Teoría de las dos curvas en el manejo de la vía aérea, desafiando la teoria de los tres ejes

The Three Axes Theory (TAT), described in the 1940s, aimed to explain the advantages of the sniffing position to achieve better ventilation conditions, greater visibility during direct laryngoscopy, and consequently, optimize intubation conditions.This theory was quickly accepted by the medical community, despite being based on limited evidence and relying on a habitual practice that neither systematizes the sniffing position nor quantifies axis alignment.In the early 2000s, the literature began to question the validity of the TAT, presenting evidence suggesting that these axes not only did not align in the sniffing position but, on the contrary, became misaligned.In this context, the question arises: if the TAT does not explain why maneuvers that elevate the head above the neutral position improve visibility during laryngoscopy, what explains the success of our maneuvers?The Two Curves Theory, developed by K. Greenland and colleagues, offers a plausible explanation that could account for the success of intubation with various devices.To date, this theory has gained acceptance and popularity; however, further work is needed to deepen its application in airway assessment, device selection, and execution of maneuvers for intubation.This work presents a literature review to explain the Two Curves Theory, its impact, and current applications.