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BACKGROUND: Patient-ventilator asynchrony is common in patients undergoing mechanical ventilation. The proportion of health-care professionals capable of identifying and effectively managing different types of patient-ventilator asynchronies is limited. A few studies have developed specific training programs, but they mainly focused on improving patient-ventilator asynchrony detection without assessing the ability of health-care professionals to determine the possible causes. METHODS: We conducted a 36-h training program focused on patient-ventilator asynchrony detection and management for health-care professionals from 20 hospitals in Latin America and Spain. The training program included 6 h of a live online lesson during which 120 patient-ventilator asynchrony cases were presented. After the 6-h training lesson, health-care professionals were required to complete a 1-h training session per day for the subsequent 30 d. A 30-question assessment tool was developed and used to assess health-care professionals before training, immediately after the 6-h training lecture, and after the 30 d of training (1-month follow-up). RESULTS: One hundred sixteen health-care professionals participated in the study. The median (interquartile range) of the total number of correct answers in the pre-training, post-training, and 1-month follow-up were significantly different (12 [8.75-15], 18 [13.75-22], and 18.5 [14-23], respectively). The percentages of correct answers also differed significantly between the time assessments. Study participants significantly improved their performance between pre-training and post-training (P < .001). This performance was maintained after a 1-month follow-up (P = .95) for the questions related to the detection, determination of cause, and management of patient-ventilator asynchrony. CONCLUSIONS: A specific 36-h training program significantly improved the ability of health-care professionals to detect patient-ventilator asynchrony, determine the possible causes of patient-ventilator asynchrony, and properly manage different types of patient-ventilator asynchrony. [ABSTRACT FROM AUTHOR]

Background: Weaning and liberation from mechanical ventilation in pediatric patients with tracheostomy and long-term mechanical ventilation constitute a challenging process due to diagnosis heterogeneity and significant variability in the clinical condition. We aimed to evaluate the physiological response during the first attempt of a spontaneous breathing trial (SBT) and to compare variables in subjects who failed or passed the SBT. Methods: This was a prospective observational study in tracheostomized children with long-term mechanical ventilation admitted to the Hospital Josefina Martinez, Santiago, Chile, between 2014-2020. Cardiorespiratory variables such as breathing pattern, use of accessory respiratory muscles, heart rate, breathing frequency, and oxygen saturation were registered at baseline and throughout a 2-h SBT with or without positive pressure depending on an SBT protocol. Comparison of demographic and ventilatory variables between groups (SBT failure and success) was performed. Results: A total of 48 subjects were analyzed (median [IQR] age of 20.5 [17.0-35.0] months, 60% male). Chronic lung disease was the primary diagnosis in 60% of subjects. Eleven (23%) total subjects failed the SBT (< 2 h), with an average failure time of 69 ± 29 min. Subjects who failed the SBT had a significantly higher breathing frequency, heart rate, and end-tidal CO2 than subjects who succeeded (P < .001). In addition, subjects who failed the SBT had significantly shorter duration of mechanical ventilation before the SBT, higher proportion unassisted SBT, and higher rate of deviation SBT protocol in comparison with subjects who succeeded. Conclusions: Conducting an SBT to evaluate the tolerance and cardiorespiratory response in tracheostomized children with long-term mechanical ventilation is feasible. Time on mechanical ventilation before the first attempt and type of SBT (with or without positive pressure) could be associated with SBT failure. [ABSTRACT FROM AUTHOR]

Reverse triggering dyssynchrony is a frequent phenomenon recently recognized in sedated critically ill patients under controlled ventilation. It occurs in at least 30 to 55% of these patients and often occurs in the transition from fully passive to assisted mechanical ventilation. During reverse triggering, patient´s inspiratory efforts start after the passive insufflation by mechanical breaths. The most often referred mechanism is the entrainment of the patient´s intrinsic respiratory rhythm from the brainstem respiratory centers to periodic mechanical insufflations from the ventilator. However, reverse triggering might also occur because of local reflexes without involving the respiratory rhythm generator in the brainstem. Reverse triggering is observed during the acute phase of the disease, when patients may be susceptible to potential deleterious consequences of injurious or asynchronous efforts. Diagnosing reverse triggering might be challenging and can easily be missed. Inspection of ventilator waveforms or more sophisticated methods such as electrical activity of the diaphragm or esophageal pressure can be used for diagnosis. The occurrence of reverse triggering might have clinical consequences. Based on physiological data, reverse triggering might be beneficial or injurious for the diaphragm and the lung depending on the magnitude of the inspiratory effort. Reverse triggering can cause breath-stacking and loss of protective lung ventilation when triggering a second cycle. Little is known about how to manage patients with reverse triggering; however, available evidence can guide management based on physiological principles. [ABSTRACT FROM AUTHOR]

This paper presents a modified equilibrium simulation model for biomass gasification performance prediction. The model, implemented in the MATLAB-SIMULINK[R] environment, is able to calculate the reactor main operating parameters such as reaction temperature, gas composition, gas flow rate and solid product (typically charcoal). The comparison of model output with experimental data puts in evidence the insufficient precision of equilibrium models due to their incapability of taking into account the nonequilibrium effects always present in the gasification process. To obtain a better prediction of measured values, the pure equilibrium model has been modified on the basis of literature experimental data, introducing semi-empirical relations with the aim to consider the most meaningful effects of nonequilibrium. The results demonstrate that this modification leads to an increased precision of the model in reproducing experimental data. [DOI: 10.1115/1.4001463]