anaesthetics as well as different opioids were used, isoflurane (66.7 %) and fentanyl (53.3 %) were the most common. Veno-venous bypass was never or occasionally used (86.7 %). The differentiated use of catecholamines, based on discussions in the last years, was also reflected in the results. Dobutamine/noradrenaline as combination seemed to be the first choice (46.7 %). Whereas there was an accordance with the employment of blood components, there was a large variation in the effectively applied blood products. Aprotinin was given in 60 % of all clinics occasionally, in 20 % every time and in 20 % aprotinine was never used. In most departments > or = 2 anaesthesiologists (80 %) and 1 nurse (53.3 %) were needed for intraoperative observation. Postoperative medical attendance was provided on anaesthesiological as well as surgical guided intensive care units (ICU). Generally accepted was an early extubation after arrival at the ICU (86.7 %). CONCLUSION: Even though there was a consensus in the anaesthesiological approach during LTX some departments still use different procedures. This is the first study that will give a basis for discussion of anaesthesiological approaches during LTX.

Movement of the upper cervical spine during laryngoscopy: a comparison of the Bonfils intubation fibrescope and the Macintosh laryngoscope.

The movements of the upper cervical spine were measured by fluoroscopy in 20 patients during laryngoscopy with the Bonfils intubation fibrescope and the Macintosh laryngoscope. Laryngoscopy with both the Bonfils intubation fibrescope and the Macintosh laryngoscope resulted in significant extension of the cervical spine as compared to the neutral position but this extension was significantly less with the Bonfils intubation fibrescope than with the Macintosh (p = 0.001). However, the atlanto-occipital distance was significantly greater during laryngoscopy with the Bonfils intubation fibrescope (p = 0.002), and the angle between the occiput and C1 differed significantly between the two techniques (p = 0.001). With the Bonfils intubation fibrescope, significantly less extension was also found at the C1/C2 and C3/C4 levels (p = 0.001 and p = 0.049, respectively). There is therefore significantly less movement of the upper cervical spine during laryngoscopy with the Bonfils fibrescope compared with the Macintosh laryngoscope.

[Anaesthesia for combined pancreatic and renal transplantation in a patient with mitochondrial encepahalomyopathy--a case report]. / Anästhesieführung zur kombinierten Pankreas- und Nierentransplantation bei einer Patientin mit Mitochondriopathie--Ein Fallbericht.

Mitochondrial disorders encompass a group of syndromes produced by genetic defects that disrupt mitochondrial energy production. The impaired mitochondrial energy supply affects nearly all organs and tissues leading to a variable clinical presentation. The possible multisystem involvement complicates the management of anaesthesia and perioperative care. Exact knowledge of the path physiology of mitochondrial diseases may help to avoid perioperative anaesthesiological complications. This report describes the anaesthetic management of a patient with a mitochondrial disorder during combined pancreatic and renal transplantation, and discusses some of the anaesthetic implications of mitochondrial diseases. Due to the potential susceptibility of patients with mitochondrial diseases to malignant hyperthermia, anaesthesia was induced and maintained as total intravenous anaesthesia using propofol, alfentanil and cis-atracurium. In addition, the patient was treated intraoperatively with hydrocortisone (initial bolus of 50 mg followed by a continuous infusion of 4.8 mg/h) and insulin (continuous infusion of 2 IE/h) in order to manage the adrenocortical insufficiency as well as to treat the diabetes mellitus. Using this anaesthetic technique, satisfactory haemodynamic and metabolic conditions were achieved during surgery. The postoperative period, however, was marked by severe respiratory complications.

[The sitting position in neurosurgical operations. Results of a survey]. / Die sitzende Position bei Operationen in der Neurochirurgie. Ergebnisse einer Umfrage.

