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Clinical Protocol for Accelerated Hypoglossal Nerve Stimulation Titration Using Longitudinal Home Sleep Apnea Testing
Ruchir P. Patel, M.D., Chelsie Rohrscheib, Ph.D.
Affiliations: The Insomnia and Sleep Institute of Arizona
Study Objectives: Hypoglossal nerve stimulation (HGNS) is an established therapy for patients with moderate to severe obstructive sleep apnea (OSA) who are unable to tolerate positive airway pressure therapy. While effective, optimization of HGNS therapy requires a titration period that traditionally spans 90–120 days and relies on infrequent in-laboratory assessments. Prolonged titration may delay symptom relief, increase clinical burden, and expose patients to periods of suboptimal or excessive stimulation. The objective of this clinical protocol case series was to evaluate whether frequent, longitudinal monitoring using a home sleep apnea testing (HSAT) system (Wesper Lab) could safely shorten the HGNS titration period while maintaining or improving clinical outcomes, as measured by apnea–hypopnea index (AHI) and oxygen saturation.
Methods: Thirty adult patients undergoing HGNS titration following Inspire implantation at a sleep clinic in Arizona were enrolled between January and October 2023. All patients met standard clinical criteria for HGNS therapy and were undergoing post-implant activation and titration. Titration Protocol: The optimized titration protocol incorporated frequent longitudinal assessment using Wesper Lab HSAT. The Inspire device was activated approximately three weeks following implantation. After activation, stimulation amplitude was increased in increments of 0.1 V every two to four days, contingent on patient tolerance. Patients were instructed to perform a Wesper HSAT on the second night following each stimulation adjustment. Data from these tests were reviewed to assess objective changes in OSA severity and oxygenation. Wesper-derived metrics, including AHI and minimum oxygen saturation, were reviewed to guide subsequent stimulation adjustments. When patients demonstrated sustained improvement and reported symptom resolution, an in-laboratory titration polysomnography was performed between 10 and 12 weeks post-activation to confirm optimal device settings. Outcome Measures: The primary outcomes of interest were 1. duration of the HGNS titration period (days from activation to final titration), 2. change in AHI from baseline to post-titration, 3. percentage of patients completing titration within 60 and 90 days, and 4. change in minimum oxygen saturation. Safety was assessed through clinical follow-up and review of patient-reported tolerance during titration.
Results: Implementation of the optimized protocol substantially reduced the duration of HGNS titration. The mean titration time was 63 days, compared with the traditional 90–120 day Inspire-recommended timeline (Figure 1). Overall, 86.6% of patients completed titration within 90 days, and 60% completed titration within 60 days (Figure 2). Patients experienced significant improvements in OSA severity during the titration period. Mean AHI was reduced by 68%, corresponding to an average decrease of 15.21 events per hour. This exceeded the 50% reduction commonly cited as a benchmark for HGNS treatment success (Figure 3). Patients demonstrated improvement in nocturnal oxygenation. Minimum oxygen saturation increased by an average of 4.31%, indicating improved physiologic stability during sleep.
Figure 1: Average HGNS titration duration using the optimized longitudinal monitoring protocol compared with the traditional Inspire-recommended protocol.
Figure 2: Proportion of patients completing HGNS titration within ≤60 days, ≤90 days, and ≥90 days using the optimized protocol.
Figure 3. Percent reduction in AHI achieved with the optimized titration protocol compared with benchmark expectations.