Detecting Lung's Closing Pressure by Capnography

NCT ID: NCT05873998

Last Updated: 2025-05-16

Basic Information

• Recruitment Status: COMPLETED
• Total Enrollment: 20 participants
• Study Classification: OBSERVATIONAL
• Study Start Date: 2023-02-28
• Study Completion Date: 2025-05-10

Brief Summary

General anesthesia is associated with loss of pulmonary functional residual capacity and the consequent development of atelectasis and closure of the small airway.

Mechanical ventilation in a lung with reduced functional residual capacity and atelectasis increased the dynamic alveolar stress-strain, inducing a local inflammatory response in atelectatic lung areas known as ventilatory-induced lung injury. This phenomenon may appear even in healthy patients undergoing general anesthesia and predisposes them to hypoxemic episodes that can persist in the early postoperative period.

Lung recruitment maneuvers restore the functional residual capacity and, therefore, protect the lungs from lung injury. A key issue in this kind of treatment is detecting the lung's closing pressure in order to maintain the end-expiratory pressure above such a limit.

Detailed Description

This is a prospective and observational study designed to measure the lung's closing pressure. The investigators will study 20 mechanically ventilated patients scheduled for mediastinoscopy surgery under general anesthesia.

Lung mechanics and capnography will be assessed during surgery. A slow pressure-volume curve will be automatically performed by the ventilator, and the small airway closing pressure will be determined as the inflection point in the alveolar slope of the pressure-CO2 and volume-CO2 curves. Then, a lung recruitment maneuver will be applied following a descending positive end-expiratory pressure trial to determine the lung's closing pressure. The investigator will see if the lung's closing pressure found with these two techniques is similar.

Conditions

Atelectasis

Study Design

• Observational Model Type: COHORT
• Study Time Perspective: PROSPECTIVE

Study Groups

Adults anesthetized patients undergoing mediastinoscopy

Determination of the lung's closing pressure by pressure-CO2 and volume-CO2 curves using a slow pressure-volume curve after anesthesia induction. Later on, a standard lung recruitment maneuver followed by a positive end-expiratory pressure trial was done to detect the lung's closing pressure.

Slow pressure-volume curve

Intervention Type: DIAGNOSTIC_TEST

Patients will be sequentially subjected to a slow pressure-volume curve and a lung recruitment maneuver

Interventions

Slow pressure-volume curve

Patients will be sequentially subjected to a slow pressure-volume curve and a lung recruitment maneuver

Intervention Type: DIAGNOSTIC_TEST

Other Intervention Names

Lung recruitment maneuver

Eligibility Criteria

Inclusion Criteria

• Age > 17 years ole
• Programmed surgery

Exclusion Criteria

• Pregnancy
• No programmed surgery
• Hemodynamic instability
• Severe COPD
• Acute respiratory infection

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 70 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Hospital Privado de Comunidad de Mar del Plata

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Nora Fuentes, PhD

Role: STUDY_CHAIR

Hospital Privado de Comunidad

Locations

Hospital Privado de Comunidad

Mar del Plata, Buenos Aires, Argentina

Countries

Argentina

Other Identifiers

CP2023

Identifier Type: -

Identifier Source: org_study_id