Pleural Effusion Types in Chronic Kidney Disease

NCT07547852 | Not Yet Recruiting

• 1 other identifier: Pleural Effusion Types in CKD
• Study Type: observational
• Target: 100
• Locations: 0 countries
• Sites: N/A

Brief Summary

The purpose of this observational study is to understand the causes of pleural effusion (a buildup of fluid around the lungs) in patients with advanced Chronic Kidney Disease (CKD Stages 3 to 5). Pleural effusion is a common complication in kidney disease, but it can be caused by many different issues, such as simple fluid overload, heart failure, or infections like tuberculosis. To treat this fluid buildup effectively, doctors need to classify whether the fluid is a transudate (usually caused by pressure imbalances like fluid overload) or an exudate (caused by inflammation, lung disease, or infection). Standard medical formulas, known as Light's Criteria, are typically used to figure this out by comparing proteins in the fluid to proteins in the blood. However, these standard tests may sometimes misclassify the fluid in kidney disease patients because their baseline blood protein and albumin levels are often altered by their condition. Researchers in this study will enroll adult CKD patients (both on dialysis and not yet on dialysis) who have confirmed fluid around their lungs. Participants will undergo a standard, ultrasound-guided procedure called a diagnostic thoracentesis to safely draw a small amount of the chest fluid. At the same time, a routine blood sample will be taken. The study aims to:

• Compare the chest fluid to the blood sample using standard criteria, abbreviated criteria, and the Serum-Pleural Effusion Albumin Gradient (SPAG).
• Determine the most common underlying causes of lung fluid across different stages of kidney disease.
• Identify which diagnostic formula is the most accurate for CKD patients, helping doctors avoid misdiagnosis and provide better, more targeted treatments.

Conditions

Pleural Effusion; Chronic Kidney Disease

Keywords

Light's Criteria; Serum-Pleural Effusion Albumin Gradient (SPAG); Transudate; Exudate; Thoracentesis; Uremic Pleuritis; Hemodialysis

Outcome Measures

Primary Outcomes (1)

• Number of Participants Classified with Transudative or Exudative Pleural Effusions

  The primary outcome assesses the number of participants whose pleural effusion is classified as either transudative or exudative. This classification is determined by applying Standard Light's Criteria to pleural fluid and simultaneous serum laboratory tests. An effusion is defined as exudative if any one of the following is met: pleural fluid/serum protein ratio \> 0.5 , pleural fluid/serum LDH ratio \> 0.6 , or pleural fluid LDH \> 2/3 of the upper normal limit of serum LDH. If none are met, it is classified as transudative.

  Baseline (at the time of diagnostic thoracentesis)

Study Arms (1)

CKD Stage 3-5 with Pleural Effusion

Adult patients (≥18 years old) with a confirmed diagnosis of Chronic Kidney Disease (CKD) Stages 3 through 5, including both pre-dialysis and dialysis-dependent patients, who present with a radiologically confirmed pleural effusion. Patients in this cohort will undergo an ultrasound-guided diagnostic thoracentesis alongside simultaneous serum laboratory testing. The collected pleural fluid and serum will be analyzed to classify the effusion (using Light's Criteria, abbreviated criteria, and SPAG) and to determine its underlying etiology.

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

The study population comprises adult patients (≥18 years) with a confirmed diagnosis of Chronic Kidney Disease (CKD) Stages 3, 4, or 5 (eGFR \< 60 mL/min/1.73 m² for ≥3 months) who present with a radiologically confirmed pleural effusion. The cohort includes both pre-dialysis patients and those currently on maintenance hemodialysis or peritoneal dialysis. Participants will be enrolled from Assiut University Hospitals. Patients with acute kidney injury, trauma-related effusions, active malignancies, post-surgical effusions, or those who are pregnant are excluded from the sample.

You may qualify if:

• Adults aged ≥18 years of either sex
• Confirmed diagnosis of CKD Stage 3-5 based on eGFR \< 60 mL/min/1.73 m² for ≥3 months, as per KDIGO 2012 guidelines
• Radiologically confirmed pleural effusion on chest X-ray (CXR) or thoracic ultrasound
• Patients on hemodialysis or peritoneal dialysis, as well as those not yet on dialysis (CKD Stage 3-5 pre-dialysis)
• Willingness to provide written informed consent

You may not qualify if:

• Patients with Acute Kidney Injury (AKI) or acute-on-chronic kidney disease without prior CKD diagnosis
• Trauma-related pleural effusion (hemothorax, chylothorax)
• Known active malignancy with suspected malignant effusion
• Patients with post-surgical or iatrogenic pleural effusion
• Patients who refuse consent or are unable to undergo thoracentesis due to coagulopathy or other contraindications
• Pregnancy

Sponsors & Collaborators

• Assiut University: lead

MeSH Terms

Conditions

Pleural Effusion; Renal Insufficiency, Chronic

Condition Hierarchy (Ancestors)

Pleural Diseases; Respiratory Tract Diseases; Renal Insufficiency; Kidney Diseases; Urologic Diseases; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Urogenital Diseases; Male Urogenital Diseases; Chronic Disease; Disease Attributes; Pathologic Processes; Pathological Conditions, Signs and Symptoms

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Resident at Chest Diseases Department, Assiut University

Study Record Dates

• First Submitted: April 17, 2026
• First Posted: April 23, 2026
• Study Start: May 1, 2026
• Primary Completion (Estimated): May 1, 2027
• Study Completion (Estimated): June 1, 2027
• Last Updated: April 23, 2026

Record last verified: 2026-04