Anaesthesiologie und Reanimation最新文献

The long predominance of the semi-open anaesthetic system in paediatric anaesthesia has been ended by the introduction of circle systems by Altemeyer. Narcoses in newborn infants, however, are usually performed with a circle system and a fresh gas flow (FGF) that greatly exceeds the ventilation volume per minute required. This prevents a desirable degree of gas climatisation. A reduction of fresh gas flow for anaesthesia in neonates makes high demands on the anaesthesia ventilators. The safety and precision of present anaesthesia ventilators with different principles of function and construction were studied by means of a lung model reducing the FGF from 4.0 l/min to 0.5 l/min. In order to clarify the importance of a reduction of the FGF for the climatisation of anaesthetic gases and heat regulation in neonates we measured the temperatures of the respiratory gas at the tip of the tube and the body temperatures with a temperature sound. We compared 42 newborn patients anaesthetized with either high gas flow (3.0 l/min) or minimal gas flow. Our results showed that ventilators suitable for safely reducing FGF in neonates are available. Not every ventilator, however, offers the degree of precision required. Depending on FGF heat regulation in newborn infants differed significantly. Using high flow ventilation respiratory gas and rectal temperatures declined continuously. When FGF was reduced there was a significant increase of temperature parameters after 25 min (gas) and 35 min (body). Body temperature came back to normal values or stayed normal. Artificial ventilation of neonates in anaesthesia lasting more than 50 minutes should routinely be performed with minimal FGF in order to ensure normothermia.

Compared to atracurium, cisatracurium releases less laudanosine and histamine, but it has a longer onset time. The primary objective of this study was a blinded, randomized comparison of intubation scores and onset times of a threefold ED 95 of cisatracurium using the priming technique with two priming substances cisatracurium itself and pancuronium. To test the effect of priming with cisatracurium or pancuronium on the onset of cisatracurium, 45 patients were anaesthetised with 0.15-0.25 mg/kg alfentanil, 0.25-0.3 mg/kg edomidate i.v. and O2/N2O, and were randomisely divided into one of three groups. After induction, 15 patients were primed with sodium chloride and thereafter received 0.15 mg/kg cisatracurium, 15 patients were primed with 0.01 mg/kg cisatracurium, another 15 patients were primed with 0.015 mg/kg pancuronium and the last two groups received 0.14 mg/kg cisatracurium three minutes later. Neuromuscular response was monitored by adductor pollicis electromyogram (EMG) by stimulating in a TOF pattern. Times for T1 reduction to 75%, 50%, 25% and 0% and T1 recovery to 25% were taken. Intubation was performed 120 seconds after the main relaxant dose and scored in four grades. The two priming groups showed a significantly faster onset of neuromuscular blockade than the control group (cisatracurium priming group: T1 = 0: 178.4 +/- 16.3 sec., pancuronium priming group 171.2 +/- 15.3 sec. vs. control group: T1 = 0: 205.5 +/- 18.9 sec.). Both primed groups showed no significantly better intubation scores, compared with the control group. Using the priming principle, cisatracurium will give good intubation scores 120 seconds after injection with a clinical duration profile comparable to an equipotent dose of atracurium.

Continuous spinal anaesthesia (CSA) was carried out via a 28-gauge spinal catheter in 154 surgical patients at the Department of Anaesthesiology and Critical Care at Radeberg Asklepios-ASB Hospital between May 1992 and March 1999. The method was used preferably in patients aged over 70 (mean age 82.3 years) with high general risk during anaesthesia (ASA III-IV) who underwent orthopaedic or general surgery of the lower limb and hypogastrium. Remarkably, an anaesthetic level of between Th 8 and Th 10 was achieved with the low initial dose of 7.5 mg of 0.5% hyperbaric bupivacaine. Only minimal cardiovascular and respiratory side-effects were observed in comparison to single shot spinal and general anaesthesia. In the whole series, no anaesthesia-related complications were seen. Another benefit of CSA is the option of applying a second dose with longer duration of surgery to keep the optimal anaesthetic level. In addition, the method is suitable for postoperative analgesia over a period of 2 to 3 days.

