Anaesthesiologie und Reanimation最新文献

In a prospective clinical study neuromuscular block at the orbicular ocular muscle was examined qualitatively and quantitatively by an AMG approach. The signals were recorded, visualized and evaluated simultaneously under PC-support after TOF-stimulation in 20 s intervals. Fifty ASA I and II patients were included into the study. After oral premedication with midazolam 10-15 mg, anaesthesia was induced with propofol 2 mg/kg and alfentanil 0.02 mg/kg and maintained by means of propofol 6-8 mg/kg/h and alfentanil 0.02 mg/kg/h. After intubation and signal stabilization, mivacurium 0.75 mg/kg was administered and neuromuscular blockade was recorded online. The measured acceleration at the orbicular ocular muscle amounted 0.9 g on average. Maximal neuromuscular block was registered at 78.5% and the TOF-ratio of 0.8 was achieved after 14.1 min. The low values of the AMG-signals of the orbicular ocular muscle requiring very high technical demands on the measuring instrument. Additional problems arise through the considerable temporal expenditure for discovering the optimal location of stimulation. During the AMG monitoring the position dependence of the measured values of the sensors must be taken into consideration. These technical problems restrict the suitability of the AMG at the orbicular ocular muscle as a quantitative neuromuscular monitoring tool.

Central venous catheters (CVCs) can be associated with various complications which arise during insertion, with the catheter in situ or upon its removal. Here we report a case of secondary CVC malposition that occurred despite checks of CVC position by different methods. A subclavian triple-lumen catheter was retracted until intra-atrial ECG indicated reversal to a normal P-wave. Blood was successfully aspirated through all three lumens, and the catheter was fixed at 11 centimeters intracorporal length and used intraoperatively. A postoperative chest X-ray demonstrated an intravenous CVC length of only a few centimeters, which was accepted because of the inconspicuous results of previous monitoring. Fifteen hours after CVC insertion, the patient developed a swelling in the subclavian and right neck region, a pronounced hydromediastinum and small bilateral pleural effusions caused by paravenous infusion through the most proximal CVC lumen. After instantaneous removal of the catheter, the patient recovered without further complications. This case demonstrates that even carefully-fixed multi-lumen catheters can partially dislocate due to a patient's movements or changes of position. Therefore, repeated aspiration of blood from the most proximal lumen should be performed to detect secondary CVC malposition. Moreover, repeated chest radiographs are useful in verifying a correct CVC position and detecting late complications. In summary, CVC complications can occur with delay, are potentially life-threatening and may necessitate repeated checks of catheter position. This case report discusses different approaches to detecting malposition and reviews rare CVC complications.

We report on the case of a 17-year-old male patient who received a PCA pump after nephrectomy for postoperative analgesia. The syringe of the PCA pump was filled with 50 mg morphine and positioned about 25 cm above the heart. Since the piston of the syringe was not bolted while the pump was switched off, an unnoticed accidental evacuation of the whole content of the syringe into the intravenous line of the patient occurred because of gravity. This problem exists not only with PCA pumps, but can happen with syringe pumps in general. The incident, which can only be explained by strongly reduced venous pressure, was detected by chance. No harm resulted for the patient, but under different conditions it could have been lethal. This critical incident was caused by various factors: incorrect application in combination with insufficient experience or training, stress, inadequate handing-over of the patient and a lack of arrangements and instructions for procedures in routine situations. Suggestions for preventing such dangerous critical incidents are made and discussed. In particular, an algorithm for the correct procedure when inserting or changing the syringe of a syringe pump is presented.

