Combined Predictive Value of RSBI and CALLY Index in Predicting Weaning Success in ICU Patients

Combined Predictive Value of Rapid Shallow Breathing Index (RSBI) and CRP-Albumin-Lymphocyte (CALLY) Indices in Predicting the Success of Weaning From Mechanical Ventilation in Intensive Care Patients: A Prospective Observational Study

The primary objective of this prospective observational study is to evaluate the effectiveness of combining the Rapid Shallow Breathing Index (RSBI) and CRP-Albumin-Lymphocyte (CALLY) index to predict weaning success in adult patients within the intensive care unit. While weaning from mechanical ventilation is a critical clinical step, existing physiological metrics like RSBI do not fully capture a patient's inflammatory or nutritional status. This research introduces the CALLY index calculated as the ratio of the patient's immuno-nutritional reserve (Albumin and Lymphocytes) to systemic inflammation (CRP) as a complementary metabolic marker. By tracking approximately 105 participants at Basaksehir Cam and Sakura City Hospital, the study monitors weaning success over both a 48 hour and a 7 day period to identify both immediate and late phase extubation failures. The ultimate goal is to provide a more holistic prediction model that potentially reduces re-intubation rates and improves clinical outcomes by accurately identifying the optimal time for ventilator removal.

Study Overview

• Status: Recruiting
• Conditions: Critical Illness; Respiratory Insufficiency; Ventilator Weaning; Weaning Failure of Mechanical Ventilation

Detailed Description

This prospective observational study aims to evaluate the combined predictive value of the Rapid Shallow Breathing Index (RSBI) and CRP-Albumin-Lymphocyte (CALLY) index in determining the success of weaning from mechanical ventilation in intensive care patients. While the RSBI focuses on physiological respiratory mechanics, the CALLY index serves as a non invasive biomarker reflecting the patient's immunonutritional and inflammatory status.

Data collection is deepened through systematic retrieval from the Hospital Information Management System. Researchers will record a wide range of parameters, including demographic data such as age, gender, and BMI alongside clinical severity scores including APACHE II, SOFA, and the Charlson Comorbidity Index. Real time respiratory profiling, including minute ventilation, tidal volume, and airway pressures, will be documented during the weaning process and the Spontaneous Breathing Trial (SBT).

Laboratory integration focuses on routine markers such as CRP, albumin, and lymphocyte counts to determine the patient's biological status at the time of the SBT. In this study, the CALLY Index is generalized as a ratio of the patient's immuno-nutritional reserve to systemic inflammation, calculated as: (Albumin x Lymphocyte Count) / CRP.

The primary outcome is defined as weaning success, characterized by the patient remaining free from invasive mechanical ventilation following extubation. To ensure a comprehensive evaluation of respiratory stability, this study extends the primary observation period to include both the initial 48 hour window and a 7 day follow-up. By incorporating the 7 day parameter, the researchers aim to capture both immediate and late-phase weaning failures, providing a more robust assessment of the combined indices' predictive power for long term extubation success. Secondary outcomes include 28 day mortality rates and total duration of intensive care stay.

• Study Type: Observational
• Enrollment (Estimated): 105

Contacts and Locations

• Study Contact: Name: mahmut baran kasisari, medical doctor; Phone Number: +905072225254; Email: barankasisari@hotmail.com
• Study Contact Backup: Name: tugba yesilyurt dogu, medical doctor; Phone Number: +905535150847; Email: tugbaayesilyurt@gmail.com

Study Locations

• Turkey (Türkiye)
  • Istanbul
    • Istanbul, Istanbul, Turkey (Türkiye), 34480
      • Recruiting
      • Basaksehir Cam and Sakura City Hospital
      • Contact: mahmut baran kasisari, Medical Doctor; Phone Number: 905072225254; Email: barankasisari@hotmail.com

Participation Criteria

Eligibility Criteria

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

• Sampling Method: Non-Probability Sample

Study Population

The study population consists of adult patients hospitalized in the General Intensive Care Units of Basaksehir Cam and Sakura City Hospital who have been receiving invasive mechanical ventilation for at least 24 hours. Participants are identified from patients who meet the clinical requirements for a Spontaneous Breathing Trial and are considered candidates for weaning by the attending intensivist. The population represents a diverse group of critically ill patients requiring prolonged respiratory support, excluding those with specific confounding factors such as pregnancy, malignancy, or primary neuromuscular disorders

Description

Inclusion Criteria:

• Patients aged 18 years and older
• Patients who have received invasive mechanical ventilation for at least 24 hours in the general intensive care unit.

Patients who meet standard clinical weaning criteria (e.g., hemodynamic stability with minimal or no vasopressor support, adequate cough reflex, absence of excessive airway secretions).

Patients deemed ready for a Spontaneous Breathing Trial by the attending physician.

Exclusion Criteria:

• Patients under the age of 18.
• Patients with a known or detected pregnancy.
• Patients with a diagnosis of malignancy.
• Patients with neuromuscular diseases that could impair respiratory effort or muscle strength assessments (e.g., Myasthenia Gravis, Amyotrophic Lateral Sclerosis, Guillain-Barré syndrome).

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort
Successful Weaning; Patients who maintain respiratory stability without reintubation, rescue ventilation, or death during both the initial 48 hours post-extubation and the 7-day follow-up period.
Failed Weaning; Patients who experience reintubation, need for rescue ventilation, or mortality either within the first 48 hours post-extubation or during the 7-day monitoring phase.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Composite Weaning Success and Respiratory Stability Rate	The proportion of patients who remain free from invasive mechanical ventilation following extubation. Success is defined as the absence of reintubation, need for rescue ventilation, or death within two stages: 1) Immediate weaning success within the first 48 hours postextubation, and 2) Sustained respiratory stability throughout a 7 day follow-up period to capture late-phase weaning failures.	Up to 7 days post-extubation

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
28-Day Mortality Rate	This measure calculates the total number of days a patient requires invasive mechanical ventilation support during their stay in the intensive care unit.	28 days post enrollment

Collaborators and Investigators

• Sponsor: Istanbul University - Cerrahpasa

Study record dates

Study Major Dates

• Study Start (Estimated): May 4, 2026
• Primary Completion (Estimated): June 30, 2026
• Study Completion (Estimated): July 31, 2026

Study Registration Dates

• First Submitted: April 29, 2026
• First Submitted That Met QC Criteria: April 29, 2026
• First Posted (Actual): May 6, 2026

Study Record Updates

• Last Update Posted (Actual): May 11, 2026
• Last Update Submitted That Met QC Criteria: May 6, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: mechanical ventilation; ventilator weaning; Systemic Inflammation; CRP-Albumin-Lymphocyte Ratio
• Additional Relevant MeSH Terms: Pathologic Processes; Disease Attributes; Respiratory Tract Diseases; Respiration Disorders; Pathological Conditions, Signs and Symptoms; Respiratory Insufficiency; Critical Illness
• Other Study ID Numbers: E-96317027-514.10-311839049; KAEK-11/15.04.2026.138 (Other Identifier: Ethics Committee Approval Number)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: To protect patient privacy and comply with institutional data protection policies and ethical approval constraints

Drug and device information, study documents

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