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Background: Although a high fraction of inspired oxygen (FIO2) could reduce surgical site infection, there is concern it could increase postoperative pulmonary complications, including hypoxemia. Intraoperative positive end-expiratory pressure can improve postoperative pulmonary function. A practical measure of postoperative pulmonary function and the degree of hypoxemia is supplemental oxygen requirement. We performed a double-blind randomized 2 × 2 factorial study on the effects of intraoperative FIO2 0.3 versus more than 0.9 with and without positive end-expiratory pressure on the primary outcome of postoperative supplemental oxygen requirements in patients undergoing lower risk surgery., Methods: After Institutional Review Board approval and consent, 100 subjects were randomized using computer-generated lists into four treatment groups (intraoperative FIO2 0.3 vs. more than 0.9, with and without 3-5 cm H2O positive end-expiratory pressure). Thirty minutes and 24 h after extubation, supplemental oxygen was discontinued. Arterial oxygen saturation by pulse oximetry was recorded 15 min later. If oxygen saturation decreased to less than 90%, supplemental oxygen was added incrementally to maintain saturation more than 90%., Results: Nearly all subjects required supplemental oxygen in the postanesthesia care unit. Nonparametric Wilcoxon rank sum test demonstrated no statistically significant difference between groups in supplemental oxygen requirements at 45 min and 24 h after tracheal extubation (P = 0.56 and 0.98, respectively)., Conclusions: Use of intraoperative FIO2 more than 0.9 was not associated with increased oxygen requirement, suggesting it does not induce postoperative hypoxemia beyond anesthetic induction and surgery. Therefore, it may be reasonable to use high inspired oxygen in surgical patients with relatively normal pulmonary function. more...

Background: Distant healing intention (DHI) is one of the most common complementary and alternative medicine (CAM) healing modalities, but clinical trials to date have provided ambivalent support for its efficacy. One possible reason is that DHI effects may involve variables that are sensitive to unknown, uncontrolled, or uncontrollable factors., Objective: To examine 2 of those potential variables-expectation and belief-we explored the effects of DHI on objective and psychosocial measures associated with surgical wounds in 72 women undergoing plastic surgery., Design: Participants were randomly assigned to 1 of 3 groups: blinded and receiving DHI (DH), blinded and not receiving DHI (control), and knowing that they were receiving DHI (expectancy). Outcome measures included collagen deposition in a surrogate wound and several self-report measures. DHI was provided by experienced distant healers. No differences in the main measures were observed across the three groups., Results: Participants' previous belief in the efficacy of DHI was negatively correlated with the status of their mental health at the end of the study (P = .04, 2-tailed), and healers' perceptions of the quality of their subjective "contact" with the participants were negatively correlated both with change in mood (P = .001) and with collagen deposition (P = .04). A post-hoc analysis found that among participants assigned to receive DHI under blinded conditions, those undergoing reconstructive surgery after breast cancer treatment reported significantly better change in mood than those who were undergoing purely elective cosmetic surgery (P = .004)., Conclusion: If future DHI experiments confirm the post-hoc observations, then some of the ambiguity observed in earlier DHI studies may be attributable to interactions among participants' and healers' beliefs, their expectations, and their motivations., (Copyright © 2012 Elsevier Inc. All rights reserved.) more...

Hypothesis: Women deposit more collagen after major abdominal surgery than men., Design: A post hoc analysis of data obtained from 2 prospective, randomized, double-blind clinical trials., Setting: University hospital general surgical service., Patients: One hundred sixteen patients undergoing colon resection., Main Outcome Measures: Protein and hydroxyproline (collagen) deposition during the first 7 postoperative days in expanded polytetrafluoroethylene implants positioned subcutaneously., Results: On univariate analysis, men and women deposited comparable amounts of collagen (257 +/- 120 vs 281 +/- 117 ng/mm, respectively). When potential confounding factors were entered into a generalized mixed-effects model, only the interaction between age and sex was a significant factor (P = .047). Collagen deposition decreased with age in men, being 317 +/- 133 ng/mm in men younger than 45 years, but only 238 +/- 113 ng/mm in those older than 45 years (P = .03). In contrast, collagen deposition was virtually identical in women younger than 45 years (280 +/- 133 ng/mm) and in those older than 45 years (281 +/- 110 ng/mm). Only 3 of these women were receiving hormone replacement therapy., Conclusions: Collagen deposition after surgery decreased significantly with age in men, while remaining unchanged in women. Younger men and women deposited similar amounts of collagen. Therefore, older men made less collagen after surgery than older women, perhaps explaining the consistent observation that wound dehiscence is twice as common in men than in women. Our results differ from previous studies conducted in healthy, nonsurgical volunteers, which showed that (1) young women made significantly more collagen than young men and (2) collagen deposition was reduced in postmenopausal women, but deposition returned to premenopausal values with hormone replacement therapy. Differences between our results and those reported previously likely stem from the populations studied. In particular, multiple perioperative factors decrease collagen deposition, which apparently obscures the differences observed previously in healthy, unstressed volunteers. more...