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Lung Impedetiometric Modification in SBT and Extubation Failure

Completed
Conditions
Mechanical Ventilation Complication
Weaning Failure
Interventions
Diagnostic Test: Electrical Impedance Tomography (EIT)
Registration Number
NCT03894332
Lead Sponsor
University Magna Graecia
Brief Summary

Weaning is the entire process aimed at liberating patients from mechanical ventilation and endotracheal intubation. Weaning should be considered as early as possible in order to reduce the time spent in invasive mechanical ventilation (iMV), which is associated with morbidity and mortality. To verify if patients are ready to be extubated, a spontaneous breathing trial (SBT) is performed. At this stage some clinical indices and objective parameters are evaluated, such as the breathing pattern, gas exchange, haemodynamic stability and patient's comfort. In case of SBT success, the patient can be extubated. However, a post-extubation respiratory failure can occur within the first 48 hours after extubation, thus making extubation unsuccessful. Some patients considered at risk for post-extubation respiratory failure benefit from the application of non-invasive ventilation (NIV) after extubation. Early characterization of these patients is crucial to improve their clinical outcomes.

Electrical Impedance Tomography (EIT) has been introduced in clinical practice as a non-invasive bedside monitoring tool to evaluate the aeration and ventilation of different lung regions. EIT has been proposed to guide ventilator settings adjustments in critically ill patients and to monitor prolonged weaning. However, the potential of EIT to assess SBT and after extubation in a general ICU population has never been evaluated insofar.

The present study aims to describe the modifications of lung aeration, ventilation and inhomogeneity occurring during SBT and after extubation in a general population of critically ill patients at the first SBT attempt.

Detailed Description

Not available

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
80
Inclusion Criteria
  • Glasgow Coma Scale ≥8
  • presence of clearly audible cough during suctioning with need for tracheal suctioning ≤2/hour
  • normal sodium blood values
  • core temperature <38.5° during the previous 8 hours
  • Arterial partial pressure of oxygen to inspired oxygen fraction (PaO2/FiO2) ≥200 mmHg, with a Positive End Expiratory Pressure ≤5 cmH2O and FiO2 ≤0.4
  • stable cardiovascular status (i.e., HR ≤140 beats/min, sBP between 90 and 160 mmHg without need for vasopressin, epinephrine or norepinephrine infusion, or with dopamine or dobutamine infusion ≤5 mcg/kg/min)
  • cuff leak volume >110 mL
Exclusion Criteria
  • major heart arrhythmias or cardiac ischemia
  • pneumothorax or emphysema
  • recent (1 week) thoracic surgery
  • presence of chest burns
  • pregnancy
  • inclusion in other research protocols

Study & Design

Study Type
OBSERVATIONAL
Study Design
Not specified
Arm && Interventions
GroupInterventionDescription
SBT SuccessElectrical Impedance Tomography (EIT)Patients took part of this cohort when succeeding the Spontaneous Breathing Trial (SBT).
SBT FailureElectrical Impedance Tomography (EIT)Patients took part of this cohort when failing the Spontaneous Breathing Trial (SBT). SBT Failure is defined by one or more of the following criteria occurring during the SBT: 1. loss of ≥ 2 points of Glasgow Coma Scale 2. respiratory rate/ tidal volume ≥105 breaths/min/L 3. arterial partial pressure of oxygen ≤60 mmHg on inspired oxygen fraction (FiO2) ≥0.5 and/or pH \<7.32 or a decrease in pH ≥0.07 units at the end of the SBT 4. systolic Blood Pressure \<90 mmHg or ≥180 mmHg or increased by ≥20% 5. Heart Rate \>140 beats/min or increased by 20% 6. onset of major heart arrhythmias, or electrocardiographic signs of cardiac ischemia 7. Respiratory Rate ≥35 breaths/min or increased by ≥50% 8. increased effort, respiratory distress (as indicated by diaphoresis, accessory respiratory muscles recruitment, facial signs of distress and/or paradoxical breath)
Extubation FailureElectrical Impedance Tomography (EIT)Need for continuous positive airways pressure (CPAP), non invasive ventilation (NIV) or reintubation within 48 hours from extubation, as defined by: 1. Respiratory Rate \>25 breaths/min for 2 hours 2. Heart Rate \>140 beats/min or sustained increase or decrease \>20% 3. clinical signs of respiratory muscle failure 4. arterial partial pressure of oxygen (PaO2) \<80 mmHg on inspired oxygen fraction (FiO2) ≥50% 5. Arterial partial pressure of carbon dioxide \>45 mmHg with pH \<7.33
Extubation SuccessElectrical Impedance Tomography (EIT)Patients took part of this cohort when, after extubation, did not need continuous positive airways pressure (CPAP), non invasive ventilation (NIV) or reintubation within 48 hours.
Primary Outcome Measures
NameTimeMethod
Change of tidal volume in percentage (dVt%) from baseline after 5 minutes from extubation (SB_0)At 5 minutes after extubation (SB_0)

change from baseline, expressed in percentage, of the end expiratory lung volume as assessed through electrical impedance tomography

