British journal of anaesthesia
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It is believed that the severely disturbed night-time sleep architecture after surgery is associated with increased cardiovascular morbidity with rebound of rapid eye movement (REM). The daytime sleep pattern of patients after major general surgery has not been investigated before. We decided to study the circadian distribution of sleep phases before and after surgery. ⋯ Patients have significantly increased REM sleep, LS, and reduced time awake during the daytime period after surgery compared with before surgery. Disturbances in the circadian regulation of the sleep-wake cycle may be involved in the development of postoperative sleep disturbances.
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The relationship between measures of drug effect such as bispectral index (BIS) and end-tidal (ET) levels of anaesthetic agents is described by the 'effect site equilibrium half-time', t(1/2)(ke0). There are limited data available on sevoflurane t(1/2)(ke0) during routine anaesthesia and surgery. Preliminary observations suggested t(1/2)(ke0) for the degree of hypnosis as estimated by BIS is different from that for burst suppression of the electroencephalograph, occurring at 'deep' levels of anaesthesia. This study aimed to determine and compare t(1/2)(ke0) for these two 'effects'. ⋯ The different values of t(1/2)(ke0) for these effects suggest different sites or mechanisms of action. These results also establish values of t(1/2)(ke0) which can be used to provide the real-time estimates of effect-site sevoflurane concentration in clinical practice.
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Large quantities of water condensation occur in the anaesthesia circuit during low-flow anaesthesia. We hypothesized that cooling of the CO2 absorbent would prevent water condensation. ⋯ TGR of CO2 absorbent with cooling is a useful and simple method to reduce water condensation in the anaesthesia circuit in low-flow anaesthesia, with a little increase in the longevity of the CO2 absorbent.
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The purpose of this study was to evaluate the agreement of cardiac output measurements obtained by electrical velocimetry (CO(EV)) and those that derived from the direct Fick-oxygen principle (CO(F)) in infants and children with congenital heart defects. ⋯ CO(EV) demonstrates acceptable agreement with data derived from CO(F) in infants and children with congenital heart disease. The new technique is simple, completely non-invasive, and provides beat-to-beat estimation of CO.
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We tested the hypothesis that sodium nitroprusside (SNP) might improve the impairment of hepatosplanchnic microcirculatory blood flow (MBF) in septic shock. ⋯ In a resuscitated porcine model of the early phase of septic shock, SNP improved ileal mucosal MBF but required a concomitant increase in fluid and norepinephrine supplements to maintain constant systemic haemodynamic parameters.