Normative Values and Interrelationship of MDVP Voice Analysis Parameters Before and After Endotracheal Intubation.

Purpose: The Multi-Dimensional Voice Program (MDVP) is used for assessment of voice quality. A simple procedure for MDVP recordings was used in a randomized clinical trial (RCT) on induced vocal fold trauma due to intubation. This secondary study compares the common MDVP parameters with other normative values for adults and investigates the correlation between these MDVP parameters in relation to the "standardized" trauma of endotracheal intubation.

Methods: Preoperative and postoperative assessments of vocal fold pathology with flexible videolaryngoscopy and voice analysis with MDVP using the best-of-three standardized recording were performed in 121 patients with normal voices included consecutively in the RCT. The procedures of anesthesia were standardized.

Results: The normative MDVP values of this study are consistently lower compared with most normative values presented in other studies. The preoperative to postoperative differences in jitter values (jitter and relative average perturbation) were closely correlated to the shimmer values for patients with postoperative vocal fold edemas. In the patients with edema, the preoperative to postoperative differences in jitter had a correlation coefficient of 0.95 (P < 0.0001) to the difference in shimmer, compared with a correlation coefficient of 0.39 (P < 0.0001) in the patients without edema.

Conclusions: This study supports the use of the "Best-of-Three" procedures for precise and relevant MDVP parameter calculations. The MDVP parameters, with closely correlated changes in jitter and shimmer values, accurately reflect the induced vocal fold edema when using the preoperative to postoperative changes.