Spatial network sampling in small area estimation

The spatial distribution of a population represents an important in sampling designs where that use the network of the contiguities between units as auxiliary information in the frame. Its use is increased in the last decades as the GIS and GPS technologies made more and more cheap to add information regarding the exact or estimated position for each record in the frame. These data may represent a source of auxiliaries that can be helpful to design effective sampling strategies, which, assuming that the observed phenomenon is related with the spatial features of the population, could gather a considerable gain in their efficiency by a proper use of this particular information. This assumption is particularly relevant if we are dealing with not planned geographical domains or, in other terms, if we want that the design will be efficient for a future use within a small area estimation context. A method for selecting samples from a spatial finite population that are well spread over the population in every dimension should guarantee that the variability of the expected sampling ratio should be smaller than that obtained by using a simple random sampling. Some algorithms of sample selection are presented such that a set of units with higher within distance will be selected with higher probability than a set of nearby units. Some examples on real data show that the RMSE of the EBLUP estimates applied to samples selected with these network methods are lower than those obtained by using a classical solution as the Generalized Random Tessellation Stratified (GRTS). The proposed algorithm, even if in its nature it is computationally intensive, seems to be a feasible solution even when dealing with frames relevant to large finite network populations

Comment on \u201cA new device for administration of continuous positive airway pressure in preterm infants\u201d by Trevisanuto et al

We read with interest the contribution by Trevisanuto et al. [1] on the effectiveness of a new device for administering continuous positive airway pressure (CPAP) as an alternative to conventional nasal CPAP in ameliorating comfort in preterm infants needing continuous distending pressure. The data which they present are intriguing, but a few points need to be further discussed. First, the use of a \u201ccomfort scale\u201d appears to be a surrogate end-point. To properly assess safety and efficacy of this new technique, even in a pilot study, the authors should have focused on more relevant clinical aspects or potential complications, such as level of respiratory distress, oxygen-dependency, rate of apnea, local damage, air leak, or need for mechanical ventilation. Second, the authors reported a marked reduction in the Neonatal Infant Pain Scale (NIPS) values, i.e., a better comfort status of patients, during treatment with helmet CPAP. Given the lower level of stress imposed by this technique, one might have expected some modifications in the main physiological parameters, such as heart rate, respiratory rate, and arterial blood pressure [2]. On the other hand, none of the investigated parameters differed between the two CPAP treatments, raising doubts about potential bias due to the nonblinded scoring method used in this study. Indeed, NIPS does require a close observation of the infant, making any blinding process quite complex. Such important limitation might be partially circumvented by simultaneous NIPS measurements performed by two independent observers or by video recording. Third, the small number of enrolled patients (powered only for the chosen end-point), the very brief duration of both CPAP treatments, and the relatively healthy status of the population studied preclude any definitive conclusion about this study. Indeed, how would this technique work in sicker infants who may require CPAP continuously for days or weeks? What are the possible effects of long-term application on abdominal distension, or in the prevention of apnea episodes? As regards the latter point, we have had the contrary findings in a single preliminary experience. A premature infant (31weeks of postconceptional age) treated with conventional nasal CPAP (Infant-Flow-Driver, EME) for apnea of prematurity, was shifted to helmet CPAP due to poor tolerance of nasal prongs. However, after 2 h of treatment he had to be returned to nasal CPAP for repeated episodes of apnea and arterial O2 desaturation. Interestingly, as soon as conventional nasal CPAP was applied, the apneic episodes virtually disappeared. Of note, we report some difficulties in maintaining CPAP levels above 3 cmH2O, despite flow rates set as high as 15 lpm and absence of major leaks in the system. We speculate that conventional nasal CPAP, successfully used for apnea of prematurity [3], would be more effective than the new technique in these circumstances. In summary, we congratulate the authors for their original study. Nonetheless, their conclusion that the helmet CPAP \u201cseems to guarantee a better tolerability and at least similar improvement in oxygenation\u201d may be misleading for the reader. We believe that larger randomized controlled studies are needed to better define the role of this new device and to verify its potential superiority over conventional CPAP by means of more appropriate end-points

Processos de estamparia têxtil

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Postpneumonectomy-Like Syndrome in an Infant With Right Lung Agenesis and Left Main Bronchus Hypoplasia

We report a 1-year-old child born with agenesis of the right lung who sustained an episode of acute respiratory failure related to a postpneumonectomy-like syndrome, with severe mediastinal shift and subsequent stretching and stenosis of the left main bronchus. The insertion of an expandable prosthesis in the right empty pleural space markedly improved the patient's clinical condition

