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Objective: Extracorporeal membrane oxygenation (ECMO) is increasingly employed in the management of patients with severe cardiac and pulmonary dysfunction. Patients commonly require tracheostomy for ventilator liberation. Though bedside percutaneous tracheostomy is commonly performed, it has the potential for increased complications, both surgical and with the ECMO circuit. We examined surgical outcomes of bedside percutaneous tracheostomy in the ECMO population. Methods: Patients were identified from an institutional database for bedside procedures. Demographics and data on complications were recorded. Descriptive statistics were calculated. Results: 37 patients on ECMO at the time of tracheostomy were identified. Median age and BMI were 43.2 and 28.0, respectively. 33 patients (89%) were on VV ECMO, and 4 (11%) were on VA ECMO. All were on anticoagulation prior to tracheostomy, which was held for 4 h before and after the procedure in all cases. There were no procedure-related deaths or airway losses. No patients experienced periprocedural clotting events of their ECMO circuit or oxygenator within 24 h. 3 patients (8%) required reintervention (re-exploration or bronchoscopy) for bleeding. Four other patients (10%) had minor bleeding controlled with packing. One patient had pneumomediastinum which resolved without intervention, and one had an occlusion of their tracheostomy which was treated with tracheostomy exchange. Conclusions: Bedside percutaneous tracheostomy is feasible for patients on ECMO. Further study is needed to determine specific risk factors for complications and means to mitigate these. Bedside percutaneous tracheostomy may be considered as part of the management of patients on ECMO to help facilitate liberation from mechanical support.

BackgroundHirano bodies are actin-rich paracrystalline inclusions found in brains of patients with Alzheimer’s disease (AD), frontotemporal dementia (FTD), and in normal aged individuals. Although studies of post-mortem brain tissue provide clues of etiology, the physiological function of Hirano bodies remains unknown. A cell culture model was utilized to study the interactions of mutant tau proteins, model Hirano bodies, and GSK3β in human astrocytoma cells.ResultsMost tau variants showed co-localization with model Hirano bodies. Cosedimentation assays revealed this interaction may be direct, as recombinant purified forms of tau are all capable of binding F-actin. Model Hirano bodies had no effect or enhanced cell death induced by tau in the absence of amyloid precursor protein intracellular domain (AICD). In the presence of AICD and tau, synergistic cell death was observed in most cases, and model Hirano bodies decreased this synergistic cell death, except for forms of tau that caused significant cell death in the presence of Hirano bodies only. A role for the kinase GSK3β is suggested by the finding that a dominant negative form of GSK3β reduces this synergistic cell death. A subset of Hirano bodies in brain tissue of both Alzheimer’s disease and normal aged individuals was found to contain tau, with some Hirano bodies in Alzheimer’s disease brains containing hyperphosphorylated tau.ConclusionThe results demonstrate a complex interaction between tau and AICD involving activation of GSK3β in promoting cell death, and the ability of Hirano bodies to modulate this process.

Minimum and maximum MEA doses exist, between which increasing opioid dose is associated with decreased ability to achieve clinically meaningful improvement following spine surgery. Patients with preoperative MEA dose exceeding 29 mg/d, the lower limit of the 95% credible interval for the mean MEA dose above which patients exhibit significantly decreased achievement of MCID, may be considered for preoperative opioid weaning.