RESUMO
BACKGROUND: A high flow of air applied by large bore nasal cannulae has been suggested to improve symptoms of chronic respiratory insufficiency. In pediatric patients, nasal high-flow (nHF) ventilation was similarly effective compared to noninvasive ventilation with a face mask. OBJECTIVES: The aim of this study was to describe changes in respiratory parameters. METHODS: We measured pressure amplitudes during the respiratory cycle and mean pressures in patients with idiopathic pulmonary fibrosis (IPF) and COPD. In order to achieve tidal volume and minute volume measurements, we used a polysomnography device. Capillary blood was taken for blood gas analysis before and after nHF breathing (8 h). RESULTS: nHF led to an increase in pressure amplitude and mean pressure in healthy volunteers and in patients with COPD and IPF in comparison with spontaneous breathing. In COPD, nHF increased tidal volume, while no difference in tidal volume was observed in patients with IPF. Interestingly, tidal volume decreased in healthy volunteers. Breathing rates and minute volumes were reduced in all groups. Capillary pCO2 decreased in patients with IPF and COPD. CONCLUSIONS: nHF resulted in significant effects on respiratory parameters in patients with obstructive and restrictive pulmonary diseases. The rise in pressure amplitude and mean pressure and the decrease in breathing rate and minute volume will support inspiratory efforts, helps to increase effectiveness of ventilation and will contribute to a reduction in the work of breathing. A CO2 wash-out effect in the upper airway part of the anatomical dead space may contribute to the beneficial effects of the nHF instrument.
Assuntos
Pressão Positiva Contínua nas Vias Aéreas , Fibrose Pulmonar Idiopática/fisiopatologia , Ventilação não Invasiva , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Ventilação Pulmonar/fisiologia , Adolescente , Adulto , Idoso , Resistência das Vias Respiratórias/fisiologia , Estudos de Coortes , Feminino , Humanos , Fibrose Pulmonar Idiopática/terapia , Masculino , Pessoa de Meia-Idade , Doença Pulmonar Obstrutiva Crônica/terapia , Taxa Respiratória/fisiologia , Volume de Ventilação Pulmonar/fisiologia , Adulto JovemRESUMO
We used a rat reinstatement model to test the involvement of dopamine D1- and D2-like receptors in discrete cue-induced reinstatement of food seeking. At a dose that did not alter responding during food self-administration, the D1-like antagonist SCH-23390 blocked reinstatement of food seeking, while the D2-like antagonist eticlopride significantly increased reinstatement responding. Thus, these results establish opposing roles for D1- and D2-like receptors in discrete cue-induced relapse to food seeking.
