Weaning Mechanical Ventilation

Weaning from mechanical ventilation (MV) is a gradual process that includes several steps until the complete withdrawal of ventilatory support. Difficult weaning is defined as weaning completed only after the first attempt to withdraw the patient from ventilatory support, that is, a patient who failed the first spontaneous breathing trial (SBT). The use of ultrasound (US) to assess diaphragmatic and extradiaphragmatic muscles, such as the parasternal muscles, has been employed to determine diaphragmatic dysfunction and ventilatory effort, contributing to the decision-making process regarding weaning. Among the tools used for bedside monitoring and evaluation of patients are ventilatory variables that indicate an adequate level of ventilatory assistance in spontaneous modes through ventilatory drive, such as P0.1 (occlusion pressure in the first 100 ms) and assessment of ventilatory effort-inspiratory muscle pressure (Pmus)-which have also contributed to the downscaling of ventilatory support. However, there is still no consensus in the literature regarding predicted values or the effective role of these tools as predictors of weaning during the spontaneous breathing trial (SBT). The available studies investigating the relationship between diaphragmatic US, through measurements of diaphragmatic excursion and thickening fraction, and weaning failure from mechanical ventilation are mostly observational, which limits the strength of the current evidence. Therefore, it is essential to conduct randomized clinical trials, which are still unprecedented on this topic, to more robustly assess the efficacy of this technique as a decision-support tool during the weaning process, thereby contributing to more precise clinical practice. OBJECTIVES: The primary objective of this study is to evaluate the effect of diaphragmatic US use on ventilator-free days in patients with difficult weaning. The secondary objective is to analyze the relationship between the ventilatory variables P0.1 and Pmus, diaphragmatic US, and parasternal muscle recruitment during the SBT. METHODS: This is a randomized clinical trial, following CONSORT recommendations, which will be prospectively registered on the ClinicalTrials platform. Patients will be included after failing the first SBT. Subsequently, they will be randomized into two groups: In the shared US group, the results of diaphragmatic assessment via US will be shared with the attending team for decision-making regarding extubation. In the second group, the non-shared US group, the attending team will not have access to the diaphragmatic assessment for decision-making. EXPECTED RESULTS: It is expected that the shared US group of patients will have a shorter duration of MV and a lower number of extubation failures.

Hypnosis is defined as an altered state of consciousness characterized by an increased susceptibility to suggestion. It is a technique commonly used in the medical field, primarily for the management of pain and anxiety. The literature demonstrates that better pain management is correlated with a shorter length of stay in the ICU and a shorter duration of mechanical ventilation. In patients hospitalized in the ICU requiring invasive mechanical ventilation, the emotional component plays a significant role in dyspnea, which can become an obstacle to weaning from ventilation. The analgesic and anxiolytic treatments used carry numerous side effects and contraindications, limiting their use in ICU patients. Furthermore, pulmonary edema is a common cause of failure to wean from invasive mechanical ventilation. By reducing the occurrence of hypertension and tachycardia, hypnosis could be used as a therapeutic strategy to limit its incidence. Thus, hypnosis could be a valuable therapeutic tool for improving tolerance and the success of ventilator weaning. Although hypnosis is already commonly used in intensive care units, its use is still limited by a lack of evidence for more specific indications. It is in this context that this study was conducted, to assess the feasibility of conducting a hypnosis session during weaning from invasive mechanical ventilation in the intensive care unit.

This is a randomized, open, multicenter, pragmatic, adaptive clinical trial with intention-to-treat analysis. The study will compare two weaning strategies from mechanical ventilation in critically ill patients admitted to intensive care units, with more than 72 hours of mechanical ventilation and with a successful spontaneous breathing trial on pressure support. Immediately after a successful spontaneous breathing trial, eligible patients will be randomized into 2 groups that will be treated according to one of the following interventions:1) One-hour positive pressure ventilation: as soon as the success of the spontaneous breathing trial is confirmed, the patient is submitted to mechanical ventilation for 1 hour using the previous ventilatory parameters and, afterwards, extubated.2) Immediate extubation: the patient is extubated immediately after the success of the spontaneous breathing trial.

This is a randomized, open, multicenter, pragmatic, adaptive clinical trial with intention-to-treat analysis. The study will compare two weaning strategies from mechanical ventilation in critically ill patients admitted to intensive care units, with more than 72 hours of mechanical ventilation and with a successful spontaneous breathing trial on T-piece. Immediately after a successful spontaneous breathing trial, eligible patients will be randomized into 2 groups that will be treated according to one of the following interventions: 1. One-hour positive pressure ventilation: as soon as the success of the spontaneous breathing trial is confirmed, the patient is submitted to mechanical ventilation for 1 hour using the previous ventilatory parameters and, afterwards, extubated. 2. Immediate extubation: the patient is extubated immediately after the success of the spontaneous breathing trial.

Failure of liberation from mechanical ventilation increases days spent being mechanically ventilated, the length of stay and the morbidity of patients. Thus it is crucial that those patients who are ready to be liberated are accurately detected. In this study the investigators want to externally validate an index (the volume-velocity index, VVI) which in a preliminary study was found to predict with high accuracy the outcome of ventilator liberation. In this study, in patients who are deemed ready to undergo weaning by their treating physician the investigators will measure the excursion of the diaphragm, the principal respiratory muscle, the inspiratory time and the tidal volume and the volume breathed by the patient at each respiration in three phases: 1. during pressure support ventilation with 5/5, 2. during pressure support ventilation with 8/0, 3. during t-tube or pressure support ventilation with 0/0. All of these phases are ventilatory modalities widely used during weaning from mechanical ventilation. The investigators will evaluate whether VVI can predict accurately the weaning outcome.