Effectiveness of the endotracheal tube cuff on the trachea: physical and mechanical aspects

Introduction

The inflation pressure of the endotracheal tube cuff can cause ischemia of the tracheal mucosa at high pressures; thus, it can cause important tracheal morbidity and tracheal microaspiration of the oropharyngeal secretion, or it can even cause pneumonia associated with mechanical ventilation if the pressure of the cuff is insufficient.

Objective

In order to investigate the effectiveness of the RUSCH® 7.5 mm endotracheal tube cuff, this study was designed to investigate the physical and mechanical aspects of the cuff in contact with the trachea.

Methods

For this end, we developed an in vitro experimental model to assess the flow of dye (methylene blue) by the inflated cuff on the wall of the artificial material. We also designed an in vivo study with 12 Large White pigs under endotracheal intubation. We instilled the same dye in the oral cavity of the animals, and we analyzed the presence or not of leakage in the trachea after the region of the cuff after their deaths (animal sacrifice). All cuffs were inflated at the pressure of 30 cmH₂O.

Results

We observed the passage of fluids through the cuff in all in vitro and in vivo experimental models.

Conclusion

We conclude that, as well as several other cuff models in the literature, the RUSCH® 7.5 mm tube cuffs are also not able to completely seal the trachea and thus prevent aspiration of oropharyngeal secretions. Other prevention measures should be taken.     

Effects of the compounds resveratrol,rutin, quercetin,and quercetin nanoemulsion on oxaliplatin-induced hepatotoxicity and neurotoxicity in mice

Oxaliplatin (OXA) is a platinum compound widely used in the treatment of some solid tumors, especially colorectal cancer. Despite its usefulness, oxaliplatin-associated neurotoxicity represents the main dose-limiting factor of this drug, and until now, there is no suitable treatment. Chemotherapy with oxaliplatin also increases the rate of developing hepatic damages with inflammatory activity, termed chemotherapy-associated steatohepatitis (CASH). In the present study, we aimed to compare the effects of a series of antioxidant compounds on simultaneous development of oxaliplatin-induced hepato- and neurotoxicity in mice. Mice BALB/c were treated with oxaliplatin for 6 weeks, 10 mg/kg, intraperitoneally, resulting in mechanical allodynia and hepatic steatosis. We administered the following antioxidant compounds—rutin (RT) (20 mg/kg), resveratrol (RVS) (100 mg/kg), quercetin (QT) (20 mg/kg), and quercetin nanoemulsion (NQT) (20 mg/kg)—daily by gavage to BALB/c, and N-acetylcysteine (NAC) was used as positive control. Treatments with RSV, RUT, or NQT were able to prevent mechanical allodynia when compared to the OXA group, and this effect was associated with decreased c-Fos immunopositivity in the lumbar spinal cord. Regarding the effects on steatohepatitis, RVS, QT, and NQT almost completely reversed the mean liver weight increase induced by OXA. In accordance with these previous data, histological evaluation indicated attenuation of all features of hepatic steatosis evaluated in RSV, RUT, QT, and NQT groups. These compounds were able to reduce the immunopositivity for the apoptosis marker caspase-3. On the other hand, only QT and NQT treatments were able to reduce neutrophil migration measured by myeloperoxidase (MPO) activity. These results suggest that the compounds tested, RSV, RUT, QT, and NQT, would be useful for the clinical treatment of neuro- and hepatoxicity induced by oxaliplatin.     

Long-Term Lithium Treatment Reduces Glucose Metabolism in the Cerebellum and Hippocampus of Nondemented Older Adults: An [18F]FDG-PET Study

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