Long-Standing Themes and Future Prospects for the Inspection and Maintenance of Façade Falling Objects from Tall Buildings.

The increasing number of accidents arising from falling objects from the façade of tall buildings has attracted much attention globally. To regulators, a preventive approach based on a mandatory periodic façade inspection has been deemed as a necessary measure to maintain the functionality and integrity of the façade of tall buildings. Researchers worldwide have been working towards a predictive approach to allow for the assessment of the likely failure during some future period, by measuring the condition of the façade to detect latent defects and anomalies. The methods proposed include laser scanning, image-based sensing and infrared thermography to support the automatic façade visual inspection. This paper aims to review and analyse the state-of-the-art literature on the automated inspection of building façades, with emphasis on the detection and maintenance management of latent defects and anomalies for falling objects from tall buildings. A step-by-step holistic method is leveraged to retrieve the available literature from databases, followed by the analyses of relevant articles in different long-standing research themes. The types and characteristics of façade falling objects, legislations, practices and the effectiveness of various inspection techniques are discussed. Various diagnostic, inspection and analytical methods which support façade inspection and maintenance are analysed with discussion on the potential future research in this field.

BIM and Data-Driven Predictive Analysis of Optimum Thermal Comfort for Indoor Environment.

Mechanical ventilation comprises a significant proportion of the total energy consumed in buildings. Sufficient natural ventilation in buildings is critical in reducing the energy consumption of mechanical ventilation while maintaining a comfortable indoor environment for occupants. In this paper, a new computerized framework based on building information modelling (BIM) and machine learning data-driven models is presented to analyze the optimum thermal comfort for indoor environments with the effect of natural ventilation. BIM provides geometrical and semantic information of the built environment, which are leveraged for setting the computational domain and boundary conditions of computational fluid dynamics (CFD) simulation. CFD modelling is conducted to obtain the flow field and temperature distribution, the results of which determine the thermal comfort index in a ventilated environment. BIM-CFD provides spatial data, boundary conditions, indoor environmental parameters, and the thermal comfort index for machine learning to construct robust data-driven models to empower the predictive analysis. In the neural network, the adjacency matrix in the field of graph theory is used to represent the spatial features (such as zone adjacency and connectivity) and incorporate the potential impact of interzonal airflow in thermal comfort analysis. The results of a case study indicate that utilizing natural ventilation can save cooling power consumption, but it may not be sufficient to fulfil all the thermal comfort criteria. The performance of natural ventilation at different seasons should be considered to identify the period when both air conditioning energy use and indoor thermal comfort are achieved. With the proposed new framework, thermal comfort prediction can be examined more efficiently to study different design options, operating scenarios, and changeover strategies between various ventilation modes, such as better spatial HVAC system designs, specific room-based real-time HVAC control, and other potential applications to maximize indoor thermal comfort.

Update on surgical sepsis syndrome.

BACKGROUND: Sepsis is a serious complication in surgical patients, and is associated with prolonged hospital stay and high mortality rates. The definitions of sepsis have been revisited recently. This article reviews how definitions have changed over the years, and provides an update on basic pathobiology and essential aspects of treatment. METHODS: PubMed was searched for reports published in English before October 2016, using the search terms 'surgical sepsis' AND 'surgical ICU'. The reference lists of articles identified in the search were also checked. Other relevant literature was selected based on personal knowledge of developments in the field of sepsis. RESULTS: Sepsis is defined as the presence of infection plus associated organ dysfunction. It occurs as the result of a dysregulated host response to the infection. Prevention of infection is an important means of limiting the development of sepsis. Treatment relies on source control, appropriate antibiotics and organ support. Research continues in an attempt to identify effective immunomodulatory therapies. CONCLUSION: Sepsis is an important and serious complication of surgery, and precautions must be taken to try to prevent infection in surgical patients. If sepsis develops, rapid diagnosis is crucial so that appropriate source control, antimicrobial therapy and organ support can be started early in the course of disease. New techniques enabling a better classification of a patient's particular sepsis profile will enable more personalized therapy.

Preoperative abnormalities in serum sodium concentrations are associated with higher in-hospital mortality in patients undergoing major surgery.

