Video-Assisted Orotracheal Intubation in Rats Using a Low-Cost Smartphone-Connected Otoscope
July 14th, 2026
This protocol describes a simple, low-cost, video-assisted method for orotracheal intubation, enabling rapid and visually guided intubation in adult rats under isoflurane anesthesia.
Rats are widely used in experimental and translational research, particularly in surgery model requiring control and mechanical ventilation. Airway management in rats remain technically challenging due to the small and narrow cavity, glottic opening on anatomical angulation of the airway. Several intubation techniques have been described, including blind methods and video-assisted system.
While effective, these approaches often require operator expertise, specialized equipment, or device modification. In this video, we present a simple, low-cost, and reproducible method for orotracheal intubation in rats using a commercially available video otoscope under isoflurane anesthesia. The required equipment for this procedure includes an inclined intubation platform set at 45 degrees, which allows stable positioning during the procedure, a video otoscope with integrated light source and wireless display, a Velcro band, a flexible guide wire, and a suitable size endotracheal tube.
And finally, a small animal ventilator. Following intraperitoneal injection of xylazine 5 milligram per kilogram for anesthesia and subcutaneous buprenorphine 0.05 milligram per kilograms, animals were placed in an induction chamber with isoflurane for 15 minutes. Tighten the Velcro band around the intubation platform.
Then, slide the ventilation mask underneath the Velcro band to ensure oxygenation of the animal during the intubation procedure. Place the rat in the supine position on the 45-degree inclined intubation platform, then secure the upper incisors to stabilize head extension using the Velcro band. Confirm adequate anesthetic depth by verifying the absence of withdrawal reflexes in the forelimbs, hindlimbs, and tail in a response to natural stimulation.
Gently extend the tongue and introduce the video otoscope into the oral cavity. Press the tongue against the floor of the mouth and advance until the soft palate is rised. Apply gentle traction to expose the vocal cords.
Insert the flexible guide wire through the vocal cord and advance the endotracheal tube over the guide into the trachea until a characteristic tactile sensation corresponding to the tracheal rings is perceived. Remove the guide wire and connect the tube to the ventilator. After the intubation, confirm correct placement of the endotracheal tube by observing bilateral thoracic expansion, a stable capnography waveform, and adequate oxygen saturation.
Orotracheal intubation was successfully achieved in all 50 animals. The procedure duration was consistently under one minute, with a 100%first attempt success rate. Heart rate remains stable throughout the procedure.
Also, oxygen saturation remains stable throughout the procedure, with value consistently above 95%Capnography show regular waveforms, with end-tidal CO2 maintained between 50 and 60 millimeters of mercury. Tidal volume remains stable during mechanical ventilation. Microscopic examination of the trachea following extubation reveal no injuries.
Also, histological examination of the trachea following extubation reveal no visible epithelial damage attributable to intubation procedure. This protocol provide a simple and accessible approach for orotracheal intubation in a rat using a video otoscope without device modification. Continuous visualization reduce operator dependence and minimize the risk of oesophageal intubation.
The technique is particularly suitable for experimental model requiring control ventilation. One limitation of this method is the requirement for proper tongue positioning, which is critical for optimal visualization. Additionally, validation was performed in adult rats.
Adaptation may be necessary for small animal. Overall, this low-cost, minimally invasive technique represents a reliable method for rats airway management in experimental research.
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Overview
This article presents a simple, low-cost, and reproducible protocol for orotracheal intubation in rats using a commercially available video otoscope. The method enables real-time visualization of the upper airway, facilitating rapid and reliable intubation for experimental procedures requiring controlled ventilation, particularly in thoracic and cardiovascular research. The technique was successfully applied to a cohort of 50 adult rats, demonstrating high first-attempt success and minimal complications.
Key Study Components
Area of Science
- Experimental surgery
- Animal models
- Respiratory physiology
Background
- Rats are commonly used in experimental and translational research, especially for surgical models requiring mechanical ventilation.
- Airway management in rats is technically challenging due to small oral cavities and anatomical angulation.
- Existing intubation techniques often require specialized equipment, device modification, or significant operator expertise.
- Reliable intubation is critical to ensure controlled ventilation and minimize peri-procedural complications.
