The minimal clinically important difference of the dyspnea index in laryngotracheal stenosis

Impact of BMI on Dyspnea and Need for Surgical Intervention in Bilateral Vocal Fold Immobility

OBJECTIVE

Bilateral vocal fold paralysis (BVFP) and posterior glottic stenosis (PGS) are causes of bilateral vocal fold immobility (BVFI) and may cause shortness of breath, stridor, and need for surgical intervention. Although increased body mass index (BMI) is associated with restrictive breathing patterns in patients with normal upper airways, it is unclear how BMI impacts dyspnea and need for surgical intervention in BVFI patients.

STUDY DESIGN

Retrospective cohort study.

SETTING

Three tertiary academic centers in the United States.

METHODS

Demographics, BMI, Dyspnea Index (DI), etiology, presence of tracheostomy and surgical intervention (dilation, tracheostomy, cordotomy, arytenoidectomy, open reconstruction) were collected. Primary outcomes included dyspnea measured by DI and need for surgery to improve airway. Linear regressions were performed to assess continuous outcomes. Mann-Whitney U-test was utilized to assess categorical outcomes.

RESULTS

Among 121 patients, 52 presented with BVFP and 69 with PGS. Previous neck surgery was the most common cause of BVFI (40.2%). 44.3% of patients received a tracheostomy. Through multivariate linear regression, increased BMI was significantly associated with increased DI in the entire cohort (β = .43, P = .016). Increased BMI was also associated with need for any surgical intervention (odds ratio [OR] = 1.07, 95% confidence interval [CI] = [1.01-1.13]) in the overall cohort. When stratifying our data, BMI was only significantly associated with DI in BVFP (β = .496) and need for surgical intervention in PGS (OR = 1.11, 95% CI = [1.01-1.21]), although a positive trend was seen in all analyses.

CONCLUSION

Increased BMI may correlate with worsening dyspnea symptoms and need for surgical intervention in patients with BVFI. Weight-loss-related counseling may benefit symptom management.

Variability in Minimal Clinically Important Difference Calculation and Reporting in the Otolaryngology Literature

OBJECTIVE

Best practices for calculation of the minimal clinically important difference (MCID) of outcome measures include the use of complementary methodologies (broadly classified as anchor-based and distribution-based) and reporting of the MCID's predictive ability. We sought to determine MCID calculation and reporting patterns within the otolaryngology literature.

METHODS

A systematic search strategy of Embase, PubMed, and Web of Science databases was developed and implemented to identify studies reporting the determination of an MCID for an outcome measure. Studies specifically within the otolaryngology literature (defined as journals classified as "otorhinolaryngology" in the Journal Citation Reports database) were included. All those journals were additionally searched for relevant articles.

RESULTS

There were 35 articles that met the inclusion criteria. Of these studies, 88.6% reported MCID of a patient-reported outcome measure and the remainder were for objective outcome measurements. Anchor-based methods were used by 82.9% of studies and distribution-based methods were used by 68.6% of studies. Of all studies, 31.4% utilized anchor-based methods alone, 17.1% utilized distribution-based methods alone, and 51.4% used both methods. Only 25.7% of studies reported the sensitivity (median: 60.8%, range: 40.5%-86.7%) and specificity (median: 80.4%, range: 63.5%-88.0%) of the MCID to detect patients experiencing clinically important change.

CONCLUSION

Deviation from best practices in MCID calculation and reporting exists within the otolaryngology literature, with almost half of all studies only using one method of MCID calculation and almost three-quarters not reporting the predictive ability (sensitivity/specificity) of the calculated MCID. When predictive ability is reported, however, MCIDs appear to be more specific than sensitive.

LEVEL OF EVIDENCE

NA Laryngoscope, 134:2059-2069, 2024.

Novel Respiratory Therapy for the Improvement of Post COVID Condition Symptoms: A Case Series

INTRODUCTION

Speech-language pathologists are seeing a growing number of patients whose voice and upper airway symptoms are complicated by dyspnea, cognitive difficulties, anxiety, extreme fatigue, and other debilitating post COVID symptoms. These patients are often less responsive to traditional speech-language pathology treatments and there is emerging literature that suggests dysfunctional breathing (DB) might contribute to dyspnea and other symptoms in this patient population. Treatment of DB through breathing retraining has been shown to improve breathing and successfully reduce symptoms similar to those seen in patients with long COVID. There is some preliminary evidence that breathing retraining is helpful for patients with post COVID condition symptoms. However, breathing retraining protocols tend to be heterogeneous and are often not systematic or well described.