Recently, transportable capnographs fulfilling the practical demands of emergency medicine have become commercially available (NPB-75, sidestream, Nellcor Puritan Bennett; and Tidal Wave, mainstream, Novametrix). A prerequisite for their use is an accuracy as required for clinical purposes (i.e., pCO2 +/- 2 mmHg). Additionally, environmental conditions in emergency medicine (e.g., changes in ambient temperature) should not have a significant impact on accuracy. The objective of this investigation was to analyse the accuracy of the two capnographs. The accuracy of the pCO2 measurement was evaluated under the following conditions: (1) measurement with three gas mixtures of defined concentrations (gas A: 5% CO2, 95% O2; gas B: 5% CO2, 20% O2, 75% N2; gas C: 10% CO2, 90% N2) related to STPD conditions (STPD = Standard Temperature and Pressure, Dry); and (2) exposure to changes in temperature (from +22 degrees C to -20 degrees C, and from -20 degrees C to +22 degrees C) applying the aforementioned 3 gas mixtures (STPD); and (3) in 20 patients manually ventilated with pure oxygen following endotracheal intubation (i.e., BTPS conditions = body temperature and pressure, saturated). Adequacy of the results was compared to the alveolar gas monitor AGM 1304 (Bruel & Kjaer, Copenhagen, Denmark; sidestream) which served as the reference method (providing an accuracy for the alveolar carbon dioxide partial pressure (pACO2) of +/- 1 mmHg). In the 3 dry gas mixtures, mean inaccuracy proved to be +4.5 +/- 4.1, +2.8 +/- 3.7, and +2.2 +/- 7.0 mmHg (gas A, gas B, gas C; STPD) with the Nellcor sidestream device. Using the Novametrix mainstream capnograph the results were found as follows: (1) -1.1 +/- 0.6, +2.9 +/- 0.6, and +5.6 +/- 2.3 mmHg (oxygen compensation enabled); and (2) +0.2 +/- 1.6, +2.2 +/- 0.6, and +3.2 +/- 4.2 mmHg (oxygen compensation disabled). After changing the environmental temperature (-20 degrees C / +22 degrees C), the resulting deviations (gases A-C, STPD) found with the Nellcor device averaged -12 +/- 4% and +15 +/- 3% (Nellcor); with the Novametrix mainstream device the deviations averaged -1 +/- 2% and +1 +/- 1%, and -2 +/- 1% and +1 +/- 1% (oxygen compensation enabled/disabled). Mean inaccuracy of the pCO2 measurement during ventilation of patients with pure oxygen (BTPS) was found to average -0.9 +/- 0.9 (Nellcor), and either +3.9 +/- 0.8 or +2.1 +/- 0.7 mmHg with the Novametrix (oxygen compensation enabled/disabled). Under BTPS conditions, both devices showed an acceptable deviation of the measurement accuracy up to a maximum of +/- 2 mmHg. The higher deviations of the "NPB-75" (Nellcor Puritan Bennett, sidestream) when using dry gas mixtures (STPD) may be explained by the automatic water vapour correction. Under the conditions of low and changing ambient temperature (-20 degrees C, +22 degrees C), only the "Tidal Wave" (Novametrix; mainstream) remained uninfluenced, whereas deviations of -12% and +15% were found with the "NPB-75".<

The preemptive use of analgetics makes it possible to influence sensitization proceedings caused by a trauma. Various mechanisms are effective in central pain treatment. The NMDA receptor plays an important role. The investigation presented was to examine whether an intraoperative combination of analgetics with different points of contact leads to improved postoperative analgesia. Altogether 39 female patients who had to undergo a gynaecological laparotomy were examined. Three groups of 13 patients were randomly formed. In addition to usual general anaesthesia, the patients of group one received 0.5 mg/kg bodyweight ketamine racemate before the skin incision and thereafter 10 micrograms/kg/min ketamine infusion continuously until peritoneum closure and then sodium chloride 0.9% as a placebo after the final skin suture. The patients of group two received placebos before the skin incision and intraoperatively and 0.5 mg/kg bodyweight ketamine after the last skin suture. In group three the patients received placebos at all three points of time. Analgetics consumption, pain intensity, awakening reaction, vital parameters as well as psychomimetic side-effects and nausea/vomiting were listed postoperatively. Between the groups no differences were found regarding postoperative analgetics consumption. In addition, the pain intensity showed no differences regarding an improved postoperative analgesia through the combination of analgetics with different points of contact. The intraoperative combination of ketamine and alfentanil does not lead to a reduction of postoperative pain. No preemptive analgesia is clinically provable.

