Continuous Positive Airway Pressure Titration During Pediatric Drug Induced Sleep Endoscopy

Objective: To observe the degree of airway collapse at varying levels of continuous positive airway pressure (CPAP) during drug pediatric induced sleep endoscopy. Methods: Using our institutional anesthesia protocol for pediatric DISE procedures, patients were anesthetized followed by evaluation of the nasal airway, nasopharynx, velum, hypopharynx, arytenoids, tongue base, and epiglottis. CPAP titration was performed under vision to evaluate the degree of airway collapse at the level of the velum. Comparison was made with pre-operative polysomnography findings. Results: Twelve pediatric patients underwent DISE with intraoperative CPAP titration. In 7/12 patients, DISE observed CPAP titration was beneficial in elucidating areas of obstruction that were observed at pressures beyond those recommended during preoperative sleep study titrations. In 3 patients, DISE observations provided a basis for evaluation in children not compliant with sleep study CPAP titration testing. With regard to regions effected, airway collapse was observed at the velum and oropharynx to a greater degree when compared with the tongue base and epiglottis. Conclusion: DISE evaluation of the pediatric patient with obstructive sleep apnea may present a source for further patient evaluation with respect to CPAP optimization and severity of OSA assessment, particularly in syndromic patients.

New Predictive Equation for Optimal Continuous Positive Airway Pressure in Adult Patients with Obstructive Sleep Apnea

Objective: This study aimed to develop and validate a new continuous positive airway pressure (CPAP) prediction equation and compare it with other formulas.Material and Methods: We retrospectively included patients with obstructive sleep apnea who underwent a CPAP titration study between January 2012 and December 2016. All clinical and polysomnographic data were collected. The new prediction equation was developed using the first data set, and the predictability performance was validated using the second data set.Results: Among the 266 enrolled patients, 73.7% were male, and the mean body mass index (BMI) was 30.8±7.4 kg/m2 . Five variables, namely age, BMI, neck circumference (NC), apnea–hypopnea index (AHI), and minimum pulse oxygen saturation (Min SpO2 ), highly correlated with the optimal titration pressure, and were therefore included in the equation, as stated below:Predicted pressure (cm H2 O) = 2.26 + (0.02xAge) + (0.04xBMI) + (0.11xNC) + (0.04xAHI) - (0.04xMin SpO2 )This equation accounted for 54.4% of the variance in predicting the optimal titration pressure (R2 =0.544, p-value <0.001). Its optimal estimation was 62.0% in the validated group. The equation-derived predicted pressure correlated with good agreement with the laboratory-derived optimal titration pressure (r=0.70, 95% CI=0.6335–0.755, p-value<0.001) according to Bland–Altman analysis. Conclusion: Our equation is highly consistent with the CPAP titration study in predicting fixed CPAP pressure, and is thereby beneficial for sleep technicians in establishing a starting pressure for such studies at a sleep laboratory.

843 Paradoxical Waking Hypoxemia that Improves with Sleep

Introduction We present a case of paradoxically worsened hypoxia during wake phase of polysomnography while undergoing a CPAP titration study. Nighttime hypoxemia is a common feature in obstructive sleep apnea, due to obstructive events that manifest while sleeping. Excluding OSA, there remains an extensive differential for disease processes that cause hypoxemia while asleep; however, none of these processes can explain waking hypoxemia that improves upon sleeping. Report of case(s) A 70 year old male with severe OSA diagnosed by home sleep test (REI 46.5, nadir O2=76%) underwent polysomnography with PAP titration and demonstrated several hours of interrupted sleep without hypoxia and minimal obstructive events on CPAP 9–13 cmH2O. During the study, while awake at CPAP of 14 cmH2O, he developed hypoxia to mid-high 80s and supplemental oxygen bleed in was added starting at 3L and increased to 5L during a prolonged period of wakefulness. On CPAP 15 cmmH2O with 5L bleed-in, the patient fell asleep and oxygen saturation again increased to low 90s. He underwent an extensive workup for other cardiopulmonary causes of hypoxemia, with pulmonary function testing showing moderate obstructive ventilatory defect and mild DLCO impairment. An echocardiogram with saline contrast bubble study was relatively unremarkable, without evidence of right to left shunting. He underwent a chest CTA which was negative for pulmonary embolism, though it did reveal an enlarged pulmonary artery consistent with pulmonary hypertension. His chronic hypoxemia was treated with 2L supplemental oxygen during the day and bleed-in with CPAP at night. Conclusion Though nocturnal hypoxemia is common with OSA, polysomnography with paradoxical hypoxemia during wake phase has not been reported. Notably, the patient was without prolonged hypoxia during his sleep phase while on CPAP treatment with minimal apneic/hypopneic events. Pulmonary hypertension can also present as nocturnal hypoxemia, but it should worsen with sleep, rather than improve. There are case reports of right to left shunting worsened by PAP, though his hypoxemia persisted despite PAP. His paradoxical worsening hypoxemia with wakefulness is still unexplained. Support (if any):

