To determine if decreased respiratory frequency (ventilatory rate) improves indices of lung damage, 17 sets of isolated, perfused rabbit lungs were ventilated with a peak static airway pressure of 30 cm H(2)O. All lungs were randomized to one of three frequency/peak pulmonary artery pressure combinations: F20P35 (n = 6): ventilatory frequency, 20 breaths/min, and peak pulmonary artery pressure, 35 mm Hg; F3P35 (n = 6), ventilatory frequency, 3 breaths/min, and peak pulmonary artery pressure of 35 mm Hg; or F20P20 (n = 5), ventilatory frequency, 20 breaths/min, and peak pulmonary artery pressure, 20 mm Hg. Mean airway pressure and tidal volume were matched between groups. Mean pulmonary artery pressure and vascular flow were matched between groups F20P35 and F3P35. The F20P35 group showed at least a 4.5-fold greater mean weight gain and a 3-fold greater mean incidence of perivascular hemorrhage than did the comparison groups, all p

Propofol (P) and midazolam (M) are frequently given by continuous infusion for sedation in critically ill, mechanically ventilated patients. We compared these drugs with regard to: (1) time-to-awaken; (2) reproducibility of bedside assessments of level of sedation; (3) time-to-sedation; and (4) change in oxygen consumption (V O2) from awake to sedated state. Seventy-three patients were prospectively randomized to receive either P (n=37) or M (n=36). Wake-up times after stopping the drug were assessed by blinded and unblinded observers, by asking patients to perform simple tasks. Times to sedate were assessed by consensus agreement among nurses and investigators. Demographics and APACHE II scores were not different between P and M. The P group had a significantly narrower range of wake-up times with a higher likelihood of waking in less than 60 min. Blinded versus unblinded observations had excellent correlation. Average time to sedate and decrease in V O2 were not different. We conclude that in this patient population: (1) both P and M achieved optimal sedation in a large fraction of patients when administered by specified dosing protocols; (2) P had a faster, more reliable, wake-up time; (3) assessments of time-to-awaken were objective and reproducible; (4) time to sedation was not significantly different; (5) V O2 decreased similarly with both.

In two studies of ventilator-induced lung injury in rabbits, maintaining hyperthermia compared with hypothermia augmented the development of lung injury. Similar results from both the in vivo and isolated, perfused lung studies suggest that the observed effects were not due to cardiovascular factors or consequences of heating nonpulmonary organs.

Explicit emphasis on teaching science process skills leads to both gains in the skills themselves and, strikingly, deeper understanding of content. Here, we created and tested a series of online, interactive tutorials with the goal of helping undergraduate students develop science process skills. We designed the tutorials in accordance with evidence-based multimedia design principles and student feedback from usability testing. We then tested the efficacy of the tutorials in an introductory undergraduate biology class. On the basis of a multivariate ordinary least-squares regression model, students who received the tutorials are predicted to score 0.82 points higher on a 15-point science process skill assessment than their peers who received traditional textbook instruction on the same topic. This moderate but significant impact indicates that well-designed online tutorials can be more effective than traditional ways of teaching science process skills to undergraduate students. We also found trends that suggest the tutorials are especially effective for nonnative English-speaking students. However, due to a limited sample size, we were unable to confirm that these trends occurred due to more than just variation in the student group sampled.

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Explicit emphasis on teaching science process skills leads to both gains in the skills themselves and, strikingly, deeper understanding of content. Here, we created and tested a series of online, interactive tutorials with the goal of helping undergraduate students develop science process skills. We designed the tutorials in accordance with evidence-based multimedia design principles and student feedback from usability testing. We then tested the efficacy of the tutorials in an introductory undergraduate biology class. Based on a multivariate ordinary least squares regression model, students that received the tutorials are predicted to score 0.824 points higher on a 15 point science process skill assessment than their peers that received traditional textbook instruction on the same topic. This moderate but significant impact indicates that well designed online tutorials can be more effective than traditional ways of teaching science process skills to undergraduate students. We also found trends that suggest the tutorials are especially effective for non-native English speaking students. However, due to a limited sample size, we were unable to confirm that these trends occurred due to more than just variation in the sampled student group.