British journal of anaesthesia
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Clinical Trial Controlled Clinical Trial
Cytokine balance and immunosuppressive changes at cardiac surgery: contrasting response between patients and isolated CPB circuits.
In vitro work suggests that IL-10 plays a pivotal role in controlling the balance of pro- and anti-inflammatory cytokines and monocyte HLA-DR expression. In 20 patients undergoing cardiac surgery, we investigated elaboration of interleukin 10 (IL-10) and its relationship to pro- and anti-inflammatory cytokines and leucocyte expression of HLA-DR and adhesion molecules. There were small increases in pro-inflammatory cytokines (IL-1, IL-8 and tumour necrosis factor (TNF) after induction, returning to baseline on induction of cardiopulmonary bypass (CPB). ⋯ The reduction in lymphocyte HLA-DR expression, observed throughout the study period (P < 0.01), was greater with fentanyl (P < 0.05). Monocyte HLA-DR expression increased (P < 0.05), but to a lesser extent with fentanyl (P > 0.05). In contrast with the in vivo response where there was a phased anti-inflammatory response beginning with IL-10, in the isolated CPB model no anti-inflammatory cytokine response occurred.
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Case Reports
Emergency use of the laryngeal mask airway in severe upper airway obstruction caused by supraglottic oedema.
We report two cases of severe upper airway obstruction caused by supraglottic oedema which developed rapidly at the time of anaesthesia. Conventional methods to relieve the obstruction failed and it was only overcome when a laryngeal mask airway (LMA) was inserted and positive pressure applied manually during inspiration. In one case a fibrescope was passed via the LMA and this revealed two cushions of oedematous false vocal cords protruding into the bowel of the LMA which were pushed out of the way when positive pressure was applied during inspiration. We believe that the LMA should be considered in the emergency management of severe upper airway obstruction even when this involves supraglottic oedema.
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Comparative Study Clinical Trial Controlled Clinical Trial
Comparison between oxygen consumption calculated by Fick's principle using a continuous thermodilution technique and measured by indirect calorimetry.
We calculated oxygen consumption by the reverse Fick principle (cVO2) using cardiac output measured with a new technique of continuous thermal dilution and compared these values with measurements made at the same time using a gas exchange method (mVO2). We studied nine patients in a stable condition after cardiac surgery. ⋯ The relative error of each method was 5% and 4% (continuous cardiac output and gas exchange methods, respectively). Calculation of VO2 using the new cardiac output technology had good repeatability compared with direct measurement, probably because of the high precision of measurement of cardiac output.
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Randomized Controlled Trial Comparative Study Clinical Trial Controlled Clinical Trial
Comparison of the effects of sub-hypnotic concentrations of propofol and halothane on the acute ventilatory response to hypoxia.
To compare the effects of sub-anaesthetic concentrations of propofol and halothane on the respiratory control system, we have studied the acute ventilatory response to isocapnic hypoxia (AHVR) in 12 adults with and without three different concentrations of propofol and halothane. Target doses for propofol were 0, 0.05, 0.1 and 0.2 of the effective plasma concentration (EC50 = 8.1 micrograms ml-1). Target doses for halothane were 0, 0.05, 0.1 and 0.2 minimum alveolar concentration (MAC = 0.77%). ⋯ The decline in AHVR with increasing dose for both drugs was statistically significant (ANOVA, P < 0.001); there was no significant difference between the two drugs with respect to this decline. Normoxic ventilation with propofol declined from 13.2 (1.6) litre min-1 (0.01 EC50) to 8.3 (0.9 litre min-1 (0.26 EC50), and with halothane declined from 13.5 (2.0) litre min-1 (0 MAC) to 11.8 (1.6) litre min-1 (0.2 MAC). This was significant for both drugs (ANOVA, P < 0.001).
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Randomized Controlled Trial Comparative Study Clinical Trial
Comparison of the effects of adrenaline, clonidine and ketamine on the duration of caudal analgesia produced by bupivacaine in children.
Sixty boys, aged 1-10 yr, undergoing orchidopexy were allocated randomly to receive one of three solutions for caudal extradural injection. Group A received 0.25% bupivacaine 1 ml kg-1 with adrenaline 5 micrograms ml-1 (1/200,000), group C received 0.25% bupivacaine 1 ml kg-1 with clonidine 2 micrograms kg-1 and group K received 0.25% bupivacaine 1 ml kg-1 with ketamine 0.5 mg kg-1. ⋯ The median duration of caudal analgesia was 12.5 h in group K compared with 5.8 h in group C (P < 0.05) and 3.2 h in group A (P < 0.01). There were no differences between the groups in the incidence of motor block, urinary retention or postoperative sedation.