METHODS

This case series reports on an Integrative Breathing Therapy (IBT) protocol used in patients diagnosed with post COVID condition symptoms attending an otolaryngology clinic who presented with signs and symptoms of DB. A systematic evaluation of the biomechanical, biochemical, and psychophysiological dimensions of DB based on principles of IBT was performed on each patient to enable targeted patient-centered care. Patients were then provided with intensive breathing retraining that aimed to comprehensively improve breathing functionality in all these three dimensions of breathing. Treatment involved 6-12 sessions of weekly 1-hour group telehealth sessions combined with 2-4 individual sessions.

RESULTS

All participants showed improvements in the parameters of DB measured and also reported a reduction in symptoms and improved daily function.

CONCLUSIONS

These findings suggest that patients with long COVID who present with signs and symptoms of DB might respond positively to comprehensive and intensive breathing retraining that addresses biochemical, biomechanical, and psychophysiological dimensions of breathing. More research is required to further refine this protocol and confirm its effectiveness through a controlled trial.

Effect of Medialization on Dyspnea Index in Unilateral Vocal Fold Paralysis

OBJECTIVE

Patients with unilateral vocal fold paralysis commonly report dysphonia and dysphagia. Dyspnea also occurs, with studies on treatment-related change producing mixed results. Studies including patient-reported outcomes have focused on single-question global scales. The Dyspnea Index (DI) includes 10 questions, is specific to upper airway-related dyspnea, and may better capture these patients' symptoms. We evaluated change in DI after treatment.

STUDY DESIGN

Retrospective review.

SETTING

Academic medical center.

METHODS

Forty-three patients with unilateral vocal fold paralysis underwent injection augmentation (n = 25) or framework surgery (n = 18). DI was recorded preprocedure, 2 to 4 weeks afterward, and at approximately 3 months afterward in 19 patients. Voice Handicap Index-10, Glottal Function Index, Cough Severity Index, and Eating Assessment Tool-10 were also recorded. Change in parameters and correlations were assessed. Obesity, cardiac disease, pulmonary disease, and procedure (injection vs framework surgery) were evaluated for effect on DI.

RESULTS

Twenty-four patients had an abnormal baseline DI (>10). DI decreased from 14.9 ± 13.8 to 6.5 ± 9.3 after treatment (P < .001; 95% CI, 4.7-12.1). Twenty-eight scores decreased, 9 remained unchanged, and 6 increased. Change in DI was influenced by the presence of cardiac disease. Decreased DI persisted at 3-month follow-up. Voice Handicap Index-10, Glottal Function Index, Cough Severity Index, and Eating Assessment Tool-10 scores decreased and were correlated with change in DI.

CONCLUSION

Upper airway-related dyspnea is common in unilateral vocal fold paralysis, occurring in half of this cohort. Correcting glottic insufficiency may alleviate symptoms. Treatment decision making should consider postprocedural change in dyspnea, especially in patients for whom dyspnea is a motivating factor for seeking treatment.

Pulmonary Function Tests May Better Predict Dyspnea-Severity in Patients with Subglottic Stenosis Compared to Clinician-Reported Stenosis

OBJECTIVE

Patients with subglottic stenosis (SGS) present with varied degree of breathing complaints. The dyspnea index (DI) is a 10-question patient-reported outcome measure designed to measure the severity of upper airway obstruction. We set out to determine whether pulmonary function tests or clinician-reported degree of stenosis best predicted DI scores.

METHODS

Thirty patients with SGS were retrospectively reviewed over a 6-year period. One visit from each patient was included. Data including peak expiratory flow rate (PEFR), body-mass index (BMI), clinician-reported degree of stenosis, and DI scores were reviewed. Multiple linear regression was performed to determine how degree of stenosis and PEFR % predicted the variation in DI score.

RESULTS

PEFR % better predicted DI scores compared to degree of stenosis (partial correlation -0.32 vs 0.17). After stepwise elimination, PEFR % remained in the regression and was significantly associated with DI scores (F[1, 29] = 9.38, P = .005). BMI did not demonstrate a linear relationship with DI scores and was not included in the regression (r = -.02). The PEFR % unstandardized coefficient was -0.25 (95% CI: -0.42 to -0.08, P = .005). The model predicts that a 4% increase in the PEFR % results in a 1-point decrease in the DI score (95% CI: -1.68 to -0.32).

CONCLUSION

This study suggests that pulmonary function tests may be a better in-office measure to substantiate the severity of symptoms in patients with SGS.