Comparison of Proportional Assist Ventilation Plus, T-Tube Ventilation, and Pressure Support Ventilation as Spontaneous Breathing Trials for Extubation: A Randomized Study.

BACKGROUND: Failure to wean can prolong ICU stay, increase complications associated with mechanical ventilation, and increase morbidity and mortality. The spontaneous breathing trial (SBT) is one method used to assess weaning. The aim of this study was to assess proportional assist ventilation plus (PAV+) as an SBT by comparing its applicability, safety, and efficacy with T-tube and pressure support ventilation (PSV). METHODS: A randomized study was performed involving 160 adult subjects who remained on mechanical ventilation for > 24 h. Subjects were randomly assigned to the PAV+, PSV, or T-tube group. When subjects were ready to perform the SBT, subjects in the PAV+ group were ventilated in PAV+ mode (receiving support of up to 40%), the pressure support was reduced to 7 cm H2O in the PSV group, and subjects in the T-tube group were connected to one T-piece with supplemental oxygen. Subjects were observed for signs of intolerance, whereupon the trial was interrupted. When the trial succeeded, the subjects were extubated and assessed until discharge. RESULTS: The subjects were predominantly male (66.5%), and the leading cause of admission was traumatic brain injury. The groups were similar with respect to baseline characteristics, and no significant difference was observed among the groups regarding extubation success or failure. Analysis of the specificity and sensitivity revealed good sensitivity for all groups; however, the PAV+ group had higher specificity (66.6%) and higher sensitivity (97.6%), with prediction of ∼ 92.1% of the success and failure events. CONCLUSIONS: No significant differences in the groups was observed regarding the rate of extubation failure, duration of mechanical ventilation, and ICU and hospital stay, indicating that PAV+ is an alternative for use as an SBT.

Passive orthostatism (tilt table) in critical patients: Clinicophysiologic evaluation.

PURPOSE: To assess the effects of passive orthostatism on various clinicophysiologic parameters of adult intensive care unit (ICU) patients, by daily placement on a tilt table. MATERIALS AND METHODS: This prospective cohort study was performed in a general ICU. Twenty-three patients 18 years or older, intubated or tracheostomized, without sedation and under weaning from mechanical ventilation, were analyzed. All variables were evaluated at tilting of 30°, 45°, 60°, 75°, and 90°. RESULTS: Glasgow Coma Scale increased during tilt in the first and second day, as well as Richmond Agitation-Sedation Scale. No significant differences were detected in the physiological parameters; however, there was a nonsignificant decrease on the mean arterial pressure at angles of 75° and 90°. The maximum inspiratory pressure significantly increased at 60° compared with 30° on day 1 of the intervention. No significant differences were observed for maximum expiratory pressure, rapid shallow breathing index, and the tidal volume. CONCLUSION: A protocol with daily use of a tilt table for ICU patients is safe and improves the level of consciousness and inspiratory maximum pressure, without causing deleterious acute physiological effects.

Influence of prone positioning on premature newborn infant stress assessed by means of salivary cortisol measurement: pilot study.

OBJECTIVE: This study sought to assess the influence of prone positioning on the stress of newborn premature infants through the measurement of the salivary cortisol concentration and the evaluation of physiological and behavioral responses before and after changes in body positioning. METHODS: Saliva samples were collected from newborn infants at two different times: the first (corresponding to the baseline) after a period of 40 minutes during which the infants were not subjected to any manipulation and were placed in the lateral or supine position, and the second 30 minutes after placement in the prone position. Variables including heart rate, respiratory rate, peripheral oxygen saturation, and the Brazelton sleep score were recorded before, during, and at the end of the period in the prone position. RESULTS: The sample comprised 16 newborn premature infants (56.3% male) with a gestational age between 26 and 36 weeks, postnatal age between 1 and 33 days, birth weight of 935 to 3,050g, and weight at the time of intervention of 870 to 2,890g. During the intervention, six participants breathed room air, while the remainder received oxygen therapy. The median salivary cortisol concentration was lower in the prone position compared to baseline (0.13 versus 0.20; p=0.003), as was the median Brazelton sleep score (p=0.02). The average respiratory rate was lower after the intervention (54.88±7.15 versus 60±7.59; p=0.0004). The remainder of the investigated variables did not exhibit significant variation. CONCLUSION: Prone positioning significantly reduced the salivary cortisol level, respiratory rate, and Brazelton sleep score, suggesting a correlation between prone positioning and reduction of stress in preterm infants.

