[Follow-up of patients after COVID-19 pneumonia. Pulmonary sequelae]. / Seguimiento de los pacientes después de neumonía por COVID-19. Secuelas pulmonares.

Coronavirus disease 2019 (COVID-19) is an infection caused by SARS-CoV-2 that has caused an unprecedented pandemic with a high rate of morbidity and mortality worldwide. Although most cases are mild, there are a considerable number of patients who develop pneumonia or even acute respiratory distress syndrome (ARDS). After having recovered from the initial disease, many patients continue with various symptoms (fatigue, dry cough, fever, dyspnea, anosmia, and chest pain, among others.), which has led to consider the possible existence of "post-COVID-19 syndrome". Although the definition and validity of this syndrome are not clear yet, several studies report that individuals who have recovered from COVID-19 may have persistent symptoms, radiological abnormalities, and compromised respiratory function. Current evidence suggests that there is a large number of pulmonary sequelae after COVID-19 pneumonia (interstitial thickening, ground glass opacities, crazy paving pattern, and bronchiectasis, among others.). Likewise, it seems that pulmonary function tests (spirometry, DLCO, 6MWT, and measurement of maximum respiratory pressures), in addition to high-resolution computed axial tomographies (CAT scan), are useful for the assessment of these post-COVID-19 pulmonary sequelae. This review aims to describe the possible pulmonary sequelae after COVID-19 pneumonia, as well as to suggest diagnostic procedures for their correct assessment and follow-up; thus, allowing proper management by a multidisciplinary medical team.

COVID-19 es la enfermedad causada por el virus SARS-CoV-2, la cual ha ocasionado una pandemia sin precedentes, con gran cantidad de infectados y muertos en el mundo. Aunque la mayoría de los casos son leves, existe una cantidad considerable de pacientes que desarrollan neumonía o, incluso, síndrome de distrés respiratorio agudo (SDRA). Luego de recuperarse del cuadro inicial, muchos pacientes continúan con diversos síntomas (fatiga, tos seca, fiebre, disnea, anosmia, dolor torácico, entre otras), lo que ha llevado a considerar la posible existencia del "síndrome pos-COVID-19". Aunque la definición y validez de este síndrome aún no son claras, varios estudios reportan que los individuos recuperados de la COVID-19 pueden tener persistencia de síntomas, anormalidades radiológicas y compromiso en la función respiratoria. La evidencia actual sugiere que existe gran cantidad de secuelas pulmonares despues de una neumonía por COVID-19 (engrosamiento intersticial, infiltrado en vidrio esmerilado, patrón en empedrado, bronquiectasias, entre otras.). De igual forma, parece ser que las pruebas de función pulmonar (espirometría, prueba de difusión pulmonar de monóxido de carbono, prueba de caminata de seis minutos y la medición de las presiones respiratorias máximas), además de la tomografía axial computarizada de alta resolución, son útiles para evaluar las secuelas pulmonares pos-COVID-19. En esta revisión se pretende describir las posibles secuelas a nivel pulmonar posteriores a neumonía por COVID-19, así como sugerir procedimientos diagnósticos para su correcta evaluación y seguimiento, que permitan el manejo adecuado por parte de un equipo médico multidisciplinario.

Gas Exchange Impairment During COVID-19 Recovery.

BACKGROUND: Persistent impairment of pulmonary function and exercise capacity has been known to last for months or even years in the survivors who recovered from other coronavirus pneumonia. Some reports showed that subjects with coronavirus disease 2019 pneumonia after being discharged could have several sequelae, but there are few studies on gas exchange and exercise capacity complications in these subjects. AIMS: To describe residual gas exchange abnormalities during recovery from coronavirus disease 2019 pneumonia. METHODS: In an observational study, ∼90 d after onset of disease, we scheduled almost 200 subjects for an out-patient visit with pulmonary function testing and computed tomography of the lungs. Lung mechanics by using body plethysmography, gas exchange with diffusing lung capacity for carbon monoxide determined by the single-breath technique (DLCOsb) and diffusing lung capacity for nitric oxide determined by the single-breath technique (DLNOsb), and exercise ability by using the 6-min walk test (6MWT) were measured in the subjects. The results were compared between those who required invasive mechanical ventilation and those who did not. RESULTS: A total of 171 subjects were included, the majority (96%) had signs of residual pneumonia (such as an excess of high attenuation areas) on computed tomography of the lungs. The DLCOSB results were below the lower limit of the normal range in 29.2% of the subjects; during the 6MWT, 67% experienced oxygen desaturation ([Formula: see text]) > 4%; and, in 81 (47%), the dropped below 88%. Subjects who required invasive mechanical ventilation (49.7%) were more likely to have lower lung volumes, more gas exchange abnormality, less exercise capacity and more radiologic abnormality. CONCLUSIONS: Subjects who recovered from severe COVID-19 pneumonia continued to have abnormal lung function and abnormal radiologic findings.

Functional Respiratory Evaluation in the COVID-19 Era: The Role of Pulmonary Function Test Laboratories.

The pandemic character of coronavirus disease-19 (COVID-19) requires strategy changes designed to guarantee the safety of patients and health-care professionals. We are greatly concerned by the limitations in the operation of pulmonary function test (PFT) laboratories, since there is a high risk of disease progression in patients with chronic pulmonary diseases, and we are now faced by the influx of a new group of individuals in the recovery phase of post-COVID-19-syndrome that requires evaluation and follow-up of their respiratory function. To reestablish the operation of PFT laboratories limiting the risk of cross-contamination, we herein present the consensus reached by a group of experts in respiratory physiology, most of whom work in PFT laboratories in several Latin American countries, on the applicable recommendations for severe acute respiratory syndrome coronavirus 2 pneumonia survivors when undergoing PFT. We present the safety and hygiene measures that must be adopted in laboratories or centers where PFT is conducted in adults and/or children. These recommendations answer the following questions: which PFT is most recommended in subjects that have recovered from COVID-19; what quality control and safety measures should PFT laboratories implement during this pandemic? And how should we approach non-COVID-19 patients requiring PFT?