Sleep study measures on post-operative night one following expansion pharyngoplasty for obstructive sleep apnea

Purpose: To examine the changes in measures of sleep apnea severity and hypoxemia on the first post-operative night (PON1) following expansion pharyngoplasty as a means to assess the safety of same day discharge after surgery.

Materials and methods: Prospective cohort study of subjects with moderate-severe obstructive sleep apnea who underwent expansion pharyngoplasty at a single academic sleep surgical practice. A WatchPAT study was performed on the night immediately following surgery (PON1) and comparisons were made to baseline sleep testing.

Results: Twenty subjects who had a mean age of 45.7 ± 10.8 years old and a mean body-mass index (BMI) of 31.4 ± 3.2 kg/m² were enrolled. Patients had baseline severe OSA with mean apnea hypopnea index (AHI) 39.4 ± 19.5/h, O2 nadir 80.8 ± 6.1 % and time with oxygen saturation below 88 % (T88) 12.3 ± 13.2 min. Measures of sleep apnea and nocturnal hypoxemia were not significantly different on PON1. AHI was increased by >20 % in 11 (55.0 %) patients. One patient demonstrated a >10 % worsening in O2 nadir, and 8 patients (45.0 %) demonstrated a >20 % worsening in T88. BMI over 32 was associated with elevated odds of worsening in T88, and anesthesia involving ketamine was associated with lower odds of a 20 % worsening in AHI or T88.

Conclusions: On PON1 following expansion pharyngoplasty, AHI and nocturnal hypoxemia are stable overall but variable on an individual basis. The decision for admission should therefore be made on a case-by-case basis. Further research is need to elucidate definitive predictors of worsening measures on PON1.