Der Anaesthesist
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Extracorporeal CO2 elimination (ECCO2-R) is a new approach to the treatment of severe respiratory failure. Gas exchange is separated into oxygen uptake by apneic oxygenation through the natural lungs while CO2 is removed extracorporeally with an artificial organ. The physiological conditions of both processes can thus be optimized. ⋯ This is dependent upon gill reduction and skin armor to prevent evaporation leading to a rise in pCO2 from 3-4 to 40 mmHg and a tenfold increase of serum bicarbonate levels. We believe that the developmental history of respiration justifies the use of a bimodal gas exchange system. It is clinically applied as extracorporeal CO2 removal with membrane lungs (ECCO2-R) or, still under investigation, in a hemodialysis-related procedure (extracorporeal bicarbonate/CO2 removal: ECBicCO2).
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Anesthesia machines may not be contaminated with anesthetic vapors when a patient susceptible to malignant hyperthermia (MHS) is to be anesthetized. A clean machine may not always be available, and recommended protocols for preparing a contaminated machine are cumbersome and time-consuming. We suggest the use of an activated charcoal filter that is easily assembled from spare parts available in many anesthesiology departments (Fig. 2). ⋯ All parts are autoclavable. The filter adsorbs anesthetic vapors quantitatively (Fig. 3) without affecting humidity, nitrous oxide concentration, or circuit resistance. Storage of such a filter may obviate the need to keep a clean anesthesia machine available for MHS patients.
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Randomized Controlled Trial Comparative Study Clinical Trial
[The effect of sufentanil in high doses on hemodynamics and electroencephalography activity in coronary patients].
Sufentanil, a synthetic opioid that is 5-10 times as potent as fentanyl, has been suggested by some authors to prevent hypertensive responses to noxious stimuli in patients undergoing coronary artery bypass surgery much better than fentanyl, while in other studies it has failed to maintain cardiovascular stability during surgical stimulation. This study was designed to investigate the cardiovascular and electroencephalographic effects of high-dose sufentanil/O2/pancuronium anesthesia in patients undergoing coronary artery bypass surgery. METHODS. ⋯ Cardiac and stroke volume indexes stayed significantly lower than the awake values, whereas heart rate remained essentially unchanged during the course of the study. There were no statistically significant differences between the groups during all measurements. In the EEG, sufentanil anesthesia was characterized by a decrease in the number of higher frequency waves and an increase in lower frequency (delta) waves, which did not change during sternotomy in 17 of the 20 patients.
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Randomized Controlled Trial Comparative Study Clinical Trial
[Lung inflation or mechanical ventilation in extracorporeal circulation?].
Extracorporeal circulation (ECC), with its shock-like pulmonary perfusion, leads to pathomorphologic and functional pulmonary changes, the postperfusion syndrome. This study investigated the effects of different types of ventilation during ECC on postoperative pulmonary function and the resulting pulmonary blood gas changes. METHOD. ⋯ Pulmonary ventilation during ECC can prevent a post-operative increase in venous admixture. ECC-related pulmonary vascular changes were not affected by ventilation. Middle-frequency ventilation offers no advantage over low-frequency ventilation during ECC, except that the operating field is more quiet.
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Randomized Controlled Trial Comparative Study Clinical Trial
[Air embolism in the sitting position. Oxygen/nitrogen versus oxygen/laughing gas].
Venous air embolism (VAE) is a well-known complication of neurosurgical procedures performed in the sitting position. Nitrous oxide (N2O) intensifies the hemodynamic alterations conditioned by VAE. Therefore the administration of N2O must be discontinued immediately if VAE occurs. Nevertheless, it is still not clear whether N2O should be avoided in such operations as a general policy. The aim of the present study was to investigate the incidence and severity of VAE with O2/N2 as opposed to O2/N2O anesthesia. METHODS. In all, 42 patients (19 men, 23 women) aged 23-80 years were investigated in a randomized order. In all cases an intracranial operation was carried out with the patient in the sitting position. The anesthesiologic management was uniform: modified neuroleptanalgesia (fentanyl, flunitrazepam, droperidol), relaxation with pancuronium, endotracheal intubation, moderate hyperventilation (PaCO2 30-35 mmHg) without PEEP. Half (21) of the patients (group 1) were ventilated with O2/N2 (1:1) and the remaining patients (group 2) with O2/N2O (1:1). Heart rate (HR) arterial blood pressure (AP), central venous pressure (CVP), end-tidal CO2 tension (PE'CO2), and body temperature were monitored continuously. Arterial blood gases were checked once per hour at least. VAE was signaled by changes in the ultrasonic Doppler sounds or a rapid decrease in the end-tidal CO2 tension. The diagnosis of VAE was confirmed by aspirating air bubbles through the right atrial catheter. A vacuum-driven device was used to suction off the embolized air and measure the aspirated air volume. Pulmonary gas exchange was defined by the arterial to end-tidal CO2 difference (PaCO2 - PE'CO2) and by the alveolar arterial O2 quotient (PAO2 - PaO2/PAO2). If a VAE was recognized N2O administration was stopped immediately and ventilation was continued with pure oxygen. Postoperatively all patients were ventilated. ⋯ The incidence of VAE was similar in both groups: VAE occurred in five patients in group 1 and in six patients in group 2. In isolated cases distinct increases in the CO2 difference (PaCO2 - PE'CO2) or the O2 quotient (PAO2 - PaO2/PAO2) resulted, with no significant difference between the groups. In patients with VAE the aspirated gas volume (median 6.0 ml in group 1, 75.5 ml in group 2; P less than 0.01) and the duration of aspiration (median 5.0 min in group 1, 22.5 min in group 2; P less than 0.05) were significantly different in the two groups. HR was significantly lower in group 2 1 and 4 h after the beginning and at the end of the operation. MAP was significantly lower in group 2 3 and 4 h after the beginning and at the end of the operation. CVP was significantly higher in group 2 3 h after the start of the operation. The total dose of fentanyl, flunitrazepam and droperidol administered was higher in group 1 than in group 2 (P less than 0.05). The duration of postoperative ventilation was similar in both groups.(ABSTRACT TRUNCATED AT 400 WORDS)