BACKGROUND: Abnormal serum sodium concentrations are common in patients presenting for surgery. It remains unclear whether these abnormalities are independent risk factors for postoperative mortality. METHODS: This is a secondary analysis of the European Surgical Outcome Study (EuSOS) that provided data describing 46 539 patients undergoing inpatient non-cardiac surgery. Patients were included in this study if they had a recorded value of preoperative serum sodium within the 28 days immediately before surgery. Data describing preoperative risk factors and serum sodium concentrations were analysed to investigate the relationship with in-hospital mortality using univariate and multivariate logistic regression techniques. RESULTS: Of 35 816 (77.0%) patients from the EuSOS database, 21 943 (61.3%) had normal values of serum sodium (138-142 mmol litre(-1)) before surgery, 8538 (23.8%) had hyponatraemia (serum sodium ≤137 mmol litre(-1)) and 5335 (14.9%) had hypernatraemia (serum sodium ≥143 mmol litre(-1)). After adjustment for potential confounding factors, moderate to severe hypernatraemia (serum sodium concentration ≥150 mmol litre(-1)) was independently associated with mortality [odds ratio 3.4 (95% confidence interval 2.0-6.0), P<0.0001]. Hyponatraemia was not associated with mortality. CONCLUSIONS: Preoperative abnormalities in serum sodium concentrations are common, and hypernatraemia is associated with increased mortality after surgery. Abnormalities of serum sodium concentration may be an important biomarker of perioperative risk resulting from co-morbid disease.

Effect of empiric antibiotic treatment on plasma endotoxin activity in septic patients.

OBJECTIVES: Efficient empiric antibiotic therapy remains the cornerstone of sepsis treatment. However, antibiotics could be responsible for the transient clinical deterioration provoked by the release of bacterial cell-wall constituents, such as endotoxin, into the blood stream. The aim of this study was to evaluate if a transient elevation of endotoxin level occurred in septic patients following antibiotic administration. METHODS: Thirty-three septic intensive care unit (ICU) patients were enrolled in this prospective trial. Four blood samples were collected from each of these patients during a 24-h period, and endotoxin activity was measured in these samples by the chemiluminescence technique. Fifteen ICU non-septic patients and 15 healthy volunteers were also observed for possible daily fluctuations in endotoxin activity. RESULTS: There was no significant increase in endotoxin levels following the initiation of empiric antibiotic therapy in septic patients. A clinical deterioration in the 4 h following antibiotic administration was observed in 14 septic patients (42 %). These patients had significantly higher endotoxin levels than stable septic patients. CONCLUSIONS: Although endotoxin levels failed to increase after the administration of antibiotic(s) to critically ill patients, they were higher in the septic patients presenting a transient deterioration than in the other patients. This observation suggests that a possible release of endotoxin due to bacteria lysis by antibiotics could be responsible for the observed clinical deterioration.

Isotonic crystalloid solutions: a structured review of the literature.

BACKGROUND: Several different crystalloid solutions are available for i.v. fluid administration but there is little information about their specific advantages and disadvantages. METHODS: We performed a systematic search of MEDLINE, EMBASE, and CENTRAL up until May 17, 2012, selecting all prospective human studies that directly compared any near-isotonic crystalloids and reported any outcome. RESULTS: From the 5060 articles retrieved in the search, only 28 met the selection criteria. There was considerable heterogeneity among the studies. Several articles reported an increased incidence of hyperchloraemic acidosis with the use of normal saline, and others an increase in blood lactate levels when large amounts of Ringer's lactate solutions were infused. From the limited data available, normal saline administration appears to be associated with increased blood loss and greater red blood cell transfusion volumes in high-risk populations compared to Ringer's lactate. Possible effects of the different solutions on renal function, inflammatory response, temperature, hepatic function, glucose metabolism, and splanchnic perfusion are also reported. The haemodynamic profiles of all the solutions were similar. CONCLUSIONS: Different solutions have different effects on acid-base status, electrolyte levels, coagulation, renal, and hepatic function. Whether these differences have clinical consequences remains unclear.

Four phases of intravenous fluid therapy: a conceptual model.

