Post-intubation tracheal rupture: poor healing of the tracheal wall

Purpose

To describe tracheal rupture after orotracheal intubation assisted by a tracheal tube introducer.

Clinical features

A 73-yr-old morbidly obese female patient with a history of hypertension underwent a total knee replacement. There were no anticipated signs of difficult intubation. Orotracheal intubation was attempted twice by direct laryngoscopy, and a Boussignac bougie was used as a tube exchanger for the second attempt. Seven hours after tracheal extubation, the patient became dyspneic and showed a large subcutaneous emphysema. A chest x-ray and computerized tomography scan revealed rupture of the posterior tracheal wall. The distal part of the injury was 26.5 cm from the patient’s teeth and 0.5 cm from the carina (i.e., beyond the normal location of the tracheal tube tip) and extended to the origin of the right main bronchus, where the tip of the Boussignac bougie was probably pushed. Formation of an endotracheal sac occurred during the first two weeks after intubation, accompanied by dyspnea and alveolar hypoventilation, but symptoms resolved favourably with conservative management.

Conclusion

The tracheal rupture was attributed to airway manipulations, and the distal location of the lesion suggests that the cause was the Boussignac bougie rather than the tracheal tube. Long-term healing of the injury was satisfactory, although the patient continued to complain of dyspnea one year after the rupture.     

Influence of caffeine on heart rate variability in patients with long-standing type 1 diabetes

OBJECTIVE: The effect of caffeine on cardiovascular health remains controversial. Patients with long-standing type 1 diabetes are at risk of autonomic failure and sudden cardiac death. We investigated the effects of caffeine on autonomic dysfunction (as assessed by heart rate variability [HRV]) in this high-risk group and in a control population. RESEARCH DESIGN AND METHODS: Using a randomized blinded, placebo-controlled, crossover design trial, we examined 2 weeks of caffeine consumption (250 mg twice daily) on HRV in 20 type 1 diabetic patients and 10 matched healthy volunteers. RESULTS: Baseline HRV was blunted in the diabetic patients (P < 0.0005 vs. control subjects) and markedly increased by caffeine in both groups (+103% in the group with diabetes [P = 0.009] and +38% in control subjects [P = 0.002]). The caffeine-associated increase in HRV was not statistically different between the control and the type 1 diabetes groups (P = 0.16). CONCLUSIONS: Modest amounts of caffeine improved autonomic function in diabetic patients and healthy volunteers. For individuals with abnormal HRV, regular caffeine use may have the potential to reduce the risk of cardiovascular events.     

Dynamics and Patterning of 5-Hydroxytryptamine 2 Subtype Receptors in JC Polyomavirus Entry

The organization and dynamics of plasma membrane receptors are a critical link in virus-receptor interactions, which finetune signaling efficiency and determine cellular responses during infection. Characterizing the mechanisms responsible for the active rearrangement and clustering of receptors may aid in developing novel strategies for the therapeutic treatment of viruses. Virus-receptor interactions are poorly understood at the nanoscale, yet they present an attractive target for the design of drugs and for the illumination of viral infection and pathogenesis. This study utilizes super-resolution microscopy and related techniques, which surpass traditional microscopy resolution limitations, to provide both a spatial and temporal assessment of the interactions of human JC polyomavirus (JCPyV) with 5-hydroxytrypamine 2 receptors (5-HT₂Rs) subtypes during viral entry. JCPyV causes asymptomatic kidney infection in the majority of the population and can cause fatal brain disease, and progressive multifocal leukoencephalopathy (PML), in immunocompromised individuals. Using Fluorescence Photoactivation Localization Microscopy (FPALM), the colocalization of JCPyV with 5-HT₂ receptor subtypes (5-HT_2A, 5-HT_2B, and 5-HT_2C) during viral attachment and viral entry was analyzed. JCPyV was found to significantly enhance the clustering of 5-HT₂ receptors during entry. Cluster analysis of infected cells reveals changes in 5-HT₂ receptor cluster attributes, and radial distribution function (RDF) analyses suggest a significant increase in the aggregation of JCPyV particles colocalized with 5-HT₂ receptor clusters in JCPyV-infected samples. These findings provide novel insights into receptor patterning during viral entry and highlight improved technologies for the future development of therapies for JCPyV infection as well as therapies for diseases involving 5-HT₂ receptors.