Evaluation of the relationship between airway measurements with ultrasonography and laryngoscopy in newborns and infants

Abstract

Background: A difficult laryngoscopy in young children can be a stressful situation for the pediatric anesthetist. In recent years, several measurements have been used to obtain difficult laryngoscopy markers in children. However, there is no prospective study in which ultrasonography is expected to be used for this purpose, particularly in the newborn and infant age groups. Goals: In this study, our goal was to evaluate the relationship between the preoperative airway assessment tools and the difficult laryngoscopic view in neonates and infants. Methods: Our study included newborns and infants undergoing elective surgery requiring intubation under general anesthesia. The following measurements were recorded the following: patients' age, body mass index, thyromental distance, mandibular length, the distance between the lip corner and ipsilateral ear tragus, and the transverse length (measured by hand with sign-middle-ring fingers side by side). In the thyromental distance measurement, the "thyroid notch" was determined by ultrasonography. Glottic structures appearing during laryngoscopy were graded according to the Cormack-Lehane Classification. Results: Of the 150 patients included in the study, 36 were female, and 92% were under the age of one. The incidence of difficult laryngoscopic views was 8% in the age groups studied, and the frequency of difficult laryngoscopic views in the newborn age group was 14.3%. The relationship between airway assessment tools and the Cormack-Lehane Classification scores was statistically significant. The negative predictive value was high for all values. Conclusions: The risk of a difficult laryngoscopy increases in children under the age of one. The preoperative airway assessment tools and body mass index had acceptable negative predictive values. We believe that all measurements could be used as markers for difficult laryngoscopy in newborns and infants.

Recommendations from the Brazilian Society of Anesthesiology (SBA) for difficult airway management in pediatric care

“… 17 In children between 0 and 2 years of age, an association is described between difficult laryngoscopy and body mass index (< 15.10 kg.m −2 ), thyromental distance (< 3.55 cm, a more specific parameter), mandibular length (< 6.5 cm), tragus to mouth distance (< 7.75 cm) and age less than 1 year. 18 In children under 5 years of age, the combined assessment of the lower lip-to-chin distance (< 2.2 cm), the tragus-to-mouth distance (< 3.9 cm), and low body mass index (< 12.17 kg.m −2 ) correlate with difficult glottis visualization during laryngoscopy, with high specificity and sensitivity. 15 …”

A Scoping Review of Ultrasonographic Techniques in the Evaluation of the Pediatric Airway

“…However, a combination of multiple ultrasound metrics and clinical examination can predict difficult laryngoscopy with greater accuracy than a single measurement alone 66 . Very few studies have evaluated difficult laryngoscopy using ultrasound in pediatric patients 69 …”

“…66 Very few studies have evaluated difficult laryngoscopy using ultrasound in pediatric patients. 69 Suprahyoid Soft Tissue Indices Technique The patient is supine with the neck extended. A linear, high-frequency probe with soft tissue or musculoskeletal preset is used to obtain the required images.…”

Point-of-Care Ultrasound in the Pediatric Intensive Care Unit

“…Ultrasound metrics evaluating anterior neck soft tissue thickness and mobility of the neck were found to be important predictors of a difficult laryngoscopy ( 96 ). To date, only one pediatric study evaluating ultrasound for difficult laryngoscopy has been performed that demonstrated good sensitivity (100%) and negative predictive value (100%) but with modest specificity (62%) and positive predictive value (19%) ( 97 ).…”