Lung Ultrasound to Assess Aeration Loss After Lung Resection Surgery (THORUS)

Lung Ultrasound Assessment of Aeration Changes After Lung Resection Surgery: A Pilot Study

The purpose of this prospective observational study is to assess perioperative changes in lung aeration after lung resection surgery using lung ultrasound, and to explore their relationship with oxygenation, inflammatory biomarkers, cardiac stress markers and diaphragmatic function.

Study Overview

• Status: Completed
• Conditions: Lung Cancer; Thoracic Surgery; Lung Neoplasm; Lung Ultrasound; Lung Ultrasound Score; One-lung Ventilation (OLV); Postoperative Pulmonary Complications (PPCs); Lung Resection Surgery
• Intervention / Treatment: Diagnostic test: Perioperative lung ultrasound assessment

Detailed Description

Postoperative pulmonary complications are common after lung resection surgery and are associated with worse clinical outcomes. Lung ultrasound (LUS) is a bedside, non-invasive and repeatable imaging technique that can detect regional changes in lung aeration. These changes may reflect postoperative loss of aeration related to one-lung ventilation, surgical manipulation, lung collapse and re-expansion, inflammatory response, diaphragmatic dysfunction or other perioperative mechanisms.

This is a prospective, single-centre, observational pilot study including consecutive adult patients scheduled for elective lung resection surgery under one-lung ventilation. Lung ultrasound was performed at three predefined time points: before surgery (T1), 30 minutes after extubation (T2), and 24 hours after surgery (T3). Each hemithorax was divided into six regions: anterior, lateral and posterior areas, each subdivided into upper and lower zones. For each examination, the most pathological ultrasound finding in each area was recorded. A semiquantitative lung ultrasound score was calculated to assess lung aeration over time, both globally and separately for the operated and non-operated lung. Corrected LUSS values were used to compensate for the loss of areas after surgery.

At the same predefined time points, oxygenation, NT-proBNP and plasma inflammatory biomarkers, including IL-6, IL-10 and TNF-α, were assessed. Bedside transthoracic echocardiography and diaphragmatic ultrasound were also performed as exploratory analyses to evaluate possible cardiovascular and diaphragmatic mechanisms associated with postoperative loss of lung aeration.

The primary objective of the study is to assess perioperative changes in lung aeration after lung resection surgery using LUS. Secondary objectives are to describe the regional distribution of LUS findings, compare the operated and non-operated lung, assess the feasibility of repeated perioperative LUS examinations, and explore the relationship between LUS changes and oxygenation, inflammatory biomarkers, cardiac stress markers and diaphragmatic function.

• Study Type: Observational
• Enrollment (Actual): 32

Contacts and Locations

Study Locations

• Spain
  • Valencia
    • Valencia, Valencia, Spain, 46014
      • Hospital General Universitario de Valencia

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Patients scheduled for elective lung resection surgery at a tertiary referral hospital.

Description

Inclusion Criteria:

• Age > 18
• ASA I-III
• Non-small cell lung neoplasm
• Elective lobectomy
• Under one-lung ventilation

Exclusion Criteria:

• pregnancy
• Diagnosed pulmonary fibrosis
• Scheduled surgery limited to biopsy
• Surgery that includes resection of the thoracic wall or the diaphragm
• Predicted FEV1 < 40%
• Neoplasm metastasis
• Obesity class II or more (BMI ≥ 35 kg/m^2)
• Risk of malnutrition CONUT score > 1
• Hemoglobin < 10 g/dl
• Chronic kidney failure: glomerular filtration < 60 ml/min/m^2, nephrectomy, kidney transplantation
• Treatment with corticosteroids or immunosuppressive agents 3 months before surgery
• Transfusion of blood products during the previous 10 days
• Heart failure (New York Heart Association Functional Class 3 or 4) during the week before surgery.
• Heart valve diseases over stage B of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines 2014
• Previously documented elevated left atrial pressure or cardiac disease associated with elevated left-sided filling pressures.

Study Plan

How is the study designed?

Design Details

• Observational Models: Cohort
• Time Perspectives: Prospective

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Lung resection surgery; Adult patients scheduled for elective lobectomy surgery under one-lung ventilation in a tertiary referral hospital.	Diagnostic test: Perioperative lung ultrasound assessment; Lung ultrasound was performed at three predefined perioperative time points: before surgery, in the immediate postoperative period after extubation, and 24 hours after surgery. Each hemithorax was assessed in six regions, and lung aeration was evaluated using a semiquantitative lung ultrasound score.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in lung aeration after lung resection surgery assessed by lung ultrasound score	The lung ultrasound score is a semiquantitative score used to assess lung aeration. Higher values indicate greater loss of aeration. Changes will be assessed between the preoperative period, the immediate postoperative period after extubation, and 24 hours after surgery.	preoperative vs immediate postoperative period vs 24 hours after surgery

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Regional distribution of lung ultrasound findings in the operated and non-operated lung	Description of lung ultrasound findings and lung aeration loss in each lung region at the predefined perioperative time points.	preoperative vs immediate postoperative period vs 24 hours after surgery
Changes in oxygenation after lung resection surgery	Oxygenation will be assessed using the PaO₂/FiO₂ ratio at the predefined perioperative time points.	preoperative vs immediate postoperative vs 24 hours after surgery
Changes in plasma inflammatory biomarkers after lung resection surgery	Plasma IL-6, IL-10 and TNF-α concentrations, and the IL-6/IL-10 ratio, will be assessed at the predefined perioperative time points.	preoperative vs immediate postoperative vs 24 hours after surgery
Changes in cardiac stress markers after lung resection surgery	NT-proBNP values will be assessed at the predefined perioperative time points and explored in relation to lung ultrasound findings.	preoperative vs immediate postoperative vs 24 hours after surgery
Changes in diaphragmatic function after lung resection surgery	Diaphragmatic function will be assessed by ultrasound using diaphragmatic thickening fraction at the predefined perioperative time points.	preoperative vs immediate postoperative vs 24 hours after surgery

Collaborators and Investigators

• Sponsor: Ana Broseta Lleó
• Collaborators: Hospital General Universitario de Valencia
• Investigators: Principal Investigator: Ana Broseta Lleó, Consultant, Hospital General Universitario de Valencia

Study record dates

Study Major Dates

• Study Start (Actual): December 20, 2020
• Primary Completion (Actual): January 30, 2022
• Study Completion (Actual): April 30, 2022

Study Registration Dates

• First Submitted: November 24, 2020
• First Submitted That Met QC Criteria: December 15, 2020
• First Posted (Actual): December 21, 2020

Study Record Updates

• Last Update Posted (Actual): June 18, 2026
• Last Update Submitted That Met QC Criteria: June 16, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Keywords: lung ultrasound; oxygenation; one-lung ventilation; thoracic surgery; cytokines; lung resection; lobectomy; NT-proBNP; postoperative pulmonary complications; lung ultrasound score; diaphragmatic function; lung aeration
• Additional Relevant MeSH Terms: Neoplasms by Site; Neoplasms; Respiratory Tract Diseases; Lung Diseases; Respiratory Tract Neoplasms; Thoracic Neoplasms; Lung Neoplasms
• Other Study ID Numbers: THORUS

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