METHODS: In February 1995 a questionnaire was sent out on perioperative management during neurosurgical operations performed in the sitting position to 136 centres and hospitals within the Federal Republic of Germany that perform neuroanaesthesia. The response rate was 61.02%. Besides the question of perioperative monitoring during neurosurgical operations in the sitting position, we asked about currently used positions for patients during the following neurosurgical operations:posterior fossa, craniospinal and posterior cervical surgery. RESULTS: Of all centres, 32.9% use the sitting position only for posterior fossa and craniospinal surgery. For posterior cervical surgery the sitting and prone positions are favoured by 25.6% of all clinics. Nonspecific basic monitoring (electrocardiogram, pulse oximetry, central venous pressure, invasive or noninvasive arterial pressure) is an accepted standard in all clinics. Capnometry, as a specific monitor for venous air embolism, is used in all centres (100%). Precordial Doppler ultrasound (US) monitoring is used in 69.2% of all clinics; 3.8% use transoesophageal Doppler US as a diagnostic method for venous air embolism. DISCUSSION: The sitting position is the preferred position for posterior fossa and craniospinal surgery in neurosurgical patients in Germany. For posterior cervical surgery the German centres use both the sitting and prone positions. Alternative positions like the lateral or the "park-bench" positions are hardly ever used. The essential monitoring devices for neurosurgical operations in the sitting position, as recommended after the survey by the German Society for Anaesthesiology and Intensive Care Medicine (DGAI) in 1995, are predominantly used. However, the use of Doppler US (precordial or transoesophageal) for the detection of venous air embolism and the preoperative diagnosis of a persistent foramen ovale is not yet widespread. CONCLUSIONS: To determine the effect of the recommendations by the DGAI on clinical practice, the survey will be repeated in 1997.

[HELLP syndrome--a case report]. / Das HELLP-Syndrom--Eine Kasuistik.

A case of HELLP-Syndrome is reported. The age of the patient was 27 years. Diagnostic features, pattern pathophysiology and therapy are discussed.

[Use of the sitting position in neurosurgery. Results of a 1998 survey in Germany]. / Anwendung der sitzenden Position in der Neurochirurgie. Ergebnisse einer Umfrage aus 1998 in Deutschland.

OBJECTIVES: This 1998 survey was carried out on the use of the sitting position for neurosurgical procedures in the posterior fossa and operations of the craniospinal and cervical spine region by the dorsal approach. In addition, anesthetic management of the sitting position and the compliance with recommendations of the Neuroanesthesia Study Group of the German Society of Anesthesiology and Intensive Care Medicine (DGAI) published in 1995 were investigated and compared to results of a 1995 survey. METHODS: A questionnaire was sent to 152 departments of anesthesiology in Germany providing anesthesia for neurosurgical procedures. 85 institutions (56%) responded to the survey, data from 78 hospitals were enrolled into the study. The sitting position was preferred for posterior fossa surgery by 45% of the neurosurgeons, for craniospinal operations by 35% and for cervical spine surgery by the dorsal approach by 39%. To 97% of the institutions the recommendations of the Neuroanesthesia Study Group of the DGAI were well known, 19% modified their anesthetic approach due to these recommendations. Recommendations of the Study Group on neuro-monitoring, in particular on the use of ultrasound (precordially or transoesophageally) for the detection of venous air embolism were followed by all institutions. 45% of the participants of the study preoperatively undertook diagnostic measures to preclude a probe-patent foramen ovale which predisposes the patient to paradoxical air embolism. CONCLUSIONS: The survey demonstrates that the use of the sitting position in German neurosurgery is still high when compared to other Western countries, but a tendency for decline over last 3 years can be observed from our data. In addition, our data appears to indicate a positive effect of the Study Group's recommendations on anesthetic management of the sitting position in neurosurgery.

[Detection of Chlamydia pneumoniae in intrathoracic abscesses--a case report]. / Nachweis von Chlamydia pneumoniae in intrathorakalen Abszessen--ein Fallbericht.

The case of a 52-year-old patient with intrathoracic abscesses following a traumatic fracture of the 11th thoracic vertebral body is described. The abscesses were resistant to conventional antibiotic therapy and attempts at local drainage under CT scan control remained unsuccessful. Finally, chlamydia pneumoniae was isolated using an immunofluorescence technique. Subsequent therapy with doxycycline caused complete resolution of the abscesses. We suggest that in cases of atypical pneumonias and abscesses, infection with chlamydia pneumoniae should be taken into consideration.