We are reporting on postoperative pain treatment using epidural analgesia in 1,822 patients, performed between 1995 to 2000, following continuous epidural anaesthesia combined with general anaesthesia for operations in various specialized areas (general or visceral surgery, vascular and thoraxic surgery, gynaecology, urology and orthopaedics). A total of 1,727 of these postoperative epidurals were included in a detailed evaluation. The postoperative epidural analgesia consisted of a continuous application of 0.25% bupivacain or 0.2% ropivacain. These local anaesthetics were administered epidurally in an hourly perfusion rate of 7.5 ml. We found "good" pain relief through continuous epidural administering of the local anaesthetics in 1,292 patients (74.8%). "Moderate" pain relief was achieved in 392 patients (22.7%). Sufentanil had to be epidurally administered in addition to local anaesthetics in 262 patients (15.2%) in the wake-up room. The sufentanil doses lay between 5 and a maximum 10 micrograms per hour. An additional epidural application of morphine-boli in a dose of 3 mg every 8-12 hours was necessary in 384 patients (22.2%) in the surgical wake-up stations. In 392 patients (22.7%), the additional systemic administering of antipyretic analgesics such as metamizol or paracetamol or spasmolytica was sufficient. In 43 cases (2.5%), sufficient pain relief could not be achieved with epidural analgesia even with additive applications of systemic functioning pharmaceuticals, so that the postoperative pain therapy had to be completely switched to a PCA. The lying time of the epidural catheter was 2-5 days. It was shortest with the gynaecological patients and longest with patients from general, visceral, thoraxic and vascular surgery areas. An important factor for a sufficient epidural analgesia is the exact epidural positioning of the catheter tip in the area of the spinal cord segments, which are affected by the operation. This reveals the required puncture height. The following side-effects resulting from the epidural analgesia were found: blood pressure loss of more than 20% of the starting value (21%), temporary bladder voiding disorders (8%), temporary sensory disorders of the lower extremities (6.5%), seldom nausea (2.4%) and post-puncture headaches (1.2%). The most important prerequisites for successful postoperative epidural analgesia and thus for increased patient satisfaction are correct selection of the insertion height in relation to the planned operation, constantly available medical pain service, the inclusion of trained care personnel and unequivocal written instructions.

In most developed countries, alcohol is a socially tolerated drug. Nevertheless, its consumption is associated with several negative side-effects during anaesthesia. In surgical patients the prevalence of alcoholism exceeds 20%. Chronic alcoholism and acute alcoholism have an important impact on perioperative morbidity and mortality and especially on anaesthetic risk, due to pharmacological interactions, pathophysiological changes and direct pharmacological interactivities between alcohol and narcotics. Symptoms of alcohol withdrawal are a serious and potentially life-threatening complication and should be avoided or the risk for occurrence should at least be reduced. Patients with a high risk of developing perioperative symptoms of alcohol withdrawal can be detected by laboratory tests and questionnaires. The most important implication for anaesthesia is the choice of a rapid sequence induction to reduce the risk of aspiration and the maintenance of haemodynamic stability and liver perfusion. Maintaining body temperature and providing intensive postoperative surveillance and care are necessary. The indications for regional anaesthesia are the same as for other patients (cooperativeness, coagulation, consent, etc.). In general, awareness of possible interactions can reduce perioperative complications and improve postoperative outcome.

A large body of experimental and clinical work leaves no room for doubt that mechanical ventilation can contribute to the progression of a lung disease or, in the worst case, produce acute pulmonary damage. The pathophysiological processes involved have been described as barotrauma, volutrauma, atelectrauma and biotrauma. In response, a socalled lung-protective ventilation strategy has been proposed, especially for patients with acute respiratory distress syndrome (ARDS). Such an approach seeks to apply limited airway pressures, small tidal volumes and appropriate levels of positive end-expiratory pressures even if, as a consequence, non-physiological gas exchange values (i.e. elevated PaCO2-levels) need to be tolerated. A recent large prospective randomized trial demonstrated reduced mortality rates using such a strategy. To support lung-protective ventilation in ARDS patients, an array of therapeutic measures has been proposed, including meticulous attention to fluid and transfusion management, prone position, extracorporeal membrane oxygenation (ECMO), inhalation of nitric oxide, implementation of spontaneous breathing, partial liquid ventilation and tracheal gas insufflation. Of these, only prone positioning has become part of routine clinical management, while ECMO is applied in selected cases only. Unfortunately, thus far, none of these measures has passed the litmus test of a randomized controlled trial. Recent large prospective observational studies, however, suggest that only an optimized concert of therapeutic interventions, but not a single measure alone, may improve the outcome of ARDS patients.

