Department of Pulmonary/Sleep and Critical Care Medicine, Walter Reed National Military Medical Center, Bethesda, Maryland, USA.
Department of Medicine, Walter Reed National Military Medical Center, Bethesda, Maryland, USA.
Physiol Rep. 2024 Feb;12(3):e15934. doi: 10.14814/phy2.15934.
Studies using cardiopulmonary exercise testing (CPET) to evaluate persistent dyspnea following infection with COVID-19 have focused on older patients with co-morbid diseases who are post-hospitalization. Less attention has been given to younger patients with post-COVID-19 dyspnea treated as outpatients for their acute infection. We sought to determine causes of persistent dyspnea in younger patients recovering from acute COVID-19 infection that did not require hospitalization. We collected data on all post-COVID-19 patients who underwent CPET in our clinic in the calendar year 2021. Data on cardiac function and respiratory response were abstracted, and diagnoses were assigned using established criteria. CPET data on 45 patients (238.3 ± 124 days post-test positivity) with a median age of 27.0 (22.0-40.0) were available for analysis. All but two (95.6%) were active-duty service members. The group showed substantial loss of aerobic capacity-average VO peak (L/min) was 84.2 ± 23% predicted and 25 (55.2%) were below the threshold for normal. Spirometry, diffusion capacity, high-resolution computed tomography, and echocardiogram were largely normal and were not correlated with VO peak. The two most common contributors to dyspnea and exercise limitation following comprehensive evaluation were deconditioning and dysfunctional breathing (DB). Younger active-duty military patients with persistent dyspnea following outpatient COVID-19 infection show a substantial reduction in aerobic capacity that is not driven by structural cardiopulmonary disease. Deconditioning and DB breathing are common contributors to their exercise limitation. The chronicity and severity of symptoms accompanied by DB could be consistent with an underlying myopathy in some patients, a disorder that cannot be differentiated from deconditioning using non-invasive CPET.
使用心肺运动测试 (CPET) 评估 COVID-19 感染后持续性呼吸困难的研究主要集中在因合并症而住院后出院的老年患者身上。对于因急性 COVID-19 感染而接受门诊治疗的年轻 COVID-19 后呼吸困难患者，关注度较低。我们旨在确定不需要住院治疗的年轻 COVID-19 后急性感染患者持续性呼吸困难的原因。我们收集了 2021 年在我们诊所接受 CPET 的所有 COVID-19 后患者的数据。提取了心脏功能和呼吸反应的数据，并使用既定标准分配诊断。45 名患者（CPET 后中位时间为 238.3±124 天）的 CPET 数据可用于分析，中位年龄为 27.0（22.0-40.0）。除两人外，其余患者均为现役军人（95.6%）。该组的有氧能力明显下降-平均 VO 峰值（L/min）为 84.2±23%预测值，25 例（55.2%）低于正常阈值。肺量计、弥散能力、高分辨率计算机断层扫描和超声心动图基本正常，与 VO 峰值无相关性。全面评估后呼吸困难和运动受限的两个最常见原因是失健和呼吸功能障碍（DB）。门诊 COVID-19 感染后持续性呼吸困难的年轻现役军人患者，其有氧能力明显下降，而不是由结构性心肺疾病引起的。失健和 DB 呼吸是导致其运动受限的常见原因。一些患者的 DB 可能伴有症状的慢性和严重程度以及潜在的肌病，这种疾病无法通过无创 CPET 与失健区分开来。