I.V. fluid therapy plays a fundamental role in the management of hospitalized patients. While the correct use of i.v. fluids can be lifesaving, recent literature demonstrates that fluid therapy is not without risks. Indeed, the use of certain types and volumes of fluid can increase the risk of harm, and even death, in some patient groups. Data from a recent audit show us that the inappropriate use of fluids may occur in up to 20% of patients receiving fluid therapy. The delegates of the 12th Acute Dialysis Quality Initiative (ADQI) Conference sought to obtain consensus on the use of i.v. fluids with the aim of producing guidance for their use. In this article, we review a recently proposed model for fluid therapy in severe sepsis and propose a framework by which it could be adopted for use in most situations where fluid management is required. Considering the dose-effect relationship and side-effects of fluids, fluid therapy should be regarded similar to other drug therapy with specific indications and tailored recommendations for the type and dose of fluid. By emphasizing the necessity to individualize fluid therapy, we hope to reduce the risk to our patients and improve their outcome.

Beyond single-marker analyses: mining whole genome scans for insights into treatment responses in severe sepsis.

Management of severe sepsis, an acute illness with high morbidity and mortality, suffers from the lack of effective biomarkers and largely empirical predictions of disease progression and therapeutic responses. We conducted a genome-wide association study using a large randomized clinical trial cohort to discover genetic biomarkers of response to therapy and prognosis utilizing novel approaches, including combination markers, to overcome limitations of single-marker analyses. Sepsis prognostic models were dominated by clinical variables with genetic markers less informative. In contrast, evidence for gene-gene interactions were identified for sepsis treatment responses with genetic biomarkers dominating models for predicting therapeutic responses, yielding candidates for replication in other cohorts.

Development of acute kidney injury during continuous infusion of vancomycin in septic patients.

PURPOSE: Few data are available on the occurrence of renal failure during continuous infusion of vancomycin in critically ill patients. METHODS: We reviewed the data of all patients admitted to the intensive care unit (ICU) between January 2008 and December 2009 in whom vancomycin was given as a continuous infusion for more than 48 h in the absence of renal replacement therapy. We collected data on the doses of vancomycin and blood concentrations during therapy. Acute kidney injury (AKI) was defined as a daily urine output <0.5 ml/kg/h and/or an increase in the serum creatinine of ≥0.3 mg/dl from baseline levels during vancomycin therapy or within 72 h after its discontinuation. Multivariable logistic regression analysis was performed to identify predictors of AKI. RESULTS: Of 207 patients who met the inclusion criteria, 50 (24 %) developed AKI. These patients were more severely ill, had lower creatinine clearance at admission, were more frequently exposed to other nephrotoxic agents, had a longer duration of therapy, and had higher concentrations of vancomycin during the first 3 days of treatment (C(mean)). The C(mean) was independently associated with early AKI (within 48 h from the onset of therapy) and the duration of vancomycin administration with late AKI. CONCLUSIONS: AKI occurred in almost 25 % of critically ill patients treated with a continuous infusion of vancomycin. Vancomycin concentrations and duration of therapy were the strongest variables associated with the development of early and late AKI during therapy, respectively.

Intrinsic functional architecture in the anaesthetized monkey brain.

The traditional approach to studying brain function is to measure physiological responses to controlled sensory, motor and cognitive paradigms. However, most of the brain's energy consumption is devoted to ongoing metabolic activity not clearly associated with any particular stimulus or behaviour. Functional magnetic resonance imaging studies in humans aimed at understanding this ongoing activity have shown that spontaneous fluctuations of the blood-oxygen-level-dependent signal occur continuously in the resting state. In humans, these fluctuations are temporally coherent within widely distributed cortical systems that recapitulate the functional architecture of responses evoked by experimentally administered tasks. Here, we show that the same phenomenon is present in anaesthetized monkeys even at anaesthetic levels known to induce profound loss of consciousness. We specifically demonstrate coherent spontaneous fluctuations within three well known systems (oculomotor, somatomotor and visual) and the 'default' system, a set of brain regions thought by some to support uniquely human capabilities. Our results indicate that coherent system fluctuations probably reflect an evolutionarily conserved aspect of brain functional organization that transcends levels of consciousness.

Evaluation of cardiac output in intensive care using a non-invasive arterial pulse contour technique (Nexfin(®)) compared with echocardiography.

