Considerable asynchrony during pressure-support ventilation has been reported. While the beginning of active inspiration is usually identifiable in the airway pressure (Paw) curve (the inspiratory trigger), there is still a need for accurate, non-invasive methods to identify the end of inspiration. To test the hypothesis that inspiration, particularly the end of inspiration, can be estimated from the Paw curve, we compared indirect measurements based on Paw with simultaneous direct electromyography of the diaphragm (EMGdi).We prospectively studied 10 patients during the weaning period after cardiac surgery. Inspiratory pressure support was set at 20, 15, 10, and 5 cm H(2)O; 25 respiratory cycles were analyzed at each pressure level. Recording of the electromyogram was obtained with electrodes inserted into the diaphragm during surgery.The start and end of inspiration were identified in the Paw curve in 99% and 98% of the 1000 cycles analyzed, respectively, and were coincident with the electromyogram in 62% and 53% of the cycles, respectively. The inspiratory time estimated from the Paw curve was well correlated (r=0.94, P<0.0001) with the electromyogram.The end of neural inspiration (EMGdi) can be easily and with little error recognized from the Paw curve alone in patients with normal ventilatory mechanics who receive pressure-support ventilation.

Diaphragm (acoustics)

Pressure support ventilation

Respiratory physiology

Artificial ventilation

Spontaneous breathing trial

Source

Cite

Citations (2)

La ‘fila’ de agua valenciana y otras medidas de aforo. La verdadera naturaleza de un sistema de medición de caudales de origen andalusí

Espacio Tiempo y Forma Serie III Historia Medieval (2021)

Ferran Esquilache Martí

Los caudales de agua de riego se han medido tradicionalmente en Valencia mediante una medida de aforo llamada fila, de la que hasta ahora se desconocía su verdadera naturaleza y valor, a pesar de ser un tema ampliamente discutido desde hace siglos. En este artículo se plantea una solución a esta discusión, estableciéndose que la fila o hila, de herencia andalusí, tenía una triple condición según la cantidad de agua disponible. Así, habitualmente era la cantidad de agua que podía pasar por un orificio con una medida concreta, cuando disminuía el nivel era una cantidad de agua proporcional a toda la disponible, y si había mucha escasez era una cantidad de tiempo durante el cual disponer de toda el agua. Además, se establece cual fue el valor de la fila en Valencia en época medieval y moderna, su posible equivalencia con otras medidas de aforo, y se propone cual fue su valor en época andalusí, antes de la conquista.

10.5944/etfiii.34.2021.28668

Cite

Citations (2)

Arrhythmogenic effects of antiarrhythmic drugs in patients with an old myocardial infarction and asymptomatic ventricular ectopic activity as studied by programmed electrical stimulation

European Heart Journal (1987)

Jerónimo Farré A Grande P. S. Albo Ferran Esquilache Martí Pedro Martínez-Romero

In 22 patients with a previous myocardial infarction and documented Lown class II to IV asymptomatic ventricular arrhythmias, the arrhythmogenic effect of mexiletine (18 patients) and propafenone (10 patients) has been assessed by programmed electrical stimulation. Ventricular arrhythmias induced during the basal study were: repetitive ventricular responses (RVR) (11/22, 50%), nonsustained ventricular tachycardia (VT) (3/22, 14%), sustained VT (7/22, 32%) and ventricular fibrillation (VF) (1/22, 4%). The induction of sustained VT or VF increased to 50% after mexiletine and to 80% following propafenone. An arrhythmogenic effect was found in 7/11 patients (64%) without VT at the control study (P = 0.004). One patient of this group spontaneously developed sustained VT both after mexiletine and propafenone. Only 1/8 patients (13%) with sustained VT/VF at the basal study had RVR after drug administration. The R-R interval of sustained VT at the basal state tended to be faster than that after the drugs (260 +/- 60 ms vs 293 +/- 56 and 332 +/- 77 ms for mexiletine and propafenone, respectively) (P = 0.052). Statistical significance was only reached in the propafenone group (P = 0.03). Facilitation of VT induction after antiarrhythmic drugs is most likely due to a modest lengthening of refractoriness in contrast with a more evident reduction in conduction velocity within the reentry pathway. Our study illustrates that treating asymptomatic ventricular ectopic activity in patients with an old myocardial infarction may be dangerous and that antiarrhythmic drugs show a significant arrhythmogenic potential at least in the laboratory setting.

10.1093/eurheartj/8.suppl_a.113

Cite

Citations (6)