Anaesthesia
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Randomized Controlled Trial
The effect of magnesium sulphate infusion on the incidence and severity of emergence agitation in children undergoing adenotonsillectomy using sevoflurane anaesthesia.
This randomised, controlled, double-blind study investigated the effects of intra-operative magnesium sulphate administration on the incidence of emergence agitation in children undergoing adenotonsillectomy using sevoflurane anaesthesia. Seventy children were randomly allocated to receive a 30 mg.kg(-1) bolus of intravenous magnesium sulphate after induction of anaesthesia followed by a continuous infusion of 10 mg.kg(-1).h(-1) or an equal volume of saline 0.9%. All children received titrated sevoflurane anaesthesia adjusted to maintain haemodynamic stability. ⋯ Emergence agitation was more common in the control group than in the magnesium group (23 (72%) and 12 (36%), respectively (p = 0.004)), with a relative risk of 0.51 (95% CI 0.31-0.84), an absolute risk reduction of 0.35 (95% CI 0.10-0.54), and number needed to treat of 3 (95% CI 2-9). Postoperative pain scores were comparable in the two groups. Magnesium sulphate reduces the incidence and severity of emergence agitation in children undergoing adenotonsillectomy using sevoflurane anaesthesia and is not associated with increased postoperative side-effects or delayed recovery.
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Randomized Controlled Trial Comparative Study
Comparison of the Baska(®) mask with the single-use laryngeal mask airway in low-risk female patients undergoing ambulatory surgery.
We compared the Baska(®) mask with the single-use classic laryngeal mask airway (cLMA) in 150 females at low risk for difficult tracheal intubation in a randomised, controlled clinical trial. We found that median (IQR [range]) seal pressure was significantly higher with the Baska mask compared with the cLMA (40 (34-40 [16-40]) vs 22 (18-25 [14-40]) cmH2O, respectively, p < 0.001), indicating a better seal. In contrast, the first time success rate for insertion of the Baska mask was lower than that seen with the cLMA (52/71 (73%) vs 77/99 (98%), respectively, p < 0.001). ⋯ The Baska mask proved more difficult to insert, requiring more insertion attempts, taking longer to insert and had higher median (IQR [range]) insertion difficulty scores (1.6 (0.8-2.2 [0.1-5.6]) vs 0.5 (0.3-1.4 [0.1-4.0]), respectively, p < 0.001). There was also an increased rate of minor blood staining of the Baska mask after removal, but there were no differences in other complication rates, such as laryngospasm, or in the severity of throat discomfort. In conclusion, in clinical situations where the seal with the glottic aperture takes priority over ease of insertion, the Baska mask may provide a useful alternative to the cLMA.
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The aim of this study was to predict the optimal depth for insertion of a left-sided central venous catheter in children. Using 3D chest computed tomography angiography, we measured the distance from a point where the internal jugular vein is at the superior border of the clavicle, and from a point where the subclavian vein is inferior to the anterior border of the clavicle, to the junction of the superior vena cava and the right atrium in 257 children. ⋯ Simple formulae for the depth of a central venous catheter via the left internal jugular vein (0.07 × height (cm)) and the left subclavian vein (0.08 × height (cm)) were developed to predict placement of the central venous catheter tip at the junction of the superior vena cava with the right atrium. Using these fomulae, the proportion of catheter tips predicted to be correctly located was 98.5% (95% CI 96.8-100%) and 94.0% (95% CI 90.8-97.3%), respectively.
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Comparative Study
The ability of bispectral index to detect intra-operative wakefulness during isoflurane/air anaesthesia, compared with the isolated forearm technique.
Clinical signs are unreliable for guiding anaesthetic administration and it is suggested that using the bispectral index can improve anaesthetic delivery. In the current study, isoflurane administration was guided to a bispectral index range of 55-60. Intra-operative responsiveness, as assessed by the isolated forearm technique, was compared with whether the bispectral index predicted/identified a patient's appropriate hand movements in response to commands. ⋯ For patients who responded more than once during surgery, the bispectral index value associated with a response was not constant. No patient had recall for surgery or the taped commands, and only one could remember dreaming (a good dream). Titrating isoflurane to target a bispectral index range of 55-60 may result in an unacceptable number of patients who are conscious during surgery (albeit without recall).