Clinical Trial: Respiratory Mechanics and Patient-ventilator Asynchrony Index in Patients With Invasive Mechanical Ventilation

Study Status: Recruiting
Recruit Status: Recruiting
Study Type: Observational

Official Title: Respiratory Mechanics and Patient-ventilator Asynchrony Index in Patients With Invasive Mechanical Ventilation

Brief Summary: The objective of the study is to estimate the incidence of asynchrony and to assess its relationship with respiratory mechanics. This will be a prospective cohort study, including patients under invasive mechanical ventilation. Within 48h post intubation, the investigators will record the values of intrinsic positive end-expiratory pressure, pulmonary compliance and resistance. Participants will be followed up from intubation to mechanical ventilation liberation. The investigators will register clinical signs of asynchrony and record ventilator waveforms continuously and quantify patient-ventilator asynchrony. The investigators will calculate the total asynchrony index (AI) and of each asynchrony type (ineffective triggering, double triggering, auto triggering, short cycling and prolonged cycling). Participants will be followed up until hospital discharge.

Detailed Summary: Patient-ventilator asynchrony is common in patients under invasive mechanical ventilation, present between 10 and 80% of all respiratory cycles, and is associated with adverse clinical outcomes, such as delay in the weaning process, increased complications of mechanical ventilation, with possible impact on survival. The objective of this study is to estimate the incidence of asynchrony and to assess its relationship with respiratory mechanics. This will be a prospective cohort study, including all patients under invasive mechanical ventilation admitted at Respiratory ICU at Hospital das Clínicas da Faculdade de Medicina da Universidade de Sao Paulo (USP), during the study period. Within 48h post intubation, the investigators will record the values of intrinsic positive end-expiratory pressure, pulmonary compliance and resistance. Participants will be followed up from intubation to mechanical ventilation liberation. The investigators will register clinical signs of asynchrony and record ventilator waveforms continuously. The ventilator waveforms will be captured directly from ventilator and processed by dedicated software, without direct contact with patients. Later, ventilator waveforms will be analyzed to quantify patient-ventilator asynchrony. The investigators will calculate the total asynchrony index (AI) and of each asynchrony type (ineffective triggering, double triggering, auto triggering, short cycling and prolonged cycling). Participants will be followed up until hospital discharge, and the investigators will record duration of mechanical ventilation, the use of non-invasive ventilation post-extubation, reintubation, tracheostomy, ICU and hospital length of stay and survival. With this project, the investigators will estimate the incidence and magnitude of patient-ventilator asynchrony and its association with clinical outcomes
Sponsor: University of Sao Paulo General Hospital

Current Primary Outcome: asynchrony index [ Time Frame: from study inclusion until the date of extubation or date of death from any cause, whichever comes first, up to 28 days ]

asynchrony index will be calculated as the number of major asynchrony events divided by total number of respiratory cycles


Original Primary Outcome: Same as current

Current Secondary Outcome:

  • Clinical signs of patient-ventilator asynchrony [ Time Frame: daily, from study inclusion until the date of extubation or date of death from any cause, whichever comes first, up to 28 days ]
    a standardized questionnaire will be used to evaluate the presence of clinically significant patient-ventilator asynchrony. Trained investigators will observe participant´s breathing pattern and other clinical signs of patient-ventilator asynchrony and score each item as absent (0) or present (1). Then, they will visual inspection of ventilator waveforms on the ventilator screen for a 5 minute observation period, looking for missed efforts, double triggering, auto-triggering, cycling delay and premature cycling, as previously defined. If they observe more than 1 asynchrony event for every 10 respiratory cycles, they will rate this item as present (1), otherwise, they will rate it as absent (0).
  • ventilation free-days [ Time Frame: 28 days ]
    number of days alive and off the ventilator up to day 28
  • tracheostomy rate [ Time Frame: up to 90 days ]
    performance of surgical or bronchoscopy-guided tracheotomy
  • Survival rate [ Time Frame: at 28 and 90 days ]
    survival from intubation up to 90 days


Original Secondary Outcome: Same as current

Information By: University of Sao Paulo General Hospital

Dates:
Date Received: January 18, 2016
Date Started: August 2016
Date Completion: July 2018
Last Updated: March 31, 2017
Last Verified: August 2016