Der Anaesthesist
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The Christiansen-Douglas-Haldane effect describes the reduced CO2 binding capacity of oxygenated compared to deoxygenated haemoglobin. Under the condition of a "closed system", for example hyperoxic apnoea after adequate preoxygenation (continuous O2 uptake with lack of CO2 delivery), specific effects on the arterial and mixed venous blood gas status, due to the Haldane effect, are seen: within 30 s after onset of apnoea, "paradoxical pCO2" (paCO2 exceeds pvCO2) and "pH reversal" (pHa falls under pHv) can be observed. It was the aim of this study to demonstrate how fast arterial and mixed venous pCO2 and pH normalize when a change from apnoea ("closed system") to controlled ventilation ("open system") takes place. ⋯ Considering the expected decrease of paO2 during hyperoxic apnoea, insufficient pulmonary N2 elimination prior to the onset of apnoea, as well as direct N2 delivery into the alveoli, due to the so-called a ventilatory mass flow, will limit unrestricted pulmonary O2 uptake. The continuing decrease of the paCO2 after the onset of controlled ventilation can be regarded as indirect proof of a ventilatory mass flow. The course of pCO2 and pH after the onset of controlled ventilation shows that normalization in arterial and mixed-venous blood gas status takes place in about 18.2 s after the cessation of apnoea.
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At present the in vitro caffeine-halothane contracture test is the only test to predict susceptibility to malignant hyperthermia (MH) with acceptable sensitivity and specificity. Anaesthesia is necessary for the excision of muscle bundles from the vastus lateralis muscle. MATERIAL AND METHODS. ⋯ Complete monitoring is necessary, even for this minor procedure: ECG, blood pressure, pulse oximetry, capnometry, measurement of body temperature and blood gas status. Differential diagnosis in negative test results. In patients who suffer an anaesthetic incident, the following disease must be considered: myopathies (especially the congenital myopathies and muscular dystrophies), respiratory problems due to pulmonary infection and obstruction, metabolic disorders of various origins, and the problem of masseter spasm.
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Oximetric measurements are influenced by several mechanisms. Severe jaundice is one of these mechanisms with some clinical interest. In the literature it is pointed out that a high bilirubin concentration may falsify oximetric measurements and is often accompanied by elevated COHb levels. ⋯ With increasing bilirubin levels the MetHb concentration measured with the CO 2500 rises, while the OSM3 gives constant MetHb values. 5. In severe jaundice the O2Hb values measured with multiwavelength oximeters are not identical with the real blood concentration of this haemoglobin derivative. In this situation multiwavelength oximeters cannot be used as a reference method for in vivo oximetric systems such as pulse oximeters or fibreoptic pulmonary artery catheters.
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Randomized Controlled Trial Clinical Trial
[Recovery of psychomotor and cognitive functions following anesthesia. Propofol/alfentanil and thiopental/isoflurane/ alfentanil].
Recent changes in the medical system have resulted in a significant increase of ambulatory surgical procedures. Therefore, a safe and short postoperative recovery period and, especially, the full recovery of complex psychological function after general anaesthesia have become increasingly important. In the present study we investigated the recovery of psychomotor and cognitive function after general anaesthesia with propofol/alfentanil and thiopentone/isoflurane/alfentanil. ⋯ Also in the digit span, the scores were significantly lower 30 min after recovery from the anaesthetic. Here again the propofol group tended to be a little better than the isoflurane group 30 min, 60 min and 240 min after anaesthesia. In the Munich Verbal Learning Test both groups had lower scores 30 min and 60 min, the isoflurane group also 240 min, after recovery...
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Although the incidence of difficult airway is very low, involving less than 1% of all patients, failed air-way management is the main cause of mortality or serious morbidity during anaesthesia. Successful management of a difficult airway starts with recognition of the potential problem. A careful preoperative history and clinical examination should elicit obvious problems to allow prediction of a potentially difficult airway. ⋯ The LMA is a new device developed to provide an airway for anaesthesia. However, since the LMA can be inserted quickly and blind, it can be used as an alternative airway in patients in whom the trachea is difficult to intubate. The lower incidence of post-operative complications than with endotracheal intubation is a further advantage, particularly during anaesthesia for day surgery.