Clinical trial NCT04399278: End-eXpiratory Occlusion Test to Predict fluId REsponsiveness in the Operating Room (EXPIRE)
Official title: End-eXpiratory Occlusion Test to Predict fluId REsponsiveness in the Operating Room: Prospective Randomized Clinical Trial Comparing Two Occlusion Tests (EXPIRE)
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Hemodynamic Instability
General Anesthesia
Surgery
Protective Mechanical Ventilation
Keywords: End-expiratory occlusion
Fluid responsiveness
Fluid Challenge
Intraoperative monitoring
Hemodynamic optimization
Lead sponsor: University Hospital, Clermont-Ferrand
Sponsor class: OTHER
First posted: 2020-05-22
Enrollment: 40
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Intervention model description: The EEO test will be performed by interrupting the mechanical ventilation at end-expiration over 15 and 30 seconds using the end-expiratory hold button available on the anesthesia ventilator. Each occlusion will be separated by 1 minute to allow a return to the baseline value.

Hemodynamic variables will be recorded before and immediately after each EEO procedure, and after a fluid challenge (4 ml/kg of 0.9% saline over 5 minutes).

Fluid responders will be defined by an increase in stroke volume ≥15% 1 min after the end of the fluid challenge.
Primary purpose: DIAGNOSTIC

Brief summary: The purpose of the study is to evaluate the influence of different durations of the end-expiratory occlusion test to predict fluid responsiveness in mechanically ventilated patients in the operating room.

Detailed description: The reduction of postoperative complications is an essential aspect of care in perioperative medicine.

Many studies have shown that individualized hemodynamic therapy, by optimizing fluid administration and cardiac output, can reduce the risk of postoperative morbidity and mortality.

A fluid challenge, consisting in the administration of a small bolus of intravenous volume of fluid over a short period of time, is one of the commonest therapeutic hemodynamic intervention to test the preload reserve and the cardiac response to an increase in intravascular volume of a patient (fluid responsiveness). However, an increase in stroke volume (or cardiac output) is only achieved in 30 to 50% of patients after a fluid challenge test. Several dynamic tests have been described to predict the response to fluid challenge, however their limits are numerous.

The end-expiratory occlusion (EEO) test, consisting in a brief interruption of mechanical ventilation at end-expiration, by preventing the variation in intra-thoracic pressure, allows an increase in venous return, cardiac preload and stroke volume. Thus, an increase in stroke volume during an EEO can predict fluid responsiveness, simulating a fluid challenge though avoiding the administration of possibly unnecessary fluids.

The EEO test has already been successfully evaluated in several studies in ICU patients. Only few studies were conducted in the operating room, with conflicting findings: one study, consisting of an EEO test of 30 seconds found that changes in stroke volume during an EEO can predict fluid responsiveness, whereas another one, consisting of an EEO test of 15 seconds did not.

The purpose of the study is to evaluate the influence of the duration of EEO test to predict fluid responsiveness in mechanically ventilated patients in operating room.

Eligibility criteria: Inclusion Criteria:

* Adults (age \>18 years)
* Scheduled to undergo planned surgery under general anesthesia
* Surgery requiring invasive arterial and stroke volume monitoring
* Clinical indication to perform a fluid challenge
* Patients able to give informed consent
* Affiliated to a social security scheme

Exclusion Criteria:

* Patient refusal to participate or inability to provide informed consent
* Protected major
* History of lobectomy or pneumectomy
* Patient with reduced left (ejection fraction \< 45%) or right ventricular systolic function
* Arrythmia
* Severe valvulopathy
* Body Mass Index \<15 or \> 40kg/m2
* Contraindication to insertion of invasive arterial line into radial artery
* Emergency surgery
* Pregnancy

Primary outcomes:
measure: To compare the ability of an EEO over 30 sec with that of an EEO over 15 sec to predict fluid responsiveness
timeFrame: During surgery
Secondary outcomes:
Other outcomes:
Locations:
city: Clermont-Ferrand
country: France
facility: CHU
Study officials:
affiliation: University Hospital, Clermont-Ferrand
name: Emmanuel Futier, PhD
role: STUDY_CHAIR
References: