Anaesthesia and intensive care
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Anaesth Intensive Care · May 2011
Randomized Controlled Trial Comparative StudyMyocardial injury in remifentanil-based anaesthesia for off-pump coronary artery bypass surgery: an equipotent dose of sevoflurane versus propofol.
This randomised controlled trial compared the effect of equipotent anaesthetic doses of sevoflurane (S group) versus propofol (P group), during remifentanil-based anaesthesia for off-pump coronary artery bypass surgery, on myocardial injury. Either sevoflurane or propofol was titrated to maintain bispectral index values between 40 and 50. In both groups, a targeted concentration of remifentanil 20 ng x ml(-1) was maintained during anaesthesia. ⋯ The postoperative values of creatine kinase MB (S group: 15.08 +/- 18.97, 20.78 +/- 20.92, 12.76 +/- 12.82 vs 2.09 +/- 1.54 ng x ml(-1); P group: 10.99 +/- 13.15 27.16 +/- 56.55 11.88 +/- 18.80 vs 1.84 +/- 1.67 ng x ml(-1)) and troponin I (S group: 3.56 +/- 5.19, 566 +/- 7.89, 3.35 +/- 4.55 vs 0.52 +/- 1.90 ng x ml(-1); P group: 2.42 +/- 3.33, 4.11 +/- 6.01, 3.04 +/- 5.31 vs 0.43 +/- 1.28 ng x ml(-1)) were significantly higher than preoperative values in both groups but there were no significant differences between the two groups. There were no significant differences in time to extubation (S group, 476 +/- 284 minutes; P group, 450 +/- 268 minutes) and intensive care unit length of stay (S group, 2775 +/- 1449 minutes; P group, 2797 +/- 1534 minutes) between the two groups. In conclusion, sevoflurane and propofol at equipotent doses guided by bispectral index with remifentanil 20 ng x ml(-1) had similar creatine kinase MB and troponin I values.
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Anaesth Intensive Care · May 2011
Randomized Controlled TrialMini-ventilation for improved oxygenation during lung resection surgery.
Lung separation is frequently used during lung resection to facilitate surgery and hypoxaemia may occur because of increasing pulmonary shunt. In this study, we tested a method of mini-ventilation to the non-dependent lung and compared it to continuous positive airway pressure (CPAP) to improve oxygenation during lung resection. Thirty-eight adult patients participated in this randomised, single-blinded crossover study. ⋯ The surgical conditions were similar with both methods in 53% of the patients, while the surgeon preferred CPAP in 44% and mini-ventilation in 3%. In conclusion, mini-ventilation is a simple method which improves oxygenation during lung resection. However due to interference with surgical field exposure, it should be reserved for cases in which CPAP does not relieve hypoxaemia.
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Anaesth Intensive Care · May 2011
Randomized Controlled TrialThe effect of the sitting upright or 'beachchair' position on cerebral blood flow during anaesthesia for shoulder surgery.
The sitting upright or 'beachchair' position is commonly used for shoulder arthroscopic surgery. There is a theoretical concern that anaesthetised patients placed in this posture are at risk of reduced cerebral blood flow (CBF), especially if there is associated hypotension. This study investigated the effect of anaesthetic-induced hypotension on estimated cerebral blood flow in patients placed in the beachchair position for shoulder surgery. ⋯ However, CBF remained constant in both anaesthetised (P = 0.83) and sedated patients (P = 0.68) despite beachchair positioning, and the fall in mean arterial pressure in the anaesthetised patients. There was no significant difference in CBF between groups (P = 0.91). These findings indicate that in patients in the beachchair position receiving sevoflurane anaesthesia, CBF is maintained when mean arterial pressure is above 70 mmHg, consistent with intact autoregulation.
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Anaesth Intensive Care · May 2011
Randomized Controlled TrialEffect of daily sedative interruption on sleep stages of mechanically ventilated patients receiving midazolam by infusion.
Daily sedative interruption (DSI) may reduce excessive sedation and shorten the duration of mechanical ventilation. It is not clear, however, how DSI affects sleep characteristics. For patients receiving mechanical ventilation, we compared the effect on sleep quality of DSI and continuous sedation (CS). ⋯ In the DSI group, the amount of stage 3 and 4 non-rapid eye movement sleep (slow wave sleep) was longer (6 vs 0 minutes, P = 0.04) and rapid eye movement sleep was longer than in CS (54 vs 0 minutes, P = 0.02). In the CS group, total sleep time during night-time was longer (8.7 vs 7.3 hours, P = 0.047) and frequency of arousal was lower (2.2 vs 4.4 event/hour, P = 0.03) than those in the DSI group. All mechanically ventilated patients demonstrated abnormal sleep architecture, but, compared with CS, DSI increased the amount of slow wave sleep and rapid eye movement sleep.
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Anaesth Intensive Care · May 2011
The relationship between blood lactate and survival following the use of adrenaline in the treatment of septic shock.
This prospective observational study evaluates the relationship between adrenaline, lactate and intensive care unit survival in septic shock. Forty patients requiring adrenaline therapy for a first episode of septic shock acquired > 24 hours after admission to the intensive care unit had blood lactate levels measured two-hourly over a 24-hour period. Adrenaline therapy was escalated until target mean arterial pressure was reached. ⋯ Peak lactate correlated with peak adrenaline (rho = 0.34, P = 0.032). Lactate index was the only independent predictor of survival after controlling for age and Acute Physiological and Chronic Health Evaluation II score (odds ratio 1.14, 95% confidence interval 1.03 to 1.26, P = 0.009). A high lactate following adrenaline administration may be a beneficial and appropriate response.