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Conventional sleep analysis relies primarily on electroencephalogram (EEG) waveform features assessed in concert with eye movements, respiration and muscle tone. We explore a complementary 'complexity domain' approach based on multiscale entropy (MSE) analysis of EEG signals and discuss its relationships to standard sleep analysis and to that based on electrocardiogram (ECG)-derived cardiopulmonary coupling (CPC). We observe a progressive decrease in complexity associated with decreased arousability, as measured by both conventional sleep scoring and CPC analysis. Furthermore, complexity analysis supports the contention that stage 2 non-REM sleep has distinct sub-phases that map to CPC high- and low-frequency coupled dynamics. © 2016 IEEE.

Abstract
An abrupt transition from sinus rhythm to atrial fibrillation (AF) is common in patients with chronic heart failure (CHF). We propose a conceptual framework for viewing this malignant transition in terms of a type of sublimation marked by the switch from highly periodic sinus interbeat interval dynamics characteristic of CHF to a state of random disorganization with AF. Sublimation of physical substances involves an increase in entropy via heat transfer. In contrast, the disease-related sublimation-like behavior involves a loss of information content, associated decreases in cardiac bioenergetic capacity and in multiscale entropy. © 2016 Wiley Periodicals, Inc. Complexity 21: 24–32, 2016. © 2016 Wiley Periodicals, Inc.

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Introduction: Pharyngocutaneous fistula after larynx and hypopharynx cancer surgery can cause serveral damages. This study's aim was to derive a clinical decision rule to predict pharyngocutaneous fistula development after pharyngolaryngeal cancer surgery. Methods: A retrospective cohort study was conducted, including all patients performing total laryngectomy/pharyngolaryngectomy (n = 171). Association between pertinent variables and pharyngocutaneous fistula development was assessed and a predictive model proposed. Results: American Society of Anesthesiologists scale, chemoradiotherapy, and tracheotomy before surgery were associated with fistula in the univariate analysis. In the multivariate analysis, only American Society of Anesthesiologists maintained statistical significance. Using logistic regression, a predictive model including the following was derived: American Society of Anesthesiologists, alcohol, N-classification, and diabetes mellitus. The model's score area under the curve was 0.76 (95% CI 0.64-0.87). The high-risk group presented specificity of 93%, positive likelihood ratio of 7.10, and positive predictive value of 76%. Including the medium-low, medium-high, and high-risk groups, a sensitivity of 92%, negative likelihood ratio of 0.25, and negative predictive value of 89% were observed. Conclusion: A clinical decision rule was created to identify patients with high risk of pharyngocutaneous fistula development. Prognostic accuracy measures were substantial. Nevertheless, it is essential to conduct larger prospective studies for validation and refinement.

Abstract
Objective: Pharyngocutaneous fistula is considered one of the major complications in the postoperative period after total laryngectomy/pharyngolaryngectomy, leading to a severe adverse impact for the patient and society. This study aimed to identify all the described pharyngocutaneous fistula predictive factors and risk classifications. Methods: Research was conducted to identify all the studies assessing predictive factors and risk classification for pharyngocutaneous fistula development published until April of 2012 (n = 846). The included studies were analyzed and data regarding their identification, methodological quality and results were recorded. Results: A total of 39 studies were included. The variables consistently reported as associated with fistula development were nutritional deficiency, American Society of Anesthesiologists (ASA) classification, high consumption of alcohol, anemia and hypoalbuminemia, co-morbidities, advanced N stage, location and extent of primary tumor, pre-radiotherapy and pre-chemoradiotherapy treatment, emergency tracheotomy, surgical margin status, surgery's duration, surgeon's experience, local complications of the wound, performance of intraoperative blood transfusion and relationship between nasogastric tube and oral feeding. Conclusion: Several risk factors were associated with pharyngocutaneous fistula formation in the included studies. However, there is still no consensus in the most pertinent selection. Only two classification systems were retrieved and they were not able to accurately predict pharyngocutaneous fistula.

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