British journal of anaesthesia
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Randomized Controlled Trial
Differential role of nitric oxide in the psychedelic symptoms induced by racemic ketamine and esketamine in human volunteers.
Animal studies suggest that N-methyl-d-aspartate receptor (NMDAR) hypofunction and subsequent decline in intracellular nitric oxide (NO) are responsible for development of ketamine-induced psychedelic symptoms. To examine this mechanism in humans, we administered the NO donor sodium nitroprusside during infusion of racemic ketamine (RS-ketamine), containing equal amounts of S(+)- and R(-)-ketamine isomers, or esketamine, containing just the S(+)-isomer. ⋯ NTR 5359.
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Methoxyflurane delivered via a hand-held inhaler is a proven analgesic which has been used in Australasia for emergency relief of trauma associated pain since the 1970s. The agent is self-administered by the patient under the supervision of trained personnel. More than 5 million patients have received inhaled methoxyflurane without significant side effects. ⋯ Thus, methoxyflurane may be a suitable and well-tolerated alternative to traditional i.v. sedative agents for outpatient medical and surgical procedures. There are direct advantages to the patient in terms of rapid recovery and an early return to normal activities, and significant benefits for outpatient departments in terms of cost saving and rate of throughput. Further randomised controlled trials comparing the efficacy, safety, and cost-effectiveness of inhaled methoxyflurane against traditional i.v. sedative techniques are currently in progress.
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Atomised intranasal dexmedetomidine administration is an attractive option when sedation is required for paediatric diagnostic procedures, as vascular access is not required. The risk of haemodynamic instability caused by dexmedetomidine necessitates better understanding of its pharmacokinetics in young children. To date, intranasal dexmedetomidine pharmacokinetics has only been studied in adults. ⋯ Mean arterial plasma concentrations of dexmedetomidine in infants and toddlers approached 100 pg ml-1, the low end reported for sedative efficacy, within 20 min of an atomised intranasal administration of 1 μg kg-1. Doubling the dose to 2 μg kg-1 reached this plasma concentration within 10 min and achieved almost twice the peak concentration. Peak plasma concentrations with both doses were reached within 47 min of intranasal administration, with an overall bioavailability of 84%.
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Intranasal dexmedetomidine produces safe, effective sedation in children and adults. It may be administered by drops from a syringe or by nasal mucosal atomisation (MAD NasalTM). ⋯ HKUCTR-1617.
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Comparative Study Observational Study
Use of prothrombin complex concentrate for management of coagulopathy after cardiac surgery: a propensity score matched comparison to plasma.
An important cause of coagulopathy in cardiac surgery is impaired thrombin generation. While plasma is often used to correct this element of the coagulopathy, studies in vitro suggest that prothrombin complex concentrates (PCCs) might be more effective. Comparative data, however, are scant. ⋯ Our exploratory study suggests that the use of PCCs as part of a multifaceted coagulation management strategy may have blood-sparing effects. Their incorporation into clinical practice, however, must await determination of their risk-benefit profile via multicentre randomised trials.