Pulmonary function tests in preoperative pulmonary evaluation

Decision Thresholds for Medical Tests Under Ambiguity Aversion

We consider medical decision-making under diagnostic and therapeutic uncertainty and analyze how ambiguity aversion affects the decisions to test and treat, thereby contributing to the understanding of the observed heterogeneity of such decisions. We show that under diagnostic ambiguity (i.e., the probability of disease is ambiguous), prior testing becomes more attractive if the default option is no treatment and less so if the default option is treatment. Conversely, with therapeutic ambiguity (i.e., the probability of a successful treatment is ambiguous), ambiguity aversion reduces the tolerance toward treatment failure so that the test option is chosen at a lower probability of failure. We differentiate between conditional and unconditional ambiguity aversion and show that this differentiation has implications for the propensity to test. We conclude by discussing the normative scope of ambiguity aversion for the recommendations and decisions of regulatory bodies.

[Analysis of Postoperative Complications and Risk Factors of Patients with Lung Cancer through Clavien-Dindo Classification]

背景与目的

术后并发症是肺切除术后患者死亡的重要原因。在本研究中，我们应用Clavien-Dindo并发症分级系统对肺癌术后并发症按照严重程度进行分级，并分析术后并发症的发生率，探讨不同分级术后并发症的危险因素。

方法

回顾性分析2013年6月-2014年12月四川大学华西医院胸外科966例行肺叶切除术的肺癌患者，依据术后30 d内是否发生并发症将此966例患者分为并发症组与无并发症组；同时根据Clavien-Dindo分级系统将并发症分为4级，并针对不同分级的并发症进行危险因素分析。

结果

966例患者中，并发症组占15.0%（145/966），发生总数380次；依据Clavien-Dindo分级系统将此380次并发症进行分级，其中Ⅰ级、Ⅱ级、Ⅲ级、Ⅳ级及以上分别占6.8%、75.3%、15.0%和2.9%。Logistic回归分析结果显示术前第1秒用力呼气容积（forded expiratory volume in one second, FEV₁）、肺一氧化碳弥散量（diffusion capacity for carbon monoxide of the lung single breath, DLco SB）及术前合并慢性阻塞性肺疾病（chronic obstructive pulmonary disease, COPD）是术后并发症的独立危险因素；其中术前FEV₁是Ⅰ级、Ⅱ级、Ⅲ级及以上并发症的独立危险因素。

结论

在Clavien-Dindo分级系统下，Ⅱ级并发症在术后30天内最常见；FEV₁与术后并发症的发生密切相关，可作为评估术后并发症发生风险的可靠指标之一。

Diagnostic measures to evaluate oxygenation in critically ill adults: implications and limitations

Accurate assessment and treatment of disturbances in oxygenation are crucial to optimal outcomes in critically ill patients. Oxygenation is dependent upon adequate pulmonary gas exchange, oxygen delivery, and oxygen consumption. Each of these physiologic processes may vary independently in response to pathophysiologic conditions and therapeutic interventions. The author reviews diagnostic measures available to evaluate pulmonary gas exchange, oxygen delivery, and oxygen consumption in critically ill patients. Currently available tools and their potential value as well as key methodological limitations are addressed. Failure on behalf of clinicians to fully appreciate these limitations can lead to misdiagnoses and inappropriate treatment. The aim of this article is to help advanced practice nurses more fully understand the implications and limitations of these diagnostic measures to ensure accurate assessment and treatment of disturbances in oxygenation.