Evaluation of the Impact of 7% Sodium Chloride Nebulization on Lung Function and Quality of Life in Chemical War Veterans

Effect of 7% Sodium Chloride Administered via Mesh Nebulizer on Pulmonary Function and Quality of Life in Chemical Warfare Veterans

A double-blind, parallel-group, stratified block-randomized, phase 2-3 controlled clinical trial on 62 chemical warfare veterans

The study will be conducted as a double-blind, randomized clinical trial in the specialized pulmonary clinic of Baqiyatallah Hospital in Tehran. After initial screening and eligibility verification by a pulmonary specialist, participants will be randomly assigned to two intervention and control groups. Clinical assessments and pulmonary function tests will be performed at weeks 0, 4, and 8, and data will be collected and analyzed by an independent team without knowledge of the type of intervention.

Inclusion criteria: age between 40 and 70 years, medical confirmation of lung complications due to mustard gas, absence of acute respiratory infection in the past 4 weeks, and no changes in baseline medications in the past month. Exclusion criteria: unrelated respiratory diseases, heart or Renal failure, and smoking/alcohol consumption in the past 6 months.

the intervention group, which will receive a 7% NaCl solution twice daily for 8 weeks, and the control group, which will receive a 0.9% normal saline solution according to the same protocol. Both solutions are manufactured by Saha Daru Company.

Forced expiratory volume in the first second, forced vital capacity, peak expiratory flow, total score of the Respiratory Disease Quality of Life Questionnaire, frequency of cough episodes, volume of sputum production, dyspnea, and C-reactive protein level.

In this study, block randomization with a block size of 4 will be used to allocate participants into two groups: the intervention group (receiving 7% NaCl via mesh nebulizer) and the control group (receiving normal saline). Randomization will be performed at the individual level, with stratification based on the severity of pulmonary disease (moderate/severe). The random sequence will be generated using R software and placed in sealed envelopes to ensure proper allocation concealment. An independent colleague will be responsible for managing the envelopes, and both patients and researchers will remain blinded to group assignments until the intervention begins (double-blind). This method prevents imbalance between groups and has been designed in accordance with CONSORT standards for randomized clinical trials.

In this study, a strict double-blinding system is designed in which both patients and investigators will be unaware of the type of treatment they will receive. Patients will be treated without knowing the actual content of the nebulized solutions (7% NaCl or normal saline), while the treating physicians, nurses, outcome assessors, and data collection team will also be unaware of the group allocation of patients. Drug solutions will be prepared and delivered by the project pharmacist in completely identical containers without special markings. Statistical analysts will also not be aware of the grouping codes until the end of the primary analysis phase. Only the safety and data monitoring committee will have access to the actual data to monitor the safety of the study.