Ultrasound-Guided Occipital Nerve Blocks as Part of Multi-Modal Perioperative Analgesia in Pediatric Posterior Craniotomies: A Case Series.

Various regional anesthetics have been used for postoperative analgesia for pediatric craniotomy. In this case series, we report retrospectively collected data on postoperative pain and analgesic use in 44 patients who received ultrasound-guided occipital nerve blocks in addition to intravenous analgesic agents for posterior craniotomy procedures. In the immediate post-anesthesia care unit, pain was rated as zero or well controlled in 77% of patients, with only 43% requiring intravenous or demand patient-controlled analgesia opioids. There were no block-related complications. Occipital nerve blocks may constitute a safe and effective component of multimodal analgesia in this population.

Interventional Procedures for Chronic Pain in Children and Adolescents: A Review of the Current Evidence.

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.

The Effect of Systemic Magnesium on Postsurgical Pain in Children Undergoing Tonsillectomies: A Double-Blinded, Randomized, Placebo-Controlled Trial.

BACKGROUND: 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 their effects in pediatric surgical patients remain 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 randomly assigned using a computer-generated table of random numbers to 1 of the 2 intervention groups: systemic magnesium infusion (initial loading dose 30 mg/kg given over 15 minutes followed by a continuous magnesium infusion 10 mg/kg/h) and the same volume of saline. The primary outcome was pain scores in the postanesthesia care unit (PACU) measured by FLACC (Face, Legs, Activity, Cry, Consolability) 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 randomly assigned and 60 completed the study. The area under pain scores (up to 90 minutes) was not different between the study groups, median (interquartile range [IQR]) of 30 (0-120) score × min and 45 (0-135) 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 (0-4.44) mg IV morphine, compared with the control, median (IQR) of 2.5 (0-4.99) mg IV morphine (P = 0.25). The serum level of magnesium was significantly lower in the control group than in the treatment group at the end of the surgery (P < 0.001). CONCLUSIONS: 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.

A randomized comparison of the laryngeal mask airway supreme™ and laryngeal mask airway unique™ in infants and children: does cuff pressure influence leak pressure?

BACKGROUND: The cuff pressure for optimal airway sealing with first-generation laryngeal mask airway has been shown to be 40 cm H(2)O in children. Currently, there are no data regarding the ideal intracuff pressure for the laryngeal mask airway Supreme (Supreme) in children. OBJECTIVES: To compare the clinical performance of the laryngeal mask airway supreme with the laryngeal mask airway unique in infants and children. MATERIALS AND METHODS: One hundred eighty children were assigned to receive either a Supreme or a laryngeal mask airway-U. We hypothesized higher airway leak pressure with the Supreme at both 40 cm H(2)O and 60 cm H(2)O, when compared with the laryngeal mask airway-U. Ease and time of insertion, insertion attempts, fiber optic examination, quality of airway, efficacy of mechanical ventilation, success of gastric tube placement (Supreme), incidence of gastric insufflation, and complications were also assessed. RESULTS: Airway leak pressure at an intracuff pressure of 60 cm H(2)O for the Supreme was 17.4 (5.2) vs laryngeal mask airway-U at 18.4 (6.6) cm H(2)O and did not differ when compared to an intracuff pressure of 40 cm H(2)O for both devices; Supreme at 17.2 (5) vs laryngeal mask airway-U at 17.7 (6) cm H(2)O. The laryngeal mask airway-U was associated with higher first-attempt success rates. The Supreme was associated with less gastric insufflation than the laryngeal mask airway-U. CONCLUSIONS: 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.

A randomized equivalence trial comparing the i-gel and laryngeal mask airway Supreme in children.

BACKGROUND: The laryngeal mask airway Supreme (Supreme) is a new single-use supraglottic device with gastric access capability now available in all sizes for children. OBJECTIVES: To compare the i-gel with the Supreme in children for routine airway maintenance. MATERIALS/METHODS: One hundred and seventy children, aged 3 months to 11 years, 5-50 kg in weight, were randomly assigned to receive either the i-gel or the Supreme. The primary outcome measured was airway leak pressure. Secondary outcomes included the following: ease and time for insertion, insertion success rate, fiberoptic grade of view, ease of gastric tube placement, number of airway manipulations, quality of airway during anesthetic maintenance, and complications. RESULTS: A total of 168 patients were assessed for the outcomes. The median (IQR [range]) airway leak pressure for the i-gel was higher than with the Supreme, 20 (18-25 [9-40]) cm H(2)O vs 17 (14-22 [10-40]) cm H(2)O, respectively (P = 0.001). There were no differences in the time for device insertion, fiberoptic grade of view, quality of airway, and complications. Median (IQR[range]) time of successful insertion of a gastric tube was faster with the Supreme, 12 (9.2-14.3 [5.2-44.2]) s than with the i-gel, 14 (11.9-19 [6.9-75]) s; P = 0.01. The number of airway manipulations during placement was higher with the i-gel than with the laryngeal mask airway Supreme (12 vs 13 patients), P = 0.02. CONCLUSIONS: 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.

A randomized trial comparing the Ambu ® Aura-i ™ with the air-Q ™ intubating laryngeal airway as conduits for tracheal intubation in children.

OBJECTIVES: To assess the clinical performance of the Ambu Aura-i (Aura-i) in children. AIM: To compare the Aura-i with the air-Q intubating laryngeal airway (air-Q) for the purposes of fiberoptic-guided tracheal intubation. BACKGROUND: The Aura-i is a new supraglottic airway designed for tracheal intubation. MATERIALS/METHODS: One hundred twenty children, ages 1 month to 6 years, were randomized to receive either the Aura-i or air-Q, and divided into three equal subgroups (Group 1, 2, 3) based on weight. The time for successful tracheal intubation was primarily assessed. The ease, time, and number of attempts for successful device insertion, leak pressures, fiberoptic grade of laryngeal view, number of attempts time for removal of the device after tracheal intubation, and complications were secondarily assessed. RESULTS: Device placement, tracheal intubation, and removal after tracheal intubation were successful in all patients. There were no differences in the time to successful tracheal intubation through the Aura-i (32.9 ± 13.3 s), and the air-Q (33.9 ± 13 s; P = 0.68), or fiberoptic grade of view between devices. There was not a statistically significant correlation between the time to intubation and the fiberoptic grade of laryngeal view in any of the groups. There were no statistically significant differences in the overall leak pressures, air-Q (18.3 ± 6.1 cm H(2) O) vs Aura-i (16 ± 5.1 cm H(2) O; P = 0.05). In Group 1 (5-10 kg), leak pressures were higher with the air-Q (23.4 ± 7.2 cm H(2) O) than the Aura-i (16.1 ± 5.2 cm H(2) O; P = 0.001). There were no statistically significant differences in the time for removal between the two devices (P = 0.11). However, with the size 1.5 Aura-i, the pilot balloon of the tracheal tube was removed in order to facilitate the removal of the device after tracheal intubation. CONCLUSIONS: 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.

Charge at the lidocaine binding site residue Phe-1759 affects permeation in human cardiac voltage-gated sodium channels.

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 (gamma) was reduced from WT in both F1759K (by 38%) and F1759R (by 18%). The negatively charged mutant F1759E increased gamma 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.