Anaesthesia
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Randomized Controlled Trial
The effect of high-flow nasal oxygen on hospital length of stay in cardiac surgical patients at high risk for respiratory complications: a randomised controlled trial.
There has been increased interest in the prophylactic and therapeutic use of high-flow nasal oxygen in patients with, or at risk of, non-hypercapnic respiratory failure. There are no randomised trials examining the efficacy of high-flow nasal oxygen in high-risk cardiac surgical patients. We sought to determine whether routine administration of high-flow nasal oxygen, compared with standard oxygen therapy, leads to reduced hospital length of stay after cardiac surgery in patients with pre-existing respiratory disease at high risk for postoperative pulmonary complications. ⋯ High-flow nasal oxygen was also associated with fewer intensive care unit re-admissions (1/49 vs. 7/45; p = 0.026). When compared with standard care, prophylactic postoperative high-flow nasal oxygen reduced hospital length of stay and intensive care unit re-admission. This is the first randomised controlled trial examining the effect of prophylactic high-flow nasal oxygen use on patient-centred outcomes in cardiac surgical patients at high risk for postoperative respiratory complications.
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Randomized Controlled Trial Comparative Study
A comparison of two techniques for induction of anaesthesia with target-controlled infusion of propofol.
Induction of anaesthesia with target-controlled infusion of propofol may be achieved by stepwise increases in effect-site concentration until the patient loses consciousness (titration method), or by setting a high effect-site concentration target and observing the calculated effect-site concentration at loss of consciousness (standard method). When the estimated effect-site concentration at loss of consciousness is accurate, the difference between effect-site concentration at loss of consciousness and at recovery of consciousness should be small. This prospective, randomised, controlled trial was designed to compare this difference (effect-site concentration at loss of consciousness - effect-site concentration at recovery of consciousness) associated with the two techniques. ⋯ The median (IQR [range]) difference between effect-site concentration at loss of consciousness and recovery of consciousness was significantly lower in patients in the titration group at 1.2 (0.8-1.5 [0.1-2.9]) μg.ml-1 compared with the standard group 2.1 (1.9-2.6 [0.2-3.6] μg.ml-1 ; p < 0.0001). There was a positive correlation between effect-site concentration at loss of, and recovery of, consciousness (R = 0.41, p = 0.016) in the titration group, which was not seen in the standard group (R = -0.15, p = 0.44). In conclusion, using the modified Marsh pharmacokinetic model, the titration method for target-controlled infusion propofol at induction of anaesthesia allows closer matching of propofol concentration to depth of anaesthesia than the standard method.
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Randomized Controlled Trial
A novel, palatable paediatric oral formulation of midazolam: pharmacokinetics, tolerability, efficacy and safety.
Midazolam is one of many bitter drugs where provision of a suitable oral paediatric formulation, particularly in the pre-anaesthetic setting, remains a challenge. To overcome this problem, a novel chocolate-based tablet formulation has been developed with positive pre-clinical results. To further investigate the potential of this formulation, 150 children aged 3-16 years who were prescribed midazolam as a premedication were randomly assigned to receive 0.5 mg.kg-1 either as the novel formulation or an intravenous solution given orally, which is the current standard at our institution. ⋯ The novel formulation was subject to a higher estimated first-pass metabolism compared with the intravenous solution (8.6% vs. 5.0%) and a significantly lower relative bioavailability of 82.1% (p = 0.013), with no other significant differences. Exposure relative to dose was in the range previously reported for midazolam syrup. We conclude that the novel chocolate-based formulation of midazolam provides improved tolerability while remaining efficacious with suitable pharmacokinetics when used as a premedicant for children.
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Randomized Controlled Trial
Volume of ropivacaine 0.2% and common peroneal nerve block duration: a randomised, double-blind cohort trial in healthy volunteers.
The volume-duration relationship using low concentrations of ropivacaine for peripheral nerve blocks is unknown, even though low concentrations of ropivacaine are increasingly used clinically. We investigated the effect of ropivacaine 0.2% on common peroneal nerve block duration. With ethical committee approval, 60 consenting, healthy volunteers were randomly allocated to receive one of five volumes of ropivacaine 0.2% (2.5, 5.0, 10, 15 or 20 ml) administered by ultrasound-guided, catheter-based injection (at 10 ml.min-1 ) near the common peroneal nerve. ⋯ Mean (SD) motor block durations were 3.3 (2.1), 7.2 (2.5), 9.2 (2.2), 12.7 (2.5) and 12.5 (2.5) h. Regression analysis showed that the effect of volume on block duration was progressively smaller with increasing volume, reaching a threshold volume above which there was no effect on nerve block duration (10 ml for sensory block and 15 ml for motor block). We conclude that there is a ceiling effect of increasing volume of ropivacaine 0.2% on both sensory and motor block duration of the common peroneal nerve.
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Randomized Controlled Trial
Effect of a single pre-operative 125 mg dose of methylprednisolone on postoperative delirium in hip fracture patients; a randomised, double-blind, placebo-controlled trial.
Postoperative delirium is common after hip fracture surgery, and may have a neuro-inflammatory cause. We conducted a single-centre, randomised, double-blind, placebo-controlled trial of 117 older hip fracture patients to see if a single, pre-operative intravenous dose of 125 mg methylprednisolone could reduce the severity and/or incidence of postoperative delirium, assessed using the Confusion Assessment Method delirium severity score. Modified intention-to-treat analysis found no significant difference in our primary outcome, median (IQR [range]) cumulative Confusion Assessment Method delirium severity score over the first three postoperative days between the methylprednisolone and placebo groups (1 (0-6 [0-39]) vs. 2 (0-10 [0-32]), p = 0.294). ⋯ There were no significant between-group differences in the rate of completing physiotherapy, postoperative pain, the administration of antipsychotic drugs, infection, length of inpatient stay or 30- and 90-day mortality. No major adverse reactions related to methylprednisolone were recorded. We conclude that a single, pre-operative dose of 125 mg methylprednisolone does not reduce the severity of postoperative delirium, but may reduce both the prevalence of delirium and the severity of fatigue after hip fracture surgery in older patients, enabling remobilisation and recovery.