British journal of anaesthesia
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Randomized Controlled Trial Comparative Study Clinical Trial
Fast-track cardiac anaesthesia in the elderly: effect of two different anaesthetic techniques on mental recovery.
Elderly patients may be considered for 'fast-track' cardiac anaesthesia, but can suffer psychological complications and slow recovery of mental function after surgery, which can interfere with recovery. Reduced metabolism and changed distribution of anaesthetic and sedative agents can cause poor recovery. We made a prospective randomized comparison of mental function, haemodynamic stability and extubation and discharge times in elderly patients (65-79 yr) receiving two premedication, anaesthetic and sedative techniques. ⋯ Impairment of mental function was noted in 41% of patients in the propofol group and 83% in the lorazepam and midazolam group (P=0.001) 18 h after extubation. Patients in the propofol group were extubated earlier [1.4 (SD 0.6) vs 1.9 (0.8) h, P=0.02]; and reached standard intensive care unit discharge criteria [7.6 (4.6) vs 14.2 (13) h, P=0.02] and hospital discharge criteria [4.3 (1.0) vs 4.9 (1.1) days, P=0.04) sooner than patients in the lorazepam and midazolam group, but actual discharge times did not differ between the groups. Haemodynamic values were stable in both groups.
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Randomized Controlled Trial Clinical Trial
Dexamethasone is a cost-effective alternative to ondansetron in preventing PONV after paediatric strabismus repair.
This study evaluated the antiemetic efficacy, cost-effectiveness and clinical utility of prophylactic ondansetron and dexamethasone compared with placebo in the prevention of postoperative nausea and vomiting (PONV) in 135 children (2-15 yr, ASA I-II) undergoing strabismus repair. After induction with halothane and nitrous oxide in oxygen or i.v. thiopental, the children received i.v. dexamethasone 1 mg kg(-1) to a maximum of 25 mg, ondansetron 100 microg kg(-1) to a maximum of 4 mg or placebo (n=45). Episodes of PONV were recorded for the first 24 h after the operation. ⋯ The incidence (P=0.04) and severity (P=0.03) of PONV at the 6-24 h epoch were significantly less in the dexamethasone group than in the ondansetron group. Recovery time (P=0.07), fast tracking time (P=0.6), parental satisfaction scores (P=0.08) and NNTP PONV were comparable (NNTP=2) in both the ondansetron and the dexamethasone group. The cost to benefit a child with dexamethasone was approximately 22 times less than that of ondansetron.
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Randomized Controlled Trial Clinical Trial
Waste gas exposure to sevoflurane and nitrous oxide during anaesthesia using the oesophageal-tracheal Combitube small adult.
Exposure to sevoflurane (SEV) and nitrous oxide during ventilation using a Combitube (37Fr) small adult (SA) was compared with waste gas exposure using conventional endotracheal tubes. Trace concentrations of SEV and nitrous oxide were assessed using a direct reading spectrometer during 40 gynaecological laparoscopic procedures under general anaesthesia. ⋯ These values caused comparable contamination of the anaesthetists' breathing zone (SEV 0.6 (0.2) p.p.m. and nitrous oxide 4.3 (3.7) p.p.m. for the Combitube SA group, compared with SEV 0.5 (0.2) p.p.m. and nitrous oxide 4.1 (1.8) p.p.m. for the endotracheal tube group). We conclude that the use of the Combitube SA during positive pressure ventilation is not necessarily associated with increased waste gas exposure, especially when air conditioning and scavenging devices are available.
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Randomized Controlled Trial Clinical Trial
Intrathecal midazolam increases the analgesic effects of spinal blockade with bupivacaine in patients undergoing haemorrhoidectomy.
In the present double-blind study we aimed to evaluate the postoperative analgesic effects of intrathecal midazolam with bupivacaine following haemorrhoidectomy. Forty-five patients were randomly allocated to one of three groups: the control group received 1 ml of 0.5% heavy bupivacaine plus 0.2 ml of 0.9% saline intrathecally, group BM1 received 1 ml of 0.5% bupivacaine plus 0.2 ml of 0.5% preservative-free midazolam and group BM2 received 1 ml of 0.5% bupivacaine plus 0.4 ml of 0.5% midazolam. Time to first analgesia was significantly greater in the midazolam groups than in the placebo and significantly less in the BM1 group than in the BM2 group.
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Recent research has shown that high-frequency, gamma-band electroencephalographic (EEG) oscillations (40-60 Hz) may be an important marker of the conscious state. We compared the ability of the bispectral index (BIS) to distinguish the awake and anaesthetized states during the induction of general anaesthesia with: (i) components of the BIS (BetaRatio, SynchFastSlow); (ii) a new EEG variable--the median frequency of the first time derivative of the EEG signal (SE50d); and (iii) the SE50d derived from an EEG signal that has had the frequencies above 30 Hz removed (SE50d(30Hz)). Two groups of subjects were studied: (i) nine volunteers undergoing a short propofol infusion until loss of response to verbal command, and (ii) 84 patients undergoing routine anaesthesia for a variety of surgical procedures. ⋯ In the patient group, the BIS components were equivalent to the BIS in separating the awake from the surgically anaesthetized states (area under receiver operating curve: BIS 0.95, SE50d 0.95, BetaRatio 0.96). Using the submental electromyogram (EMG) signal to estimate the frontalis EMG (30-47 Hz) signal, the changes in EMG signal were, on average, about one-tenth the magnitude of the EEG. We conclude that: (i) there exist simpler derived EEG variables that are similar in accuracy to the BIS; (ii) it is important to avoid filtering out the EEG frequencies above 30 Hz; and (iii) in most patients the confounding effects of the frontalis EMG on the EEG are minimal.