Stenoses of the larynx and trachea may cause acute life-threatening situations. Surgical procedures in patients presenting this type of problem are a real challenge for the surgeon and the anaesthesiologist. Depending on the extent and the nature of the stenosis, the insertion of a stent may be the best therapeutic option. In this case, the high frequency jet ventilation offers certain advantages for the surgeon. Thanks to modern jet ventilators with automatic pressure monitoring and jet ventilation tubes with a separate lumen for pressure monitoring, the danger of barotrauma is considerably reduced, even in patients with a high-degree stenosis of the larynx and trachea. During insertion of a tracheal stent during jet ventilation, the complete cross-section of the trachea must at least be temporarily available to the surgeon. In addition, at the end of the operation the newly implanted stent should not be altered by manipulations necessary for artificial respiration. We describe a new method which uses tracheal jet ventilation for implanting a stent with only short interruptions of artificial ventilation. During recovery from anaesthesia, there is no risk of dislocating the newly placed stent.

It was the aim of this study to compare total intravenous anaesthesia (TIVA) with balanced anaesthesia using modern short-acting anaesthetics for ENT-surgery in children regarding the influence on haemodynamics, recovery, side-effects and costs. After approval of the Ethics Committee of the Medical Faculty of the University of Rostock, 80 children in the age of 3 to 12 years, rectally premedicated with midazolam (0.3 mg/kg) and atropine (0.01 mg/kg), were randomly assigned to TIVA (group 1, n = 41) and balanced anaesthesia (group 2, n = 39), respectively. TIVA was induced with propofol (2 mg/kg) and remifentanil (1 microgram/kg) and maintained with propofol (6 mg/kg/h) and remifentanil (0.2 microgram/kg/min). Controlled ventilation was performed with an air/oxygen mixture (1:1). Balanced anaesthesia was induced with the method of "single breath induction" using sevoflurane (8 Vol.%) in a mixture of nitrous oxide/oxygen (2:1). For maintaining balanced anaesthesia under low flow conditions, sevoflurane concentration was reduced to 1 Vol.% while the nitrous oxide/oxygen mixture was kept constant. Additionally 0.1 microgram/kg/min of remifentanil was given. For controlled ventilation, the patients of both groups were primarily relaxed for intubation with mivacurium (0.2 mg/kg) under continuous monitoring using TOF-stimulation (TOF-Guard). Further relaxation was performed with doses of 0.05 mg/kg of mivacurium after relaxometric control reached T1-level > 20% and T2-level > 0. Haemodynamic parameters (heart rate, mean arterial blood pressure), awakening time (time until the first spontaneous movements occurred), recovery time (according to Aldrete-Score > 8), side-effects (sevoflurane-induced excitation and propofol-induced pain due to the injection during induction of anaesthesia, postoperative vomiting) and costs for anaesthetic agents and relaxants were registered. The investigation showed significantly higher heart rate (p < 0.05) and significantly lower mean arterial pressure (p < 0.05) during balanced anaesthesia than during TIVA. Between the two groups there were no statistically significant differences regarding awakening time, recovery time and incidence of postoperative vomiting. In the TIVA-group, pain due to injection of propofol occurred in 10 patients (24.4%) and in group 2 sevoflurane-induced excitation during induction was registered in 22 patients (56.4%). Based on our presently existing purchase prices for the drugs used, there were no significant differences between the costs for TIVA and balanced anaesthesia. We conclude that both TIVA and balanced anaesthesia performed with short-acting anaesthetics, are suitable anaesthetic methods for ENT operations in children. Because balanced anaesthesia with sevoflurane led to higher heart rates, this kind of anaesthesia should be used with caution in children with heart diseases. The main advantage of both methods is their short recovery time.