Inhomogeneity Index (GI) at baselineAt baseline during Pressure Support Ventilation

Inhomogeneity Index (GI) as assessed through electrical impedance tomography

Change of end-expiratory lung impedance (dEELI) from baseline at first 5 minute of Spontaneous Breathing Trial (SBT_0)At 5 minutes of Spontaneous Breathing Trial (SBT)

change from baseline, expressed in mL, of the end expiratory lung volume as assessed through electrical impedance tomography

Change of end-expiratory lung impedance (dEELI) from baseline at last 30 minute after extubation (SB_30)At 30 minutes after extubation

change from baseline, expressed in mL, of the end expiratory lung volume as assessed through electrical impedance tomography

Change of tidal volume in percentage (dVt%) from baseline at last 5 minute of SBT (SBT_0)At 5 minutes of spontaneous breathing trial (SBT_0)

change from baseline, expressed in percentage, of the end expiratory lung volume as assessed through electrical impedance tomography

Change of tidal volume in percentage (dVt%) from baseline from baseline at 30 minute of Spontaneous Breathing Trial (SBT_30)At the last 5 minutes of Spontaneous Breathing Trial (SBT) (SBT_30)

change from baseline, expressed in percentage, of the end expiratory lung volume as assessed through electrical impedance tomography

Change of tidal volume in percentage (dVt%) from baseline at last 30 minute after extubation (SB_30)At 30 minutes after extubation (SB_30)

change from baseline, expressed in percentage, of the end expiratory lung volume as assessed through electrical impedance tomography

Inhomogeneity Index (GI) after 30 minutes of the Spontaneous Breathing Trials (SBT_30)At 30 minutes of Spontaneous Breathing Trial (SBT_30)

Inhomogeneity Index (GI) as assessed through electrical impedance tomography

Inhomogeneity Index (GI) after 30 minutes from extubation (SB_30)At 30 minutes after extubation (SB_30)

Inhomogeneity Index (GI) as assessed through electrical impedance tomography

Change of end-expiratory lung impedance (dEELI) from baseline at last 5 minute of Spontaneous Breathing Trial (SBT_30)At the last 5 minutes of Spontaneous Breathing Trial (SBT)

change from baseline, expressed in mL, of the end expiratory lung volume as assessed through electrical impedance tomography

Change of end-expiratory lung impedance (dEELI) from baseline at first 5 minute after extubation (SB_0)At 5 minutes after extubation

change from baseline, expressed in mL, of the end expiratory lung volume as assessed through electrical impedance tomography

Inhomogeneity Index (GI) after 5 minutes of the Spontaneous Breathing Trials (SBT_0)At 5 minutes of Spontaneous Breathing Trial (SBT_0)

Inhomogeneity Index (GI) as assessed through electrical impedance tomography

Inhomogeneity Index (GI) after 5 minutes from extubation (SB_0)At 5 minutes after extubation (SB_0)

Inhomogeneity Index (GI) as assessed through electrical impedance tomography

Secondary Outcome Measures
NameTimeMethod
the ratio between respiratory rate (RR) and tidal volume (Vt) (RR/Vt) at 5 minutes after extubation (SB_0)At 5 minutes after extubation (SB_0)

the ratio between respiratory rate (RR) and tidal volume (Vt) (RR/Vt)

the ratio between respiratory rate (RR) and tidal volume (Vt) (RR/Vt) at 30 minutes after extubation (SB_30)At 30 minutes after extubation (SB_30)

the ratio between respiratory rate (RR) and tidal volume (Vt) (RR/Vt)

Arterial Blood Gases at baselineAt baseline during Pressure Support Ventilation

Arterial Blood was sampled for gas analysis

Arterial Blood Gases at SBT_30At 30 minutes of Spontaneous Breathing Trial (SBT_30)

Arterial Blood was sampled for gas analysis

Arterial Blood Gases at SB_30At 30 minutes after extubation (SB_30)

Arterial Blood was sampled for gas analysis

the ratio between respiratory rate (RR) and tidal volume (Vt) (RR/Vt) at baselineAt baseline during Pressure Support Ventilation

the ratio between respiratory rate (RR) and tidal volume (Vt) (RR/Vt)

the ratio between respiratory rate (RR) and tidal volume (Vt) (RR/Vt) at SBT_30At 30 minutes of Spontaneous Breathing Trial (SBT_30)

the ratio between respiratory rate (RR) and tidal volume (Vt) (RR/Vt)

the ratio between respiratory rate (RR) and tidal volume (Vt) (RR/Vt) at 5 minutes of Spontaneous Breathing Trial (SBT_0)At 5 minutes of Spontaneous Breathing Trial (SBT_0)

the ratio between respiratory rate (RR) and tidal volume (Vt) (RR/Vt)

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