Effectiveness of Enzyme Spray Intervention on Thirst Relief in Patients With Endotracheal Intubation.

Summary

This study addresses the high prevalence (66%-70%) of thirst among intensive care unit (ICU) patients with endotracheal intubation, a symptom associated with oral mucosal dryness, nil per os (NPO) status, high-flow oxygen therapy, and medication effects. Unrelieved thirst may contribute to anxiety, delirium, and unplanned extubation. Current clinical practices, such as cold water or saline sprays, provide only transient relief and may pose aspiration risks. Enzyme-based saliva substitutes, which mimic natural saliva and stabilize the oral environment, show potential benefits; however, evidence in ICU populations remains limited.

A single-blind randomized controlled trial (RCT) will be conducted in an ICU of a medical center in southern Taiwan. Eligible participants are adult patients (≥18 years) with endotracheal intubation expected to exceed 24 hours, a baseline thirst intensity score (NRS-I) ≥3, and the ability to communicate. A total of 76 participants will be recruited and randomly assigned in a 1:1 ratio to either the experimental group (enzyme-based oral spray) or the control group (distilled water spray), using sequentially numbered, opaque, sealed envelopes (SNOSE) to ensure allocation concealment.

The intervention will be administered following routine oral care within a standardized time window (13:00-15:00). Both solutions will be prepared in identical opaque spray bottles to maintain blinding. The protocol includes 12 sprays per session (approximately 1.56 mL), delivered to four standardized intraoral sites, with outcomes monitored over a 4-hour period.

Primary outcomes include thirst intensity (Numerical Rating Scale-Intensity, NRS-I) and thirst distress (Numerical Rating Scale-Distress, NRS-D), assessed at baseline (T0) and at 30, 60, 120, and 240 minutes post-intervention (T1-T4) by blinded outcome assessors. No biological specimens will be collected; data will be obtained from self-reported measures and electronic medical records, with strict de-identification and secure storage procedures.

This study is considered minimal risk. Any adverse events, such as discomfort or choking, will result in immediate discontinuation of the intervention. Data will be analyzed using generalized estimating equations (GEE) to evaluate group, time, and interaction effects. The findings are expected to provide evidence-based guidance for improving thirst management, enhancing patient comfort, and optimizing the quality of critical care nursing.

Conditions

• Thirst

Interventions

OTHER

Enzyme-based oral spray (Oral7®)

An enzyme-based saliva substitute containing bioactive components such as lysozyme and lactoperoxidase, designed to mimic natural saliva, enhance oral moisture retention, and stabilize the oral microenvironment.

OTHER

Distilled water oral spray

Distilled water administered via oral spray to provide moisture to the oral cavity, serving as a comparator for the enzyme-based oral spray.

Sponsors & Collaborators

• Yeh,Shiao Feng

  lead OTHER

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

DOUBLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2026-04-10

Primary Completion

2026-09-30

Completion

2026-12-30

Countries

• Taiwan

Study Locations