British journal of anaesthesia
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Ketamine has been shown to have neurotoxic properties, when administered neuraxially. The mechanism of this local toxicity is still unknown. Therefore, we investigated the mechanism of cytotoxicity in different human cell lines in vitro. ⋯ Ketamine at millimolar concentrations induces apoptosis via the mitochondrial pathway, independent of death receptor signalling. At higher concentrations necrosis is the predominant mechanism. Less toxicity of S(+)-ketamine was observed in neuroblastoma cells, but this difference was minor and therefore unlikely to be mediated via the NMDA receptor.
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Multicenter Study
Confirming the drugs administered during anaesthesia: a feasibility study in the pilot National Health Service sites, UK.
To help prevent drug errors, it is recommended that drugs should be confirmed/checked with a second person before administration. We aimed to assess the feasibility of introducing second-person or electronic bar-code confirmation of drugs, administered during anaesthesia, in the National Health Service (NHS) settings in the UK. ⋯ The introduction of two-person confirmation to the NHS would have a significant impact on the existing working practices. Issues related to resources and a cultural change will need to be addressed. Electronic confirmation was more feasible, but the technological aspects of its integration into the operating theatre environment, and learning, will require further attention.
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The value of respiratory variables as weaning predictors in the intensive care unit (ICU) is controversial. We evaluated the ability of tidal volume (Vt(exp)), respiratory rate (f), minute volume (MV(exp)), rapid shallow breathing index (f/Vt), inspired-expired oxygen concentration difference [(I-E)O(2)], and end-tidal carbon dioxide concentration (Pe'(co(2))) at the end of a weaning trial to predict early weaning outcomes. ⋯ In unselected ICU patients, respiratory variables predict early weaning from mechanical ventilation poorly.
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The loss of cholinergic neurones in the basal forebrain has been shown to correlate to the extent of cognitive dysfunction during ageing in humans and to the hypnotic potency of propofol in animal models. We examined how the preoperative cognitive status, as assessed by mini-mental state examination (MMSE), may interact with propofol consumption during anaesthesia in the elderly. ⋯ Propofol requirement to maintain hypnosis during general anaesthesia appears to decrease with deterioration in the cognitive status in the elderly. We suggest that a cognitive dysfunction linked to a cerebral cholinergic dysfunction may influence the brain sensitivity for propofol in aged patients.
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Pressure-controlled ventilation (PCV) has been suggested to reduce peak airway pressure (P(peak)) and intrapulmonary shunt during one-lung ventilation (OLV) when compared with volume-controlled ventilation (VCV). At the same tidal volume (V(T)), the apparent difference in P(peak) is mainly related to the presence of a double-lumen tracheal tube. We tested the hypothesis that the decrease in P(peak) observed in the breathing circuit is not necessarily associated with a decrease in the bronchus of the dependent lung. ⋯ During PCV for OLV, the decrease in P(peak) is observed mainly in the respiratory circuit and is probably not clinically relevant in the bronchus of the dependent lung. This challenges the common clinical perception that PCV offers an advantage over VCV during OLV by reducing bronchial P(peak).