Prone positioning for the ARDS patient

Various strategies have been tested in attempts to improve gas exchange in patients with Acute Respiratory Distress Syndrome (ARDS). However, it appears that the simple non-invasive act of prone positioning of the critically ill ARDS patient may improve gas exchange while preventing potential complications of high positive end expiratory pressure (PEEP), volutrauma, and oxygen toxicity.     

Improved oxygenation utilizing a prone positioner in patients with acute respiratory distress syndrome

OBJECTIVES: (a) To determine whether placing patients with acute respiratory distress syndrome in the prone position by a light-weight portable support frame improves oxygenation, (b) whether one can determine which patients benefit from prone positioning, and (c) to determine an effective technique for prone positioning of patients. DESIGN: Prospective, controlled trial without blinding. SETTING: Medical intensive care units in two urban university-affiliated hospitals. PATIENTS: Fifteen patients meeting a standard definition for acute respiratory distress syndrome were studied prospectively. Each patient acted as his own control for purposes of comparison. INTERVENTION: Patients were assigned randomly to begin in either supine or prone positions. The positioning frame was used to turn patients from one position to the other, and oxygenation, ventilation, respiratory mechanics, and hemodynamics were measured. RESULTS: Significantly better oxygenation was seen in the prone positions than in the supine (P < 0.05). In the overall population there was a decrease in AaDO2 of 21 mmHg when the patients were placed prone. The groups were then divided into responders (n = 9) and nonresponders (n = 6). There were significant differences between the groups (but not between positions) regarding PaO2, baseline, PaCO2, pulmonary artery pressures, and peak inspiratory pressures on the ventilator and in ICU length of stay and time on mechanical ventilatory support. CONCLUSION: Prone positioning improves oxygenation in the majority of patients studied and can be achieved relatively easily.     

Software quality assessment and standards

The development of software product-quality assessment methods is reviewed. Much of the software quality standards work has been performed under the aegis of international organizations such as the IEEE Computer Society and the International Standard Organization/International Electrotechnical Committee Joint Technical Committee No.1 Subcommittee on Software Engineering (ISO JTC1 SC7). An alternative approach that defines a set of requirements for members of a class of software product and certifies those that meet the requirements is described     

Grain Boundary Defect Chemistry of Acceptor-Doped Titanates: Space Charge Layer Width

The grain boundary space charge depletion layers in acceptor-doped SrTiO₃ and BaTiO₃ ceramics were investigated by impedance spectroscopy in the time and frequency domain. Based on the layer width and its dependence on the acceptor concentration, the temperature, and the oxygen partial pressure during annealing, a suggestion for a refined Schottky model is proposed. The local distribution of the donor-type grain boundary states causing the depletion layer and the resulting band bending are discussed.     

Early onset group B streptococcal disease: clinical, roentgenographic, and pathologic features

Thirty-one neonates with early onset of serious group B streptococcal infections were observed in a four-year period. The mortality was 52%. Premature infants with clinical signs of respiratory distress syndrome were at highest risk of death; clinical signs of RDS were typical until apnea, shock, respiratory failure, and worsening of the radiographic pattern unexpectedly intervened. Pathologic material from infants with radiographic evidence either of RDS or of pneumonia showed both typical hyaline membrane disease and pneumonia in most instances. Factors which may be helpful in recognizing premature infants at risk for GBS disease in the much larger group of premature infants with uncomplicated RDS include: history of artificial, premature, or prolonged rupture of membranes; localized pulmonary infiltrates on chest roentgenogram; low absolute neutrophil count; and an unusually rapid progression of RDS.