Correlation between field walking tests and postoperative cardiopulmonary complications in patients undergoing lung surgery

Postoperative cardiopulmonary complications are the most common complications following lung surgery, which cause mobility, mortality, and increase the length of hospital stay. It is essential to assess the risk of patients before lung surgery using the field walking test, which was recommended for a similar cardiovascular response to that of the CPET. Objective: To investigate the correlation between the field walking test and postoperative cardiopulmonary complications in patients undergoing lung surgery and to determine the cut-off point of the preoperative field walking test for classifying the risk of postoperative cardiopulmonary complications in patients undergoing lung surgery. Methods: A total of 98 patients who underwent lung surgery. This prospective cohort study performed the field walking test in patients within 48 hours prior to lung surgery. Then, postoperative cardiopulmonary complications are recorded on the first day after surgery and continue until the patients are discharged from the hospital. Result: There is a statistically significant negative correlation between postoperative pulmonary complications and the distance of the endurance shuttle walk test (r=-0.221, p=0.029), the duration of the endurance shuttle walk test (r=-0.353, p<0.001). In addition, the statistically significant negative correlations between postoperative cardiac complications and the 6-minute walk test (r=-0.214, p=0.034), the distance of the endurance shuttle walk test (r=-0.233, p=0.021), and the duration of the endurance shuttle walk test (r=-0.280, p=0.005) are found in the correlation analysis. The diagnostic sensitivity and specificity of the walking tests was evaluated by comparing the postoperative complications. However, the area under the ROC curve in this study failed to take into consideration for a useful diagnostic test (AUC = 0.374, p=0.033). Conclusion: Endurance shuttle walk test are correlated with postoperative pulmonary complications. Also, there is a correlation between the endurance shuttle walk test and the six-minute walk test and postoperative cardiac complications. Therefore, this test can be used as one of the guidelines and standards for screening for the risk of cardiopulmonary complications after surgery.

术后心肺并发症是肺部手术后最常见的并发症类型，可导致患者活动能力下降、病死率升高，并延长住院时长。术前采用户外步行试验（field walking test）评估患者风险具有重要临床价值，该试验因与心肺运动试验（CPET）的心血管反应模式相似而被推荐用于术前评估。
研究目的：探讨户外步行试验与肺部手术患者术后心肺并发症的相关性，并确定术前户外步行试验用于评估肺部手术患者术后心肺并发症风险的截断值。
研究方法：本前瞻性队列研究共纳入98例行肺部手术的患者，所有患者于术前48小时内完成户外步行试验；术后首日起直至患者出院，持续记录其术后心肺并发症发生情况。
研究结果：相关性分析显示，术后肺部并发症与耐力穿梭步行试验（endurance shuttle walk test）的步行距离（r=-0.221，p=0.029）、持续时长（r=-0.353，p<0.001）均存在显著负相关；此外，术后心脏并发症与6分钟步行试验（6-minute walk test）、耐力穿梭步行试验的步行距离及持续时长亦存在显著负相关，具体相关系数分别为r=-0.214（p=0.034）、r=-0.233（p=0.021）及r=-0.280（p=0.005）。本研究通过对比术后并发症发生情况，评估了各类步行试验的诊断灵敏度与特异度，但本研究的受试者工作特征曲线（ROC）下面积（AUC=0.374，p=0.033）未达到临床实用诊断试验的标准。
研究结论：耐力穿梭步行试验与术后肺部并发症存在相关性，同时该试验与6分钟步行试验、术后心脏并发症亦存在相关性。因此，该试验可作为筛查术后心肺并发症风险的参考指标与标准之一。