Purpose of Study
- To describe and validate a straightforward, cost-effective method for orotracheal intubation in rats.
- To utilize a video otoscope for continuous airway visualization during intubation.
- To assess the feasibility, safety, and reproducibility of this approach in a cohort of adult rats.
Methods Used
- Adult rats were anesthetized with xylazine and isoflurane, with buprenorphine for analgesia.
- Animals were positioned supine on a 45-degree inclined intubation platform and stabilized using a Velcro band.
- A video otoscope with integrated light and wireless display was used for real-time visualization of the airway.
- A flexible guide wire and endotracheal tube were inserted under direct vision; correct placement was confirmed by thoracic expansion, capnography, and oxygen saturation.
- Mechanical ventilation was initiated post-intubation, and tracheal integrity was assessed microscopically and histologically after extubation.
Main Results
- Orotracheal intubation was achieved in all 50 rats, with a 100% first-attempt success rate.
- The procedure duration was consistently under one minute.
- Physiological parameters (heart rate, oxygen saturation, end-tidal CO2, tidal volume) remained stable throughout.
- No tracheal injuries or epithelial damage were observed upon microscopic and histological examination.
Conclusions
- This video-assisted intubation protocol is simple, accessible, and minimizes the risk of esophageal intubation and airway trauma.
- Continuous visualization reduces operator dependence and enhances procedural safety.
- The method is particularly suitable for experimental models requiring controlled ventilation in adult rats, though adaptation may be needed for smaller animals.
Frequently Asked Questions
Executive Industry Relevance
Reliable airway management in small animal models is critical for translational research, especially in studies requiring controlled ventilation during thoracic or cardiovascular procedures. This video-assisted orotracheal intubation protocol for rats addresses technical barriers by enabling reproducible, real-time visualization without specialized equipment or device modification. The method supports consistent experimental conditions, reducing procedural variability and enhancing data integrity across preclinical studies.
Strategic Applications in Biopharma R&D
Early Discovery & Target Validation
- Enables robust physiological support for disease and intervention models requiring mechanical ventilation.
- Reduces procedural variability, supporting reproducible target validation in vivo.
- Minimizes operator dependence, lowering the risk of confounding variables in mechanistic studies.
Screening & Assay Development
- Facilitates preparation of standardized animal models for downstream pharmacological or surgical assays.
- Supports reproducible induction of controlled ventilation, critical for quantitative physiological measurements.
- Enables consistent model setup for comparative compound evaluation in respiratory or cardiovascular research.
Translational & Preclinical Research
- Improves continuity between discovery and preclinical validation by standardizing airway management protocols.
- Reduces peri-procedural complications, supporting risk-adjusted advancement of translational models.
- Enhances predictive confidence in preclinical endpoints by minimizing technical artifacts.
Pipeline & Workflow Integration
This protocol integrates into the preclinical workflow for studies requiring mechanical ventilation, bridging early discovery and translational research phases.
- Discovery Biology: Supports hypothesis testing in models where respiratory control is essential for outcome validity.
- Screening: Provides a reproducible platform for evaluating interventions under controlled ventilation conditions.
- Analytics: Enables quantitative monitoring of oxygen saturation, capnography, and physiological stability during procedures.
- Translational Research: Aligns with best practices for minimizing technical variability in animal models.
- Enterprise Reuse: Offers a scalable, low-cost airway management solution adaptable across research teams and studies.
Operational & Enterprise Impact
- Scientific Value: Increases predictive confidence and reduces mechanistic ambiguity in ventilated animal models.
- Operational Value: Standardizes airway management, improving reproducibility and scalability across studies.
- Strategic Value: Enables better go/no-go decisions by reducing technical failure rates and peri-procedural risk.
- Portfolio Impact: Supports risk-adjusted prioritization of translational models and experimental platforms.
Implementation Considerations
- Requires operator training in tongue positioning and airway visualization for optimal results.
- Needs access to a video otoscope with wireless display and compatible animal ventilator.
- Standardization across teams is facilitated by the protocol's reproducibility and minimal equipment requirements.
- Adaptation may be necessary for smaller animals or alternative species due to anatomical differences.
- Proper validation in the intended model system is essential before broad implementation.