Internal Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
Allergy, Pulmonary, & Critical Care Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA.
BMJ Open Respir Res. 2020 Dec;7(1). doi: 10.1136/bmjresp-2020-000667.
Therapeutic thoracentesis is among the most frequently performed medical procedures. Chest discomfort is a common complication and has been associated with increasingly negative pleural pressure as fluid is withdrawn in the setting of non-expendable lung. Visual analogue scales (VASs) are commonly employed to measure changes in discomfort and dyspnoea related to pleural interventions. The minimal clinically important difference (MCID), defined as the smallest change in VAS score associated with patient report of significant change in a symptom, is required to interpret the results of studies using VAS scores and is used in clinical trial power calculations. The MCID for chest discomfort in patients undergoing pleural interventions has not been determined.
Prospectively collected data from two recent randomised trials of therapeutic thoracentesis were used for this investigation. Adult patients with symptomatic pleural effusions referred for therapeutic thoracentesis were enrolled across ten US academic medical centres. Patients were asked to rate their level of chest discomfort on 100 mm VAS before, during and following thoracentesis. Patients then completed a 7-point Likert scale indicating the significance of any change in chest discomfort from preprocedure to postprocedure. The mean difference between discomfort 5 min postprocedure and discomfort just prior to the start of pleural fluid drainage was categorised by Likert scale response.
Data from a total of 262 thoracenteses were included in the analysis. Thirty-four of 262 patients experienced a 'small but significant increase' or a 'large or moderate increase' in discomfort following thoracentesis. The mean increase in VAS score in those reporting a 'small but significant increase' in chest discomfort (n=23) was 16 mm (SD 22.44, 95% CI 6.87 to 25.21).
The MCID for thoracentesis-related chest discomfort measured by 100 mm VAS is 16 mm. This MCID specific to discomfort resulting from pleural fluid interventions can inform the design and analysis of future pleural intervention studies.
治疗性胸腔穿刺术是最常进行的医疗程序之一。胸部不适是一种常见的并发症，并且与非扩张性肺中抽出液体时胸膜压力的逐渐下降有关。视觉模拟量表（VAS）常用于测量与胸膜介入相关的不适和呼吸困难的变化。最小临床重要差异（MCID）是指与患者报告的症状显著变化相关的 VAS 评分的最小变化，需要解释使用 VAS 评分进行的研究结果，并用于临床试验的效能计算。尚未确定接受胸膜介入治疗的患者的胸部不适的 MCID。
本研究使用了两项最近的治疗性胸腔穿刺术随机试验的前瞻性收集数据。来自十个美国学术医疗中心的有症状胸腔积液的成年患者接受了治疗性胸腔穿刺术。在胸腔穿刺术前、术中及术后，患者使用 100mm VAS 评估其胸部不适程度。然后，患者使用 7 分 Likert 量表表示术前至术后胸部不适程度变化的重要程度。术后 5 分钟时与刚开始引流胸腔积液时相比，VAS 评分的平均差异按 Likert 量表反应进行分类。
共纳入了 262 例胸腔穿刺术的数据进行分析。34 例患者（262 例中的 13.6%）在胸腔穿刺术后经历了“小但显著增加”或“大或中度增加”的不适。报告胸部不适“小但显著增加”的患者（n=23）的 VAS 评分平均增加 16mm（SD 22.44，95%CI 6.87 至 25.21）。
VAS 测量的胸腔穿刺术相关胸部不适的 MCID 为 16mm。这一 MCID 是针对胸膜液干预引起的不适而确定的，可为未来的胸膜介入研究的设计和分析提供参考。
