Universidad Espíritu Santo, Km. 2.5 Vía La Puntilla, Samborondón, 0901-952, Ecuador.
Respiralab, Respiralab Research Group, Guayaquil, Ecuador.
J Med Case Rep. 2023 Sep 11;17(1):386. doi: 10.1186/s13256-023-04113-7.
Small airways disease (SAD), a novel finding described in post-acute COVID-19 patients, should be suspected when respiratory symptoms continue, air trapping persists on expiratory CT scans, and imaging findings fail to improve despite objectively better conventional pulmonary function test (PFT) parameters. The forced oscillation technique (FOT) and Multiple breathing washout (MBW) are both very sensitive methods for detecting anomalies in the peripheral airways.
We discuss the case of a 60-year-old Hispanic patient who had severe COVID-19 pneumonia and developed dyspnea, fatigue, and limited daily activity a year later. The PFTs revealed restrictive lung disease, as seen by significant diffusing capacity of the lungs for carbon monoxide (DLCO) decrease, severe desaturation, and poor 6-min walk test (6MWT) performance. The patient was treated with lowering corticosteroids as well as pulmonary rehabilitation (PR). During the 24-month follow-up, the dyspnea and fatigue persisted. On PFTs, 6MWT performance and restricted pattern improved slightly, but MBW discovered significant ventilatory inhomogeneity. FOT revealed substantial peripheral airway obstructive abnormalities. On CT scans, air trapping and ground-glass opacities (GGO) improved somewhat. The patient used a bronchodilator twice a day and low-dose inhaled corticosteroids (160 µg of budesonide and 4.5 µg of formoterol fumarate dihydrate) for nine months. PR sessions were resuming. The restricting parameters were stabilized and the DLCO had normalized after 36 months, with a 6MWT performance of 87% but significant desaturation. The CT scan revealed traction bronchiectasis, low GGO, and persistent air trapping. Without normalization, FOT and MBW scores improved, indicating small airway disease.
The necessity of integrating these tests when detecting SAD is emphasized in our paper. This article lays the foundation for future research into the best ways to manage and monitor SAD in post-acute COVID-19 patients.
小气道疾病（SAD）是一种在急性 COVID-19 后患者中描述的新发现，如果出现以下情况，应怀疑存在 SAD：呼吸症状持续存在、呼气 CT 扫描显示空气滞留、尽管常规肺功能测试（PFT）参数客观改善，但影像学结果无改善。强迫振荡技术（FOT）和多次呼吸清除（MBW）都是检测外周气道异常的非常敏感的方法。
我们讨论了一位 60 岁的西班牙裔患者的病例，他患有严重的 COVID-19 肺炎，一年后出现呼吸困难、疲劳和日常活动受限。PFT 显示为限制性肺病，表现为一氧化碳弥散量（DLCO）显著降低、严重低氧血症和 6 分钟步行测试（6MWT）表现不佳。患者接受了降低皮质激素和肺康复（PR）治疗。在 24 个月的随访中，呼吸困难和疲劳持续存在。在 PFT 上，6MWT 表现和限制性模式略有改善，但 MBW 发现显著的通气不均一性。FOT 显示出显著的外周气道阻塞异常。在 CT 扫描上，空气滞留和磨玻璃影（GGO）有所改善。患者每天使用支气管扩张剂两次，并使用低剂量吸入皮质激素（布地奈德 160µg 和富马酸福莫特罗二水合物 4.5µg）治疗 9 个月。PR 课程正在恢复。限制参数稳定，DLCO 在 36 个月后恢复正常，6MWT 表现为 87%，但仍存在显著低氧血症。CT 扫描显示牵引性支气管扩张、低 GGO 和持续的空气滞留。尽管未恢复正常，但 FOT 和 MBW 评分有所改善，表明存在小气道疾病。
本文强调了在检测 SAD 时整合这些测试的必要性。本文为研究急性 COVID-19 后患者的 SAD 最佳管理和监测方法奠定了基础。
