Use of Heart-lung Interaction to Predict Haemodynamic Tolerance to the Open Lung Approach With Individualised PEEP

Study Overview
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Brief Summary
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This is an observational, prospective, single-centre study that will focus on patients undergoing major non-cardiac surgery requiring invasive mechanical ventilation and invasive blood pressure monitoring Hypotheses: A positive TVC (tidal volume challenge) prior to the recruitment manoeuvre (RM) predicts a decrease in CI within 5 minutes of individualised PEEP establishment of at least 10%. T0: Moment prior to the start of tidal volume challenge. Baseline values T1: After tidal volume challenge, moment priorate the start of the recruitment manoeuvre (RM). Mostcare and ventilator values. T2: At minute 5 of establishing individualised PEEP. All parameters derived from basic monitoring, Mostcare, Masimo and ventilator monitoring shall be monitored and recorded. Record whether any fluid bolus has been administered. T3: At minute 30 of establishing individualized PEEP. Blood gases and Masimo values.

Detailed Description
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This is an observational, prospective, single-centre study that will focus on patients undergoing major non-cardiac surgery requiring invasive mechanical ventilation and invasive blood pressure monitoring Lung recruitment manoeuvres (RM) are performed to prevent collapsed lung parenchyma from compromising oxygenation. In order to open collapsed lung areas, intrathoracic pressure needs to be raised and this may have haemodynamic repercussions especially in patients with an overt or latent hypovolaemic state. Parameters such as stroke volume variation (SVV) or pulse pressure variation (PPV) reflect to some extent the heart-lung interaction and have been used as predictors of fluid responsiveness by exploiting this principle to detect preload-dependent patients. The tidal volume challenge (TVC) uses the same principle of heart-lung interaction with better results. TVC can be a predictor of haemodynamic tolerance to RM + individualised PEEP. Hypotheses: A positive TVC prior to the recruitment manoeuvre (RM) predicts a decrease in CI within 5 minutes of individualised PEEP establishment of at least 10%. Data will be collected in the surgical area. Demographic and clinical parameters will be collected from the patient's clinical history, respiratory parameters obtained from the respirator, haemodynamic parameters obtained from the Mostcare and Masimo devices, oxygenation parameters and parameters obtained from blood gas analysis before and after a recruitment manoeuvre. If the patient meets all inclusion criteria and none of the exclusion criteria, he/she will be included for data collection. If he/she benefits from a recruitment manoeuvre (air-test + clinical indication), which will be assessed by clinical indications, he/she will be entered into our study. All measurements will be taken under stable haemodynamic conditions (HR and MAP should be stable and with +-10% variation for 1 min prior to measurements), without administration of vasoactive drugs or influential surgical aggression at that time. When the recruitment manoeuvre (RM) is performed, we will monitor all the variables by setting the following time points: T0: Moment prior to the start of recruitment manoeuvre. All the variables described (Mostcare, blood gases, ventilator, Masimo, basic monitoring) and the administration of fluids prior to the manoeuvre shall be monitored. To avoid artefacts on the arterial waveform, a fast-flush test and assessment of dP/dtMAX should always be performed. Patients who do not have optimal arterial waveform morphology at this point will be excluded. T1: At minute 1 after starting the VTC, the parameters derived from the basic monitoring and the Mostcare will be checked. From this moment on, the parameters obtained from Mostcare will be analysed continuously (minute by minute) until 15 minutes after establishing the individualised PEEP. T2: At minute 5 of establishing individualised PEEP. All parameters derived from basic monitoring, Mostcare, Masimo and ventilator monitoring shall be monitored and recorded. Record whether any fluid bolus has been administered. T3: Within 30 minutes of establishing individualised PEEP, venous and arterial blood gases shall be drawn. Record whether any fluid bolus has been administered.

Official Title
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Use of Heart-lung Interaction Parameters to Predict Haemodynamic Tolerance to the Open Lung Approach With Individualised PEEP During Invasive Mechanical Ventilation in the Operating Room

Conditions
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Hypovolemia, Anesthesia, Perioperative/Postoperative Complications, Haemodynamic Instability

Intervention / Treatment
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* Diagnostic Test: Tidal Volume Challenge
* Procedure: Recruitment maneuver obtaining individualised PEEP


