The role of drug-induced sleep endoscopy in the diagnosis and management of obstructive sleep apnoea syndrome: our personal experience

Nowadays, drug-induced sleep endoscopy (DISE) is performed widely and its validity and reliability has been demonstrated by several studies; in fact, it provides clinical information not available by routine clinical inspection alone. Its safety and utility are promising, but still needs to be improved to reach the level of excellence expected of gold standard tests used in clinical practice. Our study compares the results of clinical and diagnostic evaluation with those of sleep endoscopy, evaluating the correlation between clinical indexes of routine clinical diagnosis and sites of obstruction in terms of number of sites involved, entity of obstruction and pattern of closure. This study consists in a longitudinal prospective evaluation of 138 patients who successfully underwent sleep endoscopy at our institution. Patients were induced to sleep with a low dose of midazolam followed by titration with propofol. Sedation level was monitored using bispectral index monitoring. Our results suggest that the multilevel complete collapse was statistically significantly associated with higher apnoea hypopnea index values. By including partial sites of obstruction greater than 50%, our results also suggest that multilevel collapse remains statistically and significantly associated with higher apnoea hypopnoea index values. Analyzing BMI distribution based on number of sites with complete and partial obstruction there was no significant difference. Finally, analyzing Epworth Sleepiness Score distribution based on number of sites with complete obstruction, there was a statistically significant difference between patients with 3-4 sites of obstruction compared to those with two sites or uni-level obstruction. In conclusion, our data suggest that DISE is safe, easy to perform, valid and reliable, as previously reported. Furthermore, we found a good correlation between DISE findings and clinical characteristics such as AHI and EPS. Consequently, adequate assessment by DISE of all sites of obstruction is very important, not only in patients with low-moderate AHI and EPS, but also in patients with a high AHI or/and high EPS, in particular to plan multilevel surgery that in these latter situations is more demanding since success may be harder to achieve.