In this prospective study, cardiac output was measured in 38 intensive care unit patients before and after a fluid challenge, using both pulse contour analysis (Nexfin(®); BMEYE, Amsterdam, the Netherlands) and transthoracic echocardiography. The ability of the Nexfin device to detect significant changes in the velocity-time integral was evaluated. The pulse wave could not be detected by the Nexfin device in five patients (13%), leaving 33 patients for analysis. The Nexfin device adequately tracked changes in the velocity-time integral in 20 (61%) patients. Using a cut-off of a 10% increase in cardiac output estimated by the Nexfin or by echocardiography, the sensitivity of the Nexfin device to detect a response to fluid challenge was 47%, with specificity 81% and accuracy 64%. The percentage error between the Nexfin and echocardiography was 448%; lower limit of agreement -48% (95% CI -62 to -36%) and upper limit of agreement, 32% (95% CI 20-45%). We conclude that the Nexfin device does not adequately track changes in cardiac output in critically ill patients.

[Pseudo-hyperkalemia and hyperleukocytosis]. / Pseudo-hyperkaliémie et hyperleucocytose.

A pseudo-hyperkalemia may occur with hyperleukocytosis. It is important to recognize it early to avoid unnecessary or even dangerous treatment inducing hypokalemia. The pseudohyperkalemia is due to cell fragility coupled to mechanical phenomena during blood collecting. We report a case of pseudo-hyperkalemia in a context of acute myeloid leukemia.

Core competencies in critical care for general medical practitioners in South Africa: A Delphi study.

Background: Despite a high burden of disease that requires critical care services, there are a limited number of intensivists in South Africa (SA). Medical practitioners at district and regional public sector hospitals frequently manage critically ill patients in the absence of intensivists, despite these medical practitioners having had minimal exposure to critical care during their undergraduate training. Objectives: To identify core competencies in critical care for medical practitioners who provide critical care services at public sector hospitals in SA where intensivists are not available to direct patient management. Methods: A preliminary list of core competencies in critical care was compiled. Thereafter, 13 national and international experts were requested to achieve consensus on a final list of core competencies that are required for critical care by medical practitioners, using a modified Delphi process. Results: A final list of 153 core competencies in critical care was identified. Conclusion: The core competencies identified by this study could assist in developing training programmes for medical practitioners to improve the quality of critical care services provided at district and regional hospitals in SA. Contribution of the study: The study provides consensus on a list of core competencies in critical care that non-intensivist medical practitioners managing critically ill patients in healthcare settings in South Africa, especially where intensivists are not readily available, should have. The list can form the core content of training programmes aimed at improving critical care competence of general medical practitioners, and in this way hopefully improve the overall outcomes of critically ill patients in South Africa.

Positive fluid balance is associated with reduced survival in critically ill patients with cancer.

BACKGROUND: There are no studies that describe the impact of the cumulative fluid balance on the outcomes of cancer patients admitted to intensive care units ICUs. The aim of our study was to evaluate the relationship between fluid balance and clinical outcomes in these patients. METHOD: One hundred twenty-two cancer patients were prospectively evaluated for survival during a 30-day period. Univariate (Chi-square, t-test, Mann-Whitney) and multiple logistic regression analyses were used to identify the admission parameters associated with mortality. RESULTS: The mean cumulative fluid balance was significantly higher in non-survivors than in survivors [1675 ml/24 h (471-2921) vs. 887 ml/24 h (104-557), P = 0.017]. We used the area under the curve and the intersection of the sensibility and specificity curves to define a cumulative fluid balance value of 1100 ml/24 h. This value was used in the univariate model. In the multivariate model, the following variables were significantly associated with mortality in cancer patients: the Acute Physiology and Chronic Health Evaluation II score at admission [Odds ratio (OR) 1.15; 95% confidence interval (CI) (1.05-1.26), P = 0.003], the Lung Injury Score at admission [OR 2.23; 95% CI (1.29-3.87), P = 0.004] and a positive fluid balance higher than 1100 ml/24 h at ICU [OR 5.14; 95% CI (1.45-18.24), P = 0.011]. CONCLUSION: A cumulative positive fluid balance higher than 1100 ml/24 h was independently associated with mortality in patients with cancer. These findings highlight the importance of improving the evaluation of these patients' volemic state and indicate that defined goals should be used to guide fluid therapy.

[Magnesium in critical care and anesthesiology]. / Le magnésium, applications en soins intensifs et en anesthésiologie.