Delirium during Weaning from Mechanical Ventilation.

Background. We compare the incidence of delirium before and after extubation and identify the risk factors and possible predictors for the occurrence of delirium in this group of patients. Methods. Patients weaned from mechanical ventilation (MV) and extubated were included. The assessment of delirium was conducted using the confusion assessment method for the ICU and completed twice per day until discharge from the intensive care unit. Results. Sixty-four patients were included in the study, 53.1% of whom presented with delirium. The risk factors of delirium were age (P = 0.01), SOFA score (P = 0.03), APACHE score (P = 0.01), and a neurological cause of admission (P = 0.01). The majority of the patients began with delirium before or on the day of extubation. Hypoactive delirium was the most common form. Conclusion. Acute (traumatic or medical) neurological injuries were important risk factors in the development of delirium. During the weaning process, delirium developed predominantly before or on the same day of extubation and was generally hypoactive (more difficult to detect). Therefore, while planning early prevention strategies, attention must be focused on neurological patients who are receiving MV and possibly even on patients who are still under sedation.

Influência do posicionamento em prona sobre o estresse no recém-nascido prematuro avaliada pela dosagem de cortisol salivar: um estudo piloto / Influence of prone positioning on premature newborn infant stress assessed by means of salivary cortisol measurement: pilot study

Objetivo: Avaliar a influência da postura em prona sobre o estresse no recém-nascido prematuro por meio da dosagem do cortisol salivar e da avaliação das respostas fisiológicas e comportamentais, antes e após o posicionamento. Métodos: Foi realizada a coleta de saliva em cada recém-nascido em dois momentos: o primeiro (correspondente ao basal), sem manipulação prévia por 40 minutos, em decúbito lateral ou supino; e o segundo, 30 minutos após o posicionamento em prona. A frequência cardíaca e respiratória, saturação periférica de oxigênio e escala de sono de Brazelton foram registradas antes, durante e ao final do posicionamento em prona. Resultados: Participaram do estudo 16 recém-nascidos prematuros (56,3% masculino) com idade gestacional de 26 a 36 semanas, com 1 a 33 dias de vida, e peso variando de 935 a 3.050g ao nascimento e de 870 a 2.890g no dia da intervenção. Durante o posicionamento, seis recém-nascidos estavam em ar ambiente e os demais recebiam oxigênio suplementar. A mediana dos níveis de cortisol salivar foi menor durante o posicionamento em prona comparativamente ao basal (0,13 e 0,20; p=0,003), assim como a do escore de sono de Brazelton (p=0,02). A média da frequência respiratória foi menor após a intervenção (54,88±7,15 e 60±7,59; p=0,0004). As demais variáveis analisadas não apresentaram variação significativa. Conclusão: O posicionamento em prona diminuiu significativamente os níveis de cortisol salivar, da frequência respiratória e do escore de sono de Brazelton, sugerindo a correlação entre essa postura e a diminuição do estresse nesses recém-nascidos. .

Objective: This study sought to assess the influence of prone positioning on the stress of newborn premature infants through the measurement of the salivary cortisol concentration and the evaluation of physiological and behavioral responses before and after changes in body positioning. Methods: Saliva samples were collected from newborn infants at two different times: the first (corresponding to the baseline) after a period of 40 minutes during which the infants were not subjected to any manipulation and were placed in the lateral or supine position, and the second 30 minutes after placement in the prone position. Variables including heart rate, respiratory rate, peripheral oxygen saturation, and the Brazelton sleep score were recorded before, during, and at the end of the period in the prone position. Results: The sample comprised 16 newborn premature infants (56.3% male) with a gestational age between 26 and 36 weeks, postnatal age between 1 and 33 days, birth weight of 935 to 3,050g, and weight at the time of intervention of 870 to 2,890g. During the intervention, six participants breathed room air, while the remainder received oxygen therapy. The median salivary cortisol concentration was lower in the prone position compared to baseline (0.13 versus 0.20; p=0.003), as was the median Brazelton sleep score (p=0.02). The average respiratory rate was lower after the intervention (54.88±7.15 versus 60±7.59; p=0.0004). The remainder of the investigated variables did not exhibit significant variation. Conclusion: Prone positioning significantly reduced the salivary cortisol level, respiratory rate, and Brazelton sleep score, suggesting a correlation between prone positioning and reduction of stress in preterm infants. .