Lung-Protective Ventilation.

Historically, mechanical ventilation of the lungs utilizing relatively large tidal volumes was common practice in the operating room and intensive care unit (ICU). The rationale behind this treatment strategy was to yield better patient outcomes, that is, fewer pulmonary complications, and a reduction in morbidity and mortality. As evidence-based practice has evolved, potential harmful effects of traditional, nonphysiological mechanical ventilation (ventilation with larger tidal volumes and the tolerance of high airway pressures) even in shortterm treatment have been shown to correlate with systemic inflammation and the development of ventilator-associated lung injury. Lung-protective ventilation principles using more physiological tidal volumes, avoiding high inspiratory plateau pressures, along with appropriate levels of positive end-expiratory pressure have been shown to decrease pulmonary complications and improve outcomes in patients with acute respiratory distress syndrome requiring ongoing ventilatory support in the ICU. In addition, current research is beginning to validate the benefit of providing more physiologic ventilator support in the operating room, particularly for high-risk patients undergoing major abdominal surgery, in minimizing acute lung injury. A review of lung-protective ventilation measures including benefits and potential side effects is presented. Additional treatment modalities and therapeutic considerations are offered for inclusion in optimal patient management.

Comparison of a visual to a computer-assisted technique for detecting apoptosis.

In many studies, fluorescent dyes (ethidium bromide [EB] and acridine orange [AO]) are used to stain DNA to determine if nuclei are apoptotic. However, there are numerous visual methods for counting these stained DNA that may lead to inaccuracies Measuring apoptosis by the visual counting method may be imprecise because of the variability of individuals' perception of color. Therefore, the authors compared a visual method of counting chromatin for apoptosis with a method relying on a computer program. They began counting chromatin using the visual method, in which individuals identify the stained DNA using their own visual perception. For comparison, they used a software-based counting method (analySIS software) to determine the color (hue) of the stained DNA. Using the numeric hue values from the software eliminates the variations in human color perception. Intra and interrater reliability of the visual and computer-assisted counting methods were evaluated with Spearman's. The authors found statistical significance in the intrarater reliability (r = 1.0, P = 0.0001 for all chromatin categories) and interrater reliability (r = 0.975, P = 0.005 for both readings) when using the software program. No statistical significance was found for the visual counting method, indicating inaccuracy between and within raters. Thus, the computer-assisted counting method of identifying the damaged DNA is more accurate and precise than the individual's visual perception of color. Based on these data, apoptosis measurements using color staining with EB and AO should be determined using hue values generated by a computer program and not by a researcher's visual assessment.