[Is the combination of remifentanil and propopfol suitable for transsphenoid resection of the hypophysis?]. / Eignet sich die Kombination von Remifentanil und Propofol für transsphenoidale Resektionen an der Hypophyse?

In a multi-center trial, the feasibility of combining remifentanil (RF) and target-controlled infusion of propofol (P) for patients undergoing transsphenoidal resection of the pituitary gland was tested. After IRB approval, 74 patients (29 male/45 female) were included in the study. The concentration of RF and the target concentration of P were recorded as were heart rate (HR) and mean arterial blood pressure (MAP). For intubation the RF dosage was 0.26 +/- 0.06 microgram.kg-1.min-1 and the target concentration of P was 3.16 +/- 0.63 micrograms.ml-1. After induction, HR and MAP decreased significantly. The painful events of the operation were preparation of the nasal mucous membrane and penetration of the sella turcica. By adjusting the RF dose to 0.31 +/- 0.09 microgram.kg-1. min-1 and the target concentration of P to 3.48 +/- 1.49 micrograms.ml-1, an increase of HR and MAP above initial values was avoided at this time. Hypotension and bardycardia were treated in eight patients (10.8%) with a vasopressor, in four patients (5.4%) with atropine and in four more patients (5.4%) with a combination of these drugs. Two patients (2.7%) needed antihypertensive therapy. The average time interval between the end of P-TCI and spontaneous breathing was 6 +/- 3 min (median 6 min) and till patients opened their eyes 9 +/- 4 min (median 9 min). After 13 +/- 4 min (median 13 min) the patients became orientated. The average doses of analgetics were 19.5 +/- 19.9 mg piritramide and 1.8 +/- 1.0 g metamizol during the first 12 hours postoperatively. Eight patients (10.8%) did not need any analgetics. We suggest that the combination of RF and P as a "fast track concept" can supplement the repertoire of anaesthetic managements used for transsphenoidal resection of the pituitary gland.

[Is the combination of nitrous oxide and hyperventilation in elective neurosurgical operations useful?]. / Ist die Kombination von Lachgas und Hyperventilation bei elektiven neurochirurgischen Operationen sinnvoll?

The use of nitrous oxide (N2O) and hyperventilation (HV) in elective neurosurgery is controversially discussed. The emphasis of the study was to show the effects of N2O and/or moderate hyperventilation (paCO2 31.0 +/- 1.2 mmHg) on parameters of cerebral metabolism: jugularvenous oxygen saturation (SjVO2), cerebral extraction of oxygen (CEO2), arterial jugularvenous difference of oxygen contents (AJDO2), arterial jugularvenous difference of lactate (AJDL) and glucose (AJDGL) and lactate-oxygen index (LOI). The study was approved by the Ethics Committee of the University of Leipzig. Forty patients undergoing an elective craniotomy for brain tumour resection were divided into four groups: group 1: n = 10, N2O + normoventilation (NV), group 2: n = 10, N2O + hyperventilation (HV), group 3: n = 10, O2/air + NV, group 4: n = 10, O2/air + HV. N2O + HV led to a significant decrease in SjVO2 from 68.1 +/- 10.7% to 49.7 +/- 5.6%. O2/Air + HV produced a drop from 67.1 +/- 11.1% to 49.8 +/- 7.7%. CEO2 increased significantly in the group N2O + HV from 30.6 +/- 10.6% to 49.6 +/- 5.5% and in the group O2/Air + HV from 31.7 +/- 11.1% to 50.0 +/- 7.8%. AJDO2 increased significantly in the group N2O + HV from 5.79 +/- 1.54 ml% to maximal 8.49 +/- 1.10 ml% and in the group O2/Air + HV from 5.29 +/- 1.76 ml% to maximal 8.03 +/- 1.76 ml%. In the normoventilation-groups 1 and 3, no significant changes in SjVO2, CEO2 and AJDO2 were observed between MP2 and 4. The parameters AJDL, AJDGL and LOI did not show any significant changes in any of the four groups. The described data represent a reduction of cerebral oxygenation, but deleterious effects caused by cerebral ischaemia could not be observed. Based on our data, hyperventilation and its combination with N2O should not be used routinely in neuroanaesthesia.

