Serial Daily Diaphragm Ultrasounds in Ventilated Patients

Study Overview
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Brief Summary
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When a person is put on a breathing machine the investigators think that the breathing muscles can get weaker. The investigators are not sure how quickly this happens but in some people this leads to problems when they try to breathe on their own without the breathing machine. The diaphragm is at the bottom of a person's chest separating their lungs from what is in their belly and it is a very strong muscle. In fact, it is main muscle that one uses for breathing. An ultrasound machine is a painless way to see what is happening beneath the skin. It is safe and easy to do. Using an ultrasound the investigators are planning to measure how thick the diaphragm is and how much it changes while a person is on a breathing machine in the ICU. Getting a better understanding of this condition could lead to improved treatments that might help support patients who require a ventilator for breathing. The investigators hypothesis is that patients for whom the breathing machine is doing all of the work of breathing, will have their diaphragm thickness gradually decrease and changing to a breathing modem mode where they have to put in more effort the diaphragm thickness will start increasing again.

Detailed Description
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The investigators propose to expand the investigators single-centre longitudinal pilot study into a complete study in which the investigators will use B-mode ultrasonography to evaluate daily changes in diaphragm thickness in all critically ill patients on mechanical ventilation (MV) until successful weaned from MV. The impact of patient age, co-morbidities, and the use of various modes of ventilation on diaphragm thickness will be assessed. Diaphragmatic thickness and its change from baseline will be evaluated as predictors of the need for a prolonged wean (>7days). The investigators hypothesize that in patients on mandatory mode ventilation, diaphragmatic thickness will progressively decrease. Switching from mandatory to assisted breathing modes will correlate with increases in diaphragmatic thickness.

Official Title
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Serial Ultrasonographic Evaluation Of Diaphragm Thickness During Mechanical Ventilation In ICU Patients

Conditions
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Muscle Atrophy or Weakness, Ventilator-associated Lung Injury

Intervention / Treatment
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* Procedure: Ventilation- mandatory
* Procedure: Ventilation- voluntary mode only
* Procedure: Voluntary with preceding mandatory


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: All patients age ≥19 years in the ICU on ventilation Exclusion Criteria: History of diaphragmatic or neuromuscular disease On a home ventilator History of diaphragm surgery Absence of adequate initial US images (3 consecutive days with at least 2 operators) BMI greater than 40

Ages Eligible for Study
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Minimum Age: 19 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Ventilation- mandatory mode only<br>those patient ventilator days during which they had only received a mandatory mode of ventilation | Procedure: Ventilation- mandatory<br>* Patient days during which only a mandatory ventilation mode was used and prior to this no voluntary mode was used.<br>|
| Ventilation- voluntary mode only<br>Those patient days on a mechanical ventilator who have not received prior mandatory ventilation during this episode of mechanical ventilation. | Procedure: Ventilation- voluntary mode only<br>* Patient days on a voluntary mode with no preceding days with a majority of time spend on a mandatory mode<br>|
| voluntary with preceding mandatory<br>Those patient ventilator days where the patient had at least one prior day of mandatory mechanical ventilation during this episode of respiratory support. | Procedure: Voluntary with preceding mandatory<br>* Patient days on a voluntary vent mode with at least one day prior during which the majority of the vent mode was mandatory.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| US measurement of diaphragm and quadriceps thickness | Diaphragm thickness will be measured once per day and continue until extubation, liberation from mechanical ventilation, transfer to another facility, death, or study completion. | Participants will be ultrasounded daily until they are extubated or the 3 month study period has ended, the expected average duration of mechanical ventilation is 4.4 days at our institution | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Quadriceps muscle thickness | The thickness of the quadriceps muscle on ultrasound will be measured daily until patient exit from study | Participants will be ultrasounded daily until they are extubated or the 3 month study period has ended, the expected average duration of mechanical ventilation is 4.4 days at our institution | 
| PEEP (Postive end expiratory pressure) applied by the mechanical ventilator at the time of the ultraspound | The PEEP (as described above in the title) in cm H20 as applied by the mechanical ventilator, measured at the time of ultrasound | Participants will be ultrasounded daily until they are extubated or the 3 month study period has ended, the expected average duration of mechanical ventilation is 4.4 days at our institution | 
| re-intubated within 48 hours | Whether a patient required re-intubation within 48 hours of extubation | followed for 48 hours post extubation, or 3 month study period has ended | 
| mean daily fluid balance | Fluid balance of administer fluids minus measurable excreted fluid as recorded every 24 hours by the bedside nurse | Will be recorded daily until they are extubated or the 3 month study period has ended, the expected average duration of mechanical ventilation is 4.4 days at our institution | 
| mean daily FiO2 (oxygen level administered) | The daily average oxygen delivered through the mechanical ventilator to the patient. | Will be recorded daily until they are extubated or the 3 month study period has ended, the expected average duration of mechanical ventilation is 4.4 days at our institution | 
| mode of mechanical ventilation for >80% of the day | Mode of mechanical ventilation for the >80% of the day will be recorded here. This will be split into a mandatory mode (where the machine supplies a breath) or a voluntary mode (where the patient triggers the breath and the machine supports it). | Will be recorded daily until they are extubated or the 3 month study period has ended, the expected average duration of mechanical ventilation is 4.4 days at our institution | 
| steroids given | This will include any dose of steroids administered to the patient each day during their intubation. | Will be recorded daily until they are extubated or the 3 month study period has ended, the expected average duration of mechanical ventilation is 4.4 days at our institution | 
| vasopressors given | This will include any dose of medications to support the blood pressure (norepinephrine, epinephrine, dopamine, dobutamine, amrinone) administered to the patient each day during their intubation. | Will be recorded daily until they are extubated or the 3 month study period has ended, the expected average duration of mechanical ventilation is 4.4 days at our institution | 
| paralytics given | This will include any dose of paralytic medication administered to the patient each day during their intubation, except given as part of their initial intubation | Will be recorded daily until they are extubated or the 3 month study period has ended, the expected average duration of mechanical ventilation is 4.4 days at our institution | 
| 30 day mortality | This is to capture all cause mortality. A patient will be considered to have survived if they are discharged from hospital. | 30 days after patient is extubated, or at the end of the follow up period 1 month after the 3 month study has ended | 
| Body Mass Index (BMI) | The standard BMI will be recorded as determined by the clinical dietician. | from admission information, at the time of admission to the ICU, obtained from the patient record | 
| presence of sepsis/severe sepsis on admission | This will be determined as positive if there is any reference to infection in the patients admitting paperwork in conjunction with the classic SIRS (systemic inflammatory response syndrome) criteria. | from admission information, at the time of admission to the ICU, obtained from the patient record. | 
| % Caloric goals met in preceding 24 hours | A % of caloric goals delivered over the preceding 24 hours will be captured | Will be recorded daily until they are extubated or the 3 month study period has ended, the expected average duration of mechanical ventilation is 4.4 days at our institution | 
| Initial presence of malnutrition | Presence of malnutrition as assessed by dietician on admission | Measure at the time of admission to the ICU | 
| At risk for re-feeding syndrome | Presence of risk for re-feeding syndrome as assessed by dietician on admission | Assessed on admission to the ICU | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Atrophy, Ventilator, Induced, Diaphragm, Dysfunction