British journal of anaesthesia
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Logistical and ethical reasons make conducting clinical research in paediatric practice difficult, and therefore safe and efficacious advances are dependent on good preclinical research. For example, notable advances have been made in preclinical studies of pain processing that correlate well with patient data. ⋯ The potential for this toxicity must be balanced against the importance of providing adequate anaesthesia for which there can be no compromise. We review the current state of preclinical research in paediatric anaesthesia and identify areas which require further exploration in order to provide the foundations for well-conducted clinical trials.
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Comparative Study
Validation of the index of consciousness during sevoflurane and remifentanil anaesthesia: a comparison with the bispectral index and the cerebral state index.
The purpose of this study was to validate a new level of consciousness monitor derived from the EEG, called the index of consciousness (IoC), by comparing it with the bispectral index (BIS) and the cerebral state index (CSI) during general anaesthesia for cardiac surgery using sevoflurane, remifentanil, and atracurium. ⋯ The three indices performed equally well during the induction phase and were able to predict the level of consciousness of the patients satisfactorily. During maintenance, the IoC and the BIS showed good agreement with the clinical signs. The CSI was significantly influenced by the administration of atracurium; therefore, the agreement with the OAAS scale during the maintenance phase was significantly less for CSI than for IoC and BIS.
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Propofol is mainly metabolized in the liver, but extrahepatic clearance may also be important since systemic propofol clearance exceeds hepatic clearance. Recent reports suggest that the kidneys contribute to propofol elimination in humans and here we investigated renal elimination of propofol in a controlled animal study. ⋯ The kidneys are a minor site of propofol elimination in a swine model.
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The management of patients with carcinoid heart disease poses two major challenges for the anaesthetist: carcinoid crisis and low cardiac output secondary to right ventricular (RV) failure. Carcinoid crises may be precipitated by the administration of catecholamines and histamine-releasing drugs. ⋯ Carcinoid crisis and RV failure still remain the primary challenges for the anaesthesiologist while managing patients with carcinoid heart disease. Our study supports the administration of catecholamines to wean patients off cardiopulmonary bypass, particularly in the presence of myocardial dysfunction. Those patients on higher octreotide dosages may require close intraoperative glucose monitoring. Despite high operative mortality, surgical outcome has been improved potentially due to earlier patient referral and better perioperative management.
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Hyperventilation, with the resulting hypocapnia, reduces cerebral blood flow and causes slowing of the EEG activity. However, neuronal oscillating properties including the thalamocortical network during hyperventilation have not been elucidated. To assess these features provoked by hyperventilation, the present study examined quadratic phase coupling features by means of bicoherence analysis. ⋯ Hypocapnia enlarged bicoherence growth in the delta- frequency range, suggesting the contribution of subcortical oscillating mechanisms in regulating EEG during hyperventilation.