Prognostic Significance of Pulmonary Function Tests in Adolescent İdiopathic Scoliosis Surgery

The Role of Preoperative Pulmonary Function Tests in Predicting Postoperative Intensive Care Need in Adolescent Idiopathic Scoliosis Surgery: A Retrospective Cohort Study

Adolescent idiopathic scoliosis (AIS) is a three-dimensional structural deformity of the spine, the etiology of which is not clearly known, and can be seen from the age of 10 until the skeletal system matures. The Scoliosis Research Society (SRS) defines AIS as vertebral rotation and a Cobb angle of 10° or greater. Its incidence varies between 0.47% and 5.2%. It is more common in women than in men. In patients with a Cobb angle greater than 40° or who are not yet bone-mature and who are continuously progressing, surgical intervention is often performed with posterior spinal fusion. Scoliosis negatively affects not only the appearance of patients but also their lung functions through differentiation in thoracic morphology and progression of spinal curvature. The severity of this restrictive pattern in lung functions can be assessed with pulmonary function tests (PFT). However, this test requires patient cooperation and is particularly difficult to perform in patients with cognitive dysfunction. Despite studies recommending the use of pulmonary function tests in preoperative risk assessment, the literature shows inconsistency in predicting the need for postoperative intubation and mechanical ventilation.

In this study, the effect of preoperative pulmonary function tests (PFT) performed before AIS surgery on the need for intensive care admission will be evaluated. In addition, the potential relationships between PFT results and intraoperative and postoperative blood transfusion needs, postoperative intubation needs, hospital stay, mortality status, inotropic support needs, Cobb angle, scoliosis location, and the number of affected vertebrae will be investigated.

Study Overview

• Status: Completed
• Conditions: Anesthesia; Adolescent Idiopathic Scoliosis; Pulmonary Function Test, Preoperative
• Intervention / Treatment: Diagnostic test: Pulmonary function test

Detailed Description

After local ethics committee approval, patients' age, gender, weight, American Society of Anesthesiologists (ASA) physical status, additional diseases, localization of scoliosis, number of vertebrae affected, Cobb angle and presence of chronic lung disease will be recorded within the scope of demographic data.

Cobb angle or lateral spinal curvature will be measured and recorded on the spine radiograph closest to the date of surgery. In terms of preoperative respiratory function tests, the results performed closest to the date of surgery and accepted as successful according to American Thoracic Society standards will be analyzed. In this context, forced vital capacity (FVC) percentage of normal, forced expiratory volume in 1 second (FEV1) percentage of normal, and FEV1/FVC ratios will be recorded. In the presence of an obstructive or restrictive pattern, FEV1/FVC or FVC Z-scores will be examined and evaluated as normal, mild, moderate or severe in accordance with European Respiratory Society/American Thoracic Society (ERS/ATS) guidelines. The Z-score shows how much the individual's measured value deviates from the reference population determined according to factors such as ethnicity, gender, age, and height. A z-score greater than -1.645 is considered normal, a z-score between -1.645 and -2.5 is considered mild, a z-score between -2.5 and -4.0 is considered moderate, and a z-score below -4.0 is considered severe.

The recorded data will be evaluated by considering the need for intensive care admission, need for intraoperative and postoperative blood transfusion, need for postoperative intubation, length of hospital stay, mortality status, need for inotropic support, Cobb angle, location of scoliosis and number of affected vertebrae. Postoperative intubation status will be defined as patients brought to the ICU without extubation or re-intubated within 24 hours.

• Study Type: Observational
• Enrollment (Actual): 165

Contacts and Locations

Study Locations

• Turkey
  • Ankara, Çankaya
    • Ankara, Ankara, Çankaya, Turkey, 06800
      • Ankara Bilkent City Hospital

Participation Criteria

Eligibility Criteria

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

• Sampling Method: Probability Sample

Study Population

Patients between the ages of 10-18 who underwent posterior spinal fusion surgery under general anesthesia due to Adolescent Idiopathic Scoliosis (AIS) will be included in the study. Exclusion criteria were determined as ASA (American Society of Anesthesiologists) score of 4 and above, body mass index >35 kg/m², mental retardation, Need for Bilevel Positive Airway Pressure (BPAP) before surgery, patients who could not successfully complete preoperative respiratory function tests, presence of tracheostomy and revision surgeries.

