British journal of anaesthesia
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Randomized Controlled Trial Clinical Trial
Influence of dose and timing of administration of morphine on postoperative pain and analgesic requirements.
In a randomized, double-blind study, we have investigated the effect of dose and timing of administration of morphine on postoperative pain and analgesic requirements in 60 patients undergoing hysterectomy, with or without salpingo-oophorectomy. Patients were allocated randomly to one of three groups: during standardized general anaesthesia, group post received morphine 0.15 mg kg-1 i.v. at peritoneal closure after hysterectomy; group pre-low received morphine 0.15 mg kg-1 on induction of anaesthesia; and group pre-high received morphine 0.3 mg kg-1 on induction of anaesthesia. ⋯ Pain scores (at rest and on movement) were similar in the three groups. A large dose of morphine 0.3 mg kg-1 i.v. on induction of anaesthesia significantly reduced postoperative PCA morphine requirements compared with the smaller dose (0.15 mg kg-1) administered at induction or peritoneal closure, in patients undergoing hysterectomy, with or without salpingo-oophorectomy.
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Randomized Controlled Trial Clinical Trial
Effect of isoflurane and sevoflurane on the magnitude and time course of neuromuscular block produced by vecuronium, pancuronium and atracurium.
We have compared the ability of equipotent concentrations of isoflurane and sevoflurane to enhance the effect of non-depolarizing neuromuscular blocking drugs. Ninety ASA I and II patients of both sexes, aged 18-50 yr, were stratified into three blocker groups (Vec, Pan and Atr), to undergo neuromuscular block with vecuronium (n = 30), pancuronium (n = 30) or atracurium (n = 30), respectively. Within each group, patients were allocated randomly to one of three anaesthetic subgroups to undergo maintenance of anaesthesia with: (1) alfentanil-nitrous oxide-oxygen (n = 10); (2) alfentanil-nitrous oxide-oxygen-isoflurane (n = 10); or (3) alfentanil-nitrous oxide-oxygen-sevoflurane (n = 10) anaesthesia. ⋯ In the Vec and Pan groups, a total dose of 40 micrograms kg-1 of vecuronium or pancuronium, respectively, was given, and in the Atr group a total dose of atracurium 100 micrograms kg-1. Each blocker was given in four equal doses and administered cumulatively. We showed that 0.95% isoflurane and 1.70% sevoflurane (corresponding to 0.8 MAC of each inhalation anaesthetic, omitting the MAC contribution of nitrous oxide) augmented and prolonged the neuromuscular block produced by vecuronium, pancuronium and atracurium to a similar degree.
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Clinical Trial Controlled Clinical Trial
Radial artery tonometry: moderately accurate but unpredictable technique of continuous non-invasive arterial pressure measurement.
Radial artery tonometry provides continuous measurement of non-invasive arterial pressure (CNAP) by a sensor positioned above the radial artery. An inflatable upper arm cuff enables intermittent oscillometric calibration. CNAP was compared with invasive radial artery pressure recordings from the opposite wrist in 22 high-risk surgical patients with an inter-arm oscillometric mean arterial pressure difference < or = 10 mm Hg. ⋯ Individual accuracy of oscillometry was good or acceptable in all 22 patients. The trend in CNAP changes (difference between consecutive measurements) was sufficiently accurate during induction of anaesthesia, as only 47 (7.6%), 14 (2.3%) and 27 (4.4%) of 616 systolic, diastolic and mean CNAP values differed by more than 10 mm Hg of invasive pressure trends. We conclude that: intermittent oscillometry provides accurate arterial pressure monitoring; CNAP measurements offer a reliable trend indicator of pressure changes during induction of anaesthesia and may be considered an alternative to invasive pressure measurements, should arterial cannulation be difficult in an awake patient; and accuracy of absolute CNAP values is only moderate and unpredictable, thus radial artery tonometry should not replace invasive monitoring in high-risk patients during major surgical procedures.
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Randomized Controlled Trial Clinical Trial
Delayed forced air warming prevents hypothermia during abdominal aortic surgery.
We have evaluated the efficacy of the delayed forced air warming during abdominal aortic surgery in 18 patients. Patients were allocated randomly to one of two groups: the control group (n = 9) received no intraoperative warming device; the Bair-Hugger group (n = 9) had active skin surface warming with an upper body cover. ⋯ In the control group, core temperature continued to decrease until the end of surgery, whereas in the Bair-Hugger group, the reduction in core temperature stopped after 1 h of warming, and then rewarming began. At the end of surgery, core temperature in the Bair-Hugger group was similar to core temperature before induction, and was higher than core temperature in the control group (P < 0.003).
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Case Reports
Reducing the potential morbidity of an unintentional spinal anaesthetic by aspirating cerebrospinal fluid.
We describe two cases where we attempted to reduce the adverse effects of inadvertent spinal anaesthesia by aspirating local anaesthetic-contaminated cerebrospinal fluid (CSF). Analysis of this CSF for its local anaesthetic concentration revealed that we were able to recover 51% and 39% of the administered lignocaine. It is suggested that such aspiration may be a helpful additional measure to the supportive management of this complication.