Understanding the Private Worlds of Physicians, Nurses, and Parents: A Study of Life-Sustaining Treatment Decisions in Italian Paediatric Critical Care

This study's aim was to describe: (a) How life-sustaining treatment (LST) decisions are made for critically ill children in Italy; and (b) How these decisional processes are experienced by physicians, nurses and parents. Focus groups with 16 physicians and 26 nurses, and individual interviews with 9 parents were conducted. Findings uncovered the 'private worlds' of paediatric intensive care unit (PICU) physicians, nurses and parents; they all suffer tremendously and privately. Physicians struggle with the weight of responsibility and solitude in making LST decisions. Nurses struggle with feelings of exclusion from decisions regarding patients and families that they care for. Physicians and nurses are distressed by legal barriers to LST withdrawal. Parents struggle with their dependence on physicians and nurses to provide care for their child and strive to understand what is happening to their child. Features of helpful and unhelpful communication with parents are highlighted, which should be considered in educational and practice changes

Severe bleeding from esophageal varices resistant to endoscopic treatment in a non cirrhotic patient with portal hypertension

A non cirrhotic patient with esophageal varices and portal vein thrombosis had recurrent variceal bleeding unsuccessfully controlled by endoscopy and esophageal transection. Emergency transhepatic portography confirmed the thrombosed right branch of the portal vein, while the left branch appeared angulated, shifted and stenotic. A stent was successfully implanted into the left branch and the collateral vessels along the epatoduodenal ligament disappeared. In patients with esophageal variceal hemorrhage and portal thrombosis if endoscopy fails, emergency esophageal transection or nonselective portocaval shunting are indicated. The rare patients with only partial portal thrombosis can be treated directly with stenting through an angioradiologic approach

Clinical effects of laparotomy with perioperative continuous peritoneal lavage and postoperative hemofiltration in patients with severe acute pancreatitis

<p>Abstract</p> <p>Background</p> <p>The elevated serum and peritoneal cytokine concentrations responsible for the systemic response syndrome (SIRS) and multiorgan failure in patients with severe acute pancreatitis lead to high morbidity and mortality rates. Prompted by reports underlining the importance of reducing circulating inflammatory mediators in severe acute pancreatitis, we designed this study to evaluate the efficiency of laparotomy followed by continuous perioperative peritoneal lavage combined with postoperative continuous venovenous diahemofiltration (CVVDH) in managing critically ill patients refractory to intensive care therapy. As the major clinical outcome variables we measured morbidity, mortality and changes in the Acute Physiology and Chronic Health Evaluation (APACHE II) score and cytokine concentrations in serum and peritoneal lavage fluid over time.</p> <p>Methods</p> <p>From a consecutive group of 23 patients hospitalized for acute pancreatitis, we studied 6 patients all with Apache II scores ≥19, who underwent emergency surgery for acute complications (5 for an abdominal compartment syndrome and 1 for septic shock) followed by continuous perioperative peritoneal lavage and postoperative CVVDH. CVVDH was started within 12 hours after surgery and maintained for at least 72 hours, until the multiorgan dysfunction syndrome improved. Samples were collected from serum, peritoneal lavage fluid and CVVDH dialysate for cytokine assay. Apache II scores were measured daily and their association with cytokine levels was assessed.</p> <p>Results</p> <p>All six patients tolerated CVVDH well, and the procedure lasted a mean 6 days (range, 3-12). Five patients survived and one died of Acinetobacter infection after surgery (mortality rate 16.6%). The mean APACHE II score was ≥ 19 (range 19-22) before laparotomy and decreased significantly during peritoneal lavage and postoperative CVVDH (P = 0.013 by matched-pairs Students <it>t</it>-test). The decrease in cytokine concentrations in serum and lavage fluid was associated with the decrease in APACHE II scores and high interleukin 6 (IL-6) and tumor necrosis factor (TNF) concentrations in the hemofiltrate.</p> <p>Conclusion</p> <p>In critically ill patients with abdominal compartment syndrome, septic shock or high APACHE II scores related to severe acute pancreatitis, combining emergency laparotomy with continuous perioperative peritoneal lavage followed by postoperative CVVHD effectively reduces the local and systemic cytokines responsible for multiorgan dysfunction syndrome thus improving patients' outcome.</p