Anaesthesia
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Randomized Controlled Trial
Cerebral oximetry and postoperative delirium after cardiac surgery: a randomised, controlled trial.
Postoperative delirium is associated with increased morbidity and mortality. We hypothesised that restoration of regional cerebral oxygen desaturation would reduce the incidence of postoperative delirium in elderly patients after cardiac surgery. After institutional ethics review board approval and informed consent, a double-blinded, prospective, randomised, controlled trial was conducted in patients ≥ 60 years of age undergoing cardiac surgery with cardiopulmonary bypass. ⋯ Higher baseline regional cerebral oxygen saturation and body mass index were protective against postoperative delirium. Restoration of regional cerebral oxygen desaturation did not result in lower postoperative delirium after cardiac surgery. Pre-operative regional cerebral oxygen saturation ≤ 50% was associated with increased postoperative delirium rates in elderly patients following cardiac surgery.
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Randomized Controlled Trial
The effect of acetazolamide on intra-ocular pressure after Trendelenburg positioning - a randomised double-blind crossover trial in volunteers.
Recent evidence suggests Trendelenburg positioning can produce a significant rise in intra-ocular pressure. Peri-operative vision loss in patients undergoing laparoscopic colorectal surgery has been reported with the rise in intra-ocular pressure suggested as a possible factor. Acetazolamide decreases intra-ocular pressure by reducing the formation of aqueous humour, so we aimed to investigate if it could attenuate the intra-ocular pressure rise that can occur in the Trendelenburg position. ⋯ There were two males and seven female volunteers, with a mean (SD) age of 54.3 (18.5) years. The mean (SD) increase in intra-ocular pressure following 4 h in the Trendelenburg position was 3.17 (4.63) mmHg after the placebo, and 0.02 (4.01) mmHg (p = 0.02) after acetazolamide. We have shown than acetazolamide can attenuate the rise that occurs in intra-ocular pressure when in the Trendelenburg position.
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Randomized Controlled Trial Comparative Study
Dynamic ultrasound-guided short-axis needle tip navigation technique vs. landmark technique for difficult saphenous vein access in children: a randomised study.
Dynamic ultrasound-guided short-axis needle tip navigation is a novel technique for vascular access. After venipuncture, the needle and catheter are further advanced within the vessel lumen under real-time ultrasound guidance with constant visualisation of the needle tip in the short-axis view. This can minimise the risk of transfixing the cannulated vessel. ⋯ First-attempt success rate was 90% in the ultrasound group compared with 51% in the landmark group, p<0.001, difference 39%, 95% confidence interval (CI) of the difference 23-55%. Success rate within 10 min was 92% in the ultrasound group compared with 63% in the landmark group, p = 0.001, difference 29%, 95%CI of the difference 14-45%. We conclude that, when performed by experienced anaesthetists, the dynamic ultrasound-guided short-axis needle tip navigation technique improved non-visible saphenous vein cannulation in children compared with the landmark technique.
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Acute risk change has been described as the difference in calculated mortality risk between the pre-operative and postoperative periods of cardiac surgery. We aimed to assess whether this was associated with long-term survival after cardiac surgery. We retrospectively analysed 22,570 cardiac surgical patients, with minimum and maximum follow-up of 1.0 and 6.7 years. ⋯ Acute risk change may represent peri-operative clinical events in combination with unmeasured patient risk and noise. Measuring risk change could potentially identify patterns of events that may be amenable to investigation and intervention. Further work with case review, and risk scoring with shared variables, may identify mechanisms, including the interaction between miscalibration of risk and true differences in peri-operative care.
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Facemask ventilation of the lungs can be an important rescue intervention in a 'cannot intubate' scenario. We assessed the effect of neuromuscular blockade on expiratory tidal volumes in patients with expected difficulty in mask ventilation. The lungs of patients with at least three predictors of difficulty in mask ventilation were ventilated using a facemask held with two hands, with mechanical ventilation set in a pressure-controlled mode. ⋯ No decrease in the tidal volume during the measurements was observed. We conclude that the administration of rocuronium at a dose of 0.6 mg.kg-1 was able to improve facemask ventilation in all cases with a potentially clinically relevant increase in tidal volume. The early use of a neuromuscular blocking agent can be considered as a therapeutic option in case of difficulty with mask ventilation.