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 Comparative Study Clinical Trial
Use of a 25-gauge Whitacre needle to reduce the incidence of postdural puncture headache.
We studied 200 orthopaedic inpatients (111 males) aged 15-84 yr who received spinal anaesthesia with one of two types of Whitacre spinal needle: 22-gauge or 25-gauge. The incidence of headache, backache, failure of spinal anaesthesia and patient acceptability was investigated using a questionnaire. The incidence of postdural puncture headache (PDPH) was 4% in the 22-gauge group and 2% in the 25-gauge group. ⋯ Spinal anaesthesia was carried out successfully in all patients in both groups. Patient acceptance was high (98%) and there were no serious complications observed. We conclude that spinal anaesthesia is easy to perform with a 25-gauge pencil-point needle and is associated with a low incidence of PDPH.
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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.
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The presence of an intracranial neoplasm (ICN) during pregnancy has serious implications for the anaesthetic management of labour and delivery. The physiological changes of pregnancy and labour are potentially hazardous to women with ICN, but the provision of adequate pain relief during labour reduces the risk to the mother. Extradural anaesthesia is the only technique that provides pain-free labour reliably, but it carries added risks. ⋯ None suffered any complication related to the anaesthetic technique. At present, there are no published data on the influence of anaesthetic management on outcome of labour and delivery in patients with ICN. Anaesthetists should report such cases so that the relative risks of different management strategies may be assessed.