Anaesthesia and intensive care
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Anaesth Intensive Care · Jan 2015
Clinical predictors of a low central venous oxygen saturation after major surgery: a prospective prevalence study.
Optimising perioperative haemodynamic status may reduce postoperative complications. In this prospective prevalence study, we investigated the associations between standard haemodynamic parameters and a low central venous oxygen saturation (ScvO2) in patients after major surgery. A total of 201 patients requiring continuous arterial and central venous pressure monitoring after major surgery were recruited. ⋯ Use of mechanical ventilation, mean arterial pressure, central venous pressure, haemoglobin concentrations, arterial pH and lactate concentrations, arterial oxygen (PaO2) and carbon dioxide tensions (PaCO2) were all associated with a low ScvO2 in the univariate analyses. In the multivariate analysis, only a higher perfusion index (odds ratio [OR] 0.87, 95% confidence interval [CI] 0.78 to 0.98), PaO2 (OR 0.98 per mmHg increment, 95% CI 0.97 to 0.99) and PaCO2 (OR 0.88 per mmHg increment, 95% CI 0.82 to 0.95) and a lower central venous pressure (OR 1.14 per mmHg increment, 95% CI 1.04 to 1.25) were significantly associated with a reduced risk of a low ScvO2, all in a linear fashion. In conclusion, PaO2, PaCO2, perfusion index and central venous pressure were significant predictors of a low ScvO2 in patients after major surgery including cardiac surgery.
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Anaesth Intensive Care · Jan 2015
The time taken for the regional distribution of ventilation to stabilise: an investigation using electrical impedance tomography.
Electrical impedance tomography is a novel technology capable of quantifying ventilation distribution in the lung in real time during various therapeutic manoeuvres. The technique requires changes to the patient's position to place the electrical impedance tomography electrodes circumferentially around the thorax. The impact of these position changes on the time taken to stabilise the regional distribution of ventilation determined by electrical impedance tomography is unknown. ⋯ Left-right stabilisation was achieved after 15 minutes in Fowler's position and supine. A minimum of 15 minutes of stabilisation should be allowed for spontaneously breathing individuals when assessing ventilation distribution. This time allows stabilisation to occur in the anterior-posterior direction as well as the left-right direction.
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Anaesth Intensive Care · Jan 2015
Minimum effective anaesthetic volume of 0.5% ropivacaine for ultrasound-guided popliteal sciatic nerve block in patients undergoing foot and ankle surgery: determination of ED50 and ED95.
Compared to nerve stimulation or classic paraesthesia techniques, ultrasound (US)-guided popliteal sciatic nerve block requires a smaller volume of local anaesthetic. The up-and-down method was used to determine the minimum effective anaesthetic volume of 0.5% ropivacaine necessary for US-guided popliteal sciatic nerve block to achieve successful surgical anaesthesia for foot and ankle surgery. The study included 32 patients receiving an US-guided popliteal sciatic nerve bock. ⋯ The success rates of sensory blockade of the tibial nerve and common peroneal nerve were 69% and 88%, respectively. The success rates of motor blockade of these nerves were 75% and 90%, respectively. The ED50 and ED95 of 0.5% ropivacaine for US-guided popliteal sciatic nerve block were 6 ml and 16 ml, respectively.
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Anaesth Intensive Care · Jan 2015
A retrospective survey of substance abuse in anaesthetists in Australia and New Zealand from 2004 to 2013.
A questionnaire on substance abuse was distributed electronically to the heads of 185 Australian and New Zealand College of Anaesthetists accredited anaesthesia departments in Australia and New Zealand. The response rate was 57%. From January 2004 to December 2013, 61 cases of substance abuse were identified, giving an estimated incidence of 1.2 cases per 1000 anaesthetist years. ⋯ Death was the eventual outcome in 18% overall, with a particularly high mortality associated with propofol abuse (45%). Trainee suicide from all causes was reported at three times the rate of specialists. The findings indicate that substance abuse remains a significant problem in Australia and New Zealand and is associated with a significant mortality rate.