British journal of anaesthesia
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Randomized Controlled Trial Clinical Trial
Age- and therapy-related effects on morphine requirements and plasma concentrations of morphine and its metabolites in postoperative infants.
To investigate clinical variables such as gestational age, sex, weight, the therapeutic regimens used and mechanical ventilation that might affect morphine requirements and plasma concentrations of morphine and its metabolites. ⋯ Neonates have a narrower therapeutic window for postoperative morphine analgesia than older age groups, with no difference in the safety or effectiveness of intermittent doses compared with continuous infusions in any of these age groups. In infants >1 month of age, analgesia is achieved after morphine infusions ranging from 10.9 to 12.3 micro g kg(-1) h(-1) at plasma concentrations of <15 ng ml(-1).
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Randomized Controlled Trial Clinical Trial
Relationship between awareness and middle latency auditory evoked responses during surgical anaesthesia.
Some studies support the view that meaningful auditory input can be processed by the brain during apparent surgical anaesthesia. Consequently, patients may be able to remember some information implicitly after anaesthesia as well through a 'dream-like process' (subconscious awareness). The aim of this study was to investigate the presence of subconscious awareness during anaesthesia and to examine its relationship to the mid-latency auditory evoked responses (MLAERs). ⋯ MLAERs may help to predict subconscious cerebral processing of auditory inputs during anaesthesia.
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The crucial role of L-type Ca(2+) channels in airway smooth muscle contraction suggests that these channels could be an important therapeutic target. There are three separate drug binding sites on this channel: those for dihydropyridines, benzothiazepines and phenyl alkylamines. In this study, we examined the effects of the dihydropyridines nifedipine and nicardipine, the benzothiazepine diltiazem, and the phenylalkylamine verapamil on airway constriction. ⋯ Although supraclinical doses of dihydropyridines and benzothiazepines can produce airway relaxant effects, these agents are unlikely to be used in the treatment of bronchoconstriction. In addition, verapamil may aggravate airway constriction.
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Case Reports
Detection of cerebral hypoperfusion with bispectral index during paediatric cardiac surgery.
The bispectral index (BIS) may indicate changes in cerebral activity when the cerebral circulation is affected by acute hypotension. ⋯ Our findings suggest that an acute decrease in BIS during acute hypotension indicates cerebral hypoperfusion, and that cerebral hypoperfusion caused by hypotension may occur frequently during paediatric cardiac surgery.