Effect of lung volume preservation during spontaneous breathing trial on successful extubation in patients receiving mechanical ventilation: protocol for a multicenter clinical trial.

BACKGROUND: In standard weaning from mechanical ventilation, a successful spontaneous breathing test (SBT) consisting of 30 min 8 cmH2O pressure-support ventilation (PSV8) without positive end-expiratory pressure (PEEP) is followed by extubation with continuous suctioning; however, these practices might promote derecruitment. Evidence supports the feasibility and safety of extubation without suctioning. Ultrasound can assess lung aeration and respiratory muscles. We hypothesize that weaning aiming to preserve lung volume can yield higher rates of successful extubation. METHODS: This multicenter superiority trial will randomly assign eligible patients to receive either standard weaning [SBT: 30-min PSV8 without PEEP followed by extubation with continuous suctioning] or lung-volume-preservation weaning [SBT: 30-min PSV8 + 5 cmH2O PEEP followed by extubation with positive pressure without suctioning]. We will compare the rates of successful extubation and reintubation, ICU and hospital stays, and ultrasound measurements of the volume of aerated lung (modified lung ultrasound score), diaphragm and intercostal muscle thickness, and thickening fraction before and after successful or failed SBT. Patients will be followed for 90 days after randomization. DISCUSSION: We aim to recruit a large sample of representative patients (N = 1600). Our study cannot elucidate the specific effects of PEEP during SBT and of positive pressure during extubation; the results will show the joint effects derived from the synergy of these two factors. Although universal ultrasound monitoring of lungs, diaphragm, and intercostal muscles throughout weaning is unfeasible, if derecruitment is a major cause of weaning failure, ultrasound may help clinicians decide about extubation in high-risk and borderline patients. TRIAL REGISTRATION: The Research Ethics Committee (CEIm) of the Fundació Unió Catalana d'Hospitals approved the study (CEI 22/67 and 23/26). Registered at ClinicalTrials.gov in August 2023. Identifier: NCT05526053.

Biometrical study of the Spanish Colillano pouter / Estudio biométrico del palomo español Buchón colillano / Estudo biométrico da pomba espanhol Buchon colillano

The aim of this study was to find external morphological characters that differentiate sexes in the Colillanopouter, an Spanish local breed. To this end, 37 individuals were studied (16 males and 21 females) from the samebreeder, of which twenty metric variables were obtained. Significant differences (p<0.05) for most of the variables found, thus confirming a marked sexual dimorphism, with the males being significantly bigger than females. By Principal Component Analysis it was deduced that the variables “live weight” and “height” were the more discriminative ones. Which is to say that whereas before 22 values were needed to characterise each individual, now only 2 were necessary. Size was determined by two variables and explained near 90% of the total variance observed.

El objetivo de este estudio fue hallar los caracteres morfológicos externos que diferencian los sexos en el PalomoBuchón Colillano, una raza autóctona española. Para este fin fueron estudiados 37 reproductores (16 machos y 21 hembras) de un mismo criador, de los que se obtuvieron veintidós variables métricas. Se encontraron diferencias significativas (p<0,05) para la mayoría de las variables estudiadas, lo que confirmó un claro dimorfismo sexual, siendo los machos claramente mayores que las hembras. Del análisis de componentes principales fue deducido igualmente quelas variables “peso vivo” y “altura” fueron las más discriminantes, o sea, que donde antes se necesitaban 22 valores para caracterizar a cada individuo, ahora bastan esas dos, explicando el tamaño casi un 90 % de la varianza total observada.

O objetivo deste estudo foi encontrar os caracteres morfológicos externos que diferenciam os sexos na PombaBuchón Colillano, uma raça autóctone espanhola. Para este fim foram estudados 37 reprodutores (16 machos e 21 fêmeas) de um mesmo criador, dos que se obtiveram vinte e dois variáveis métricos. Foram encontradas diferençassignificativas (p<0,05) para a maioria das variáveis estudadas, o que confirmou um claro dimorfismo sexual, sendo os machos claramente maiores que as fêmeas. Da análise de componentes principais foi deduzido igualmente que as variáveis “peso vivo” e “altura” foram as mais discriminantes, ou seja, que onde antes se necessitavam 22 valores para caracterizar a cada individuo, agora bastam essas duas, explicando o tamanho quase 90 % da variação totalobservada. O objetivo deste estudo foi encontrar os caracteres morfológicos externos que diferenciam os sexos naPomba Buchón Colillano, uma raça autóctone espanhola. Para este fim foram estudados 37 reprodutores (16 machos e 21 fêmeas) de um mesmo criador, dos que se obtiveram vinte e dois variáveis métricos. Foram encontradas diferençassignificativas (p<0,05) para a maioria das variáveis estudadas, o que confirmou um claro dimorfismo sexual, sendo os machos claramente maiores que as fêmeas. Da análise de componentes principais foi deduzido igualmente que as variáveis “peso vivo” e “altura” foram as mais discriminantes, ou seja, que onde antes se necessitavam 22 valores paracaracterizar a cada individuo, agora bastam essas duas, explicando o tamanho quase 90 % da variação total observada.