British journal of anaesthesia
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Randomized Controlled Trial Clinical Trial
Effect of adrenaline on extradural anaesthesia, plasma lignocaine concentrations and the feto-placental unit during elective caesarean section.
Extradural anaesthesia was induced with either 2% lignocaine or 2% lignocaine with adrenaline 1:200,000 in 20 patients undergoing elective Caesarean section. With the adrenaline-containing solution, a smaller dose of lignocaine was required to produce an adequate block and the lignocaine concentrations in both mother and neonate were significantly smaller compared with the plain solution. Arterial pressures were less in the adrenaline group, but there was no difference in umbilical flow velocity waveform, fetal heart rate or fetal outcome. Neither feto-placental circulation nor fetal outcome were affected adversely by episodes of hypotension or the ephedrine used for treatment.
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Randomized Controlled Trial Clinical Trial
Attenuation of the pressor response to tracheal intubation by magnesium sulphate with and without alfentanil in hypertensive proteinuric patients undergoing caesarean section.
The pressor response to tracheal intubation is known to be exaggerated in patients with gestational proteinuric hypertension (GPH). We have studied the effect of pretreatment with magnesium sulphate 40 mg kg-1 or 30 mg kg-1 with alfentanil 7.5 micrograms kg-1 on this pressor response in 38 patients with moderate to severe GPH. ⋯ There was no significant difference in fetal outcome between groups. Both pretreatment methods produced satisfactory control of catecholamine release.
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Randomized Controlled Trial Comparative Study Clinical Trial
Comparison of plain and alkalinized local anaesthetic mixtures of lignocaine and bupivacaine for elective extradural caesarean section.
We have examined a local anaesthetic mixture of 0.5% bupivacaine 10 ml and 2% lignocaine 10 ml with adrenaline 1 in 200,000, to which 8.4% sodium bicarbonate 2 ml was added, for extradural Caesarean section. The alkalinized mixture of local anaesthetics produced a block of more rapid onset and density than a mixture of bupivacaine and lignocaine alone (P less than 0.001).
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Randomized Controlled Trial Clinical Trial
Pressure support ventilation using a new tracheal gas injection tube.
In order to explore new types of jet ventilation, we tested a tracheal gas injection tube (TGIT) which included six thin capillaries and provided high pressure injection. The driving pressure was chosen to yield a plateau of inspiratory tracheal pressure of 10 cm H2O. An original controller was built to monitor spirometry and trigger injection in order to deliver both pressure controlled ventilation (PCVTGIT) and a new mode of inspiratory pressure support jet ventilation (IPSTGIT). ⋯ IPSTGIT, compared with spontaneous breathing increased minute ventilation (from 5.7 (SD 1.6) to 7.1 (1.7) litre min-1) (P less than 0.001). It reduced the total work of breathing (from 0.625 (0.223) to 0.263 (0.151) J litre-1, respectively) (P less than 0.01) and the occlusion pressure (from 2.62 (1.28) to 1.36 (0.74) cm H2O, respectively) (P less than 0.01). It is concluded that this TGIT used with a specific system for sensing and triggering ventilation allows inspiratory pressure support during low frequency jet ventilation.
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Randomized Controlled Trial Clinical Trial
Effect of i.v. low-dose adrenaline and phenylephrine infusions on plasma concentrations of bupivacaine after lumbar extradural anaesthesia in elderly patients.
Thirty patients undergoing primary total hip replacement under lumbar extradural anaesthesia with 0.75% bupivacaine 25 ml were allocated randomly to receive either low-dose adrenaline or phenylephrine infusions i.v. throughout surgery. Haemodynamic measurements and arterial blood samples were obtained before the extradural injection and at 10, 20, 30, 40, 50, 60 and 90 min thereafter. ⋯ Cardiac output was significantly greater in patients receiving adrenaline infusions (P less than 0.01). It is postulated that the smaller circulating concentrations of bupivacaine observed in patients receiving adrenaline were caused by increased cardiac output and a greater volume of distribution than in patients receiving phenylephrine.