565 Adherence to Auto-Titrating CPAP in Children with Trisomy 21 and Obstructive Sleep Apnea

Introduction Obstructive sleep apnea (OSA) is common in children with trisomy 21. The pathophysiology can be multifactorial and challenging to manage. Auto-titrating continuous positive airway pressure (autoCPAP) is an emerging tool for the treatment of pediatric OSA and few studies discuss adherence. This study compares autoCPAP adherence in children with and without trisomy 21 at our center. We hypothesized that autoCPAP adherence would not differ between the two groups. Methods A retrospective review of patients aged 0 to 18 years with a diagnosis of OSA as defined by the International Classification of Sleep Disorders Third Edition, and empirically prescribed autoCPAP between 2012 and 2020 was conducted. Patients without available polysomnography or adherence data were excluded. Data included patient demographics, baseline polysomnography characteristics, and autoCPAP usage. Adherence was defined as usage ≥ 4 hours/night on 70% of nights during a consecutive 30-day period as per the Centers for Medicare and Medicaid Services criteria. Descriptive statistics and non-parametric tests were utilized for analysis. Results There were 130 total patients included with a mean age of 12.5 years ± a standard deviation of 4.1 years. Seventeen children (13%) had trisomy 21. No statistically significant differences were observed between the trisomy 21 group (T21) and the non-trisomy 21 group (non-T21) with respect to the obstructive apnea hypopnea index (9.5 ± 11.2 in T21, 14.7 ± 22.3 in non-T21, p=0.61), or the oxygen saturation nadir (87.8% ± 4.2% in T21, 84.4% ± 10.8% in non-T21, p=0.57). The percentage of days used ≥ 4 hours in a 30-day period did not significantly differ (52.3% ± 42% in T21, and 49.5% ± 37.5% in non-T21, p=0.64). While 41% of T21 subsequently underwent a CPAP titration for a suboptimal response to autoCPAP (for reasons including intolerance, persistent snoring, or daytime sleepiness), this did not differ significantly from 23% in non-T21 (p=0.11). Conclusion Although limited by a small sample size, our data suggest that adherence to autoCPAP did not differ between the trisomy 21 and non-trisomy 21 groups of children with OSA. Empiric autoCPAP is a reasonable treatment option for children with OSA who are not surgical candidates, including those with trisomy 21. Support (if any):

438 Rapid Eye Movement Rebound After Continuous Positive Airway Pressure in Co-Morbid Obstructive Sleep Apnea and Fibromyalgia

Introduction Fibromyalgia (FM) is a chronic pain condition that is associated with poor sleep quality and may present with obstructive sleep apnea (OSA). In OSA patients without FM, previous research has demonstrated a 57% relative increase in rapid eye movement (REM) sleep duration following treatment with continuous positive airway pressure (CPAP). However, there is limited data on REM rebound in patients with co-morbid FM and OSA. Patients with FM are often prescribed medication, like opioid analgesics, that decrease REM sleep. Additionally, pain perception may be altered by decreased REM duration. In the context of a national opioid crisis, it is imperative to explore how nonpharmacological options for treatment of co-morbid FM and OSA may improve REM sleep duration. Methods Following IRB approval at a university-affiliated teaching hospital, an electronic medical chart review was completed on patients diagnosed with FM and OSA who received polysomnography testing (PSG) and subsequent CPAP titration treatment. REM duration and REM total sleep time (TST) percentages were reviewed at baseline PSG and after CPAP titration. Results FM with OSA (n = 30). Mean age: 50.87, female: 28 (93%), male: 2 (7%). Baseline PSG: mean REM duration 34.47 minutes, mean REM TST 11.03%. After CPAP titration: mean REM duration 56.78 minutes, mean REM TST 18.84%. Pre- and post-CPAP titration REM TST percentage increased from 11.0% to 18.8%, indicating a mean difference of 7.8% (p &lt; 0.001) and a 71% relative increase in REM TST percentage duration. Conclusion These findings suggest delivery of CPAP to patients with FM and OSA improved REM sleep duration. The role of sleep in FM and pain severity is underexplored. Given the potential of chronic opioid use in patients with FM, treatment of OSA with CPAP may be a nonpharmacological alternative to pain management. Future studies are needed to see if REM rebound is associated with wellbeing, including perceived sleep quality and decreased pain perception. Support (if any):

Alternative Procedure to Individual Nasal Pressure Titration for Sleep Apnea

In the treatment of obstructive sleep apnea (OSA), the current standard of “CPAP titration” in the laboratory or at home is a resource demanding and costly approach that, in developed economies, markedly augments healthcare costs and in low resource economies precludes access to care altogether. Here, we discuss that current guidelines for titration of CPAP could be obviated by taking a different route that in many ways is similar to the institution of treatment in many other medical conditions. To this effect, we present novel population based data from 16,780 patients, showing that after individualized and labor-intensive and expensive CPAP titration, 86.4% of OSA patients are treated with nasal pressure settings within the range of 9 ± 2 cmH2O, and review the literature to justify the potential adoption of a standard therapeutic CPAP setting as the initial intervention which would be subsequently followed by any necessary adjustments in only a minority of patients who would not derive the necessary benefit from such standardized intervention. Assuming an 80–85% success rate as derived from our analyses, our personal view if extensively adopted could radically reduce healthcare costs and enable markedly improve access to diagnostics.