Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2020 May 1;318(5):L1032-L1035.
doi: 10.1152/ajplung.00498.2019. Epub 2020 Apr 1.

Video laryngoscopic oral intubation in rats: a simple and effective method

Claudius Balzer  1 , William J Cleveland  1 , Tulasi R Jinka  2   3 , Matthias L Riess  4   1   5
Affiliations

Video laryngoscopic oral intubation in rats: a simple and effective method

Claudius Balzer et al. Am J Physiol Lung Cell Mol Physiol. .

Abstract

Endotracheal intubation is a vital component of many rat in vivo experiments to secure the airway and allow controlled ventilation. Even in the hands of experienced researchers, however, the procedure remains technically challenging. The safest and most reliable way for human intubation is by video laryngoscopy. Previous attempts to apply this technique in rodents have been complicated and expensive. We, hereby, describe a novel, noninvasive method to safely intubate rats orally by video laryngoscopy, thus avoiding the need for a surgical tracheostomy. By repurposing a commercially available ear wax removal device, visualization of the rat larynx can be significantly enhanced. Because of its small diameter, integrated illumination, and a powerful camera with adequate focal length, the device has all of the necessary properties for exploring the upper airway of a rat. After identifying the vocal cords by video laryngoscopy, the insertion of an endotracheal tube (a 14G intravenous catheter) into the trachea under constant visual control is facilitated by using PE50 polyethylene tubing as a stylet (Seldinger technique). The procedure has been performed more than 60 times in our laboratory; all intubations were successful on the first attempt, and no adverse events were observed. We conclude that the described procedure is a simple and effective way to intubate a rat noninvasively, using inexpensive and commercially available equipment.

Keywords: endotracheal intubation; in vivo; mechanical ventilation; respiratory physiology; rodents.

PubMed Disclaimer

Conflict of interest statement

No conflicts of interest, financial or otherwise, are declared by the authors.

Figures

Fig. 1.
Fig. 1.
Positioning and equipment for video laryngoscopy and intubation of rats. A fast and secure fixation of the rat is performed by loose tape inferior to the upper incisors locked with LEGO bricks on a modified LEGO base plate (A). The anesthetized rat on the board is positioned on the bench at a 45° angle head up (B). The blade is attached to the camera at the upper field of view (C). A stylet (15 cm PE50 polyethylene tubing; Instech Laboratories, Plymouth Meeting, PA) is inserted into a 14 gauge intravenous catheter (Smith Medical ASD, Southington, CT) and advanced 1–2 cm past the catheter tip (D).
Fig. 2.
Fig. 2.
Insertion of the video laryngoscope (VL) and field of view during intubation. The VL is introduced into the mouth of the rat with the blade gliding along the tongue (A). The tip of the blade is carefully placed next to the epiglottic valleculae (B). The epiglottis is raised with a slight move of the tip of the blade in ventral direction (C). The stylet is inserted into the glottis (D). Once the stylet has passed the glottis ~1 cm (E), the endotracheal tube (ET) is passed over the stylet into the trachea (F), and finally the stylet is pulled back. The procedure can also be watched in Supplemental Video S1 available at www.doi.org/10.6084/m9.figshare.11891571.v2.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

References

    1. Andreatta RD, Stemple JC, Seward TS, McMullen CA. Subcutaneous neurotrophin 4 infusion using osmotic pumps or direct muscular injection enhances aging rat laryngeal muscles. J Vis Exp (124): 13, 2017. doi:10.3791/55837. - DOI - PMC - PubMed
    1. Ayala P, Torres J, Vivar R, Olmos PR, Meneses M, Borzone GR. Changes in the pattern of fibrosis in the rat lung with repetitive orotracheal instillations of gastric contents: evidence of persistent collagen accumulation. Am J Physiol Lung Cell Mol Physiol 315: L390–L403, 2018. doi:10.1152/ajplung.00559.2017. - DOI - PubMed
    1. Aziz MF, Dillman D, Fu R, Brambrink AM. Comparative effectiveness of the C-MAC video laryngoscope versus direct laryngoscopy in the setting of the predicted difficult airway. Anesthesiology 116: 629–636, 2012. doi:10.1097/ALN.0b013e318246ea34. - DOI - PubMed
    1. Carvajal Monroy PL, Grefte S, Kuijpers-Jagtman AM, Helmich MPAC, Ulrich DJO, Von den Hoff JW, Wagener FADTG. A rat model for muscle regeneration in the soft palate. PLoS One 8: e59193–e59198, 2013. doi:10.1371/journal.pone.0059193. - DOI - PMC - PubMed
    1. Cheong SH, Lee KM, Yang YI, Seo JY, Choi MY, Yoon YC. Blind oral endotracheal intubation of rats using a ventilator to verify correct placement. Lab Anim 44: 278–280, 2010. doi:10.1258/la.2010.009118. - DOI - PubMed

Publication types

LinkOut - more resources

-