Hour-to-hour variability of respiratory sleep indices and ambulatory blood pressure.

STUDY OBJECTIVES: Respiratory sleep indices are traditionally reported on the basis of the average total sleep time. The relationship between the hour-to-hour variability of these parameters and blood pressure (BP) has not been reported. METHODS: We evaluated the associations of the hour-to-hour variability of the apnea-hypopnea index (AHI), oxygen desaturation index (ODI), and lowest oxygen saturation with the 24-h ambulatory BP in patients with hypertension and newly diagnosed obstructive sleep apnea. A total of 147 patients underwent polysomnography, based on which obstructive sleep apnea was diagnosed in 106 patients; these patients underwent 24-h ambulatory BP monitoring within the next 30 days. Each polysomnogram was divided into hourly reports to calculate the variability of the respiratory sleep indices. Variability independent of the mean was considered the primary measure of variability. RESULTS: The median number of hourly polysomnogram reports was 7 (range, 4-8). The hour-to-hour variability of both AHI and ODI, but not of the lowest oxygen saturation, was correlated with the 24-h pulse pressure, 24-h systolic BP, and awake systolic BP (p < 0.05 for all). The fully adjusted linear regression analysis indicated that the hour-to-hour variability of AHI and ODI remained associated with the 24-h pulse pressure (AHI: ß coefficient, 0.264 [95% CI = 0.033-0.495], p = 0.026; ODI: ß coefficient, 0.450 [95% CI = 0.174-0.726], p = 0.002). CONCLUSIONS: The hour-to-hour variability of AHI and ODI is independently associated with the 24-h pulse pressure. Further investigations are warranted to evaluate the clinical relevance of this new-found association.

Thoracolumbar Injury Classification and Severity Score Is Predictive of Perioperative Adverse Events in Operatively Treated Thoracic and Lumbar Fractures

Methods@#We performed a retrospective review of 199 patients with surgically treated thoracolumbar fractures operated between January 2007 and January 2018. The potential risk factors for the development of AEs as well as the development of common complications were evaluated by univariate analysis, and a multivariate logistic regression analysis was performed to identify independent risk factors predictive of the above. @*Results@#The overall rate of AEs was 46.7%; 83 patients (41.7%) had nonsurgical AEs, whereas 24 (12.1%) had surgical adverse events. The most common AEs were urinary tract infections in 43 patients (21.6%), and hospital-acquired pneumonia in 21 patients (10.6%). On multivariate logistic regression, a Thoracolumbar Injury Classification and Severity (TLICS) score of 8–10 (odds ratio [OR], 6.39; 95% confidence interval [CI], 2.33–17.51), the presence of polytrauma (OR, 2.64; 95% CI, 1.17–5.99), and undergoing open surgery (OR, 2.31; 95% CI, 1.09–4.88) were significant risk factors for AEs. The absence of neurological deficit was associated with a lower rate of AEs (OR, 0.47; 95% CI, 0.31–0.70). @*Conclusions@#This study suggests the presence of polytrauma, preoperative American Spinal Injury Association score, and TLICS score are predictive of AEs in patients with surgically treated thoracolumbar fractures. The results might also suggest a role for minimally invasive surgical methods in reducing AEs in these patients.