McGRATH MAC video laryngoscope assistance during transesophageal echocardiography may reduce the risk of complications: a manikin study

Abstract

Background: Although transesophageal echocardiography (TEE) is considered a relatively safe diagnostic monitoring method, blind probe insertion is associated with pharyngeal trauma. Through visual observation of the esophageal inlet with the McGRATH video laryngoscope, it may be possible to insert the TEE probe at an appropriate angle and prevent pharyngeal trauma. We conducted a manikin study to investigate whether the use of the McGRATH video laryngoscope for TEE probe insertion reduced the pressure on the posterior pharyngeal wall.

Methods: Twenty-seven junior (inexperienced group) and 10 senior (experienced group) anesthesiologists participated in this study. The TEE probe was inserted into an airway manikin in a blind fashion (blind group) or under visualization with the McGRATH (McGRATH group) video laryngoscope (three times each). A sealed bag filled with normal saline was placed on the back of the posterior pharyngeal wall of the manikin and connected to a patient monitoring system via a pressure transducer. We measured the internal bag pressure and approximated this value to the pressure on the posterior pharyngeal wall.

Results: The pressure on the posterior pharyngeal wall was significantly lower in the McGRATH group than in the blind group (p < 0.001) and was significantly reduced when the McGRATH was employed in both the inexperienced (p < 0.001) and experienced (p < 0.001) groups.

Conclusions: These findings suggest that TEE probe insertion under the assistance of the McGRATH video laryngoscope can reduce the pressure on the posterior pharyngeal wall, regardless of the clinician's experience, and may inform clinical practice with the potential to reduce probe insertion-associated complication rates.

Keywords: McGRATH video laryngoscope; Probe insertion; Transesophageal echocardiography.

Conflict of interest statement

The authors declare that they have no competing interests.

Figures

Fig. 1

A sealed bag of normal saline on the back of the manikin’s posterior pharyngeal wall. (a) Location of the sealed bag. (b) A neonatal, soft, disposable blood pressure cuff filled with normal saline connected to a patient monitoring system via a pressure transducer

Fig. 2

The angle θ corresponds to the insertion angle of the TEE probe. The angle θ is defined as that between the TEE probe and the lip-nose tip line (yellow line) when the probe passes through the lips. TEE, transthoracic echocardiography