[Effect of local anesthetics on hemodynamic effects during Mayfield skull clamp fixation in neurosurgery using total intravenous anesthesia]. / Der Einfluss von Lokalanästhetika auf hämodynamische Effekte beim Anlegen der Mayfield-Klammer in der Neurochirurgie unter totaler intravenöser Anästhesie.

For neurosurgical procedures, the association between insertion of the Mayfield skull clamp and haemodynamic changes is generally recognized. We investigated the protective effect of two local anaesthetic substances (lidocaine and bupivacaine) under the conditions of total intravenous anaesthesia (TIVA) with propofol and alfentanil. Forty-two patients undergoing an elective craniotomy (tumor resection) were included in the study and randomly divided into three groups. All patients were given a total intravenous anaesthesia with propofol and aflfentanil. After induction, the skin areas for the pin were infiltrated with 0.9% sodium chloride (n = 14, control group 1), 1% lidocain (n = 14, group 2) or 0.5% bupivacaine (n = 14, group 3). After an interval of 1 to 2 minutes the pins were inserted. The intra-arterial line was inserted before induction. The haemodynamic parameters heart rate (HR), systolic arterial pressure (SAP), diastolic arterial pressure (DAP) and mean arterial pressure (MAP) were monitored continuously. The haemodynamic parameters were recorded at four set times: (1) after induction of anaesthesia, (2) at the onset of the local anaesthesia, (3) at the insertion of the pin-holder, (4) five minutes after insertion. Insertion of the pins led to a significant increase in HR, SAP, MAP and DAP in the control group. These haemodynamic changes can be reduced by local infiltration with lidocaine or bupivacaine. The effect of both substances was the same in our study. Our results suggest that a significant reduction of the haemodynamic effects caused by insertion of the Mayfield skull clamp can be achieved by the use of local anaesthesia. Total intravenous anaesthesia alone with propofol and alfentanil cannot protect against these haemodynamic stimuli.

[Hyperoxia-induced liberation of big-endothelin into jugular venous blood of electric neurosurgical patients]. / Hyperoxie-induzierte Freisetzung von BIG-Endothelin in das jugularvenöse Blut elektiver neurochirurgischer Patienten.

The use of hyperoxia in emergency situations is generally accepted, but the routine and uncritical application of higher oxygen concentrations is criticized. The influence of short-term application of hyperoxia on cerebral oxygenation, cerebral lactate and BIG-endothelin (BIG-ET) was studied. After approval by the Ethics Committee of the University of Leipzig, 22 patients (hyperoxia group n = 16, normoxia, control group n = 6) undergoing an elective craniotomy were included in the study. After induction of a total intravenous anaesthesia (sufentanil and propofol), a fibre-optic catheter was inserted into the bulb of the jugular vein. The inspiratory concentration of oxygen was raised from 0.4 to 1.0 for 15 minutes. Before, during and after hyperoxia, a blood gas analysis and analysis of lactate and BIG-ET were performed from arterial and jugularvenous blood. Hyperoxia caused a significant increase in jugularvenous oxygen saturation (sjO2) from 60.4 +/- 8.8% to 68.6 +/- 10.4% and jugularvenous oxygen content (cjvO2) from 10.27 +/- 2.06 vol% to 11.76 +/- 2.16 vol%. These changes were reversible after the end of hyperoxia. The jugularvenous lactate decreased significantly (9%) from 1.20 +/- 0.48 mmol/l to 1.10 +/- 0.45 mmol/l after the end of hyperoxia. Hyperoxia led to a significant increase in jugularvenous BIG-ET from 3.35 +/- 0.61 pg/ml to a maximum of 3.82 +/- 0.95 pg/ml and a decrease in the arterio-jugularvenous difference of BIG-ET from 0.19 +/- 0.53 pg/ml to a minimum -0.11 +/- 0.32 pg/ml. The changes in lactate and BIG-ET were also seen after the end of the hyperoxia. In the control group (normoxia, FiO2 0.4), no significant changes in sjO2, oxygen content, lactate and BIG-ET were observed. The increase in jugularvenous BIG-ET and the decrease in the arterio-jugularvenous difference of BIG-ET following hyperoxia indicate a higher cerebral release of BIG-ET.