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients over 18 years of age; undergoing scheduled non-cardiothoracic surgery; under controlled invasive mechanical ventilation and invasive arterial monitoring; supine position. Exclusion Criteria: Chronic pulmonary disease (defined as chronic obstructive pulmonary disease grade 3 or higher or any disease requiring long-term oxygen therapy); congenital cardiac malformations; severe valvular heart disease; heart failure NYHA (New York Heart Association) Grade III/IV; arrhythmias; history of reduced ventricular systolic function (FEVI <40% or TAPSE <17 cm/s); history of pulmonary hypertension; BMI >35 (due to altered lung compliance and rib cage); heart rate/respiratory rate ratio < 3.6; presence of inspiratory effort; open chest; increased intra-abdominal pressure (due to pathology or pneumoperitoneum); altered pulmonary or rib cage compliance due to surgery (trendelemburg or antitrendelemburg position); uncorrected optimal arterial waveform (resonant or damped) and presence of any contraindication to lung recruitment manoeuvres. The latter are: pulmonary emphysema, pulmonary bullae, uncontrolled haemodynamic instability, right heart failure, elevated intracranial pressure (decreased return flow through jugular veins) or lack of monitoring if necessary, bronchospasm, undrained pneumothorax.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 90 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| POSITIVE Tidal Volume Challenge<br>Population with positive result in the tidal volume challenge. That is, an increase in PPV greater than 2% after increasing the tidal volume from 6 ml/kg to 8 ml/kg for 1 minute. | Diagnostic Test: Tidal Volume Challenge<br>* The tidal volume challenge is a fluid response test that consists of increasing the tidal volume from 6 ml/kg to 8 ml/kg for 1 minute and evaluating PPV. If PPV increases by more than 2%, it is considered positive, otherwise it will be negative.<br>Procedure: Recruitment maneuver obtaining individualised PEEP<br>* The alveolar recruitment maneuver is a well-studied procedure to open the lung during invasive mechanical ventilation, allowing us to achieve the best PEEP for that lung, which is individualised PEEP.<br>|
| NEGATIVE Tidal Volume Challenge<br>Population with a negative result in the tidal volume challenge. That is, not enough increase in PPV. | Diagnostic Test: Tidal Volume Challenge<br>* The tidal volume challenge is a fluid response test that consists of increasing the tidal volume from 6 ml/kg to 8 ml/kg for 1 minute and evaluating PPV. If PPV increases by more than 2%, it is considered positive, otherwise it will be negative.<br>Procedure: Recruitment maneuver obtaining individualised PEEP<br>* The alveolar recruitment maneuver is a well-studied procedure to open the lung during invasive mechanical ventilation, allowing us to achieve the best PEEP for that lung, which is individualised PEEP.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Tidal volume challenge as a predictor of haemodynamic tolerance to recruitment maneuver with individualized PEEP at minute 5 after recruitment maneuver | To describe the relationship between baseline TVC and the difference in baseline and 5-minute CI (cardiac index) after RM with individualised PEEP. We consider a 10% decrease in CI as clinically significant. | At minute 5 after recruitment maneuver | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Tidal volume challenge as a predictor of haemodynamic tolerance to recruitment maneuver with individualized PEEP at different moments in time | To describe the relationship between baseline TVC and the difference in DO2 (cardiac index) at baseline and at 1 and 30 minutes after RM with individualised PEEP acquisition. | For 30 minutes from the recruitment maneuver | 
| Stroke Volume Variation and Pulse Pressure Variation as predictors of haemodynamic tolerance to recruitment maneuver with individualized PEEP at different moments in time | To describe the relationship between baseline PPV-SVV and the difference in CI (cardiac index) and DO2 at baseline and at 1, 5 and 30 minutes after RM with individualised PEEP acquisition. | For 30 minutes from the recruitment maneuver | 
| Pressure Rating Analytical Method (PRAM) for monitoring haemodynamic effect of the Open Lung Approach with individualized PEEP | To describe the effect of OLA (Open Lung Approach) with individualised PEEP on haemodynamic parameters obtained with minimally invasive monitoring using the PRAM method continuously during the first 15 minutes after RM with individualised PEEP compared to baseline values of: indexed systolic volume (ISV), cardiac index (CI), oxygen delivery (DO2), pulse pressure variation (PPV), dynamic arterial elastance (EaDyn), cardiovascular system impedance (z), dP/dtMAX and cardiac cycle efficiency (CCE). | For 15 minutes from the recruitment maneuver | 
| Compare invasive with non-invasive monitoring for blood oxygenation | To establish relationships between invasive and non-invasive parameters with similar physiological bases such as PaO2 and Ori | Before and at minute 30 after recruitment maneuver | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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PEEP, Tidal Volume Challenge, Recruitment Maneuver, Haemodynamic monitoring, Heart-lung interactions, Stroke Volume Variation, Pulse Pressure Variation, Cardiac Index