Acta anaesthesiologica Scandinavica
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Acta Anaesthesiol Scand · Aug 2012
Pleural effusion decreases left ventricular pre-load and causes haemodynamic compromise: an experimental porcine study.
Although pleural effusion is a common complication in critically ill patients, detailed knowledge is missing about the haemodynamic impact and the underlining mechanisms. The aim of this study was to evaluate the haemodynamic effect of incremental pleural effusion by means of invasive haemodynamic parameters and transthoracic echocardiography. ⋯ Incremental volumes of unilateral pleural effusion induced a significant haemodynamic impact fully reversible after drainage. Pleural effusion causes a significant decrease of left ventricular pre-load in a diverse picture of haemodynamic compromise.
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Acta Anaesthesiol Scand · Aug 2012
Clinical TrialHigh-resolution MRI demonstrates detailed anatomy of the axillary brachial plexus. A pilot study.
Axillary block is the most commonly performed brachial plexus block and may be guided by nerve stimulation or ultrasound. Magnetic resonance imaging (MRI) has proven to be beneficial in presenting anatomy of interest for regional anaesthesia and in demonstrating spread of local anaesthetic. The aim of this pilot study was to demonstrate the anatomy as shown by MRI of the brachial plexus in the axillary region. ⋯ Clinical high-field 3.0 Tesla MRI scanner gives good visualization of brachial plexus in the axilla. The superior ability to detect local anaesthetics after it has been injected and the multiplanar imaging capability make MRI a useful tool in studies of the brachial plexus.
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Acta Anaesthesiol Scand · Aug 2012
Oxygen transport and mitochondrial function in porcine septic shock, cardiogenic shock, and hypoxaemia.
The relevance of tissue oxygenation in the pathogenesis of organ dysfunction during sepsis is controversial. We compared oxygen transport, lactate metabolism, and mitochondrial function in pigs with septic shock, cardiogenic shock, or hypoxic hypoxia. ⋯ We conclude that despite shock and renal hypoperfusion, tissue hypoxia is not a major pathophysiological issue in early and established faecal peritonitis. The reasons for reduced skeletal muscle tissue ATP levels in the presence of well-preserved in-vitro muscle mitochondrial respiration should be further investigated.
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Acta Anaesthesiol Scand · Aug 2012
Measuring the effects of sevoflurane on electroencephalogram using sample entropy.
Monitoring the effect of anesthetic drugs on the neural system is a major ongoing challenge for anesthetists. During the past few years, several electroencephalogram (EEG)-based methods such as the response entropy (RE) as implemented in the Datex-Ohmeda M-Entropy Module have been proposed. In this paper, sample entropy is used to quantify the predictability of EEG series, which could provide an index to show the effect of sevoflurane anesthesia. The dose-response relation of sample entropy is compared with that of RE. ⋯ The results demonstrate that sample entropy can estimate the sevoflurane drug effect on the EEG more effectively than the commercial RE index with a stronger noise resistance.
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Acta Anaesthesiol Scand · Aug 2012
Review Meta AnalysisVasopressors for the management of hypotension after spinal anesthesia for elective caesarean section. Systematic review and cumulative meta-analysis.
Phenylephrine use has been recommended over ephedrine for the management of hypotension after spinal anesthesia for elective caesarean section. The evidence for this is rather limited because in previous trials, pH was significantly lower after ephedrine, but absolute values were still within normal range. We pooled the available data to define maternal and neonatal effects of the two vasopressors. ⋯ Our analysis could clearly demonstrate a decreased risk of fetal acidosis associated with phenylephrine use. In addition with our findings for BE, this suggests a favorable effect of phenylephrine on fetal outcome parameters. The mechanism of pH depression is not related to pCO(2) .