A systematic review and meta-analysis of the correlation between operation time and postoperative delirium in total hip arthroplasty.

BACKGROUND: Delirium is a common postoperative complication of total hip arthroplasty (THA), excessively long time surgery may be one of the factors associated with it. This article aimed to employ literature retrieval and meta-analysis to investigate the correlation between operation time and postoperative delirium in THA. METHODS: The databases of PubMed and Springerlink libraries were searched for retrospective case-control studies on delirium-related factors after THA. The retrieved studies were screened according to the inclusion criteria. Newcastle-Ottawa scale (NOS) was used to assess the quality of literatures. After extracting the data of included literatures, RevMan 5.3.5 software was used to analyze the data and obtain a forest plot and funnel plot. RESULTS: A total of 137 literatures were initially screened in this study. According to the inclusion and exclusion criteria and literature quality evaluation, 6 studies were finally included, involving a total of 3,494 patients. The NOS scores were above 6 points in all 6 literatures. Meta-analysis revealed statistical heterogeneity among the 6 studies (I2=80%, P=0.0002). The random effects model was used, revealing that the operation time of patients with postoperative delirium was longer, and the difference was statistically significant [standardized mean difference (SMD) =0.43, 95% confidence interval (CI): 0.20 to 0.66, P=0.0003]. The 6 studies were divided into unilateral or bilateral THA subgroups according to the type of surgery. Homogeneity was detected between the internal literatures: bilateral subgroup (I2=5%, P=0.37), unilateral subgroup (I2=0%, P=0.78). Postoperative delirium was associated with longer operation time in both subgroups, which was consistent with the combined analysis: bilateral subgroup (SMD =0.25, 95% CI: 0.12 to 0.37, P=0.0001), unilateral subgroup (SMD =0.70, 95% CI: 0.55 to 0.84, P=0.0001). DISCUSSION: Operation time is one of the related factors of delirium after THA. The longer the operation time, the greater the possibility of delirium.

Edge-aware spatial-frequency extrapolation for consecutive block loss.

To improve the spatial error concealment (SEC) for consecutive block loss, an edge-aware spatial-frequency extrapolation (ESFE) algorithm and its edge-guided parametric model are proposed by selectively incorporating the Hough-based edge synthesis into the frequency-based extrapolation architecture. The dominant edges that cross the missing blocks are firstly identified by the Canny detector, and then the robust Hough transformation is utilized to systematically connect these discontinuous edges. During the generation of edge-guided parametric model, the synthesized edges are utilized to divide the missing blocks into the structure-preserving regions, and thus the residual error is reliably reduced. By successively minimizing the weighted residual error and updating the parametric model, the known samples are approximated by a set of basis functions which are distributed in a region containing both known and unknown samples. Compared with other state-of-the-art SEC algorithms, experimental results show that the proposed ESFE algorithm can achieve better reconstruction quality for consecutive block loss while keeping relatively moderate computational complexity.