Anesthesiology
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More than 500,000 elective tonsillectomies are performed in US children annually. Pain after pediatric tonsillectomy is common, often severe, and undertreated. There is no consensus on the optimal management of perioperative tonsillectomy pain. Methadone, with an elimination half-life of 1-2 days, has a longer duration of effect than short-duration opioids such as fentanyl. The primary objective of this study was to investigate the intraoperative use of methadone for pediatric tonsillectomy. It tested the hypothesis that methadone would result in less postoperative opioid use compared with short-duration opioids in children post-tonsillectomy. ⋯ This small initial study in children undergoing tonsillectomy found that single-dose intraoperative methadone at 0.15 mg/kg age ideal body weight was opioid-sparing compared with intermittent fentanyl.
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Aeration heterogeneity affects lung stress and influences outcomes in adults with acute respiratory distress syndrome (ARDS). We hypothesize that aeration heterogeneity may differ between neonatal respiratory disorders and is associated with oxygenation, so its evaluation may be relevant in managing respiratory support. ⋯ Global aeration heterogeneity and regional aeration heterogeneity differ amongst neonatal respiratory disorders. TTN and evolving BPD have the highest intra-patient aeration heterogeneity. TTN, evolving BPD and NARDS have the highest inter-patient aeration heterogeneity, but the latter two have the most diffuse injury and worst gas exchange. Higher aeration heterogeneity is associated with better total lung aeration and oxygenation.
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Volatile anesthetics induce hyperpolarizing potassium currents in spinal cord neurons that may contribute to their mechanism of action. They are induced at lower concentrations of isoflurane in noncholinergic neurons from mice carrying a loss-of-function mutation of the Ndufs4 gene, required for mitochondrial complex I function. The yeast NADH dehydrogenase enzyme, NDi1, can restore mitochondrial function in the absence of normal complex I activity, and gain-of-function Ndi1 transgenic mice are resistant to volatile anesthetics. The authors tested whether NDi1 would reduce the hyperpolarization caused by isoflurane in neurons from Ndufs4 and wild-type mice. Since volatile anesthetic behavioral hypersensitivity in Ndufs4 is transduced uniquely by glutamatergic neurons, it was also tested whether these currents were also unique to glutamatergic neurons in the Ndufs4 spinal cord. ⋯ Bypassing complex I by overexpression of NDi1 eliminates increases in potassium currents induced by isoflurane in the spinal cord. The isoflurane-induced potassium currents in glutamatergic neurons represent a potential downstream mechanism of complex I inhibition in determining minimum alveolar concentration.