Both devices served as effective conduits for fiberoptic-guided tracheal intubation. The limitation of the narrower proximal airway tube of the size 1.5 Aura-i should be considered if cuffed tracheal tubes are to be utilized.

Our homology molecular model of the open/inactivated state of the Na + channel pore predicts, based on extensive mutagenesis data, that the local anaesthetic lidocaine docks eccentrically below the selectivity filter, such that physical occlusion is incomplete. Electrostatic field calculations suggest that the drug's positively charged amine produces an electrostatic barrier to permeation. To test the effect of charge at this pore level on permeation in hNa V 1.5 we replaced Phe-1759 of domain IVS6, the putative binding site for lidocaine's alkylamino end, with positively and negatively charged residues as well as the neutral cysteine and alanine. These mutations eliminated use-dependent lidocaine block with no effect on tonic/rested state block. Mutant whole cell currents were kinetically similar to wild type (WT). Single channel conductance (γ) was reduced from WT in both F1759K (by 38%) and F1759R (by 18%). The negatively charged mutant F1759E increased γ by 14%, as expected if the charge effect were electrostatic, although F1759D was like WT. None of the charged mutations affected Na + /K + selectivity. Calculation of difference electrostatic fields in the pore model predicted that lidocaine produced the largest positive electrostatic barrier, followed by lysine and arginine, respectively. Negatively charged glutamate and aspartate both lowered the barrier, with glutamate being more effective. Experimental data were in rank order agreement with the predicted changes in the energy profile. These results demonstrate that permeation rate is sensitive to the inner pore electrostatic field, and they are consistent with creation of an electrostatic barrier to ion permeation by lidocaine's charge. Local anaesthetic (LA) drugs such as lidocaine interfere with impulse conduction in nerve and muscle by binding to the inner pore of voltage-gated Na + channels and blocking current (Hille, 2001). The major drug mechanism of action is not resolved, with experimental evidence variously favouring steric block, stabilization of a closed state, or some combination of the two. Extensive site-directed mutagenesis experiments have provided strong evidence that lidocaine-like drugs (LA) bind in the inner pore. S6 segment residues in domains I, III and IV (but not II) have been shown to be important for use-dependent LA block (Ragsdale et al. 1994;Wright et al. 1998;Yarov-Yarovoy et al. 2001;Yarov-Yarovoy et al. 2002). Two residues in domain IV S6 are of particular importance -Phe-1759 (following the heart Na V 1.5 isoform numbering, corresponding to Phe-1579 in skeletal Na V 1.4 and Phe-1764 in brain Na V 1.2) and Tyr-1766 (Tyr-1586 in Na V 1.4; Tyr-1771 in Na V 1.2), because their alanine mutants exhibit the greatest changes in LA affinity. Open/inactivated state block of the brain isoform Na V 1.2 by etidocaine was reduced by 130-and 35-fold for the alanine substitutions of the phenylalanine and tyrosine, respectively (Ragsdale et al. 1994). Cysteine accessibility experiments with methanethiosulphonate (MTS) reagents confirm th...

In infants and children, when a single-use supraglottic device with gastric access capabilities is required, the i-gel demonstrated higher airway leak pressures and can be a useful alternative to the Supreme.

SummaryWe conducted a randomised trial comparing the self-pressurised air-Q TM intubating laryngeal airway (air-Q SP) with the LMA-Unique in 60 children undergoing surgery. Outcomes measured were airway leak pressure, ease and time for insertion, fibreoptic examination, incidence of gastric insufflation and complications. Median (

Advances in the field of paediatric regional anaesthesia have specific applications to both acute and chronic pain management. This review summarizes data regarding the safety of paediatric regional anaesthetic techniques. Current guidelines are provided for performing paediatric regional techniques, with a focus on applications for postoperative pain management. Brief descriptions of relevant anatomy followed by indications for commonly performed blocks are highlighted along with the potential of adverse side-effects.

Introduction Tonsillectomy is a frequently performed surgical procedure in children; however few multimodal analgesic strategies have been shown to improve postsurgical pain in this patient population. Systemic magnesium infusions have been shown to reliably improve postoperative pain in adults, but its effects in pediatric surgical patients remains to be determined. In the current investigation our main objective was to evaluate the use of systemic magnesium to improve postoperative pain in pediatric patients undergoing tonsillectomy. We hypothesized that children who received systemic magnesium infusions would have less post-tonsillectomy pain than the children who received saline infusions. Methods The study was a prospective, randomized, double-blinded, clinical trial. Subjects were randomized using a computer-generated table of random numbers to one of the two intervention groups: systemic magnesium infusion (initial loading dose 30 mg/kg given over 15 minutes followed by a continuous magnesium infusion 10 mg/kg/hr) or the same volume of saline. The primary outcome was pain scores in the postanesthesia care unit (PACU) measured by FLACC pain scores. Pain reduction was measured by the decrement in the area under the pain scale versus 90-minute postoperative time curve using the trapezoidal method. Secondary outcomes included opioid consumption in the PACU, emergence delirium scores (measured by the pediatric anesthesia emergence delirium scale) and parent satisfaction. Results Sixty subjects were randomized and 60 completed the study. The area under pain scores (up to 90 minutes) was not different between the study groups, median (IQR) of 30 (0 to 120) score*min and 45 (0 to 135) score*min for the magnesium and control groups, respectively, P= 0.74. Similarly, there was no clinically significant difference in the morphine consumption in the PACU between the magnesium group, median (IQR) of 2.0 (0 to 4.44) mg IV morphine compared to control, median (IQR) of 2.5 (0 to 4.99) mg IV morphine, P= 0.25. The serum level of magnesium was significantly lower in the control group compared to the treatment group at the end of the surgery (P<0.001). Discussion Despite a large number of studies demonstrating the efficacy of systemic magnesium for preventing postsurgical pain in adults, we could not find evidence for a significant clinical benefit of systemic magnesium infusion in children undergoing tonsillectomies. Our findings reiterate the importance of validating multimodal analgesic strategies in children that have been demonstrated to be effective in the adult population.

Intracuff pressures of 40 cm H(2)O may be sufficient for the Supreme in children, and there may be no added benefit of an intracuff pressure of 60 cm H(2)O, as leak pressures were similar. The Supreme may be preferred over the laryngeal mask airway-U for its lower rates of gastric insufflation and provision for gastric access when mechanical ventilation is utilized.

This review discusses the role of interventional procedures in the treatment of chronic pain in children and adolescents. Due to lack of scientific evidence, significant controversy surrounds the utility of invasive techniques for managing pediatric chronic pain states. Interventional procedures are a widely accepted modality for pain management in adults. The use of such techniques in children is supported only by case reports, case series, and very few randomized controlled studies. In addition, the potential for severe complications leaves open a debate on the safety of these invasive procedures, which must be confirmed by more extensive and accurate prospective studies.