Effect of Diluent Volume on Colistin Inhalation Therapy

Effect of Diluent Volume on Colistin Inhalation Therapy for Mechanically Ventilated Respiratory Patients

The aim of this study is to investigate the impact of different diluent volumes for the same dosage of colistin in mechanically ventilated respiratory patients receiving colistin inhalation therapy. The study aims to determine whether the diluent volume has an effect on clinical outcomes, including ICU length of stay, total hospitalization duration, duration of respiratory support within 28 days, mortality rates within 28 days and 90 days, as well as analyze the pharmacokinetic profile of colistin in blood and bronchoalveolar lavage fluid. Additionally, the study will evaluate the incidence of nebulizer malfunctions and blockages. The findings of this research will help identify the optimal diluent volume for colistin inhalation therapy in clinical practice.

Study Overview

• Status: Recruiting
• Conditions: Inhalation Pneumonia
• Intervention / Treatment: Other: Colistin 1 MU in normal saline 1 ml; Other: Colistin 1 MU in normal saline 2 ml

Detailed Description

Background： Colistin is an antibiotic used to treat infections caused by multidrug-resistant Gram-negative bacteria. In recent years, it has been widely utilized as an inhaled antibiotic for the treatment of respiratory infections in critically ill patients on mechanical ventilation. Despite the increasing use of colistin inhalation therapy for ventilator-associated pneumonia, the clinical impact of diluent volume on nebulization efficiency remains unclear.

Study Design： A single-center, prospective, randomized controlled trial.

Methods： The study plans to enroll 60 participants. Colistin inhalation therapy will be administered using a blocked stratified random allocation. The control group will receive colistin 6 MU diluted in 6 ml of normal saline (1 MU per 1 ml), while the experimental group will receive colistin 6 MU diluted in 12 ml of normal saline (1 MU per 2 ml). The dosage, frequency, and administration method of colistin inhalation will follow the clinical standard of 6 MU, administered every 8 hours, continuously for 7 days.

Effect： The investigators anticipate that the clinical outcomes and pharmacokinetics of colistin inhalation therapy will not differ significantly between different diluent volumes. Based on comprehensive evaluation, a diluent volume of 12 ml is considered more suitable than 6 ml for the dilution of colistin.

• Study Type: Interventional
• Enrollment (Estimated): 60
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Ke-Yun Chao, PhD; Phone Number: +886-905-301-879; Email: C00152@mail.fjuh.fju.edu.tw

Study Locations

• Taiwan
  • New Taipei City, Taiwan, 24352
    • Recruiting
    • Fu Jen Catholic University Hospital, Fu Jen Catholic University
    • Contact: Ke-Yun Chao, PhD; Phone Number: +886-905-301-879; Email: ck_qq@hotmail.com
    • Principal Investigator: Ke-Yun Chao, PhD

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Admitted to the Intensive Care Unit.
• Age greater than 18 years and using a ventilator due to acute respiratory failure.
• Requires inhalation colistin treatment as determined by the disease.
• Sign the written informed consent form.

Exclusion Criteria:

• Renal failure requiring renal dialysis.
• Receiving both inhaled colistin and intravenous colistin treatments.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Colistin 1 MU in normal saline 1 ml; 1 MU of colistin in a total volume of 6 ml, diluted with a 1:1 ratio in normal saline (0.9%)	Other: Colistin 1 MU in normal saline 1 ml; Colistin 1 MU diluted in normal saline 1 ml, total volume of 12 ml
Experimental: Colistin 1 MU in normal saline 2 ml; 1 MU of colistin in a total volume of 12 ml, diluted with a 1:2 ratio in normal saline (0.9%)	Other: Colistin 1 MU in normal saline 2 ml; Colistin 1 MU diluted in normal saline 2 ml, total volume of 12 ml

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Drug concentration	Drug concentration in bronchoalveolar lavage fluid and blood	One hour post inhalation therapy with colistin on the third day of treatment

Collaborators and Investigators

• Sponsor: Fu Jen Catholic University
• Investigators: Principal Investigator: Ke-Yun Chao, PhD, Fu Jen Catholic University Hospital

Study record dates

Study Major Dates

• Study Start (Actual): March 10, 2024
• Primary Completion (Estimated): July 31, 2026
• Study Completion (Estimated): July 31, 2026

Study Registration Dates

• First Submitted: January 21, 2024
• First Submitted That Met QC Criteria: January 21, 2024
• First Posted (Actual): January 30, 2024

Study Record Updates

• Last Update Posted (Actual): February 27, 2026
• Last Update Submitted That Met QC Criteria: February 25, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Keywords: randomized controlled trial; antibiotic; inhalation therapy; Colistin; diluent volume
• Additional Relevant MeSH Terms: Respiratory Tract Infections; Infections; Respiratory Tract Diseases; Lung Diseases; Pneumonia; Pneumonia, Aspiration; Pharmaceutical Preparations; Crystalloid Solutions; Isotonic Solutions; Solutions; Saline Solution
• Other Study ID Numbers: FJUH112294

Drug and device information, study documents

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