Using a breathing index and a blood-based CALLY score to predict ventilator 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

This project will try to see if combining a breathing measure (RSBI) with a blood-based CALLY index helps predict which adult ICU patients can be taken off a ventilator and stay off it.

Quick facts

• Study type: Observational
• Enrollment: 105 (estimated)
• Ages: 18 Years and up
• Sex: All
• Sponsor: Istanbul University - Cerrahpasa (Academic / other)
• Locations: 1 site (Istanbul, Istanbul)
• Trial ID: NCT07571317 on ClinicalTrials.gov

What this trial studies

This is a prospective observational study of about 105 adult ICU patients who have been on invasive mechanical ventilation for at least 24 hours and are judged ready for a spontaneous breathing trial. Researchers will record the Rapid Shallow Breathing Index (RSBI) during weaning and calculate the CALLY index from CRP, albumin, and lymphocyte count to capture immuno‑nutritional and inflammatory status. Clinical severity scores, real-time respiratory parameters, and routine labs will be retrieved from the hospital information system and linked to weaning outcomes at 48 hours and 7 days after extubation. The goal is to determine whether combining RSBI with the CALLY index improves prediction of immediate and late extubation failure compared with physiological measures alone.

Who should consider this trial

Good fit: Adults (18+) in the ICU who have received invasive mechanical ventilation for at least 24 hours and are deemed ready for a spontaneous breathing trial with hemodynamic stability and acceptable cough/secretions.

Not a fit: Patients with active malignancy, neuromuscular diseases that impair respiratory effort, pregnancy, or those not undergoing an SBT (including some noninvasively ventilated patients) are unlikely to benefit from this prediction model.

Why it matters

Potential benefit: If successful, the combined measure could better identify patients likely to remain off the ventilator and reduce unplanned re‑intubations.

How similar studies have performed: RSBI is a long‑used but imperfect predictor of weaning outcome, and while immuno‑nutritional or inflammatory markers have been associated with outcomes, combining RSBI with the CALLY index is a relatively new approach with limited prior validation.

Eligibility criteria

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).

Where this trial is running

Istanbul, Istanbul

• Basaksehir Cam and Sakura City Hospital — Istanbul, Istanbul, Turkey (Türkiye) (Recruiting)

Study contacts

• Study coordinator: mahmut baran kasisari, medical doctor

Conditions Critical Illness; Respiratory Insufficiency; Ventilator Weaning; Weaning Failure of Mechanical Ventilation; mechanical ventilation; ventilator weaning; Systemic Inflammation; CRP-Albumin-Lymphocyte Ratio