The Clinical Anatomy of Cricothyroid Membrane, Its Relevance To Emergency Subglottic Procedures

Precise anatomical knowledge is essential for successful emergency cricothyrotomy. However, most protocols assume that anatomical data from Western populations are universal. To address this, our study measured cricothyroid membrane dimensions in Nigerian adults and compared them with international standards. We analysed 148 cadaveric specimens (89 males, 59 females, aged 22–76) from three central Nigerian university anatomy departments between January 2023 and June 2024. Using digital callipers, vertical height, transverse width, and membrane thickness were measured at standardised locations. The researchers analysed the data using multiple linear regression in R 4.3.1, with demographic predictors. Compared to international standards, Nigerian specimens had lower vertical height (8.7±1.4 mm vs 9.8±1.2 mm; Cohen's d = −0.83, 95% CI: −1.00 to −0.66, p < 0.001), representing an 11.2% reduction. Membrane thickness was higher (4.3±0.8mm vs 2.8±0.6mm; Cohen's d = 2.09, 95% CI: 1.86–2.32, p<0.001), a 46.4% increase. Males had greater vertical height than females (9.2 mm vs 7.8 mm, p < 0.001). Ethnic differences were also observed, with Igbo specimens differing most from international norms. These significant morphometric differences indicate that Nigeria needs emergency airway protocols tailored to its population.