0883 RELATIONSHIP BETWEEN PAIN AND POLYSOMNOGRAPHIC MEASURES IN PEDIATRIC OBSTRUCTIVE SLEEP APNEA PATIENTS

Abstract

Introduction: In children with OSA, lower SpO2% nadir is predictive of less need for post-adenotonsillectomy morphine. However, in adults with severe OSA, CPAP increases pain tolerance. Opposing effects of OSA-related sleep fragmentation and hypoxemia on pain perception were hypothesized. We tested a relationship between pain and PSG variables in children evaluated for OSA. Method(s): On PSG evening, parents of 66 children (28 girls, 52 minorities, 2-17y.o., no neurological, endocrine, psychiatric conditions) and 50 children >=5 y.o. used PedsQL to rate intensity (average of present and past 7 days) and frequency (average of past week and month) of the children's pain experience. On PSG evening and following morning, all children reported pain levels using FACES scale, and for 21 children forearm pressure pain threshold (PPTh) was measured. Each pain measure was regressed on sleep efficiency (SE), awakenings, arousal index (ArI), N1%, AHI, SpO2% nadir, time spent below SpO2 90% (TimeO2<90%) and desaturation index. Sex, age and BMI were used as covariates, wherever significant. Result(s): Mean AHI=7.3 +/- 10.5. Higher parent-rated pain intensity was associated with greater TimeO2<90% (p=0.02). Higher childrated pain intensity was associated with greater N1% (p=0.03), while pain frequency, with greater TimeO2<90% (p=0.002) and N1% (p=0.003). Higher evening FACES were associated with higher ArI (p=0.05), while higher morning FACES, with higher AHI (p=0.001) and N1% (p=0.02), lower SE (p=0.005) and ArI (p<0.001). Morning PPTh showed greater pain tolerance with lower SpO2% nadir (p=0.04). Conclusion(s): Time spent below SpO2 90% relates to greater pain ratings, while lower SpO2% nadir relates to greater pain tolerance on a psychophysical test, suggesting opposite effects of apnea-related hypoxemia on different pain measures. Sleep disturbance, as captured in sleep efficiency and stage N1% measures, and respiratory event frequency appear to increase pain ratings, although acute and chronic effects of arousals may differ.