Haemodynamic and Respiratory Effects of a Low Positive End Expiratory Pressure Associated With a Fluid Challenge in Knee-chest Position (OPTIPEP)

Haemodynamic and Respiratory Effects of a Low Positive End Expiratory Pressure Associated With a Fluid Challenge in Knee-chest Position- A Randomized Interventional Study

The genu pectoral position is a surgical position used for spine surgery. This surgical position will lead to physiological hemodynamic and respiratory changes during the procedure.

The knee-pectoral position notably induces an increase in CRF and improves pulmonary ventilation/perfusion ratios. On the other hand, it has been shown that it is accompanied by a reduction in cardiac output of approximately 15% Protective perioperative ventilation including a tidal volume between 6 and 8 ml/kg of theoretical ideal weight, PEEP and alveolar recruitment maneuvers is applied in the operating room to reduce postoperative pulmonary complications. The application of high PEEP and the performance of recruitment maneuvers induce arterial hypotension through changes in intra- and transpulmonary pressures. However, investigators hypothesize that the deleterious hemodynamic effects of PEEP seem to counterbalance its beneficial respiratory effects in this particular position.

The combination of the effects of the knee-pectoral position and protective ventilation could be potentiated and be the cause of the sometimes severe arterial hypotension observed in clinical practice. Since this position improves pulmonary ventilation perfusion ratios, the investigators hypothesized that a lower PEEP and the elimination of intraoperative recruitment maneuvers could be beneficial from a hemodynamic point of view without being deleterious in terms of perioperative pulmonary complications. An exploratory study was carried out at the CAEN University Hospital in 2021 under the name PEEP POSTURE (CLERS Agreement No. 2198 of February 17, 2021) on 90 patients aiming to collect hemodynamic and respiratory parameters in 3 surgical positions: supine decubitus, ventral decubitus , pectoral genu. No difference was found in the evolution of respiratory compliance. On the other hand, a significant drop in SBP, DBP and MAP in the pectoral position was shown compared to the supine group as well as greater vascular filling.

The investigators therefore hypothesize that a reduction in PEEP and optimization of vascular filling could help reduce the adverse effects on blood pressure linked to the surgical position.

Study Overview

• Status: Recruiting
• Conditions: Surgery
• Intervention / Treatment: Procedure: Optimized PEEP

• Study Type: Interventional
• Enrollment (Estimated): 84
• Phase: Not Applicable

Contacts and Locations

Study Locations

• France
  • Caen, France
    • Recruiting
    • Caen University Hospital
    • Contact: Mariam BOUTROS, MD; Phone Number: 02.31.06.31.06; Email: boutros-m@chu-caen.fr

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Patient > 18 years old
• Beneficiary of Social Security or CMU
• Surgical operation under general anesthesia requiring a knee-pectoral position
• Dated and signed informed consent

Exclusion Criteria:

• BMI > 35 kg/m²
• Hemodynamic instability before placing the knee in the pectoral position.
• ASA class IV or V
• Prolonged intervention > 2 hours
• Lack of consent
• Contraindications to the use of esophageal Doppler
• Concomitant third-party clinical trial that may induce a hemodynamic or respiratory change in the patient

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
No Intervention: control group; Standard PEEP (at 7 cmH2o), Vt standardized between [6- 8] ml/kg theoretical ideal weight. Taking NIBP every 3 minutes.
Experimental: Optimized PEEP; Optimized PEEP (at 2 cmH2O), filling according to VES monitoring by esophageal Doppler before reversal, Vt standardized between [6-8] ml/kg theoretical ideal weight. Taking NIBP every 3 minutes.	Procedure: Optimized PEEP; Optimized PEEP

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of occurrences of a MAP	Number of occurrences of a MAP <= 65mmHg per 3 min period occurring during the period of knee pectoral position	baseline

Collaborators and Investigators

• Sponsor: University Hospital, Caen

Study record dates

Study Major Dates

• Study Start (Actual): January 20, 2023
• Primary Completion (Estimated): January 20, 2025
• Study Completion (Estimated): January 30, 2025

Study Registration Dates

• First Submitted: April 15, 2024
• First Submitted That Met QC Criteria: April 19, 2024
• First Posted (Actual): April 22, 2024

Study Record Updates

• Last Update Posted (Actual): April 22, 2024
• Last Update Submitted That Met QC Criteria: April 19, 2024
• Last Verified: April 1, 2024

More Information

Terms related to this study

• Other Study ID Numbers: 22-0219

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No