Medical School

Movements of the liver caused by spontaneous breathing (during sedation or local anaesthesia) or by ventilation during anaesthesia are a source of concern in CT-guided procedures because of the limited spatial and contrast resolution of unenhanced imaging, artifacts caused by the probes and the relatively low temporal resolution of the fluoroscopy mode. During CT-guided radiofrequency ablation (RFA), it is essential that the lesion can be visualized optimally and that the ablation probe is positioned accurately to avoid non-target injuries. We therefore used high-frequency jet ventilation and general anaesthesia to minimize ventilation-related liver movement and provide optimal conditions for a patient undergoing RFA of hepatic metastases. The technical and anaesthetic considerations are discussed, and a specific limitation of transcutaneous PCO 2 measurement during activation of the ablation is reported for the first time.

In this study we evaluated on-line continuous blood sampling in a femoral arteriovenous (a-v) shunt for use in quantitative tracer studies using gamma-emitting radionuclides in animals. The shunt consisted of 40 cm polyethylene tubing (PE-50) guided through a coincidence probe. Two three-way valves allowed blood pressure measurements and tracer injection. Blood flow in the shunt and the impulse response function (IRF) were assessed using heparinized human blood mixed with fluorine-18 fluorodeoxyglucose (FDG). In vivo experiments were performed in eight male rats (300-350 g) anaesthetized with halothane. In three rats, manual blood sampling was performed in parallel with on-line sampling. In another five animals, the arterial whole blood activity was recorded on-line for 40 min. For the experiments 150-180 MBq FDG was injected over 35 s. Blood flow in the shunt was 23.6, 29.2 and 42.8 ml/h at 100, 120 and 160 mmHg, respectively. The IRF was characterized by minimal dispersion (1-2 s FWHM). Deconvolution of the measured arterial input curves with the IRF changed the measured curve only minimally. Whole blood radioactivity concentration derived from manual and on-line sampling were in excellent agreement. The curves derived from on-line sampling were of high statistical quality. In conclusion, a femoral a-v shunt allows multiple manipulations such as measurement of the arterial whole blood activity, continuous blood pressure monitoring, injection of the tracer and collection of blood samples if necessary. It is not associated with blood loss if the collection of blood samples is not required. It is more convenient to use than manual sampling, the peak of the input curve is never missed and the input curves are of high statistical quality.

Purpose: Computed tomography (CT)-guided navigation during percutaneous radiofrequency (RF) ablations of liver and kidney lesions is hampered by respiratory motion and time-dependent lesion conspicuity after contrast agent injection. Therefore, target immobilization by general anesthesia with high-frequency jet ventilation (HFJV) instead of conventional ventilation (CV) with repeated breath-holds may facilitate and speed up navigation of RF ablation probes.

Background: Two recently developed video-optical intubation devices, the video-optical intubation stylet (VOIS) and the angled video intubation laryngoscope (AVIL) were compared for intubation times and success rate in a simulated difficult tracheal intubation setting. Methods: Thirty anaesthetists were asked to perform 5 intubation attempts with both techniques. Intubation times were recorded and the subjective degree of difficulty and preference for each technique were requested. Results: Intubation time with the VOIS was shorter (17.4∫6.8 s) than with the AVIL (22.8∫13.4 s; PΩ0.0001). Four of the 150 intubation attempts with the AVIL were scored as unsuccessful, due to prolonged intubation time (Ͼ60 s). The estimated degree of difficulty was not significantly different.

Handling and efficacy of a new video-optical intubation stylet were assessed in a simulated difficult tracheal intubation setting and compared with a conventional malleable stylet. Forty-five anaesthetists performed 10 tracheal intubations using both techniques. Laryngoscopy was performed by the observer, who created a grade 3 view according the classification by Cormack and Lehane. The time taken to place the tracheal tube and the final tracheal tube positions were documented. Mean (SD) intubation time for the video-optical stylet was 20.4 (7.7) s and for the malleable stylet 10.2 (3.3) s (p , 0.01). With the video-optical stylet the trachea was correctly intubated in all 225 attempts; with the malleable stylet 44 (19.6%) oesophageal and 44 (19.6%) endobronchial intubations occurred (p , 0.01). The video-optical intubation stylet enabled us to recognise inappropriate tracheal tube positions and to correct them immediately. This equipment can be considered a reliable and effective tool for management of the difficult airway.

AT a time when the profession is coming under increasing criticism for its failure to influence significantly the ravages of our modern plagues while maintaining and increasing our interest in the newer and more sophisticated medical technologies, which in themselves play a relatively small part in the total promotion of health, this publication provides a most helpful and useful corrective to our thinking. It is the record of a symposium held in the Royal College of Physicians in December 1978 concerned with the prospects and application of methods for prevention of disease. There are twelve chapters by a distinguished group of experts in their special field. The introduction on 'lessons from past achievements' by Sir John Brotherson is of a high standard and sets the tone for the chapters which follow. These concern a variety of topics such as 'problems in prevention of renal disease', 'health education', two chapters on 'ischaemic heart disease-is diet important' to the concluding chapter on the 'prevention of iatrogenic disease' (The Lilly Lecture) by Sir Eric Scowen. There is much to ponder on in this excellent and timely publication and all the contributions are of a commendable standard and interest. It is highly recommended for all interested in the promotion of health in the community. D.A.D.M.

der Inspirationsphase zum Hub des Ventilatorbalgs. Das AMV res wird dementsprechend von FGF und ID (als Fraktion von 1,0) bestimmt: AMV res =AMV stell +(FGF•ID) Das Sulla 808V-Anästhesiegerät (Dräger, Lübeck) mit Respirator vom Typ Ventilog 1 oder 2 ist weit verbreitet und verfügt in seiner Originalversion über keine FGE. Die fehlende Volumenkonstanz bei dieser Gerätekonfiguration ist einer der Gründe, weswegen der Hersteller keine Beatmung mit FGF < 2 l/min empfiehlt. Außerdem ist die Hubvolumen-Skalierung am Ventiloggehäuse für FGF > 2 l/min vorgesehen, wobei bereits werkseitig eine nur annähernde Übereinstimmung der Markierung mit den effektiven Hubvolumina zugesichert wird. Untersucht wurde ein Sulla 808V mit Ventilog 2-Respirator, welches nachträglich mit einer FGE der Firma Carbamed (Bern-Liebenfeld, Schweiz) aufgerüstet wurde. Um die Auswirkung dieser Carbamed-FGE zu demonstrieren, wurden die Abweichungen des AMV res vom AMV stell in Abhängigkeit von FGF und Inspirationsdauer (ID) bestimmt. Die zunehmende Verbreitung der Anästhesiebeatmung mit niedrigem Frischgasfluß (FGF) erfordert sowohl Kenntnisse über bauartbedingte Varianten von Anästhesiegeräten als auch eine größere Aufmerksamkeit für den Beatmungsablauf. Vom technischen Standpunkt betrachtet unterscheiden sich Anästhesiegeräte u.a. auch in bezug auf das Vorhandensein einer Frischgasentkopplung (FGE) sowie eines Reservoirs zur Zwischenspeicherung des Frischgases [11]. Ohne FGE kommt es bei unverändert eingestelltem Atemminutenvolumen (AMV stell) zu gleichsinnigen Schwankungen des resultierenden Atemminutenvolumens (AMV res), wenn Änderungen des FGF vorgenommen werden [1, 3, 4, 8, 10]. Das Frischgas fließt kontinuierlich ins Kreissystem und addiert sich während

I am delighted to know that there is at least another dreamer, who understands and supports the rationale and the necessity for a holistic and independent anaesthesia system. 1 And I am neither surprised nor offended that my fellow dreamer, Skitek, questions my faith in the industry to develop such a system. Furthermore, I have to admit that I have been too optimistic so far, maybe driven by the somewhat naive belief that a superior system or device might become a reality if there was an outlook for economic success with it. 2 Probably in this case, more than just a profitable business case is necessary to trigger the desired progress. My decadelong, unsuccessful search for an industrial partner in this respect gives credence to his argument. However, dreams and hopes have the inbuilt tendency to surprisingly materialise, even against all odds, after some time.

BACKGROUND AND OBJECTIVE: Sore throat and hoarseness rank, besides pain and nausea, among the most frequent subjective complaints after tracheal intubation for general anaesthesia. Our intention was to determine the incidence of postoperative sore throat from a large sample of patients and thus to identify the most important associated factors. METHODS: We prospectively followed up 809 adult patients who underwent elective surgical interventions and examined their history, the applied anaesthetic techniques, perioperative course and the occurrence, intensity and duration of postoperative throat complaints. The assignment and professional experience of the involved intubators were also assessed. The influence of a multitude of variables on postoperative throat complaints was statistically analysed. RESULTS: Postoperative sore throat was present in 40% overall being significantly higher in female than in male (44% vs. 33%; P = 0.001). The mean pain intensity in the affected patients (n = 323) was 28+/-12 mm on a visual analogue scale where 0 = no pain and 100 = extreme pain. The average duration was 16+/-11 h. Main factors associated with throat complaints were female sex; history of smoking or lung disease, duration of anaesthesia, postoperative nausea, bloodstain on the endotracheal tube and natural teeth. We could find no influence on the occurrence or intensity of throat complaints by the professional assignment or the length of professional experience of the personnel involved. CONCLUSIONS: Postoperative throat complaints frequently arise after tracheal intubation for general anaesthesia in the first 2 postoperative days, but they are of limited intensity and duration.