To improve the success of blind intubation through a laryngeal mask, Dr. A.I.J. Brain constructed the intubating laryngeal mask airway (ILMA), marketed under the name Fastrach. The new construction allows blind intubation with highly flexible endotracheal tubes up to 8 mm ID with cuff (straight Woodbridge type), securing the airway around the intubation process and maintaining most of the characteristics of a standard laryngeal mask airway (SLMA), including contraindications. An additional contraindication is the existence of a Zenker diverticle. Up to now, eight working groups reported a success rate of blind intubation through the ILMA of more than 90% in about 1,200 patients, with a success rate of blind intubation of more than 50% for the first intubation attempt. Ten percent of the patients were difficult to intubate with the same success rate for blind intubation as in normal patients. Reduced mouth opening does not seem to hinder the use of the ILMA in spite of its increased outer diameter of 2 cm, as long as it is possible to enlarge the mouth opening to > 2 cm during anaesthesia. The new ILMA more than doubles the success of blind intubation compared to an SLMA, irrespective of a large variety of intubation difficulties. Correct judgement of endotracheal tube position is mandatory. The ILMA has the potential to be used in patients who are difficult to intubate and to substitute the SLMA in "cannot ventilate--cannot intubate" situations. The future will show if the ILMA also will improve emergency airway management by inexperienced personnel, including intubation, as has been shown for the standard laryngeal mask airway in cardiopulmonary resuscitation for ventilation only.

Acute thoracic aortic dissection is a life-threatening illness. It is often difficult to diagnose preclinically due to its many possible symptoms. One out of three patients has neurological deficits. The prognosis depends on rapid diagnosis and immediate adequate therapy. Therefore, every emergency physician should know the signs and risk factors of this disease. The most important goals of prehospital therapy are management of pain and anxiety and pharmacological control of the systolic blood pressure and heart rate. We report on a 46-year-old female patient who developed neurological deficits caused by an acute thoracic aortic dissection.

To evaluate the enhancement of mivacurium-induced neuromuscular block by potent inhalational anaesthetic agents, dose-effect curves for mivacurium were determined in 84 patients scheduled for minor elective surgery during anaesthesia with 1.5 MAC (70% N2O) desflurane, sevoflurane and isoflurane and compared with those under total intravenous anaesthesia (TIVA). Acceleromyography (TOF-Guard) and train of four (TOF) stimulation of the ulnar nerve were used (2 Hz every 12 s). Mivacurium was administered in increments of 25 micrograms kg-1 until a depression of T1 > 95% was reached. ANOVA was used for statistical analysis (alpha = 0.05, beta = 0.2). The depression of T1 during potent inhalational anaesthesia was enhanced compared with TIVA. The ED50 and ED95 of mivacurium were 27 +/- 11 (SD) and 58 +/- 26 micrograms kg-1 for desflurane; 28 +/- 10 and 64 +/- 23 micrograms kg-1 for sevoflurane; and 27 +/- 13 and 55 +/- 27 micrograms kg-1 for isoflurane and were significantly lower than the 35 +/- 7 and 71 +/- 20 micrograms kg-1 for TIVA. The duration 25% revealed a significant difference between the volatile anaesthetic groups (10 +/- 2, 11 +/- 3, 11 +/- 3 min respectively) and the TIVA control group (8 +/- 3 min). The recovery index 25/75 and TOFO.80 were significantly prolonged by desflurane, sevoflurane and isoflurane compared with TIVA (RI25/75 9 +/- 4, 9 +/- 4, 10 +/- 5 respectively vs. 5 +/- 2 min; TOFO.80 27 +/- 10, 28 +/- 9, 29 +/- 9 respectively vs. 18 +/- 4 min). We conclude that the neuromuscular blocking effect of mivacurium is enhanced during anaesthesia with desflurane, isoflurane and sevoflurane compared with TIVA. The duration of action and the recovery time are prolonged. The dose of mivacurium used should be reduced if anaesthesia is maintained with volatile anaesthetics.