Der Anaesthesist
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Randomized Controlled Trial Comparative Study Clinical Trial
[Comparison of postoperative volume therapy in heart surgery patients].
Patients who have undergone cardiac surgery with use of extracorporeal circulation frequently reveal marked hypovolaemia in spite of a highly positive fluid balance. This is thought to be due to transient microvascular damage and extravascular fluid shift. Further volume replacement to achieve haemodynamic stability in the postoperative period may cause fluid overload and congestive heart failure. The present study was designed to investigate whether this fluid overload could be avoided by using a hypertonic-hyperoncotic solution (group I: HHL, 10% hydroxyethylstarch 200/0.5 in 7.2% saline) instead of two different standard colloid solutions (group II: HA, 5% albumin; group III: HES, 6% hydroxyethylstarch in 0.9% saline). ⋯ We found that HHL is a safe and effective solution for acute correction of hypovolaemia after cardiac surgery. The advantages of a smaller initial volume load by HHL cannot be maintained for longer than 2 h.
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Pulse contour cardiac output (PCCO) is an easily applicable method for continuous measurement of cardiac output in critically ill patients. Calculation of stroke volume is possible by analysing the area under the systolic part of the arterial pulse pressure waveform together with an individual calibration factor (Zao) to account for the individually variable vascular impedance. Since vascular impedance is potentially affected by altered vascular tone, it was the aim of the present study to examine the validity of PCCO in ICU patients receiving various dosages of a variety of vasoactive drugs. ⋯ Alteration of vascular tone by clinically used dosage of vasoactive drugs, however, had no destabilizing effect on the pulse contour method. CONCLUSIONS. It could be demonstrated that PCCO provides a valuable method for continuous cardiac output measurement in the intensive care setting with a precision comparable to that of thermodilution.
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The use of autotransfusion devices is an established method of reducing the need for homologous transfusions in surgery [3, 11, 13], but technical factors still contraindicate the washing and concentration of blood volumes smaller than 300 ml. Therefore, haemoconcentration of small volumes of salvaged blood, as usually found in paediatric surgery, is considered to be a complicated and questionable practice [5]. Whereas these amounts of blood loss are easily tolerated by adults, they may necessitate homologous transfusions in paediatric surgery. ⋯ CONCLUSIONS. This study shows that the use of blood salvaging in paediatric surgery is indicated under certain conditions. With the aid of the simple modification described above, we solved the main problem in paediatric autotransfusion by concentrating RBC suspensions with low Hb and Hct values after using the autotransfusion device.
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The conventional multichannel electroencephalogram is quite inconvenient for long-term monitoring in the operating theatre or intensive care unit. Recording of the EEG would be easier if a small number of channels was sufficient. Aiming at reduction of channels, leads from different regions of the scalp were analysed visually and with regard to their spectral content. ⋯ For the choice of an appropriate set of channels the following aspects should be considered. Contamination with artifacts should be as low as possible, electrode sites should easily be accessible, and special features of the awake state should be identifiable. Experience with routinely conducted EEG recordings in the operating theatre and the intensive care unit showed that the channels C3-P3 or C4-P4 provide a sufficient basis for automatic staging of the depth of anaesthesia, which is implemented in the EEG monitor Narkograph.