Cis-atracurium is a stereoisomer of atracurium, about five times more potent than the racemate. Whereas cis-atracurium is routinely used in adults, its effects on children are still poorly defined. We compared equipotent doses of atracurium and cis-atracurium in children aged between 2 and 12 years regarding the quality of neuromuscular blockade, the intubation conditions and the occurrence of side-effects. After approval by the ethics committee and with informed parental consent, 84 children (ASA I or ASA II) were randomly allocated to receive either 0.5 mg/kg atracurium (group A, n = 42) or 0.1 mg/kg cis-atracurium (group C, n = 42). In both groups anaesthesia was induced with 15 micrograms/kg alfentanil and 5-7 mg/kg thiopentone. We assessed the intubation conditions according to the Krieg Scale. Anaesthesia was maintained with a nitrous oxide/oxygen mixture of 2:1 and isoflurane in an endexpiratory concentration of approximately 0.6 Vol.%. Neuromuscular blockade was controlled acceleromyographically in response to supramaximal stimulation of the ulnar nerve. We measured the onset time (T1 = 5%), duration of effect (T1 = 25%), recovery index (T1 = 25%-75%) and the recovery time at a train-of-four-ratio (T4/T1) of 0.7. These parameters did not show any significant differences between group A and group C: onset time: 3.1 +/- 1.5 min (group A) versus 3.4 +/- 1.1 min (group C), duration of effect: 34.1 +/- 5.5 min (group A) versus 34.1 +/- 6.5 min (group C), recovery index: 9.3 +/- 3.3 min (group A) versus 9.6 +/- 2.5 min (group C), recovery time at a TOF-ratio of 0.7:49.3 +/- 8.4 min (group A) versus 52.3 +/- 6.6 min (group C). In group A, the intubation conditions were "excellent" or "good" in 98% of the patients, whereas in group C the figure was only 69%. Regarding side-effects, we found significantly more frequent urticaria in group A (6 of the 42 patients) (p < or = 0.05) than in group C, in which no patient showed urticaria. Flush and tachycardia occurred much less frequently and there were no significant differences in the two groups: two patients in group A and only one in group C. The authors conclude that atracurium and cis-atracurium lead to comparable neuromuscular effects in children aged between 2 and 12 years. Only the intubation conditions were better after atracurium, but atracurium was followed by urticaria more often than cis-atracurium.

Oculocardial reflex (OCR) occurs particularly through manipulation of the medial rectus muscle and results in a bradycardic arrhythmia. In children the incidence is between 60 and 80%. After using sevoflurane in clinical practice, the absence or non-occurrence of this reflex was observed. The data of 180 healthy children aged between four and 14 years who had to undergo strabismus surgery under general anaesthesia were analysed: group I (n = 92), group II (n = 88). All children received standard premedication with midazolam, no anticholinergic drugs were administered. During narcosis, analgesia was maintained routinely with alfentanil. In group I sevoflurane was inhaled for hypnosis and in group II propofol was injected as intravenous hypnotic drug. The depth of anaesthesia was adjusted according to clinical criteria. To compare both groups, heart rate (HR) was determined before, during and after surgical intervention. OCR was defined as a heart rate declining by more than 20% from the initial HR.OCR is described in all methods of general anaesthesia. Under sevoflurane the occurrence of the reflex was significantly (p < 0.05) reduced to 14% of all patients as compared to 75% in patients who received a propofol infusion. Sufficient reflex reduction according to the depth of narcosis under sevoflurane in combination with the sympathomimetic effects of this drug could therefore be discussed as a reason for its positive effects. In our opinion, the use of sevoflurane should be considered as an option for general anaesthesia in strabismus surgery.

Monocytes play an important role in humoral as well as in cell-mediated immunity. In the present study, the influences of the anti-migraine preparations metoprolol, propranolol, metoclopramide, acetylsalicylic acid, dihydro-ergotamine and sumatriptan on monocyte chemotaxis were examined in vitro. First, mononuclear cells were isolated by centrifugation from venous blood samples obtained from 10 healthy male volunteers. Chemotaxis was determined using a microchemotaxis chamber. While metoprolol, metoclopramide, dihydroergotamine and sumatriptan did not influence monocyte chemotaxis, high doses of propranolol and acetylsalicylic acid caused a significant (p < or = 0.001) inhibition of this important cellular function. Therefore, it is quite possible that both drugs produce adverse immunological effects in vivo in cases of high dosage or obstruction of elimination.

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.