Magnesium (Mg) is an essential ion for life and is involved in many important biological processes. Mg deficiency may have serious consequences and has been implicated in many diseases. Assessment of Mg status is difficult because Mg is essentially intracellular and there is no simple, rapid and accurate laboratory test to determine total body Mg. New, non-invasive techniques are being developed that could be used in the near future. Mg therapy is clearly indicated in "torsade de pointes" and preeclampsia. Mg therapy is not recommended in the treatment of acute myocardial infarction, stroke or non-severe acute asthma. Nevertheless, Mg administration may be useful to reduce cerebral ischemic events after aneurysmal subarachnoid hemorrhage or in the treatment of severe acute asthma, specifically in children. Finally, the potential post-operative analgesic effect of Mg is still debated and results from new, larger clinical trials may help clarify this issue. This article reviews physiological functions and pharmacology of Mg status as well as the causes, clinical manifestations, and treatment of Mg deficiency. The possible analgesic effects of Mg in the postoperative period are also reviewed.

Development and Optimization of a Machine-Learning Prediction Model for Acute Desquamation After Breast Radiation Therapy in the Multicenter REQUITE Cohort.

Purpose: Some patients with breast cancer treated by surgery and radiation therapy experience clinically significant toxicity, which may adversely affect cosmesis and quality of life. There is a paucity of validated clinical prediction models for radiation toxicity. We used machine learning (ML) algorithms to develop and optimise a clinical prediction model for acute breast desquamation after whole breast external beam radiation therapy in the prospective multicenter REQUITE cohort study. Methods and Materials: Using demographic and treatment-related features (m = 122) from patients (n = 2058) at 26 centers, we trained 8 ML algorithms with 10-fold cross-validation in a 50:50 random-split data set with class stratification to predict acute breast desquamation. Based on performance in the validation data set, the logistic model tree, random forest, and naïve Bayes models were taken forward to cost-sensitive learning optimisation. Results: One hundred and ninety-two patients experienced acute desquamation. Resampling and cost-sensitive learning optimisation facilitated an improvement in classification performance. Based on maximising sensitivity (true positives), the "hero" model was the cost-sensitive random forest algorithm with a false-negative: false-positive misclassification penalty of 90:1 containing m = 114 predictive features. Model sensitivity and specificity were 0.77 and 0.66, respectively, with an area under the curve of 0.77 in the validation cohort. Conclusions: ML algorithms with resampling and cost-sensitive learning generated clinically valid prediction models for acute desquamation using patient demographic and treatment features. Further external validation and inclusion of genomic markers in ML prediction models are worthwhile, to identify patients at increased risk of toxicity who may benefit from supportive intervention or even a change in treatment plan.

[Hypophosphatemia in critically ill patients]. / Hypophosphorémie chez le malade grave.

Phosphorus is a mineral element essential to cellular function. The prevalence of hypophosphatemia is particularly high in critically ill patients. Hypophosphatemia may be the result of increased renal excretion, reduced digestive absorption, intracellular shift accompanied or not by depletion of the total phosphorus pool, and extreme catabolic states. Clinical manifestations are especially apparent in severe hypophosphatemia and include impairments of the respiratory, musculo-skeletal, pulmonary, and neurological systems. Hypophosphatemia must be corrected, especially if it is severe and symptomatic.

[Thrombocytopenia in the critically ill patient]. / Thrombopénie chez le malade grave.

Thrombocytopenia is associated with increased mortality rates in critically ill patients. It is especially present in cases of sepsis, but can also be caused by medications or associated with the use of foreign materials. Many physiological mechanisms (immune-mediated, consumption or destruction) are involved in the decrease of platelet count. The timing and intensity of the thrombocytopenia and the clinical context can help in the differential diagnosis. The aetiology of the thrombocytopenia must be elucidated in order to optimize the therapeutic management.

[Hyperlactataemia : not only useful in circulatory shock]. / L'hyperlactatémie: pas seulement utile en cas de choc circulatoire.

Hyperlactataemia, a marker of poor prognosis in intensive care patients, is most frequently found in cases of acute circulatory failure ; however, it may be due to factors other than cellular hypoxia. The level of blood lactate is determined by the balance between its production and its elimination, which can be influenced by various factors. For example, the influence of medication on blood lactate levels should not be underestimated, whether in anaesthesiology, with the use of propofol, or with certain anti-retrovirals in HIV seropositive patients. And in oncology, blood lactate can derive from anaerobic metabolism, characteristic of tumour cells. The differential diagnosis of hyperlactataemia can, therefore, sometimes be more complex than initially thought.