Usefulness and diagnostic value of the NEMA parameter combined with other selected bedside tests for prediction of difficult intubation

Abstract

Study objective: To assess the usefulness of the new NEMA (Neck Circumference Minus Acromion-Acromion Distance) parameter, in preoperative identification of patients' difficult intubation and compare it with other commonly used scales and tests.

Design: Prospective study.

Setting: District Specialist Hospital of Lublin, Poland.

Patients: Six hundreds twenty-nine patients underwent nonemergency surgical interventions.

Measurements: The NEMA parameter was confronted with: Modified Mallampati classification, TMD, RHTMD, NC, MPND, SMD, I-I D, A-AD, and medical history of difficult intubation and diagnosed obstructive sleep apnea syndrome or snoring.

Main results: Higher medians of NEMA and Mallampati parameters were reported in patients with difficult intubation. AUC for Mallampati parameter was 0.733 while the NEMA parameter's AUC was 0.625. Sensitivity and specificity for Mallampati and NEMA parameter were respectively 0.79; 0.55 and 0.42; 0.75. Significantly higher MPN, RHTMD, Mallampati, and NEMA parameter were observed in patients in whom the BURP was used. Easy intubation occurs more frequently in patients with a history of OSAS or snoring than in those with difficult intubation.

Conclusion: It seems that none of the known bedside tests for predicting difficult intubation have a discriminating power sufficient for clinicians. Our study draws attention to a novel parameter, called NEMA, which appears to be a strong predictor of DEI, especially in combination with the Mallampati scale.

Keywords: Airway management; Laryngoscopy; Risk assessment; Tracheal intubation.