[Orotracheal intubation difficulty with lighted stylet: correlation of body mass index and neck circumference].

OBJECTIVES

To evaluate the difficulty of intubation with a lighted stylet by correlating the body mass index (BMI) with the neck or cervical circumference (CC), and to establish the values of BMI and CC that could help identify a possible difficult intubation with this device.

PATIENTS AND METHODS

An observational and correlational study was performed on selected patients by consecutive sampling who were intubated using the lighted stylet. Variables such as age, gender, ASA physical status, BMI, CC, transillumination intensity, Cormack-Lehane grade, and Mallampati scores, were recorded. Multivariable analyses were performed.

RESULTS

103 patients were included. The mean age of the patients was 39.0 ± 16.6 years, BMI 28.6 ± 6.8 kg/m² (33% obese and 29,1% overweight), CC 37.8 ± 4.6 cm. Those patients who presented difficulty for intubation had a CC 39.9 ± 5.2 cm (P ≤ 0.05), and a BMI 33.8 ± 7.6 kg/m² (P = 0.01).

CONCLUSION

A lineal correlation exists between a BMI above 33 kg/m² and/or a CC greater than 40 cm and a difficult intubation using lighted stylet. Another method other than transillumination is recommended for orotracheal intubation in a patient with both characteristics.