Lancet
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Randomized Controlled Trial Clinical Trial
Prevention of atelectasis during general anaesthesia.
Atelectasis is an important cause of impaired gas exchange during general anaesthesia; it causes pulmonary shunting. We studied the effects of gas composition on the formation of atelectasis and on gas exchange during the induction of general anaesthesia. In 12 adult patients, the lungs were ventilated with 30% oxygen in nitrogen during anaesthesia induction, and in another 12, a conventional technique was used (100% oxygen during induction and 40% oxygen in nitrogen thereafter). ⋯ In subgroup B, the shunt increased from 2.6 (5.2)% to 9.8 (5.7)% of cardiac output. These results suggest that the composition of inspired gas is important in atelectasis formation during general anaesthesia. Use of a lower oxygen concentration than is now standard practice might prevent the early formation of atelectasis.
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Randomized Controlled Trial Comparative Study Clinical Trial
Randomised comparison of combined spinal-epidural and standard epidural analgesia in labour.
Epidural analgesia has a well-established role in labour, but has the drawbacks of delayed onset and motor blockade. The combined spinal-epidural technique may overcome these drawbacks. We carried out a randomised observational study to assess maternal satisfaction with the standard and combined techniques among 197 women in labour. ⋯ In the standard epidural group 32 had leg weakness at 20 min (p = 0.001), and the proportion of mothers with weakness increased in this group during labour. There were no differences in side-effects, except for mild pruritus, which was more common in the combined spinal-epidural group (42 vs 1%; p < 0.0001). Overall, women seem to prefer the low-dose combined spinal-epidural technique to standard epidurals, perhaps because of the faster onset, less motor block, and feelings of greater self-control.