Description

Inclusion Criteria:

• Age range 10-18
• Patients who underwent posterior spinal fusion surgery for Adolescent Idiopathic Scoliosis under general anesthesia

Exclusion Criteria:

• Body mass index >35 kg/m²
• ASA (American Society of Anesthesiologists) score of 4 and above
• Patients who have undergone revision surgery
• Patients with mental retardation
• Need for Bilevel Positive Airway Pressure (BPAP) before surgery
• Patients who could not successfully complete preoperative respiratory function tests
• Preoperative tracheostomy presence
• Patients with vertebral anomaly due to a secondary reason
• Patients with a diagnosed syndrome

Study Plan

How is the study designed?

Number of groups / cohorts

4

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
normal risk; z score is greater than -1.645	Diagnostic test: Pulmonary function test; Pulmonary function test results performed closest to the date of surgery and considered successful according to American Thoracic Society standards
Low risk; z score between -1.645 and -2.5	Diagnostic test: Pulmonary function test; Pulmonary function test results performed closest to the date of surgery and considered successful according to American Thoracic Society standards
Medium risk; z score between -2.5 and -4.0	Diagnostic test: Pulmonary function test; Pulmonary function test results performed closest to the date of surgery and considered successful according to American Thoracic Society standards
High risk; z score of less than -4.0	Diagnostic test: Pulmonary function test; Pulmonary function test results performed closest to the date of surgery and considered successful according to American Thoracic Society standards

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Need for intensive care admission	The primary outcome of the study was to evaluate the effect of preoperative lung function tests performed before adolescent idiopathic scoliosis surgery on the need for postoperative intensive care admission.	2019 - 2024

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Hospital stay	Investigation of the potential relationship between pulmonary function test results and hospital stay	2019 - 2024
Need for blood transfusion	Investigation of the potential relationship between pulmonary function test results and need for blood transfusion	2019 - 2024
Mortality status	Investigation of the potential relationship between pulmonary function test results and mortality status	2019 - 2024
İnotropic support requirement	Investigation of the potential relationship between pulmonary function test results and inotropic support requirement	2019 - 2024
Cobb angle	Investigation of the potential relationship between pulmonary function test results and cobb angle	2019 - 2024
Location of scoliosis and number of affected vertebrae	Investigation of the potential relationship between pulmonary function test results and location of scoliosis and number of affected vertebrae	2019 - 2024
Need for postoperative intubation	Investigation of the possible relationship between lung function test results and the need for postoperative intubation Postoperative intubation status was defined as patients brought to the ICU without extubation or reintubated within 24 hours.	2019 - 2024

Collaborators and Investigators

• Sponsor: Ankara City Hospital Bilkent

Study record dates

Study Major Dates

• Study Start (Actual): January 2, 2025
• Primary Completion (Actual): February 21, 2025
• Study Completion (Actual): May 30, 2025

Study Registration Dates

• First Submitted: December 24, 2024
• First Submitted That Met QC Criteria: January 2, 2025
• First Posted (Actual): January 3, 2025

Study Record Updates

• Last Update Posted (Actual): May 31, 2025
• Last Update Submitted That Met QC Criteria: May 30, 2025
• Last Verified: May 1, 2025

More Information

Terms related to this study

• Keywords: Adolescent Idiopathic Scoliosis; Preoperative Pulmonary Function Test
• Additional Relevant MeSH Terms: Bone Diseases; Musculoskeletal Diseases; Spinal Diseases; Spinal Curvatures; Scoliosis
• Other Study ID Numbers: AIS

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