The Journal of international medical research
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To test whether the cerebral state index (CSI) can be used as a measurement of the level of consciousness in unsedated brain-injured patients, 21 brain-injured adults were prospectively assessed in 77 separate sessions. After CSI monitoring was set up, the patient's motor responses to verbal and/or painful stimuli were assessed. CSI values were recorded before and after external stimulation. ⋯ Mean maximal CSI values increased significantly after external stimulation: from 71 to 89 and 49 to 62 in patients exhibiting purposeful and non-purposeful movements, respectively. The CSI value showed a high prediction probability (P(K) > 0.8) for detecting purposeful movement to external stimuli, especially after external stimulation (P(K) > 0.9). These results suggest that CSI monitoring might be a valid method for detecting purposeful movement in response to external stimuli in unsedated brain-injured patients.
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This study evaluated the correlation and agreement between the Bispectral Index (BIS) or A-line Autoregressive Index (AAI) and a clinical scoring system, the Ramsay Sedation Scale (RSS), in 40 patients after elective cardiac surgery and admission to the intensive care unit. All patients received sedation with propofol according to the study protocol. BIS, AAI and RSS were documented at two different levels of sedation: deep sedation RSS 4 - 6; and slight sedation/extubation RSS 2 - 3. ⋯ The systems agreed well among each other (overall intra-class correlations of 0.670 for consistency and 0.676 for absolute agreement). There was significant discrimination between RSS 2 - 3 and RSS 4 - 6 with BIS and AAI (BIS mean difference of 24.73, 95% confidence intervals [CI] 21.08 - 28.37; AAI mean difference of 20.90, 95% CI 14.64 - 27.16). In conclusion, BIS and AAI correlated well with RSS overall and also at different levels of sedation.
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Orexin-A is a neuropeptide involved in the regulation of food intake and the sleep-wake cycle. This study investigated plasma orexin-A levels in a sleep clinic cohort, adjusting for smoking habits, in 76 participants comprising 41 with obstructive sleep apnoea (OSA) (apnoea-hypopnoea index [AHI] 44.1 +/- 19.1 events/h) and 35 without OSA (AHI 6.3 +/- 4.7 events/h). ⋯ A significant inverse relationship was found between plasma orexin-A levels and AHI amongst never smokers, but there was no significant relationship amongst ex/current smokers. These results confirm previous studies demonstrating lower levels of plasma orexin-A in OSA patients and indicate that smoking may affect orexin-A levels and AHI.
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Controlled Clinical Trial
The effects of midazolam on the bispectral index after fetal expulsion in caesarean section under general anaesthesia with sevoflurane.
The effects of midazolam used with low concentration inhaled anaesthetics on the bispectral index (BIS) was investigated after fetal expulsion during caesarean section. Forty-five patients undergoing caesarean section received either normal saline (control, n = 15), or an intravenous bolus of 0.03 mg/kg (n = 15) or 0.05 mg/kg (n = 15) midazolam. ⋯ BIS values in the group that received 0.05 mg/kg midazolam were significantly lower than in the other two groups at 3, 5 and 10 min after fetal expulsion, and at subcutaneous tissue closure and skin closure. Values of BIS < 60 could only be maintained with 0.05 mg/kg midazolam and there was no delay in maternal emergence or recovery.
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Acute lung injury (ALI) frequently occurs in infants after cardiopulmonary bypass (CPB) surgery and it sometimes develops into acute respiratory distress syndrome in critically ill infants, which can be life threatening. This study investigated the effects of open lung ventilation on the haemodynamics and respiratory mechanics of 64 infants (34 males; 30 females) with a mean +/- SD age of 8.3 +/- 0.3 months who developed ALI following CPB surgery. Open lung ventilation significantly improved the respiratory mechanics and oxygenation parameters of the infants, including the partial pressure of oxygen in arterial blood (PaO(2)), the ratio of PaO(2)/FiO(2) (fraction of inspired oxygen), peak inspiratory pressure, static compliance and airway resistance. It is concluded that open lung ventilation can greatly improve oxygenation and respiratory mechanics in infants with ALI following CPB surgery.